1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
8 * This is part of the SCTP Linux Kernel Implementation.
10 * These are the state functions for the state machine.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Mathew Kotowsky <kotowsky@sctp.org>
36 * Sridhar Samudrala <samudrala@us.ibm.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Kevin Gao <kevin.gao@intel.com>
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 #include <linux/types.h>
49 #include <linux/kernel.h>
51 #include <linux/ipv6.h>
52 #include <linux/net.h>
53 #include <linux/inet.h>
54 #include <linux/slab.h>
56 #include <net/inet_ecn.h>
57 #include <linux/skbuff.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60 #include <net/sctp/structs.h>
62 static struct sctp_packet
*sctp_abort_pkt_new(struct net
*net
,
63 const struct sctp_endpoint
*ep
,
64 const struct sctp_association
*asoc
,
65 struct sctp_chunk
*chunk
,
68 static int sctp_eat_data(const struct sctp_association
*asoc
,
69 struct sctp_chunk
*chunk
,
70 sctp_cmd_seq_t
*commands
);
71 static struct sctp_packet
*sctp_ootb_pkt_new(struct net
*net
,
72 const struct sctp_association
*asoc
,
73 const struct sctp_chunk
*chunk
);
74 static void sctp_send_stale_cookie_err(struct net
*net
,
75 const struct sctp_endpoint
*ep
,
76 const struct sctp_association
*asoc
,
77 const struct sctp_chunk
*chunk
,
78 sctp_cmd_seq_t
*commands
,
79 struct sctp_chunk
*err_chunk
);
80 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(struct net
*net
,
81 const struct sctp_endpoint
*ep
,
82 const struct sctp_association
*asoc
,
83 const sctp_subtype_t type
,
85 sctp_cmd_seq_t
*commands
);
86 static sctp_disposition_t
sctp_sf_shut_8_4_5(struct net
*net
,
87 const struct sctp_endpoint
*ep
,
88 const struct sctp_association
*asoc
,
89 const sctp_subtype_t type
,
91 sctp_cmd_seq_t
*commands
);
92 static sctp_disposition_t
sctp_sf_tabort_8_4_8(struct net
*net
,
93 const struct sctp_endpoint
*ep
,
94 const struct sctp_association
*asoc
,
95 const sctp_subtype_t type
,
97 sctp_cmd_seq_t
*commands
);
98 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
100 static sctp_disposition_t
sctp_stop_t1_and_abort(struct net
*net
,
101 sctp_cmd_seq_t
*commands
,
102 __be16 error
, int sk_err
,
103 const struct sctp_association
*asoc
,
104 struct sctp_transport
*transport
);
106 static sctp_disposition_t
sctp_sf_abort_violation(
108 const struct sctp_endpoint
*ep
,
109 const struct sctp_association
*asoc
,
111 sctp_cmd_seq_t
*commands
,
113 const size_t paylen
);
115 static sctp_disposition_t
sctp_sf_violation_chunklen(
117 const struct sctp_endpoint
*ep
,
118 const struct sctp_association
*asoc
,
119 const sctp_subtype_t type
,
121 sctp_cmd_seq_t
*commands
);
123 static sctp_disposition_t
sctp_sf_violation_paramlen(
125 const struct sctp_endpoint
*ep
,
126 const struct sctp_association
*asoc
,
127 const sctp_subtype_t type
,
128 void *arg
, void *ext
,
129 sctp_cmd_seq_t
*commands
);
131 static sctp_disposition_t
sctp_sf_violation_ctsn(
133 const struct sctp_endpoint
*ep
,
134 const struct sctp_association
*asoc
,
135 const sctp_subtype_t type
,
137 sctp_cmd_seq_t
*commands
);
139 static sctp_disposition_t
sctp_sf_violation_chunk(
141 const struct sctp_endpoint
*ep
,
142 const struct sctp_association
*asoc
,
143 const sctp_subtype_t type
,
145 sctp_cmd_seq_t
*commands
);
147 static sctp_ierror_t
sctp_sf_authenticate(struct net
*net
,
148 const struct sctp_endpoint
*ep
,
149 const struct sctp_association
*asoc
,
150 const sctp_subtype_t type
,
151 struct sctp_chunk
*chunk
);
153 static sctp_disposition_t
__sctp_sf_do_9_1_abort(struct net
*net
,
154 const struct sctp_endpoint
*ep
,
155 const struct sctp_association
*asoc
,
156 const sctp_subtype_t type
,
158 sctp_cmd_seq_t
*commands
);
160 /* Small helper function that checks if the chunk length
161 * is of the appropriate length. The 'required_length' argument
162 * is set to be the size of a specific chunk we are testing.
163 * Return Values: true = Valid length
164 * false = Invalid length
168 sctp_chunk_length_valid(struct sctp_chunk
*chunk
, __u16 required_length
)
170 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
172 /* Previously already marked? */
173 if (unlikely(chunk
->pdiscard
))
175 if (unlikely(chunk_length
< required_length
))
181 /**********************************************************
182 * These are the state functions for handling chunk events.
183 **********************************************************/
186 * Process the final SHUTDOWN COMPLETE.
188 * Section: 4 (C) (diagram), 9.2
189 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
190 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
191 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
192 * should stop the T2-shutdown timer and remove all knowledge of the
193 * association (and thus the association enters the CLOSED state).
195 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
196 * C) Rules for packet carrying SHUTDOWN COMPLETE:
198 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
199 * if the Verification Tag field of the packet matches its own tag and
200 * the T bit is not set
202 * it is set to its peer's tag and the T bit is set in the Chunk
204 * Otherwise, the receiver MUST silently discard the packet
205 * and take no further action. An endpoint MUST ignore the
206 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
209 * (endpoint, asoc, chunk)
212 * (asoc, reply_msg, msg_up, timers, counters)
214 * The return value is the disposition of the chunk.
216 sctp_disposition_t
sctp_sf_do_4_C(struct net
*net
,
217 const struct sctp_endpoint
*ep
,
218 const struct sctp_association
*asoc
,
219 const sctp_subtype_t type
,
221 sctp_cmd_seq_t
*commands
)
223 struct sctp_chunk
*chunk
= arg
;
224 struct sctp_ulpevent
*ev
;
226 if (!sctp_vtag_verify_either(chunk
, asoc
))
227 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
229 /* RFC 2960 6.10 Bundling
231 * An endpoint MUST NOT bundle INIT, INIT ACK or
232 * SHUTDOWN COMPLETE with any other chunks.
234 if (!chunk
->singleton
)
235 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
237 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
238 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
239 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
242 /* RFC 2960 10.2 SCTP-to-ULP
244 * H) SHUTDOWN COMPLETE notification
246 * When SCTP completes the shutdown procedures (section 9.2) this
247 * notification is passed to the upper layer.
249 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
250 0, 0, 0, NULL
, GFP_ATOMIC
);
252 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
255 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
256 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
257 * not the chunk should be discarded. If the endpoint is in
258 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
259 * T2-shutdown timer and remove all knowledge of the
260 * association (and thus the association enters the CLOSED
263 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
264 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
266 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
267 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
269 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
270 SCTP_STATE(SCTP_STATE_CLOSED
));
272 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
273 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
275 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
277 return SCTP_DISPOSITION_DELETE_TCB
;
281 * Respond to a normal INIT chunk.
282 * We are the side that is being asked for an association.
284 * Section: 5.1 Normal Establishment of an Association, B
285 * B) "Z" shall respond immediately with an INIT ACK chunk. The
286 * destination IP address of the INIT ACK MUST be set to the source
287 * IP address of the INIT to which this INIT ACK is responding. In
288 * the response, besides filling in other parameters, "Z" must set the
289 * Verification Tag field to Tag_A, and also provide its own
290 * Verification Tag (Tag_Z) in the Initiate Tag field.
292 * Verification Tag: Must be 0.
295 * (endpoint, asoc, chunk)
298 * (asoc, reply_msg, msg_up, timers, counters)
300 * The return value is the disposition of the chunk.
302 sctp_disposition_t
sctp_sf_do_5_1B_init(struct net
*net
,
303 const struct sctp_endpoint
*ep
,
304 const struct sctp_association
*asoc
,
305 const sctp_subtype_t type
,
307 sctp_cmd_seq_t
*commands
)
309 struct sctp_chunk
*chunk
= arg
;
310 struct sctp_chunk
*repl
;
311 struct sctp_association
*new_asoc
;
312 struct sctp_chunk
*err_chunk
;
313 struct sctp_packet
*packet
;
314 sctp_unrecognized_param_t
*unk_param
;
318 * An endpoint MUST NOT bundle INIT, INIT ACK or
319 * SHUTDOWN COMPLETE with any other chunks.
322 * Furthermore, we require that the receiver of an INIT chunk MUST
323 * enforce these rules by silently discarding an arriving packet
324 * with an INIT chunk that is bundled with other chunks.
326 if (!chunk
->singleton
)
327 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
329 /* If the packet is an OOTB packet which is temporarily on the
330 * control endpoint, respond with an ABORT.
332 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
333 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
334 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
337 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
340 if (chunk
->sctp_hdr
->vtag
!= 0)
341 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
343 /* Make sure that the INIT chunk has a valid length.
344 * Normally, this would cause an ABORT with a Protocol Violation
345 * error, but since we don't have an association, we'll
346 * just discard the packet.
348 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
349 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
351 /* If the INIT is coming toward a closing socket, we'll send back
352 * and ABORT. Essentially, this catches the race of INIT being
353 * backloged to the socket at the same time as the user isses close().
354 * Since the socket and all its associations are going away, we
355 * can treat this OOTB
357 if (sctp_sstate(ep
->base
.sk
, CLOSING
))
358 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
360 /* Verify the INIT chunk before processing it. */
362 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
363 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
365 /* This chunk contains fatal error. It is to be discarded.
366 * Send an ABORT, with causes if there is any.
369 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
370 (__u8
*)(err_chunk
->chunk_hdr
) +
371 sizeof(sctp_chunkhdr_t
),
372 ntohs(err_chunk
->chunk_hdr
->length
) -
373 sizeof(sctp_chunkhdr_t
));
375 sctp_chunk_free(err_chunk
);
378 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
379 SCTP_PACKET(packet
));
380 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
381 return SCTP_DISPOSITION_CONSUME
;
383 return SCTP_DISPOSITION_NOMEM
;
386 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
391 /* Grab the INIT header. */
392 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
394 /* Tag the variable length parameters. */
395 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
397 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
401 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
402 sctp_scope(sctp_source(chunk
)),
406 /* The call, sctp_process_init(), can fail on memory allocation. */
407 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
408 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
412 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
414 /* If there are errors need to be reported for unknown parameters,
415 * make sure to reserve enough room in the INIT ACK for them.
419 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
420 sizeof(sctp_chunkhdr_t
);
422 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
426 /* If there are errors need to be reported for unknown parameters,
427 * include them in the outgoing INIT ACK as "Unrecognized parameter"
431 /* Get the "Unrecognized parameter" parameter(s) out of the
432 * ERROR chunk generated by sctp_verify_init(). Since the
433 * error cause code for "unknown parameter" and the
434 * "Unrecognized parameter" type is the same, we can
435 * construct the parameters in INIT ACK by copying the
438 unk_param
= (sctp_unrecognized_param_t
*)
439 ((__u8
*)(err_chunk
->chunk_hdr
) +
440 sizeof(sctp_chunkhdr_t
));
441 /* Replace the cause code with the "Unrecognized parameter"
444 sctp_addto_chunk(repl
, len
, unk_param
);
445 sctp_chunk_free(err_chunk
);
448 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
450 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
453 * Note: After sending out INIT ACK with the State Cookie parameter,
454 * "Z" MUST NOT allocate any resources, nor keep any states for the
455 * new association. Otherwise, "Z" will be vulnerable to resource
458 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
460 return SCTP_DISPOSITION_DELETE_TCB
;
463 sctp_association_free(new_asoc
);
466 sctp_chunk_free(err_chunk
);
467 return SCTP_DISPOSITION_NOMEM
;
471 * Respond to a normal INIT ACK chunk.
472 * We are the side that is initiating the association.
474 * Section: 5.1 Normal Establishment of an Association, C
475 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
476 * timer and leave COOKIE-WAIT state. "A" shall then send the State
477 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
478 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
480 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
481 * DATA chunks, but it MUST be the first chunk in the packet and
482 * until the COOKIE ACK is returned the sender MUST NOT send any
483 * other packets to the peer.
485 * Verification Tag: 3.3.3
486 * If the value of the Initiate Tag in a received INIT ACK chunk is
487 * found to be 0, the receiver MUST treat it as an error and close the
488 * association by transmitting an ABORT.
491 * (endpoint, asoc, chunk)
494 * (asoc, reply_msg, msg_up, timers, counters)
496 * The return value is the disposition of the chunk.
498 sctp_disposition_t
sctp_sf_do_5_1C_ack(struct net
*net
,
499 const struct sctp_endpoint
*ep
,
500 const struct sctp_association
*asoc
,
501 const sctp_subtype_t type
,
503 sctp_cmd_seq_t
*commands
)
505 struct sctp_chunk
*chunk
= arg
;
506 sctp_init_chunk_t
*initchunk
;
507 struct sctp_chunk
*err_chunk
;
508 struct sctp_packet
*packet
;
510 if (!sctp_vtag_verify(chunk
, asoc
))
511 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
514 * An endpoint MUST NOT bundle INIT, INIT ACK or
515 * SHUTDOWN COMPLETE with any other chunks.
517 if (!chunk
->singleton
)
518 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
520 /* Make sure that the INIT-ACK chunk has a valid length */
521 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
522 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
524 /* Grab the INIT header. */
525 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
527 /* Verify the INIT chunk before processing it. */
529 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
530 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
533 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
535 /* This chunk contains fatal error. It is to be discarded.
536 * Send an ABORT, with causes. If there are no causes,
537 * then there wasn't enough memory. Just terminate
541 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
542 (__u8
*)(err_chunk
->chunk_hdr
) +
543 sizeof(sctp_chunkhdr_t
),
544 ntohs(err_chunk
->chunk_hdr
->length
) -
545 sizeof(sctp_chunkhdr_t
));
547 sctp_chunk_free(err_chunk
);
550 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
551 SCTP_PACKET(packet
));
552 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
553 error
= SCTP_ERROR_INV_PARAM
;
557 /* SCTP-AUTH, Section 6.3:
558 * It should be noted that if the receiver wants to tear
559 * down an association in an authenticated way only, the
560 * handling of malformed packets should not result in
561 * tearing down the association.
563 * This means that if we only want to abort associations
564 * in an authenticated way (i.e AUTH+ABORT), then we
565 * can't destroy this association just because the packet
568 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
569 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
571 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
572 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
,
573 asoc
, chunk
->transport
);
576 /* Tag the variable length parameters. Note that we never
577 * convert the parameters in an INIT chunk.
579 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
581 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
583 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
584 SCTP_PEER_INIT(initchunk
));
586 /* Reset init error count upon receipt of INIT-ACK. */
587 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
589 /* 5.1 C) "A" shall stop the T1-init timer and leave
590 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
591 * timer, and enter the COOKIE-ECHOED state.
593 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
595 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
596 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
597 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
598 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
600 /* SCTP-AUTH: genereate the assocition shared keys so that
601 * we can potentially signe the COOKIE-ECHO.
603 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
605 /* 5.1 C) "A" shall then send the State Cookie received in the
606 * INIT ACK chunk in a COOKIE ECHO chunk, ...
608 /* If there is any errors to report, send the ERROR chunk generated
609 * for unknown parameters as well.
611 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
612 SCTP_CHUNK(err_chunk
));
614 return SCTP_DISPOSITION_CONSUME
;
618 * Respond to a normal COOKIE ECHO chunk.
619 * We are the side that is being asked for an association.
621 * Section: 5.1 Normal Establishment of an Association, D
622 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
623 * with a COOKIE ACK chunk after building a TCB and moving to
624 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
625 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
626 * chunk MUST be the first chunk in the packet.
628 * IMPLEMENTATION NOTE: An implementation may choose to send the
629 * Communication Up notification to the SCTP user upon reception
630 * of a valid COOKIE ECHO chunk.
632 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
633 * D) Rules for packet carrying a COOKIE ECHO
635 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
636 * Initial Tag received in the INIT ACK.
638 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
641 * (endpoint, asoc, chunk)
644 * (asoc, reply_msg, msg_up, timers, counters)
646 * The return value is the disposition of the chunk.
648 sctp_disposition_t
sctp_sf_do_5_1D_ce(struct net
*net
,
649 const struct sctp_endpoint
*ep
,
650 const struct sctp_association
*asoc
,
651 const sctp_subtype_t type
, void *arg
,
652 sctp_cmd_seq_t
*commands
)
654 struct sctp_chunk
*chunk
= arg
;
655 struct sctp_association
*new_asoc
;
656 sctp_init_chunk_t
*peer_init
;
657 struct sctp_chunk
*repl
;
658 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
660 struct sctp_chunk
*err_chk_p
;
663 /* If the packet is an OOTB packet which is temporarily on the
664 * control endpoint, respond with an ABORT.
666 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
667 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
668 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
671 /* Make sure that the COOKIE_ECHO chunk has a valid length.
672 * In this case, we check that we have enough for at least a
673 * chunk header. More detailed verification is done
674 * in sctp_unpack_cookie().
676 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
677 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
679 /* If the endpoint is not listening or if the number of associations
680 * on the TCP-style socket exceed the max backlog, respond with an
684 if (!sctp_sstate(sk
, LISTENING
) ||
685 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
686 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
688 /* "Decode" the chunk. We have no optional parameters so we
691 chunk
->subh
.cookie_hdr
=
692 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
693 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
694 sizeof(sctp_chunkhdr_t
)))
697 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
698 * "Z" will reply with a COOKIE ACK chunk after building a TCB
699 * and moving to the ESTABLISHED state.
701 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
705 * If the re-build failed, what is the proper error path
708 * [We should abort the association. --piggy]
711 /* FIXME: Several errors are possible. A bad cookie should
712 * be silently discarded, but think about logging it too.
715 case -SCTP_IERROR_NOMEM
:
718 case -SCTP_IERROR_STALE_COOKIE
:
719 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
721 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
723 case -SCTP_IERROR_BAD_SIG
:
725 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
730 /* Delay state machine commands until later.
732 * Re-build the bind address for the association is done in
733 * the sctp_unpack_cookie() already.
735 /* This is a brand-new association, so these are not yet side
736 * effects--it is safe to run them here.
738 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
740 if (!sctp_process_init(new_asoc
, chunk
,
741 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
742 peer_init
, GFP_ATOMIC
))
745 /* SCTP-AUTH: Now that we've populate required fields in
746 * sctp_process_init, set up the assocaition shared keys as
747 * necessary so that we can potentially authenticate the ACK
749 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
753 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
754 * is supposed to be authenticated and we have to do delayed
755 * authentication. We've just recreated the association using
756 * the information in the cookie and now it's much easier to
757 * do the authentication.
759 if (chunk
->auth_chunk
) {
760 struct sctp_chunk auth
;
763 /* Make sure that we and the peer are AUTH capable */
764 if (!net
->sctp
.auth_enable
|| !new_asoc
->peer
.auth_capable
) {
765 sctp_association_free(new_asoc
);
766 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
769 /* set-up our fake chunk so that we can process it */
770 auth
.skb
= chunk
->auth_chunk
;
771 auth
.asoc
= chunk
->asoc
;
772 auth
.sctp_hdr
= chunk
->sctp_hdr
;
773 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
774 sizeof(sctp_chunkhdr_t
));
775 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
776 auth
.transport
= chunk
->transport
;
778 ret
= sctp_sf_authenticate(net
, ep
, new_asoc
, type
, &auth
);
779 if (ret
!= SCTP_IERROR_NO_ERROR
) {
780 sctp_association_free(new_asoc
);
781 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
785 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
789 /* RFC 2960 5.1 Normal Establishment of an Association
791 * D) IMPLEMENTATION NOTE: An implementation may choose to
792 * send the Communication Up notification to the SCTP user
793 * upon reception of a valid COOKIE ECHO chunk.
795 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
796 new_asoc
->c
.sinit_num_ostreams
,
797 new_asoc
->c
.sinit_max_instreams
,
802 /* Sockets API Draft Section 5.3.1.6
803 * When a peer sends a Adaptation Layer Indication parameter , SCTP
804 * delivers this notification to inform the application that of the
805 * peers requested adaptation layer.
807 if (new_asoc
->peer
.adaptation_ind
) {
808 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
814 /* Add all the state machine commands now since we've created
815 * everything. This way we don't introduce memory corruptions
816 * during side-effect processing and correclty count established
819 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
820 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
821 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
822 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
823 SCTP_INC_STATS(net
, SCTP_MIB_PASSIVEESTABS
);
824 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
826 if (new_asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
827 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
828 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
830 /* This will send the COOKIE ACK */
831 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
833 /* Queue the ASSOC_CHANGE event */
834 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
836 /* Send up the Adaptation Layer Indication event */
838 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
839 SCTP_ULPEVENT(ai_ev
));
841 return SCTP_DISPOSITION_CONSUME
;
844 sctp_ulpevent_free(ev
);
846 sctp_chunk_free(repl
);
848 sctp_association_free(new_asoc
);
850 return SCTP_DISPOSITION_NOMEM
;
854 * Respond to a normal COOKIE ACK chunk.
855 * We are the side that is asking for an association.
857 * RFC 2960 5.1 Normal Establishment of an Association
859 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
860 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
861 * timer. It may also notify its ULP about the successful
862 * establishment of the association with a Communication Up
863 * notification (see Section 10).
867 * (endpoint, asoc, chunk)
870 * (asoc, reply_msg, msg_up, timers, counters)
872 * The return value is the disposition of the chunk.
874 sctp_disposition_t
sctp_sf_do_5_1E_ca(struct net
*net
,
875 const struct sctp_endpoint
*ep
,
876 const struct sctp_association
*asoc
,
877 const sctp_subtype_t type
, void *arg
,
878 sctp_cmd_seq_t
*commands
)
880 struct sctp_chunk
*chunk
= arg
;
881 struct sctp_ulpevent
*ev
;
883 if (!sctp_vtag_verify(chunk
, asoc
))
884 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
886 /* Verify that the chunk length for the COOKIE-ACK is OK.
887 * If we don't do this, any bundled chunks may be junked.
889 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
890 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
893 /* Reset init error count upon receipt of COOKIE-ACK,
894 * to avoid problems with the managemement of this
895 * counter in stale cookie situations when a transition back
896 * from the COOKIE-ECHOED state to the COOKIE-WAIT
897 * state is performed.
899 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
901 /* RFC 2960 5.1 Normal Establishment of an Association
903 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
904 * from the COOKIE-ECHOED state to the ESTABLISHED state,
905 * stopping the T1-cookie timer.
907 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
908 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
909 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
910 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
911 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
912 SCTP_INC_STATS(net
, SCTP_MIB_ACTIVEESTABS
);
913 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
914 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
915 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
916 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
918 /* It may also notify its ULP about the successful
919 * establishment of the association with a Communication Up
920 * notification (see Section 10).
922 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
923 0, asoc
->c
.sinit_num_ostreams
,
924 asoc
->c
.sinit_max_instreams
,
930 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
932 /* Sockets API Draft Section 5.3.1.6
933 * When a peer sends a Adaptation Layer Indication parameter , SCTP
934 * delivers this notification to inform the application that of the
935 * peers requested adaptation layer.
937 if (asoc
->peer
.adaptation_ind
) {
938 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
942 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
946 return SCTP_DISPOSITION_CONSUME
;
948 return SCTP_DISPOSITION_NOMEM
;
951 /* Generate and sendout a heartbeat packet. */
952 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
953 const struct sctp_association
*asoc
,
954 const sctp_subtype_t type
,
956 sctp_cmd_seq_t
*commands
)
958 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
959 struct sctp_chunk
*reply
;
961 /* Send a heartbeat to our peer. */
962 reply
= sctp_make_heartbeat(asoc
, transport
);
964 return SCTP_DISPOSITION_NOMEM
;
966 /* Set rto_pending indicating that an RTT measurement
967 * is started with this heartbeat chunk.
969 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
970 SCTP_TRANSPORT(transport
));
972 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
973 return SCTP_DISPOSITION_CONSUME
;
976 /* Generate a HEARTBEAT packet on the given transport. */
977 sctp_disposition_t
sctp_sf_sendbeat_8_3(struct net
*net
,
978 const struct sctp_endpoint
*ep
,
979 const struct sctp_association
*asoc
,
980 const sctp_subtype_t type
,
982 sctp_cmd_seq_t
*commands
)
984 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
986 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
987 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
988 SCTP_ERROR(ETIMEDOUT
));
989 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
990 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
991 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
992 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
993 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
994 return SCTP_DISPOSITION_DELETE_TCB
;
998 * The Sender-specific Heartbeat Info field should normally include
999 * information about the sender's current time when this HEARTBEAT
1000 * chunk is sent and the destination transport address to which this
1001 * HEARTBEAT is sent (see Section 8.3).
1004 if (transport
->param_flags
& SPP_HB_ENABLE
) {
1005 if (SCTP_DISPOSITION_NOMEM
==
1006 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
1008 return SCTP_DISPOSITION_NOMEM
;
1010 /* Set transport error counter and association error counter
1011 * when sending heartbeat.
1013 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
1014 SCTP_TRANSPORT(transport
));
1016 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1017 SCTP_TRANSPORT(transport
));
1018 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1019 SCTP_TRANSPORT(transport
));
1021 return SCTP_DISPOSITION_CONSUME
;
1024 /* resend asoc strreset_chunk. */
1025 sctp_disposition_t
sctp_sf_send_reconf(struct net
*net
,
1026 const struct sctp_endpoint
*ep
,
1027 const struct sctp_association
*asoc
,
1028 const sctp_subtype_t type
, void *arg
,
1029 sctp_cmd_seq_t
*commands
)
1031 struct sctp_transport
*transport
= arg
;
1033 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
1034 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
1035 SCTP_ERROR(ETIMEDOUT
));
1036 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1037 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
1038 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
1039 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
1040 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
1041 return SCTP_DISPOSITION_DELETE_TCB
;
1044 sctp_chunk_hold(asoc
->strreset_chunk
);
1045 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1046 SCTP_CHUNK(asoc
->strreset_chunk
));
1047 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
1049 return SCTP_DISPOSITION_CONSUME
;
1053 * Process an heartbeat request.
1055 * Section: 8.3 Path Heartbeat
1056 * The receiver of the HEARTBEAT should immediately respond with a
1057 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1058 * from the received HEARTBEAT chunk.
1060 * Verification Tag: 8.5 Verification Tag [Normal verification]
1061 * When receiving an SCTP packet, the endpoint MUST ensure that the
1062 * value in the Verification Tag field of the received SCTP packet
1063 * matches its own Tag. If the received Verification Tag value does not
1064 * match the receiver's own tag value, the receiver shall silently
1065 * discard the packet and shall not process it any further except for
1066 * those cases listed in Section 8.5.1 below.
1069 * (endpoint, asoc, chunk)
1072 * (asoc, reply_msg, msg_up, timers, counters)
1074 * The return value is the disposition of the chunk.
1076 sctp_disposition_t
sctp_sf_beat_8_3(struct net
*net
,
1077 const struct sctp_endpoint
*ep
,
1078 const struct sctp_association
*asoc
,
1079 const sctp_subtype_t type
,
1081 sctp_cmd_seq_t
*commands
)
1083 sctp_paramhdr_t
*param_hdr
;
1084 struct sctp_chunk
*chunk
= arg
;
1085 struct sctp_chunk
*reply
;
1088 if (!sctp_vtag_verify(chunk
, asoc
))
1089 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1091 /* Make sure that the HEARTBEAT chunk has a valid length. */
1092 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1093 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1096 /* 8.3 The receiver of the HEARTBEAT should immediately
1097 * respond with a HEARTBEAT ACK that contains the Heartbeat
1098 * Information field copied from the received HEARTBEAT chunk.
1100 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1101 param_hdr
= (sctp_paramhdr_t
*) chunk
->subh
.hb_hdr
;
1102 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1104 if (ntohs(param_hdr
->length
) > paylen
)
1105 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
1106 param_hdr
, commands
);
1108 if (!pskb_pull(chunk
->skb
, paylen
))
1111 reply
= sctp_make_heartbeat_ack(asoc
, chunk
, param_hdr
, paylen
);
1115 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1116 return SCTP_DISPOSITION_CONSUME
;
1119 return SCTP_DISPOSITION_NOMEM
;
1123 * Process the returning HEARTBEAT ACK.
1125 * Section: 8.3 Path Heartbeat
1126 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1127 * should clear the error counter of the destination transport
1128 * address to which the HEARTBEAT was sent, and mark the destination
1129 * transport address as active if it is not so marked. The endpoint may
1130 * optionally report to the upper layer when an inactive destination
1131 * address is marked as active due to the reception of the latest
1132 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1133 * clear the association overall error count as well (as defined
1136 * The receiver of the HEARTBEAT ACK should also perform an RTT
1137 * measurement for that destination transport address using the time
1138 * value carried in the HEARTBEAT ACK chunk.
1140 * Verification Tag: 8.5 Verification Tag [Normal verification]
1143 * (endpoint, asoc, chunk)
1146 * (asoc, reply_msg, msg_up, timers, counters)
1148 * The return value is the disposition of the chunk.
1150 sctp_disposition_t
sctp_sf_backbeat_8_3(struct net
*net
,
1151 const struct sctp_endpoint
*ep
,
1152 const struct sctp_association
*asoc
,
1153 const sctp_subtype_t type
,
1155 sctp_cmd_seq_t
*commands
)
1157 struct sctp_chunk
*chunk
= arg
;
1158 union sctp_addr from_addr
;
1159 struct sctp_transport
*link
;
1160 sctp_sender_hb_info_t
*hbinfo
;
1161 unsigned long max_interval
;
1163 if (!sctp_vtag_verify(chunk
, asoc
))
1164 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1166 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1167 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
) +
1168 sizeof(sctp_sender_hb_info_t
)))
1169 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1172 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1173 /* Make sure that the length of the parameter is what we expect */
1174 if (ntohs(hbinfo
->param_hdr
.length
) !=
1175 sizeof(sctp_sender_hb_info_t
)) {
1176 return SCTP_DISPOSITION_DISCARD
;
1179 from_addr
= hbinfo
->daddr
;
1180 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1182 /* This should never happen, but lets log it if so. */
1183 if (unlikely(!link
)) {
1184 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1185 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1188 &from_addr
.v6
.sin6_addr
);
1190 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1193 &from_addr
.v4
.sin_addr
.s_addr
);
1195 return SCTP_DISPOSITION_DISCARD
;
1198 /* Validate the 64-bit random nonce. */
1199 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1200 return SCTP_DISPOSITION_DISCARD
;
1202 max_interval
= link
->hbinterval
+ link
->rto
;
1204 /* Check if the timestamp looks valid. */
1205 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1206 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1207 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1208 "for transport:%p\n", __func__
, link
);
1210 return SCTP_DISPOSITION_DISCARD
;
1213 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1214 * the HEARTBEAT should clear the error counter of the
1215 * destination transport address to which the HEARTBEAT was
1216 * sent and mark the destination transport address as active if
1217 * it is not so marked.
1219 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1221 return SCTP_DISPOSITION_CONSUME
;
1224 /* Helper function to send out an abort for the restart
1227 static int sctp_sf_send_restart_abort(struct net
*net
, union sctp_addr
*ssa
,
1228 struct sctp_chunk
*init
,
1229 sctp_cmd_seq_t
*commands
)
1232 struct sctp_packet
*pkt
;
1233 union sctp_addr_param
*addrparm
;
1234 struct sctp_errhdr
*errhdr
;
1235 struct sctp_endpoint
*ep
;
1236 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1237 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1239 /* Build the error on the stack. We are way to malloc crazy
1240 * throughout the code today.
1242 errhdr
= (struct sctp_errhdr
*)buffer
;
1243 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1245 /* Copy into a parm format. */
1246 len
= af
->to_addr_param(ssa
, addrparm
);
1247 len
+= sizeof(sctp_errhdr_t
);
1249 errhdr
->cause
= SCTP_ERROR_RESTART
;
1250 errhdr
->length
= htons(len
);
1252 /* Assign to the control socket. */
1253 ep
= sctp_sk(net
->sctp
.ctl_sock
)->ep
;
1255 /* Association is NULL since this may be a restart attack and we
1256 * want to send back the attacker's vtag.
1258 pkt
= sctp_abort_pkt_new(net
, ep
, NULL
, init
, errhdr
, len
);
1262 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1264 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1266 /* Discard the rest of the inbound packet. */
1267 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1270 /* Even if there is no memory, treat as a failure so
1271 * the packet will get dropped.
1276 static bool list_has_sctp_addr(const struct list_head
*list
,
1277 union sctp_addr
*ipaddr
)
1279 struct sctp_transport
*addr
;
1281 list_for_each_entry(addr
, list
, transports
) {
1282 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1288 /* A restart is occurring, check to make sure no new addresses
1289 * are being added as we may be under a takeover attack.
1291 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1292 const struct sctp_association
*asoc
,
1293 struct sctp_chunk
*init
,
1294 sctp_cmd_seq_t
*commands
)
1296 struct net
*net
= sock_net(new_asoc
->base
.sk
);
1297 struct sctp_transport
*new_addr
;
1300 /* Implementor's Guide - Section 5.2.2
1302 * Before responding the endpoint MUST check to see if the
1303 * unexpected INIT adds new addresses to the association. If new
1304 * addresses are added to the association, the endpoint MUST respond
1308 /* Search through all current addresses and make sure
1309 * we aren't adding any new ones.
1311 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1313 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1314 &new_addr
->ipaddr
)) {
1315 sctp_sf_send_restart_abort(net
, &new_addr
->ipaddr
, init
,
1322 /* Return success if all addresses were found. */
1326 /* Populate the verification/tie tags based on overlapping INIT
1329 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1331 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1332 const struct sctp_association
*asoc
)
1334 switch (asoc
->state
) {
1336 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1338 case SCTP_STATE_COOKIE_WAIT
:
1339 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1340 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1341 new_asoc
->c
.peer_ttag
= 0;
1344 case SCTP_STATE_COOKIE_ECHOED
:
1345 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1346 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1347 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1350 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1351 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1354 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1355 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1359 /* Other parameters for the endpoint SHOULD be copied from the
1360 * existing parameters of the association (e.g. number of
1361 * outbound streams) into the INIT ACK and cookie.
1363 new_asoc
->rwnd
= asoc
->rwnd
;
1364 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1365 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1366 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1370 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1373 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1375 * Returns value representing action to be taken. These action values
1376 * correspond to Action/Description values in RFC 2960, Table 2.
1378 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1379 const struct sctp_association
*asoc
)
1381 /* In this case, the peer may have restarted. */
1382 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1383 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1384 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1385 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1388 /* Collision case B. */
1389 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1390 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1391 (0 == asoc
->c
.peer_vtag
))) {
1395 /* Collision case D. */
1396 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1397 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1400 /* Collision case C. */
1401 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1402 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1403 (0 == new_asoc
->c
.my_ttag
) &&
1404 (0 == new_asoc
->c
.peer_ttag
))
1407 /* No match to any of the special cases; discard this packet. */
1411 /* Common helper routine for both duplicate and simulataneous INIT
1414 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1416 const struct sctp_endpoint
*ep
,
1417 const struct sctp_association
*asoc
,
1418 const sctp_subtype_t type
,
1419 void *arg
, sctp_cmd_seq_t
*commands
)
1421 sctp_disposition_t retval
;
1422 struct sctp_chunk
*chunk
= arg
;
1423 struct sctp_chunk
*repl
;
1424 struct sctp_association
*new_asoc
;
1425 struct sctp_chunk
*err_chunk
;
1426 struct sctp_packet
*packet
;
1427 sctp_unrecognized_param_t
*unk_param
;
1431 * An endpoint MUST NOT bundle INIT, INIT ACK or
1432 * SHUTDOWN COMPLETE with any other chunks.
1435 * Furthermore, we require that the receiver of an INIT chunk MUST
1436 * enforce these rules by silently discarding an arriving packet
1437 * with an INIT chunk that is bundled with other chunks.
1439 if (!chunk
->singleton
)
1440 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1442 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1445 if (chunk
->sctp_hdr
->vtag
!= 0)
1446 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
1448 /* Make sure that the INIT chunk has a valid length.
1449 * In this case, we generate a protocol violation since we have
1450 * an association established.
1452 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1453 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1455 /* Grab the INIT header. */
1456 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1458 /* Tag the variable length parameters. */
1459 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1461 /* Verify the INIT chunk before processing it. */
1463 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
1464 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1466 /* This chunk contains fatal error. It is to be discarded.
1467 * Send an ABORT, with causes if there is any.
1470 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
1471 (__u8
*)(err_chunk
->chunk_hdr
) +
1472 sizeof(sctp_chunkhdr_t
),
1473 ntohs(err_chunk
->chunk_hdr
->length
) -
1474 sizeof(sctp_chunkhdr_t
));
1477 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1478 SCTP_PACKET(packet
));
1479 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1480 retval
= SCTP_DISPOSITION_CONSUME
;
1482 retval
= SCTP_DISPOSITION_NOMEM
;
1486 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
1492 * Other parameters for the endpoint SHOULD be copied from the
1493 * existing parameters of the association (e.g. number of
1494 * outbound streams) into the INIT ACK and cookie.
1495 * FIXME: We are copying parameters from the endpoint not the
1498 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1502 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1503 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1506 /* In the outbound INIT ACK the endpoint MUST copy its current
1507 * Verification Tag and Peers Verification tag into a reserved
1508 * place (local tie-tag and per tie-tag) within the state cookie.
1510 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
1511 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1515 /* Make sure no new addresses are being added during the
1516 * restart. Do not do this check for COOKIE-WAIT state,
1517 * since there are no peer addresses to check against.
1518 * Upon return an ABORT will have been sent if needed.
1520 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1521 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1523 retval
= SCTP_DISPOSITION_CONSUME
;
1528 sctp_tietags_populate(new_asoc
, asoc
);
1530 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1532 /* If there are errors need to be reported for unknown parameters,
1533 * make sure to reserve enough room in the INIT ACK for them.
1537 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1538 sizeof(sctp_chunkhdr_t
);
1541 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1545 /* If there are errors need to be reported for unknown parameters,
1546 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1550 /* Get the "Unrecognized parameter" parameter(s) out of the
1551 * ERROR chunk generated by sctp_verify_init(). Since the
1552 * error cause code for "unknown parameter" and the
1553 * "Unrecognized parameter" type is the same, we can
1554 * construct the parameters in INIT ACK by copying the
1555 * ERROR causes over.
1557 unk_param
= (sctp_unrecognized_param_t
*)
1558 ((__u8
*)(err_chunk
->chunk_hdr
) +
1559 sizeof(sctp_chunkhdr_t
));
1560 /* Replace the cause code with the "Unrecognized parameter"
1563 sctp_addto_chunk(repl
, len
, unk_param
);
1566 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1567 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1570 * Note: After sending out INIT ACK with the State Cookie parameter,
1571 * "Z" MUST NOT allocate any resources for this new association.
1572 * Otherwise, "Z" will be vulnerable to resource attacks.
1574 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1575 retval
= SCTP_DISPOSITION_CONSUME
;
1580 retval
= SCTP_DISPOSITION_NOMEM
;
1583 sctp_association_free(new_asoc
);
1586 sctp_chunk_free(err_chunk
);
1591 * Handle simultaneous INIT.
1592 * This means we started an INIT and then we got an INIT request from
1595 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1596 * This usually indicates an initialization collision, i.e., each
1597 * endpoint is attempting, at about the same time, to establish an
1598 * association with the other endpoint.
1600 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1601 * endpoint MUST respond with an INIT ACK using the same parameters it
1602 * sent in its original INIT chunk (including its Verification Tag,
1603 * unchanged). These original parameters are combined with those from the
1604 * newly received INIT chunk. The endpoint shall also generate a State
1605 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1606 * INIT to calculate the State Cookie.
1608 * After that, the endpoint MUST NOT change its state, the T1-init
1609 * timer shall be left running and the corresponding TCB MUST NOT be
1610 * destroyed. The normal procedures for handling State Cookies when
1611 * a TCB exists will resolve the duplicate INITs to a single association.
1613 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1614 * its Tie-Tags with the Tag information of itself and its peer (see
1615 * section 5.2.2 for a description of the Tie-Tags).
1617 * Verification Tag: Not explicit, but an INIT can not have a valid
1618 * verification tag, so we skip the check.
1621 * (endpoint, asoc, chunk)
1624 * (asoc, reply_msg, msg_up, timers, counters)
1626 * The return value is the disposition of the chunk.
1628 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(struct net
*net
,
1629 const struct sctp_endpoint
*ep
,
1630 const struct sctp_association
*asoc
,
1631 const sctp_subtype_t type
,
1633 sctp_cmd_seq_t
*commands
)
1635 /* Call helper to do the real work for both simulataneous and
1636 * duplicate INIT chunk handling.
1638 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1642 * Handle duplicated INIT messages. These are usually delayed
1645 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1646 * COOKIE-ECHOED and COOKIE-WAIT
1648 * Unless otherwise stated, upon reception of an unexpected INIT for
1649 * this association, the endpoint shall generate an INIT ACK with a
1650 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1651 * current Verification Tag and peer's Verification Tag into a reserved
1652 * place within the state cookie. We shall refer to these locations as
1653 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1654 * containing this INIT ACK MUST carry a Verification Tag value equal to
1655 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1656 * MUST contain a new Initiation Tag (randomly generated see Section
1657 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1658 * existing parameters of the association (e.g. number of outbound
1659 * streams) into the INIT ACK and cookie.
1661 * After sending out the INIT ACK, the endpoint shall take no further
1662 * actions, i.e., the existing association, including its current state,
1663 * and the corresponding TCB MUST NOT be changed.
1665 * Note: Only when a TCB exists and the association is not in a COOKIE-
1666 * WAIT state are the Tie-Tags populated. For a normal association INIT
1667 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1668 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1669 * State Cookie are populated as specified in section 5.2.1.
1671 * Verification Tag: Not specified, but an INIT has no way of knowing
1672 * what the verification tag could be, so we ignore it.
1675 * (endpoint, asoc, chunk)
1678 * (asoc, reply_msg, msg_up, timers, counters)
1680 * The return value is the disposition of the chunk.
1682 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(struct net
*net
,
1683 const struct sctp_endpoint
*ep
,
1684 const struct sctp_association
*asoc
,
1685 const sctp_subtype_t type
,
1687 sctp_cmd_seq_t
*commands
)
1689 /* Call helper to do the real work for both simulataneous and
1690 * duplicate INIT chunk handling.
1692 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1697 * Unexpected INIT-ACK handler.
1700 * If an INIT ACK received by an endpoint in any state other than the
1701 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1702 * An unexpected INIT ACK usually indicates the processing of an old or
1703 * duplicated INIT chunk.
1705 sctp_disposition_t
sctp_sf_do_5_2_3_initack(struct net
*net
,
1706 const struct sctp_endpoint
*ep
,
1707 const struct sctp_association
*asoc
,
1708 const sctp_subtype_t type
,
1709 void *arg
, sctp_cmd_seq_t
*commands
)
1711 /* Per the above section, we'll discard the chunk if we have an
1712 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1714 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
)
1715 return sctp_sf_ootb(net
, ep
, asoc
, type
, arg
, commands
);
1717 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
1720 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1723 * A) In this case, the peer may have restarted.
1725 static sctp_disposition_t
sctp_sf_do_dupcook_a(struct net
*net
,
1726 const struct sctp_endpoint
*ep
,
1727 const struct sctp_association
*asoc
,
1728 struct sctp_chunk
*chunk
,
1729 sctp_cmd_seq_t
*commands
,
1730 struct sctp_association
*new_asoc
)
1732 sctp_init_chunk_t
*peer_init
;
1733 struct sctp_ulpevent
*ev
;
1734 struct sctp_chunk
*repl
;
1735 struct sctp_chunk
*err
;
1736 sctp_disposition_t disposition
;
1738 /* new_asoc is a brand-new association, so these are not yet
1739 * side effects--it is safe to run them here.
1741 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1743 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1747 /* Make sure no new addresses are being added during the
1748 * restart. Though this is a pretty complicated attack
1749 * since you'd have to get inside the cookie.
1751 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1752 return SCTP_DISPOSITION_CONSUME
;
1755 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1756 * the peer has restarted (Action A), it MUST NOT setup a new
1757 * association but instead resend the SHUTDOWN ACK and send an ERROR
1758 * chunk with a "Cookie Received while Shutting Down" error cause to
1761 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1762 disposition
= sctp_sf_do_9_2_reshutack(net
, ep
, asoc
,
1763 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1765 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1768 err
= sctp_make_op_error(asoc
, chunk
,
1769 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1772 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1775 return SCTP_DISPOSITION_CONSUME
;
1778 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1779 * data. Consider the optional choice of resending of this data.
1781 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
1782 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1783 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
1784 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1786 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1787 * and ASCONF-ACK cache.
1789 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1790 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
1791 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_ASCONF_QUEUE
, SCTP_NULL());
1793 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1797 /* Report association restart to upper layer. */
1798 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1799 new_asoc
->c
.sinit_num_ostreams
,
1800 new_asoc
->c
.sinit_max_instreams
,
1805 /* Update the content of current association. */
1806 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1807 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1808 if (sctp_state(asoc
, SHUTDOWN_PENDING
) &&
1809 (sctp_sstate(asoc
->base
.sk
, CLOSING
) ||
1810 sock_flag(asoc
->base
.sk
, SOCK_DEAD
))) {
1811 /* if were currently in SHUTDOWN_PENDING, but the socket
1812 * has been closed by user, don't transition to ESTABLISHED.
1813 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1815 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1816 return sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
,
1817 SCTP_ST_CHUNK(0), NULL
,
1820 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1821 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1822 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1824 return SCTP_DISPOSITION_CONSUME
;
1827 sctp_chunk_free(repl
);
1829 return SCTP_DISPOSITION_NOMEM
;
1832 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1835 * B) In this case, both sides may be attempting to start an association
1836 * at about the same time but the peer endpoint started its INIT
1837 * after responding to the local endpoint's INIT
1839 /* This case represents an initialization collision. */
1840 static sctp_disposition_t
sctp_sf_do_dupcook_b(struct net
*net
,
1841 const struct sctp_endpoint
*ep
,
1842 const struct sctp_association
*asoc
,
1843 struct sctp_chunk
*chunk
,
1844 sctp_cmd_seq_t
*commands
,
1845 struct sctp_association
*new_asoc
)
1847 sctp_init_chunk_t
*peer_init
;
1848 struct sctp_chunk
*repl
;
1850 /* new_asoc is a brand-new association, so these are not yet
1851 * side effects--it is safe to run them here.
1853 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1854 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1858 /* Update the content of current association. */
1859 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1860 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1861 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1862 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1863 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1865 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1869 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1871 /* RFC 2960 5.1 Normal Establishment of an Association
1873 * D) IMPLEMENTATION NOTE: An implementation may choose to
1874 * send the Communication Up notification to the SCTP user
1875 * upon reception of a valid COOKIE ECHO chunk.
1877 * Sadly, this needs to be implemented as a side-effect, because
1878 * we are not guaranteed to have set the association id of the real
1879 * association and so these notifications need to be delayed until
1880 * the association id is allocated.
1883 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1885 /* Sockets API Draft Section 5.3.1.6
1886 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1887 * delivers this notification to inform the application that of the
1888 * peers requested adaptation layer.
1890 * This also needs to be done as a side effect for the same reason as
1893 if (asoc
->peer
.adaptation_ind
)
1894 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1896 return SCTP_DISPOSITION_CONSUME
;
1899 return SCTP_DISPOSITION_NOMEM
;
1902 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1905 * C) In this case, the local endpoint's cookie has arrived late.
1906 * Before it arrived, the local endpoint sent an INIT and received an
1907 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1908 * but a new tag of its own.
1910 /* This case represents an initialization collision. */
1911 static sctp_disposition_t
sctp_sf_do_dupcook_c(struct net
*net
,
1912 const struct sctp_endpoint
*ep
,
1913 const struct sctp_association
*asoc
,
1914 struct sctp_chunk
*chunk
,
1915 sctp_cmd_seq_t
*commands
,
1916 struct sctp_association
*new_asoc
)
1918 /* The cookie should be silently discarded.
1919 * The endpoint SHOULD NOT change states and should leave
1920 * any timers running.
1922 return SCTP_DISPOSITION_DISCARD
;
1925 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1929 * D) When both local and remote tags match the endpoint should always
1930 * enter the ESTABLISHED state, if it has not already done so.
1932 /* This case represents an initialization collision. */
1933 static sctp_disposition_t
sctp_sf_do_dupcook_d(struct net
*net
,
1934 const struct sctp_endpoint
*ep
,
1935 const struct sctp_association
*asoc
,
1936 struct sctp_chunk
*chunk
,
1937 sctp_cmd_seq_t
*commands
,
1938 struct sctp_association
*new_asoc
)
1940 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1941 struct sctp_chunk
*repl
;
1943 /* Clarification from Implementor's Guide:
1944 * D) When both local and remote tags match the endpoint should
1945 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1946 * It should stop any cookie timer that may be running and send
1950 /* Don't accidentally move back into established state. */
1951 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1952 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1953 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1954 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1955 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1956 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1957 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1960 /* RFC 2960 5.1 Normal Establishment of an Association
1962 * D) IMPLEMENTATION NOTE: An implementation may choose
1963 * to send the Communication Up notification to the
1964 * SCTP user upon reception of a valid COOKIE
1967 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1969 asoc
->c
.sinit_num_ostreams
,
1970 asoc
->c
.sinit_max_instreams
,
1975 /* Sockets API Draft Section 5.3.1.6
1976 * When a peer sends a Adaptation Layer Indication parameter,
1977 * SCTP delivers this notification to inform the application
1978 * that of the peers requested adaptation layer.
1980 if (asoc
->peer
.adaptation_ind
) {
1981 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1989 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1993 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1996 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1999 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
2000 SCTP_ULPEVENT(ai_ev
));
2002 return SCTP_DISPOSITION_CONSUME
;
2006 sctp_ulpevent_free(ai_ev
);
2008 sctp_ulpevent_free(ev
);
2009 return SCTP_DISPOSITION_NOMEM
;
2013 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2014 * chunk was retransmitted and then delayed in the network.
2016 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2018 * Verification Tag: None. Do cookie validation.
2021 * (endpoint, asoc, chunk)
2024 * (asoc, reply_msg, msg_up, timers, counters)
2026 * The return value is the disposition of the chunk.
2028 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(struct net
*net
,
2029 const struct sctp_endpoint
*ep
,
2030 const struct sctp_association
*asoc
,
2031 const sctp_subtype_t type
,
2033 sctp_cmd_seq_t
*commands
)
2035 sctp_disposition_t retval
;
2036 struct sctp_chunk
*chunk
= arg
;
2037 struct sctp_association
*new_asoc
;
2040 struct sctp_chunk
*err_chk_p
;
2042 /* Make sure that the chunk has a valid length from the protocol
2043 * perspective. In this case check to make sure we have at least
2044 * enough for the chunk header. Cookie length verification is
2047 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2048 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2051 /* "Decode" the chunk. We have no optional parameters so we
2052 * are in good shape.
2054 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
2055 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
2056 sizeof(sctp_chunkhdr_t
)))
2059 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2060 * of a duplicate COOKIE ECHO match the Verification Tags of the
2061 * current association, consider the State Cookie valid even if
2062 * the lifespan is exceeded.
2064 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
2068 * If the re-build failed, what is the proper error path
2071 * [We should abort the association. --piggy]
2074 /* FIXME: Several errors are possible. A bad cookie should
2075 * be silently discarded, but think about logging it too.
2078 case -SCTP_IERROR_NOMEM
:
2081 case -SCTP_IERROR_STALE_COOKIE
:
2082 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
2084 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2085 case -SCTP_IERROR_BAD_SIG
:
2087 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2091 /* Compare the tie_tag in cookie with the verification tag of
2092 * current association.
2094 action
= sctp_tietags_compare(new_asoc
, asoc
);
2097 case 'A': /* Association restart. */
2098 retval
= sctp_sf_do_dupcook_a(net
, ep
, asoc
, chunk
, commands
,
2102 case 'B': /* Collision case B. */
2103 retval
= sctp_sf_do_dupcook_b(net
, ep
, asoc
, chunk
, commands
,
2107 case 'C': /* Collision case C. */
2108 retval
= sctp_sf_do_dupcook_c(net
, ep
, asoc
, chunk
, commands
,
2112 case 'D': /* Collision case D. */
2113 retval
= sctp_sf_do_dupcook_d(net
, ep
, asoc
, chunk
, commands
,
2117 default: /* Discard packet for all others. */
2118 retval
= sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2122 /* Delete the tempory new association. */
2123 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
, SCTP_ASOC(new_asoc
));
2124 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2126 /* Restore association pointer to provide SCTP command interpeter
2127 * with a valid context in case it needs to manipulate
2129 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
,
2130 SCTP_ASOC((struct sctp_association
*)asoc
));
2135 return SCTP_DISPOSITION_NOMEM
;
2139 * Process an ABORT. (SHUTDOWN-PENDING state)
2141 * See sctp_sf_do_9_1_abort().
2143 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2145 const struct sctp_endpoint
*ep
,
2146 const struct sctp_association
*asoc
,
2147 const sctp_subtype_t type
,
2149 sctp_cmd_seq_t
*commands
)
2151 struct sctp_chunk
*chunk
= arg
;
2153 if (!sctp_vtag_verify_either(chunk
, asoc
))
2154 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2156 /* Make sure that the ABORT chunk has a valid length.
2157 * Since this is an ABORT chunk, we have to discard it
2158 * because of the following text:
2159 * RFC 2960, Section 3.3.7
2160 * If an endpoint receives an ABORT with a format error or for an
2161 * association that doesn't exist, it MUST silently discard it.
2162 * Because the length is "invalid", we can't really discard just
2163 * as we do not know its true length. So, to be safe, discard the
2166 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2167 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2169 /* ADD-IP: Special case for ABORT chunks
2170 * F4) One special consideration is that ABORT Chunks arriving
2171 * destined to the IP address being deleted MUST be
2172 * ignored (see Section 5.3.1 for further details).
2174 if (SCTP_ADDR_DEL
==
2175 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2176 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2178 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2182 * Process an ABORT. (SHUTDOWN-SENT state)
2184 * See sctp_sf_do_9_1_abort().
2186 sctp_disposition_t
sctp_sf_shutdown_sent_abort(struct net
*net
,
2187 const struct sctp_endpoint
*ep
,
2188 const struct sctp_association
*asoc
,
2189 const sctp_subtype_t type
,
2191 sctp_cmd_seq_t
*commands
)
2193 struct sctp_chunk
*chunk
= arg
;
2195 if (!sctp_vtag_verify_either(chunk
, asoc
))
2196 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2198 /* Make sure that the ABORT chunk has a valid length.
2199 * Since this is an ABORT chunk, we have to discard it
2200 * because of the following text:
2201 * RFC 2960, Section 3.3.7
2202 * If an endpoint receives an ABORT with a format error or for an
2203 * association that doesn't exist, it MUST silently discard it.
2204 * Because the length is "invalid", we can't really discard just
2205 * as we do not know its true length. So, to be safe, discard the
2208 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2209 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2211 /* ADD-IP: Special case for ABORT chunks
2212 * F4) One special consideration is that ABORT Chunks arriving
2213 * destined to the IP address being deleted MUST be
2214 * ignored (see Section 5.3.1 for further details).
2216 if (SCTP_ADDR_DEL
==
2217 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2218 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2220 /* Stop the T2-shutdown timer. */
2221 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2222 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2224 /* Stop the T5-shutdown guard timer. */
2225 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2226 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2228 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2232 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2234 * See sctp_sf_do_9_1_abort().
2236 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2238 const struct sctp_endpoint
*ep
,
2239 const struct sctp_association
*asoc
,
2240 const sctp_subtype_t type
,
2242 sctp_cmd_seq_t
*commands
)
2244 /* The same T2 timer, so we should be able to use
2245 * common function with the SHUTDOWN-SENT state.
2247 return sctp_sf_shutdown_sent_abort(net
, ep
, asoc
, type
, arg
, commands
);
2251 * Handle an Error received in COOKIE_ECHOED state.
2253 * Only handle the error type of stale COOKIE Error, the other errors will
2257 * (endpoint, asoc, chunk)
2260 * (asoc, reply_msg, msg_up, timers, counters)
2262 * The return value is the disposition of the chunk.
2264 sctp_disposition_t
sctp_sf_cookie_echoed_err(struct net
*net
,
2265 const struct sctp_endpoint
*ep
,
2266 const struct sctp_association
*asoc
,
2267 const sctp_subtype_t type
,
2269 sctp_cmd_seq_t
*commands
)
2271 struct sctp_chunk
*chunk
= arg
;
2274 if (!sctp_vtag_verify(chunk
, asoc
))
2275 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2277 /* Make sure that the ERROR chunk has a valid length.
2278 * The parameter walking depends on this as well.
2280 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2281 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2284 /* Process the error here */
2285 /* FUTURE FIXME: When PR-SCTP related and other optional
2286 * parms are emitted, this will have to change to handle multiple
2289 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2290 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2291 return sctp_sf_do_5_2_6_stale(net
, ep
, asoc
, type
,
2295 /* It is possible to have malformed error causes, and that
2296 * will cause us to end the walk early. However, since
2297 * we are discarding the packet, there should be no adverse
2300 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2304 * Handle a Stale COOKIE Error
2306 * Section: 5.2.6 Handle Stale COOKIE Error
2307 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2308 * one of the following three alternatives.
2310 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2311 * Preservative parameter requesting an extension to the lifetime of
2312 * the State Cookie. When calculating the time extension, an
2313 * implementation SHOULD use the RTT information measured based on the
2314 * previous COOKIE ECHO / ERROR exchange, and should add no more
2315 * than 1 second beyond the measured RTT, due to long State Cookie
2316 * lifetimes making the endpoint more subject to a replay attack.
2318 * Verification Tag: Not explicit, but safe to ignore.
2321 * (endpoint, asoc, chunk)
2324 * (asoc, reply_msg, msg_up, timers, counters)
2326 * The return value is the disposition of the chunk.
2328 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(struct net
*net
,
2329 const struct sctp_endpoint
*ep
,
2330 const struct sctp_association
*asoc
,
2331 const sctp_subtype_t type
,
2333 sctp_cmd_seq_t
*commands
)
2335 struct sctp_chunk
*chunk
= arg
;
2337 sctp_cookie_preserve_param_t bht
;
2339 struct sctp_chunk
*reply
;
2340 struct sctp_bind_addr
*bp
;
2341 int attempts
= asoc
->init_err_counter
+ 1;
2343 if (attempts
> asoc
->max_init_attempts
) {
2344 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2345 SCTP_ERROR(ETIMEDOUT
));
2346 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2347 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2348 return SCTP_DISPOSITION_DELETE_TCB
;
2351 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2353 /* When calculating the time extension, an implementation
2354 * SHOULD use the RTT information measured based on the
2355 * previous COOKIE ECHO / ERROR exchange, and should add no
2356 * more than 1 second beyond the measured RTT, due to long
2357 * State Cookie lifetimes making the endpoint more subject to
2359 * Measure of Staleness's unit is usec. (1/1000000 sec)
2360 * Suggested Cookie Life-span Increment's unit is msec.
2362 * In general, if you use the suggested cookie life, the value
2363 * found in the field of measure of staleness should be doubled
2364 * to give ample time to retransmit the new cookie and thus
2365 * yield a higher probability of success on the reattempt.
2367 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2368 stale
= (stale
* 2) / 1000;
2370 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2371 bht
.param_hdr
.length
= htons(sizeof(bht
));
2372 bht
.lifespan_increment
= htonl(stale
);
2374 /* Build that new INIT chunk. */
2375 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2376 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2380 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2382 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2383 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2385 /* Stop pending T3-rtx and heartbeat timers */
2386 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2387 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2389 /* Delete non-primary peer ip addresses since we are transitioning
2390 * back to the COOKIE-WAIT state
2392 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2394 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2397 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2398 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2400 /* Cast away the const modifier, as we want to just
2401 * rerun it through as a sideffect.
2403 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2405 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2406 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2407 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2408 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2409 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2410 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2412 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2414 return SCTP_DISPOSITION_CONSUME
;
2417 return SCTP_DISPOSITION_NOMEM
;
2424 * After checking the Verification Tag, the receiving endpoint shall
2425 * remove the association from its record, and shall report the
2426 * termination to its upper layer.
2428 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2429 * B) Rules for packet carrying ABORT:
2431 * - The endpoint shall always fill in the Verification Tag field of the
2432 * outbound packet with the destination endpoint's tag value if it
2435 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2436 * MUST follow the procedure described in Section 8.4.
2438 * - The receiver MUST accept the packet if the Verification Tag
2439 * matches either its own tag, OR the tag of its peer. Otherwise, the
2440 * receiver MUST silently discard the packet and take no further
2444 * (endpoint, asoc, chunk)
2447 * (asoc, reply_msg, msg_up, timers, counters)
2449 * The return value is the disposition of the chunk.
2451 sctp_disposition_t
sctp_sf_do_9_1_abort(struct net
*net
,
2452 const struct sctp_endpoint
*ep
,
2453 const struct sctp_association
*asoc
,
2454 const sctp_subtype_t type
,
2456 sctp_cmd_seq_t
*commands
)
2458 struct sctp_chunk
*chunk
= arg
;
2460 if (!sctp_vtag_verify_either(chunk
, asoc
))
2461 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2463 /* Make sure that the ABORT chunk has a valid length.
2464 * Since this is an ABORT chunk, we have to discard it
2465 * because of the following text:
2466 * RFC 2960, Section 3.3.7
2467 * If an endpoint receives an ABORT with a format error or for an
2468 * association that doesn't exist, it MUST silently discard it.
2469 * Because the length is "invalid", we can't really discard just
2470 * as we do not know its true length. So, to be safe, discard the
2473 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2474 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2476 /* ADD-IP: Special case for ABORT chunks
2477 * F4) One special consideration is that ABORT Chunks arriving
2478 * destined to the IP address being deleted MUST be
2479 * ignored (see Section 5.3.1 for further details).
2481 if (SCTP_ADDR_DEL
==
2482 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2483 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2485 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2488 static sctp_disposition_t
__sctp_sf_do_9_1_abort(struct net
*net
,
2489 const struct sctp_endpoint
*ep
,
2490 const struct sctp_association
*asoc
,
2491 const sctp_subtype_t type
,
2493 sctp_cmd_seq_t
*commands
)
2495 struct sctp_chunk
*chunk
= arg
;
2497 __be16 error
= SCTP_ERROR_NO_ERROR
;
2499 /* See if we have an error cause code in the chunk. */
2500 len
= ntohs(chunk
->chunk_hdr
->length
);
2501 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2504 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2505 if ((void *)err
!= (void *)chunk
->chunk_end
)
2506 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2508 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2511 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2512 /* ASSOC_FAILED will DELETE_TCB. */
2513 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2514 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2515 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
2517 return SCTP_DISPOSITION_ABORT
;
2521 * Process an ABORT. (COOKIE-WAIT state)
2523 * See sctp_sf_do_9_1_abort() above.
2525 sctp_disposition_t
sctp_sf_cookie_wait_abort(struct net
*net
,
2526 const struct sctp_endpoint
*ep
,
2527 const struct sctp_association
*asoc
,
2528 const sctp_subtype_t type
,
2530 sctp_cmd_seq_t
*commands
)
2532 struct sctp_chunk
*chunk
= arg
;
2534 __be16 error
= SCTP_ERROR_NO_ERROR
;
2536 if (!sctp_vtag_verify_either(chunk
, asoc
))
2537 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2539 /* Make sure that the ABORT chunk has a valid length.
2540 * Since this is an ABORT chunk, we have to discard it
2541 * because of the following text:
2542 * RFC 2960, Section 3.3.7
2543 * If an endpoint receives an ABORT with a format error or for an
2544 * association that doesn't exist, it MUST silently discard it.
2545 * Because the length is "invalid", we can't really discard just
2546 * as we do not know its true length. So, to be safe, discard the
2549 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2550 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2552 /* See if we have an error cause code in the chunk. */
2553 len
= ntohs(chunk
->chunk_hdr
->length
);
2554 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2555 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2557 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
, asoc
,
2562 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2564 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(struct net
*net
,
2565 const struct sctp_endpoint
*ep
,
2566 const struct sctp_association
*asoc
,
2567 const sctp_subtype_t type
,
2569 sctp_cmd_seq_t
*commands
)
2571 return sctp_stop_t1_and_abort(net
, commands
, SCTP_ERROR_NO_ERROR
,
2573 (struct sctp_transport
*)arg
);
2577 * Process an ABORT. (COOKIE-ECHOED state)
2579 sctp_disposition_t
sctp_sf_cookie_echoed_abort(struct net
*net
,
2580 const struct sctp_endpoint
*ep
,
2581 const struct sctp_association
*asoc
,
2582 const sctp_subtype_t type
,
2584 sctp_cmd_seq_t
*commands
)
2586 /* There is a single T1 timer, so we should be able to use
2587 * common function with the COOKIE-WAIT state.
2589 return sctp_sf_cookie_wait_abort(net
, ep
, asoc
, type
, arg
, commands
);
2593 * Stop T1 timer and abort association with "INIT failed".
2595 * This is common code called by several sctp_sf_*_abort() functions above.
2597 static sctp_disposition_t
sctp_stop_t1_and_abort(struct net
*net
,
2598 sctp_cmd_seq_t
*commands
,
2599 __be16 error
, int sk_err
,
2600 const struct sctp_association
*asoc
,
2601 struct sctp_transport
*transport
)
2603 pr_debug("%s: ABORT received (INIT)\n", __func__
);
2605 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2606 SCTP_STATE(SCTP_STATE_CLOSED
));
2607 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2608 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2609 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2610 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2611 /* CMD_INIT_FAILED will DELETE_TCB. */
2612 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2615 return SCTP_DISPOSITION_ABORT
;
2619 * sctp_sf_do_9_2_shut
2622 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2623 * - enter the SHUTDOWN-RECEIVED state,
2625 * - stop accepting new data from its SCTP user
2627 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2628 * that all its outstanding DATA chunks have been received by the
2631 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2632 * send a SHUTDOWN in response to a ULP request. And should discard
2633 * subsequent SHUTDOWN chunks.
2635 * If there are still outstanding DATA chunks left, the SHUTDOWN
2636 * receiver shall continue to follow normal data transmission
2637 * procedures defined in Section 6 until all outstanding DATA chunks
2638 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2639 * new data from its SCTP user.
2641 * Verification Tag: 8.5 Verification Tag [Normal verification]
2644 * (endpoint, asoc, chunk)
2647 * (asoc, reply_msg, msg_up, timers, counters)
2649 * The return value is the disposition of the chunk.
2651 sctp_disposition_t
sctp_sf_do_9_2_shutdown(struct net
*net
,
2652 const struct sctp_endpoint
*ep
,
2653 const struct sctp_association
*asoc
,
2654 const sctp_subtype_t type
,
2656 sctp_cmd_seq_t
*commands
)
2658 struct sctp_chunk
*chunk
= arg
;
2659 sctp_shutdownhdr_t
*sdh
;
2660 sctp_disposition_t disposition
;
2661 struct sctp_ulpevent
*ev
;
2664 if (!sctp_vtag_verify(chunk
, asoc
))
2665 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2667 /* Make sure that the SHUTDOWN chunk has a valid length. */
2668 if (!sctp_chunk_length_valid(chunk
,
2669 sizeof(struct sctp_shutdown_chunk_t
)))
2670 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2673 /* Convert the elaborate header. */
2674 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2675 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2676 chunk
->subh
.shutdown_hdr
= sdh
;
2677 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2679 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2680 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2681 asoc
->ctsn_ack_point
);
2683 return SCTP_DISPOSITION_DISCARD
;
2686 /* If Cumulative TSN Ack beyond the max tsn currently
2687 * send, terminating the association and respond to the
2688 * sender with an ABORT.
2690 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2691 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2693 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2694 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2695 * inform the application that it should cease sending data.
2697 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2699 disposition
= SCTP_DISPOSITION_NOMEM
;
2702 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2704 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2705 * - enter the SHUTDOWN-RECEIVED state,
2706 * - stop accepting new data from its SCTP user
2708 * [This is implicit in the new state.]
2710 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2711 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2712 disposition
= SCTP_DISPOSITION_CONSUME
;
2714 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2715 disposition
= sctp_sf_do_9_2_shutdown_ack(net
, ep
, asoc
, type
,
2719 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2722 /* - verify, by checking the Cumulative TSN Ack field of the
2723 * chunk, that all its outstanding DATA chunks have been
2724 * received by the SHUTDOWN sender.
2726 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2727 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2734 * sctp_sf_do_9_2_shut_ctsn
2736 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2737 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2738 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2739 * MUST be processed.
2741 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(struct net
*net
,
2742 const struct sctp_endpoint
*ep
,
2743 const struct sctp_association
*asoc
,
2744 const sctp_subtype_t type
,
2746 sctp_cmd_seq_t
*commands
)
2748 struct sctp_chunk
*chunk
= arg
;
2749 sctp_shutdownhdr_t
*sdh
;
2752 if (!sctp_vtag_verify(chunk
, asoc
))
2753 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2755 /* Make sure that the SHUTDOWN chunk has a valid length. */
2756 if (!sctp_chunk_length_valid(chunk
,
2757 sizeof(struct sctp_shutdown_chunk_t
)))
2758 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2761 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2762 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2764 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2765 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2766 asoc
->ctsn_ack_point
);
2768 return SCTP_DISPOSITION_DISCARD
;
2771 /* If Cumulative TSN Ack beyond the max tsn currently
2772 * send, terminating the association and respond to the
2773 * sender with an ABORT.
2775 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2776 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2778 /* verify, by checking the Cumulative TSN Ack field of the
2779 * chunk, that all its outstanding DATA chunks have been
2780 * received by the SHUTDOWN sender.
2782 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2783 SCTP_BE32(sdh
->cum_tsn_ack
));
2785 return SCTP_DISPOSITION_CONSUME
;
2789 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2790 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2791 * transport addresses (either in the IP addresses or in the INIT chunk)
2792 * that belong to this association, it should discard the INIT chunk and
2793 * retransmit the SHUTDOWN ACK chunk.
2795 sctp_disposition_t
sctp_sf_do_9_2_reshutack(struct net
*net
,
2796 const struct sctp_endpoint
*ep
,
2797 const struct sctp_association
*asoc
,
2798 const sctp_subtype_t type
,
2800 sctp_cmd_seq_t
*commands
)
2802 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2803 struct sctp_chunk
*reply
;
2805 /* Make sure that the chunk has a valid length */
2806 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2807 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2810 /* Since we are not going to really process this INIT, there
2811 * is no point in verifying chunk boundries. Just generate
2814 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2818 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2819 * the T2-SHUTDOWN timer.
2821 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2823 /* and restart the T2-shutdown timer. */
2824 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2825 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2827 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2829 return SCTP_DISPOSITION_CONSUME
;
2831 return SCTP_DISPOSITION_NOMEM
;
2835 * sctp_sf_do_ecn_cwr
2837 * Section: Appendix A: Explicit Congestion Notification
2841 * RFC 2481 details a specific bit for a sender to send in the header of
2842 * its next outbound TCP segment to indicate to its peer that it has
2843 * reduced its congestion window. This is termed the CWR bit. For
2844 * SCTP the same indication is made by including the CWR chunk.
2845 * This chunk contains one data element, i.e. the TSN number that
2846 * was sent in the ECNE chunk. This element represents the lowest
2847 * TSN number in the datagram that was originally marked with the
2850 * Verification Tag: 8.5 Verification Tag [Normal verification]
2852 * (endpoint, asoc, chunk)
2855 * (asoc, reply_msg, msg_up, timers, counters)
2857 * The return value is the disposition of the chunk.
2859 sctp_disposition_t
sctp_sf_do_ecn_cwr(struct net
*net
,
2860 const struct sctp_endpoint
*ep
,
2861 const struct sctp_association
*asoc
,
2862 const sctp_subtype_t type
,
2864 sctp_cmd_seq_t
*commands
)
2867 struct sctp_chunk
*chunk
= arg
;
2870 if (!sctp_vtag_verify(chunk
, asoc
))
2871 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2873 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2874 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2877 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2878 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2880 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2882 /* Does this CWR ack the last sent congestion notification? */
2883 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2884 /* Stop sending ECNE. */
2885 sctp_add_cmd_sf(commands
,
2887 SCTP_U32(lowest_tsn
));
2889 return SCTP_DISPOSITION_CONSUME
;
2895 * Section: Appendix A: Explicit Congestion Notification
2899 * RFC 2481 details a specific bit for a receiver to send back in its
2900 * TCP acknowledgements to notify the sender of the Congestion
2901 * Experienced (CE) bit having arrived from the network. For SCTP this
2902 * same indication is made by including the ECNE chunk. This chunk
2903 * contains one data element, i.e. the lowest TSN associated with the IP
2904 * datagram marked with the CE bit.....
2906 * Verification Tag: 8.5 Verification Tag [Normal verification]
2908 * (endpoint, asoc, chunk)
2911 * (asoc, reply_msg, msg_up, timers, counters)
2913 * The return value is the disposition of the chunk.
2915 sctp_disposition_t
sctp_sf_do_ecne(struct net
*net
,
2916 const struct sctp_endpoint
*ep
,
2917 const struct sctp_association
*asoc
,
2918 const sctp_subtype_t type
,
2920 sctp_cmd_seq_t
*commands
)
2922 sctp_ecnehdr_t
*ecne
;
2923 struct sctp_chunk
*chunk
= arg
;
2925 if (!sctp_vtag_verify(chunk
, asoc
))
2926 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2928 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2929 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2932 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2933 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2935 /* If this is a newer ECNE than the last CWR packet we sent out */
2936 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2937 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2939 return SCTP_DISPOSITION_CONSUME
;
2943 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2945 * The SCTP endpoint MUST always acknowledge the reception of each valid
2948 * The guidelines on delayed acknowledgement algorithm specified in
2949 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2950 * acknowledgement SHOULD be generated for at least every second packet
2951 * (not every second DATA chunk) received, and SHOULD be generated within
2952 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2953 * situations it may be beneficial for an SCTP transmitter to be more
2954 * conservative than the algorithms detailed in this document allow.
2955 * However, an SCTP transmitter MUST NOT be more aggressive than the
2956 * following algorithms allow.
2958 * A SCTP receiver MUST NOT generate more than one SACK for every
2959 * incoming packet, other than to update the offered window as the
2960 * receiving application consumes new data.
2962 * Verification Tag: 8.5 Verification Tag [Normal verification]
2965 * (endpoint, asoc, chunk)
2968 * (asoc, reply_msg, msg_up, timers, counters)
2970 * The return value is the disposition of the chunk.
2972 sctp_disposition_t
sctp_sf_eat_data_6_2(struct net
*net
,
2973 const struct sctp_endpoint
*ep
,
2974 const struct sctp_association
*asoc
,
2975 const sctp_subtype_t type
,
2977 sctp_cmd_seq_t
*commands
)
2979 struct sctp_chunk
*chunk
= arg
;
2980 sctp_arg_t force
= SCTP_NOFORCE();
2983 if (!sctp_vtag_verify(chunk
, asoc
)) {
2984 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2986 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2989 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2990 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2993 error
= sctp_eat_data(asoc
, chunk
, commands
);
2995 case SCTP_IERROR_NO_ERROR
:
2997 case SCTP_IERROR_HIGH_TSN
:
2998 case SCTP_IERROR_BAD_STREAM
:
2999 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
3000 goto discard_noforce
;
3001 case SCTP_IERROR_DUP_TSN
:
3002 case SCTP_IERROR_IGNORE_TSN
:
3003 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
3005 case SCTP_IERROR_NO_DATA
:
3006 return SCTP_DISPOSITION_ABORT
;
3007 case SCTP_IERROR_PROTO_VIOLATION
:
3008 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
3009 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3014 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
3015 force
= SCTP_FORCE();
3017 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
3018 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3019 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3022 /* If this is the last chunk in a packet, we need to count it
3023 * toward sack generation. Note that we need to SACK every
3024 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3025 * THEM. We elect to NOT generate SACK's if the chunk fails
3026 * the verification tag test.
3028 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3030 * The SCTP endpoint MUST always acknowledge the reception of
3031 * each valid DATA chunk.
3033 * The guidelines on delayed acknowledgement algorithm
3034 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3035 * Specifically, an acknowledgement SHOULD be generated for at
3036 * least every second packet (not every second DATA chunk)
3037 * received, and SHOULD be generated within 200 ms of the
3038 * arrival of any unacknowledged DATA chunk. In some
3039 * situations it may be beneficial for an SCTP transmitter to
3040 * be more conservative than the algorithms detailed in this
3041 * document allow. However, an SCTP transmitter MUST NOT be
3042 * more aggressive than the following algorithms allow.
3044 if (chunk
->end_of_packet
)
3045 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3047 return SCTP_DISPOSITION_CONSUME
;
3050 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3052 * When a packet arrives with duplicate DATA chunk(s) and with
3053 * no new DATA chunk(s), the endpoint MUST immediately send a
3054 * SACK with no delay. If a packet arrives with duplicate
3055 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3056 * MAY immediately send a SACK. Normally receipt of duplicate
3057 * DATA chunks will occur when the original SACK chunk was lost
3058 * and the peer's RTO has expired. The duplicate TSN number(s)
3059 * SHOULD be reported in the SACK as duplicate.
3061 /* In our case, we split the MAY SACK advice up whether or not
3062 * the last chunk is a duplicate.'
3064 if (chunk
->end_of_packet
)
3065 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3066 return SCTP_DISPOSITION_DISCARD
;
3069 if (chunk
->end_of_packet
)
3070 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3072 return SCTP_DISPOSITION_DISCARD
;
3076 * sctp_sf_eat_data_fast_4_4
3079 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3080 * DATA chunks without delay.
3082 * Verification Tag: 8.5 Verification Tag [Normal verification]
3084 * (endpoint, asoc, chunk)
3087 * (asoc, reply_msg, msg_up, timers, counters)
3089 * The return value is the disposition of the chunk.
3091 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(struct net
*net
,
3092 const struct sctp_endpoint
*ep
,
3093 const struct sctp_association
*asoc
,
3094 const sctp_subtype_t type
,
3096 sctp_cmd_seq_t
*commands
)
3098 struct sctp_chunk
*chunk
= arg
;
3101 if (!sctp_vtag_verify(chunk
, asoc
)) {
3102 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3104 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3107 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
3108 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3111 error
= sctp_eat_data(asoc
, chunk
, commands
);
3113 case SCTP_IERROR_NO_ERROR
:
3114 case SCTP_IERROR_HIGH_TSN
:
3115 case SCTP_IERROR_DUP_TSN
:
3116 case SCTP_IERROR_IGNORE_TSN
:
3117 case SCTP_IERROR_BAD_STREAM
:
3119 case SCTP_IERROR_NO_DATA
:
3120 return SCTP_DISPOSITION_ABORT
;
3121 case SCTP_IERROR_PROTO_VIOLATION
:
3122 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
3123 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3128 /* Go a head and force a SACK, since we are shutting down. */
3130 /* Implementor's Guide.
3132 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3133 * respond to each received packet containing one or more DATA chunk(s)
3134 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3136 if (chunk
->end_of_packet
) {
3137 /* We must delay the chunk creation since the cumulative
3138 * TSN has not been updated yet.
3140 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3141 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3142 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3143 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3146 return SCTP_DISPOSITION_CONSUME
;
3150 * Section: 6.2 Processing a Received SACK
3151 * D) Any time a SACK arrives, the endpoint performs the following:
3153 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3154 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3155 * increasing, a SACK whose Cumulative TSN Ack is less than the
3156 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3158 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3159 * of bytes still outstanding after processing the Cumulative TSN Ack
3160 * and the Gap Ack Blocks.
3162 * iii) If the SACK is missing a TSN that was previously
3163 * acknowledged via a Gap Ack Block (e.g., the data receiver
3164 * reneged on the data), then mark the corresponding DATA chunk
3165 * as available for retransmit: Mark it as missing for fast
3166 * retransmit as described in Section 7.2.4 and if no retransmit
3167 * timer is running for the destination address to which the DATA
3168 * chunk was originally transmitted, then T3-rtx is started for
3169 * that destination address.
3171 * Verification Tag: 8.5 Verification Tag [Normal verification]
3174 * (endpoint, asoc, chunk)
3177 * (asoc, reply_msg, msg_up, timers, counters)
3179 * The return value is the disposition of the chunk.
3181 sctp_disposition_t
sctp_sf_eat_sack_6_2(struct net
*net
,
3182 const struct sctp_endpoint
*ep
,
3183 const struct sctp_association
*asoc
,
3184 const sctp_subtype_t type
,
3186 sctp_cmd_seq_t
*commands
)
3188 struct sctp_chunk
*chunk
= arg
;
3189 sctp_sackhdr_t
*sackh
;
3192 if (!sctp_vtag_verify(chunk
, asoc
))
3193 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3195 /* Make sure that the SACK chunk has a valid length. */
3196 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3197 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3200 /* Pull the SACK chunk from the data buffer */
3201 sackh
= sctp_sm_pull_sack(chunk
);
3202 /* Was this a bogus SACK? */
3204 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3205 chunk
->subh
.sack_hdr
= sackh
;
3206 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3208 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3209 * Ack Point, then drop the SACK. Since Cumulative TSN
3210 * Ack is monotonically increasing, a SACK whose
3211 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3212 * Point indicates an out-of-order SACK.
3214 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3215 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
3216 asoc
->ctsn_ack_point
);
3218 return SCTP_DISPOSITION_DISCARD
;
3221 /* If Cumulative TSN Ack beyond the max tsn currently
3222 * send, terminating the association and respond to the
3223 * sender with an ABORT.
3225 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3226 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
3228 /* Return this SACK for further processing. */
3229 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_CHUNK(chunk
));
3231 /* Note: We do the rest of the work on the PROCESS_SACK
3234 return SCTP_DISPOSITION_CONSUME
;
3238 * Generate an ABORT in response to a packet.
3240 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3242 * 8) The receiver should respond to the sender of the OOTB packet with
3243 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3244 * MUST fill in the Verification Tag field of the outbound packet
3245 * with the value found in the Verification Tag field of the OOTB
3246 * packet and set the T-bit in the Chunk Flags to indicate that the
3247 * Verification Tag is reflected. After sending this ABORT, the
3248 * receiver of the OOTB packet shall discard the OOTB packet and take
3249 * no further action.
3253 * The return value is the disposition of the chunk.
3255 static sctp_disposition_t
sctp_sf_tabort_8_4_8(struct net
*net
,
3256 const struct sctp_endpoint
*ep
,
3257 const struct sctp_association
*asoc
,
3258 const sctp_subtype_t type
,
3260 sctp_cmd_seq_t
*commands
)
3262 struct sctp_packet
*packet
= NULL
;
3263 struct sctp_chunk
*chunk
= arg
;
3264 struct sctp_chunk
*abort
;
3266 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3268 return SCTP_DISPOSITION_NOMEM
;
3270 /* Make an ABORT. The T bit will be set if the asoc
3273 abort
= sctp_make_abort(asoc
, chunk
, 0);
3275 sctp_ootb_pkt_free(packet
);
3276 return SCTP_DISPOSITION_NOMEM
;
3279 /* Reflect vtag if T-Bit is set */
3280 if (sctp_test_T_bit(abort
))
3281 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3283 /* Set the skb to the belonging sock for accounting. */
3284 abort
->skb
->sk
= ep
->base
.sk
;
3286 sctp_packet_append_chunk(packet
, abort
);
3288 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3289 SCTP_PACKET(packet
));
3291 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3293 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3294 return SCTP_DISPOSITION_CONSUME
;
3298 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3299 * event as ULP notification for each cause included in the chunk.
3301 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3303 * The return value is the disposition of the chunk.
3305 sctp_disposition_t
sctp_sf_operr_notify(struct net
*net
,
3306 const struct sctp_endpoint
*ep
,
3307 const struct sctp_association
*asoc
,
3308 const sctp_subtype_t type
,
3310 sctp_cmd_seq_t
*commands
)
3312 struct sctp_chunk
*chunk
= arg
;
3315 if (!sctp_vtag_verify(chunk
, asoc
))
3316 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3318 /* Make sure that the ERROR chunk has a valid length. */
3319 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3320 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3322 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3323 if ((void *)err
!= (void *)chunk
->chunk_end
)
3324 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3325 (void *)err
, commands
);
3327 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3330 return SCTP_DISPOSITION_CONSUME
;
3334 * Process an inbound SHUTDOWN ACK.
3337 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3338 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3339 * peer, and remove all record of the association.
3341 * The return value is the disposition.
3343 sctp_disposition_t
sctp_sf_do_9_2_final(struct net
*net
,
3344 const struct sctp_endpoint
*ep
,
3345 const struct sctp_association
*asoc
,
3346 const sctp_subtype_t type
,
3348 sctp_cmd_seq_t
*commands
)
3350 struct sctp_chunk
*chunk
= arg
;
3351 struct sctp_chunk
*reply
;
3352 struct sctp_ulpevent
*ev
;
3354 if (!sctp_vtag_verify(chunk
, asoc
))
3355 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3357 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3358 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3359 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3361 /* 10.2 H) SHUTDOWN COMPLETE notification
3363 * When SCTP completes the shutdown procedures (section 9.2) this
3364 * notification is passed to the upper layer.
3366 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3367 0, 0, 0, NULL
, GFP_ATOMIC
);
3371 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3372 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3376 /* Do all the commands now (after allocation), so that we
3377 * have consistent state if memory allocation failes
3379 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3381 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3382 * stop the T2-shutdown timer,
3384 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3385 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3387 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3388 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3390 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3391 SCTP_STATE(SCTP_STATE_CLOSED
));
3392 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
3393 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3394 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3396 /* ...and remove all record of the association. */
3397 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3398 return SCTP_DISPOSITION_DELETE_TCB
;
3401 sctp_ulpevent_free(ev
);
3403 return SCTP_DISPOSITION_NOMEM
;
3407 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3409 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3410 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3411 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3412 * packet must fill in the Verification Tag field of the outbound
3413 * packet with the Verification Tag received in the SHUTDOWN ACK and
3414 * set the T-bit in the Chunk Flags to indicate that the Verification
3417 * 8) The receiver should respond to the sender of the OOTB packet with
3418 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3419 * MUST fill in the Verification Tag field of the outbound packet
3420 * with the value found in the Verification Tag field of the OOTB
3421 * packet and set the T-bit in the Chunk Flags to indicate that the
3422 * Verification Tag is reflected. After sending this ABORT, the
3423 * receiver of the OOTB packet shall discard the OOTB packet and take
3424 * no further action.
3426 sctp_disposition_t
sctp_sf_ootb(struct net
*net
,
3427 const struct sctp_endpoint
*ep
,
3428 const struct sctp_association
*asoc
,
3429 const sctp_subtype_t type
,
3431 sctp_cmd_seq_t
*commands
)
3433 struct sctp_chunk
*chunk
= arg
;
3434 struct sk_buff
*skb
= chunk
->skb
;
3435 sctp_chunkhdr_t
*ch
;
3438 int ootb_shut_ack
= 0;
3439 int ootb_cookie_ack
= 0;
3441 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3443 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3445 /* Report violation if the chunk is less then minimal */
3446 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3447 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3450 /* Report violation if chunk len overflows */
3451 ch_end
= ((__u8
*)ch
) + SCTP_PAD4(ntohs(ch
->length
));
3452 if (ch_end
> skb_tail_pointer(skb
))
3453 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3456 /* Now that we know we at least have a chunk header,
3457 * do things that are type appropriate.
3459 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3462 /* RFC 2960, Section 3.3.7
3463 * Moreover, under any circumstances, an endpoint that
3464 * receives an ABORT MUST NOT respond to that ABORT by
3465 * sending an ABORT of its own.
3467 if (SCTP_CID_ABORT
== ch
->type
)
3468 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3470 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3471 * or a COOKIE ACK the SCTP Packet should be silently
3475 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
3476 ootb_cookie_ack
= 1;
3478 if (SCTP_CID_ERROR
== ch
->type
) {
3479 sctp_walk_errors(err
, ch
) {
3480 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
) {
3481 ootb_cookie_ack
= 1;
3487 ch
= (sctp_chunkhdr_t
*) ch_end
;
3488 } while (ch_end
< skb_tail_pointer(skb
));
3491 return sctp_sf_shut_8_4_5(net
, ep
, asoc
, type
, arg
, commands
);
3492 else if (ootb_cookie_ack
)
3493 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3495 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
3499 * Handle an "Out of the blue" SHUTDOWN ACK.
3501 * Section: 8.4 5, sctpimpguide 2.41.
3503 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3504 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3505 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3506 * packet must fill in the Verification Tag field of the outbound
3507 * packet with the Verification Tag received in the SHUTDOWN ACK and
3508 * set the T-bit in the Chunk Flags to indicate that the Verification
3512 * (endpoint, asoc, type, arg, commands)
3515 * (sctp_disposition_t)
3517 * The return value is the disposition of the chunk.
3519 static sctp_disposition_t
sctp_sf_shut_8_4_5(struct net
*net
,
3520 const struct sctp_endpoint
*ep
,
3521 const struct sctp_association
*asoc
,
3522 const sctp_subtype_t type
,
3524 sctp_cmd_seq_t
*commands
)
3526 struct sctp_packet
*packet
= NULL
;
3527 struct sctp_chunk
*chunk
= arg
;
3528 struct sctp_chunk
*shut
;
3530 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3532 return SCTP_DISPOSITION_NOMEM
;
3534 /* Make an SHUTDOWN_COMPLETE.
3535 * The T bit will be set if the asoc is NULL.
3537 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3539 sctp_ootb_pkt_free(packet
);
3540 return SCTP_DISPOSITION_NOMEM
;
3543 /* Reflect vtag if T-Bit is set */
3544 if (sctp_test_T_bit(shut
))
3545 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3547 /* Set the skb to the belonging sock for accounting. */
3548 shut
->skb
->sk
= ep
->base
.sk
;
3550 sctp_packet_append_chunk(packet
, shut
);
3552 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3553 SCTP_PACKET(packet
));
3555 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3557 /* If the chunk length is invalid, we don't want to process
3558 * the reset of the packet.
3560 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3561 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3563 /* We need to discard the rest of the packet to prevent
3564 * potential bomming attacks from additional bundled chunks.
3565 * This is documented in SCTP Threats ID.
3567 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3571 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3573 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3574 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3575 * procedures in section 8.4 SHOULD be followed, in other words it
3576 * should be treated as an Out Of The Blue packet.
3577 * [This means that we do NOT check the Verification Tag on these
3581 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(struct net
*net
,
3582 const struct sctp_endpoint
*ep
,
3583 const struct sctp_association
*asoc
,
3584 const sctp_subtype_t type
,
3586 sctp_cmd_seq_t
*commands
)
3588 struct sctp_chunk
*chunk
= arg
;
3590 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3591 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3592 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3595 /* Although we do have an association in this case, it corresponds
3596 * to a restarted association. So the packet is treated as an OOTB
3597 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3598 * called with a NULL association.
3600 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3602 return sctp_sf_shut_8_4_5(net
, ep
, NULL
, type
, arg
, commands
);
3605 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3606 sctp_disposition_t
sctp_sf_do_asconf(struct net
*net
,
3607 const struct sctp_endpoint
*ep
,
3608 const struct sctp_association
*asoc
,
3609 const sctp_subtype_t type
, void *arg
,
3610 sctp_cmd_seq_t
*commands
)
3612 struct sctp_chunk
*chunk
= arg
;
3613 struct sctp_chunk
*asconf_ack
= NULL
;
3614 struct sctp_paramhdr
*err_param
= NULL
;
3615 sctp_addiphdr_t
*hdr
;
3618 if (!sctp_vtag_verify(chunk
, asoc
)) {
3619 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3621 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3624 /* ADD-IP: Section 4.1.1
3625 * This chunk MUST be sent in an authenticated way by using
3626 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3627 * is received unauthenticated it MUST be silently discarded as
3628 * described in [I-D.ietf-tsvwg-sctp-auth].
3630 if (!net
->sctp
.addip_noauth
&& !chunk
->auth
)
3631 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3633 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3634 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3635 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3638 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3639 serial
= ntohl(hdr
->serial
);
3641 /* Verify the ASCONF chunk before processing it. */
3642 if (!sctp_verify_asconf(asoc
, chunk
, true, &err_param
))
3643 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3644 (void *)err_param
, commands
);
3646 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3647 * the endpoint stored in a new association variable
3648 * 'Peer-Serial-Number'.
3650 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3651 /* If this is the first instance of ASCONF in the packet,
3652 * we can clean our old ASCONF-ACKs.
3654 if (!chunk
->has_asconf
)
3655 sctp_assoc_clean_asconf_ack_cache(asoc
);
3657 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3658 * expected, process the ASCONF as described below and after
3659 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3660 * the response packet and cache a copy of it (in the event it
3661 * later needs to be retransmitted).
3663 * Essentially, do V1-V5.
3665 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3668 return SCTP_DISPOSITION_NOMEM
;
3669 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3671 * If the value found in the Sequence Number is less than the
3672 * ('Peer- Sequence-Number' + 1), simply skip to the next
3673 * ASCONF, and include in the outbound response packet
3674 * any previously cached ASCONF-ACK response that was
3675 * sent and saved that matches the Sequence Number of the
3676 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3677 * Chunk exists. This will occur when an older ASCONF
3678 * arrives out of order. In such a case, the receiver
3679 * should skip the ASCONF Chunk and not include ASCONF-ACK
3680 * Chunk for that chunk.
3682 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3684 return SCTP_DISPOSITION_DISCARD
;
3686 /* Reset the transport so that we select the correct one
3687 * this time around. This is to make sure that we don't
3688 * accidentally use a stale transport that's been removed.
3690 asconf_ack
->transport
= NULL
;
3692 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3693 * it must be either a stale packet or from an attacker.
3695 return SCTP_DISPOSITION_DISCARD
;
3698 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3699 * containing the ASCONF-ACK Chunks MUST be the source address of
3700 * the SCTP packet that held the ASCONF Chunks.
3702 * To do this properly, we'll set the destination address of the chunk
3703 * and at the transmit time, will try look up the transport to use.
3704 * Since ASCONFs may be bundled, the correct transport may not be
3705 * created until we process the entire packet, thus this workaround.
3707 asconf_ack
->dest
= chunk
->source
;
3708 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3709 if (asoc
->new_transport
) {
3710 sctp_sf_heartbeat(ep
, asoc
, type
, asoc
->new_transport
, commands
);
3711 ((struct sctp_association
*)asoc
)->new_transport
= NULL
;
3714 return SCTP_DISPOSITION_CONSUME
;
3718 * ADDIP Section 4.3 General rules for address manipulation
3719 * When building TLV parameters for the ASCONF Chunk that will add or
3720 * delete IP addresses the D0 to D13 rules should be applied:
3722 sctp_disposition_t
sctp_sf_do_asconf_ack(struct net
*net
,
3723 const struct sctp_endpoint
*ep
,
3724 const struct sctp_association
*asoc
,
3725 const sctp_subtype_t type
, void *arg
,
3726 sctp_cmd_seq_t
*commands
)
3728 struct sctp_chunk
*asconf_ack
= arg
;
3729 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3730 struct sctp_chunk
*abort
;
3731 struct sctp_paramhdr
*err_param
= NULL
;
3732 sctp_addiphdr_t
*addip_hdr
;
3733 __u32 sent_serial
, rcvd_serial
;
3735 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3736 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3738 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3741 /* ADD-IP, Section 4.1.2:
3742 * This chunk MUST be sent in an authenticated way by using
3743 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3744 * is received unauthenticated it MUST be silently discarded as
3745 * described in [I-D.ietf-tsvwg-sctp-auth].
3747 if (!net
->sctp
.addip_noauth
&& !asconf_ack
->auth
)
3748 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3750 /* Make sure that the ADDIP chunk has a valid length. */
3751 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3752 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3755 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3756 rcvd_serial
= ntohl(addip_hdr
->serial
);
3758 /* Verify the ASCONF-ACK chunk before processing it. */
3759 if (!sctp_verify_asconf(asoc
, asconf_ack
, false, &err_param
))
3760 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3761 (void *)err_param
, commands
);
3764 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3765 sent_serial
= ntohl(addip_hdr
->serial
);
3767 sent_serial
= asoc
->addip_serial
- 1;
3770 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3771 * equal to the next serial number to be used but no ASCONF chunk is
3772 * outstanding the endpoint MUST ABORT the association. Note that a
3773 * sequence number is greater than if it is no more than 2^^31-1
3774 * larger than the current sequence number (using serial arithmetic).
3776 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3777 !(asoc
->addip_last_asconf
)) {
3778 abort
= sctp_make_abort(asoc
, asconf_ack
,
3779 sizeof(sctp_errhdr_t
));
3781 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3782 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3785 /* We are going to ABORT, so we might as well stop
3786 * processing the rest of the chunks in the packet.
3788 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3789 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3790 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3791 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3792 SCTP_ERROR(ECONNABORTED
));
3793 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3794 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3795 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3796 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3797 return SCTP_DISPOSITION_ABORT
;
3800 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3801 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3802 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3804 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3806 /* Successfully processed ASCONF_ACK. We can
3807 * release the next asconf if we have one.
3809 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3811 return SCTP_DISPOSITION_CONSUME
;
3814 abort
= sctp_make_abort(asoc
, asconf_ack
,
3815 sizeof(sctp_errhdr_t
));
3817 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3818 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3821 /* We are going to ABORT, so we might as well stop
3822 * processing the rest of the chunks in the packet.
3824 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3825 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3826 SCTP_ERROR(ECONNABORTED
));
3827 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3828 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3829 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3830 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3831 return SCTP_DISPOSITION_ABORT
;
3834 return SCTP_DISPOSITION_DISCARD
;
3838 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3840 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3841 * its cumulative TSN point to the value carried in the FORWARD TSN
3842 * chunk, and then MUST further advance its cumulative TSN point locally
3844 * After the above processing, the data receiver MUST stop reporting any
3845 * missing TSNs earlier than or equal to the new cumulative TSN point.
3847 * Verification Tag: 8.5 Verification Tag [Normal verification]
3849 * The return value is the disposition of the chunk.
3851 sctp_disposition_t
sctp_sf_eat_fwd_tsn(struct net
*net
,
3852 const struct sctp_endpoint
*ep
,
3853 const struct sctp_association
*asoc
,
3854 const sctp_subtype_t type
,
3856 sctp_cmd_seq_t
*commands
)
3858 struct sctp_chunk
*chunk
= arg
;
3859 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3860 struct sctp_fwdtsn_skip
*skip
;
3864 if (!sctp_vtag_verify(chunk
, asoc
)) {
3865 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3867 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3870 if (!asoc
->peer
.prsctp_capable
)
3871 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3873 /* Make sure that the FORWARD_TSN chunk has valid length. */
3874 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3875 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3878 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3879 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3880 len
= ntohs(chunk
->chunk_hdr
->length
);
3881 len
-= sizeof(struct sctp_chunkhdr
);
3882 skb_pull(chunk
->skb
, len
);
3884 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3885 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
3887 /* The TSN is too high--silently discard the chunk and count on it
3888 * getting retransmitted later.
3890 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3891 goto discard_noforce
;
3893 /* Silently discard the chunk if stream-id is not valid */
3894 sctp_walk_fwdtsn(skip
, chunk
) {
3895 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3896 goto discard_noforce
;
3899 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3900 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3901 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3904 /* Count this as receiving DATA. */
3905 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
3906 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3907 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3910 /* FIXME: For now send a SACK, but DATA processing may
3913 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3915 return SCTP_DISPOSITION_CONSUME
;
3918 return SCTP_DISPOSITION_DISCARD
;
3921 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3923 const struct sctp_endpoint
*ep
,
3924 const struct sctp_association
*asoc
,
3925 const sctp_subtype_t type
,
3927 sctp_cmd_seq_t
*commands
)
3929 struct sctp_chunk
*chunk
= arg
;
3930 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3931 struct sctp_fwdtsn_skip
*skip
;
3935 if (!sctp_vtag_verify(chunk
, asoc
)) {
3936 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3938 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3941 if (!asoc
->peer
.prsctp_capable
)
3942 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3944 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3945 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3946 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3949 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3950 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3951 len
= ntohs(chunk
->chunk_hdr
->length
);
3952 len
-= sizeof(struct sctp_chunkhdr
);
3953 skb_pull(chunk
->skb
, len
);
3955 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3956 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
3958 /* The TSN is too high--silently discard the chunk and count on it
3959 * getting retransmitted later.
3961 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3964 /* Silently discard the chunk if stream-id is not valid */
3965 sctp_walk_fwdtsn(skip
, chunk
) {
3966 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3970 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3971 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3972 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3975 /* Go a head and force a SACK, since we are shutting down. */
3977 /* Implementor's Guide.
3979 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3980 * respond to each received packet containing one or more DATA chunk(s)
3981 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3983 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3984 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3985 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3986 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3988 return SCTP_DISPOSITION_CONSUME
;
3992 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3994 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3995 * Identifier field. If this algorithm was not specified by the
3996 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3997 * during association setup, the AUTH chunk and all chunks after it MUST
3998 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3999 * defined in Section 4.1.
4001 * If an endpoint with no shared key receives a Shared Key Identifier
4002 * other than 0, it MUST silently discard all authenticated chunks. If
4003 * the endpoint has at least one endpoint pair shared key for the peer,
4004 * it MUST use the key specified by the Shared Key Identifier if a
4005 * key has been configured for that Shared Key Identifier. If no
4006 * endpoint pair shared key has been configured for that Shared Key
4007 * Identifier, all authenticated chunks MUST be silently discarded.
4009 * Verification Tag: 8.5 Verification Tag [Normal verification]
4011 * The return value is the disposition of the chunk.
4013 static sctp_ierror_t
sctp_sf_authenticate(struct net
*net
,
4014 const struct sctp_endpoint
*ep
,
4015 const struct sctp_association
*asoc
,
4016 const sctp_subtype_t type
,
4017 struct sctp_chunk
*chunk
)
4019 struct sctp_authhdr
*auth_hdr
;
4020 struct sctp_hmac
*hmac
;
4021 unsigned int sig_len
;
4026 /* Pull in the auth header, so we can do some more verification */
4027 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4028 chunk
->subh
.auth_hdr
= auth_hdr
;
4029 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
4031 /* Make sure that we support the HMAC algorithm from the auth
4034 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
4035 return SCTP_IERROR_AUTH_BAD_HMAC
;
4037 /* Make sure that the provided shared key identifier has been
4040 key_id
= ntohs(auth_hdr
->shkey_id
);
4041 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
4042 return SCTP_IERROR_AUTH_BAD_KEYID
;
4045 /* Make sure that the length of the signature matches what
4048 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
4049 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
4050 if (sig_len
!= hmac
->hmac_len
)
4051 return SCTP_IERROR_PROTO_VIOLATION
;
4053 /* Now that we've done validation checks, we can compute and
4054 * verify the hmac. The steps involved are:
4055 * 1. Save the digest from the chunk.
4056 * 2. Zero out the digest in the chunk.
4057 * 3. Compute the new digest
4058 * 4. Compare saved and new digests.
4060 digest
= auth_hdr
->hmac
;
4061 skb_pull(chunk
->skb
, sig_len
);
4063 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
4067 memset(digest
, 0, sig_len
);
4069 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
4070 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
4073 /* Discard the packet if the digests do not match */
4074 if (memcmp(save_digest
, digest
, sig_len
)) {
4076 return SCTP_IERROR_BAD_SIG
;
4082 return SCTP_IERROR_NO_ERROR
;
4084 return SCTP_IERROR_NOMEM
;
4087 sctp_disposition_t
sctp_sf_eat_auth(struct net
*net
,
4088 const struct sctp_endpoint
*ep
,
4089 const struct sctp_association
*asoc
,
4090 const sctp_subtype_t type
,
4092 sctp_cmd_seq_t
*commands
)
4094 struct sctp_authhdr
*auth_hdr
;
4095 struct sctp_chunk
*chunk
= arg
;
4096 struct sctp_chunk
*err_chunk
;
4097 sctp_ierror_t error
;
4099 /* Make sure that the peer has AUTH capable */
4100 if (!asoc
->peer
.auth_capable
)
4101 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
4103 if (!sctp_vtag_verify(chunk
, asoc
)) {
4104 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
4106 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4109 /* Make sure that the AUTH chunk has valid length. */
4110 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
4111 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4114 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4115 error
= sctp_sf_authenticate(net
, ep
, asoc
, type
, chunk
);
4117 case SCTP_IERROR_AUTH_BAD_HMAC
:
4118 /* Generate the ERROR chunk and discard the rest
4121 err_chunk
= sctp_make_op_error(asoc
, chunk
,
4122 SCTP_ERROR_UNSUP_HMAC
,
4126 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4127 SCTP_CHUNK(err_chunk
));
4130 case SCTP_IERROR_AUTH_BAD_KEYID
:
4131 case SCTP_IERROR_BAD_SIG
:
4132 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4134 case SCTP_IERROR_PROTO_VIOLATION
:
4135 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4138 case SCTP_IERROR_NOMEM
:
4139 return SCTP_DISPOSITION_NOMEM
;
4141 default: /* Prevent gcc warnings */
4145 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4146 struct sctp_ulpevent
*ev
;
4148 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4149 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4154 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4158 return SCTP_DISPOSITION_CONSUME
;
4162 * Process an unknown chunk.
4164 * Section: 3.2. Also, 2.1 in the implementor's guide.
4166 * Chunk Types are encoded such that the highest-order two bits specify
4167 * the action that must be taken if the processing endpoint does not
4168 * recognize the Chunk Type.
4170 * 00 - Stop processing this SCTP packet and discard it, do not process
4171 * any further chunks within it.
4173 * 01 - Stop processing this SCTP packet and discard it, do not process
4174 * any further chunks within it, and report the unrecognized
4175 * chunk in an 'Unrecognized Chunk Type'.
4177 * 10 - Skip this chunk and continue processing.
4179 * 11 - Skip this chunk and continue processing, but report in an ERROR
4180 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4182 * The return value is the disposition of the chunk.
4184 sctp_disposition_t
sctp_sf_unk_chunk(struct net
*net
,
4185 const struct sctp_endpoint
*ep
,
4186 const struct sctp_association
*asoc
,
4187 const sctp_subtype_t type
,
4189 sctp_cmd_seq_t
*commands
)
4191 struct sctp_chunk
*unk_chunk
= arg
;
4192 struct sctp_chunk
*err_chunk
;
4193 sctp_chunkhdr_t
*hdr
;
4195 pr_debug("%s: processing unknown chunk id:%d\n", __func__
, type
.chunk
);
4197 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4198 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4200 /* Make sure that the chunk has a valid length.
4201 * Since we don't know the chunk type, we use a general
4202 * chunkhdr structure to make a comparison.
4204 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
4205 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4208 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4209 case SCTP_CID_ACTION_DISCARD
:
4210 /* Discard the packet. */
4211 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4212 case SCTP_CID_ACTION_DISCARD_ERR
:
4213 /* Generate an ERROR chunk as response. */
4214 hdr
= unk_chunk
->chunk_hdr
;
4215 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4216 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4217 SCTP_PAD4(ntohs(hdr
->length
)),
4220 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4221 SCTP_CHUNK(err_chunk
));
4224 /* Discard the packet. */
4225 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4226 return SCTP_DISPOSITION_CONSUME
;
4227 case SCTP_CID_ACTION_SKIP
:
4228 /* Skip the chunk. */
4229 return SCTP_DISPOSITION_DISCARD
;
4230 case SCTP_CID_ACTION_SKIP_ERR
:
4231 /* Generate an ERROR chunk as response. */
4232 hdr
= unk_chunk
->chunk_hdr
;
4233 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4234 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4235 SCTP_PAD4(ntohs(hdr
->length
)),
4238 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4239 SCTP_CHUNK(err_chunk
));
4241 /* Skip the chunk. */
4242 return SCTP_DISPOSITION_CONSUME
;
4247 return SCTP_DISPOSITION_DISCARD
;
4251 * Discard the chunk.
4253 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4254 * [Too numerous to mention...]
4255 * Verification Tag: No verification needed.
4257 * (endpoint, asoc, chunk)
4260 * (asoc, reply_msg, msg_up, timers, counters)
4262 * The return value is the disposition of the chunk.
4264 sctp_disposition_t
sctp_sf_discard_chunk(struct net
*net
,
4265 const struct sctp_endpoint
*ep
,
4266 const struct sctp_association
*asoc
,
4267 const sctp_subtype_t type
,
4269 sctp_cmd_seq_t
*commands
)
4271 struct sctp_chunk
*chunk
= arg
;
4273 /* Make sure that the chunk has a valid length.
4274 * Since we don't know the chunk type, we use a general
4275 * chunkhdr structure to make a comparison.
4277 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4278 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4281 pr_debug("%s: chunk:%d is discarded\n", __func__
, type
.chunk
);
4283 return SCTP_DISPOSITION_DISCARD
;
4287 * Discard the whole packet.
4291 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4292 * silently discard the OOTB packet and take no further action.
4294 * Verification Tag: No verification necessary
4297 * (endpoint, asoc, chunk)
4300 * (asoc, reply_msg, msg_up, timers, counters)
4302 * The return value is the disposition of the chunk.
4304 sctp_disposition_t
sctp_sf_pdiscard(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 SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_DISCARDS
);
4312 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4314 return SCTP_DISPOSITION_CONSUME
;
4319 * The other end is violating protocol.
4321 * Section: Not specified
4322 * Verification Tag: Not specified
4324 * (endpoint, asoc, chunk)
4327 * (asoc, reply_msg, msg_up, timers, counters)
4329 * We simply tag the chunk as a violation. The state machine will log
4330 * the violation and continue.
4332 sctp_disposition_t
sctp_sf_violation(struct net
*net
,
4333 const struct sctp_endpoint
*ep
,
4334 const struct sctp_association
*asoc
,
4335 const sctp_subtype_t type
,
4337 sctp_cmd_seq_t
*commands
)
4339 struct sctp_chunk
*chunk
= arg
;
4341 /* Make sure that the chunk has a valid length. */
4342 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4343 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4346 return SCTP_DISPOSITION_VIOLATION
;
4350 * Common function to handle a protocol violation.
4352 static sctp_disposition_t
sctp_sf_abort_violation(
4354 const struct sctp_endpoint
*ep
,
4355 const struct sctp_association
*asoc
,
4357 sctp_cmd_seq_t
*commands
,
4358 const __u8
*payload
,
4359 const size_t paylen
)
4361 struct sctp_packet
*packet
= NULL
;
4362 struct sctp_chunk
*chunk
= arg
;
4363 struct sctp_chunk
*abort
= NULL
;
4365 /* SCTP-AUTH, Section 6.3:
4366 * It should be noted that if the receiver wants to tear
4367 * down an association in an authenticated way only, the
4368 * handling of malformed packets should not result in
4369 * tearing down the association.
4371 * This means that if we only want to abort associations
4372 * in an authenticated way (i.e AUTH+ABORT), then we
4373 * can't destroy this association just because the packet
4376 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4379 /* Make the abort chunk. */
4380 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4385 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4386 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4387 !asoc
->peer
.i
.init_tag
) {
4388 sctp_initack_chunk_t
*initack
;
4390 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4391 if (!sctp_chunk_length_valid(chunk
,
4392 sizeof(sctp_initack_chunk_t
)))
4393 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4395 unsigned int inittag
;
4397 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4398 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4403 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4404 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4406 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4407 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4408 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4409 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4410 SCTP_ERROR(ECONNREFUSED
));
4411 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4412 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4414 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4415 SCTP_ERROR(ECONNABORTED
));
4416 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4417 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4418 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4421 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
4426 if (sctp_test_T_bit(abort
))
4427 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4429 abort
->skb
->sk
= ep
->base
.sk
;
4431 sctp_packet_append_chunk(packet
, abort
);
4433 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4434 SCTP_PACKET(packet
));
4436 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4439 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4442 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4443 return SCTP_DISPOSITION_ABORT
;
4446 sctp_chunk_free(abort
);
4448 return SCTP_DISPOSITION_NOMEM
;
4452 * Handle a protocol violation when the chunk length is invalid.
4453 * "Invalid" length is identified as smaller than the minimal length a
4454 * given chunk can be. For example, a SACK chunk has invalid length
4455 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4457 * We inform the other end by sending an ABORT with a Protocol Violation
4460 * Section: Not specified
4461 * Verification Tag: Nothing to do
4463 * (endpoint, asoc, chunk)
4466 * (reply_msg, msg_up, counters)
4468 * Generate an ABORT chunk and terminate the association.
4470 static sctp_disposition_t
sctp_sf_violation_chunklen(
4472 const struct sctp_endpoint
*ep
,
4473 const struct sctp_association
*asoc
,
4474 const sctp_subtype_t type
,
4476 sctp_cmd_seq_t
*commands
)
4478 static const char err_str
[] = "The following chunk had invalid length:";
4480 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4485 * Handle a protocol violation when the parameter length is invalid.
4486 * If the length is smaller than the minimum length of a given parameter,
4487 * or accumulated length in multi parameters exceeds the end of the chunk,
4488 * the length is considered as invalid.
4490 static sctp_disposition_t
sctp_sf_violation_paramlen(
4492 const struct sctp_endpoint
*ep
,
4493 const struct sctp_association
*asoc
,
4494 const sctp_subtype_t type
,
4495 void *arg
, void *ext
,
4496 sctp_cmd_seq_t
*commands
)
4498 struct sctp_chunk
*chunk
= arg
;
4499 struct sctp_paramhdr
*param
= ext
;
4500 struct sctp_chunk
*abort
= NULL
;
4502 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4505 /* Make the abort chunk. */
4506 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4510 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4511 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4513 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4514 SCTP_ERROR(ECONNABORTED
));
4515 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4516 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4517 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4518 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4521 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4522 return SCTP_DISPOSITION_ABORT
;
4524 return SCTP_DISPOSITION_NOMEM
;
4527 /* Handle a protocol violation when the peer trying to advance the
4528 * cumulative tsn ack to a point beyond the max tsn currently sent.
4530 * We inform the other end by sending an ABORT with a Protocol Violation
4533 static sctp_disposition_t
sctp_sf_violation_ctsn(
4535 const struct sctp_endpoint
*ep
,
4536 const struct sctp_association
*asoc
,
4537 const sctp_subtype_t type
,
4539 sctp_cmd_seq_t
*commands
)
4541 static const char err_str
[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4543 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4547 /* Handle protocol violation of an invalid chunk bundling. For example,
4548 * when we have an association and we receive bundled INIT-ACK, or
4549 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4550 * statement from the specs. Additionally, there might be an attacker
4551 * on the path and we may not want to continue this communication.
4553 static sctp_disposition_t
sctp_sf_violation_chunk(
4555 const struct sctp_endpoint
*ep
,
4556 const struct sctp_association
*asoc
,
4557 const sctp_subtype_t type
,
4559 sctp_cmd_seq_t
*commands
)
4561 static const char err_str
[] = "The following chunk violates protocol:";
4564 return sctp_sf_violation(net
, ep
, asoc
, type
, arg
, commands
);
4566 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4569 /***************************************************************************
4570 * These are the state functions for handling primitive (Section 10) events.
4571 ***************************************************************************/
4573 * sctp_sf_do_prm_asoc
4575 * Section: 10.1 ULP-to-SCTP
4578 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4579 * outbound stream count)
4580 * -> association id [,destination transport addr list] [,outbound stream
4583 * This primitive allows the upper layer to initiate an association to a
4584 * specific peer endpoint.
4586 * The peer endpoint shall be specified by one of the transport addresses
4587 * which defines the endpoint (see Section 1.4). If the local SCTP
4588 * instance has not been initialized, the ASSOCIATE is considered an
4590 * [This is not relevant for the kernel implementation since we do all
4591 * initialization at boot time. It we hadn't initialized we wouldn't
4592 * get anywhere near this code.]
4594 * An association id, which is a local handle to the SCTP association,
4595 * will be returned on successful establishment of the association. If
4596 * SCTP is not able to open an SCTP association with the peer endpoint,
4597 * an error is returned.
4598 * [In the kernel implementation, the struct sctp_association needs to
4599 * be created BEFORE causing this primitive to run.]
4601 * Other association parameters may be returned, including the
4602 * complete destination transport addresses of the peer as well as the
4603 * outbound stream count of the local endpoint. One of the transport
4604 * address from the returned destination addresses will be selected by
4605 * the local endpoint as default primary path for sending SCTP packets
4606 * to this peer. The returned "destination transport addr list" can
4607 * be used by the ULP to change the default primary path or to force
4608 * sending a packet to a specific transport address. [All of this
4609 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4612 * Mandatory attributes:
4614 * o local SCTP instance name - obtained from the INITIALIZE operation.
4615 * [This is the argument asoc.]
4616 * o destination transport addr - specified as one of the transport
4617 * addresses of the peer endpoint with which the association is to be
4619 * [This is asoc->peer.active_path.]
4620 * o outbound stream count - the number of outbound streams the ULP
4621 * would like to open towards this peer endpoint.
4622 * [BUG: This is not currently implemented.]
4623 * Optional attributes:
4627 * The return value is a disposition.
4629 sctp_disposition_t
sctp_sf_do_prm_asoc(struct net
*net
,
4630 const struct sctp_endpoint
*ep
,
4631 const struct sctp_association
*asoc
,
4632 const sctp_subtype_t type
,
4634 sctp_cmd_seq_t
*commands
)
4636 struct sctp_chunk
*repl
;
4637 struct sctp_association
*my_asoc
;
4639 /* The comment below says that we enter COOKIE-WAIT AFTER
4640 * sending the INIT, but that doesn't actually work in our
4643 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4644 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4646 /* RFC 2960 5.1 Normal Establishment of an Association
4648 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4649 * must provide its Verification Tag (Tag_A) in the Initiate
4650 * Tag field. Tag_A SHOULD be a random number in the range of
4651 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4654 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4658 /* Choose transport for INIT. */
4659 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4662 /* Cast away the const modifier, as we want to just
4663 * rerun it through as a sideffect.
4665 my_asoc
= (struct sctp_association
*)asoc
;
4666 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4668 /* After sending the INIT, "A" starts the T1-init timer and
4669 * enters the COOKIE-WAIT state.
4671 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4672 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4673 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4674 return SCTP_DISPOSITION_CONSUME
;
4677 return SCTP_DISPOSITION_NOMEM
;
4681 * Process the SEND primitive.
4683 * Section: 10.1 ULP-to-SCTP
4686 * Format: SEND(association id, buffer address, byte count [,context]
4687 * [,stream id] [,life time] [,destination transport address]
4688 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4691 * This is the main method to send user data via SCTP.
4693 * Mandatory attributes:
4695 * o association id - local handle to the SCTP association
4697 * o buffer address - the location where the user message to be
4698 * transmitted is stored;
4700 * o byte count - The size of the user data in number of bytes;
4702 * Optional attributes:
4704 * o context - an optional 32 bit integer that will be carried in the
4705 * sending failure notification to the ULP if the transportation of
4706 * this User Message fails.
4708 * o stream id - to indicate which stream to send the data on. If not
4709 * specified, stream 0 will be used.
4711 * o life time - specifies the life time of the user data. The user data
4712 * will not be sent by SCTP after the life time expires. This
4713 * parameter can be used to avoid efforts to transmit stale
4714 * user messages. SCTP notifies the ULP if the data cannot be
4715 * initiated to transport (i.e. sent to the destination via SCTP's
4716 * send primitive) within the life time variable. However, the
4717 * user data will be transmitted if SCTP has attempted to transmit a
4718 * chunk before the life time expired.
4720 * o destination transport address - specified as one of the destination
4721 * transport addresses of the peer endpoint to which this packet
4722 * should be sent. Whenever possible, SCTP should use this destination
4723 * transport address for sending the packets, instead of the current
4726 * o unorder flag - this flag, if present, indicates that the user
4727 * would like the data delivered in an unordered fashion to the peer
4728 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4731 * o no-bundle flag - instructs SCTP not to bundle this user data with
4732 * other outbound DATA chunks. SCTP MAY still bundle even when
4733 * this flag is present, when faced with network congestion.
4735 * o payload protocol-id - A 32 bit unsigned integer that is to be
4736 * passed to the peer indicating the type of payload protocol data
4737 * being transmitted. This value is passed as opaque data by SCTP.
4739 * The return value is the disposition.
4741 sctp_disposition_t
sctp_sf_do_prm_send(struct net
*net
,
4742 const struct sctp_endpoint
*ep
,
4743 const struct sctp_association
*asoc
,
4744 const sctp_subtype_t type
,
4746 sctp_cmd_seq_t
*commands
)
4748 struct sctp_datamsg
*msg
= arg
;
4750 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4751 return SCTP_DISPOSITION_CONSUME
;
4755 * Process the SHUTDOWN primitive.
4760 * Format: SHUTDOWN(association id)
4763 * Gracefully closes an association. Any locally queued user data
4764 * will be delivered to the peer. The association will be terminated only
4765 * after the peer acknowledges all the SCTP packets sent. A success code
4766 * will be returned on successful termination of the association. If
4767 * attempting to terminate the association results in a failure, an error
4768 * code shall be returned.
4770 * Mandatory attributes:
4772 * o association id - local handle to the SCTP association
4774 * Optional attributes:
4778 * The return value is the disposition.
4780 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4782 const struct sctp_endpoint
*ep
,
4783 const struct sctp_association
*asoc
,
4784 const sctp_subtype_t type
,
4786 sctp_cmd_seq_t
*commands
)
4790 /* From 9.2 Shutdown of an Association
4791 * Upon receipt of the SHUTDOWN primitive from its upper
4792 * layer, the endpoint enters SHUTDOWN-PENDING state and
4793 * remains there until all outstanding data has been
4794 * acknowledged by its peer. The endpoint accepts no new data
4795 * from its upper layer, but retransmits data to the far end
4796 * if necessary to fill gaps.
4798 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4799 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4801 disposition
= SCTP_DISPOSITION_CONSUME
;
4802 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4803 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
4810 * Process the ABORT primitive.
4815 * Format: Abort(association id [, cause code])
4818 * Ungracefully closes an association. Any locally queued user data
4819 * will be discarded and an ABORT chunk is sent to the peer. A success code
4820 * will be returned on successful abortion of the association. If
4821 * attempting to abort the association results in a failure, an error
4822 * code shall be returned.
4824 * Mandatory attributes:
4826 * o association id - local handle to the SCTP association
4828 * Optional attributes:
4830 * o cause code - reason of the abort to be passed to the peer
4834 * The return value is the disposition.
4836 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4838 const struct sctp_endpoint
*ep
,
4839 const struct sctp_association
*asoc
,
4840 const sctp_subtype_t type
,
4842 sctp_cmd_seq_t
*commands
)
4844 /* From 9.1 Abort of an Association
4845 * Upon receipt of the ABORT primitive from its upper
4846 * layer, the endpoint enters CLOSED state and
4847 * discard all outstanding data has been
4848 * acknowledged by its peer. The endpoint accepts no new data
4849 * from its upper layer, but retransmits data to the far end
4850 * if necessary to fill gaps.
4852 struct sctp_chunk
*abort
= arg
;
4855 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4857 /* Even if we can't send the ABORT due to low memory delete the
4858 * TCB. This is a departure from our typical NOMEM handling.
4861 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4862 SCTP_ERROR(ECONNABORTED
));
4863 /* Delete the established association. */
4864 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4865 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4867 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4868 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4870 return SCTP_DISPOSITION_ABORT
;
4873 /* We tried an illegal operation on an association which is closed. */
4874 sctp_disposition_t
sctp_sf_error_closed(struct net
*net
,
4875 const struct sctp_endpoint
*ep
,
4876 const struct sctp_association
*asoc
,
4877 const sctp_subtype_t type
,
4879 sctp_cmd_seq_t
*commands
)
4881 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4882 return SCTP_DISPOSITION_CONSUME
;
4885 /* We tried an illegal operation on an association which is shutting
4888 sctp_disposition_t
sctp_sf_error_shutdown(struct net
*net
,
4889 const struct sctp_endpoint
*ep
,
4890 const struct sctp_association
*asoc
,
4891 const sctp_subtype_t type
,
4893 sctp_cmd_seq_t
*commands
)
4895 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4896 SCTP_ERROR(-ESHUTDOWN
));
4897 return SCTP_DISPOSITION_CONSUME
;
4901 * sctp_cookie_wait_prm_shutdown
4903 * Section: 4 Note: 2
4908 * The RFC does not explicitly address this issue, but is the route through the
4909 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4914 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4916 const struct sctp_endpoint
*ep
,
4917 const struct sctp_association
*asoc
,
4918 const sctp_subtype_t type
,
4920 sctp_cmd_seq_t
*commands
)
4922 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4923 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4925 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4926 SCTP_STATE(SCTP_STATE_CLOSED
));
4928 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
4930 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4932 return SCTP_DISPOSITION_DELETE_TCB
;
4936 * sctp_cookie_echoed_prm_shutdown
4938 * Section: 4 Note: 2
4943 * The RFC does not explcitly address this issue, but is the route through the
4944 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4949 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4951 const struct sctp_endpoint
*ep
,
4952 const struct sctp_association
*asoc
,
4953 const sctp_subtype_t type
,
4954 void *arg
, sctp_cmd_seq_t
*commands
)
4956 /* There is a single T1 timer, so we should be able to use
4957 * common function with the COOKIE-WAIT state.
4959 return sctp_sf_cookie_wait_prm_shutdown(net
, ep
, asoc
, type
, arg
, commands
);
4963 * sctp_sf_cookie_wait_prm_abort
4965 * Section: 4 Note: 2
4970 * The RFC does not explicitly address this issue, but is the route through the
4971 * state table when someone issues an abort while in COOKIE_WAIT state.
4976 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4978 const struct sctp_endpoint
*ep
,
4979 const struct sctp_association
*asoc
,
4980 const sctp_subtype_t type
,
4982 sctp_cmd_seq_t
*commands
)
4984 struct sctp_chunk
*abort
= arg
;
4986 /* Stop T1-init timer */
4987 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4988 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4991 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4993 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4994 SCTP_STATE(SCTP_STATE_CLOSED
));
4996 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4998 /* Even if we can't send the ABORT due to low memory delete the
4999 * TCB. This is a departure from our typical NOMEM handling.
5002 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5003 SCTP_ERROR(ECONNREFUSED
));
5004 /* Delete the established association. */
5005 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5006 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
5008 return SCTP_DISPOSITION_ABORT
;
5012 * sctp_sf_cookie_echoed_prm_abort
5014 * Section: 4 Note: 3
5019 * The RFC does not explcitly address this issue, but is the route through the
5020 * state table when someone issues an abort while in COOKIE_ECHOED state.
5025 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
5027 const struct sctp_endpoint
*ep
,
5028 const struct sctp_association
*asoc
,
5029 const sctp_subtype_t type
,
5031 sctp_cmd_seq_t
*commands
)
5033 /* There is a single T1 timer, so we should be able to use
5034 * common function with the COOKIE-WAIT state.
5036 return sctp_sf_cookie_wait_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5040 * sctp_sf_shutdown_pending_prm_abort
5045 * The RFC does not explicitly address this issue, but is the route through the
5046 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5051 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
5053 const struct sctp_endpoint
*ep
,
5054 const struct sctp_association
*asoc
,
5055 const sctp_subtype_t type
,
5057 sctp_cmd_seq_t
*commands
)
5059 /* Stop the T5-shutdown guard timer. */
5060 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5061 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5063 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5067 * sctp_sf_shutdown_sent_prm_abort
5072 * The RFC does not explicitly address this issue, but is the route through the
5073 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5078 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
5080 const struct sctp_endpoint
*ep
,
5081 const struct sctp_association
*asoc
,
5082 const sctp_subtype_t type
,
5084 sctp_cmd_seq_t
*commands
)
5086 /* Stop the T2-shutdown timer. */
5087 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5088 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5090 /* Stop the T5-shutdown guard timer. */
5091 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5092 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5094 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5098 * sctp_sf_cookie_echoed_prm_abort
5103 * The RFC does not explcitly address this issue, but is the route through the
5104 * state table when someone issues an abort while in COOKIE_ECHOED state.
5109 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
5111 const struct sctp_endpoint
*ep
,
5112 const struct sctp_association
*asoc
,
5113 const sctp_subtype_t type
,
5115 sctp_cmd_seq_t
*commands
)
5117 /* The same T2 timer, so we should be able to use
5118 * common function with the SHUTDOWN-SENT state.
5120 return sctp_sf_shutdown_sent_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5124 * Process the REQUESTHEARTBEAT primitive
5127 * J) Request Heartbeat
5129 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5133 * Instructs the local endpoint to perform a HeartBeat on the specified
5134 * destination transport address of the given association. The returned
5135 * result should indicate whether the transmission of the HEARTBEAT
5136 * chunk to the destination address is successful.
5138 * Mandatory attributes:
5140 * o association id - local handle to the SCTP association
5142 * o destination transport address - the transport address of the
5143 * association on which a heartbeat should be issued.
5145 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5147 const struct sctp_endpoint
*ep
,
5148 const struct sctp_association
*asoc
,
5149 const sctp_subtype_t type
,
5151 sctp_cmd_seq_t
*commands
)
5153 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5154 (struct sctp_transport
*)arg
, commands
))
5155 return SCTP_DISPOSITION_NOMEM
;
5158 * RFC 2960 (bis), section 8.3
5160 * D) Request an on-demand HEARTBEAT on a specific destination
5161 * transport address of a given association.
5163 * The endpoint should increment the respective error counter of
5164 * the destination transport address each time a HEARTBEAT is sent
5165 * to that address and not acknowledged within one RTO.
5168 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5169 SCTP_TRANSPORT(arg
));
5170 return SCTP_DISPOSITION_CONSUME
;
5174 * ADDIP Section 4.1 ASCONF Chunk Procedures
5175 * When an endpoint has an ASCONF signaled change to be sent to the
5176 * remote endpoint it should do A1 to A9
5178 sctp_disposition_t
sctp_sf_do_prm_asconf(struct net
*net
,
5179 const struct sctp_endpoint
*ep
,
5180 const struct sctp_association
*asoc
,
5181 const sctp_subtype_t type
,
5183 sctp_cmd_seq_t
*commands
)
5185 struct sctp_chunk
*chunk
= arg
;
5187 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5188 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5189 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5190 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5191 return SCTP_DISPOSITION_CONSUME
;
5194 /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5195 sctp_disposition_t
sctp_sf_do_prm_reconf(struct net
*net
,
5196 const struct sctp_endpoint
*ep
,
5197 const struct sctp_association
*asoc
,
5198 const sctp_subtype_t type
,
5199 void *arg
, sctp_cmd_seq_t
*commands
)
5201 struct sctp_chunk
*chunk
= arg
;
5203 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5204 return SCTP_DISPOSITION_CONSUME
;
5208 * Ignore the primitive event
5210 * The return value is the disposition of the primitive.
5212 sctp_disposition_t
sctp_sf_ignore_primitive(
5214 const struct sctp_endpoint
*ep
,
5215 const struct sctp_association
*asoc
,
5216 const sctp_subtype_t type
,
5218 sctp_cmd_seq_t
*commands
)
5220 pr_debug("%s: primitive type:%d is ignored\n", __func__
,
5223 return SCTP_DISPOSITION_DISCARD
;
5226 /***************************************************************************
5227 * These are the state functions for the OTHER events.
5228 ***************************************************************************/
5231 * When the SCTP stack has no more user data to send or retransmit, this
5232 * notification is given to the user. Also, at the time when a user app
5233 * subscribes to this event, if there is no data to be sent or
5234 * retransmit, the stack will immediately send up this notification.
5236 sctp_disposition_t
sctp_sf_do_no_pending_tsn(
5238 const struct sctp_endpoint
*ep
,
5239 const struct sctp_association
*asoc
,
5240 const sctp_subtype_t type
,
5242 sctp_cmd_seq_t
*commands
)
5244 struct sctp_ulpevent
*event
;
5246 event
= sctp_ulpevent_make_sender_dry_event(asoc
, GFP_ATOMIC
);
5248 return SCTP_DISPOSITION_NOMEM
;
5250 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(event
));
5252 return SCTP_DISPOSITION_CONSUME
;
5256 * Start the shutdown negotiation.
5259 * Once all its outstanding data has been acknowledged, the endpoint
5260 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5261 * TSN Ack field the last sequential TSN it has received from the peer.
5262 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5263 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5264 * with the updated last sequential TSN received from its peer.
5266 * The return value is the disposition.
5268 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
5270 const struct sctp_endpoint
*ep
,
5271 const struct sctp_association
*asoc
,
5272 const sctp_subtype_t type
,
5274 sctp_cmd_seq_t
*commands
)
5276 struct sctp_chunk
*reply
;
5278 /* Once all its outstanding data has been acknowledged, the
5279 * endpoint shall send a SHUTDOWN chunk to its peer including
5280 * in the Cumulative TSN Ack field the last sequential TSN it
5281 * has received from the peer.
5283 reply
= sctp_make_shutdown(asoc
, NULL
);
5287 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5288 * T2-shutdown timer.
5290 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5292 /* It shall then start the T2-shutdown timer */
5293 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5294 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5296 /* RFC 4960 Section 9.2
5297 * The sender of the SHUTDOWN MAY also start an overall guard timer
5298 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5300 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5301 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5303 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5304 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5305 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5307 /* and enter the SHUTDOWN-SENT state. */
5308 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5309 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5311 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5313 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5316 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5318 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5320 return SCTP_DISPOSITION_CONSUME
;
5323 return SCTP_DISPOSITION_NOMEM
;
5327 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5331 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5332 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5333 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5334 * endpoint must re-send the SHUTDOWN ACK.
5336 * The return value is the disposition.
5338 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5340 const struct sctp_endpoint
*ep
,
5341 const struct sctp_association
*asoc
,
5342 const sctp_subtype_t type
,
5344 sctp_cmd_seq_t
*commands
)
5346 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5347 struct sctp_chunk
*reply
;
5349 /* There are 2 ways of getting here:
5350 * 1) called in response to a SHUTDOWN chunk
5351 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5353 * For the case (2), the arg parameter is set to NULL. We need
5354 * to check that we have a chunk before accessing it's fields.
5357 if (!sctp_vtag_verify(chunk
, asoc
))
5358 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
5360 /* Make sure that the SHUTDOWN chunk has a valid length. */
5361 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5362 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
5366 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5367 * shall send a SHUTDOWN ACK ...
5369 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5373 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5374 * the T2-shutdown timer.
5376 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5378 /* and start/restart a T2-shutdown timer of its own, */
5379 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5380 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5382 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5383 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5384 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5386 /* Enter the SHUTDOWN-ACK-SENT state. */
5387 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5388 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5390 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5392 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5395 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5397 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5399 return SCTP_DISPOSITION_CONSUME
;
5402 return SCTP_DISPOSITION_NOMEM
;
5406 * Ignore the event defined as other
5408 * The return value is the disposition of the event.
5410 sctp_disposition_t
sctp_sf_ignore_other(struct net
*net
,
5411 const struct sctp_endpoint
*ep
,
5412 const struct sctp_association
*asoc
,
5413 const sctp_subtype_t type
,
5415 sctp_cmd_seq_t
*commands
)
5417 pr_debug("%s: the event other type:%d is ignored\n",
5418 __func__
, type
.other
);
5420 return SCTP_DISPOSITION_DISCARD
;
5423 /************************************************************
5424 * These are the state functions for handling timeout events.
5425 ************************************************************/
5430 * Section: 6.3.3 Handle T3-rtx Expiration
5432 * Whenever the retransmission timer T3-rtx expires for a destination
5433 * address, do the following:
5436 * The return value is the disposition of the chunk.
5438 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(struct net
*net
,
5439 const struct sctp_endpoint
*ep
,
5440 const struct sctp_association
*asoc
,
5441 const sctp_subtype_t type
,
5443 sctp_cmd_seq_t
*commands
)
5445 struct sctp_transport
*transport
= arg
;
5447 SCTP_INC_STATS(net
, SCTP_MIB_T3_RTX_EXPIREDS
);
5449 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5450 if (asoc
->peer
.zero_window_announced
&&
5451 asoc
->state
== SCTP_STATE_SHUTDOWN_PENDING
) {
5453 * We are here likely because the receiver had its rwnd
5454 * closed for a while and we have not been able to
5455 * transmit the locally queued data within the maximum
5456 * retransmission attempts limit. Start the T5
5457 * shutdown guard timer to give the receiver one last
5458 * chance and some additional time to recover before
5461 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START_ONCE
,
5462 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5464 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5465 SCTP_ERROR(ETIMEDOUT
));
5466 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5467 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5468 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5469 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5470 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5471 return SCTP_DISPOSITION_DELETE_TCB
;
5475 /* E1) For the destination address for which the timer
5476 * expires, adjust its ssthresh with rules defined in Section
5477 * 7.2.3 and set the cwnd <- MTU.
5480 /* E2) For the destination address for which the timer
5481 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5482 * maximum value discussed in rule C7 above (RTO.max) may be
5483 * used to provide an upper bound to this doubling operation.
5486 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5487 * outstanding DATA chunks for the address for which the
5488 * T3-rtx has expired will fit into a single packet, subject
5489 * to the MTU constraint for the path corresponding to the
5490 * destination transport address to which the retransmission
5491 * is being sent (this may be different from the address for
5492 * which the timer expires [see Section 6.4]). Call this
5493 * value K. Bundle and retransmit those K DATA chunks in a
5494 * single packet to the destination endpoint.
5496 * Note: Any DATA chunks that were sent to the address for
5497 * which the T3-rtx timer expired but did not fit in one MTU
5498 * (rule E3 above), should be marked for retransmission and
5499 * sent as soon as cwnd allows (normally when a SACK arrives).
5502 /* Do some failure management (Section 8.2). */
5503 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5505 /* NB: Rules E4 and F1 are implicit in R1. */
5506 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5508 return SCTP_DISPOSITION_CONSUME
;
5512 * Generate delayed SACK on timeout
5514 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5516 * The guidelines on delayed acknowledgement algorithm specified in
5517 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5518 * acknowledgement SHOULD be generated for at least every second packet
5519 * (not every second DATA chunk) received, and SHOULD be generated
5520 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5521 * some situations it may be beneficial for an SCTP transmitter to be
5522 * more conservative than the algorithms detailed in this document
5523 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5524 * the following algorithms allow.
5526 sctp_disposition_t
sctp_sf_do_6_2_sack(struct net
*net
,
5527 const struct sctp_endpoint
*ep
,
5528 const struct sctp_association
*asoc
,
5529 const sctp_subtype_t type
,
5531 sctp_cmd_seq_t
*commands
)
5533 SCTP_INC_STATS(net
, SCTP_MIB_DELAY_SACK_EXPIREDS
);
5534 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5535 return SCTP_DISPOSITION_CONSUME
;
5539 * sctp_sf_t1_init_timer_expire
5541 * Section: 4 Note: 2
5546 * RFC 2960 Section 4 Notes
5547 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5548 * and re-start the T1-init timer without changing state. This MUST
5549 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5550 * endpoint MUST abort the initialization process and report the
5551 * error to SCTP user.
5557 sctp_disposition_t
sctp_sf_t1_init_timer_expire(struct net
*net
,
5558 const struct sctp_endpoint
*ep
,
5559 const struct sctp_association
*asoc
,
5560 const sctp_subtype_t type
,
5562 sctp_cmd_seq_t
*commands
)
5564 struct sctp_chunk
*repl
= NULL
;
5565 struct sctp_bind_addr
*bp
;
5566 int attempts
= asoc
->init_err_counter
+ 1;
5568 pr_debug("%s: timer T1 expired (INIT)\n", __func__
);
5570 SCTP_INC_STATS(net
, SCTP_MIB_T1_INIT_EXPIREDS
);
5572 if (attempts
<= asoc
->max_init_attempts
) {
5573 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5574 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5576 return SCTP_DISPOSITION_NOMEM
;
5578 /* Choose transport for INIT. */
5579 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5582 /* Issue a sideeffect to do the needed accounting. */
5583 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5584 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5586 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5588 pr_debug("%s: giving up on INIT, attempts:%d "
5589 "max_init_attempts:%d\n", __func__
, attempts
,
5590 asoc
->max_init_attempts
);
5592 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5593 SCTP_ERROR(ETIMEDOUT
));
5594 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5595 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5596 return SCTP_DISPOSITION_DELETE_TCB
;
5599 return SCTP_DISPOSITION_CONSUME
;
5603 * sctp_sf_t1_cookie_timer_expire
5605 * Section: 4 Note: 2
5610 * RFC 2960 Section 4 Notes
5611 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5612 * COOKIE ECHO and re-start the T1-cookie timer without changing
5613 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5614 * After that, the endpoint MUST abort the initialization process and
5615 * report the error to SCTP user.
5621 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(struct net
*net
,
5622 const struct sctp_endpoint
*ep
,
5623 const struct sctp_association
*asoc
,
5624 const sctp_subtype_t type
,
5626 sctp_cmd_seq_t
*commands
)
5628 struct sctp_chunk
*repl
= NULL
;
5629 int attempts
= asoc
->init_err_counter
+ 1;
5631 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__
);
5633 SCTP_INC_STATS(net
, SCTP_MIB_T1_COOKIE_EXPIREDS
);
5635 if (attempts
<= asoc
->max_init_attempts
) {
5636 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5638 return SCTP_DISPOSITION_NOMEM
;
5640 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5642 /* Issue a sideeffect to do the needed accounting. */
5643 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5644 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5646 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5648 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5649 SCTP_ERROR(ETIMEDOUT
));
5650 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5651 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5652 return SCTP_DISPOSITION_DELETE_TCB
;
5655 return SCTP_DISPOSITION_CONSUME
;
5658 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5659 * with the updated last sequential TSN received from its peer.
5661 * An endpoint should limit the number of retransmissions of the
5662 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5663 * If this threshold is exceeded the endpoint should destroy the TCB and
5664 * MUST report the peer endpoint unreachable to the upper layer (and
5665 * thus the association enters the CLOSED state). The reception of any
5666 * packet from its peer (i.e. as the peer sends all of its queued DATA
5667 * chunks) should clear the endpoint's retransmission count and restart
5668 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5669 * all of its queued DATA chunks that have not yet been sent.
5671 sctp_disposition_t
sctp_sf_t2_timer_expire(struct net
*net
,
5672 const struct sctp_endpoint
*ep
,
5673 const struct sctp_association
*asoc
,
5674 const sctp_subtype_t type
,
5676 sctp_cmd_seq_t
*commands
)
5678 struct sctp_chunk
*reply
= NULL
;
5680 pr_debug("%s: timer T2 expired\n", __func__
);
5682 SCTP_INC_STATS(net
, SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5684 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5686 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5687 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5688 SCTP_ERROR(ETIMEDOUT
));
5689 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5690 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5691 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5692 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5693 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5694 return SCTP_DISPOSITION_DELETE_TCB
;
5697 switch (asoc
->state
) {
5698 case SCTP_STATE_SHUTDOWN_SENT
:
5699 reply
= sctp_make_shutdown(asoc
, NULL
);
5702 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5703 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5714 /* Do some failure management (Section 8.2).
5715 * If we remove the transport an SHUTDOWN was last sent to, don't
5716 * do failure management.
5718 if (asoc
->shutdown_last_sent_to
)
5719 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5720 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5722 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5723 * the T2-shutdown timer.
5725 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5727 /* Restart the T2-shutdown timer. */
5728 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5729 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5730 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5731 return SCTP_DISPOSITION_CONSUME
;
5734 return SCTP_DISPOSITION_NOMEM
;
5738 * ADDIP Section 4.1 ASCONF CHunk Procedures
5739 * If the T4 RTO timer expires the endpoint should do B1 to B5
5741 sctp_disposition_t
sctp_sf_t4_timer_expire(
5743 const struct sctp_endpoint
*ep
,
5744 const struct sctp_association
*asoc
,
5745 const sctp_subtype_t type
,
5747 sctp_cmd_seq_t
*commands
)
5749 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5750 struct sctp_transport
*transport
= chunk
->transport
;
5752 SCTP_INC_STATS(net
, SCTP_MIB_T4_RTO_EXPIREDS
);
5754 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5755 * detection on the appropriate destination address as defined in
5756 * RFC2960 [5] section 8.1 and 8.2.
5759 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5760 SCTP_TRANSPORT(transport
));
5762 /* Reconfig T4 timer and transport. */
5763 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5765 /* ADDIP 4.1 B2) Increment the association error counters and perform
5766 * endpoint failure detection on the association as defined in
5767 * RFC2960 [5] section 8.1 and 8.2.
5768 * association error counter is incremented in SCTP_CMD_STRIKE.
5770 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5771 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5772 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5773 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5774 SCTP_ERROR(ETIMEDOUT
));
5775 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5776 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5777 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5778 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5779 return SCTP_DISPOSITION_ABORT
;
5782 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5783 * the ASCONF chunk was sent by doubling the RTO timer value.
5784 * This is done in SCTP_CMD_STRIKE.
5787 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5788 * choose an alternate destination address (please refer to RFC2960
5789 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5790 * chunk, it MUST be the same (including its serial number) as the last
5793 sctp_chunk_hold(asoc
->addip_last_asconf
);
5794 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5795 SCTP_CHUNK(asoc
->addip_last_asconf
));
5797 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5798 * destination is selected, then the RTO used will be that of the new
5799 * destination address.
5801 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5802 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5804 return SCTP_DISPOSITION_CONSUME
;
5807 /* sctpimpguide-05 Section 2.12.2
5808 * The sender of the SHUTDOWN MAY also start an overall guard timer
5809 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5810 * At the expiration of this timer the sender SHOULD abort the association
5811 * by sending an ABORT chunk.
5813 sctp_disposition_t
sctp_sf_t5_timer_expire(struct net
*net
,
5814 const struct sctp_endpoint
*ep
,
5815 const struct sctp_association
*asoc
,
5816 const sctp_subtype_t type
,
5818 sctp_cmd_seq_t
*commands
)
5820 struct sctp_chunk
*reply
= NULL
;
5822 pr_debug("%s: timer T5 expired\n", __func__
);
5824 SCTP_INC_STATS(net
, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5826 reply
= sctp_make_abort(asoc
, NULL
, 0);
5830 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5831 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5832 SCTP_ERROR(ETIMEDOUT
));
5833 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5834 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5836 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5837 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5839 return SCTP_DISPOSITION_DELETE_TCB
;
5841 return SCTP_DISPOSITION_NOMEM
;
5844 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5845 * the association is automatically closed by starting the shutdown process.
5846 * The work that needs to be done is same as when SHUTDOWN is initiated by
5847 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5849 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5851 const struct sctp_endpoint
*ep
,
5852 const struct sctp_association
*asoc
,
5853 const sctp_subtype_t type
,
5855 sctp_cmd_seq_t
*commands
)
5859 SCTP_INC_STATS(net
, SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5861 /* From 9.2 Shutdown of an Association
5862 * Upon receipt of the SHUTDOWN primitive from its upper
5863 * layer, the endpoint enters SHUTDOWN-PENDING state and
5864 * remains there until all outstanding data has been
5865 * acknowledged by its peer. The endpoint accepts no new data
5866 * from its upper layer, but retransmits data to the far end
5867 * if necessary to fill gaps.
5869 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5870 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5872 disposition
= SCTP_DISPOSITION_CONSUME
;
5873 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5874 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
5880 /*****************************************************************************
5881 * These are sa state functions which could apply to all types of events.
5882 ****************************************************************************/
5885 * This table entry is not implemented.
5888 * (endpoint, asoc, chunk)
5890 * The return value is the disposition of the chunk.
5892 sctp_disposition_t
sctp_sf_not_impl(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 return SCTP_DISPOSITION_NOT_IMPL
;
5903 * This table entry represents a bug.
5906 * (endpoint, asoc, chunk)
5908 * The return value is the disposition of the chunk.
5910 sctp_disposition_t
sctp_sf_bug(struct net
*net
,
5911 const struct sctp_endpoint
*ep
,
5912 const struct sctp_association
*asoc
,
5913 const sctp_subtype_t type
,
5915 sctp_cmd_seq_t
*commands
)
5917 return SCTP_DISPOSITION_BUG
;
5921 * This table entry represents the firing of a timer in the wrong state.
5922 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5923 * when the association is in the wrong state. This event should
5924 * be ignored, so as to prevent any rearming of the timer.
5927 * (endpoint, asoc, chunk)
5929 * The return value is the disposition of the chunk.
5931 sctp_disposition_t
sctp_sf_timer_ignore(struct net
*net
,
5932 const struct sctp_endpoint
*ep
,
5933 const struct sctp_association
*asoc
,
5934 const sctp_subtype_t type
,
5936 sctp_cmd_seq_t
*commands
)
5938 pr_debug("%s: timer %d ignored\n", __func__
, type
.chunk
);
5940 return SCTP_DISPOSITION_CONSUME
;
5943 /********************************************************************
5944 * 2nd Level Abstractions
5945 ********************************************************************/
5947 /* Pull the SACK chunk based on the SACK header. */
5948 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5950 struct sctp_sackhdr
*sack
;
5955 /* Protect ourselves from reading too far into
5956 * the skb from a bogus sender.
5958 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5960 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5961 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5962 len
= sizeof(struct sctp_sackhdr
);
5963 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5964 if (len
> chunk
->skb
->len
)
5967 skb_pull(chunk
->skb
, len
);
5972 /* Create an ABORT packet to be sent as a response, with the specified
5975 static struct sctp_packet
*sctp_abort_pkt_new(struct net
*net
,
5976 const struct sctp_endpoint
*ep
,
5977 const struct sctp_association
*asoc
,
5978 struct sctp_chunk
*chunk
,
5979 const void *payload
,
5982 struct sctp_packet
*packet
;
5983 struct sctp_chunk
*abort
;
5985 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
5989 * The T bit will be set if the asoc is NULL.
5991 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5993 sctp_ootb_pkt_free(packet
);
5997 /* Reflect vtag if T-Bit is set */
5998 if (sctp_test_T_bit(abort
))
5999 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
6001 /* Add specified error causes, i.e., payload, to the
6004 sctp_addto_chunk(abort
, paylen
, payload
);
6006 /* Set the skb to the belonging sock for accounting. */
6007 abort
->skb
->sk
= ep
->base
.sk
;
6009 sctp_packet_append_chunk(packet
, abort
);
6016 /* Allocate a packet for responding in the OOTB conditions. */
6017 static struct sctp_packet
*sctp_ootb_pkt_new(struct net
*net
,
6018 const struct sctp_association
*asoc
,
6019 const struct sctp_chunk
*chunk
)
6021 struct sctp_packet
*packet
;
6022 struct sctp_transport
*transport
;
6027 /* Get the source and destination port from the inbound packet. */
6028 sport
= ntohs(chunk
->sctp_hdr
->dest
);
6029 dport
= ntohs(chunk
->sctp_hdr
->source
);
6031 /* The V-tag is going to be the same as the inbound packet if no
6032 * association exists, otherwise, use the peer's vtag.
6035 /* Special case the INIT-ACK as there is no peer's vtag
6038 switch (chunk
->chunk_hdr
->type
) {
6039 case SCTP_CID_INIT_ACK
:
6041 sctp_initack_chunk_t
*initack
;
6043 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
6044 vtag
= ntohl(initack
->init_hdr
.init_tag
);
6048 vtag
= asoc
->peer
.i
.init_tag
;
6052 /* Special case the INIT and stale COOKIE_ECHO as there is no
6055 switch (chunk
->chunk_hdr
->type
) {
6058 sctp_init_chunk_t
*init
;
6060 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
6061 vtag
= ntohl(init
->init_hdr
.init_tag
);
6065 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
6070 /* Make a transport for the bucket, Eliza... */
6071 transport
= sctp_transport_new(net
, sctp_source(chunk
), GFP_ATOMIC
);
6075 /* Cache a route for the transport with the chunk's destination as
6076 * the source address.
6078 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
6079 sctp_sk(net
->sctp
.ctl_sock
));
6081 packet
= &transport
->packet
;
6082 sctp_packet_init(packet
, transport
, sport
, dport
);
6083 sctp_packet_config(packet
, vtag
, 0);
6091 /* Free the packet allocated earlier for responding in the OOTB condition. */
6092 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
6094 sctp_transport_free(packet
->transport
);
6097 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6098 static void sctp_send_stale_cookie_err(struct net
*net
,
6099 const struct sctp_endpoint
*ep
,
6100 const struct sctp_association
*asoc
,
6101 const struct sctp_chunk
*chunk
,
6102 sctp_cmd_seq_t
*commands
,
6103 struct sctp_chunk
*err_chunk
)
6105 struct sctp_packet
*packet
;
6108 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
6110 struct sctp_signed_cookie
*cookie
;
6112 /* Override the OOTB vtag from the cookie. */
6113 cookie
= chunk
->subh
.cookie_hdr
;
6114 packet
->vtag
= cookie
->c
.peer_vtag
;
6116 /* Set the skb to the belonging sock for accounting. */
6117 err_chunk
->skb
->sk
= ep
->base
.sk
;
6118 sctp_packet_append_chunk(packet
, err_chunk
);
6119 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
6120 SCTP_PACKET(packet
));
6121 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
6123 sctp_chunk_free (err_chunk
);
6128 /* Process a data chunk */
6129 static int sctp_eat_data(const struct sctp_association
*asoc
,
6130 struct sctp_chunk
*chunk
,
6131 sctp_cmd_seq_t
*commands
)
6133 sctp_datahdr_t
*data_hdr
;
6134 struct sctp_chunk
*err
;
6136 sctp_verb_t deliver
;
6139 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
6140 struct sock
*sk
= asoc
->base
.sk
;
6141 struct net
*net
= sock_net(sk
);
6146 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
6147 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
6149 tsn
= ntohl(data_hdr
->tsn
);
6150 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
6152 /* ASSERT: Now skb->data is really the user data. */
6154 /* Process ECN based congestion.
6156 * Since the chunk structure is reused for all chunks within
6157 * a packet, we use ecn_ce_done to track if we've already
6158 * done CE processing for this packet.
6160 * We need to do ECN processing even if we plan to discard the
6164 if (asoc
->peer
.ecn_capable
&& !chunk
->ecn_ce_done
) {
6165 struct sctp_af
*af
= SCTP_INPUT_CB(chunk
->skb
)->af
;
6166 chunk
->ecn_ce_done
= 1;
6168 if (af
->is_ce(sctp_gso_headskb(chunk
->skb
))) {
6169 /* Do real work as sideffect. */
6170 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
6175 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
6177 /* The TSN is too high--silently discard the chunk and
6178 * count on it getting retransmitted later.
6181 chunk
->asoc
->stats
.outofseqtsns
++;
6182 return SCTP_IERROR_HIGH_TSN
;
6183 } else if (tmp
> 0) {
6184 /* This is a duplicate. Record it. */
6185 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
6186 return SCTP_IERROR_DUP_TSN
;
6189 /* This is a new TSN. */
6191 /* Discard if there is no room in the receive window.
6192 * Actually, allow a little bit of overflow (up to a MTU).
6194 datalen
= ntohs(chunk
->chunk_hdr
->length
);
6195 datalen
-= sizeof(sctp_data_chunk_t
);
6197 deliver
= SCTP_CMD_CHUNK_ULP
;
6199 /* Think about partial delivery. */
6200 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
6202 /* Even if we don't accept this chunk there is
6205 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
6208 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6209 * seems a bit troublesome in that frag_point varies based on
6210 * PMTU. In cases, such as loopback, this might be a rather
6213 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
6214 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
6216 /* If this is the next TSN, consider reneging to make
6217 * room. Note: Playing nice with a confused sender. A
6218 * malicious sender can still eat up all our buffer
6219 * space and in the future we may want to detect and
6220 * do more drastic reneging.
6222 if (sctp_tsnmap_has_gap(map
) &&
6223 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6224 pr_debug("%s: reneging for tsn:%u\n", __func__
, tsn
);
6225 deliver
= SCTP_CMD_RENEGE
;
6227 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6228 __func__
, tsn
, datalen
, asoc
->rwnd
);
6230 return SCTP_IERROR_IGNORE_TSN
;
6235 * Also try to renege to limit our memory usage in the event that
6236 * we are under memory pressure
6237 * If we can't renege, don't worry about it, the sk_rmem_schedule
6238 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6239 * memory usage too much
6241 if (*sk
->sk_prot_creator
->memory_pressure
) {
6242 if (sctp_tsnmap_has_gap(map
) &&
6243 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6244 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6246 deliver
= SCTP_CMD_RENEGE
;
6251 * Section 3.3.10.9 No User Data (9)
6255 * No User Data: This error cause is returned to the originator of a
6256 * DATA chunk if a received DATA chunk has no user data.
6258 if (unlikely(0 == datalen
)) {
6259 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6261 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6264 /* We are going to ABORT, so we might as well stop
6265 * processing the rest of the chunks in the packet.
6267 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
6268 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6269 SCTP_ERROR(ECONNABORTED
));
6270 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6271 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6272 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
6273 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
6274 return SCTP_IERROR_NO_DATA
;
6277 chunk
->data_accepted
= 1;
6279 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6280 * if we renege and the chunk arrives again.
6282 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
) {
6283 SCTP_INC_STATS(net
, SCTP_MIB_INUNORDERCHUNKS
);
6285 chunk
->asoc
->stats
.iuodchunks
++;
6287 SCTP_INC_STATS(net
, SCTP_MIB_INORDERCHUNKS
);
6289 chunk
->asoc
->stats
.iodchunks
++;
6293 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6295 * If an endpoint receive a DATA chunk with an invalid stream
6296 * identifier, it shall acknowledge the reception of the DATA chunk
6297 * following the normal procedure, immediately send an ERROR chunk
6298 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6299 * and discard the DATA chunk.
6301 sid
= ntohs(data_hdr
->stream
);
6302 if (sid
>= asoc
->c
.sinit_max_instreams
) {
6303 /* Mark tsn as received even though we drop it */
6304 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6306 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6308 sizeof(data_hdr
->stream
),
6311 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6313 return SCTP_IERROR_BAD_STREAM
;
6316 /* Check to see if the SSN is possible for this TSN.
6317 * The biggest gap we can record is 4K wide. Since SSNs wrap
6318 * at an unsigned short, there is no way that an SSN can
6319 * wrap and for a valid TSN. We can simply check if the current
6320 * SSN is smaller then the next expected one. If it is, it wrapped
6323 ssn
= ntohs(data_hdr
->ssn
);
6324 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(asoc
->stream
, in
, sid
)))
6325 return SCTP_IERROR_PROTO_VIOLATION
;
6327 /* Send the data up to the user. Note: Schedule the
6328 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6329 * chunk needs the updated rwnd.
6331 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6333 return SCTP_IERROR_NO_ERROR
;