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: 1 = Valid length
168 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
169 __u16 required_length
)
171 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
173 if (unlikely(chunk_length
< required_length
))
179 /**********************************************************
180 * These are the state functions for handling chunk events.
181 **********************************************************/
184 * Process the final SHUTDOWN COMPLETE.
186 * Section: 4 (C) (diagram), 9.2
187 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
188 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
189 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
190 * should stop the T2-shutdown timer and remove all knowledge of the
191 * association (and thus the association enters the CLOSED state).
193 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
194 * C) Rules for packet carrying SHUTDOWN COMPLETE:
196 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
197 * if the Verification Tag field of the packet matches its own tag and
198 * the T bit is not set
200 * it is set to its peer's tag and the T bit is set in the Chunk
202 * Otherwise, the receiver MUST silently discard the packet
203 * and take no further action. An endpoint MUST ignore the
204 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
207 * (endpoint, asoc, chunk)
210 * (asoc, reply_msg, msg_up, timers, counters)
212 * The return value is the disposition of the chunk.
214 sctp_disposition_t
sctp_sf_do_4_C(struct net
*net
,
215 const struct sctp_endpoint
*ep
,
216 const struct sctp_association
*asoc
,
217 const sctp_subtype_t type
,
219 sctp_cmd_seq_t
*commands
)
221 struct sctp_chunk
*chunk
= arg
;
222 struct sctp_ulpevent
*ev
;
224 if (!sctp_vtag_verify_either(chunk
, asoc
))
225 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
227 /* RFC 2960 6.10 Bundling
229 * An endpoint MUST NOT bundle INIT, INIT ACK or
230 * SHUTDOWN COMPLETE with any other chunks.
232 if (!chunk
->singleton
)
233 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
235 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
236 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
237 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
240 /* RFC 2960 10.2 SCTP-to-ULP
242 * H) SHUTDOWN COMPLETE notification
244 * When SCTP completes the shutdown procedures (section 9.2) this
245 * notification is passed to the upper layer.
247 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
248 0, 0, 0, NULL
, GFP_ATOMIC
);
250 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
253 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
254 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
255 * not the chunk should be discarded. If the endpoint is in
256 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
257 * T2-shutdown timer and remove all knowledge of the
258 * association (and thus the association enters the CLOSED
261 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
262 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
264 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
265 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
267 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
268 SCTP_STATE(SCTP_STATE_CLOSED
));
270 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
271 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
273 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
275 return SCTP_DISPOSITION_DELETE_TCB
;
279 * Respond to a normal INIT chunk.
280 * We are the side that is being asked for an association.
282 * Section: 5.1 Normal Establishment of an Association, B
283 * B) "Z" shall respond immediately with an INIT ACK chunk. The
284 * destination IP address of the INIT ACK MUST be set to the source
285 * IP address of the INIT to which this INIT ACK is responding. In
286 * the response, besides filling in other parameters, "Z" must set the
287 * Verification Tag field to Tag_A, and also provide its own
288 * Verification Tag (Tag_Z) in the Initiate Tag field.
290 * Verification Tag: Must be 0.
293 * (endpoint, asoc, chunk)
296 * (asoc, reply_msg, msg_up, timers, counters)
298 * The return value is the disposition of the chunk.
300 sctp_disposition_t
sctp_sf_do_5_1B_init(struct net
*net
,
301 const struct sctp_endpoint
*ep
,
302 const struct sctp_association
*asoc
,
303 const sctp_subtype_t type
,
305 sctp_cmd_seq_t
*commands
)
307 struct sctp_chunk
*chunk
= arg
;
308 struct sctp_chunk
*repl
;
309 struct sctp_association
*new_asoc
;
310 struct sctp_chunk
*err_chunk
;
311 struct sctp_packet
*packet
;
312 sctp_unrecognized_param_t
*unk_param
;
316 * An endpoint MUST NOT bundle INIT, INIT ACK or
317 * SHUTDOWN COMPLETE with any other chunks.
320 * Furthermore, we require that the receiver of an INIT chunk MUST
321 * enforce these rules by silently discarding an arriving packet
322 * with an INIT chunk that is bundled with other chunks.
324 if (!chunk
->singleton
)
325 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
327 /* If the packet is an OOTB packet which is temporarily on the
328 * control endpoint, respond with an ABORT.
330 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
331 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
332 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
335 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
338 if (chunk
->sctp_hdr
->vtag
!= 0)
339 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
341 /* Make sure that the INIT chunk has a valid length.
342 * Normally, this would cause an ABORT with a Protocol Violation
343 * error, but since we don't have an association, we'll
344 * just discard the packet.
346 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
347 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
349 /* If the INIT is coming toward a closing socket, we'll send back
350 * and ABORT. Essentially, this catches the race of INIT being
351 * backloged to the socket at the same time as the user isses close().
352 * Since the socket and all its associations are going away, we
353 * can treat this OOTB
355 if (sctp_sstate(ep
->base
.sk
, CLOSING
))
356 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
358 /* Verify the INIT chunk before processing it. */
360 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
361 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
363 /* This chunk contains fatal error. It is to be discarded.
364 * Send an ABORT, with causes if there is any.
367 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
368 (__u8
*)(err_chunk
->chunk_hdr
) +
369 sizeof(sctp_chunkhdr_t
),
370 ntohs(err_chunk
->chunk_hdr
->length
) -
371 sizeof(sctp_chunkhdr_t
));
373 sctp_chunk_free(err_chunk
);
376 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
377 SCTP_PACKET(packet
));
378 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
379 return SCTP_DISPOSITION_CONSUME
;
381 return SCTP_DISPOSITION_NOMEM
;
384 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
389 /* Grab the INIT header. */
390 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
392 /* Tag the variable length parameters. */
393 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
395 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
399 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
400 sctp_scope(sctp_source(chunk
)),
404 /* The call, sctp_process_init(), can fail on memory allocation. */
405 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
406 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
410 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
412 /* If there are errors need to be reported for unknown parameters,
413 * make sure to reserve enough room in the INIT ACK for them.
417 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
418 sizeof(sctp_chunkhdr_t
);
420 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
424 /* If there are errors need to be reported for unknown parameters,
425 * include them in the outgoing INIT ACK as "Unrecognized parameter"
429 /* Get the "Unrecognized parameter" parameter(s) out of the
430 * ERROR chunk generated by sctp_verify_init(). Since the
431 * error cause code for "unknown parameter" and the
432 * "Unrecognized parameter" type is the same, we can
433 * construct the parameters in INIT ACK by copying the
436 unk_param
= (sctp_unrecognized_param_t
*)
437 ((__u8
*)(err_chunk
->chunk_hdr
) +
438 sizeof(sctp_chunkhdr_t
));
439 /* Replace the cause code with the "Unrecognized parameter"
442 sctp_addto_chunk(repl
, len
, unk_param
);
443 sctp_chunk_free(err_chunk
);
446 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
448 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
451 * Note: After sending out INIT ACK with the State Cookie parameter,
452 * "Z" MUST NOT allocate any resources, nor keep any states for the
453 * new association. Otherwise, "Z" will be vulnerable to resource
456 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
458 return SCTP_DISPOSITION_DELETE_TCB
;
461 sctp_association_free(new_asoc
);
464 sctp_chunk_free(err_chunk
);
465 return SCTP_DISPOSITION_NOMEM
;
469 * Respond to a normal INIT ACK chunk.
470 * We are the side that is initiating the association.
472 * Section: 5.1 Normal Establishment of an Association, C
473 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
474 * timer and leave COOKIE-WAIT state. "A" shall then send the State
475 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
476 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
478 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
479 * DATA chunks, but it MUST be the first chunk in the packet and
480 * until the COOKIE ACK is returned the sender MUST NOT send any
481 * other packets to the peer.
483 * Verification Tag: 3.3.3
484 * If the value of the Initiate Tag in a received INIT ACK chunk is
485 * found to be 0, the receiver MUST treat it as an error and close the
486 * association by transmitting an ABORT.
489 * (endpoint, asoc, chunk)
492 * (asoc, reply_msg, msg_up, timers, counters)
494 * The return value is the disposition of the chunk.
496 sctp_disposition_t
sctp_sf_do_5_1C_ack(struct net
*net
,
497 const struct sctp_endpoint
*ep
,
498 const struct sctp_association
*asoc
,
499 const sctp_subtype_t type
,
501 sctp_cmd_seq_t
*commands
)
503 struct sctp_chunk
*chunk
= arg
;
504 sctp_init_chunk_t
*initchunk
;
505 struct sctp_chunk
*err_chunk
;
506 struct sctp_packet
*packet
;
508 if (!sctp_vtag_verify(chunk
, asoc
))
509 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
512 * An endpoint MUST NOT bundle INIT, INIT ACK or
513 * SHUTDOWN COMPLETE with any other chunks.
515 if (!chunk
->singleton
)
516 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
518 /* Make sure that the INIT-ACK chunk has a valid length */
519 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
520 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
522 /* Grab the INIT header. */
523 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
525 /* Verify the INIT chunk before processing it. */
527 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
528 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
531 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
533 /* This chunk contains fatal error. It is to be discarded.
534 * Send an ABORT, with causes. If there are no causes,
535 * then there wasn't enough memory. Just terminate
539 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
540 (__u8
*)(err_chunk
->chunk_hdr
) +
541 sizeof(sctp_chunkhdr_t
),
542 ntohs(err_chunk
->chunk_hdr
->length
) -
543 sizeof(sctp_chunkhdr_t
));
545 sctp_chunk_free(err_chunk
);
548 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
549 SCTP_PACKET(packet
));
550 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
551 error
= SCTP_ERROR_INV_PARAM
;
555 /* SCTP-AUTH, Section 6.3:
556 * It should be noted that if the receiver wants to tear
557 * down an association in an authenticated way only, the
558 * handling of malformed packets should not result in
559 * tearing down the association.
561 * This means that if we only want to abort associations
562 * in an authenticated way (i.e AUTH+ABORT), then we
563 * can't destroy this association just because the packet
566 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
567 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
569 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
570 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
,
571 asoc
, chunk
->transport
);
574 /* Tag the variable length parameters. Note that we never
575 * convert the parameters in an INIT chunk.
577 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
579 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
581 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
582 SCTP_PEER_INIT(initchunk
));
584 /* Reset init error count upon receipt of INIT-ACK. */
585 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
587 /* 5.1 C) "A" shall stop the T1-init timer and leave
588 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
589 * timer, and enter the COOKIE-ECHOED state.
591 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
592 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
593 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
595 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
596 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
598 /* SCTP-AUTH: genereate the assocition shared keys so that
599 * we can potentially signe the COOKIE-ECHO.
601 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
603 /* 5.1 C) "A" shall then send the State Cookie received in the
604 * INIT ACK chunk in a COOKIE ECHO chunk, ...
606 /* If there is any errors to report, send the ERROR chunk generated
607 * for unknown parameters as well.
609 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
610 SCTP_CHUNK(err_chunk
));
612 return SCTP_DISPOSITION_CONSUME
;
616 * Respond to a normal COOKIE ECHO chunk.
617 * We are the side that is being asked for an association.
619 * Section: 5.1 Normal Establishment of an Association, D
620 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
621 * with a COOKIE ACK chunk after building a TCB and moving to
622 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
623 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
624 * chunk MUST be the first chunk in the packet.
626 * IMPLEMENTATION NOTE: An implementation may choose to send the
627 * Communication Up notification to the SCTP user upon reception
628 * of a valid COOKIE ECHO chunk.
630 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
631 * D) Rules for packet carrying a COOKIE ECHO
633 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
634 * Initial Tag received in the INIT ACK.
636 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
639 * (endpoint, asoc, chunk)
642 * (asoc, reply_msg, msg_up, timers, counters)
644 * The return value is the disposition of the chunk.
646 sctp_disposition_t
sctp_sf_do_5_1D_ce(struct net
*net
,
647 const struct sctp_endpoint
*ep
,
648 const struct sctp_association
*asoc
,
649 const sctp_subtype_t type
, void *arg
,
650 sctp_cmd_seq_t
*commands
)
652 struct sctp_chunk
*chunk
= arg
;
653 struct sctp_association
*new_asoc
;
654 sctp_init_chunk_t
*peer_init
;
655 struct sctp_chunk
*repl
;
656 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
658 struct sctp_chunk
*err_chk_p
;
661 /* If the packet is an OOTB packet which is temporarily on the
662 * control endpoint, respond with an ABORT.
664 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
665 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
666 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
669 /* Make sure that the COOKIE_ECHO chunk has a valid length.
670 * In this case, we check that we have enough for at least a
671 * chunk header. More detailed verification is done
672 * in sctp_unpack_cookie().
674 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
675 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
677 /* If the endpoint is not listening or if the number of associations
678 * on the TCP-style socket exceed the max backlog, respond with an
682 if (!sctp_sstate(sk
, LISTENING
) ||
683 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
684 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
686 /* "Decode" the chunk. We have no optional parameters so we
689 chunk
->subh
.cookie_hdr
=
690 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
691 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
692 sizeof(sctp_chunkhdr_t
)))
695 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
696 * "Z" will reply with a COOKIE ACK chunk after building a TCB
697 * and moving to the ESTABLISHED state.
699 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
703 * If the re-build failed, what is the proper error path
706 * [We should abort the association. --piggy]
709 /* FIXME: Several errors are possible. A bad cookie should
710 * be silently discarded, but think about logging it too.
713 case -SCTP_IERROR_NOMEM
:
716 case -SCTP_IERROR_STALE_COOKIE
:
717 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
719 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
721 case -SCTP_IERROR_BAD_SIG
:
723 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
728 /* Delay state machine commands until later.
730 * Re-build the bind address for the association is done in
731 * the sctp_unpack_cookie() already.
733 /* This is a brand-new association, so these are not yet side
734 * effects--it is safe to run them here.
736 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
738 if (!sctp_process_init(new_asoc
, chunk
,
739 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
740 peer_init
, GFP_ATOMIC
))
743 /* SCTP-AUTH: Now that we've populate required fields in
744 * sctp_process_init, set up the assocaition shared keys as
745 * necessary so that we can potentially authenticate the ACK
747 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
751 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
752 * is supposed to be authenticated and we have to do delayed
753 * authentication. We've just recreated the association using
754 * the information in the cookie and now it's much easier to
755 * do the authentication.
757 if (chunk
->auth_chunk
) {
758 struct sctp_chunk auth
;
761 /* Make sure that we and the peer are AUTH capable */
762 if (!net
->sctp
.auth_enable
|| !new_asoc
->peer
.auth_capable
) {
763 sctp_association_free(new_asoc
);
764 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
767 /* set-up our fake chunk so that we can process it */
768 auth
.skb
= chunk
->auth_chunk
;
769 auth
.asoc
= chunk
->asoc
;
770 auth
.sctp_hdr
= chunk
->sctp_hdr
;
771 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
772 sizeof(sctp_chunkhdr_t
));
773 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
774 auth
.transport
= chunk
->transport
;
776 ret
= sctp_sf_authenticate(net
, ep
, new_asoc
, type
, &auth
);
777 if (ret
!= SCTP_IERROR_NO_ERROR
) {
778 sctp_association_free(new_asoc
);
779 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
783 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
787 /* RFC 2960 5.1 Normal Establishment of an Association
789 * D) IMPLEMENTATION NOTE: An implementation may choose to
790 * send the Communication Up notification to the SCTP user
791 * upon reception of a valid COOKIE ECHO chunk.
793 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
794 new_asoc
->c
.sinit_num_ostreams
,
795 new_asoc
->c
.sinit_max_instreams
,
800 /* Sockets API Draft Section 5.3.1.6
801 * When a peer sends a Adaptation Layer Indication parameter , SCTP
802 * delivers this notification to inform the application that of the
803 * peers requested adaptation layer.
805 if (new_asoc
->peer
.adaptation_ind
) {
806 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
812 /* Add all the state machine commands now since we've created
813 * everything. This way we don't introduce memory corruptions
814 * during side-effect processing and correclty count established
817 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
818 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
819 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
820 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
821 SCTP_INC_STATS(net
, SCTP_MIB_PASSIVEESTABS
);
822 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
824 if (new_asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
825 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
826 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
828 /* This will send the COOKIE ACK */
829 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
831 /* Queue the ASSOC_CHANGE event */
832 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
834 /* Send up the Adaptation Layer Indication event */
836 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
837 SCTP_ULPEVENT(ai_ev
));
839 return SCTP_DISPOSITION_CONSUME
;
842 sctp_ulpevent_free(ev
);
844 sctp_chunk_free(repl
);
846 sctp_association_free(new_asoc
);
848 return SCTP_DISPOSITION_NOMEM
;
852 * Respond to a normal COOKIE ACK chunk.
853 * We are the side that is being asked for an association.
855 * RFC 2960 5.1 Normal Establishment of an Association
857 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
858 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
859 * timer. It may also notify its ULP about the successful
860 * establishment of the association with a Communication Up
861 * notification (see Section 10).
865 * (endpoint, asoc, chunk)
868 * (asoc, reply_msg, msg_up, timers, counters)
870 * The return value is the disposition of the chunk.
872 sctp_disposition_t
sctp_sf_do_5_1E_ca(struct net
*net
,
873 const struct sctp_endpoint
*ep
,
874 const struct sctp_association
*asoc
,
875 const sctp_subtype_t type
, void *arg
,
876 sctp_cmd_seq_t
*commands
)
878 struct sctp_chunk
*chunk
= arg
;
879 struct sctp_ulpevent
*ev
;
881 if (!sctp_vtag_verify(chunk
, asoc
))
882 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
884 /* Verify that the chunk length for the COOKIE-ACK is OK.
885 * If we don't do this, any bundled chunks may be junked.
887 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
888 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
891 /* Reset init error count upon receipt of COOKIE-ACK,
892 * to avoid problems with the managemement of this
893 * counter in stale cookie situations when a transition back
894 * from the COOKIE-ECHOED state to the COOKIE-WAIT
895 * state is performed.
897 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
899 /* RFC 2960 5.1 Normal Establishment of an Association
901 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
902 * from the COOKIE-ECHOED state to the ESTABLISHED state,
903 * stopping the T1-cookie timer.
905 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
906 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
907 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
908 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
909 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
910 SCTP_INC_STATS(net
, SCTP_MIB_ACTIVEESTABS
);
911 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
912 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
913 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
914 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
916 /* It may also notify its ULP about the successful
917 * establishment of the association with a Communication Up
918 * notification (see Section 10).
920 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
921 0, asoc
->c
.sinit_num_ostreams
,
922 asoc
->c
.sinit_max_instreams
,
928 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
930 /* Sockets API Draft Section 5.3.1.6
931 * When a peer sends a Adaptation Layer Indication parameter , SCTP
932 * delivers this notification to inform the application that of the
933 * peers requested adaptation layer.
935 if (asoc
->peer
.adaptation_ind
) {
936 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
940 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
944 return SCTP_DISPOSITION_CONSUME
;
946 return SCTP_DISPOSITION_NOMEM
;
949 /* Generate and sendout a heartbeat packet. */
950 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
951 const struct sctp_association
*asoc
,
952 const sctp_subtype_t type
,
954 sctp_cmd_seq_t
*commands
)
956 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
957 struct sctp_chunk
*reply
;
959 /* Send a heartbeat to our peer. */
960 reply
= sctp_make_heartbeat(asoc
, transport
);
962 return SCTP_DISPOSITION_NOMEM
;
964 /* Set rto_pending indicating that an RTT measurement
965 * is started with this heartbeat chunk.
967 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
968 SCTP_TRANSPORT(transport
));
970 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
971 return SCTP_DISPOSITION_CONSUME
;
974 /* Generate a HEARTBEAT packet on the given transport. */
975 sctp_disposition_t
sctp_sf_sendbeat_8_3(struct net
*net
,
976 const struct sctp_endpoint
*ep
,
977 const struct sctp_association
*asoc
,
978 const sctp_subtype_t type
,
980 sctp_cmd_seq_t
*commands
)
982 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
984 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
985 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
986 SCTP_ERROR(ETIMEDOUT
));
987 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
988 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
989 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
990 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
991 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
992 return SCTP_DISPOSITION_DELETE_TCB
;
996 * The Sender-specific Heartbeat Info field should normally include
997 * information about the sender's current time when this HEARTBEAT
998 * chunk is sent and the destination transport address to which this
999 * HEARTBEAT is sent (see Section 8.3).
1002 if (transport
->param_flags
& SPP_HB_ENABLE
) {
1003 if (SCTP_DISPOSITION_NOMEM
==
1004 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
1006 return SCTP_DISPOSITION_NOMEM
;
1008 /* Set transport error counter and association error counter
1009 * when sending heartbeat.
1011 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
1012 SCTP_TRANSPORT(transport
));
1014 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1015 SCTP_TRANSPORT(transport
));
1016 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1017 SCTP_TRANSPORT(transport
));
1019 return SCTP_DISPOSITION_CONSUME
;
1023 * Process an heartbeat request.
1025 * Section: 8.3 Path Heartbeat
1026 * The receiver of the HEARTBEAT should immediately respond with a
1027 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1028 * from the received HEARTBEAT chunk.
1030 * Verification Tag: 8.5 Verification Tag [Normal verification]
1031 * When receiving an SCTP packet, the endpoint MUST ensure that the
1032 * value in the Verification Tag field of the received SCTP packet
1033 * matches its own Tag. If the received Verification Tag value does not
1034 * match the receiver's own tag value, the receiver shall silently
1035 * discard the packet and shall not process it any further except for
1036 * those cases listed in Section 8.5.1 below.
1039 * (endpoint, asoc, chunk)
1042 * (asoc, reply_msg, msg_up, timers, counters)
1044 * The return value is the disposition of the chunk.
1046 sctp_disposition_t
sctp_sf_beat_8_3(struct net
*net
,
1047 const struct sctp_endpoint
*ep
,
1048 const struct sctp_association
*asoc
,
1049 const sctp_subtype_t type
,
1051 sctp_cmd_seq_t
*commands
)
1053 sctp_paramhdr_t
*param_hdr
;
1054 struct sctp_chunk
*chunk
= arg
;
1055 struct sctp_chunk
*reply
;
1058 if (!sctp_vtag_verify(chunk
, asoc
))
1059 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1061 /* Make sure that the HEARTBEAT chunk has a valid length. */
1062 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1063 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1066 /* 8.3 The receiver of the HEARTBEAT should immediately
1067 * respond with a HEARTBEAT ACK that contains the Heartbeat
1068 * Information field copied from the received HEARTBEAT chunk.
1070 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1071 param_hdr
= (sctp_paramhdr_t
*) chunk
->subh
.hb_hdr
;
1072 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1074 if (ntohs(param_hdr
->length
) > paylen
)
1075 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
1076 param_hdr
, commands
);
1078 if (!pskb_pull(chunk
->skb
, paylen
))
1081 reply
= sctp_make_heartbeat_ack(asoc
, chunk
, param_hdr
, paylen
);
1085 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1086 return SCTP_DISPOSITION_CONSUME
;
1089 return SCTP_DISPOSITION_NOMEM
;
1093 * Process the returning HEARTBEAT ACK.
1095 * Section: 8.3 Path Heartbeat
1096 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1097 * should clear the error counter of the destination transport
1098 * address to which the HEARTBEAT was sent, and mark the destination
1099 * transport address as active if it is not so marked. The endpoint may
1100 * optionally report to the upper layer when an inactive destination
1101 * address is marked as active due to the reception of the latest
1102 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1103 * clear the association overall error count as well (as defined
1106 * The receiver of the HEARTBEAT ACK should also perform an RTT
1107 * measurement for that destination transport address using the time
1108 * value carried in the HEARTBEAT ACK chunk.
1110 * Verification Tag: 8.5 Verification Tag [Normal verification]
1113 * (endpoint, asoc, chunk)
1116 * (asoc, reply_msg, msg_up, timers, counters)
1118 * The return value is the disposition of the chunk.
1120 sctp_disposition_t
sctp_sf_backbeat_8_3(struct net
*net
,
1121 const struct sctp_endpoint
*ep
,
1122 const struct sctp_association
*asoc
,
1123 const sctp_subtype_t type
,
1125 sctp_cmd_seq_t
*commands
)
1127 struct sctp_chunk
*chunk
= arg
;
1128 union sctp_addr from_addr
;
1129 struct sctp_transport
*link
;
1130 sctp_sender_hb_info_t
*hbinfo
;
1131 unsigned long max_interval
;
1133 if (!sctp_vtag_verify(chunk
, asoc
))
1134 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1136 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1137 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
) +
1138 sizeof(sctp_sender_hb_info_t
)))
1139 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1142 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1143 /* Make sure that the length of the parameter is what we expect */
1144 if (ntohs(hbinfo
->param_hdr
.length
) !=
1145 sizeof(sctp_sender_hb_info_t
)) {
1146 return SCTP_DISPOSITION_DISCARD
;
1149 from_addr
= hbinfo
->daddr
;
1150 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1152 /* This should never happen, but lets log it if so. */
1153 if (unlikely(!link
)) {
1154 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1155 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1158 &from_addr
.v6
.sin6_addr
);
1160 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1163 &from_addr
.v4
.sin_addr
.s_addr
);
1165 return SCTP_DISPOSITION_DISCARD
;
1168 /* Validate the 64-bit random nonce. */
1169 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1170 return SCTP_DISPOSITION_DISCARD
;
1172 max_interval
= link
->hbinterval
+ link
->rto
;
1174 /* Check if the timestamp looks valid. */
1175 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1176 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1177 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1178 "for transport:%p\n", __func__
, link
);
1180 return SCTP_DISPOSITION_DISCARD
;
1183 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1184 * the HEARTBEAT should clear the error counter of the
1185 * destination transport address to which the HEARTBEAT was
1186 * sent and mark the destination transport address as active if
1187 * it is not so marked.
1189 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1191 return SCTP_DISPOSITION_CONSUME
;
1194 /* Helper function to send out an abort for the restart
1197 static int sctp_sf_send_restart_abort(struct net
*net
, union sctp_addr
*ssa
,
1198 struct sctp_chunk
*init
,
1199 sctp_cmd_seq_t
*commands
)
1202 struct sctp_packet
*pkt
;
1203 union sctp_addr_param
*addrparm
;
1204 struct sctp_errhdr
*errhdr
;
1205 struct sctp_endpoint
*ep
;
1206 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1207 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1209 /* Build the error on the stack. We are way to malloc crazy
1210 * throughout the code today.
1212 errhdr
= (struct sctp_errhdr
*)buffer
;
1213 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1215 /* Copy into a parm format. */
1216 len
= af
->to_addr_param(ssa
, addrparm
);
1217 len
+= sizeof(sctp_errhdr_t
);
1219 errhdr
->cause
= SCTP_ERROR_RESTART
;
1220 errhdr
->length
= htons(len
);
1222 /* Assign to the control socket. */
1223 ep
= sctp_sk(net
->sctp
.ctl_sock
)->ep
;
1225 /* Association is NULL since this may be a restart attack and we
1226 * want to send back the attacker's vtag.
1228 pkt
= sctp_abort_pkt_new(net
, ep
, NULL
, init
, errhdr
, len
);
1232 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1234 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1236 /* Discard the rest of the inbound packet. */
1237 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1240 /* Even if there is no memory, treat as a failure so
1241 * the packet will get dropped.
1246 static bool list_has_sctp_addr(const struct list_head
*list
,
1247 union sctp_addr
*ipaddr
)
1249 struct sctp_transport
*addr
;
1251 list_for_each_entry(addr
, list
, transports
) {
1252 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1258 /* A restart is occurring, check to make sure no new addresses
1259 * are being added as we may be under a takeover attack.
1261 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1262 const struct sctp_association
*asoc
,
1263 struct sctp_chunk
*init
,
1264 sctp_cmd_seq_t
*commands
)
1266 struct net
*net
= sock_net(new_asoc
->base
.sk
);
1267 struct sctp_transport
*new_addr
;
1270 /* Implementor's Guide - Section 5.2.2
1272 * Before responding the endpoint MUST check to see if the
1273 * unexpected INIT adds new addresses to the association. If new
1274 * addresses are added to the association, the endpoint MUST respond
1278 /* Search through all current addresses and make sure
1279 * we aren't adding any new ones.
1281 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1283 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1284 &new_addr
->ipaddr
)) {
1285 sctp_sf_send_restart_abort(net
, &new_addr
->ipaddr
, init
,
1292 /* Return success if all addresses were found. */
1296 /* Populate the verification/tie tags based on overlapping INIT
1299 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1301 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1302 const struct sctp_association
*asoc
)
1304 switch (asoc
->state
) {
1306 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1308 case SCTP_STATE_COOKIE_WAIT
:
1309 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1310 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1311 new_asoc
->c
.peer_ttag
= 0;
1314 case SCTP_STATE_COOKIE_ECHOED
:
1315 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1316 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1317 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1320 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1321 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1324 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1325 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1329 /* Other parameters for the endpoint SHOULD be copied from the
1330 * existing parameters of the association (e.g. number of
1331 * outbound streams) into the INIT ACK and cookie.
1333 new_asoc
->rwnd
= asoc
->rwnd
;
1334 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1335 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1336 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1340 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1343 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1345 * Returns value representing action to be taken. These action values
1346 * correspond to Action/Description values in RFC 2960, Table 2.
1348 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1349 const struct sctp_association
*asoc
)
1351 /* In this case, the peer may have restarted. */
1352 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1353 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1354 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1355 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1358 /* Collision case B. */
1359 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1360 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1361 (0 == asoc
->c
.peer_vtag
))) {
1365 /* Collision case D. */
1366 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1367 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1370 /* Collision case C. */
1371 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1372 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1373 (0 == new_asoc
->c
.my_ttag
) &&
1374 (0 == new_asoc
->c
.peer_ttag
))
1377 /* No match to any of the special cases; discard this packet. */
1381 /* Common helper routine for both duplicate and simulataneous INIT
1384 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1386 const struct sctp_endpoint
*ep
,
1387 const struct sctp_association
*asoc
,
1388 const sctp_subtype_t type
,
1389 void *arg
, sctp_cmd_seq_t
*commands
)
1391 sctp_disposition_t retval
;
1392 struct sctp_chunk
*chunk
= arg
;
1393 struct sctp_chunk
*repl
;
1394 struct sctp_association
*new_asoc
;
1395 struct sctp_chunk
*err_chunk
;
1396 struct sctp_packet
*packet
;
1397 sctp_unrecognized_param_t
*unk_param
;
1401 * An endpoint MUST NOT bundle INIT, INIT ACK or
1402 * SHUTDOWN COMPLETE with any other chunks.
1405 * Furthermore, we require that the receiver of an INIT chunk MUST
1406 * enforce these rules by silently discarding an arriving packet
1407 * with an INIT chunk that is bundled with other chunks.
1409 if (!chunk
->singleton
)
1410 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1412 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1415 if (chunk
->sctp_hdr
->vtag
!= 0)
1416 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
1418 /* Make sure that the INIT chunk has a valid length.
1419 * In this case, we generate a protocol violation since we have
1420 * an association established.
1422 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1423 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1425 /* Grab the INIT header. */
1426 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1428 /* Tag the variable length parameters. */
1429 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1431 /* Verify the INIT chunk before processing it. */
1433 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
1434 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1436 /* This chunk contains fatal error. It is to be discarded.
1437 * Send an ABORT, with causes if there is any.
1440 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
1441 (__u8
*)(err_chunk
->chunk_hdr
) +
1442 sizeof(sctp_chunkhdr_t
),
1443 ntohs(err_chunk
->chunk_hdr
->length
) -
1444 sizeof(sctp_chunkhdr_t
));
1447 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1448 SCTP_PACKET(packet
));
1449 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1450 retval
= SCTP_DISPOSITION_CONSUME
;
1452 retval
= SCTP_DISPOSITION_NOMEM
;
1456 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
1462 * Other parameters for the endpoint SHOULD be copied from the
1463 * existing parameters of the association (e.g. number of
1464 * outbound streams) into the INIT ACK and cookie.
1465 * FIXME: We are copying parameters from the endpoint not the
1468 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1472 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1473 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1476 /* In the outbound INIT ACK the endpoint MUST copy its current
1477 * Verification Tag and Peers Verification tag into a reserved
1478 * place (local tie-tag and per tie-tag) within the state cookie.
1480 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
1481 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1485 /* Make sure no new addresses are being added during the
1486 * restart. Do not do this check for COOKIE-WAIT state,
1487 * since there are no peer addresses to check against.
1488 * Upon return an ABORT will have been sent if needed.
1490 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1491 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1493 retval
= SCTP_DISPOSITION_CONSUME
;
1498 sctp_tietags_populate(new_asoc
, asoc
);
1500 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1502 /* If there are errors need to be reported for unknown parameters,
1503 * make sure to reserve enough room in the INIT ACK for them.
1507 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1508 sizeof(sctp_chunkhdr_t
);
1511 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1515 /* If there are errors need to be reported for unknown parameters,
1516 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1520 /* Get the "Unrecognized parameter" parameter(s) out of the
1521 * ERROR chunk generated by sctp_verify_init(). Since the
1522 * error cause code for "unknown parameter" and the
1523 * "Unrecognized parameter" type is the same, we can
1524 * construct the parameters in INIT ACK by copying the
1525 * ERROR causes over.
1527 unk_param
= (sctp_unrecognized_param_t
*)
1528 ((__u8
*)(err_chunk
->chunk_hdr
) +
1529 sizeof(sctp_chunkhdr_t
));
1530 /* Replace the cause code with the "Unrecognized parameter"
1533 sctp_addto_chunk(repl
, len
, unk_param
);
1536 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1537 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1540 * Note: After sending out INIT ACK with the State Cookie parameter,
1541 * "Z" MUST NOT allocate any resources for this new association.
1542 * Otherwise, "Z" will be vulnerable to resource attacks.
1544 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1545 retval
= SCTP_DISPOSITION_CONSUME
;
1550 retval
= SCTP_DISPOSITION_NOMEM
;
1553 sctp_association_free(new_asoc
);
1556 sctp_chunk_free(err_chunk
);
1561 * Handle simultaneous INIT.
1562 * This means we started an INIT and then we got an INIT request from
1565 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1566 * This usually indicates an initialization collision, i.e., each
1567 * endpoint is attempting, at about the same time, to establish an
1568 * association with the other endpoint.
1570 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1571 * endpoint MUST respond with an INIT ACK using the same parameters it
1572 * sent in its original INIT chunk (including its Verification Tag,
1573 * unchanged). These original parameters are combined with those from the
1574 * newly received INIT chunk. The endpoint shall also generate a State
1575 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1576 * INIT to calculate the State Cookie.
1578 * After that, the endpoint MUST NOT change its state, the T1-init
1579 * timer shall be left running and the corresponding TCB MUST NOT be
1580 * destroyed. The normal procedures for handling State Cookies when
1581 * a TCB exists will resolve the duplicate INITs to a single association.
1583 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1584 * its Tie-Tags with the Tag information of itself and its peer (see
1585 * section 5.2.2 for a description of the Tie-Tags).
1587 * Verification Tag: Not explicit, but an INIT can not have a valid
1588 * verification tag, so we skip the check.
1591 * (endpoint, asoc, chunk)
1594 * (asoc, reply_msg, msg_up, timers, counters)
1596 * The return value is the disposition of the chunk.
1598 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(struct net
*net
,
1599 const struct sctp_endpoint
*ep
,
1600 const struct sctp_association
*asoc
,
1601 const sctp_subtype_t type
,
1603 sctp_cmd_seq_t
*commands
)
1605 /* Call helper to do the real work for both simulataneous and
1606 * duplicate INIT chunk handling.
1608 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1612 * Handle duplicated INIT messages. These are usually delayed
1615 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1616 * COOKIE-ECHOED and COOKIE-WAIT
1618 * Unless otherwise stated, upon reception of an unexpected INIT for
1619 * this association, the endpoint shall generate an INIT ACK with a
1620 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1621 * current Verification Tag and peer's Verification Tag into a reserved
1622 * place within the state cookie. We shall refer to these locations as
1623 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1624 * containing this INIT ACK MUST carry a Verification Tag value equal to
1625 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1626 * MUST contain a new Initiation Tag (randomly generated see Section
1627 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1628 * existing parameters of the association (e.g. number of outbound
1629 * streams) into the INIT ACK and cookie.
1631 * After sending out the INIT ACK, the endpoint shall take no further
1632 * actions, i.e., the existing association, including its current state,
1633 * and the corresponding TCB MUST NOT be changed.
1635 * Note: Only when a TCB exists and the association is not in a COOKIE-
1636 * WAIT state are the Tie-Tags populated. For a normal association INIT
1637 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1638 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1639 * State Cookie are populated as specified in section 5.2.1.
1641 * Verification Tag: Not specified, but an INIT has no way of knowing
1642 * what the verification tag could be, so we ignore it.
1645 * (endpoint, asoc, chunk)
1648 * (asoc, reply_msg, msg_up, timers, counters)
1650 * The return value is the disposition of the chunk.
1652 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(struct net
*net
,
1653 const struct sctp_endpoint
*ep
,
1654 const struct sctp_association
*asoc
,
1655 const sctp_subtype_t type
,
1657 sctp_cmd_seq_t
*commands
)
1659 /* Call helper to do the real work for both simulataneous and
1660 * duplicate INIT chunk handling.
1662 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1667 * Unexpected INIT-ACK handler.
1670 * If an INIT ACK received by an endpoint in any state other than the
1671 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1672 * An unexpected INIT ACK usually indicates the processing of an old or
1673 * duplicated INIT chunk.
1675 sctp_disposition_t
sctp_sf_do_5_2_3_initack(struct net
*net
,
1676 const struct sctp_endpoint
*ep
,
1677 const struct sctp_association
*asoc
,
1678 const sctp_subtype_t type
,
1679 void *arg
, sctp_cmd_seq_t
*commands
)
1681 /* Per the above section, we'll discard the chunk if we have an
1682 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1684 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
)
1685 return sctp_sf_ootb(net
, ep
, asoc
, type
, arg
, commands
);
1687 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
1690 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1693 * A) In this case, the peer may have restarted.
1695 static sctp_disposition_t
sctp_sf_do_dupcook_a(struct net
*net
,
1696 const struct sctp_endpoint
*ep
,
1697 const struct sctp_association
*asoc
,
1698 struct sctp_chunk
*chunk
,
1699 sctp_cmd_seq_t
*commands
,
1700 struct sctp_association
*new_asoc
)
1702 sctp_init_chunk_t
*peer_init
;
1703 struct sctp_ulpevent
*ev
;
1704 struct sctp_chunk
*repl
;
1705 struct sctp_chunk
*err
;
1706 sctp_disposition_t disposition
;
1708 /* new_asoc is a brand-new association, so these are not yet
1709 * side effects--it is safe to run them here.
1711 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1713 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1717 /* Make sure no new addresses are being added during the
1718 * restart. Though this is a pretty complicated attack
1719 * since you'd have to get inside the cookie.
1721 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1722 return SCTP_DISPOSITION_CONSUME
;
1725 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1726 * the peer has restarted (Action A), it MUST NOT setup a new
1727 * association but instead resend the SHUTDOWN ACK and send an ERROR
1728 * chunk with a "Cookie Received while Shutting Down" error cause to
1731 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1732 disposition
= sctp_sf_do_9_2_reshutack(net
, ep
, asoc
,
1733 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1735 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1738 err
= sctp_make_op_error(asoc
, chunk
,
1739 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1742 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1745 return SCTP_DISPOSITION_CONSUME
;
1748 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1749 * data. Consider the optional choice of resending of this data.
1751 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
1752 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1753 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
1754 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1756 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1757 * and ASCONF-ACK cache.
1759 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1760 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
1761 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_ASCONF_QUEUE
, SCTP_NULL());
1763 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1767 /* Report association restart to upper layer. */
1768 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1769 new_asoc
->c
.sinit_num_ostreams
,
1770 new_asoc
->c
.sinit_max_instreams
,
1775 /* Update the content of current association. */
1776 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1777 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1778 if (sctp_state(asoc
, SHUTDOWN_PENDING
) &&
1779 (sctp_sstate(asoc
->base
.sk
, CLOSING
) ||
1780 sock_flag(asoc
->base
.sk
, SOCK_DEAD
))) {
1781 /* if were currently in SHUTDOWN_PENDING, but the socket
1782 * has been closed by user, don't transition to ESTABLISHED.
1783 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1785 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1786 return sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
,
1787 SCTP_ST_CHUNK(0), NULL
,
1790 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1791 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1792 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1794 return SCTP_DISPOSITION_CONSUME
;
1797 sctp_chunk_free(repl
);
1799 return SCTP_DISPOSITION_NOMEM
;
1802 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1805 * B) In this case, both sides may be attempting to start an association
1806 * at about the same time but the peer endpoint started its INIT
1807 * after responding to the local endpoint's INIT
1809 /* This case represents an initialization collision. */
1810 static sctp_disposition_t
sctp_sf_do_dupcook_b(struct net
*net
,
1811 const struct sctp_endpoint
*ep
,
1812 const struct sctp_association
*asoc
,
1813 struct sctp_chunk
*chunk
,
1814 sctp_cmd_seq_t
*commands
,
1815 struct sctp_association
*new_asoc
)
1817 sctp_init_chunk_t
*peer_init
;
1818 struct sctp_chunk
*repl
;
1820 /* new_asoc is a brand-new association, so these are not yet
1821 * side effects--it is safe to run them here.
1823 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1824 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1828 /* Update the content of current association. */
1829 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1830 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1831 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1832 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1833 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1835 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1839 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1841 /* RFC 2960 5.1 Normal Establishment of an Association
1843 * D) IMPLEMENTATION NOTE: An implementation may choose to
1844 * send the Communication Up notification to the SCTP user
1845 * upon reception of a valid COOKIE ECHO chunk.
1847 * Sadly, this needs to be implemented as a side-effect, because
1848 * we are not guaranteed to have set the association id of the real
1849 * association and so these notifications need to be delayed until
1850 * the association id is allocated.
1853 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1855 /* Sockets API Draft Section 5.3.1.6
1856 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1857 * delivers this notification to inform the application that of the
1858 * peers requested adaptation layer.
1860 * This also needs to be done as a side effect for the same reason as
1863 if (asoc
->peer
.adaptation_ind
)
1864 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1866 return SCTP_DISPOSITION_CONSUME
;
1869 return SCTP_DISPOSITION_NOMEM
;
1872 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1875 * C) In this case, the local endpoint's cookie has arrived late.
1876 * Before it arrived, the local endpoint sent an INIT and received an
1877 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1878 * but a new tag of its own.
1880 /* This case represents an initialization collision. */
1881 static sctp_disposition_t
sctp_sf_do_dupcook_c(struct net
*net
,
1882 const struct sctp_endpoint
*ep
,
1883 const struct sctp_association
*asoc
,
1884 struct sctp_chunk
*chunk
,
1885 sctp_cmd_seq_t
*commands
,
1886 struct sctp_association
*new_asoc
)
1888 /* The cookie should be silently discarded.
1889 * The endpoint SHOULD NOT change states and should leave
1890 * any timers running.
1892 return SCTP_DISPOSITION_DISCARD
;
1895 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1899 * D) When both local and remote tags match the endpoint should always
1900 * enter the ESTABLISHED state, if it has not already done so.
1902 /* This case represents an initialization collision. */
1903 static sctp_disposition_t
sctp_sf_do_dupcook_d(struct net
*net
,
1904 const struct sctp_endpoint
*ep
,
1905 const struct sctp_association
*asoc
,
1906 struct sctp_chunk
*chunk
,
1907 sctp_cmd_seq_t
*commands
,
1908 struct sctp_association
*new_asoc
)
1910 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1911 struct sctp_chunk
*repl
;
1913 /* Clarification from Implementor's Guide:
1914 * D) When both local and remote tags match the endpoint should
1915 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1916 * It should stop any cookie timer that may be running and send
1920 /* Don't accidentally move back into established state. */
1921 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1922 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1923 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1924 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1925 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1926 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1927 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1930 /* RFC 2960 5.1 Normal Establishment of an Association
1932 * D) IMPLEMENTATION NOTE: An implementation may choose
1933 * to send the Communication Up notification to the
1934 * SCTP user upon reception of a valid COOKIE
1937 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1939 asoc
->c
.sinit_num_ostreams
,
1940 asoc
->c
.sinit_max_instreams
,
1945 /* Sockets API Draft Section 5.3.1.6
1946 * When a peer sends a Adaptation Layer Indication parameter,
1947 * SCTP delivers this notification to inform the application
1948 * that of the peers requested adaptation layer.
1950 if (asoc
->peer
.adaptation_ind
) {
1951 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1959 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1963 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1966 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1969 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1970 SCTP_ULPEVENT(ai_ev
));
1972 return SCTP_DISPOSITION_CONSUME
;
1976 sctp_ulpevent_free(ai_ev
);
1978 sctp_ulpevent_free(ev
);
1979 return SCTP_DISPOSITION_NOMEM
;
1983 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1984 * chunk was retransmitted and then delayed in the network.
1986 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1988 * Verification Tag: None. Do cookie validation.
1991 * (endpoint, asoc, chunk)
1994 * (asoc, reply_msg, msg_up, timers, counters)
1996 * The return value is the disposition of the chunk.
1998 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(struct net
*net
,
1999 const struct sctp_endpoint
*ep
,
2000 const struct sctp_association
*asoc
,
2001 const sctp_subtype_t type
,
2003 sctp_cmd_seq_t
*commands
)
2005 sctp_disposition_t retval
;
2006 struct sctp_chunk
*chunk
= arg
;
2007 struct sctp_association
*new_asoc
;
2010 struct sctp_chunk
*err_chk_p
;
2012 /* Make sure that the chunk has a valid length from the protocol
2013 * perspective. In this case check to make sure we have at least
2014 * enough for the chunk header. Cookie length verification is
2017 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2018 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2021 /* "Decode" the chunk. We have no optional parameters so we
2022 * are in good shape.
2024 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
2025 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
2026 sizeof(sctp_chunkhdr_t
)))
2029 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2030 * of a duplicate COOKIE ECHO match the Verification Tags of the
2031 * current association, consider the State Cookie valid even if
2032 * the lifespan is exceeded.
2034 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
2038 * If the re-build failed, what is the proper error path
2041 * [We should abort the association. --piggy]
2044 /* FIXME: Several errors are possible. A bad cookie should
2045 * be silently discarded, but think about logging it too.
2048 case -SCTP_IERROR_NOMEM
:
2051 case -SCTP_IERROR_STALE_COOKIE
:
2052 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
2054 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2055 case -SCTP_IERROR_BAD_SIG
:
2057 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2061 /* Compare the tie_tag in cookie with the verification tag of
2062 * current association.
2064 action
= sctp_tietags_compare(new_asoc
, asoc
);
2067 case 'A': /* Association restart. */
2068 retval
= sctp_sf_do_dupcook_a(net
, ep
, asoc
, chunk
, commands
,
2072 case 'B': /* Collision case B. */
2073 retval
= sctp_sf_do_dupcook_b(net
, ep
, asoc
, chunk
, commands
,
2077 case 'C': /* Collision case C. */
2078 retval
= sctp_sf_do_dupcook_c(net
, ep
, asoc
, chunk
, commands
,
2082 case 'D': /* Collision case D. */
2083 retval
= sctp_sf_do_dupcook_d(net
, ep
, asoc
, chunk
, commands
,
2087 default: /* Discard packet for all others. */
2088 retval
= sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2092 /* Delete the tempory new association. */
2093 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
, SCTP_ASOC(new_asoc
));
2094 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2096 /* Restore association pointer to provide SCTP command interpeter
2097 * with a valid context in case it needs to manipulate
2099 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
,
2100 SCTP_ASOC((struct sctp_association
*)asoc
));
2105 return SCTP_DISPOSITION_NOMEM
;
2109 * Process an ABORT. (SHUTDOWN-PENDING state)
2111 * See sctp_sf_do_9_1_abort().
2113 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2115 const struct sctp_endpoint
*ep
,
2116 const struct sctp_association
*asoc
,
2117 const sctp_subtype_t type
,
2119 sctp_cmd_seq_t
*commands
)
2121 struct sctp_chunk
*chunk
= arg
;
2123 if (!sctp_vtag_verify_either(chunk
, asoc
))
2124 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2126 /* Make sure that the ABORT chunk has a valid length.
2127 * Since this is an ABORT chunk, we have to discard it
2128 * because of the following text:
2129 * RFC 2960, Section 3.3.7
2130 * If an endpoint receives an ABORT with a format error or for an
2131 * association that doesn't exist, it MUST silently discard it.
2132 * Because the length is "invalid", we can't really discard just
2133 * as we do not know its true length. So, to be safe, discard the
2136 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2137 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2139 /* ADD-IP: Special case for ABORT chunks
2140 * F4) One special consideration is that ABORT Chunks arriving
2141 * destined to the IP address being deleted MUST be
2142 * ignored (see Section 5.3.1 for further details).
2144 if (SCTP_ADDR_DEL
==
2145 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2146 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2148 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2152 * Process an ABORT. (SHUTDOWN-SENT state)
2154 * See sctp_sf_do_9_1_abort().
2156 sctp_disposition_t
sctp_sf_shutdown_sent_abort(struct net
*net
,
2157 const struct sctp_endpoint
*ep
,
2158 const struct sctp_association
*asoc
,
2159 const sctp_subtype_t type
,
2161 sctp_cmd_seq_t
*commands
)
2163 struct sctp_chunk
*chunk
= arg
;
2165 if (!sctp_vtag_verify_either(chunk
, asoc
))
2166 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2168 /* Make sure that the ABORT chunk has a valid length.
2169 * Since this is an ABORT chunk, we have to discard it
2170 * because of the following text:
2171 * RFC 2960, Section 3.3.7
2172 * If an endpoint receives an ABORT with a format error or for an
2173 * association that doesn't exist, it MUST silently discard it.
2174 * Because the length is "invalid", we can't really discard just
2175 * as we do not know its true length. So, to be safe, discard the
2178 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2179 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2181 /* ADD-IP: Special case for ABORT chunks
2182 * F4) One special consideration is that ABORT Chunks arriving
2183 * destined to the IP address being deleted MUST be
2184 * ignored (see Section 5.3.1 for further details).
2186 if (SCTP_ADDR_DEL
==
2187 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2188 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2190 /* Stop the T2-shutdown timer. */
2191 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2192 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2194 /* Stop the T5-shutdown guard timer. */
2195 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2196 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2198 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2202 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2204 * See sctp_sf_do_9_1_abort().
2206 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2208 const struct sctp_endpoint
*ep
,
2209 const struct sctp_association
*asoc
,
2210 const sctp_subtype_t type
,
2212 sctp_cmd_seq_t
*commands
)
2214 /* The same T2 timer, so we should be able to use
2215 * common function with the SHUTDOWN-SENT state.
2217 return sctp_sf_shutdown_sent_abort(net
, ep
, asoc
, type
, arg
, commands
);
2221 * Handle an Error received in COOKIE_ECHOED state.
2223 * Only handle the error type of stale COOKIE Error, the other errors will
2227 * (endpoint, asoc, chunk)
2230 * (asoc, reply_msg, msg_up, timers, counters)
2232 * The return value is the disposition of the chunk.
2234 sctp_disposition_t
sctp_sf_cookie_echoed_err(struct net
*net
,
2235 const struct sctp_endpoint
*ep
,
2236 const struct sctp_association
*asoc
,
2237 const sctp_subtype_t type
,
2239 sctp_cmd_seq_t
*commands
)
2241 struct sctp_chunk
*chunk
= arg
;
2244 if (!sctp_vtag_verify(chunk
, asoc
))
2245 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2247 /* Make sure that the ERROR chunk has a valid length.
2248 * The parameter walking depends on this as well.
2250 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2251 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2254 /* Process the error here */
2255 /* FUTURE FIXME: When PR-SCTP related and other optional
2256 * parms are emitted, this will have to change to handle multiple
2259 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2260 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2261 return sctp_sf_do_5_2_6_stale(net
, ep
, asoc
, type
,
2265 /* It is possible to have malformed error causes, and that
2266 * will cause us to end the walk early. However, since
2267 * we are discarding the packet, there should be no adverse
2270 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2274 * Handle a Stale COOKIE Error
2276 * Section: 5.2.6 Handle Stale COOKIE Error
2277 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2278 * one of the following three alternatives.
2280 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2281 * Preservative parameter requesting an extension to the lifetime of
2282 * the State Cookie. When calculating the time extension, an
2283 * implementation SHOULD use the RTT information measured based on the
2284 * previous COOKIE ECHO / ERROR exchange, and should add no more
2285 * than 1 second beyond the measured RTT, due to long State Cookie
2286 * lifetimes making the endpoint more subject to a replay attack.
2288 * Verification Tag: Not explicit, but safe to ignore.
2291 * (endpoint, asoc, chunk)
2294 * (asoc, reply_msg, msg_up, timers, counters)
2296 * The return value is the disposition of the chunk.
2298 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(struct net
*net
,
2299 const struct sctp_endpoint
*ep
,
2300 const struct sctp_association
*asoc
,
2301 const sctp_subtype_t type
,
2303 sctp_cmd_seq_t
*commands
)
2305 struct sctp_chunk
*chunk
= arg
;
2307 sctp_cookie_preserve_param_t bht
;
2309 struct sctp_chunk
*reply
;
2310 struct sctp_bind_addr
*bp
;
2311 int attempts
= asoc
->init_err_counter
+ 1;
2313 if (attempts
> asoc
->max_init_attempts
) {
2314 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2315 SCTP_ERROR(ETIMEDOUT
));
2316 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2317 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2318 return SCTP_DISPOSITION_DELETE_TCB
;
2321 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2323 /* When calculating the time extension, an implementation
2324 * SHOULD use the RTT information measured based on the
2325 * previous COOKIE ECHO / ERROR exchange, and should add no
2326 * more than 1 second beyond the measured RTT, due to long
2327 * State Cookie lifetimes making the endpoint more subject to
2329 * Measure of Staleness's unit is usec. (1/1000000 sec)
2330 * Suggested Cookie Life-span Increment's unit is msec.
2332 * In general, if you use the suggested cookie life, the value
2333 * found in the field of measure of staleness should be doubled
2334 * to give ample time to retransmit the new cookie and thus
2335 * yield a higher probability of success on the reattempt.
2337 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2338 stale
= (stale
* 2) / 1000;
2340 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2341 bht
.param_hdr
.length
= htons(sizeof(bht
));
2342 bht
.lifespan_increment
= htonl(stale
);
2344 /* Build that new INIT chunk. */
2345 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2346 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2350 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2352 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2353 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2355 /* Stop pending T3-rtx and heartbeat timers */
2356 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2357 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2359 /* Delete non-primary peer ip addresses since we are transitioning
2360 * back to the COOKIE-WAIT state
2362 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2364 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2367 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2368 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2370 /* Cast away the const modifier, as we want to just
2371 * rerun it through as a sideffect.
2373 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2375 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2376 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2377 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2378 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2379 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2380 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2382 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2384 return SCTP_DISPOSITION_CONSUME
;
2387 return SCTP_DISPOSITION_NOMEM
;
2394 * After checking the Verification Tag, the receiving endpoint shall
2395 * remove the association from its record, and shall report the
2396 * termination to its upper layer.
2398 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2399 * B) Rules for packet carrying ABORT:
2401 * - The endpoint shall always fill in the Verification Tag field of the
2402 * outbound packet with the destination endpoint's tag value if it
2405 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2406 * MUST follow the procedure described in Section 8.4.
2408 * - The receiver MUST accept the packet if the Verification Tag
2409 * matches either its own tag, OR the tag of its peer. Otherwise, the
2410 * receiver MUST silently discard the packet and take no further
2414 * (endpoint, asoc, chunk)
2417 * (asoc, reply_msg, msg_up, timers, counters)
2419 * The return value is the disposition of the chunk.
2421 sctp_disposition_t
sctp_sf_do_9_1_abort(struct net
*net
,
2422 const struct sctp_endpoint
*ep
,
2423 const struct sctp_association
*asoc
,
2424 const sctp_subtype_t type
,
2426 sctp_cmd_seq_t
*commands
)
2428 struct sctp_chunk
*chunk
= arg
;
2430 if (!sctp_vtag_verify_either(chunk
, asoc
))
2431 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2433 /* Make sure that the ABORT chunk has a valid length.
2434 * Since this is an ABORT chunk, we have to discard it
2435 * because of the following text:
2436 * RFC 2960, Section 3.3.7
2437 * If an endpoint receives an ABORT with a format error or for an
2438 * association that doesn't exist, it MUST silently discard it.
2439 * Because the length is "invalid", we can't really discard just
2440 * as we do not know its true length. So, to be safe, discard the
2443 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2444 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2446 /* ADD-IP: Special case for ABORT chunks
2447 * F4) One special consideration is that ABORT Chunks arriving
2448 * destined to the IP address being deleted MUST be
2449 * ignored (see Section 5.3.1 for further details).
2451 if (SCTP_ADDR_DEL
==
2452 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2453 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2455 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2458 static sctp_disposition_t
__sctp_sf_do_9_1_abort(struct net
*net
,
2459 const struct sctp_endpoint
*ep
,
2460 const struct sctp_association
*asoc
,
2461 const sctp_subtype_t type
,
2463 sctp_cmd_seq_t
*commands
)
2465 struct sctp_chunk
*chunk
= arg
;
2467 __be16 error
= SCTP_ERROR_NO_ERROR
;
2469 /* See if we have an error cause code in the chunk. */
2470 len
= ntohs(chunk
->chunk_hdr
->length
);
2471 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2474 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2475 if ((void *)err
!= (void *)chunk
->chunk_end
)
2476 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2478 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2481 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2482 /* ASSOC_FAILED will DELETE_TCB. */
2483 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2484 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2485 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
2487 return SCTP_DISPOSITION_ABORT
;
2491 * Process an ABORT. (COOKIE-WAIT state)
2493 * See sctp_sf_do_9_1_abort() above.
2495 sctp_disposition_t
sctp_sf_cookie_wait_abort(struct net
*net
,
2496 const struct sctp_endpoint
*ep
,
2497 const struct sctp_association
*asoc
,
2498 const sctp_subtype_t type
,
2500 sctp_cmd_seq_t
*commands
)
2502 struct sctp_chunk
*chunk
= arg
;
2504 __be16 error
= SCTP_ERROR_NO_ERROR
;
2506 if (!sctp_vtag_verify_either(chunk
, asoc
))
2507 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2509 /* Make sure that the ABORT chunk has a valid length.
2510 * Since this is an ABORT chunk, we have to discard it
2511 * because of the following text:
2512 * RFC 2960, Section 3.3.7
2513 * If an endpoint receives an ABORT with a format error or for an
2514 * association that doesn't exist, it MUST silently discard it.
2515 * Because the length is "invalid", we can't really discard just
2516 * as we do not know its true length. So, to be safe, discard the
2519 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2520 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2522 /* See if we have an error cause code in the chunk. */
2523 len
= ntohs(chunk
->chunk_hdr
->length
);
2524 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2525 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2527 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
, asoc
,
2532 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2534 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(struct net
*net
,
2535 const struct sctp_endpoint
*ep
,
2536 const struct sctp_association
*asoc
,
2537 const sctp_subtype_t type
,
2539 sctp_cmd_seq_t
*commands
)
2541 return sctp_stop_t1_and_abort(net
, commands
, SCTP_ERROR_NO_ERROR
,
2543 (struct sctp_transport
*)arg
);
2547 * Process an ABORT. (COOKIE-ECHOED state)
2549 sctp_disposition_t
sctp_sf_cookie_echoed_abort(struct net
*net
,
2550 const struct sctp_endpoint
*ep
,
2551 const struct sctp_association
*asoc
,
2552 const sctp_subtype_t type
,
2554 sctp_cmd_seq_t
*commands
)
2556 /* There is a single T1 timer, so we should be able to use
2557 * common function with the COOKIE-WAIT state.
2559 return sctp_sf_cookie_wait_abort(net
, ep
, asoc
, type
, arg
, commands
);
2563 * Stop T1 timer and abort association with "INIT failed".
2565 * This is common code called by several sctp_sf_*_abort() functions above.
2567 static sctp_disposition_t
sctp_stop_t1_and_abort(struct net
*net
,
2568 sctp_cmd_seq_t
*commands
,
2569 __be16 error
, int sk_err
,
2570 const struct sctp_association
*asoc
,
2571 struct sctp_transport
*transport
)
2573 pr_debug("%s: ABORT received (INIT)\n", __func__
);
2575 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2576 SCTP_STATE(SCTP_STATE_CLOSED
));
2577 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2578 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2579 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2580 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2581 /* CMD_INIT_FAILED will DELETE_TCB. */
2582 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2585 return SCTP_DISPOSITION_ABORT
;
2589 * sctp_sf_do_9_2_shut
2592 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2593 * - enter the SHUTDOWN-RECEIVED state,
2595 * - stop accepting new data from its SCTP user
2597 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2598 * that all its outstanding DATA chunks have been received by the
2601 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2602 * send a SHUTDOWN in response to a ULP request. And should discard
2603 * subsequent SHUTDOWN chunks.
2605 * If there are still outstanding DATA chunks left, the SHUTDOWN
2606 * receiver shall continue to follow normal data transmission
2607 * procedures defined in Section 6 until all outstanding DATA chunks
2608 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2609 * new data from its SCTP user.
2611 * Verification Tag: 8.5 Verification Tag [Normal verification]
2614 * (endpoint, asoc, chunk)
2617 * (asoc, reply_msg, msg_up, timers, counters)
2619 * The return value is the disposition of the chunk.
2621 sctp_disposition_t
sctp_sf_do_9_2_shutdown(struct net
*net
,
2622 const struct sctp_endpoint
*ep
,
2623 const struct sctp_association
*asoc
,
2624 const sctp_subtype_t type
,
2626 sctp_cmd_seq_t
*commands
)
2628 struct sctp_chunk
*chunk
= arg
;
2629 sctp_shutdownhdr_t
*sdh
;
2630 sctp_disposition_t disposition
;
2631 struct sctp_ulpevent
*ev
;
2634 if (!sctp_vtag_verify(chunk
, asoc
))
2635 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2637 /* Make sure that the SHUTDOWN chunk has a valid length. */
2638 if (!sctp_chunk_length_valid(chunk
,
2639 sizeof(struct sctp_shutdown_chunk_t
)))
2640 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2643 /* Convert the elaborate header. */
2644 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2645 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2646 chunk
->subh
.shutdown_hdr
= sdh
;
2647 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2649 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2650 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2651 asoc
->ctsn_ack_point
);
2653 return SCTP_DISPOSITION_DISCARD
;
2656 /* If Cumulative TSN Ack beyond the max tsn currently
2657 * send, terminating the association and respond to the
2658 * sender with an ABORT.
2660 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2661 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2663 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2664 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2665 * inform the application that it should cease sending data.
2667 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2669 disposition
= SCTP_DISPOSITION_NOMEM
;
2672 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2674 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2675 * - enter the SHUTDOWN-RECEIVED state,
2676 * - stop accepting new data from its SCTP user
2678 * [This is implicit in the new state.]
2680 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2681 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2682 disposition
= SCTP_DISPOSITION_CONSUME
;
2684 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2685 disposition
= sctp_sf_do_9_2_shutdown_ack(net
, ep
, asoc
, type
,
2689 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2692 /* - verify, by checking the Cumulative TSN Ack field of the
2693 * chunk, that all its outstanding DATA chunks have been
2694 * received by the SHUTDOWN sender.
2696 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2697 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2704 * sctp_sf_do_9_2_shut_ctsn
2706 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2707 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2708 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2709 * MUST be processed.
2711 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(struct net
*net
,
2712 const struct sctp_endpoint
*ep
,
2713 const struct sctp_association
*asoc
,
2714 const sctp_subtype_t type
,
2716 sctp_cmd_seq_t
*commands
)
2718 struct sctp_chunk
*chunk
= arg
;
2719 sctp_shutdownhdr_t
*sdh
;
2722 if (!sctp_vtag_verify(chunk
, asoc
))
2723 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2725 /* Make sure that the SHUTDOWN chunk has a valid length. */
2726 if (!sctp_chunk_length_valid(chunk
,
2727 sizeof(struct sctp_shutdown_chunk_t
)))
2728 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2731 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2732 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2734 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2735 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2736 asoc
->ctsn_ack_point
);
2738 return SCTP_DISPOSITION_DISCARD
;
2741 /* If Cumulative TSN Ack beyond the max tsn currently
2742 * send, terminating the association and respond to the
2743 * sender with an ABORT.
2745 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2746 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2748 /* verify, by checking the Cumulative TSN Ack field of the
2749 * chunk, that all its outstanding DATA chunks have been
2750 * received by the SHUTDOWN sender.
2752 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2753 SCTP_BE32(sdh
->cum_tsn_ack
));
2755 return SCTP_DISPOSITION_CONSUME
;
2759 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2760 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2761 * transport addresses (either in the IP addresses or in the INIT chunk)
2762 * that belong to this association, it should discard the INIT chunk and
2763 * retransmit the SHUTDOWN ACK chunk.
2765 sctp_disposition_t
sctp_sf_do_9_2_reshutack(struct net
*net
,
2766 const struct sctp_endpoint
*ep
,
2767 const struct sctp_association
*asoc
,
2768 const sctp_subtype_t type
,
2770 sctp_cmd_seq_t
*commands
)
2772 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2773 struct sctp_chunk
*reply
;
2775 /* Make sure that the chunk has a valid length */
2776 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2777 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2780 /* Since we are not going to really process this INIT, there
2781 * is no point in verifying chunk boundries. Just generate
2784 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2788 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2789 * the T2-SHUTDOWN timer.
2791 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2793 /* and restart the T2-shutdown timer. */
2794 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2795 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2797 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2799 return SCTP_DISPOSITION_CONSUME
;
2801 return SCTP_DISPOSITION_NOMEM
;
2805 * sctp_sf_do_ecn_cwr
2807 * Section: Appendix A: Explicit Congestion Notification
2811 * RFC 2481 details a specific bit for a sender to send in the header of
2812 * its next outbound TCP segment to indicate to its peer that it has
2813 * reduced its congestion window. This is termed the CWR bit. For
2814 * SCTP the same indication is made by including the CWR chunk.
2815 * This chunk contains one data element, i.e. the TSN number that
2816 * was sent in the ECNE chunk. This element represents the lowest
2817 * TSN number in the datagram that was originally marked with the
2820 * Verification Tag: 8.5 Verification Tag [Normal verification]
2822 * (endpoint, asoc, chunk)
2825 * (asoc, reply_msg, msg_up, timers, counters)
2827 * The return value is the disposition of the chunk.
2829 sctp_disposition_t
sctp_sf_do_ecn_cwr(struct net
*net
,
2830 const struct sctp_endpoint
*ep
,
2831 const struct sctp_association
*asoc
,
2832 const sctp_subtype_t type
,
2834 sctp_cmd_seq_t
*commands
)
2837 struct sctp_chunk
*chunk
= arg
;
2840 if (!sctp_vtag_verify(chunk
, asoc
))
2841 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2843 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2844 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2847 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2848 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2850 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2852 /* Does this CWR ack the last sent congestion notification? */
2853 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2854 /* Stop sending ECNE. */
2855 sctp_add_cmd_sf(commands
,
2857 SCTP_U32(lowest_tsn
));
2859 return SCTP_DISPOSITION_CONSUME
;
2865 * Section: Appendix A: Explicit Congestion Notification
2869 * RFC 2481 details a specific bit for a receiver to send back in its
2870 * TCP acknowledgements to notify the sender of the Congestion
2871 * Experienced (CE) bit having arrived from the network. For SCTP this
2872 * same indication is made by including the ECNE chunk. This chunk
2873 * contains one data element, i.e. the lowest TSN associated with the IP
2874 * datagram marked with the CE bit.....
2876 * Verification Tag: 8.5 Verification Tag [Normal verification]
2878 * (endpoint, asoc, chunk)
2881 * (asoc, reply_msg, msg_up, timers, counters)
2883 * The return value is the disposition of the chunk.
2885 sctp_disposition_t
sctp_sf_do_ecne(struct net
*net
,
2886 const struct sctp_endpoint
*ep
,
2887 const struct sctp_association
*asoc
,
2888 const sctp_subtype_t type
,
2890 sctp_cmd_seq_t
*commands
)
2892 sctp_ecnehdr_t
*ecne
;
2893 struct sctp_chunk
*chunk
= arg
;
2895 if (!sctp_vtag_verify(chunk
, asoc
))
2896 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2898 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2899 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2902 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2903 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2905 /* If this is a newer ECNE than the last CWR packet we sent out */
2906 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2907 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2909 return SCTP_DISPOSITION_CONSUME
;
2913 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2915 * The SCTP endpoint MUST always acknowledge the reception of each valid
2918 * The guidelines on delayed acknowledgement algorithm specified in
2919 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2920 * acknowledgement SHOULD be generated for at least every second packet
2921 * (not every second DATA chunk) received, and SHOULD be generated within
2922 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2923 * situations it may be beneficial for an SCTP transmitter to be more
2924 * conservative than the algorithms detailed in this document allow.
2925 * However, an SCTP transmitter MUST NOT be more aggressive than the
2926 * following algorithms allow.
2928 * A SCTP receiver MUST NOT generate more than one SACK for every
2929 * incoming packet, other than to update the offered window as the
2930 * receiving application consumes new data.
2932 * Verification Tag: 8.5 Verification Tag [Normal verification]
2935 * (endpoint, asoc, chunk)
2938 * (asoc, reply_msg, msg_up, timers, counters)
2940 * The return value is the disposition of the chunk.
2942 sctp_disposition_t
sctp_sf_eat_data_6_2(struct net
*net
,
2943 const struct sctp_endpoint
*ep
,
2944 const struct sctp_association
*asoc
,
2945 const sctp_subtype_t type
,
2947 sctp_cmd_seq_t
*commands
)
2949 struct sctp_chunk
*chunk
= arg
;
2950 sctp_arg_t force
= SCTP_NOFORCE();
2953 if (!sctp_vtag_verify(chunk
, asoc
)) {
2954 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2956 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2959 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2960 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2963 error
= sctp_eat_data(asoc
, chunk
, commands
);
2965 case SCTP_IERROR_NO_ERROR
:
2967 case SCTP_IERROR_HIGH_TSN
:
2968 case SCTP_IERROR_BAD_STREAM
:
2969 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2970 goto discard_noforce
;
2971 case SCTP_IERROR_DUP_TSN
:
2972 case SCTP_IERROR_IGNORE_TSN
:
2973 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2975 case SCTP_IERROR_NO_DATA
:
2977 case SCTP_IERROR_PROTO_VIOLATION
:
2978 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
2979 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
2984 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
2985 force
= SCTP_FORCE();
2987 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
2988 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2989 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2992 /* If this is the last chunk in a packet, we need to count it
2993 * toward sack generation. Note that we need to SACK every
2994 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2995 * THEM. We elect to NOT generate SACK's if the chunk fails
2996 * the verification tag test.
2998 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3000 * The SCTP endpoint MUST always acknowledge the reception of
3001 * each valid DATA chunk.
3003 * The guidelines on delayed acknowledgement algorithm
3004 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3005 * Specifically, an acknowledgement SHOULD be generated for at
3006 * least every second packet (not every second DATA chunk)
3007 * received, and SHOULD be generated within 200 ms of the
3008 * arrival of any unacknowledged DATA chunk. In some
3009 * situations it may be beneficial for an SCTP transmitter to
3010 * be more conservative than the algorithms detailed in this
3011 * document allow. However, an SCTP transmitter MUST NOT be
3012 * more aggressive than the following algorithms allow.
3014 if (chunk
->end_of_packet
)
3015 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3017 return SCTP_DISPOSITION_CONSUME
;
3020 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3022 * When a packet arrives with duplicate DATA chunk(s) and with
3023 * no new DATA chunk(s), the endpoint MUST immediately send a
3024 * SACK with no delay. If a packet arrives with duplicate
3025 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3026 * MAY immediately send a SACK. Normally receipt of duplicate
3027 * DATA chunks will occur when the original SACK chunk was lost
3028 * and the peer's RTO has expired. The duplicate TSN number(s)
3029 * SHOULD be reported in the SACK as duplicate.
3031 /* In our case, we split the MAY SACK advice up whether or not
3032 * the last chunk is a duplicate.'
3034 if (chunk
->end_of_packet
)
3035 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3036 return SCTP_DISPOSITION_DISCARD
;
3039 if (chunk
->end_of_packet
)
3040 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3042 return SCTP_DISPOSITION_DISCARD
;
3044 return SCTP_DISPOSITION_CONSUME
;
3049 * sctp_sf_eat_data_fast_4_4
3052 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3053 * DATA chunks without delay.
3055 * Verification Tag: 8.5 Verification Tag [Normal verification]
3057 * (endpoint, asoc, chunk)
3060 * (asoc, reply_msg, msg_up, timers, counters)
3062 * The return value is the disposition of the chunk.
3064 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(struct net
*net
,
3065 const struct sctp_endpoint
*ep
,
3066 const struct sctp_association
*asoc
,
3067 const sctp_subtype_t type
,
3069 sctp_cmd_seq_t
*commands
)
3071 struct sctp_chunk
*chunk
= arg
;
3074 if (!sctp_vtag_verify(chunk
, asoc
)) {
3075 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3077 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3080 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
3081 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3084 error
= sctp_eat_data(asoc
, chunk
, commands
);
3086 case SCTP_IERROR_NO_ERROR
:
3087 case SCTP_IERROR_HIGH_TSN
:
3088 case SCTP_IERROR_DUP_TSN
:
3089 case SCTP_IERROR_IGNORE_TSN
:
3090 case SCTP_IERROR_BAD_STREAM
:
3092 case SCTP_IERROR_NO_DATA
:
3094 case SCTP_IERROR_PROTO_VIOLATION
:
3095 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
3096 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3101 /* Go a head and force a SACK, since we are shutting down. */
3103 /* Implementor's Guide.
3105 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3106 * respond to each received packet containing one or more DATA chunk(s)
3107 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3109 if (chunk
->end_of_packet
) {
3110 /* We must delay the chunk creation since the cumulative
3111 * TSN has not been updated yet.
3113 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3114 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3115 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3116 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3120 return SCTP_DISPOSITION_CONSUME
;
3124 * Section: 6.2 Processing a Received SACK
3125 * D) Any time a SACK arrives, the endpoint performs the following:
3127 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3128 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3129 * increasing, a SACK whose Cumulative TSN Ack is less than the
3130 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3132 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3133 * of bytes still outstanding after processing the Cumulative TSN Ack
3134 * and the Gap Ack Blocks.
3136 * iii) If the SACK is missing a TSN that was previously
3137 * acknowledged via a Gap Ack Block (e.g., the data receiver
3138 * reneged on the data), then mark the corresponding DATA chunk
3139 * as available for retransmit: Mark it as missing for fast
3140 * retransmit as described in Section 7.2.4 and if no retransmit
3141 * timer is running for the destination address to which the DATA
3142 * chunk was originally transmitted, then T3-rtx is started for
3143 * that destination address.
3145 * Verification Tag: 8.5 Verification Tag [Normal verification]
3148 * (endpoint, asoc, chunk)
3151 * (asoc, reply_msg, msg_up, timers, counters)
3153 * The return value is the disposition of the chunk.
3155 sctp_disposition_t
sctp_sf_eat_sack_6_2(struct net
*net
,
3156 const struct sctp_endpoint
*ep
,
3157 const struct sctp_association
*asoc
,
3158 const sctp_subtype_t type
,
3160 sctp_cmd_seq_t
*commands
)
3162 struct sctp_chunk
*chunk
= arg
;
3163 sctp_sackhdr_t
*sackh
;
3166 if (!sctp_vtag_verify(chunk
, asoc
))
3167 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3169 /* Make sure that the SACK chunk has a valid length. */
3170 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3171 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3174 /* Pull the SACK chunk from the data buffer */
3175 sackh
= sctp_sm_pull_sack(chunk
);
3176 /* Was this a bogus SACK? */
3178 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3179 chunk
->subh
.sack_hdr
= sackh
;
3180 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3182 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3183 * Ack Point, then drop the SACK. Since Cumulative TSN
3184 * Ack is monotonically increasing, a SACK whose
3185 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3186 * Point indicates an out-of-order SACK.
3188 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3189 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
3190 asoc
->ctsn_ack_point
);
3192 return SCTP_DISPOSITION_DISCARD
;
3195 /* If Cumulative TSN Ack beyond the max tsn currently
3196 * send, terminating the association and respond to the
3197 * sender with an ABORT.
3199 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3200 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
3202 /* Return this SACK for further processing. */
3203 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_CHUNK(chunk
));
3205 /* Note: We do the rest of the work on the PROCESS_SACK
3208 return SCTP_DISPOSITION_CONSUME
;
3212 * Generate an ABORT in response to a packet.
3214 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3216 * 8) The receiver should respond to the sender of the OOTB packet with
3217 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3218 * MUST fill in the Verification Tag field of the outbound packet
3219 * with the value found in the Verification Tag field of the OOTB
3220 * packet and set the T-bit in the Chunk Flags to indicate that the
3221 * Verification Tag is reflected. After sending this ABORT, the
3222 * receiver of the OOTB packet shall discard the OOTB packet and take
3223 * no further action.
3227 * The return value is the disposition of the chunk.
3229 static sctp_disposition_t
sctp_sf_tabort_8_4_8(struct net
*net
,
3230 const struct sctp_endpoint
*ep
,
3231 const struct sctp_association
*asoc
,
3232 const sctp_subtype_t type
,
3234 sctp_cmd_seq_t
*commands
)
3236 struct sctp_packet
*packet
= NULL
;
3237 struct sctp_chunk
*chunk
= arg
;
3238 struct sctp_chunk
*abort
;
3240 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3243 /* Make an ABORT. The T bit will be set if the asoc
3246 abort
= sctp_make_abort(asoc
, chunk
, 0);
3248 sctp_ootb_pkt_free(packet
);
3249 return SCTP_DISPOSITION_NOMEM
;
3252 /* Reflect vtag if T-Bit is set */
3253 if (sctp_test_T_bit(abort
))
3254 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3256 /* Set the skb to the belonging sock for accounting. */
3257 abort
->skb
->sk
= ep
->base
.sk
;
3259 sctp_packet_append_chunk(packet
, abort
);
3261 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3262 SCTP_PACKET(packet
));
3264 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3266 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3267 return SCTP_DISPOSITION_CONSUME
;
3270 return SCTP_DISPOSITION_NOMEM
;
3274 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3275 * event as ULP notification for each cause included in the chunk.
3277 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3279 * The return value is the disposition of the chunk.
3281 sctp_disposition_t
sctp_sf_operr_notify(struct net
*net
,
3282 const struct sctp_endpoint
*ep
,
3283 const struct sctp_association
*asoc
,
3284 const sctp_subtype_t type
,
3286 sctp_cmd_seq_t
*commands
)
3288 struct sctp_chunk
*chunk
= arg
;
3291 if (!sctp_vtag_verify(chunk
, asoc
))
3292 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3294 /* Make sure that the ERROR chunk has a valid length. */
3295 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3296 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3298 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3299 if ((void *)err
!= (void *)chunk
->chunk_end
)
3300 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3301 (void *)err
, commands
);
3303 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3306 return SCTP_DISPOSITION_CONSUME
;
3310 * Process an inbound SHUTDOWN ACK.
3313 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3314 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3315 * peer, and remove all record of the association.
3317 * The return value is the disposition.
3319 sctp_disposition_t
sctp_sf_do_9_2_final(struct net
*net
,
3320 const struct sctp_endpoint
*ep
,
3321 const struct sctp_association
*asoc
,
3322 const sctp_subtype_t type
,
3324 sctp_cmd_seq_t
*commands
)
3326 struct sctp_chunk
*chunk
= arg
;
3327 struct sctp_chunk
*reply
;
3328 struct sctp_ulpevent
*ev
;
3330 if (!sctp_vtag_verify(chunk
, asoc
))
3331 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3333 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3334 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3335 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3337 /* 10.2 H) SHUTDOWN COMPLETE notification
3339 * When SCTP completes the shutdown procedures (section 9.2) this
3340 * notification is passed to the upper layer.
3342 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3343 0, 0, 0, NULL
, GFP_ATOMIC
);
3347 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3348 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3352 /* Do all the commands now (after allocation), so that we
3353 * have consistent state if memory allocation failes
3355 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3357 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3358 * stop the T2-shutdown timer,
3360 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3361 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3363 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3364 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3366 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3367 SCTP_STATE(SCTP_STATE_CLOSED
));
3368 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
3369 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3370 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3372 /* ...and remove all record of the association. */
3373 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3374 return SCTP_DISPOSITION_DELETE_TCB
;
3377 sctp_ulpevent_free(ev
);
3379 return SCTP_DISPOSITION_NOMEM
;
3383 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3385 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3386 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3387 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3388 * packet must fill in the Verification Tag field of the outbound
3389 * packet with the Verification Tag received in the SHUTDOWN ACK and
3390 * set the T-bit in the Chunk Flags to indicate that the Verification
3393 * 8) The receiver should respond to the sender of the OOTB packet with
3394 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3395 * MUST fill in the Verification Tag field of the outbound packet
3396 * with the value found in the Verification Tag field of the OOTB
3397 * packet and set the T-bit in the Chunk Flags to indicate that the
3398 * Verification Tag is reflected. After sending this ABORT, the
3399 * receiver of the OOTB packet shall discard the OOTB packet and take
3400 * no further action.
3402 sctp_disposition_t
sctp_sf_ootb(struct net
*net
,
3403 const struct sctp_endpoint
*ep
,
3404 const struct sctp_association
*asoc
,
3405 const sctp_subtype_t type
,
3407 sctp_cmd_seq_t
*commands
)
3409 struct sctp_chunk
*chunk
= arg
;
3410 struct sk_buff
*skb
= chunk
->skb
;
3411 sctp_chunkhdr_t
*ch
;
3414 int ootb_shut_ack
= 0;
3415 int ootb_cookie_ack
= 0;
3417 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3419 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3421 /* Report violation if the chunk is less then minimal */
3422 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3423 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3426 /* Now that we know we at least have a chunk header,
3427 * do things that are type appropriate.
3429 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3432 /* RFC 2960, Section 3.3.7
3433 * Moreover, under any circumstances, an endpoint that
3434 * receives an ABORT MUST NOT respond to that ABORT by
3435 * sending an ABORT of its own.
3437 if (SCTP_CID_ABORT
== ch
->type
)
3438 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3440 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3441 * or a COOKIE ACK the SCTP Packet should be silently
3445 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
3446 ootb_cookie_ack
= 1;
3448 if (SCTP_CID_ERROR
== ch
->type
) {
3449 sctp_walk_errors(err
, ch
) {
3450 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
) {
3451 ootb_cookie_ack
= 1;
3457 /* Report violation if chunk len overflows */
3458 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3459 if (ch_end
> skb_tail_pointer(skb
))
3460 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3463 ch
= (sctp_chunkhdr_t
*) ch_end
;
3464 } while (ch_end
< skb_tail_pointer(skb
));
3467 return sctp_sf_shut_8_4_5(net
, ep
, asoc
, type
, arg
, commands
);
3468 else if (ootb_cookie_ack
)
3469 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3471 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
3475 * Handle an "Out of the blue" SHUTDOWN ACK.
3477 * Section: 8.4 5, sctpimpguide 2.41.
3479 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3480 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3481 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3482 * packet must fill in the Verification Tag field of the outbound
3483 * packet with the Verification Tag received in the SHUTDOWN ACK and
3484 * set the T-bit in the Chunk Flags to indicate that the Verification
3488 * (endpoint, asoc, type, arg, commands)
3491 * (sctp_disposition_t)
3493 * The return value is the disposition of the chunk.
3495 static sctp_disposition_t
sctp_sf_shut_8_4_5(struct net
*net
,
3496 const struct sctp_endpoint
*ep
,
3497 const struct sctp_association
*asoc
,
3498 const sctp_subtype_t type
,
3500 sctp_cmd_seq_t
*commands
)
3502 struct sctp_packet
*packet
= NULL
;
3503 struct sctp_chunk
*chunk
= arg
;
3504 struct sctp_chunk
*shut
;
3506 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3509 /* Make an SHUTDOWN_COMPLETE.
3510 * The T bit will be set if the asoc is NULL.
3512 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3514 sctp_ootb_pkt_free(packet
);
3515 return SCTP_DISPOSITION_NOMEM
;
3518 /* Reflect vtag if T-Bit is set */
3519 if (sctp_test_T_bit(shut
))
3520 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3522 /* Set the skb to the belonging sock for accounting. */
3523 shut
->skb
->sk
= ep
->base
.sk
;
3525 sctp_packet_append_chunk(packet
, shut
);
3527 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3528 SCTP_PACKET(packet
));
3530 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3532 /* If the chunk length is invalid, we don't want to process
3533 * the reset of the packet.
3535 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3536 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3538 /* We need to discard the rest of the packet to prevent
3539 * potential bomming attacks from additional bundled chunks.
3540 * This is documented in SCTP Threats ID.
3542 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3545 return SCTP_DISPOSITION_NOMEM
;
3549 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3551 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3552 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3553 * procedures in section 8.4 SHOULD be followed, in other words it
3554 * should be treated as an Out Of The Blue packet.
3555 * [This means that we do NOT check the Verification Tag on these
3559 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(struct net
*net
,
3560 const struct sctp_endpoint
*ep
,
3561 const struct sctp_association
*asoc
,
3562 const sctp_subtype_t type
,
3564 sctp_cmd_seq_t
*commands
)
3566 struct sctp_chunk
*chunk
= arg
;
3568 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3569 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3570 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3573 /* Although we do have an association in this case, it corresponds
3574 * to a restarted association. So the packet is treated as an OOTB
3575 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3576 * called with a NULL association.
3578 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3580 return sctp_sf_shut_8_4_5(net
, ep
, NULL
, type
, arg
, commands
);
3583 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3584 sctp_disposition_t
sctp_sf_do_asconf(struct net
*net
,
3585 const struct sctp_endpoint
*ep
,
3586 const struct sctp_association
*asoc
,
3587 const sctp_subtype_t type
, void *arg
,
3588 sctp_cmd_seq_t
*commands
)
3590 struct sctp_chunk
*chunk
= arg
;
3591 struct sctp_chunk
*asconf_ack
= NULL
;
3592 struct sctp_paramhdr
*err_param
= NULL
;
3593 sctp_addiphdr_t
*hdr
;
3596 if (!sctp_vtag_verify(chunk
, asoc
)) {
3597 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3599 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3602 /* ADD-IP: Section 4.1.1
3603 * This chunk MUST be sent in an authenticated way by using
3604 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3605 * is received unauthenticated it MUST be silently discarded as
3606 * described in [I-D.ietf-tsvwg-sctp-auth].
3608 if (!net
->sctp
.addip_noauth
&& !chunk
->auth
)
3609 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3611 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3612 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3613 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3616 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3617 serial
= ntohl(hdr
->serial
);
3619 /* Verify the ASCONF chunk before processing it. */
3620 if (!sctp_verify_asconf(asoc
, chunk
, true, &err_param
))
3621 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3622 (void *)err_param
, commands
);
3624 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3625 * the endpoint stored in a new association variable
3626 * 'Peer-Serial-Number'.
3628 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3629 /* If this is the first instance of ASCONF in the packet,
3630 * we can clean our old ASCONF-ACKs.
3632 if (!chunk
->has_asconf
)
3633 sctp_assoc_clean_asconf_ack_cache(asoc
);
3635 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3636 * expected, process the ASCONF as described below and after
3637 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3638 * the response packet and cache a copy of it (in the event it
3639 * later needs to be retransmitted).
3641 * Essentially, do V1-V5.
3643 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3646 return SCTP_DISPOSITION_NOMEM
;
3647 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3649 * If the value found in the Sequence Number is less than the
3650 * ('Peer- Sequence-Number' + 1), simply skip to the next
3651 * ASCONF, and include in the outbound response packet
3652 * any previously cached ASCONF-ACK response that was
3653 * sent and saved that matches the Sequence Number of the
3654 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3655 * Chunk exists. This will occur when an older ASCONF
3656 * arrives out of order. In such a case, the receiver
3657 * should skip the ASCONF Chunk and not include ASCONF-ACK
3658 * Chunk for that chunk.
3660 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3662 return SCTP_DISPOSITION_DISCARD
;
3664 /* Reset the transport so that we select the correct one
3665 * this time around. This is to make sure that we don't
3666 * accidentally use a stale transport that's been removed.
3668 asconf_ack
->transport
= NULL
;
3670 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3671 * it must be either a stale packet or from an attacker.
3673 return SCTP_DISPOSITION_DISCARD
;
3676 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3677 * containing the ASCONF-ACK Chunks MUST be the source address of
3678 * the SCTP packet that held the ASCONF Chunks.
3680 * To do this properly, we'll set the destination address of the chunk
3681 * and at the transmit time, will try look up the transport to use.
3682 * Since ASCONFs may be bundled, the correct transport may not be
3683 * created until we process the entire packet, thus this workaround.
3685 asconf_ack
->dest
= chunk
->source
;
3686 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3687 if (asoc
->new_transport
) {
3688 sctp_sf_heartbeat(ep
, asoc
, type
, asoc
->new_transport
, commands
);
3689 ((struct sctp_association
*)asoc
)->new_transport
= NULL
;
3692 return SCTP_DISPOSITION_CONSUME
;
3696 * ADDIP Section 4.3 General rules for address manipulation
3697 * When building TLV parameters for the ASCONF Chunk that will add or
3698 * delete IP addresses the D0 to D13 rules should be applied:
3700 sctp_disposition_t
sctp_sf_do_asconf_ack(struct net
*net
,
3701 const struct sctp_endpoint
*ep
,
3702 const struct sctp_association
*asoc
,
3703 const sctp_subtype_t type
, void *arg
,
3704 sctp_cmd_seq_t
*commands
)
3706 struct sctp_chunk
*asconf_ack
= arg
;
3707 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3708 struct sctp_chunk
*abort
;
3709 struct sctp_paramhdr
*err_param
= NULL
;
3710 sctp_addiphdr_t
*addip_hdr
;
3711 __u32 sent_serial
, rcvd_serial
;
3713 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3714 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3716 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3719 /* ADD-IP, Section 4.1.2:
3720 * This chunk MUST be sent in an authenticated way by using
3721 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3722 * is received unauthenticated it MUST be silently discarded as
3723 * described in [I-D.ietf-tsvwg-sctp-auth].
3725 if (!net
->sctp
.addip_noauth
&& !asconf_ack
->auth
)
3726 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3728 /* Make sure that the ADDIP chunk has a valid length. */
3729 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3730 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3733 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3734 rcvd_serial
= ntohl(addip_hdr
->serial
);
3736 /* Verify the ASCONF-ACK chunk before processing it. */
3737 if (!sctp_verify_asconf(asoc
, asconf_ack
, false, &err_param
))
3738 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3739 (void *)err_param
, commands
);
3742 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3743 sent_serial
= ntohl(addip_hdr
->serial
);
3745 sent_serial
= asoc
->addip_serial
- 1;
3748 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3749 * equal to the next serial number to be used but no ASCONF chunk is
3750 * outstanding the endpoint MUST ABORT the association. Note that a
3751 * sequence number is greater than if it is no more than 2^^31-1
3752 * larger than the current sequence number (using serial arithmetic).
3754 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3755 !(asoc
->addip_last_asconf
)) {
3756 abort
= sctp_make_abort(asoc
, asconf_ack
,
3757 sizeof(sctp_errhdr_t
));
3759 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3760 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3763 /* We are going to ABORT, so we might as well stop
3764 * processing the rest of the chunks in the packet.
3766 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3767 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3768 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3769 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3770 SCTP_ERROR(ECONNABORTED
));
3771 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3772 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3773 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3774 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3775 return SCTP_DISPOSITION_ABORT
;
3778 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3779 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3780 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3782 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3784 /* Successfully processed ASCONF_ACK. We can
3785 * release the next asconf if we have one.
3787 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3789 return SCTP_DISPOSITION_CONSUME
;
3792 abort
= sctp_make_abort(asoc
, asconf_ack
,
3793 sizeof(sctp_errhdr_t
));
3795 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3796 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3799 /* We are going to ABORT, so we might as well stop
3800 * processing the rest of the chunks in the packet.
3802 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3803 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3804 SCTP_ERROR(ECONNABORTED
));
3805 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3806 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3807 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3808 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3809 return SCTP_DISPOSITION_ABORT
;
3812 return SCTP_DISPOSITION_DISCARD
;
3816 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3818 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3819 * its cumulative TSN point to the value carried in the FORWARD TSN
3820 * chunk, and then MUST further advance its cumulative TSN point locally
3822 * After the above processing, the data receiver MUST stop reporting any
3823 * missing TSNs earlier than or equal to the new cumulative TSN point.
3825 * Verification Tag: 8.5 Verification Tag [Normal verification]
3827 * The return value is the disposition of the chunk.
3829 sctp_disposition_t
sctp_sf_eat_fwd_tsn(struct net
*net
,
3830 const struct sctp_endpoint
*ep
,
3831 const struct sctp_association
*asoc
,
3832 const sctp_subtype_t type
,
3834 sctp_cmd_seq_t
*commands
)
3836 struct sctp_chunk
*chunk
= arg
;
3837 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3838 struct sctp_fwdtsn_skip
*skip
;
3842 if (!sctp_vtag_verify(chunk
, asoc
)) {
3843 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3845 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3848 /* Make sure that the FORWARD_TSN chunk has valid length. */
3849 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3850 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3853 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3854 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3855 len
= ntohs(chunk
->chunk_hdr
->length
);
3856 len
-= sizeof(struct sctp_chunkhdr
);
3857 skb_pull(chunk
->skb
, len
);
3859 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3860 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
3862 /* The TSN is too high--silently discard the chunk and count on it
3863 * getting retransmitted later.
3865 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3866 goto discard_noforce
;
3868 /* Silently discard the chunk if stream-id is not valid */
3869 sctp_walk_fwdtsn(skip
, chunk
) {
3870 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3871 goto discard_noforce
;
3874 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3875 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3876 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3879 /* Count this as receiving DATA. */
3880 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
3881 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3882 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3885 /* FIXME: For now send a SACK, but DATA processing may
3888 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3890 return SCTP_DISPOSITION_CONSUME
;
3893 return SCTP_DISPOSITION_DISCARD
;
3896 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3898 const struct sctp_endpoint
*ep
,
3899 const struct sctp_association
*asoc
,
3900 const sctp_subtype_t type
,
3902 sctp_cmd_seq_t
*commands
)
3904 struct sctp_chunk
*chunk
= arg
;
3905 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3906 struct sctp_fwdtsn_skip
*skip
;
3910 if (!sctp_vtag_verify(chunk
, asoc
)) {
3911 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3913 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3916 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3917 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3918 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3921 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3922 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3923 len
= ntohs(chunk
->chunk_hdr
->length
);
3924 len
-= sizeof(struct sctp_chunkhdr
);
3925 skb_pull(chunk
->skb
, len
);
3927 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3928 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
3930 /* The TSN is too high--silently discard the chunk and count on it
3931 * getting retransmitted later.
3933 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3936 /* Silently discard the chunk if stream-id is not valid */
3937 sctp_walk_fwdtsn(skip
, chunk
) {
3938 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3942 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3943 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3944 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3947 /* Go a head and force a SACK, since we are shutting down. */
3949 /* Implementor's Guide.
3951 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3952 * respond to each received packet containing one or more DATA chunk(s)
3953 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3955 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3956 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3957 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3958 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3960 return SCTP_DISPOSITION_CONSUME
;
3964 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3966 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3967 * Identifier field. If this algorithm was not specified by the
3968 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3969 * during association setup, the AUTH chunk and all chunks after it MUST
3970 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3971 * defined in Section 4.1.
3973 * If an endpoint with no shared key receives a Shared Key Identifier
3974 * other than 0, it MUST silently discard all authenticated chunks. If
3975 * the endpoint has at least one endpoint pair shared key for the peer,
3976 * it MUST use the key specified by the Shared Key Identifier if a
3977 * key has been configured for that Shared Key Identifier. If no
3978 * endpoint pair shared key has been configured for that Shared Key
3979 * Identifier, all authenticated chunks MUST be silently discarded.
3981 * Verification Tag: 8.5 Verification Tag [Normal verification]
3983 * The return value is the disposition of the chunk.
3985 static sctp_ierror_t
sctp_sf_authenticate(struct net
*net
,
3986 const struct sctp_endpoint
*ep
,
3987 const struct sctp_association
*asoc
,
3988 const sctp_subtype_t type
,
3989 struct sctp_chunk
*chunk
)
3991 struct sctp_authhdr
*auth_hdr
;
3992 struct sctp_hmac
*hmac
;
3993 unsigned int sig_len
;
3998 /* Pull in the auth header, so we can do some more verification */
3999 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4000 chunk
->subh
.auth_hdr
= auth_hdr
;
4001 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
4003 /* Make sure that we support the HMAC algorithm from the auth
4006 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
4007 return SCTP_IERROR_AUTH_BAD_HMAC
;
4009 /* Make sure that the provided shared key identifier has been
4012 key_id
= ntohs(auth_hdr
->shkey_id
);
4013 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
4014 return SCTP_IERROR_AUTH_BAD_KEYID
;
4017 /* Make sure that the length of the signature matches what
4020 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
4021 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
4022 if (sig_len
!= hmac
->hmac_len
)
4023 return SCTP_IERROR_PROTO_VIOLATION
;
4025 /* Now that we've done validation checks, we can compute and
4026 * verify the hmac. The steps involved are:
4027 * 1. Save the digest from the chunk.
4028 * 2. Zero out the digest in the chunk.
4029 * 3. Compute the new digest
4030 * 4. Compare saved and new digests.
4032 digest
= auth_hdr
->hmac
;
4033 skb_pull(chunk
->skb
, sig_len
);
4035 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
4039 memset(digest
, 0, sig_len
);
4041 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
4042 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
4045 /* Discard the packet if the digests do not match */
4046 if (memcmp(save_digest
, digest
, sig_len
)) {
4048 return SCTP_IERROR_BAD_SIG
;
4054 return SCTP_IERROR_NO_ERROR
;
4056 return SCTP_IERROR_NOMEM
;
4059 sctp_disposition_t
sctp_sf_eat_auth(struct net
*net
,
4060 const struct sctp_endpoint
*ep
,
4061 const struct sctp_association
*asoc
,
4062 const sctp_subtype_t type
,
4064 sctp_cmd_seq_t
*commands
)
4066 struct sctp_authhdr
*auth_hdr
;
4067 struct sctp_chunk
*chunk
= arg
;
4068 struct sctp_chunk
*err_chunk
;
4069 sctp_ierror_t error
;
4071 /* Make sure that the peer has AUTH capable */
4072 if (!asoc
->peer
.auth_capable
)
4073 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
4075 if (!sctp_vtag_verify(chunk
, asoc
)) {
4076 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
4078 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4081 /* Make sure that the AUTH chunk has valid length. */
4082 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
4083 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4086 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4087 error
= sctp_sf_authenticate(net
, ep
, asoc
, type
, chunk
);
4089 case SCTP_IERROR_AUTH_BAD_HMAC
:
4090 /* Generate the ERROR chunk and discard the rest
4093 err_chunk
= sctp_make_op_error(asoc
, chunk
,
4094 SCTP_ERROR_UNSUP_HMAC
,
4098 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4099 SCTP_CHUNK(err_chunk
));
4102 case SCTP_IERROR_AUTH_BAD_KEYID
:
4103 case SCTP_IERROR_BAD_SIG
:
4104 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4106 case SCTP_IERROR_PROTO_VIOLATION
:
4107 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4110 case SCTP_IERROR_NOMEM
:
4111 return SCTP_DISPOSITION_NOMEM
;
4113 default: /* Prevent gcc warnings */
4117 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4118 struct sctp_ulpevent
*ev
;
4120 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4121 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4126 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4130 return SCTP_DISPOSITION_CONSUME
;
4134 * Process an unknown chunk.
4136 * Section: 3.2. Also, 2.1 in the implementor's guide.
4138 * Chunk Types are encoded such that the highest-order two bits specify
4139 * the action that must be taken if the processing endpoint does not
4140 * recognize the Chunk Type.
4142 * 00 - Stop processing this SCTP packet and discard it, do not process
4143 * any further chunks within it.
4145 * 01 - Stop processing this SCTP packet and discard it, do not process
4146 * any further chunks within it, and report the unrecognized
4147 * chunk in an 'Unrecognized Chunk Type'.
4149 * 10 - Skip this chunk and continue processing.
4151 * 11 - Skip this chunk and continue processing, but report in an ERROR
4152 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4154 * The return value is the disposition of the chunk.
4156 sctp_disposition_t
sctp_sf_unk_chunk(struct net
*net
,
4157 const struct sctp_endpoint
*ep
,
4158 const struct sctp_association
*asoc
,
4159 const sctp_subtype_t type
,
4161 sctp_cmd_seq_t
*commands
)
4163 struct sctp_chunk
*unk_chunk
= arg
;
4164 struct sctp_chunk
*err_chunk
;
4165 sctp_chunkhdr_t
*hdr
;
4167 pr_debug("%s: processing unknown chunk id:%d\n", __func__
, type
.chunk
);
4169 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4170 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4172 /* Make sure that the chunk has a valid length.
4173 * Since we don't know the chunk type, we use a general
4174 * chunkhdr structure to make a comparison.
4176 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
4177 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4180 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4181 case SCTP_CID_ACTION_DISCARD
:
4182 /* Discard the packet. */
4183 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4184 case SCTP_CID_ACTION_DISCARD_ERR
:
4185 /* Generate an ERROR chunk as response. */
4186 hdr
= unk_chunk
->chunk_hdr
;
4187 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4188 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4189 WORD_ROUND(ntohs(hdr
->length
)),
4192 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4193 SCTP_CHUNK(err_chunk
));
4196 /* Discard the packet. */
4197 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4198 return SCTP_DISPOSITION_CONSUME
;
4199 case SCTP_CID_ACTION_SKIP
:
4200 /* Skip the chunk. */
4201 return SCTP_DISPOSITION_DISCARD
;
4202 case SCTP_CID_ACTION_SKIP_ERR
:
4203 /* Generate an ERROR chunk as response. */
4204 hdr
= unk_chunk
->chunk_hdr
;
4205 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4206 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4207 WORD_ROUND(ntohs(hdr
->length
)),
4210 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4211 SCTP_CHUNK(err_chunk
));
4213 /* Skip the chunk. */
4214 return SCTP_DISPOSITION_CONSUME
;
4219 return SCTP_DISPOSITION_DISCARD
;
4223 * Discard the chunk.
4225 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4226 * [Too numerous to mention...]
4227 * Verification Tag: No verification needed.
4229 * (endpoint, asoc, chunk)
4232 * (asoc, reply_msg, msg_up, timers, counters)
4234 * The return value is the disposition of the chunk.
4236 sctp_disposition_t
sctp_sf_discard_chunk(struct net
*net
,
4237 const struct sctp_endpoint
*ep
,
4238 const struct sctp_association
*asoc
,
4239 const sctp_subtype_t type
,
4241 sctp_cmd_seq_t
*commands
)
4243 struct sctp_chunk
*chunk
= arg
;
4245 /* Make sure that the chunk has a valid length.
4246 * Since we don't know the chunk type, we use a general
4247 * chunkhdr structure to make a comparison.
4249 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4250 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4253 pr_debug("%s: chunk:%d is discarded\n", __func__
, type
.chunk
);
4255 return SCTP_DISPOSITION_DISCARD
;
4259 * Discard the whole packet.
4263 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4264 * silently discard the OOTB packet and take no further action.
4266 * Verification Tag: No verification necessary
4269 * (endpoint, asoc, chunk)
4272 * (asoc, reply_msg, msg_up, timers, counters)
4274 * The return value is the disposition of the chunk.
4276 sctp_disposition_t
sctp_sf_pdiscard(struct net
*net
,
4277 const struct sctp_endpoint
*ep
,
4278 const struct sctp_association
*asoc
,
4279 const sctp_subtype_t type
,
4281 sctp_cmd_seq_t
*commands
)
4283 SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_DISCARDS
);
4284 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4286 return SCTP_DISPOSITION_CONSUME
;
4291 * The other end is violating protocol.
4293 * Section: Not specified
4294 * Verification Tag: Not specified
4296 * (endpoint, asoc, chunk)
4299 * (asoc, reply_msg, msg_up, timers, counters)
4301 * We simply tag the chunk as a violation. The state machine will log
4302 * the violation and continue.
4304 sctp_disposition_t
sctp_sf_violation(struct net
*net
,
4305 const struct sctp_endpoint
*ep
,
4306 const struct sctp_association
*asoc
,
4307 const sctp_subtype_t type
,
4309 sctp_cmd_seq_t
*commands
)
4311 struct sctp_chunk
*chunk
= arg
;
4313 /* Make sure that the chunk has a valid length. */
4314 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4315 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4318 return SCTP_DISPOSITION_VIOLATION
;
4322 * Common function to handle a protocol violation.
4324 static sctp_disposition_t
sctp_sf_abort_violation(
4326 const struct sctp_endpoint
*ep
,
4327 const struct sctp_association
*asoc
,
4329 sctp_cmd_seq_t
*commands
,
4330 const __u8
*payload
,
4331 const size_t paylen
)
4333 struct sctp_packet
*packet
= NULL
;
4334 struct sctp_chunk
*chunk
= arg
;
4335 struct sctp_chunk
*abort
= NULL
;
4337 /* SCTP-AUTH, Section 6.3:
4338 * It should be noted that if the receiver wants to tear
4339 * down an association in an authenticated way only, the
4340 * handling of malformed packets should not result in
4341 * tearing down the association.
4343 * This means that if we only want to abort associations
4344 * in an authenticated way (i.e AUTH+ABORT), then we
4345 * can't destroy this association just because the packet
4348 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4351 /* Make the abort chunk. */
4352 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4357 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4358 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4359 !asoc
->peer
.i
.init_tag
) {
4360 sctp_initack_chunk_t
*initack
;
4362 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4363 if (!sctp_chunk_length_valid(chunk
,
4364 sizeof(sctp_initack_chunk_t
)))
4365 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4367 unsigned int inittag
;
4369 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4370 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4375 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4376 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4378 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4379 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4380 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4381 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4382 SCTP_ERROR(ECONNREFUSED
));
4383 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4384 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4386 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4387 SCTP_ERROR(ECONNABORTED
));
4388 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4389 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4390 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4393 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
4398 if (sctp_test_T_bit(abort
))
4399 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4401 abort
->skb
->sk
= ep
->base
.sk
;
4403 sctp_packet_append_chunk(packet
, abort
);
4405 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4406 SCTP_PACKET(packet
));
4408 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4411 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4414 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4415 return SCTP_DISPOSITION_ABORT
;
4418 sctp_chunk_free(abort
);
4420 return SCTP_DISPOSITION_NOMEM
;
4424 * Handle a protocol violation when the chunk length is invalid.
4425 * "Invalid" length is identified as smaller than the minimal length a
4426 * given chunk can be. For example, a SACK chunk has invalid length
4427 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4429 * We inform the other end by sending an ABORT with a Protocol Violation
4432 * Section: Not specified
4433 * Verification Tag: Nothing to do
4435 * (endpoint, asoc, chunk)
4438 * (reply_msg, msg_up, counters)
4440 * Generate an ABORT chunk and terminate the association.
4442 static sctp_disposition_t
sctp_sf_violation_chunklen(
4444 const struct sctp_endpoint
*ep
,
4445 const struct sctp_association
*asoc
,
4446 const sctp_subtype_t type
,
4448 sctp_cmd_seq_t
*commands
)
4450 static const char err_str
[] = "The following chunk had invalid length:";
4452 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4457 * Handle a protocol violation when the parameter length is invalid.
4458 * If the length is smaller than the minimum length of a given parameter,
4459 * or accumulated length in multi parameters exceeds the end of the chunk,
4460 * the length is considered as invalid.
4462 static sctp_disposition_t
sctp_sf_violation_paramlen(
4464 const struct sctp_endpoint
*ep
,
4465 const struct sctp_association
*asoc
,
4466 const sctp_subtype_t type
,
4467 void *arg
, void *ext
,
4468 sctp_cmd_seq_t
*commands
)
4470 struct sctp_chunk
*chunk
= arg
;
4471 struct sctp_paramhdr
*param
= ext
;
4472 struct sctp_chunk
*abort
= NULL
;
4474 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4477 /* Make the abort chunk. */
4478 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4482 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4483 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4485 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4486 SCTP_ERROR(ECONNABORTED
));
4487 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4488 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4489 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4490 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4493 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4494 return SCTP_DISPOSITION_ABORT
;
4496 return SCTP_DISPOSITION_NOMEM
;
4499 /* Handle a protocol violation when the peer trying to advance the
4500 * cumulative tsn ack to a point beyond the max tsn currently sent.
4502 * We inform the other end by sending an ABORT with a Protocol Violation
4505 static sctp_disposition_t
sctp_sf_violation_ctsn(
4507 const struct sctp_endpoint
*ep
,
4508 const struct sctp_association
*asoc
,
4509 const sctp_subtype_t type
,
4511 sctp_cmd_seq_t
*commands
)
4513 static const char err_str
[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4515 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4519 /* Handle protocol violation of an invalid chunk bundling. For example,
4520 * when we have an association and we receive bundled INIT-ACK, or
4521 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4522 * statement from the specs. Additionally, there might be an attacker
4523 * on the path and we may not want to continue this communication.
4525 static sctp_disposition_t
sctp_sf_violation_chunk(
4527 const struct sctp_endpoint
*ep
,
4528 const struct sctp_association
*asoc
,
4529 const sctp_subtype_t type
,
4531 sctp_cmd_seq_t
*commands
)
4533 static const char err_str
[] = "The following chunk violates protocol:";
4536 return sctp_sf_violation(net
, ep
, asoc
, type
, arg
, commands
);
4538 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4541 /***************************************************************************
4542 * These are the state functions for handling primitive (Section 10) events.
4543 ***************************************************************************/
4545 * sctp_sf_do_prm_asoc
4547 * Section: 10.1 ULP-to-SCTP
4550 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4551 * outbound stream count)
4552 * -> association id [,destination transport addr list] [,outbound stream
4555 * This primitive allows the upper layer to initiate an association to a
4556 * specific peer endpoint.
4558 * The peer endpoint shall be specified by one of the transport addresses
4559 * which defines the endpoint (see Section 1.4). If the local SCTP
4560 * instance has not been initialized, the ASSOCIATE is considered an
4562 * [This is not relevant for the kernel implementation since we do all
4563 * initialization at boot time. It we hadn't initialized we wouldn't
4564 * get anywhere near this code.]
4566 * An association id, which is a local handle to the SCTP association,
4567 * will be returned on successful establishment of the association. If
4568 * SCTP is not able to open an SCTP association with the peer endpoint,
4569 * an error is returned.
4570 * [In the kernel implementation, the struct sctp_association needs to
4571 * be created BEFORE causing this primitive to run.]
4573 * Other association parameters may be returned, including the
4574 * complete destination transport addresses of the peer as well as the
4575 * outbound stream count of the local endpoint. One of the transport
4576 * address from the returned destination addresses will be selected by
4577 * the local endpoint as default primary path for sending SCTP packets
4578 * to this peer. The returned "destination transport addr list" can
4579 * be used by the ULP to change the default primary path or to force
4580 * sending a packet to a specific transport address. [All of this
4581 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4584 * Mandatory attributes:
4586 * o local SCTP instance name - obtained from the INITIALIZE operation.
4587 * [This is the argument asoc.]
4588 * o destination transport addr - specified as one of the transport
4589 * addresses of the peer endpoint with which the association is to be
4591 * [This is asoc->peer.active_path.]
4592 * o outbound stream count - the number of outbound streams the ULP
4593 * would like to open towards this peer endpoint.
4594 * [BUG: This is not currently implemented.]
4595 * Optional attributes:
4599 * The return value is a disposition.
4601 sctp_disposition_t
sctp_sf_do_prm_asoc(struct net
*net
,
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 struct sctp_chunk
*repl
;
4609 struct sctp_association
*my_asoc
;
4611 /* The comment below says that we enter COOKIE-WAIT AFTER
4612 * sending the INIT, but that doesn't actually work in our
4615 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4616 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4618 /* RFC 2960 5.1 Normal Establishment of an Association
4620 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4621 * must provide its Verification Tag (Tag_A) in the Initiate
4622 * Tag field. Tag_A SHOULD be a random number in the range of
4623 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4626 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4630 /* Choose transport for INIT. */
4631 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4634 /* Cast away the const modifier, as we want to just
4635 * rerun it through as a sideffect.
4637 my_asoc
= (struct sctp_association
*)asoc
;
4638 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4640 /* After sending the INIT, "A" starts the T1-init timer and
4641 * enters the COOKIE-WAIT state.
4643 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4644 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4645 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4646 return SCTP_DISPOSITION_CONSUME
;
4649 return SCTP_DISPOSITION_NOMEM
;
4653 * Process the SEND primitive.
4655 * Section: 10.1 ULP-to-SCTP
4658 * Format: SEND(association id, buffer address, byte count [,context]
4659 * [,stream id] [,life time] [,destination transport address]
4660 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4663 * This is the main method to send user data via SCTP.
4665 * Mandatory attributes:
4667 * o association id - local handle to the SCTP association
4669 * o buffer address - the location where the user message to be
4670 * transmitted is stored;
4672 * o byte count - The size of the user data in number of bytes;
4674 * Optional attributes:
4676 * o context - an optional 32 bit integer that will be carried in the
4677 * sending failure notification to the ULP if the transportation of
4678 * this User Message fails.
4680 * o stream id - to indicate which stream to send the data on. If not
4681 * specified, stream 0 will be used.
4683 * o life time - specifies the life time of the user data. The user data
4684 * will not be sent by SCTP after the life time expires. This
4685 * parameter can be used to avoid efforts to transmit stale
4686 * user messages. SCTP notifies the ULP if the data cannot be
4687 * initiated to transport (i.e. sent to the destination via SCTP's
4688 * send primitive) within the life time variable. However, the
4689 * user data will be transmitted if SCTP has attempted to transmit a
4690 * chunk before the life time expired.
4692 * o destination transport address - specified as one of the destination
4693 * transport addresses of the peer endpoint to which this packet
4694 * should be sent. Whenever possible, SCTP should use this destination
4695 * transport address for sending the packets, instead of the current
4698 * o unorder flag - this flag, if present, indicates that the user
4699 * would like the data delivered in an unordered fashion to the peer
4700 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4703 * o no-bundle flag - instructs SCTP not to bundle this user data with
4704 * other outbound DATA chunks. SCTP MAY still bundle even when
4705 * this flag is present, when faced with network congestion.
4707 * o payload protocol-id - A 32 bit unsigned integer that is to be
4708 * passed to the peer indicating the type of payload protocol data
4709 * being transmitted. This value is passed as opaque data by SCTP.
4711 * The return value is the disposition.
4713 sctp_disposition_t
sctp_sf_do_prm_send(struct net
*net
,
4714 const struct sctp_endpoint
*ep
,
4715 const struct sctp_association
*asoc
,
4716 const sctp_subtype_t type
,
4718 sctp_cmd_seq_t
*commands
)
4720 struct sctp_datamsg
*msg
= arg
;
4722 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4723 return SCTP_DISPOSITION_CONSUME
;
4727 * Process the SHUTDOWN primitive.
4732 * Format: SHUTDOWN(association id)
4735 * Gracefully closes an association. Any locally queued user data
4736 * will be delivered to the peer. The association will be terminated only
4737 * after the peer acknowledges all the SCTP packets sent. A success code
4738 * will be returned on successful termination of the association. If
4739 * attempting to terminate the association results in a failure, an error
4740 * code shall be returned.
4742 * Mandatory attributes:
4744 * o association id - local handle to the SCTP association
4746 * Optional attributes:
4750 * The return value is the disposition.
4752 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4754 const struct sctp_endpoint
*ep
,
4755 const struct sctp_association
*asoc
,
4756 const sctp_subtype_t type
,
4758 sctp_cmd_seq_t
*commands
)
4762 /* From 9.2 Shutdown of an Association
4763 * Upon receipt of the SHUTDOWN primitive from its upper
4764 * layer, the endpoint enters SHUTDOWN-PENDING state and
4765 * remains there until all outstanding data has been
4766 * acknowledged by its peer. The endpoint accepts no new data
4767 * from its upper layer, but retransmits data to the far end
4768 * if necessary to fill gaps.
4770 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4771 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4773 disposition
= SCTP_DISPOSITION_CONSUME
;
4774 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4775 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
4782 * Process the ABORT primitive.
4787 * Format: Abort(association id [, cause code])
4790 * Ungracefully closes an association. Any locally queued user data
4791 * will be discarded and an ABORT chunk is sent to the peer. A success code
4792 * will be returned on successful abortion of the association. If
4793 * attempting to abort the association results in a failure, an error
4794 * code shall be returned.
4796 * Mandatory attributes:
4798 * o association id - local handle to the SCTP association
4800 * Optional attributes:
4802 * o cause code - reason of the abort to be passed to the peer
4806 * The return value is the disposition.
4808 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4810 const struct sctp_endpoint
*ep
,
4811 const struct sctp_association
*asoc
,
4812 const sctp_subtype_t type
,
4814 sctp_cmd_seq_t
*commands
)
4816 /* From 9.1 Abort of an Association
4817 * Upon receipt of the ABORT primitive from its upper
4818 * layer, the endpoint enters CLOSED state and
4819 * discard all outstanding data has been
4820 * acknowledged by its peer. The endpoint accepts no new data
4821 * from its upper layer, but retransmits data to the far end
4822 * if necessary to fill gaps.
4824 struct sctp_chunk
*abort
= arg
;
4825 sctp_disposition_t retval
;
4827 retval
= SCTP_DISPOSITION_CONSUME
;
4829 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4831 /* Even if we can't send the ABORT due to low memory delete the
4832 * TCB. This is a departure from our typical NOMEM handling.
4835 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4836 SCTP_ERROR(ECONNABORTED
));
4837 /* Delete the established association. */
4838 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4839 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4841 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4842 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4847 /* We tried an illegal operation on an association which is closed. */
4848 sctp_disposition_t
sctp_sf_error_closed(struct net
*net
,
4849 const struct sctp_endpoint
*ep
,
4850 const struct sctp_association
*asoc
,
4851 const sctp_subtype_t type
,
4853 sctp_cmd_seq_t
*commands
)
4855 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4856 return SCTP_DISPOSITION_CONSUME
;
4859 /* We tried an illegal operation on an association which is shutting
4862 sctp_disposition_t
sctp_sf_error_shutdown(struct net
*net
,
4863 const struct sctp_endpoint
*ep
,
4864 const struct sctp_association
*asoc
,
4865 const sctp_subtype_t type
,
4867 sctp_cmd_seq_t
*commands
)
4869 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4870 SCTP_ERROR(-ESHUTDOWN
));
4871 return SCTP_DISPOSITION_CONSUME
;
4875 * sctp_cookie_wait_prm_shutdown
4877 * Section: 4 Note: 2
4882 * The RFC does not explicitly address this issue, but is the route through the
4883 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4888 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4890 const struct sctp_endpoint
*ep
,
4891 const struct sctp_association
*asoc
,
4892 const sctp_subtype_t type
,
4894 sctp_cmd_seq_t
*commands
)
4896 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4897 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4899 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4900 SCTP_STATE(SCTP_STATE_CLOSED
));
4902 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
4904 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4906 return SCTP_DISPOSITION_DELETE_TCB
;
4910 * sctp_cookie_echoed_prm_shutdown
4912 * Section: 4 Note: 2
4917 * The RFC does not explcitly address this issue, but is the route through the
4918 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4923 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4925 const struct sctp_endpoint
*ep
,
4926 const struct sctp_association
*asoc
,
4927 const sctp_subtype_t type
,
4928 void *arg
, sctp_cmd_seq_t
*commands
)
4930 /* There is a single T1 timer, so we should be able to use
4931 * common function with the COOKIE-WAIT state.
4933 return sctp_sf_cookie_wait_prm_shutdown(net
, ep
, asoc
, type
, arg
, commands
);
4937 * sctp_sf_cookie_wait_prm_abort
4939 * Section: 4 Note: 2
4944 * The RFC does not explicitly address this issue, but is the route through the
4945 * state table when someone issues an abort while in COOKIE_WAIT state.
4950 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4952 const struct sctp_endpoint
*ep
,
4953 const struct sctp_association
*asoc
,
4954 const sctp_subtype_t type
,
4956 sctp_cmd_seq_t
*commands
)
4958 struct sctp_chunk
*abort
= arg
;
4959 sctp_disposition_t retval
;
4961 /* Stop T1-init timer */
4962 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4963 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4964 retval
= SCTP_DISPOSITION_CONSUME
;
4966 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4968 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4969 SCTP_STATE(SCTP_STATE_CLOSED
));
4971 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4973 /* Even if we can't send the ABORT due to low memory delete the
4974 * TCB. This is a departure from our typical NOMEM handling.
4977 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4978 SCTP_ERROR(ECONNREFUSED
));
4979 /* Delete the established association. */
4980 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4981 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4987 * sctp_sf_cookie_echoed_prm_abort
4989 * Section: 4 Note: 3
4994 * The RFC does not explcitly address this issue, but is the route through the
4995 * state table when someone issues an abort while in COOKIE_ECHOED state.
5000 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
5002 const struct sctp_endpoint
*ep
,
5003 const struct sctp_association
*asoc
,
5004 const sctp_subtype_t type
,
5006 sctp_cmd_seq_t
*commands
)
5008 /* There is a single T1 timer, so we should be able to use
5009 * common function with the COOKIE-WAIT state.
5011 return sctp_sf_cookie_wait_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5015 * sctp_sf_shutdown_pending_prm_abort
5020 * The RFC does not explicitly address this issue, but is the route through the
5021 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5026 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
5028 const struct sctp_endpoint
*ep
,
5029 const struct sctp_association
*asoc
,
5030 const sctp_subtype_t type
,
5032 sctp_cmd_seq_t
*commands
)
5034 /* Stop the T5-shutdown guard timer. */
5035 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5036 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5038 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5042 * sctp_sf_shutdown_sent_prm_abort
5047 * The RFC does not explicitly address this issue, but is the route through the
5048 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5053 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
5055 const struct sctp_endpoint
*ep
,
5056 const struct sctp_association
*asoc
,
5057 const sctp_subtype_t type
,
5059 sctp_cmd_seq_t
*commands
)
5061 /* Stop the T2-shutdown timer. */
5062 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5063 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5065 /* Stop the T5-shutdown guard timer. */
5066 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5067 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5069 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5073 * sctp_sf_cookie_echoed_prm_abort
5078 * The RFC does not explcitly address this issue, but is the route through the
5079 * state table when someone issues an abort while in COOKIE_ECHOED state.
5084 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
5086 const struct sctp_endpoint
*ep
,
5087 const struct sctp_association
*asoc
,
5088 const sctp_subtype_t type
,
5090 sctp_cmd_seq_t
*commands
)
5092 /* The same T2 timer, so we should be able to use
5093 * common function with the SHUTDOWN-SENT state.
5095 return sctp_sf_shutdown_sent_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5099 * Process the REQUESTHEARTBEAT primitive
5102 * J) Request Heartbeat
5104 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5108 * Instructs the local endpoint to perform a HeartBeat on the specified
5109 * destination transport address of the given association. The returned
5110 * result should indicate whether the transmission of the HEARTBEAT
5111 * chunk to the destination address is successful.
5113 * Mandatory attributes:
5115 * o association id - local handle to the SCTP association
5117 * o destination transport address - the transport address of the
5118 * association on which a heartbeat should be issued.
5120 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5122 const struct sctp_endpoint
*ep
,
5123 const struct sctp_association
*asoc
,
5124 const sctp_subtype_t type
,
5126 sctp_cmd_seq_t
*commands
)
5128 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5129 (struct sctp_transport
*)arg
, commands
))
5130 return SCTP_DISPOSITION_NOMEM
;
5133 * RFC 2960 (bis), section 8.3
5135 * D) Request an on-demand HEARTBEAT on a specific destination
5136 * transport address of a given association.
5138 * The endpoint should increment the respective error counter of
5139 * the destination transport address each time a HEARTBEAT is sent
5140 * to that address and not acknowledged within one RTO.
5143 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5144 SCTP_TRANSPORT(arg
));
5145 return SCTP_DISPOSITION_CONSUME
;
5149 * ADDIP Section 4.1 ASCONF Chunk Procedures
5150 * When an endpoint has an ASCONF signaled change to be sent to the
5151 * remote endpoint it should do A1 to A9
5153 sctp_disposition_t
sctp_sf_do_prm_asconf(struct net
*net
,
5154 const struct sctp_endpoint
*ep
,
5155 const struct sctp_association
*asoc
,
5156 const sctp_subtype_t type
,
5158 sctp_cmd_seq_t
*commands
)
5160 struct sctp_chunk
*chunk
= arg
;
5162 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5163 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5164 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5165 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5166 return SCTP_DISPOSITION_CONSUME
;
5170 * Ignore the primitive event
5172 * The return value is the disposition of the primitive.
5174 sctp_disposition_t
sctp_sf_ignore_primitive(
5176 const struct sctp_endpoint
*ep
,
5177 const struct sctp_association
*asoc
,
5178 const sctp_subtype_t type
,
5180 sctp_cmd_seq_t
*commands
)
5182 pr_debug("%s: primitive type:%d is ignored\n", __func__
,
5185 return SCTP_DISPOSITION_DISCARD
;
5188 /***************************************************************************
5189 * These are the state functions for the OTHER events.
5190 ***************************************************************************/
5193 * When the SCTP stack has no more user data to send or retransmit, this
5194 * notification is given to the user. Also, at the time when a user app
5195 * subscribes to this event, if there is no data to be sent or
5196 * retransmit, the stack will immediately send up this notification.
5198 sctp_disposition_t
sctp_sf_do_no_pending_tsn(
5200 const struct sctp_endpoint
*ep
,
5201 const struct sctp_association
*asoc
,
5202 const sctp_subtype_t type
,
5204 sctp_cmd_seq_t
*commands
)
5206 struct sctp_ulpevent
*event
;
5208 event
= sctp_ulpevent_make_sender_dry_event(asoc
, GFP_ATOMIC
);
5210 return SCTP_DISPOSITION_NOMEM
;
5212 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(event
));
5214 return SCTP_DISPOSITION_CONSUME
;
5218 * Start the shutdown negotiation.
5221 * Once all its outstanding data has been acknowledged, the endpoint
5222 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5223 * TSN Ack field the last sequential TSN it has received from the peer.
5224 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5225 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5226 * with the updated last sequential TSN received from its peer.
5228 * The return value is the disposition.
5230 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
5232 const struct sctp_endpoint
*ep
,
5233 const struct sctp_association
*asoc
,
5234 const sctp_subtype_t type
,
5236 sctp_cmd_seq_t
*commands
)
5238 struct sctp_chunk
*reply
;
5240 /* Once all its outstanding data has been acknowledged, the
5241 * endpoint shall send a SHUTDOWN chunk to its peer including
5242 * in the Cumulative TSN Ack field the last sequential TSN it
5243 * has received from the peer.
5245 reply
= sctp_make_shutdown(asoc
, NULL
);
5249 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5250 * T2-shutdown timer.
5252 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5254 /* It shall then start the T2-shutdown timer */
5255 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5256 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5258 /* RFC 4960 Section 9.2
5259 * The sender of the SHUTDOWN MAY also start an overall guard timer
5260 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5262 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5263 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5265 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5266 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5267 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5269 /* and enter the SHUTDOWN-SENT state. */
5270 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5271 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5273 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5275 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5278 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5280 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5282 return SCTP_DISPOSITION_CONSUME
;
5285 return SCTP_DISPOSITION_NOMEM
;
5289 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5293 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5294 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5295 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5296 * endpoint must re-send the SHUTDOWN ACK.
5298 * The return value is the disposition.
5300 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5302 const struct sctp_endpoint
*ep
,
5303 const struct sctp_association
*asoc
,
5304 const sctp_subtype_t type
,
5306 sctp_cmd_seq_t
*commands
)
5308 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5309 struct sctp_chunk
*reply
;
5311 /* There are 2 ways of getting here:
5312 * 1) called in response to a SHUTDOWN chunk
5313 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5315 * For the case (2), the arg parameter is set to NULL. We need
5316 * to check that we have a chunk before accessing it's fields.
5319 if (!sctp_vtag_verify(chunk
, asoc
))
5320 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
5322 /* Make sure that the SHUTDOWN chunk has a valid length. */
5323 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5324 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
5328 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5329 * shall send a SHUTDOWN ACK ...
5331 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5335 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5336 * the T2-shutdown timer.
5338 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5340 /* and start/restart a T2-shutdown timer of its own, */
5341 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5342 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5344 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5345 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5346 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5348 /* Enter the SHUTDOWN-ACK-SENT state. */
5349 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5350 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5352 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5354 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5357 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5359 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5361 return SCTP_DISPOSITION_CONSUME
;
5364 return SCTP_DISPOSITION_NOMEM
;
5368 * Ignore the event defined as other
5370 * The return value is the disposition of the event.
5372 sctp_disposition_t
sctp_sf_ignore_other(struct net
*net
,
5373 const struct sctp_endpoint
*ep
,
5374 const struct sctp_association
*asoc
,
5375 const sctp_subtype_t type
,
5377 sctp_cmd_seq_t
*commands
)
5379 pr_debug("%s: the event other type:%d is ignored\n",
5380 __func__
, type
.other
);
5382 return SCTP_DISPOSITION_DISCARD
;
5385 /************************************************************
5386 * These are the state functions for handling timeout events.
5387 ************************************************************/
5392 * Section: 6.3.3 Handle T3-rtx Expiration
5394 * Whenever the retransmission timer T3-rtx expires for a destination
5395 * address, do the following:
5398 * The return value is the disposition of the chunk.
5400 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(struct net
*net
,
5401 const struct sctp_endpoint
*ep
,
5402 const struct sctp_association
*asoc
,
5403 const sctp_subtype_t type
,
5405 sctp_cmd_seq_t
*commands
)
5407 struct sctp_transport
*transport
= arg
;
5409 SCTP_INC_STATS(net
, SCTP_MIB_T3_RTX_EXPIREDS
);
5411 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5412 if (asoc
->state
== SCTP_STATE_SHUTDOWN_PENDING
) {
5414 * We are here likely because the receiver had its rwnd
5415 * closed for a while and we have not been able to
5416 * transmit the locally queued data within the maximum
5417 * retransmission attempts limit. Start the T5
5418 * shutdown guard timer to give the receiver one last
5419 * chance and some additional time to recover before
5422 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START_ONCE
,
5423 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5425 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5426 SCTP_ERROR(ETIMEDOUT
));
5427 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5428 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5429 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5430 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5431 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5432 return SCTP_DISPOSITION_DELETE_TCB
;
5436 /* E1) For the destination address for which the timer
5437 * expires, adjust its ssthresh with rules defined in Section
5438 * 7.2.3 and set the cwnd <- MTU.
5441 /* E2) For the destination address for which the timer
5442 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5443 * maximum value discussed in rule C7 above (RTO.max) may be
5444 * used to provide an upper bound to this doubling operation.
5447 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5448 * outstanding DATA chunks for the address for which the
5449 * T3-rtx has expired will fit into a single packet, subject
5450 * to the MTU constraint for the path corresponding to the
5451 * destination transport address to which the retransmission
5452 * is being sent (this may be different from the address for
5453 * which the timer expires [see Section 6.4]). Call this
5454 * value K. Bundle and retransmit those K DATA chunks in a
5455 * single packet to the destination endpoint.
5457 * Note: Any DATA chunks that were sent to the address for
5458 * which the T3-rtx timer expired but did not fit in one MTU
5459 * (rule E3 above), should be marked for retransmission and
5460 * sent as soon as cwnd allows (normally when a SACK arrives).
5463 /* Do some failure management (Section 8.2). */
5464 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5466 /* NB: Rules E4 and F1 are implicit in R1. */
5467 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5469 return SCTP_DISPOSITION_CONSUME
;
5473 * Generate delayed SACK on timeout
5475 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5477 * The guidelines on delayed acknowledgement algorithm specified in
5478 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5479 * acknowledgement SHOULD be generated for at least every second packet
5480 * (not every second DATA chunk) received, and SHOULD be generated
5481 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5482 * some situations it may be beneficial for an SCTP transmitter to be
5483 * more conservative than the algorithms detailed in this document
5484 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5485 * the following algorithms allow.
5487 sctp_disposition_t
sctp_sf_do_6_2_sack(struct net
*net
,
5488 const struct sctp_endpoint
*ep
,
5489 const struct sctp_association
*asoc
,
5490 const sctp_subtype_t type
,
5492 sctp_cmd_seq_t
*commands
)
5494 SCTP_INC_STATS(net
, SCTP_MIB_DELAY_SACK_EXPIREDS
);
5495 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5496 return SCTP_DISPOSITION_CONSUME
;
5500 * sctp_sf_t1_init_timer_expire
5502 * Section: 4 Note: 2
5507 * RFC 2960 Section 4 Notes
5508 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5509 * and re-start the T1-init timer without changing state. This MUST
5510 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5511 * endpoint MUST abort the initialization process and report the
5512 * error to SCTP user.
5518 sctp_disposition_t
sctp_sf_t1_init_timer_expire(struct net
*net
,
5519 const struct sctp_endpoint
*ep
,
5520 const struct sctp_association
*asoc
,
5521 const sctp_subtype_t type
,
5523 sctp_cmd_seq_t
*commands
)
5525 struct sctp_chunk
*repl
= NULL
;
5526 struct sctp_bind_addr
*bp
;
5527 int attempts
= asoc
->init_err_counter
+ 1;
5529 pr_debug("%s: timer T1 expired (INIT)\n", __func__
);
5531 SCTP_INC_STATS(net
, SCTP_MIB_T1_INIT_EXPIREDS
);
5533 if (attempts
<= asoc
->max_init_attempts
) {
5534 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5535 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5537 return SCTP_DISPOSITION_NOMEM
;
5539 /* Choose transport for INIT. */
5540 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5543 /* Issue a sideeffect to do the needed accounting. */
5544 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5545 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5547 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5549 pr_debug("%s: giving up on INIT, attempts:%d "
5550 "max_init_attempts:%d\n", __func__
, attempts
,
5551 asoc
->max_init_attempts
);
5553 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5554 SCTP_ERROR(ETIMEDOUT
));
5555 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5556 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5557 return SCTP_DISPOSITION_DELETE_TCB
;
5560 return SCTP_DISPOSITION_CONSUME
;
5564 * sctp_sf_t1_cookie_timer_expire
5566 * Section: 4 Note: 2
5571 * RFC 2960 Section 4 Notes
5572 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5573 * COOKIE ECHO and re-start the T1-cookie timer without changing
5574 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5575 * After that, the endpoint MUST abort the initialization process and
5576 * report the error to SCTP user.
5582 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(struct net
*net
,
5583 const struct sctp_endpoint
*ep
,
5584 const struct sctp_association
*asoc
,
5585 const sctp_subtype_t type
,
5587 sctp_cmd_seq_t
*commands
)
5589 struct sctp_chunk
*repl
= NULL
;
5590 int attempts
= asoc
->init_err_counter
+ 1;
5592 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__
);
5594 SCTP_INC_STATS(net
, SCTP_MIB_T1_COOKIE_EXPIREDS
);
5596 if (attempts
<= asoc
->max_init_attempts
) {
5597 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5599 return SCTP_DISPOSITION_NOMEM
;
5601 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5603 /* Issue a sideeffect to do the needed accounting. */
5604 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5605 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5607 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5609 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5610 SCTP_ERROR(ETIMEDOUT
));
5611 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5612 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5613 return SCTP_DISPOSITION_DELETE_TCB
;
5616 return SCTP_DISPOSITION_CONSUME
;
5619 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5620 * with the updated last sequential TSN received from its peer.
5622 * An endpoint should limit the number of retransmissions of the
5623 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5624 * If this threshold is exceeded the endpoint should destroy the TCB and
5625 * MUST report the peer endpoint unreachable to the upper layer (and
5626 * thus the association enters the CLOSED state). The reception of any
5627 * packet from its peer (i.e. as the peer sends all of its queued DATA
5628 * chunks) should clear the endpoint's retransmission count and restart
5629 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5630 * all of its queued DATA chunks that have not yet been sent.
5632 sctp_disposition_t
sctp_sf_t2_timer_expire(struct net
*net
,
5633 const struct sctp_endpoint
*ep
,
5634 const struct sctp_association
*asoc
,
5635 const sctp_subtype_t type
,
5637 sctp_cmd_seq_t
*commands
)
5639 struct sctp_chunk
*reply
= NULL
;
5641 pr_debug("%s: timer T2 expired\n", __func__
);
5643 SCTP_INC_STATS(net
, SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5645 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5647 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5648 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5649 SCTP_ERROR(ETIMEDOUT
));
5650 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5651 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5652 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5653 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5654 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5655 return SCTP_DISPOSITION_DELETE_TCB
;
5658 switch (asoc
->state
) {
5659 case SCTP_STATE_SHUTDOWN_SENT
:
5660 reply
= sctp_make_shutdown(asoc
, NULL
);
5663 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5664 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5675 /* Do some failure management (Section 8.2).
5676 * If we remove the transport an SHUTDOWN was last sent to, don't
5677 * do failure management.
5679 if (asoc
->shutdown_last_sent_to
)
5680 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5681 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5683 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5684 * the T2-shutdown timer.
5686 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5688 /* Restart the T2-shutdown timer. */
5689 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5690 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5691 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5692 return SCTP_DISPOSITION_CONSUME
;
5695 return SCTP_DISPOSITION_NOMEM
;
5699 * ADDIP Section 4.1 ASCONF CHunk Procedures
5700 * If the T4 RTO timer expires the endpoint should do B1 to B5
5702 sctp_disposition_t
sctp_sf_t4_timer_expire(
5704 const struct sctp_endpoint
*ep
,
5705 const struct sctp_association
*asoc
,
5706 const sctp_subtype_t type
,
5708 sctp_cmd_seq_t
*commands
)
5710 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5711 struct sctp_transport
*transport
= chunk
->transport
;
5713 SCTP_INC_STATS(net
, SCTP_MIB_T4_RTO_EXPIREDS
);
5715 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5716 * detection on the appropriate destination address as defined in
5717 * RFC2960 [5] section 8.1 and 8.2.
5720 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5721 SCTP_TRANSPORT(transport
));
5723 /* Reconfig T4 timer and transport. */
5724 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5726 /* ADDIP 4.1 B2) Increment the association error counters and perform
5727 * endpoint failure detection on the association as defined in
5728 * RFC2960 [5] section 8.1 and 8.2.
5729 * association error counter is incremented in SCTP_CMD_STRIKE.
5731 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5732 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5733 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5734 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5735 SCTP_ERROR(ETIMEDOUT
));
5736 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5737 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5738 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5739 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5740 return SCTP_DISPOSITION_ABORT
;
5743 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5744 * the ASCONF chunk was sent by doubling the RTO timer value.
5745 * This is done in SCTP_CMD_STRIKE.
5748 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5749 * choose an alternate destination address (please refer to RFC2960
5750 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5751 * chunk, it MUST be the same (including its serial number) as the last
5754 sctp_chunk_hold(asoc
->addip_last_asconf
);
5755 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5756 SCTP_CHUNK(asoc
->addip_last_asconf
));
5758 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5759 * destination is selected, then the RTO used will be that of the new
5760 * destination address.
5762 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5763 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5765 return SCTP_DISPOSITION_CONSUME
;
5768 /* sctpimpguide-05 Section 2.12.2
5769 * The sender of the SHUTDOWN MAY also start an overall guard timer
5770 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5771 * At the expiration of this timer the sender SHOULD abort the association
5772 * by sending an ABORT chunk.
5774 sctp_disposition_t
sctp_sf_t5_timer_expire(struct net
*net
,
5775 const struct sctp_endpoint
*ep
,
5776 const struct sctp_association
*asoc
,
5777 const sctp_subtype_t type
,
5779 sctp_cmd_seq_t
*commands
)
5781 struct sctp_chunk
*reply
= NULL
;
5783 pr_debug("%s: timer T5 expired\n", __func__
);
5785 SCTP_INC_STATS(net
, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5787 reply
= sctp_make_abort(asoc
, NULL
, 0);
5791 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5792 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5793 SCTP_ERROR(ETIMEDOUT
));
5794 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5795 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5797 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5798 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5800 return SCTP_DISPOSITION_DELETE_TCB
;
5802 return SCTP_DISPOSITION_NOMEM
;
5805 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5806 * the association is automatically closed by starting the shutdown process.
5807 * The work that needs to be done is same as when SHUTDOWN is initiated by
5808 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5810 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5812 const struct sctp_endpoint
*ep
,
5813 const struct sctp_association
*asoc
,
5814 const sctp_subtype_t type
,
5816 sctp_cmd_seq_t
*commands
)
5820 SCTP_INC_STATS(net
, SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5822 /* From 9.2 Shutdown of an Association
5823 * Upon receipt of the SHUTDOWN primitive from its upper
5824 * layer, the endpoint enters SHUTDOWN-PENDING state and
5825 * remains there until all outstanding data has been
5826 * acknowledged by its peer. The endpoint accepts no new data
5827 * from its upper layer, but retransmits data to the far end
5828 * if necessary to fill gaps.
5830 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5831 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5833 disposition
= SCTP_DISPOSITION_CONSUME
;
5834 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5835 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
5841 /*****************************************************************************
5842 * These are sa state functions which could apply to all types of events.
5843 ****************************************************************************/
5846 * This table entry is not implemented.
5849 * (endpoint, asoc, chunk)
5851 * The return value is the disposition of the chunk.
5853 sctp_disposition_t
sctp_sf_not_impl(struct net
*net
,
5854 const struct sctp_endpoint
*ep
,
5855 const struct sctp_association
*asoc
,
5856 const sctp_subtype_t type
,
5858 sctp_cmd_seq_t
*commands
)
5860 return SCTP_DISPOSITION_NOT_IMPL
;
5864 * This table entry represents a bug.
5867 * (endpoint, asoc, chunk)
5869 * The return value is the disposition of the chunk.
5871 sctp_disposition_t
sctp_sf_bug(struct net
*net
,
5872 const struct sctp_endpoint
*ep
,
5873 const struct sctp_association
*asoc
,
5874 const sctp_subtype_t type
,
5876 sctp_cmd_seq_t
*commands
)
5878 return SCTP_DISPOSITION_BUG
;
5882 * This table entry represents the firing of a timer in the wrong state.
5883 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5884 * when the association is in the wrong state. This event should
5885 * be ignored, so as to prevent any rearming of the timer.
5888 * (endpoint, asoc, chunk)
5890 * The return value is the disposition of the chunk.
5892 sctp_disposition_t
sctp_sf_timer_ignore(struct net
*net
,
5893 const struct sctp_endpoint
*ep
,
5894 const struct sctp_association
*asoc
,
5895 const sctp_subtype_t type
,
5897 sctp_cmd_seq_t
*commands
)
5899 pr_debug("%s: timer %d ignored\n", __func__
, type
.chunk
);
5901 return SCTP_DISPOSITION_CONSUME
;
5904 /********************************************************************
5905 * 2nd Level Abstractions
5906 ********************************************************************/
5908 /* Pull the SACK chunk based on the SACK header. */
5909 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5911 struct sctp_sackhdr
*sack
;
5916 /* Protect ourselves from reading too far into
5917 * the skb from a bogus sender.
5919 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5921 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5922 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5923 len
= sizeof(struct sctp_sackhdr
);
5924 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5925 if (len
> chunk
->skb
->len
)
5928 skb_pull(chunk
->skb
, len
);
5933 /* Create an ABORT packet to be sent as a response, with the specified
5936 static struct sctp_packet
*sctp_abort_pkt_new(struct net
*net
,
5937 const struct sctp_endpoint
*ep
,
5938 const struct sctp_association
*asoc
,
5939 struct sctp_chunk
*chunk
,
5940 const void *payload
,
5943 struct sctp_packet
*packet
;
5944 struct sctp_chunk
*abort
;
5946 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
5950 * The T bit will be set if the asoc is NULL.
5952 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5954 sctp_ootb_pkt_free(packet
);
5958 /* Reflect vtag if T-Bit is set */
5959 if (sctp_test_T_bit(abort
))
5960 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5962 /* Add specified error causes, i.e., payload, to the
5965 sctp_addto_chunk(abort
, paylen
, payload
);
5967 /* Set the skb to the belonging sock for accounting. */
5968 abort
->skb
->sk
= ep
->base
.sk
;
5970 sctp_packet_append_chunk(packet
, abort
);
5977 /* Allocate a packet for responding in the OOTB conditions. */
5978 static struct sctp_packet
*sctp_ootb_pkt_new(struct net
*net
,
5979 const struct sctp_association
*asoc
,
5980 const struct sctp_chunk
*chunk
)
5982 struct sctp_packet
*packet
;
5983 struct sctp_transport
*transport
;
5988 /* Get the source and destination port from the inbound packet. */
5989 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5990 dport
= ntohs(chunk
->sctp_hdr
->source
);
5992 /* The V-tag is going to be the same as the inbound packet if no
5993 * association exists, otherwise, use the peer's vtag.
5996 /* Special case the INIT-ACK as there is no peer's vtag
5999 switch (chunk
->chunk_hdr
->type
) {
6000 case SCTP_CID_INIT_ACK
:
6002 sctp_initack_chunk_t
*initack
;
6004 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
6005 vtag
= ntohl(initack
->init_hdr
.init_tag
);
6009 vtag
= asoc
->peer
.i
.init_tag
;
6013 /* Special case the INIT and stale COOKIE_ECHO as there is no
6016 switch (chunk
->chunk_hdr
->type
) {
6019 sctp_init_chunk_t
*init
;
6021 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
6022 vtag
= ntohl(init
->init_hdr
.init_tag
);
6026 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
6031 /* Make a transport for the bucket, Eliza... */
6032 transport
= sctp_transport_new(net
, sctp_source(chunk
), GFP_ATOMIC
);
6036 /* Cache a route for the transport with the chunk's destination as
6037 * the source address.
6039 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
6040 sctp_sk(net
->sctp
.ctl_sock
));
6042 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
6043 packet
= sctp_packet_config(packet
, vtag
, 0);
6051 /* Free the packet allocated earlier for responding in the OOTB condition. */
6052 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
6054 sctp_transport_free(packet
->transport
);
6057 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6058 static void sctp_send_stale_cookie_err(struct net
*net
,
6059 const struct sctp_endpoint
*ep
,
6060 const struct sctp_association
*asoc
,
6061 const struct sctp_chunk
*chunk
,
6062 sctp_cmd_seq_t
*commands
,
6063 struct sctp_chunk
*err_chunk
)
6065 struct sctp_packet
*packet
;
6068 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
6070 struct sctp_signed_cookie
*cookie
;
6072 /* Override the OOTB vtag from the cookie. */
6073 cookie
= chunk
->subh
.cookie_hdr
;
6074 packet
->vtag
= cookie
->c
.peer_vtag
;
6076 /* Set the skb to the belonging sock for accounting. */
6077 err_chunk
->skb
->sk
= ep
->base
.sk
;
6078 sctp_packet_append_chunk(packet
, err_chunk
);
6079 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
6080 SCTP_PACKET(packet
));
6081 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
6083 sctp_chunk_free (err_chunk
);
6088 /* Process a data chunk */
6089 static int sctp_eat_data(const struct sctp_association
*asoc
,
6090 struct sctp_chunk
*chunk
,
6091 sctp_cmd_seq_t
*commands
)
6093 sctp_datahdr_t
*data_hdr
;
6094 struct sctp_chunk
*err
;
6096 sctp_verb_t deliver
;
6099 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
6100 struct sock
*sk
= asoc
->base
.sk
;
6101 struct net
*net
= sock_net(sk
);
6106 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
6107 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
6109 tsn
= ntohl(data_hdr
->tsn
);
6110 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
6112 /* ASSERT: Now skb->data is really the user data. */
6114 /* Process ECN based congestion.
6116 * Since the chunk structure is reused for all chunks within
6117 * a packet, we use ecn_ce_done to track if we've already
6118 * done CE processing for this packet.
6120 * We need to do ECN processing even if we plan to discard the
6124 if (!chunk
->ecn_ce_done
) {
6126 chunk
->ecn_ce_done
= 1;
6128 af
= sctp_get_af_specific(
6129 ipver2af(ip_hdr(chunk
->skb
)->version
));
6131 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
6132 /* Do real work as sideffect. */
6133 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
6138 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
6140 /* The TSN is too high--silently discard the chunk and
6141 * count on it getting retransmitted later.
6144 chunk
->asoc
->stats
.outofseqtsns
++;
6145 return SCTP_IERROR_HIGH_TSN
;
6146 } else if (tmp
> 0) {
6147 /* This is a duplicate. Record it. */
6148 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
6149 return SCTP_IERROR_DUP_TSN
;
6152 /* This is a new TSN. */
6154 /* Discard if there is no room in the receive window.
6155 * Actually, allow a little bit of overflow (up to a MTU).
6157 datalen
= ntohs(chunk
->chunk_hdr
->length
);
6158 datalen
-= sizeof(sctp_data_chunk_t
);
6160 deliver
= SCTP_CMD_CHUNK_ULP
;
6162 /* Think about partial delivery. */
6163 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
6165 /* Even if we don't accept this chunk there is
6168 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
6171 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6172 * seems a bit troublesome in that frag_point varies based on
6173 * PMTU. In cases, such as loopback, this might be a rather
6176 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
6177 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
6179 /* If this is the next TSN, consider reneging to make
6180 * room. Note: Playing nice with a confused sender. A
6181 * malicious sender can still eat up all our buffer
6182 * space and in the future we may want to detect and
6183 * do more drastic reneging.
6185 if (sctp_tsnmap_has_gap(map
) &&
6186 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6187 pr_debug("%s: reneging for tsn:%u\n", __func__
, tsn
);
6188 deliver
= SCTP_CMD_RENEGE
;
6190 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6191 __func__
, tsn
, datalen
, asoc
->rwnd
);
6193 return SCTP_IERROR_IGNORE_TSN
;
6198 * Also try to renege to limit our memory usage in the event that
6199 * we are under memory pressure
6200 * If we can't renege, don't worry about it, the sk_rmem_schedule
6201 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6202 * memory usage too much
6204 if (*sk
->sk_prot_creator
->memory_pressure
) {
6205 if (sctp_tsnmap_has_gap(map
) &&
6206 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6207 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6209 deliver
= SCTP_CMD_RENEGE
;
6214 * Section 3.3.10.9 No User Data (9)
6218 * No User Data: This error cause is returned to the originator of a
6219 * DATA chunk if a received DATA chunk has no user data.
6221 if (unlikely(0 == datalen
)) {
6222 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6224 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6227 /* We are going to ABORT, so we might as well stop
6228 * processing the rest of the chunks in the packet.
6230 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
6231 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6232 SCTP_ERROR(ECONNABORTED
));
6233 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6234 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6235 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
6236 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
6237 return SCTP_IERROR_NO_DATA
;
6240 chunk
->data_accepted
= 1;
6242 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6243 * if we renege and the chunk arrives again.
6245 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
) {
6246 SCTP_INC_STATS(net
, SCTP_MIB_INUNORDERCHUNKS
);
6248 chunk
->asoc
->stats
.iuodchunks
++;
6250 SCTP_INC_STATS(net
, SCTP_MIB_INORDERCHUNKS
);
6252 chunk
->asoc
->stats
.iodchunks
++;
6256 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6258 * If an endpoint receive a DATA chunk with an invalid stream
6259 * identifier, it shall acknowledge the reception of the DATA chunk
6260 * following the normal procedure, immediately send an ERROR chunk
6261 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6262 * and discard the DATA chunk.
6264 sid
= ntohs(data_hdr
->stream
);
6265 if (sid
>= asoc
->c
.sinit_max_instreams
) {
6266 /* Mark tsn as received even though we drop it */
6267 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6269 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6271 sizeof(data_hdr
->stream
),
6274 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6276 return SCTP_IERROR_BAD_STREAM
;
6279 /* Check to see if the SSN is possible for this TSN.
6280 * The biggest gap we can record is 4K wide. Since SSNs wrap
6281 * at an unsigned short, there is no way that an SSN can
6282 * wrap and for a valid TSN. We can simply check if the current
6283 * SSN is smaller then the next expected one. If it is, it wrapped
6286 ssn
= ntohs(data_hdr
->ssn
);
6287 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(&asoc
->ssnmap
->in
, sid
))) {
6288 return SCTP_IERROR_PROTO_VIOLATION
;
6291 /* Send the data up to the user. Note: Schedule the
6292 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6293 * chunk needs the updated rwnd.
6295 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6297 return SCTP_IERROR_NO_ERROR
;