1 /* SCTP kernel reference 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 file is part of the SCTP kernel reference Implementation
10 * This is part of the SCTP Linux Kernel Reference Implementation.
12 * These are the state functions for the state machine.
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
31 * Please send any bug reports or fixes you make to the
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
55 #include <linux/types.h>
56 #include <linux/kernel.h>
58 #include <linux/ipv6.h>
59 #include <linux/net.h>
60 #include <linux/inet.h>
62 #include <net/inet_ecn.h>
63 #include <linux/skbuff.h>
64 #include <net/sctp/sctp.h>
65 #include <net/sctp/sm.h>
66 #include <net/sctp/structs.h>
68 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
69 const struct sctp_association
*asoc
,
70 struct sctp_chunk
*chunk
,
73 static int sctp_eat_data(const struct sctp_association
*asoc
,
74 struct sctp_chunk
*chunk
,
75 sctp_cmd_seq_t
*commands
);
76 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
77 const struct sctp_chunk
*chunk
);
78 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
79 const struct sctp_association
*asoc
,
80 const struct sctp_chunk
*chunk
,
81 sctp_cmd_seq_t
*commands
,
82 struct sctp_chunk
*err_chunk
);
83 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
84 const struct sctp_association
*asoc
,
85 const sctp_subtype_t type
,
87 sctp_cmd_seq_t
*commands
);
88 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
89 const struct sctp_association
*asoc
,
90 const sctp_subtype_t type
,
92 sctp_cmd_seq_t
*commands
);
93 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
95 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
97 const struct sctp_association
*asoc
,
98 struct sctp_transport
*transport
);
100 static sctp_disposition_t
sctp_sf_violation_chunklen(
101 const struct sctp_endpoint
*ep
,
102 const struct sctp_association
*asoc
,
103 const sctp_subtype_t type
,
105 sctp_cmd_seq_t
*commands
);
107 /* Small helper function that checks if the chunk length
108 * is of the appropriate length. The 'required_length' argument
109 * is set to be the size of a specific chunk we are testing.
110 * Return Values: 1 = Valid length
115 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
116 __u16 required_length
)
118 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
120 if (unlikely(chunk_length
< required_length
))
126 /**********************************************************
127 * These are the state functions for handling chunk events.
128 **********************************************************/
131 * Process the final SHUTDOWN COMPLETE.
133 * Section: 4 (C) (diagram), 9.2
134 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
135 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
136 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
137 * should stop the T2-shutdown timer and remove all knowledge of the
138 * association (and thus the association enters the CLOSED state).
140 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
141 * C) Rules for packet carrying SHUTDOWN COMPLETE:
143 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
144 * if the Verification Tag field of the packet matches its own tag and
145 * the T bit is not set
147 * it is set to its peer's tag and the T bit is set in the Chunk
149 * Otherwise, the receiver MUST silently discard the packet
150 * and take no further action. An endpoint MUST ignore the
151 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
154 * (endpoint, asoc, chunk)
157 * (asoc, reply_msg, msg_up, timers, counters)
159 * The return value is the disposition of the chunk.
161 sctp_disposition_t
sctp_sf_do_4_C(const struct sctp_endpoint
*ep
,
162 const struct sctp_association
*asoc
,
163 const sctp_subtype_t type
,
165 sctp_cmd_seq_t
*commands
)
167 struct sctp_chunk
*chunk
= arg
;
168 struct sctp_ulpevent
*ev
;
170 /* RFC 2960 6.10 Bundling
172 * An endpoint MUST NOT bundle INIT, INIT ACK or
173 * SHUTDOWN COMPLETE with any other chunks.
175 if (!chunk
->singleton
)
176 return SCTP_DISPOSITION_VIOLATION
;
178 if (!sctp_vtag_verify_either(chunk
, asoc
))
179 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
181 /* RFC 2960 10.2 SCTP-to-ULP
183 * H) SHUTDOWN COMPLETE notification
185 * When SCTP completes the shutdown procedures (section 9.2) this
186 * notification is passed to the upper layer.
188 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
189 0, 0, 0, GFP_ATOMIC
);
193 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
195 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
196 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
197 * not the chunk should be discarded. If the endpoint is in
198 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
199 * T2-shutdown timer and remove all knowledge of the
200 * association (and thus the association enters the CLOSED
203 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
204 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
206 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
207 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
209 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
210 SCTP_STATE(SCTP_STATE_CLOSED
));
212 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
213 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
215 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
217 return SCTP_DISPOSITION_DELETE_TCB
;
220 return SCTP_DISPOSITION_NOMEM
;
224 * Respond to a normal INIT chunk.
225 * We are the side that is being asked for an association.
227 * Section: 5.1 Normal Establishment of an Association, B
228 * B) "Z" shall respond immediately with an INIT ACK chunk. The
229 * destination IP address of the INIT ACK MUST be set to the source
230 * IP address of the INIT to which this INIT ACK is responding. In
231 * the response, besides filling in other parameters, "Z" must set the
232 * Verification Tag field to Tag_A, and also provide its own
233 * Verification Tag (Tag_Z) in the Initiate Tag field.
235 * Verification Tag: Must be 0.
238 * (endpoint, asoc, chunk)
241 * (asoc, reply_msg, msg_up, timers, counters)
243 * The return value is the disposition of the chunk.
245 sctp_disposition_t
sctp_sf_do_5_1B_init(const struct sctp_endpoint
*ep
,
246 const struct sctp_association
*asoc
,
247 const sctp_subtype_t type
,
249 sctp_cmd_seq_t
*commands
)
251 struct sctp_chunk
*chunk
= arg
;
252 struct sctp_chunk
*repl
;
253 struct sctp_association
*new_asoc
;
254 struct sctp_chunk
*err_chunk
;
255 struct sctp_packet
*packet
;
256 sctp_unrecognized_param_t
*unk_param
;
261 * An endpoint MUST NOT bundle INIT, INIT ACK or
262 * SHUTDOWN COMPLETE with any other chunks.
265 * Furthermore, we require that the receiver of an INIT chunk MUST
266 * enforce these rules by silently discarding an arriving packet
267 * with an INIT chunk that is bundled with other chunks.
269 if (!chunk
->singleton
)
270 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
272 /* If the packet is an OOTB packet which is temporarily on the
273 * control endpoint, respond with an ABORT.
275 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
276 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
279 /* If the endpoint is not listening or if the number of associations
280 * on the TCP-style socket exceed the max backlog, respond with an
283 if (!sctp_sstate(sk
, LISTENING
) ||
284 (sctp_style(sk
, TCP
) &&
285 sk_acceptq_is_full(sk
)))
286 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
288 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
291 if (chunk
->sctp_hdr
->vtag
!= 0)
292 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
294 /* Make sure that the INIT chunk has a valid length.
295 * Normally, this would cause an ABORT with a Protocol Violation
296 * error, but since we don't have an association, we'll
297 * just discard the packet.
299 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
300 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
302 /* Verify the INIT chunk before processing it. */
304 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
305 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
307 /* This chunk contains fatal error. It is to be discarded.
308 * Send an ABORT, with causes if there is any.
311 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
312 (__u8
*)(err_chunk
->chunk_hdr
) +
313 sizeof(sctp_chunkhdr_t
),
314 ntohs(err_chunk
->chunk_hdr
->length
) -
315 sizeof(sctp_chunkhdr_t
));
317 sctp_chunk_free(err_chunk
);
320 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
321 SCTP_PACKET(packet
));
322 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
323 return SCTP_DISPOSITION_CONSUME
;
325 return SCTP_DISPOSITION_NOMEM
;
328 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
333 /* Grab the INIT header. */
334 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
336 /* Tag the variable length parameters. */
337 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
339 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
343 /* The call, sctp_process_init(), can fail on memory allocation. */
344 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
346 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
350 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
352 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
354 /* If there are errors need to be reported for unknown parameters,
355 * make sure to reserve enough room in the INIT ACK for them.
359 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
360 sizeof(sctp_chunkhdr_t
);
362 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
365 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
369 /* If there are errors need to be reported for unknown parameters,
370 * include them in the outgoing INIT ACK as "Unrecognized parameter"
374 /* Get the "Unrecognized parameter" parameter(s) out of the
375 * ERROR chunk generated by sctp_verify_init(). Since the
376 * error cause code for "unknown parameter" and the
377 * "Unrecognized parameter" type is the same, we can
378 * construct the parameters in INIT ACK by copying the
381 unk_param
= (sctp_unrecognized_param_t
*)
382 ((__u8
*)(err_chunk
->chunk_hdr
) +
383 sizeof(sctp_chunkhdr_t
));
384 /* Replace the cause code with the "Unrecognized parameter"
387 sctp_addto_chunk(repl
, len
, unk_param
);
388 sctp_chunk_free(err_chunk
);
391 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
394 * Note: After sending out INIT ACK with the State Cookie parameter,
395 * "Z" MUST NOT allocate any resources, nor keep any states for the
396 * new association. Otherwise, "Z" will be vulnerable to resource
399 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
401 return SCTP_DISPOSITION_DELETE_TCB
;
405 sctp_chunk_free(err_chunk
);
407 sctp_association_free(new_asoc
);
409 return SCTP_DISPOSITION_NOMEM
;
413 * Respond to a normal INIT ACK chunk.
414 * We are the side that is initiating the association.
416 * Section: 5.1 Normal Establishment of an Association, C
417 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
418 * timer and leave COOKIE-WAIT state. "A" shall then send the State
419 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
420 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
422 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
423 * DATA chunks, but it MUST be the first chunk in the packet and
424 * until the COOKIE ACK is returned the sender MUST NOT send any
425 * other packets to the peer.
427 * Verification Tag: 3.3.3
428 * If the value of the Initiate Tag in a received INIT ACK chunk is
429 * found to be 0, the receiver MUST treat it as an error and close the
430 * association by transmitting an ABORT.
433 * (endpoint, asoc, chunk)
436 * (asoc, reply_msg, msg_up, timers, counters)
438 * The return value is the disposition of the chunk.
440 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
441 const struct sctp_association
*asoc
,
442 const sctp_subtype_t type
,
444 sctp_cmd_seq_t
*commands
)
446 struct sctp_chunk
*chunk
= arg
;
447 sctp_init_chunk_t
*initchunk
;
449 struct sctp_chunk
*err_chunk
;
450 struct sctp_packet
*packet
;
451 sctp_disposition_t ret
;
453 if (!sctp_vtag_verify(chunk
, asoc
))
454 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
456 /* Make sure that the INIT-ACK chunk has a valid length */
457 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
458 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
461 * An endpoint MUST NOT bundle INIT, INIT ACK or
462 * SHUTDOWN COMPLETE with any other chunks.
464 if (!chunk
->singleton
)
465 return SCTP_DISPOSITION_VIOLATION
;
467 /* Grab the INIT header. */
468 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
470 init_tag
= ntohl(chunk
->subh
.init_hdr
->init_tag
);
472 /* Verification Tag: 3.3.3
473 * If the value of the Initiate Tag in a received INIT ACK
474 * chunk is found to be 0, the receiver MUST treat it as an
475 * error and close the association by transmitting an ABORT.
478 struct sctp_chunk
*reply
= sctp_make_abort(asoc
, chunk
, 0);
482 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
483 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
484 SCTP_STATE(SCTP_STATE_CLOSED
));
485 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
486 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
487 return SCTP_DISPOSITION_DELETE_TCB
;
490 /* Verify the INIT chunk before processing it. */
492 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
493 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
496 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
498 /* This chunk contains fatal error. It is to be discarded.
499 * Send an ABORT, with causes if there is any.
502 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
503 (__u8
*)(err_chunk
->chunk_hdr
) +
504 sizeof(sctp_chunkhdr_t
),
505 ntohs(err_chunk
->chunk_hdr
->length
) -
506 sizeof(sctp_chunkhdr_t
));
508 sctp_chunk_free(err_chunk
);
511 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
512 SCTP_PACKET(packet
));
513 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
514 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
515 SCTP_STATE(SCTP_STATE_CLOSED
));
516 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
518 return SCTP_DISPOSITION_CONSUME
;
520 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
521 SCTP_STATE(SCTP_STATE_CLOSED
));
522 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
524 return SCTP_DISPOSITION_NOMEM
;
527 ret
= sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
529 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
530 SCTP_STATE(SCTP_STATE_CLOSED
));
531 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
537 /* Tag the variable length parameters. Note that we never
538 * convert the parameters in an INIT chunk.
540 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
542 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
544 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
545 SCTP_PEER_INIT(initchunk
));
547 /* Reset init error count upon receipt of INIT-ACK. */
548 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
550 /* 5.1 C) "A" shall stop the T1-init timer and leave
551 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
552 * timer, and enter the COOKIE-ECHOED state.
554 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
555 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
556 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
557 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
558 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
559 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
561 /* 5.1 C) "A" shall then send the State Cookie received in the
562 * INIT ACK chunk in a COOKIE ECHO chunk, ...
564 /* If there is any errors to report, send the ERROR chunk generated
565 * for unknown parameters as well.
567 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
568 SCTP_CHUNK(err_chunk
));
570 return SCTP_DISPOSITION_CONSUME
;
573 return SCTP_DISPOSITION_NOMEM
;
577 * Respond to a normal COOKIE ECHO chunk.
578 * We are the side that is being asked for an association.
580 * Section: 5.1 Normal Establishment of an Association, D
581 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
582 * with a COOKIE ACK chunk after building a TCB and moving to
583 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
584 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
585 * chunk MUST be the first chunk in the packet.
587 * IMPLEMENTATION NOTE: An implementation may choose to send the
588 * Communication Up notification to the SCTP user upon reception
589 * of a valid COOKIE ECHO chunk.
591 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
592 * D) Rules for packet carrying a COOKIE ECHO
594 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
595 * Initial Tag received in the INIT ACK.
597 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
600 * (endpoint, asoc, chunk)
603 * (asoc, reply_msg, msg_up, timers, counters)
605 * The return value is the disposition of the chunk.
607 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
608 const struct sctp_association
*asoc
,
609 const sctp_subtype_t type
, void *arg
,
610 sctp_cmd_seq_t
*commands
)
612 struct sctp_chunk
*chunk
= arg
;
613 struct sctp_association
*new_asoc
;
614 sctp_init_chunk_t
*peer_init
;
615 struct sctp_chunk
*repl
;
616 struct sctp_ulpevent
*ev
;
618 struct sctp_chunk
*err_chk_p
;
620 /* If the packet is an OOTB packet which is temporarily on the
621 * control endpoint, respond with an ABORT.
623 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
624 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
626 /* Make sure that the COOKIE_ECHO chunk has a valid length.
627 * In this case, we check that we have enough for at least a
628 * chunk header. More detailed verification is done
629 * in sctp_unpack_cookie().
631 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
632 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
634 /* "Decode" the chunk. We have no optional parameters so we
637 chunk
->subh
.cookie_hdr
=
638 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
640 ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
));
642 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
643 * "Z" will reply with a COOKIE ACK chunk after building a TCB
644 * and moving to the ESTABLISHED state.
646 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
650 * If the re-build failed, what is the proper error path
653 * [We should abort the association. --piggy]
656 /* FIXME: Several errors are possible. A bad cookie should
657 * be silently discarded, but think about logging it too.
660 case -SCTP_IERROR_NOMEM
:
663 case -SCTP_IERROR_STALE_COOKIE
:
664 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
666 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
668 case -SCTP_IERROR_BAD_SIG
:
670 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
674 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
675 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
676 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
677 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
678 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
679 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
681 if (new_asoc
->autoclose
)
682 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
683 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
685 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
687 /* Re-build the bind address for the association is done in
688 * the sctp_unpack_cookie() already.
690 /* This is a brand-new association, so these are not yet side
691 * effects--it is safe to run them here.
693 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
695 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
696 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
697 peer_init
, GFP_ATOMIC
))
700 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
704 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
706 /* RFC 2960 5.1 Normal Establishment of an Association
708 * D) IMPLEMENTATION NOTE: An implementation may choose to
709 * send the Communication Up notification to the SCTP user
710 * upon reception of a valid COOKIE ECHO chunk.
712 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
713 new_asoc
->c
.sinit_num_ostreams
,
714 new_asoc
->c
.sinit_max_instreams
,
719 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
721 /* Sockets API Draft Section 5.3.1.6
722 * When a peer sends a Adaption Layer Indication parameter , SCTP
723 * delivers this notification to inform the application that of the
724 * peers requested adaption layer.
726 if (new_asoc
->peer
.adaption_ind
) {
727 ev
= sctp_ulpevent_make_adaption_indication(new_asoc
,
732 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
736 return SCTP_DISPOSITION_CONSUME
;
739 sctp_chunk_free(repl
);
742 sctp_association_free(new_asoc
);
744 return SCTP_DISPOSITION_NOMEM
;
748 * Respond to a normal COOKIE ACK chunk.
749 * We are the side that is being asked for an association.
751 * RFC 2960 5.1 Normal Establishment of an Association
753 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
754 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
755 * timer. It may also notify its ULP about the successful
756 * establishment of the association with a Communication Up
757 * notification (see Section 10).
761 * (endpoint, asoc, chunk)
764 * (asoc, reply_msg, msg_up, timers, counters)
766 * The return value is the disposition of the chunk.
768 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
769 const struct sctp_association
*asoc
,
770 const sctp_subtype_t type
, void *arg
,
771 sctp_cmd_seq_t
*commands
)
773 struct sctp_chunk
*chunk
= arg
;
774 struct sctp_ulpevent
*ev
;
776 if (!sctp_vtag_verify(chunk
, asoc
))
777 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
779 /* Verify that the chunk length for the COOKIE-ACK is OK.
780 * If we don't do this, any bundled chunks may be junked.
782 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
783 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
786 /* Reset init error count upon receipt of COOKIE-ACK,
787 * to avoid problems with the managemement of this
788 * counter in stale cookie situations when a transition back
789 * from the COOKIE-ECHOED state to the COOKIE-WAIT
790 * state is performed.
792 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
794 /* RFC 2960 5.1 Normal Establishment of an Association
796 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
797 * from the COOKIE-ECHOED state to the ESTABLISHED state,
798 * stopping the T1-cookie timer.
800 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
801 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
802 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
803 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
804 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
805 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
806 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
808 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
809 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
810 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
812 /* It may also notify its ULP about the successful
813 * establishment of the association with a Communication Up
814 * notification (see Section 10).
816 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
817 0, asoc
->c
.sinit_num_ostreams
,
818 asoc
->c
.sinit_max_instreams
,
824 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
826 /* Sockets API Draft Section 5.3.1.6
827 * When a peer sends a Adaption Layer Indication parameter , SCTP
828 * delivers this notification to inform the application that of the
829 * peers requested adaption layer.
831 if (asoc
->peer
.adaption_ind
) {
832 ev
= sctp_ulpevent_make_adaption_indication(asoc
, GFP_ATOMIC
);
836 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
840 return SCTP_DISPOSITION_CONSUME
;
842 return SCTP_DISPOSITION_NOMEM
;
845 /* Generate and sendout a heartbeat packet. */
846 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
847 const struct sctp_association
*asoc
,
848 const sctp_subtype_t type
,
850 sctp_cmd_seq_t
*commands
)
852 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
853 struct sctp_chunk
*reply
;
854 sctp_sender_hb_info_t hbinfo
;
857 hbinfo
.param_hdr
.type
= SCTP_PARAM_HEARTBEAT_INFO
;
858 hbinfo
.param_hdr
.length
= htons(sizeof(sctp_sender_hb_info_t
));
859 hbinfo
.daddr
= transport
->ipaddr
;
860 hbinfo
.sent_at
= jiffies
;
862 /* Send a heartbeat to our peer. */
863 paylen
= sizeof(sctp_sender_hb_info_t
);
864 reply
= sctp_make_heartbeat(asoc
, transport
, &hbinfo
, paylen
);
866 return SCTP_DISPOSITION_NOMEM
;
868 /* Set rto_pending indicating that an RTT measurement
869 * is started with this heartbeat chunk.
871 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
872 SCTP_TRANSPORT(transport
));
874 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
875 return SCTP_DISPOSITION_CONSUME
;
878 /* Generate a HEARTBEAT packet on the given transport. */
879 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
880 const struct sctp_association
*asoc
,
881 const sctp_subtype_t type
,
883 sctp_cmd_seq_t
*commands
)
885 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
887 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
888 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
889 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
890 SCTP_U32(SCTP_ERROR_NO_ERROR
));
891 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
892 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
893 return SCTP_DISPOSITION_DELETE_TCB
;
897 * The Sender-specific Heartbeat Info field should normally include
898 * information about the sender's current time when this HEARTBEAT
899 * chunk is sent and the destination transport address to which this
900 * HEARTBEAT is sent (see Section 8.3).
903 if (transport
->param_flags
& SPP_HB_ENABLE
) {
904 if (SCTP_DISPOSITION_NOMEM
==
905 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
907 return SCTP_DISPOSITION_NOMEM
;
908 /* Set transport error counter and association error counter
909 * when sending heartbeat.
911 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_RESET
,
912 SCTP_TRANSPORT(transport
));
914 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
915 SCTP_TRANSPORT(transport
));
917 return SCTP_DISPOSITION_CONSUME
;
921 * Process an heartbeat request.
923 * Section: 8.3 Path Heartbeat
924 * The receiver of the HEARTBEAT should immediately respond with a
925 * HEARTBEAT ACK that contains the Heartbeat Information field copied
926 * from the received HEARTBEAT chunk.
928 * Verification Tag: 8.5 Verification Tag [Normal verification]
929 * When receiving an SCTP packet, the endpoint MUST ensure that the
930 * value in the Verification Tag field of the received SCTP packet
931 * matches its own Tag. If the received Verification Tag value does not
932 * match the receiver's own tag value, the receiver shall silently
933 * discard the packet and shall not process it any further except for
934 * those cases listed in Section 8.5.1 below.
937 * (endpoint, asoc, chunk)
940 * (asoc, reply_msg, msg_up, timers, counters)
942 * The return value is the disposition of the chunk.
944 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
945 const struct sctp_association
*asoc
,
946 const sctp_subtype_t type
,
948 sctp_cmd_seq_t
*commands
)
950 struct sctp_chunk
*chunk
= arg
;
951 struct sctp_chunk
*reply
;
954 if (!sctp_vtag_verify(chunk
, asoc
))
955 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
957 /* Make sure that the HEARTBEAT chunk has a valid length. */
958 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
959 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
962 /* 8.3 The receiver of the HEARTBEAT should immediately
963 * respond with a HEARTBEAT ACK that contains the Heartbeat
964 * Information field copied from the received HEARTBEAT chunk.
966 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
967 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
968 skb_pull(chunk
->skb
, paylen
);
970 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
971 chunk
->subh
.hb_hdr
, paylen
);
975 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
976 return SCTP_DISPOSITION_CONSUME
;
979 return SCTP_DISPOSITION_NOMEM
;
983 * Process the returning HEARTBEAT ACK.
985 * Section: 8.3 Path Heartbeat
986 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
987 * should clear the error counter of the destination transport
988 * address to which the HEARTBEAT was sent, and mark the destination
989 * transport address as active if it is not so marked. The endpoint may
990 * optionally report to the upper layer when an inactive destination
991 * address is marked as active due to the reception of the latest
992 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
993 * clear the association overall error count as well (as defined
996 * The receiver of the HEARTBEAT ACK should also perform an RTT
997 * measurement for that destination transport address using the time
998 * value carried in the HEARTBEAT ACK chunk.
1000 * Verification Tag: 8.5 Verification Tag [Normal verification]
1003 * (endpoint, asoc, chunk)
1006 * (asoc, reply_msg, msg_up, timers, counters)
1008 * The return value is the disposition of the chunk.
1010 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1011 const struct sctp_association
*asoc
,
1012 const sctp_subtype_t type
,
1014 sctp_cmd_seq_t
*commands
)
1016 struct sctp_chunk
*chunk
= arg
;
1017 union sctp_addr from_addr
;
1018 struct sctp_transport
*link
;
1019 sctp_sender_hb_info_t
*hbinfo
;
1020 unsigned long max_interval
;
1022 if (!sctp_vtag_verify(chunk
, asoc
))
1023 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1025 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1026 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1027 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1030 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1031 from_addr
= hbinfo
->daddr
;
1032 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1034 /* This should never happen, but lets log it if so. */
1035 if (unlikely(!link
)) {
1036 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1038 "%s association %p could not find address "
1042 NIP6(from_addr
.v6
.sin6_addr
));
1045 "%s association %p could not find address "
1049 NIPQUAD(from_addr
.v4
.sin_addr
.s_addr
));
1051 return SCTP_DISPOSITION_DISCARD
;
1054 max_interval
= link
->hbinterval
+ link
->rto
;
1056 /* Check if the timestamp looks valid. */
1057 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1058 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1059 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1060 "received for transport: %p\n",
1061 __FUNCTION__
, link
);
1062 return SCTP_DISPOSITION_DISCARD
;
1065 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1066 * the HEARTBEAT should clear the error counter of the
1067 * destination transport address to which the HEARTBEAT was
1068 * sent and mark the destination transport address as active if
1069 * it is not so marked.
1071 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1073 return SCTP_DISPOSITION_CONSUME
;
1076 /* Helper function to send out an abort for the restart
1079 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1080 struct sctp_chunk
*init
,
1081 sctp_cmd_seq_t
*commands
)
1084 struct sctp_packet
*pkt
;
1085 union sctp_addr_param
*addrparm
;
1086 struct sctp_errhdr
*errhdr
;
1087 struct sctp_endpoint
*ep
;
1088 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1089 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1091 /* Build the error on the stack. We are way to malloc crazy
1092 * throughout the code today.
1094 errhdr
= (struct sctp_errhdr
*)buffer
;
1095 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1097 /* Copy into a parm format. */
1098 len
= af
->to_addr_param(ssa
, addrparm
);
1099 len
+= sizeof(sctp_errhdr_t
);
1101 errhdr
->cause
= SCTP_ERROR_RESTART
;
1102 errhdr
->length
= htons(len
);
1104 /* Assign to the control socket. */
1105 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1107 /* Association is NULL since this may be a restart attack and we
1108 * want to send back the attacker's vtag.
1110 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1114 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1116 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1118 /* Discard the rest of the inbound packet. */
1119 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1122 /* Even if there is no memory, treat as a failure so
1123 * the packet will get dropped.
1128 /* A restart is occurring, check to make sure no new addresses
1129 * are being added as we may be under a takeover attack.
1131 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1132 const struct sctp_association
*asoc
,
1133 struct sctp_chunk
*init
,
1134 sctp_cmd_seq_t
*commands
)
1136 struct sctp_transport
*new_addr
, *addr
;
1137 struct list_head
*pos
, *pos2
;
1140 /* Implementor's Guide - Sectin 5.2.2
1142 * Before responding the endpoint MUST check to see if the
1143 * unexpected INIT adds new addresses to the association. If new
1144 * addresses are added to the association, the endpoint MUST respond
1148 /* Search through all current addresses and make sure
1149 * we aren't adding any new ones.
1154 list_for_each(pos
, &new_asoc
->peer
.transport_addr_list
) {
1155 new_addr
= list_entry(pos
, struct sctp_transport
, transports
);
1157 list_for_each(pos2
, &asoc
->peer
.transport_addr_list
) {
1158 addr
= list_entry(pos2
, struct sctp_transport
,
1160 if (sctp_cmp_addr_exact(&new_addr
->ipaddr
,
1170 /* If a new address was added, ABORT the sender. */
1171 if (!found
&& new_addr
) {
1172 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
, commands
);
1175 /* Return success if all addresses were found. */
1179 /* Populate the verification/tie tags based on overlapping INIT
1182 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1184 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1185 const struct sctp_association
*asoc
)
1187 switch (asoc
->state
) {
1189 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1191 case SCTP_STATE_COOKIE_WAIT
:
1192 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1193 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1194 new_asoc
->c
.peer_ttag
= 0;
1197 case SCTP_STATE_COOKIE_ECHOED
:
1198 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1199 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1200 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1203 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1204 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1207 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1208 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1212 /* Other parameters for the endpoint SHOULD be copied from the
1213 * existing parameters of the association (e.g. number of
1214 * outbound streams) into the INIT ACK and cookie.
1216 new_asoc
->rwnd
= asoc
->rwnd
;
1217 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1218 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1219 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1223 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1226 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1228 * Returns value representing action to be taken. These action values
1229 * correspond to Action/Description values in RFC 2960, Table 2.
1231 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1232 const struct sctp_association
*asoc
)
1234 /* In this case, the peer may have restarted. */
1235 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1236 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1237 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1238 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1241 /* Collision case B. */
1242 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1243 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1244 (0 == asoc
->c
.peer_vtag
))) {
1248 /* Collision case D. */
1249 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1250 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1253 /* Collision case C. */
1254 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1255 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1256 (0 == new_asoc
->c
.my_ttag
) &&
1257 (0 == new_asoc
->c
.peer_ttag
))
1260 /* No match to any of the special cases; discard this packet. */
1264 /* Common helper routine for both duplicate and simulataneous INIT
1267 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1268 const struct sctp_endpoint
*ep
,
1269 const struct sctp_association
*asoc
,
1270 const sctp_subtype_t type
,
1271 void *arg
, sctp_cmd_seq_t
*commands
)
1273 sctp_disposition_t retval
;
1274 struct sctp_chunk
*chunk
= arg
;
1275 struct sctp_chunk
*repl
;
1276 struct sctp_association
*new_asoc
;
1277 struct sctp_chunk
*err_chunk
;
1278 struct sctp_packet
*packet
;
1279 sctp_unrecognized_param_t
*unk_param
;
1283 * An endpoint MUST NOT bundle INIT, INIT ACK or
1284 * SHUTDOWN COMPLETE with any other chunks.
1287 * Furthermore, we require that the receiver of an INIT chunk MUST
1288 * enforce these rules by silently discarding an arriving packet
1289 * with an INIT chunk that is bundled with other chunks.
1291 if (!chunk
->singleton
)
1292 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1294 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1297 if (chunk
->sctp_hdr
->vtag
!= 0)
1298 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1300 /* Make sure that the INIT chunk has a valid length.
1301 * In this case, we generate a protocol violation since we have
1302 * an association established.
1304 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1305 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1307 /* Grab the INIT header. */
1308 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1310 /* Tag the variable length parameters. */
1311 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1313 /* Verify the INIT chunk before processing it. */
1315 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1316 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1318 /* This chunk contains fatal error. It is to be discarded.
1319 * Send an ABORT, with causes if there is any.
1322 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1323 (__u8
*)(err_chunk
->chunk_hdr
) +
1324 sizeof(sctp_chunkhdr_t
),
1325 ntohs(err_chunk
->chunk_hdr
->length
) -
1326 sizeof(sctp_chunkhdr_t
));
1329 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1330 SCTP_PACKET(packet
));
1331 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1332 retval
= SCTP_DISPOSITION_CONSUME
;
1334 retval
= SCTP_DISPOSITION_NOMEM
;
1338 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1344 * Other parameters for the endpoint SHOULD be copied from the
1345 * existing parameters of the association (e.g. number of
1346 * outbound streams) into the INIT ACK and cookie.
1347 * FIXME: We are copying parameters from the endpoint not the
1350 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1354 /* In the outbound INIT ACK the endpoint MUST copy its current
1355 * Verification Tag and Peers Verification tag into a reserved
1356 * place (local tie-tag and per tie-tag) within the state cookie.
1358 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1360 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1362 retval
= SCTP_DISPOSITION_NOMEM
;
1366 /* Make sure no new addresses are being added during the
1367 * restart. Do not do this check for COOKIE-WAIT state,
1368 * since there are no peer addresses to check against.
1369 * Upon return an ABORT will have been sent if needed.
1371 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1372 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1374 retval
= SCTP_DISPOSITION_CONSUME
;
1379 sctp_tietags_populate(new_asoc
, asoc
);
1381 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1383 /* If there are errors need to be reported for unknown parameters,
1384 * make sure to reserve enough room in the INIT ACK for them.
1388 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1389 sizeof(sctp_chunkhdr_t
);
1392 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
1395 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1399 /* If there are errors need to be reported for unknown parameters,
1400 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1404 /* Get the "Unrecognized parameter" parameter(s) out of the
1405 * ERROR chunk generated by sctp_verify_init(). Since the
1406 * error cause code for "unknown parameter" and the
1407 * "Unrecognized parameter" type is the same, we can
1408 * construct the parameters in INIT ACK by copying the
1409 * ERROR causes over.
1411 unk_param
= (sctp_unrecognized_param_t
*)
1412 ((__u8
*)(err_chunk
->chunk_hdr
) +
1413 sizeof(sctp_chunkhdr_t
));
1414 /* Replace the cause code with the "Unrecognized parameter"
1417 sctp_addto_chunk(repl
, len
, unk_param
);
1420 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1421 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1424 * Note: After sending out INIT ACK with the State Cookie parameter,
1425 * "Z" MUST NOT allocate any resources for this new association.
1426 * Otherwise, "Z" will be vulnerable to resource attacks.
1428 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1429 retval
= SCTP_DISPOSITION_CONSUME
;
1433 sctp_chunk_free(err_chunk
);
1436 retval
= SCTP_DISPOSITION_NOMEM
;
1440 sctp_association_free(new_asoc
);
1445 * Handle simultanous INIT.
1446 * This means we started an INIT and then we got an INIT request from
1449 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1450 * This usually indicates an initialization collision, i.e., each
1451 * endpoint is attempting, at about the same time, to establish an
1452 * association with the other endpoint.
1454 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1455 * endpoint MUST respond with an INIT ACK using the same parameters it
1456 * sent in its original INIT chunk (including its Verification Tag,
1457 * unchanged). These original parameters are combined with those from the
1458 * newly received INIT chunk. The endpoint shall also generate a State
1459 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1460 * INIT to calculate the State Cookie.
1462 * After that, the endpoint MUST NOT change its state, the T1-init
1463 * timer shall be left running and the corresponding TCB MUST NOT be
1464 * destroyed. The normal procedures for handling State Cookies when
1465 * a TCB exists will resolve the duplicate INITs to a single association.
1467 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1468 * its Tie-Tags with the Tag information of itself and its peer (see
1469 * section 5.2.2 for a description of the Tie-Tags).
1471 * Verification Tag: Not explicit, but an INIT can not have a valid
1472 * verification tag, so we skip the check.
1475 * (endpoint, asoc, chunk)
1478 * (asoc, reply_msg, msg_up, timers, counters)
1480 * The return value is the disposition of the chunk.
1482 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1483 const struct sctp_association
*asoc
,
1484 const sctp_subtype_t type
,
1486 sctp_cmd_seq_t
*commands
)
1488 /* Call helper to do the real work for both simulataneous and
1489 * duplicate INIT chunk handling.
1491 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1495 * Handle duplicated INIT messages. These are usually delayed
1498 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1499 * COOKIE-ECHOED and COOKIE-WAIT
1501 * Unless otherwise stated, upon reception of an unexpected INIT for
1502 * this association, the endpoint shall generate an INIT ACK with a
1503 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1504 * current Verification Tag and peer's Verification Tag into a reserved
1505 * place within the state cookie. We shall refer to these locations as
1506 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1507 * containing this INIT ACK MUST carry a Verification Tag value equal to
1508 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1509 * MUST contain a new Initiation Tag (randomly generated see Section
1510 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1511 * existing parameters of the association (e.g. number of outbound
1512 * streams) into the INIT ACK and cookie.
1514 * After sending out the INIT ACK, the endpoint shall take no further
1515 * actions, i.e., the existing association, including its current state,
1516 * and the corresponding TCB MUST NOT be changed.
1518 * Note: Only when a TCB exists and the association is not in a COOKIE-
1519 * WAIT state are the Tie-Tags populated. For a normal association INIT
1520 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1521 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1522 * State Cookie are populated as specified in section 5.2.1.
1524 * Verification Tag: Not specified, but an INIT has no way of knowing
1525 * what the verification tag could be, so we ignore it.
1528 * (endpoint, asoc, chunk)
1531 * (asoc, reply_msg, msg_up, timers, counters)
1533 * The return value is the disposition of the chunk.
1535 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1536 const struct sctp_association
*asoc
,
1537 const sctp_subtype_t type
,
1539 sctp_cmd_seq_t
*commands
)
1541 /* Call helper to do the real work for both simulataneous and
1542 * duplicate INIT chunk handling.
1544 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1549 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1552 * A) In this case, the peer may have restarted.
1554 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1555 const struct sctp_association
*asoc
,
1556 struct sctp_chunk
*chunk
,
1557 sctp_cmd_seq_t
*commands
,
1558 struct sctp_association
*new_asoc
)
1560 sctp_init_chunk_t
*peer_init
;
1561 struct sctp_ulpevent
*ev
;
1562 struct sctp_chunk
*repl
;
1563 struct sctp_chunk
*err
;
1564 sctp_disposition_t disposition
;
1566 /* new_asoc is a brand-new association, so these are not yet
1567 * side effects--it is safe to run them here.
1569 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1571 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1572 sctp_source(chunk
), peer_init
,
1576 /* Make sure no new addresses are being added during the
1577 * restart. Though this is a pretty complicated attack
1578 * since you'd have to get inside the cookie.
1580 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1581 return SCTP_DISPOSITION_CONSUME
;
1584 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1585 * the peer has restarted (Action A), it MUST NOT setup a new
1586 * association but instead resend the SHUTDOWN ACK and send an ERROR
1587 * chunk with a "Cookie Received while Shutting Down" error cause to
1590 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1591 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1592 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1594 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1597 err
= sctp_make_op_error(asoc
, chunk
,
1598 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1601 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1604 return SCTP_DISPOSITION_CONSUME
;
1607 /* For now, fail any unsent/unacked data. Consider the optional
1608 * choice of resending of this data.
1610 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1612 /* Update the content of current association. */
1613 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1615 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1619 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1621 /* Report association restart to upper layer. */
1622 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1623 new_asoc
->c
.sinit_num_ostreams
,
1624 new_asoc
->c
.sinit_max_instreams
,
1629 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1630 return SCTP_DISPOSITION_CONSUME
;
1633 sctp_chunk_free(repl
);
1635 return SCTP_DISPOSITION_NOMEM
;
1638 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1641 * B) In this case, both sides may be attempting to start an association
1642 * at about the same time but the peer endpoint started its INIT
1643 * after responding to the local endpoint's INIT
1645 /* This case represents an initialization collision. */
1646 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1647 const struct sctp_association
*asoc
,
1648 struct sctp_chunk
*chunk
,
1649 sctp_cmd_seq_t
*commands
,
1650 struct sctp_association
*new_asoc
)
1652 sctp_init_chunk_t
*peer_init
;
1653 struct sctp_ulpevent
*ev
;
1654 struct sctp_chunk
*repl
;
1656 /* new_asoc is a brand-new association, so these are not yet
1657 * side effects--it is safe to run them here.
1659 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1660 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1661 sctp_source(chunk
), peer_init
,
1665 /* Update the content of current association. */
1666 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1667 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1668 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1669 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1670 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1672 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1676 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1677 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1679 /* RFC 2960 5.1 Normal Establishment of an Association
1681 * D) IMPLEMENTATION NOTE: An implementation may choose to
1682 * send the Communication Up notification to the SCTP user
1683 * upon reception of a valid COOKIE ECHO chunk.
1685 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
, 0,
1686 new_asoc
->c
.sinit_num_ostreams
,
1687 new_asoc
->c
.sinit_max_instreams
,
1692 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1694 /* Sockets API Draft Section 5.3.1.6
1695 * When a peer sends a Adaption Layer Indication parameter , SCTP
1696 * delivers this notification to inform the application that of the
1697 * peers requested adaption layer.
1699 if (asoc
->peer
.adaption_ind
) {
1700 ev
= sctp_ulpevent_make_adaption_indication(asoc
, GFP_ATOMIC
);
1704 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1708 return SCTP_DISPOSITION_CONSUME
;
1711 sctp_chunk_free(repl
);
1713 return SCTP_DISPOSITION_NOMEM
;
1716 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1719 * C) In this case, the local endpoint's cookie has arrived late.
1720 * Before it arrived, the local endpoint sent an INIT and received an
1721 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1722 * but a new tag of its own.
1724 /* This case represents an initialization collision. */
1725 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1726 const struct sctp_association
*asoc
,
1727 struct sctp_chunk
*chunk
,
1728 sctp_cmd_seq_t
*commands
,
1729 struct sctp_association
*new_asoc
)
1731 /* The cookie should be silently discarded.
1732 * The endpoint SHOULD NOT change states and should leave
1733 * any timers running.
1735 return SCTP_DISPOSITION_DISCARD
;
1738 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1742 * D) When both local and remote tags match the endpoint should always
1743 * enter the ESTABLISHED state, if it has not already done so.
1745 /* This case represents an initialization collision. */
1746 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1747 const struct sctp_association
*asoc
,
1748 struct sctp_chunk
*chunk
,
1749 sctp_cmd_seq_t
*commands
,
1750 struct sctp_association
*new_asoc
)
1752 struct sctp_ulpevent
*ev
= NULL
;
1753 struct sctp_chunk
*repl
;
1755 /* Clarification from Implementor's Guide:
1756 * D) When both local and remote tags match the endpoint should
1757 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1758 * It should stop any cookie timer that may be running and send
1762 /* Don't accidentally move back into established state. */
1763 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1764 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1765 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1766 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1767 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1768 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1769 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1772 /* RFC 2960 5.1 Normal Establishment of an Association
1774 * D) IMPLEMENTATION NOTE: An implementation may choose
1775 * to send the Communication Up notification to the
1776 * SCTP user upon reception of a valid COOKIE
1779 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0,
1781 new_asoc
->c
.sinit_num_ostreams
,
1782 new_asoc
->c
.sinit_max_instreams
,
1786 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1789 /* Sockets API Draft Section 5.3.1.6
1790 * When a peer sends a Adaption Layer Indication parameter,
1791 * SCTP delivers this notification to inform the application
1792 * that of the peers requested adaption layer.
1794 if (new_asoc
->peer
.adaption_ind
) {
1795 ev
= sctp_ulpevent_make_adaption_indication(new_asoc
,
1800 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1804 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1806 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1810 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1811 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1813 return SCTP_DISPOSITION_CONSUME
;
1817 sctp_ulpevent_free(ev
);
1818 return SCTP_DISPOSITION_NOMEM
;
1822 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1823 * chunk was retransmitted and then delayed in the network.
1825 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1827 * Verification Tag: None. Do cookie validation.
1830 * (endpoint, asoc, chunk)
1833 * (asoc, reply_msg, msg_up, timers, counters)
1835 * The return value is the disposition of the chunk.
1837 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1838 const struct sctp_association
*asoc
,
1839 const sctp_subtype_t type
,
1841 sctp_cmd_seq_t
*commands
)
1843 sctp_disposition_t retval
;
1844 struct sctp_chunk
*chunk
= arg
;
1845 struct sctp_association
*new_asoc
;
1848 struct sctp_chunk
*err_chk_p
;
1850 /* Make sure that the chunk has a valid length from the protocol
1851 * perspective. In this case check to make sure we have at least
1852 * enough for the chunk header. Cookie length verification is
1855 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1856 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1859 /* "Decode" the chunk. We have no optional parameters so we
1860 * are in good shape.
1862 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1863 skb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1864 sizeof(sctp_chunkhdr_t
));
1866 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1867 * of a duplicate COOKIE ECHO match the Verification Tags of the
1868 * current association, consider the State Cookie valid even if
1869 * the lifespan is exceeded.
1871 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1875 * If the re-build failed, what is the proper error path
1878 * [We should abort the association. --piggy]
1881 /* FIXME: Several errors are possible. A bad cookie should
1882 * be silently discarded, but think about logging it too.
1885 case -SCTP_IERROR_NOMEM
:
1888 case -SCTP_IERROR_STALE_COOKIE
:
1889 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
1891 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1892 case -SCTP_IERROR_BAD_SIG
:
1894 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1898 /* Compare the tie_tag in cookie with the verification tag of
1899 * current association.
1901 action
= sctp_tietags_compare(new_asoc
, asoc
);
1904 case 'A': /* Association restart. */
1905 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
1909 case 'B': /* Collision case B. */
1910 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
1914 case 'C': /* Collision case C. */
1915 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
1919 case 'D': /* Collision case D. */
1920 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
1924 default: /* Discard packet for all others. */
1925 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1929 /* Delete the tempory new association. */
1930 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1931 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1936 return SCTP_DISPOSITION_NOMEM
;
1940 * Process an ABORT. (SHUTDOWN-PENDING state)
1942 * See sctp_sf_do_9_1_abort().
1944 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
1945 const struct sctp_endpoint
*ep
,
1946 const struct sctp_association
*asoc
,
1947 const sctp_subtype_t type
,
1949 sctp_cmd_seq_t
*commands
)
1951 struct sctp_chunk
*chunk
= arg
;
1953 if (!sctp_vtag_verify_either(chunk
, asoc
))
1954 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1956 /* Make sure that the ABORT chunk has a valid length.
1957 * Since this is an ABORT chunk, we have to discard it
1958 * because of the following text:
1959 * RFC 2960, Section 3.3.7
1960 * If an endpoint receives an ABORT with a format error or for an
1961 * association that doesn't exist, it MUST silently discard it.
1962 * Becasue the length is "invalid", we can't really discard just
1963 * as we do not know its true length. So, to be safe, discard the
1966 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
1967 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1969 /* Stop the T5-shutdown guard timer. */
1970 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1971 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
1973 return sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
1977 * Process an ABORT. (SHUTDOWN-SENT state)
1979 * See sctp_sf_do_9_1_abort().
1981 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
1982 const struct sctp_association
*asoc
,
1983 const sctp_subtype_t type
,
1985 sctp_cmd_seq_t
*commands
)
1987 struct sctp_chunk
*chunk
= arg
;
1989 if (!sctp_vtag_verify_either(chunk
, asoc
))
1990 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1992 /* Make sure that the ABORT chunk has a valid length.
1993 * Since this is an ABORT chunk, we have to discard it
1994 * because of the following text:
1995 * RFC 2960, Section 3.3.7
1996 * If an endpoint receives an ABORT with a format error or for an
1997 * association that doesn't exist, it MUST silently discard it.
1998 * Becasue the length is "invalid", we can't really discard just
1999 * as we do not know its true length. So, to be safe, discard the
2002 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2003 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2005 /* Stop the T2-shutdown timer. */
2006 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2007 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2009 /* Stop the T5-shutdown guard timer. */
2010 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2011 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2013 return sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2017 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2019 * See sctp_sf_do_9_1_abort().
2021 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2022 const struct sctp_endpoint
*ep
,
2023 const struct sctp_association
*asoc
,
2024 const sctp_subtype_t type
,
2026 sctp_cmd_seq_t
*commands
)
2028 /* The same T2 timer, so we should be able to use
2029 * common function with the SHUTDOWN-SENT state.
2031 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2035 * Handle an Error received in COOKIE_ECHOED state.
2037 * Only handle the error type of stale COOKIE Error, the other errors will
2041 * (endpoint, asoc, chunk)
2044 * (asoc, reply_msg, msg_up, timers, counters)
2046 * The return value is the disposition of the chunk.
2048 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2049 const struct sctp_association
*asoc
,
2050 const sctp_subtype_t type
,
2052 sctp_cmd_seq_t
*commands
)
2054 struct sctp_chunk
*chunk
= arg
;
2057 if (!sctp_vtag_verify(chunk
, asoc
))
2058 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2060 /* Make sure that the ERROR chunk has a valid length.
2061 * The parameter walking depends on this as well.
2063 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2064 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2067 /* Process the error here */
2068 /* FUTURE FIXME: When PR-SCTP related and other optional
2069 * parms are emitted, this will have to change to handle multiple
2072 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2073 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2074 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2078 /* It is possible to have malformed error causes, and that
2079 * will cause us to end the walk early. However, since
2080 * we are discarding the packet, there should be no adverse
2083 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2087 * Handle a Stale COOKIE Error
2089 * Section: 5.2.6 Handle Stale COOKIE Error
2090 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2091 * one of the following three alternatives.
2093 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2094 * Preservative parameter requesting an extension to the lifetime of
2095 * the State Cookie. When calculating the time extension, an
2096 * implementation SHOULD use the RTT information measured based on the
2097 * previous COOKIE ECHO / ERROR exchange, and should add no more
2098 * than 1 second beyond the measured RTT, due to long State Cookie
2099 * lifetimes making the endpoint more subject to a replay attack.
2101 * Verification Tag: Not explicit, but safe to ignore.
2104 * (endpoint, asoc, chunk)
2107 * (asoc, reply_msg, msg_up, timers, counters)
2109 * The return value is the disposition of the chunk.
2111 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2112 const struct sctp_association
*asoc
,
2113 const sctp_subtype_t type
,
2115 sctp_cmd_seq_t
*commands
)
2117 struct sctp_chunk
*chunk
= arg
;
2119 sctp_cookie_preserve_param_t bht
;
2121 struct sctp_chunk
*reply
;
2122 struct sctp_bind_addr
*bp
;
2123 int attempts
= asoc
->init_err_counter
+ 1;
2125 if (attempts
> asoc
->max_init_attempts
) {
2126 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2127 SCTP_U32(SCTP_ERROR_STALE_COOKIE
));
2128 return SCTP_DISPOSITION_DELETE_TCB
;
2131 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2133 /* When calculating the time extension, an implementation
2134 * SHOULD use the RTT information measured based on the
2135 * previous COOKIE ECHO / ERROR exchange, and should add no
2136 * more than 1 second beyond the measured RTT, due to long
2137 * State Cookie lifetimes making the endpoint more subject to
2139 * Measure of Staleness's unit is usec. (1/1000000 sec)
2140 * Suggested Cookie Life-span Increment's unit is msec.
2142 * In general, if you use the suggested cookie life, the value
2143 * found in the field of measure of staleness should be doubled
2144 * to give ample time to retransmit the new cookie and thus
2145 * yield a higher probability of success on the reattempt.
2147 stale
= ntohl(*(suseconds_t
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2148 stale
= (stale
* 2) / 1000;
2150 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2151 bht
.param_hdr
.length
= htons(sizeof(bht
));
2152 bht
.lifespan_increment
= htonl(stale
);
2154 /* Build that new INIT chunk. */
2155 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2156 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2160 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2162 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2163 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2165 /* Stop pending T3-rtx and heartbeat timers */
2166 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2167 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2169 /* Delete non-primary peer ip addresses since we are transitioning
2170 * back to the COOKIE-WAIT state
2172 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2174 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2177 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
,
2178 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2180 /* Cast away the const modifier, as we want to just
2181 * rerun it through as a sideffect.
2183 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2185 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2186 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2187 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2188 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2189 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2190 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2192 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2194 return SCTP_DISPOSITION_CONSUME
;
2197 return SCTP_DISPOSITION_NOMEM
;
2204 * After checking the Verification Tag, the receiving endpoint shall
2205 * remove the association from its record, and shall report the
2206 * termination to its upper layer.
2208 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2209 * B) Rules for packet carrying ABORT:
2211 * - The endpoint shall always fill in the Verification Tag field of the
2212 * outbound packet with the destination endpoint's tag value if it
2215 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2216 * MUST follow the procedure described in Section 8.4.
2218 * - The receiver MUST accept the packet if the Verification Tag
2219 * matches either its own tag, OR the tag of its peer. Otherwise, the
2220 * receiver MUST silently discard the packet and take no further
2224 * (endpoint, asoc, chunk)
2227 * (asoc, reply_msg, msg_up, timers, counters)
2229 * The return value is the disposition of the chunk.
2231 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2232 const struct sctp_association
*asoc
,
2233 const sctp_subtype_t type
,
2235 sctp_cmd_seq_t
*commands
)
2237 struct sctp_chunk
*chunk
= arg
;
2239 __u16 error
= SCTP_ERROR_NO_ERROR
;
2241 if (!sctp_vtag_verify_either(chunk
, asoc
))
2242 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2244 /* Make sure that the ABORT chunk has a valid length.
2245 * Since this is an ABORT chunk, we have to discard it
2246 * because of the following text:
2247 * RFC 2960, Section 3.3.7
2248 * If an endpoint receives an ABORT with a format error or for an
2249 * association that doesn't exist, it MUST silently discard it.
2250 * Becasue the length is "invalid", we can't really discard just
2251 * as we do not know its true length. So, to be safe, discard the
2254 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2255 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2257 /* See if we have an error cause code in the chunk. */
2258 len
= ntohs(chunk
->chunk_hdr
->length
);
2259 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2260 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2262 /* ASSOC_FAILED will DELETE_TCB. */
2263 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_U32(error
));
2264 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2265 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2267 return SCTP_DISPOSITION_ABORT
;
2271 * Process an ABORT. (COOKIE-WAIT state)
2273 * See sctp_sf_do_9_1_abort() above.
2275 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2276 const struct sctp_association
*asoc
,
2277 const sctp_subtype_t type
,
2279 sctp_cmd_seq_t
*commands
)
2281 struct sctp_chunk
*chunk
= arg
;
2283 __u16 error
= SCTP_ERROR_NO_ERROR
;
2285 if (!sctp_vtag_verify_either(chunk
, asoc
))
2286 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2288 /* Make sure that the ABORT chunk has a valid length.
2289 * Since this is an ABORT chunk, we have to discard it
2290 * because of the following text:
2291 * RFC 2960, Section 3.3.7
2292 * If an endpoint receives an ABORT with a format error or for an
2293 * association that doesn't exist, it MUST silently discard it.
2294 * Becasue the length is "invalid", we can't really discard just
2295 * as we do not know its true length. So, to be safe, discard the
2298 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2299 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2301 /* See if we have an error cause code in the chunk. */
2302 len
= ntohs(chunk
->chunk_hdr
->length
);
2303 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2304 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2306 return sctp_stop_t1_and_abort(commands
, error
, asoc
, chunk
->transport
);
2310 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2312 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2313 const struct sctp_association
*asoc
,
2314 const sctp_subtype_t type
,
2316 sctp_cmd_seq_t
*commands
)
2318 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
, asoc
,
2319 (struct sctp_transport
*)arg
);
2323 * Process an ABORT. (COOKIE-ECHOED state)
2325 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2326 const struct sctp_association
*asoc
,
2327 const sctp_subtype_t type
,
2329 sctp_cmd_seq_t
*commands
)
2331 /* There is a single T1 timer, so we should be able to use
2332 * common function with the COOKIE-WAIT state.
2334 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2338 * Stop T1 timer and abort association with "INIT failed".
2340 * This is common code called by several sctp_sf_*_abort() functions above.
2342 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2344 const struct sctp_association
*asoc
,
2345 struct sctp_transport
*transport
)
2347 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2348 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2349 SCTP_STATE(SCTP_STATE_CLOSED
));
2350 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2351 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2352 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2353 /* CMD_INIT_FAILED will DELETE_TCB. */
2354 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2356 return SCTP_DISPOSITION_ABORT
;
2360 * sctp_sf_do_9_2_shut
2363 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2364 * - enter the SHUTDOWN-RECEIVED state,
2366 * - stop accepting new data from its SCTP user
2368 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2369 * that all its outstanding DATA chunks have been received by the
2372 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2373 * send a SHUTDOWN in response to a ULP request. And should discard
2374 * subsequent SHUTDOWN chunks.
2376 * If there are still outstanding DATA chunks left, the SHUTDOWN
2377 * receiver shall continue to follow normal data transmission
2378 * procedures defined in Section 6 until all outstanding DATA chunks
2379 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2380 * new data from its SCTP user.
2382 * Verification Tag: 8.5 Verification Tag [Normal verification]
2385 * (endpoint, asoc, chunk)
2388 * (asoc, reply_msg, msg_up, timers, counters)
2390 * The return value is the disposition of the chunk.
2392 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2393 const struct sctp_association
*asoc
,
2394 const sctp_subtype_t type
,
2396 sctp_cmd_seq_t
*commands
)
2398 struct sctp_chunk
*chunk
= arg
;
2399 sctp_shutdownhdr_t
*sdh
;
2400 sctp_disposition_t disposition
;
2401 struct sctp_ulpevent
*ev
;
2403 if (!sctp_vtag_verify(chunk
, asoc
))
2404 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2406 /* Make sure that the SHUTDOWN chunk has a valid length. */
2407 if (!sctp_chunk_length_valid(chunk
,
2408 sizeof(struct sctp_shutdown_chunk_t
)))
2409 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2412 /* Convert the elaborate header. */
2413 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2414 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2415 chunk
->subh
.shutdown_hdr
= sdh
;
2417 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2418 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2419 * inform the application that it should cease sending data.
2421 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2423 disposition
= SCTP_DISPOSITION_NOMEM
;
2426 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2428 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2429 * - enter the SHUTDOWN-RECEIVED state,
2430 * - stop accepting new data from its SCTP user
2432 * [This is implicit in the new state.]
2434 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2435 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2436 disposition
= SCTP_DISPOSITION_CONSUME
;
2438 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2439 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2443 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2446 /* - verify, by checking the Cumulative TSN Ack field of the
2447 * chunk, that all its outstanding DATA chunks have been
2448 * received by the SHUTDOWN sender.
2450 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2451 SCTP_U32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2458 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2459 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2460 * transport addresses (either in the IP addresses or in the INIT chunk)
2461 * that belong to this association, it should discard the INIT chunk and
2462 * retransmit the SHUTDOWN ACK chunk.
2464 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2465 const struct sctp_association
*asoc
,
2466 const sctp_subtype_t type
,
2468 sctp_cmd_seq_t
*commands
)
2470 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2471 struct sctp_chunk
*reply
;
2473 /* Since we are not going to really process this INIT, there
2474 * is no point in verifying chunk boundries. Just generate
2477 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2481 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2482 * the T2-SHUTDOWN timer.
2484 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2486 /* and restart the T2-shutdown timer. */
2487 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2488 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2490 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2492 return SCTP_DISPOSITION_CONSUME
;
2494 return SCTP_DISPOSITION_NOMEM
;
2498 * sctp_sf_do_ecn_cwr
2500 * Section: Appendix A: Explicit Congestion Notification
2504 * RFC 2481 details a specific bit for a sender to send in the header of
2505 * its next outbound TCP segment to indicate to its peer that it has
2506 * reduced its congestion window. This is termed the CWR bit. For
2507 * SCTP the same indication is made by including the CWR chunk.
2508 * This chunk contains one data element, i.e. the TSN number that
2509 * was sent in the ECNE chunk. This element represents the lowest
2510 * TSN number in the datagram that was originally marked with the
2513 * Verification Tag: 8.5 Verification Tag [Normal verification]
2515 * (endpoint, asoc, chunk)
2518 * (asoc, reply_msg, msg_up, timers, counters)
2520 * The return value is the disposition of the chunk.
2522 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2523 const struct sctp_association
*asoc
,
2524 const sctp_subtype_t type
,
2526 sctp_cmd_seq_t
*commands
)
2529 struct sctp_chunk
*chunk
= arg
;
2531 if (!sctp_vtag_verify(chunk
, asoc
))
2532 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2534 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2535 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2538 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2539 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2541 cwr
->lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2543 /* Does this CWR ack the last sent congestion notification? */
2544 if (TSN_lte(asoc
->last_ecne_tsn
, cwr
->lowest_tsn
)) {
2545 /* Stop sending ECNE. */
2546 sctp_add_cmd_sf(commands
,
2548 SCTP_U32(cwr
->lowest_tsn
));
2550 return SCTP_DISPOSITION_CONSUME
;
2556 * Section: Appendix A: Explicit Congestion Notification
2560 * RFC 2481 details a specific bit for a receiver to send back in its
2561 * TCP acknowledgements to notify the sender of the Congestion
2562 * Experienced (CE) bit having arrived from the network. For SCTP this
2563 * same indication is made by including the ECNE chunk. This chunk
2564 * contains one data element, i.e. the lowest TSN associated with the IP
2565 * datagram marked with the CE bit.....
2567 * Verification Tag: 8.5 Verification Tag [Normal verification]
2569 * (endpoint, asoc, chunk)
2572 * (asoc, reply_msg, msg_up, timers, counters)
2574 * The return value is the disposition of the chunk.
2576 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2577 const struct sctp_association
*asoc
,
2578 const sctp_subtype_t type
,
2580 sctp_cmd_seq_t
*commands
)
2582 sctp_ecnehdr_t
*ecne
;
2583 struct sctp_chunk
*chunk
= arg
;
2585 if (!sctp_vtag_verify(chunk
, asoc
))
2586 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2588 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2589 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2592 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2593 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2595 /* If this is a newer ECNE than the last CWR packet we sent out */
2596 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2597 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2599 return SCTP_DISPOSITION_CONSUME
;
2603 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2605 * The SCTP endpoint MUST always acknowledge the reception of each valid
2608 * The guidelines on delayed acknowledgement algorithm specified in
2609 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2610 * acknowledgement SHOULD be generated for at least every second packet
2611 * (not every second DATA chunk) received, and SHOULD be generated within
2612 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2613 * situations it may be beneficial for an SCTP transmitter to be more
2614 * conservative than the algorithms detailed in this document allow.
2615 * However, an SCTP transmitter MUST NOT be more aggressive than the
2616 * following algorithms allow.
2618 * A SCTP receiver MUST NOT generate more than one SACK for every
2619 * incoming packet, other than to update the offered window as the
2620 * receiving application consumes new data.
2622 * Verification Tag: 8.5 Verification Tag [Normal verification]
2625 * (endpoint, asoc, chunk)
2628 * (asoc, reply_msg, msg_up, timers, counters)
2630 * The return value is the disposition of the chunk.
2632 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2633 const struct sctp_association
*asoc
,
2634 const sctp_subtype_t type
,
2636 sctp_cmd_seq_t
*commands
)
2638 struct sctp_chunk
*chunk
= arg
;
2641 if (!sctp_vtag_verify(chunk
, asoc
)) {
2642 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2644 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2647 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2648 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2651 error
= sctp_eat_data(asoc
, chunk
, commands
);
2653 case SCTP_IERROR_NO_ERROR
:
2655 case SCTP_IERROR_HIGH_TSN
:
2656 case SCTP_IERROR_BAD_STREAM
:
2657 goto discard_noforce
;
2658 case SCTP_IERROR_DUP_TSN
:
2659 case SCTP_IERROR_IGNORE_TSN
:
2661 case SCTP_IERROR_NO_DATA
:
2667 if (asoc
->autoclose
) {
2668 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2669 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2672 /* If this is the last chunk in a packet, we need to count it
2673 * toward sack generation. Note that we need to SACK every
2674 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2675 * THEM. We elect to NOT generate SACK's if the chunk fails
2676 * the verification tag test.
2678 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2680 * The SCTP endpoint MUST always acknowledge the reception of
2681 * each valid DATA chunk.
2683 * The guidelines on delayed acknowledgement algorithm
2684 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2685 * Specifically, an acknowledgement SHOULD be generated for at
2686 * least every second packet (not every second DATA chunk)
2687 * received, and SHOULD be generated within 200 ms of the
2688 * arrival of any unacknowledged DATA chunk. In some
2689 * situations it may be beneficial for an SCTP transmitter to
2690 * be more conservative than the algorithms detailed in this
2691 * document allow. However, an SCTP transmitter MUST NOT be
2692 * more aggressive than the following algorithms allow.
2694 if (chunk
->end_of_packet
)
2695 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2697 return SCTP_DISPOSITION_CONSUME
;
2700 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2702 * When a packet arrives with duplicate DATA chunk(s) and with
2703 * no new DATA chunk(s), the endpoint MUST immediately send a
2704 * SACK with no delay. If a packet arrives with duplicate
2705 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2706 * MAY immediately send a SACK. Normally receipt of duplicate
2707 * DATA chunks will occur when the original SACK chunk was lost
2708 * and the peer's RTO has expired. The duplicate TSN number(s)
2709 * SHOULD be reported in the SACK as duplicate.
2711 /* In our case, we split the MAY SACK advice up whether or not
2712 * the last chunk is a duplicate.'
2714 if (chunk
->end_of_packet
)
2715 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2716 return SCTP_DISPOSITION_DISCARD
;
2719 if (chunk
->end_of_packet
)
2720 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2722 return SCTP_DISPOSITION_DISCARD
;
2724 return SCTP_DISPOSITION_CONSUME
;
2729 * sctp_sf_eat_data_fast_4_4
2732 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2733 * DATA chunks without delay.
2735 * Verification Tag: 8.5 Verification Tag [Normal verification]
2737 * (endpoint, asoc, chunk)
2740 * (asoc, reply_msg, msg_up, timers, counters)
2742 * The return value is the disposition of the chunk.
2744 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2745 const struct sctp_association
*asoc
,
2746 const sctp_subtype_t type
,
2748 sctp_cmd_seq_t
*commands
)
2750 struct sctp_chunk
*chunk
= arg
;
2753 if (!sctp_vtag_verify(chunk
, asoc
)) {
2754 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2756 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2759 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2760 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2763 error
= sctp_eat_data(asoc
, chunk
, commands
);
2765 case SCTP_IERROR_NO_ERROR
:
2766 case SCTP_IERROR_HIGH_TSN
:
2767 case SCTP_IERROR_DUP_TSN
:
2768 case SCTP_IERROR_IGNORE_TSN
:
2769 case SCTP_IERROR_BAD_STREAM
:
2771 case SCTP_IERROR_NO_DATA
:
2777 /* Go a head and force a SACK, since we are shutting down. */
2779 /* Implementor's Guide.
2781 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2782 * respond to each received packet containing one or more DATA chunk(s)
2783 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2785 if (chunk
->end_of_packet
) {
2786 /* We must delay the chunk creation since the cumulative
2787 * TSN has not been updated yet.
2789 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
2790 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2791 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2792 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2796 return SCTP_DISPOSITION_CONSUME
;
2800 * Section: 6.2 Processing a Received SACK
2801 * D) Any time a SACK arrives, the endpoint performs the following:
2803 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2804 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2805 * increasing, a SACK whose Cumulative TSN Ack is less than the
2806 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2808 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2809 * of bytes still outstanding after processing the Cumulative TSN Ack
2810 * and the Gap Ack Blocks.
2812 * iii) If the SACK is missing a TSN that was previously
2813 * acknowledged via a Gap Ack Block (e.g., the data receiver
2814 * reneged on the data), then mark the corresponding DATA chunk
2815 * as available for retransmit: Mark it as missing for fast
2816 * retransmit as described in Section 7.2.4 and if no retransmit
2817 * timer is running for the destination address to which the DATA
2818 * chunk was originally transmitted, then T3-rtx is started for
2819 * that destination address.
2821 * Verification Tag: 8.5 Verification Tag [Normal verification]
2824 * (endpoint, asoc, chunk)
2827 * (asoc, reply_msg, msg_up, timers, counters)
2829 * The return value is the disposition of the chunk.
2831 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
2832 const struct sctp_association
*asoc
,
2833 const sctp_subtype_t type
,
2835 sctp_cmd_seq_t
*commands
)
2837 struct sctp_chunk
*chunk
= arg
;
2838 sctp_sackhdr_t
*sackh
;
2841 if (!sctp_vtag_verify(chunk
, asoc
))
2842 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2844 /* Make sure that the SACK chunk has a valid length. */
2845 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
2846 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2849 /* Pull the SACK chunk from the data buffer */
2850 sackh
= sctp_sm_pull_sack(chunk
);
2851 /* Was this a bogus SACK? */
2853 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2854 chunk
->subh
.sack_hdr
= sackh
;
2855 ctsn
= ntohl(sackh
->cum_tsn_ack
);
2857 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2858 * Ack Point, then drop the SACK. Since Cumulative TSN
2859 * Ack is monotonically increasing, a SACK whose
2860 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2861 * Point indicates an out-of-order SACK.
2863 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2864 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2865 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2866 return SCTP_DISPOSITION_DISCARD
;
2869 /* Return this SACK for further processing. */
2870 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
2872 /* Note: We do the rest of the work on the PROCESS_SACK
2875 return SCTP_DISPOSITION_CONSUME
;
2879 * Generate an ABORT in response to a packet.
2881 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
2883 * 8) The receiver should respond to the sender of the OOTB packet with
2884 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2885 * MUST fill in the Verification Tag field of the outbound packet
2886 * with the value found in the Verification Tag field of the OOTB
2887 * packet and set the T-bit in the Chunk Flags to indicate that the
2888 * Verification Tag is reflected. After sending this ABORT, the
2889 * receiver of the OOTB packet shall discard the OOTB packet and take
2890 * no further action.
2894 * The return value is the disposition of the chunk.
2896 sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
2897 const struct sctp_association
*asoc
,
2898 const sctp_subtype_t type
,
2900 sctp_cmd_seq_t
*commands
)
2902 struct sctp_packet
*packet
= NULL
;
2903 struct sctp_chunk
*chunk
= arg
;
2904 struct sctp_chunk
*abort
;
2906 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
2909 /* Make an ABORT. The T bit will be set if the asoc
2912 abort
= sctp_make_abort(asoc
, chunk
, 0);
2914 sctp_ootb_pkt_free(packet
);
2915 return SCTP_DISPOSITION_NOMEM
;
2918 /* Reflect vtag if T-Bit is set */
2919 if (sctp_test_T_bit(abort
))
2920 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
2922 /* Set the skb to the belonging sock for accounting. */
2923 abort
->skb
->sk
= ep
->base
.sk
;
2925 sctp_packet_append_chunk(packet
, abort
);
2927 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
2928 SCTP_PACKET(packet
));
2930 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
2932 return SCTP_DISPOSITION_CONSUME
;
2935 return SCTP_DISPOSITION_NOMEM
;
2939 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2940 * event as ULP notification for each cause included in the chunk.
2942 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2944 * The return value is the disposition of the chunk.
2946 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
2947 const struct sctp_association
*asoc
,
2948 const sctp_subtype_t type
,
2950 sctp_cmd_seq_t
*commands
)
2952 struct sctp_chunk
*chunk
= arg
;
2953 struct sctp_ulpevent
*ev
;
2955 if (!sctp_vtag_verify(chunk
, asoc
))
2956 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2958 /* Make sure that the ERROR chunk has a valid length. */
2959 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2960 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2963 while (chunk
->chunk_end
> chunk
->skb
->data
) {
2964 ev
= sctp_ulpevent_make_remote_error(asoc
, chunk
, 0,
2969 if (!sctp_add_cmd(commands
, SCTP_CMD_EVENT_ULP
,
2970 SCTP_ULPEVENT(ev
))) {
2971 sctp_ulpevent_free(ev
);
2975 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
2978 return SCTP_DISPOSITION_CONSUME
;
2981 return SCTP_DISPOSITION_NOMEM
;
2985 * Process an inbound SHUTDOWN ACK.
2988 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2989 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2990 * peer, and remove all record of the association.
2992 * The return value is the disposition.
2994 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
2995 const struct sctp_association
*asoc
,
2996 const sctp_subtype_t type
,
2998 sctp_cmd_seq_t
*commands
)
3000 struct sctp_chunk
*chunk
= arg
;
3001 struct sctp_chunk
*reply
;
3002 struct sctp_ulpevent
*ev
;
3004 if (!sctp_vtag_verify(chunk
, asoc
))
3005 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3007 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3008 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3009 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3012 /* 10.2 H) SHUTDOWN COMPLETE notification
3014 * When SCTP completes the shutdown procedures (section 9.2) this
3015 * notification is passed to the upper layer.
3017 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3018 0, 0, 0, GFP_ATOMIC
);
3022 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3024 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3025 * stop the T2-shutdown timer,
3027 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3028 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3030 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3031 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3033 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3034 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3038 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3039 SCTP_STATE(SCTP_STATE_CLOSED
));
3040 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3041 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3042 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3044 /* ...and remove all record of the association. */
3045 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3046 return SCTP_DISPOSITION_DELETE_TCB
;
3049 return SCTP_DISPOSITION_NOMEM
;
3053 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3055 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3056 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3057 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3058 * packet must fill in the Verification Tag field of the outbound
3059 * packet with the Verification Tag received in the SHUTDOWN ACK and
3060 * set the T-bit in the Chunk Flags to indicate that the Verification
3063 * 8) The receiver should respond to the sender of the OOTB packet with
3064 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3065 * MUST fill in the Verification Tag field of the outbound packet
3066 * with the value found in the Verification Tag field of the OOTB
3067 * packet and set the T-bit in the Chunk Flags to indicate that the
3068 * Verification Tag is reflected. After sending this ABORT, the
3069 * receiver of the OOTB packet shall discard the OOTB packet and take
3070 * no further action.
3072 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3073 const struct sctp_association
*asoc
,
3074 const sctp_subtype_t type
,
3076 sctp_cmd_seq_t
*commands
)
3078 struct sctp_chunk
*chunk
= arg
;
3079 struct sk_buff
*skb
= chunk
->skb
;
3080 sctp_chunkhdr_t
*ch
;
3082 int ootb_shut_ack
= 0;
3084 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3086 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3088 /* Break out if chunk length is less then minimal. */
3089 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3092 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3093 if (ch_end
> skb
->tail
)
3096 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3099 /* RFC 2960, Section 3.3.7
3100 * Moreover, under any circumstances, an endpoint that
3101 * receives an ABORT MUST NOT respond to that ABORT by
3102 * sending an ABORT of its own.
3104 if (SCTP_CID_ABORT
== ch
->type
)
3105 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3107 ch
= (sctp_chunkhdr_t
*) ch_end
;
3108 } while (ch_end
< skb
->tail
);
3111 sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3113 sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3115 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3119 * Handle an "Out of the blue" SHUTDOWN ACK.
3121 * Section: 8.4 5, sctpimpguide 2.41.
3123 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3124 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3125 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3126 * packet must fill in the Verification Tag field of the outbound
3127 * packet with the Verification Tag received in the SHUTDOWN ACK and
3128 * set the T-bit in the Chunk Flags to indicate that the Verification
3132 * (endpoint, asoc, type, arg, commands)
3135 * (sctp_disposition_t)
3137 * The return value is the disposition of the chunk.
3139 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3140 const struct sctp_association
*asoc
,
3141 const sctp_subtype_t type
,
3143 sctp_cmd_seq_t
*commands
)
3145 struct sctp_packet
*packet
= NULL
;
3146 struct sctp_chunk
*chunk
= arg
;
3147 struct sctp_chunk
*shut
;
3149 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3152 /* Make an SHUTDOWN_COMPLETE.
3153 * The T bit will be set if the asoc is NULL.
3155 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3157 sctp_ootb_pkt_free(packet
);
3158 return SCTP_DISPOSITION_NOMEM
;
3161 /* Reflect vtag if T-Bit is set */
3162 if (sctp_test_T_bit(shut
))
3163 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3165 /* Set the skb to the belonging sock for accounting. */
3166 shut
->skb
->sk
= ep
->base
.sk
;
3168 sctp_packet_append_chunk(packet
, shut
);
3170 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3171 SCTP_PACKET(packet
));
3173 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3175 /* If the chunk length is invalid, we don't want to process
3176 * the reset of the packet.
3178 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3179 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3181 return SCTP_DISPOSITION_CONSUME
;
3184 return SCTP_DISPOSITION_NOMEM
;
3188 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3190 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3191 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3192 * procedures in section 8.4 SHOULD be followed, in other words it
3193 * should be treated as an Out Of The Blue packet.
3194 * [This means that we do NOT check the Verification Tag on these
3198 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3199 const struct sctp_association
*asoc
,
3200 const sctp_subtype_t type
,
3202 sctp_cmd_seq_t
*commands
)
3204 /* Although we do have an association in this case, it corresponds
3205 * to a restarted association. So the packet is treated as an OOTB
3206 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3207 * called with a NULL association.
3209 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3212 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3213 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3214 const struct sctp_association
*asoc
,
3215 const sctp_subtype_t type
, void *arg
,
3216 sctp_cmd_seq_t
*commands
)
3218 struct sctp_chunk
*chunk
= arg
;
3219 struct sctp_chunk
*asconf_ack
= NULL
;
3220 sctp_addiphdr_t
*hdr
;
3223 if (!sctp_vtag_verify(chunk
, asoc
)) {
3224 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3226 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3229 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3230 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3231 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3234 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3235 serial
= ntohl(hdr
->serial
);
3237 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3238 * the endpoint stored in a new association variable
3239 * 'Peer-Serial-Number'.
3241 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3242 /* ADDIP 4.2 C2) If the value found in the serial number is
3243 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3246 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3249 return SCTP_DISPOSITION_NOMEM
;
3250 } else if (serial
== asoc
->peer
.addip_serial
) {
3251 /* ADDIP 4.2 C3) If the value found in the serial number is
3252 * equal to the value stored in the 'Peer-Serial-Number'
3253 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3254 * to save the last ASCONF-ACK for some predetermined period of
3255 * time and instead of re-processing the ASCONF (with the same
3256 * serial number) it may just re-transmit the ASCONF-ACK.
3258 if (asoc
->addip_last_asconf_ack
)
3259 asconf_ack
= asoc
->addip_last_asconf_ack
;
3261 return SCTP_DISPOSITION_DISCARD
;
3263 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3264 * it must be either a stale packet or from an attacker.
3266 return SCTP_DISPOSITION_DISCARD
;
3269 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3270 * back to the source address contained in the IP header of the ASCONF
3271 * being responded to.
3273 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3275 return SCTP_DISPOSITION_CONSUME
;
3279 * ADDIP Section 4.3 General rules for address manipulation
3280 * When building TLV parameters for the ASCONF Chunk that will add or
3281 * delete IP addresses the D0 to D13 rules should be applied:
3283 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3284 const struct sctp_association
*asoc
,
3285 const sctp_subtype_t type
, void *arg
,
3286 sctp_cmd_seq_t
*commands
)
3288 struct sctp_chunk
*asconf_ack
= arg
;
3289 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3290 struct sctp_chunk
*abort
;
3291 sctp_addiphdr_t
*addip_hdr
;
3292 __u32 sent_serial
, rcvd_serial
;
3294 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3295 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3297 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3300 /* Make sure that the ADDIP chunk has a valid length. */
3301 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3302 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3305 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3306 rcvd_serial
= ntohl(addip_hdr
->serial
);
3309 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3310 sent_serial
= ntohl(addip_hdr
->serial
);
3312 sent_serial
= asoc
->addip_serial
- 1;
3315 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3316 * equal to the next serial number to be used but no ASCONF chunk is
3317 * outstanding the endpoint MUST ABORT the association. Note that a
3318 * sequence number is greater than if it is no more than 2^^31-1
3319 * larger than the current sequence number (using serial arithmetic).
3321 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3322 !(asoc
->addip_last_asconf
)) {
3323 abort
= sctp_make_abort(asoc
, asconf_ack
,
3324 sizeof(sctp_errhdr_t
));
3326 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, NULL
, 0);
3327 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3330 /* We are going to ABORT, so we might as well stop
3331 * processing the rest of the chunks in the packet.
3333 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3334 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3335 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3336 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3337 SCTP_U32(SCTP_ERROR_ASCONF_ACK
));
3338 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3339 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3340 return SCTP_DISPOSITION_ABORT
;
3343 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3344 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3345 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3347 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3349 return SCTP_DISPOSITION_CONSUME
;
3351 abort
= sctp_make_abort(asoc
, asconf_ack
,
3352 sizeof(sctp_errhdr_t
));
3354 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, NULL
, 0);
3355 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3358 /* We are going to ABORT, so we might as well stop
3359 * processing the rest of the chunks in the packet.
3361 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3362 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3363 SCTP_U32(SCTP_ERROR_ASCONF_ACK
));
3364 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3365 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3366 return SCTP_DISPOSITION_ABORT
;
3369 return SCTP_DISPOSITION_DISCARD
;
3373 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3375 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3376 * its cumulative TSN point to the value carried in the FORWARD TSN
3377 * chunk, and then MUST further advance its cumulative TSN point locally
3379 * After the above processing, the data receiver MUST stop reporting any
3380 * missing TSNs earlier than or equal to the new cumulative TSN point.
3382 * Verification Tag: 8.5 Verification Tag [Normal verification]
3384 * The return value is the disposition of the chunk.
3386 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3387 const struct sctp_association
*asoc
,
3388 const sctp_subtype_t type
,
3390 sctp_cmd_seq_t
*commands
)
3392 struct sctp_chunk
*chunk
= arg
;
3393 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3397 if (!sctp_vtag_verify(chunk
, asoc
)) {
3398 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3400 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3403 /* Make sure that the FORWARD_TSN chunk has valid length. */
3404 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3405 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3408 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3409 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3410 len
= ntohs(chunk
->chunk_hdr
->length
);
3411 len
-= sizeof(struct sctp_chunkhdr
);
3412 skb_pull(chunk
->skb
, len
);
3414 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3415 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__
, tsn
);
3417 /* The TSN is too high--silently discard the chunk and count on it
3418 * getting retransmitted later.
3420 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3421 goto discard_noforce
;
3423 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3424 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3425 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3428 /* Count this as receiving DATA. */
3429 if (asoc
->autoclose
) {
3430 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3431 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3434 /* FIXME: For now send a SACK, but DATA processing may
3437 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3439 return SCTP_DISPOSITION_CONSUME
;
3442 return SCTP_DISPOSITION_DISCARD
;
3445 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3446 const struct sctp_endpoint
*ep
,
3447 const struct sctp_association
*asoc
,
3448 const sctp_subtype_t type
,
3450 sctp_cmd_seq_t
*commands
)
3452 struct sctp_chunk
*chunk
= arg
;
3453 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3457 if (!sctp_vtag_verify(chunk
, asoc
)) {
3458 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3460 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3463 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3464 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3465 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3468 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3469 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3470 len
= ntohs(chunk
->chunk_hdr
->length
);
3471 len
-= sizeof(struct sctp_chunkhdr
);
3472 skb_pull(chunk
->skb
, len
);
3474 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3475 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__
, tsn
);
3477 /* The TSN is too high--silently discard the chunk and count on it
3478 * getting retransmitted later.
3480 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3483 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3484 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3485 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3488 /* Go a head and force a SACK, since we are shutting down. */
3490 /* Implementor's Guide.
3492 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3493 * respond to each received packet containing one or more DATA chunk(s)
3494 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3496 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3497 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3498 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3499 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3501 return SCTP_DISPOSITION_CONSUME
;
3505 * Process an unknown chunk.
3507 * Section: 3.2. Also, 2.1 in the implementor's guide.
3509 * Chunk Types are encoded such that the highest-order two bits specify
3510 * the action that must be taken if the processing endpoint does not
3511 * recognize the Chunk Type.
3513 * 00 - Stop processing this SCTP packet and discard it, do not process
3514 * any further chunks within it.
3516 * 01 - Stop processing this SCTP packet and discard it, do not process
3517 * any further chunks within it, and report the unrecognized
3518 * chunk in an 'Unrecognized Chunk Type'.
3520 * 10 - Skip this chunk and continue processing.
3522 * 11 - Skip this chunk and continue processing, but report in an ERROR
3523 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3525 * The return value is the disposition of the chunk.
3527 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
3528 const struct sctp_association
*asoc
,
3529 const sctp_subtype_t type
,
3531 sctp_cmd_seq_t
*commands
)
3533 struct sctp_chunk
*unk_chunk
= arg
;
3534 struct sctp_chunk
*err_chunk
;
3535 sctp_chunkhdr_t
*hdr
;
3537 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
3539 if (!sctp_vtag_verify(unk_chunk
, asoc
))
3540 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3542 /* Make sure that the chunk has a valid length.
3543 * Since we don't know the chunk type, we use a general
3544 * chunkhdr structure to make a comparison.
3546 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
3547 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3550 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
3551 case SCTP_CID_ACTION_DISCARD
:
3552 /* Discard the packet. */
3553 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3555 case SCTP_CID_ACTION_DISCARD_ERR
:
3556 /* Discard the packet. */
3557 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3559 /* Generate an ERROR chunk as response. */
3560 hdr
= unk_chunk
->chunk_hdr
;
3561 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3562 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3563 WORD_ROUND(ntohs(hdr
->length
)));
3565 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3566 SCTP_CHUNK(err_chunk
));
3568 return SCTP_DISPOSITION_CONSUME
;
3570 case SCTP_CID_ACTION_SKIP
:
3571 /* Skip the chunk. */
3572 return SCTP_DISPOSITION_DISCARD
;
3574 case SCTP_CID_ACTION_SKIP_ERR
:
3575 /* Generate an ERROR chunk as response. */
3576 hdr
= unk_chunk
->chunk_hdr
;
3577 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3578 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3579 WORD_ROUND(ntohs(hdr
->length
)));
3581 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3582 SCTP_CHUNK(err_chunk
));
3584 /* Skip the chunk. */
3585 return SCTP_DISPOSITION_CONSUME
;
3591 return SCTP_DISPOSITION_DISCARD
;
3595 * Discard the chunk.
3597 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3598 * [Too numerous to mention...]
3599 * Verification Tag: No verification needed.
3601 * (endpoint, asoc, chunk)
3604 * (asoc, reply_msg, msg_up, timers, counters)
3606 * The return value is the disposition of the chunk.
3608 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
3609 const struct sctp_association
*asoc
,
3610 const sctp_subtype_t type
,
3612 sctp_cmd_seq_t
*commands
)
3614 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
3615 return SCTP_DISPOSITION_DISCARD
;
3619 * Discard the whole packet.
3623 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3624 * silently discard the OOTB packet and take no further action.
3626 * Verification Tag: No verification necessary
3629 * (endpoint, asoc, chunk)
3632 * (asoc, reply_msg, msg_up, timers, counters)
3634 * The return value is the disposition of the chunk.
3636 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
3637 const struct sctp_association
*asoc
,
3638 const sctp_subtype_t type
,
3640 sctp_cmd_seq_t
*commands
)
3642 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3644 return SCTP_DISPOSITION_CONSUME
;
3649 * The other end is violating protocol.
3651 * Section: Not specified
3652 * Verification Tag: Not specified
3654 * (endpoint, asoc, chunk)
3657 * (asoc, reply_msg, msg_up, timers, counters)
3659 * We simply tag the chunk as a violation. The state machine will log
3660 * the violation and continue.
3662 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
3663 const struct sctp_association
*asoc
,
3664 const sctp_subtype_t type
,
3666 sctp_cmd_seq_t
*commands
)
3668 return SCTP_DISPOSITION_VIOLATION
;
3673 * Handle a protocol violation when the chunk length is invalid.
3674 * "Invalid" length is identified as smaller then the minimal length a
3675 * given chunk can be. For example, a SACK chunk has invalid length
3676 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3678 * We inform the other end by sending an ABORT with a Protocol Violation
3681 * Section: Not specified
3682 * Verification Tag: Nothing to do
3684 * (endpoint, asoc, chunk)
3687 * (reply_msg, msg_up, counters)
3689 * Generate an ABORT chunk and terminate the association.
3691 static sctp_disposition_t
sctp_sf_violation_chunklen(
3692 const struct sctp_endpoint
*ep
,
3693 const struct sctp_association
*asoc
,
3694 const sctp_subtype_t type
,
3696 sctp_cmd_seq_t
*commands
)
3698 struct sctp_chunk
*chunk
= arg
;
3699 struct sctp_chunk
*abort
= NULL
;
3700 char err_str
[]="The following chunk had invalid length:";
3702 /* Make the abort chunk. */
3703 abort
= sctp_make_abort_violation(asoc
, chunk
, err_str
,
3708 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
3709 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3711 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
3712 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3713 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
3714 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
3715 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION
));
3717 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3718 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION
));
3719 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3722 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3724 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3726 return SCTP_DISPOSITION_ABORT
;
3729 return SCTP_DISPOSITION_NOMEM
;
3732 /***************************************************************************
3733 * These are the state functions for handling primitive (Section 10) events.
3734 ***************************************************************************/
3736 * sctp_sf_do_prm_asoc
3738 * Section: 10.1 ULP-to-SCTP
3741 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3742 * outbound stream count)
3743 * -> association id [,destination transport addr list] [,outbound stream
3746 * This primitive allows the upper layer to initiate an association to a
3747 * specific peer endpoint.
3749 * The peer endpoint shall be specified by one of the transport addresses
3750 * which defines the endpoint (see Section 1.4). If the local SCTP
3751 * instance has not been initialized, the ASSOCIATE is considered an
3753 * [This is not relevant for the kernel implementation since we do all
3754 * initialization at boot time. It we hadn't initialized we wouldn't
3755 * get anywhere near this code.]
3757 * An association id, which is a local handle to the SCTP association,
3758 * will be returned on successful establishment of the association. If
3759 * SCTP is not able to open an SCTP association with the peer endpoint,
3760 * an error is returned.
3761 * [In the kernel implementation, the struct sctp_association needs to
3762 * be created BEFORE causing this primitive to run.]
3764 * Other association parameters may be returned, including the
3765 * complete destination transport addresses of the peer as well as the
3766 * outbound stream count of the local endpoint. One of the transport
3767 * address from the returned destination addresses will be selected by
3768 * the local endpoint as default primary path for sending SCTP packets
3769 * to this peer. The returned "destination transport addr list" can
3770 * be used by the ULP to change the default primary path or to force
3771 * sending a packet to a specific transport address. [All of this
3772 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3775 * Mandatory attributes:
3777 * o local SCTP instance name - obtained from the INITIALIZE operation.
3778 * [This is the argument asoc.]
3779 * o destination transport addr - specified as one of the transport
3780 * addresses of the peer endpoint with which the association is to be
3782 * [This is asoc->peer.active_path.]
3783 * o outbound stream count - the number of outbound streams the ULP
3784 * would like to open towards this peer endpoint.
3785 * [BUG: This is not currently implemented.]
3786 * Optional attributes:
3790 * The return value is a disposition.
3792 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
3793 const struct sctp_association
*asoc
,
3794 const sctp_subtype_t type
,
3796 sctp_cmd_seq_t
*commands
)
3798 struct sctp_chunk
*repl
;
3800 /* The comment below says that we enter COOKIE-WAIT AFTER
3801 * sending the INIT, but that doesn't actually work in our
3804 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3805 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
3807 /* RFC 2960 5.1 Normal Establishment of an Association
3809 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3810 * must provide its Verification Tag (Tag_A) in the Initiate
3811 * Tag field. Tag_A SHOULD be a random number in the range of
3812 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3815 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
3819 /* Cast away the const modifier, as we want to just
3820 * rerun it through as a sideffect.
3822 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
,
3823 SCTP_ASOC((struct sctp_association
*) asoc
));
3825 /* Choose transport for INIT. */
3826 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
3829 /* After sending the INIT, "A" starts the T1-init timer and
3830 * enters the COOKIE-WAIT state.
3832 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
3833 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
3834 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
3835 return SCTP_DISPOSITION_CONSUME
;
3838 return SCTP_DISPOSITION_NOMEM
;
3842 * Process the SEND primitive.
3844 * Section: 10.1 ULP-to-SCTP
3847 * Format: SEND(association id, buffer address, byte count [,context]
3848 * [,stream id] [,life time] [,destination transport address]
3849 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3852 * This is the main method to send user data via SCTP.
3854 * Mandatory attributes:
3856 * o association id - local handle to the SCTP association
3858 * o buffer address - the location where the user message to be
3859 * transmitted is stored;
3861 * o byte count - The size of the user data in number of bytes;
3863 * Optional attributes:
3865 * o context - an optional 32 bit integer that will be carried in the
3866 * sending failure notification to the ULP if the transportation of
3867 * this User Message fails.
3869 * o stream id - to indicate which stream to send the data on. If not
3870 * specified, stream 0 will be used.
3872 * o life time - specifies the life time of the user data. The user data
3873 * will not be sent by SCTP after the life time expires. This
3874 * parameter can be used to avoid efforts to transmit stale
3875 * user messages. SCTP notifies the ULP if the data cannot be
3876 * initiated to transport (i.e. sent to the destination via SCTP's
3877 * send primitive) within the life time variable. However, the
3878 * user data will be transmitted if SCTP has attempted to transmit a
3879 * chunk before the life time expired.
3881 * o destination transport address - specified as one of the destination
3882 * transport addresses of the peer endpoint to which this packet
3883 * should be sent. Whenever possible, SCTP should use this destination
3884 * transport address for sending the packets, instead of the current
3887 * o unorder flag - this flag, if present, indicates that the user
3888 * would like the data delivered in an unordered fashion to the peer
3889 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3892 * o no-bundle flag - instructs SCTP not to bundle this user data with
3893 * other outbound DATA chunks. SCTP MAY still bundle even when
3894 * this flag is present, when faced with network congestion.
3896 * o payload protocol-id - A 32 bit unsigned integer that is to be
3897 * passed to the peer indicating the type of payload protocol data
3898 * being transmitted. This value is passed as opaque data by SCTP.
3900 * The return value is the disposition.
3902 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
3903 const struct sctp_association
*asoc
,
3904 const sctp_subtype_t type
,
3906 sctp_cmd_seq_t
*commands
)
3908 struct sctp_chunk
*chunk
= arg
;
3910 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
3911 return SCTP_DISPOSITION_CONSUME
;
3915 * Process the SHUTDOWN primitive.
3920 * Format: SHUTDOWN(association id)
3923 * Gracefully closes an association. Any locally queued user data
3924 * will be delivered to the peer. The association will be terminated only
3925 * after the peer acknowledges all the SCTP packets sent. A success code
3926 * will be returned on successful termination of the association. If
3927 * attempting to terminate the association results in a failure, an error
3928 * code shall be returned.
3930 * Mandatory attributes:
3932 * o association id - local handle to the SCTP association
3934 * Optional attributes:
3938 * The return value is the disposition.
3940 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
3941 const struct sctp_endpoint
*ep
,
3942 const struct sctp_association
*asoc
,
3943 const sctp_subtype_t type
,
3945 sctp_cmd_seq_t
*commands
)
3949 /* From 9.2 Shutdown of an Association
3950 * Upon receipt of the SHUTDOWN primitive from its upper
3951 * layer, the endpoint enters SHUTDOWN-PENDING state and
3952 * remains there until all outstanding data has been
3953 * acknowledged by its peer. The endpoint accepts no new data
3954 * from its upper layer, but retransmits data to the far end
3955 * if necessary to fill gaps.
3957 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3958 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
3960 /* sctpimpguide-05 Section 2.12.2
3961 * The sender of the SHUTDOWN MAY also start an overall guard timer
3962 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3964 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
3965 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3967 disposition
= SCTP_DISPOSITION_CONSUME
;
3968 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
3969 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
3976 * Process the ABORT primitive.
3981 * Format: Abort(association id [, cause code])
3984 * Ungracefully closes an association. Any locally queued user data
3985 * will be discarded and an ABORT chunk is sent to the peer. A success code
3986 * will be returned on successful abortion of the association. If
3987 * attempting to abort the association results in a failure, an error
3988 * code shall be returned.
3990 * Mandatory attributes:
3992 * o association id - local handle to the SCTP association
3994 * Optional attributes:
3996 * o cause code - reason of the abort to be passed to the peer
4000 * The return value is the disposition.
4002 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4003 const struct sctp_endpoint
*ep
,
4004 const struct sctp_association
*asoc
,
4005 const sctp_subtype_t type
,
4007 sctp_cmd_seq_t
*commands
)
4009 /* From 9.1 Abort of an Association
4010 * Upon receipt of the ABORT primitive from its upper
4011 * layer, the endpoint enters CLOSED state and
4012 * discard all outstanding data has been
4013 * acknowledged by its peer. The endpoint accepts no new data
4014 * from its upper layer, but retransmits data to the far end
4015 * if necessary to fill gaps.
4017 struct msghdr
*msg
= arg
;
4018 struct sctp_chunk
*abort
;
4019 sctp_disposition_t retval
;
4021 retval
= SCTP_DISPOSITION_CONSUME
;
4023 /* Generate ABORT chunk to send the peer. */
4024 abort
= sctp_make_abort_user(asoc
, NULL
, msg
);
4026 retval
= SCTP_DISPOSITION_NOMEM
;
4028 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4030 /* Even if we can't send the ABORT due to low memory delete the
4031 * TCB. This is a departure from our typical NOMEM handling.
4034 /* Delete the established association. */
4035 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4036 SCTP_U32(SCTP_ERROR_USER_ABORT
));
4038 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4039 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4044 /* We tried an illegal operation on an association which is closed. */
4045 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4046 const struct sctp_association
*asoc
,
4047 const sctp_subtype_t type
,
4049 sctp_cmd_seq_t
*commands
)
4051 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4052 return SCTP_DISPOSITION_CONSUME
;
4055 /* We tried an illegal operation on an association which is shutting
4058 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4059 const struct sctp_association
*asoc
,
4060 const sctp_subtype_t type
,
4062 sctp_cmd_seq_t
*commands
)
4064 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4065 SCTP_ERROR(-ESHUTDOWN
));
4066 return SCTP_DISPOSITION_CONSUME
;
4070 * sctp_cookie_wait_prm_shutdown
4072 * Section: 4 Note: 2
4077 * The RFC does not explicitly address this issue, but is the route through the
4078 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4083 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4084 const struct sctp_endpoint
*ep
,
4085 const struct sctp_association
*asoc
,
4086 const sctp_subtype_t type
,
4088 sctp_cmd_seq_t
*commands
)
4090 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4091 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4093 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4094 SCTP_STATE(SCTP_STATE_CLOSED
));
4096 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4098 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4100 return SCTP_DISPOSITION_DELETE_TCB
;
4104 * sctp_cookie_echoed_prm_shutdown
4106 * Section: 4 Note: 2
4111 * The RFC does not explcitly address this issue, but is the route through the
4112 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4117 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4118 const struct sctp_endpoint
*ep
,
4119 const struct sctp_association
*asoc
,
4120 const sctp_subtype_t type
,
4121 void *arg
, sctp_cmd_seq_t
*commands
)
4123 /* There is a single T1 timer, so we should be able to use
4124 * common function with the COOKIE-WAIT state.
4126 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4130 * sctp_sf_cookie_wait_prm_abort
4132 * Section: 4 Note: 2
4137 * The RFC does not explicitly address this issue, but is the route through the
4138 * state table when someone issues an abort while in COOKIE_WAIT state.
4143 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4144 const struct sctp_endpoint
*ep
,
4145 const struct sctp_association
*asoc
,
4146 const sctp_subtype_t type
,
4148 sctp_cmd_seq_t
*commands
)
4150 struct msghdr
*msg
= arg
;
4151 struct sctp_chunk
*abort
;
4152 sctp_disposition_t retval
;
4154 /* Stop T1-init timer */
4155 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4156 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4157 retval
= SCTP_DISPOSITION_CONSUME
;
4159 /* Generate ABORT chunk to send the peer */
4160 abort
= sctp_make_abort_user(asoc
, NULL
, msg
);
4162 retval
= SCTP_DISPOSITION_NOMEM
;
4164 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4166 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4167 SCTP_STATE(SCTP_STATE_CLOSED
));
4169 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4171 /* Even if we can't send the ABORT due to low memory delete the
4172 * TCB. This is a departure from our typical NOMEM handling.
4175 /* Delete the established association. */
4176 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4177 SCTP_U32(SCTP_ERROR_USER_ABORT
));
4183 * sctp_sf_cookie_echoed_prm_abort
4185 * Section: 4 Note: 3
4190 * The RFC does not explcitly address this issue, but is the route through the
4191 * state table when someone issues an abort while in COOKIE_ECHOED state.
4196 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4197 const struct sctp_endpoint
*ep
,
4198 const struct sctp_association
*asoc
,
4199 const sctp_subtype_t type
,
4201 sctp_cmd_seq_t
*commands
)
4203 /* There is a single T1 timer, so we should be able to use
4204 * common function with the COOKIE-WAIT state.
4206 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4210 * sctp_sf_shutdown_pending_prm_abort
4215 * The RFC does not explicitly address this issue, but is the route through the
4216 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4221 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4222 const struct sctp_endpoint
*ep
,
4223 const struct sctp_association
*asoc
,
4224 const sctp_subtype_t type
,
4226 sctp_cmd_seq_t
*commands
)
4228 /* Stop the T5-shutdown guard timer. */
4229 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4230 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4232 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4236 * sctp_sf_shutdown_sent_prm_abort
4241 * The RFC does not explicitly address this issue, but is the route through the
4242 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4247 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4248 const struct sctp_endpoint
*ep
,
4249 const struct sctp_association
*asoc
,
4250 const sctp_subtype_t type
,
4252 sctp_cmd_seq_t
*commands
)
4254 /* Stop the T2-shutdown timer. */
4255 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4256 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4258 /* Stop the T5-shutdown guard timer. */
4259 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4260 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4262 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4266 * sctp_sf_cookie_echoed_prm_abort
4271 * The RFC does not explcitly address this issue, but is the route through the
4272 * state table when someone issues an abort while in COOKIE_ECHOED state.
4277 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4278 const struct sctp_endpoint
*ep
,
4279 const struct sctp_association
*asoc
,
4280 const sctp_subtype_t type
,
4282 sctp_cmd_seq_t
*commands
)
4284 /* The same T2 timer, so we should be able to use
4285 * common function with the SHUTDOWN-SENT state.
4287 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
4291 * Process the REQUESTHEARTBEAT primitive
4294 * J) Request Heartbeat
4296 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4300 * Instructs the local endpoint to perform a HeartBeat on the specified
4301 * destination transport address of the given association. The returned
4302 * result should indicate whether the transmission of the HEARTBEAT
4303 * chunk to the destination address is successful.
4305 * Mandatory attributes:
4307 * o association id - local handle to the SCTP association
4309 * o destination transport address - the transport address of the
4310 * association on which a heartbeat should be issued.
4312 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
4313 const struct sctp_endpoint
*ep
,
4314 const struct sctp_association
*asoc
,
4315 const sctp_subtype_t type
,
4317 sctp_cmd_seq_t
*commands
)
4319 return sctp_sf_heartbeat(ep
, asoc
, type
, (struct sctp_transport
*)arg
,
4324 * ADDIP Section 4.1 ASCONF Chunk Procedures
4325 * When an endpoint has an ASCONF signaled change to be sent to the
4326 * remote endpoint it should do A1 to A9
4328 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
4329 const struct sctp_association
*asoc
,
4330 const sctp_subtype_t type
,
4332 sctp_cmd_seq_t
*commands
)
4334 struct sctp_chunk
*chunk
= arg
;
4336 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
4337 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4338 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4339 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
4340 return SCTP_DISPOSITION_CONSUME
;
4344 * Ignore the primitive event
4346 * The return value is the disposition of the primitive.
4348 sctp_disposition_t
sctp_sf_ignore_primitive(
4349 const struct sctp_endpoint
*ep
,
4350 const struct sctp_association
*asoc
,
4351 const sctp_subtype_t type
,
4353 sctp_cmd_seq_t
*commands
)
4355 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
4356 return SCTP_DISPOSITION_DISCARD
;
4359 /***************************************************************************
4360 * These are the state functions for the OTHER events.
4361 ***************************************************************************/
4364 * Start the shutdown negotiation.
4367 * Once all its outstanding data has been acknowledged, the endpoint
4368 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4369 * TSN Ack field the last sequential TSN it has received from the peer.
4370 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4371 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4372 * with the updated last sequential TSN received from its peer.
4374 * The return value is the disposition.
4376 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
4377 const struct sctp_endpoint
*ep
,
4378 const struct sctp_association
*asoc
,
4379 const sctp_subtype_t type
,
4381 sctp_cmd_seq_t
*commands
)
4383 struct sctp_chunk
*reply
;
4385 /* Once all its outstanding data has been acknowledged, the
4386 * endpoint shall send a SHUTDOWN chunk to its peer including
4387 * in the Cumulative TSN Ack field the last sequential TSN it
4388 * has received from the peer.
4390 reply
= sctp_make_shutdown(asoc
, NULL
);
4394 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4395 * T2-shutdown timer.
4397 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4399 /* It shall then start the T2-shutdown timer */
4400 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4401 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4403 if (asoc
->autoclose
)
4404 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4405 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
4407 /* and enter the SHUTDOWN-SENT state. */
4408 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4409 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
4411 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4413 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4416 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
4418 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4420 return SCTP_DISPOSITION_CONSUME
;
4423 return SCTP_DISPOSITION_NOMEM
;
4427 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4431 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4432 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4433 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4434 * endpoint must re-send the SHUTDOWN ACK.
4436 * The return value is the disposition.
4438 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
4439 const struct sctp_endpoint
*ep
,
4440 const struct sctp_association
*asoc
,
4441 const sctp_subtype_t type
,
4443 sctp_cmd_seq_t
*commands
)
4445 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
4446 struct sctp_chunk
*reply
;
4448 /* There are 2 ways of getting here:
4449 * 1) called in response to a SHUTDOWN chunk
4450 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4452 * For the case (2), the arg parameter is set to NULL. We need
4453 * to check that we have a chunk before accessing it's fields.
4456 if (!sctp_vtag_verify(chunk
, asoc
))
4457 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4459 /* Make sure that the SHUTDOWN chunk has a valid length. */
4460 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
4461 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4465 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4466 * shall send a SHUTDOWN ACK ...
4468 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
4472 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4473 * the T2-shutdown timer.
4475 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4477 /* and start/restart a T2-shutdown timer of its own, */
4478 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4479 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4481 if (asoc
->autoclose
)
4482 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4483 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
4485 /* Enter the SHUTDOWN-ACK-SENT state. */
4486 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4487 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
4489 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4491 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4494 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
4496 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4498 return SCTP_DISPOSITION_CONSUME
;
4501 return SCTP_DISPOSITION_NOMEM
;
4505 * Ignore the event defined as other
4507 * The return value is the disposition of the event.
4509 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
4510 const struct sctp_association
*asoc
,
4511 const sctp_subtype_t type
,
4513 sctp_cmd_seq_t
*commands
)
4515 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
4516 return SCTP_DISPOSITION_DISCARD
;
4519 /************************************************************
4520 * These are the state functions for handling timeout events.
4521 ************************************************************/
4526 * Section: 6.3.3 Handle T3-rtx Expiration
4528 * Whenever the retransmission timer T3-rtx expires for a destination
4529 * address, do the following:
4532 * The return value is the disposition of the chunk.
4534 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
4535 const struct sctp_association
*asoc
,
4536 const sctp_subtype_t type
,
4538 sctp_cmd_seq_t
*commands
)
4540 struct sctp_transport
*transport
= arg
;
4542 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4543 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4544 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4545 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4546 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4547 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4548 return SCTP_DISPOSITION_DELETE_TCB
;
4551 /* E1) For the destination address for which the timer
4552 * expires, adjust its ssthresh with rules defined in Section
4553 * 7.2.3 and set the cwnd <- MTU.
4556 /* E2) For the destination address for which the timer
4557 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4558 * maximum value discussed in rule C7 above (RTO.max) may be
4559 * used to provide an upper bound to this doubling operation.
4562 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4563 * outstanding DATA chunks for the address for which the
4564 * T3-rtx has expired will fit into a single packet, subject
4565 * to the MTU constraint for the path corresponding to the
4566 * destination transport address to which the retransmission
4567 * is being sent (this may be different from the address for
4568 * which the timer expires [see Section 6.4]). Call this
4569 * value K. Bundle and retransmit those K DATA chunks in a
4570 * single packet to the destination endpoint.
4572 * Note: Any DATA chunks that were sent to the address for
4573 * which the T3-rtx timer expired but did not fit in one MTU
4574 * (rule E3 above), should be marked for retransmission and
4575 * sent as soon as cwnd allows (normally when a SACK arrives).
4578 /* NB: Rules E4 and F1 are implicit in R1. */
4579 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
4581 /* Do some failure management (Section 8.2). */
4582 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
4584 return SCTP_DISPOSITION_CONSUME
;
4588 * Generate delayed SACK on timeout
4590 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4592 * The guidelines on delayed acknowledgement algorithm specified in
4593 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4594 * acknowledgement SHOULD be generated for at least every second packet
4595 * (not every second DATA chunk) received, and SHOULD be generated
4596 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4597 * some situations it may be beneficial for an SCTP transmitter to be
4598 * more conservative than the algorithms detailed in this document
4599 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4600 * the following algorithms allow.
4602 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
4603 const struct sctp_association
*asoc
,
4604 const sctp_subtype_t type
,
4606 sctp_cmd_seq_t
*commands
)
4608 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
4609 return SCTP_DISPOSITION_CONSUME
;
4613 * sctp_sf_t1_init_timer_expire
4615 * Section: 4 Note: 2
4620 * RFC 2960 Section 4 Notes
4621 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4622 * and re-start the T1-init timer without changing state. This MUST
4623 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4624 * endpoint MUST abort the initialization process and report the
4625 * error to SCTP user.
4631 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
4632 const struct sctp_association
*asoc
,
4633 const sctp_subtype_t type
,
4635 sctp_cmd_seq_t
*commands
)
4637 struct sctp_chunk
*repl
= NULL
;
4638 struct sctp_bind_addr
*bp
;
4639 int attempts
= asoc
->init_err_counter
+ 1;
4641 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4643 if (attempts
<= asoc
->max_init_attempts
) {
4644 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
4645 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
4647 return SCTP_DISPOSITION_NOMEM
;
4649 /* Choose transport for INIT. */
4650 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4653 /* Issue a sideeffect to do the needed accounting. */
4654 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
4655 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4657 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4659 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4660 " max_init_attempts: %d\n",
4661 attempts
, asoc
->max_init_attempts
);
4662 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4663 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4664 return SCTP_DISPOSITION_DELETE_TCB
;
4667 return SCTP_DISPOSITION_CONSUME
;
4671 * sctp_sf_t1_cookie_timer_expire
4673 * Section: 4 Note: 2
4678 * RFC 2960 Section 4 Notes
4679 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
4680 * COOKIE ECHO and re-start the T1-cookie timer without changing
4681 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4682 * After that, the endpoint MUST abort the initialization process and
4683 * report the error to SCTP user.
4689 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
4690 const struct sctp_association
*asoc
,
4691 const sctp_subtype_t type
,
4693 sctp_cmd_seq_t
*commands
)
4695 struct sctp_chunk
*repl
= NULL
;
4696 int attempts
= asoc
->init_err_counter
+ 1;
4698 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
4700 if (attempts
<= asoc
->max_init_attempts
) {
4701 repl
= sctp_make_cookie_echo(asoc
, NULL
);
4703 return SCTP_DISPOSITION_NOMEM
;
4705 /* Issue a sideeffect to do the needed accounting. */
4706 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
4707 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
4709 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4711 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4712 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4713 return SCTP_DISPOSITION_DELETE_TCB
;
4716 return SCTP_DISPOSITION_CONSUME
;
4719 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4720 * with the updated last sequential TSN received from its peer.
4722 * An endpoint should limit the number of retransmissions of the
4723 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4724 * If this threshold is exceeded the endpoint should destroy the TCB and
4725 * MUST report the peer endpoint unreachable to the upper layer (and
4726 * thus the association enters the CLOSED state). The reception of any
4727 * packet from its peer (i.e. as the peer sends all of its queued DATA
4728 * chunks) should clear the endpoint's retransmission count and restart
4729 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4730 * all of its queued DATA chunks that have not yet been sent.
4732 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
4733 const struct sctp_association
*asoc
,
4734 const sctp_subtype_t type
,
4736 sctp_cmd_seq_t
*commands
)
4738 struct sctp_chunk
*reply
= NULL
;
4740 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4741 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4742 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4743 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4744 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4745 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4746 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4747 return SCTP_DISPOSITION_DELETE_TCB
;
4750 switch (asoc
->state
) {
4751 case SCTP_STATE_SHUTDOWN_SENT
:
4752 reply
= sctp_make_shutdown(asoc
, NULL
);
4755 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
4756 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
4767 /* Do some failure management (Section 8.2). */
4768 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
4769 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
4771 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4772 * the T2-shutdown timer.
4774 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4776 /* Restart the T2-shutdown timer. */
4777 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4778 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4779 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4780 return SCTP_DISPOSITION_CONSUME
;
4783 return SCTP_DISPOSITION_NOMEM
;
4787 * ADDIP Section 4.1 ASCONF CHunk Procedures
4788 * If the T4 RTO timer expires the endpoint should do B1 to B5
4790 sctp_disposition_t
sctp_sf_t4_timer_expire(
4791 const struct sctp_endpoint
*ep
,
4792 const struct sctp_association
*asoc
,
4793 const sctp_subtype_t type
,
4795 sctp_cmd_seq_t
*commands
)
4797 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
4798 struct sctp_transport
*transport
= chunk
->transport
;
4800 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4801 * detection on the appropriate destination address as defined in
4802 * RFC2960 [5] section 8.1 and 8.2.
4804 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
4806 /* Reconfig T4 timer and transport. */
4807 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
4809 /* ADDIP 4.1 B2) Increment the association error counters and perform
4810 * endpoint failure detection on the association as defined in
4811 * RFC2960 [5] section 8.1 and 8.2.
4812 * association error counter is incremented in SCTP_CMD_STRIKE.
4814 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4815 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4816 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4817 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4818 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4819 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4820 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
4821 return SCTP_DISPOSITION_ABORT
;
4824 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4825 * the ASCONF chunk was sent by doubling the RTO timer value.
4826 * This is done in SCTP_CMD_STRIKE.
4829 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4830 * choose an alternate destination address (please refer to RFC2960
4831 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4832 * chunk, it MUST be the same (including its serial number) as the last
4835 sctp_chunk_hold(asoc
->addip_last_asconf
);
4836 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4837 SCTP_CHUNK(asoc
->addip_last_asconf
));
4839 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4840 * destination is selected, then the RTO used will be that of the new
4841 * destination address.
4843 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4844 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4846 return SCTP_DISPOSITION_CONSUME
;
4849 /* sctpimpguide-05 Section 2.12.2
4850 * The sender of the SHUTDOWN MAY also start an overall guard timer
4851 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4852 * At the expiration of this timer the sender SHOULD abort the association
4853 * by sending an ABORT chunk.
4855 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
4856 const struct sctp_association
*asoc
,
4857 const sctp_subtype_t type
,
4859 sctp_cmd_seq_t
*commands
)
4861 struct sctp_chunk
*reply
= NULL
;
4863 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4865 reply
= sctp_make_abort(asoc
, NULL
, 0);
4869 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4870 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4871 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4873 return SCTP_DISPOSITION_DELETE_TCB
;
4875 return SCTP_DISPOSITION_NOMEM
;
4878 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4879 * the association is automatically closed by starting the shutdown process.
4880 * The work that needs to be done is same as when SHUTDOWN is initiated by
4881 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4883 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
4884 const struct sctp_endpoint
*ep
,
4885 const struct sctp_association
*asoc
,
4886 const sctp_subtype_t type
,
4888 sctp_cmd_seq_t
*commands
)
4892 /* From 9.2 Shutdown of an Association
4893 * Upon receipt of the SHUTDOWN primitive from its upper
4894 * layer, the endpoint enters SHUTDOWN-PENDING state and
4895 * remains there until all outstanding data has been
4896 * acknowledged by its peer. The endpoint accepts no new data
4897 * from its upper layer, but retransmits data to the far end
4898 * if necessary to fill gaps.
4900 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4901 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4903 /* sctpimpguide-05 Section 2.12.2
4904 * The sender of the SHUTDOWN MAY also start an overall guard timer
4905 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4907 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4908 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4909 disposition
= SCTP_DISPOSITION_CONSUME
;
4910 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4911 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4917 /*****************************************************************************
4918 * These are sa state functions which could apply to all types of events.
4919 ****************************************************************************/
4922 * This table entry is not implemented.
4925 * (endpoint, asoc, chunk)
4927 * The return value is the disposition of the chunk.
4929 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
4930 const struct sctp_association
*asoc
,
4931 const sctp_subtype_t type
,
4933 sctp_cmd_seq_t
*commands
)
4935 return SCTP_DISPOSITION_NOT_IMPL
;
4939 * This table entry represents a bug.
4942 * (endpoint, asoc, chunk)
4944 * The return value is the disposition of the chunk.
4946 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
4947 const struct sctp_association
*asoc
,
4948 const sctp_subtype_t type
,
4950 sctp_cmd_seq_t
*commands
)
4952 return SCTP_DISPOSITION_BUG
;
4956 * This table entry represents the firing of a timer in the wrong state.
4957 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4958 * when the association is in the wrong state. This event should
4959 * be ignored, so as to prevent any rearming of the timer.
4962 * (endpoint, asoc, chunk)
4964 * The return value is the disposition of the chunk.
4966 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
4967 const struct sctp_association
*asoc
,
4968 const sctp_subtype_t type
,
4970 sctp_cmd_seq_t
*commands
)
4972 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
4973 return SCTP_DISPOSITION_CONSUME
;
4976 /********************************************************************
4977 * 2nd Level Abstractions
4978 ********************************************************************/
4980 /* Pull the SACK chunk based on the SACK header. */
4981 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
4983 struct sctp_sackhdr
*sack
;
4988 /* Protect ourselves from reading too far into
4989 * the skb from a bogus sender.
4991 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
4993 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
4994 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
4995 len
= sizeof(struct sctp_sackhdr
);
4996 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
4997 if (len
> chunk
->skb
->len
)
5000 skb_pull(chunk
->skb
, len
);
5005 /* Create an ABORT packet to be sent as a response, with the specified
5008 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5009 const struct sctp_association
*asoc
,
5010 struct sctp_chunk
*chunk
,
5011 const void *payload
,
5014 struct sctp_packet
*packet
;
5015 struct sctp_chunk
*abort
;
5017 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5021 * The T bit will be set if the asoc is NULL.
5023 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5025 sctp_ootb_pkt_free(packet
);
5029 /* Reflect vtag if T-Bit is set */
5030 if (sctp_test_T_bit(abort
))
5031 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5033 /* Add specified error causes, i.e., payload, to the
5036 sctp_addto_chunk(abort
, paylen
, payload
);
5038 /* Set the skb to the belonging sock for accounting. */
5039 abort
->skb
->sk
= ep
->base
.sk
;
5041 sctp_packet_append_chunk(packet
, abort
);
5048 /* Allocate a packet for responding in the OOTB conditions. */
5049 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5050 const struct sctp_chunk
*chunk
)
5052 struct sctp_packet
*packet
;
5053 struct sctp_transport
*transport
;
5058 /* Get the source and destination port from the inbound packet. */
5059 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5060 dport
= ntohs(chunk
->sctp_hdr
->source
);
5062 /* The V-tag is going to be the same as the inbound packet if no
5063 * association exists, otherwise, use the peer's vtag.
5066 vtag
= asoc
->peer
.i
.init_tag
;
5068 /* Special case the INIT and stale COOKIE_ECHO as there is no
5071 switch(chunk
->chunk_hdr
->type
) {
5074 sctp_init_chunk_t
*init
;
5076 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5077 vtag
= ntohl(init
->init_hdr
.init_tag
);
5081 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5086 /* Make a transport for the bucket, Eliza... */
5087 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5091 /* Cache a route for the transport with the chunk's destination as
5092 * the source address.
5094 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5095 sctp_sk(sctp_get_ctl_sock()));
5097 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5098 packet
= sctp_packet_config(packet
, vtag
, 0);
5106 /* Free the packet allocated earlier for responding in the OOTB condition. */
5107 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5109 sctp_transport_free(packet
->transport
);
5112 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5113 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5114 const struct sctp_association
*asoc
,
5115 const struct sctp_chunk
*chunk
,
5116 sctp_cmd_seq_t
*commands
,
5117 struct sctp_chunk
*err_chunk
)
5119 struct sctp_packet
*packet
;
5122 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5124 struct sctp_signed_cookie
*cookie
;
5126 /* Override the OOTB vtag from the cookie. */
5127 cookie
= chunk
->subh
.cookie_hdr
;
5128 packet
->vtag
= cookie
->c
.peer_vtag
;
5130 /* Set the skb to the belonging sock for accounting. */
5131 err_chunk
->skb
->sk
= ep
->base
.sk
;
5132 sctp_packet_append_chunk(packet
, err_chunk
);
5133 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5134 SCTP_PACKET(packet
));
5135 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5137 sctp_chunk_free (err_chunk
);
5142 /* Process a data chunk */
5143 static int sctp_eat_data(const struct sctp_association
*asoc
,
5144 struct sctp_chunk
*chunk
,
5145 sctp_cmd_seq_t
*commands
)
5147 sctp_datahdr_t
*data_hdr
;
5148 struct sctp_chunk
*err
;
5150 sctp_verb_t deliver
;
5154 struct sock
*sk
= asoc
->base
.sk
;
5156 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5157 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5159 tsn
= ntohl(data_hdr
->tsn
);
5160 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5162 /* ASSERT: Now skb->data is really the user data. */
5165 * if we are established, and we have used up our receive
5166 * buffer memory, drop the frame
5168 if (asoc
->state
== SCTP_STATE_ESTABLISHED
) {
5170 * If the receive buffer policy is 1, then each
5171 * association can allocate up to sk_rcvbuf bytes
5172 * otherwise, all the associations in aggregate
5173 * may allocate up to sk_rcvbuf bytes
5175 if (asoc
->ep
->rcvbuf_policy
)
5176 account_value
= atomic_read(&asoc
->rmem_alloc
);
5178 account_value
= atomic_read(&sk
->sk_rmem_alloc
);
5180 if (account_value
> sk
->sk_rcvbuf
)
5181 return SCTP_IERROR_IGNORE_TSN
;
5184 /* Process ECN based congestion.
5186 * Since the chunk structure is reused for all chunks within
5187 * a packet, we use ecn_ce_done to track if we've already
5188 * done CE processing for this packet.
5190 * We need to do ECN processing even if we plan to discard the
5194 if (!chunk
->ecn_ce_done
) {
5196 chunk
->ecn_ce_done
= 1;
5198 af
= sctp_get_af_specific(
5199 ipver2af(chunk
->skb
->nh
.iph
->version
));
5201 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
5202 /* Do real work as sideffect. */
5203 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
5208 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
5210 /* The TSN is too high--silently discard the chunk and
5211 * count on it getting retransmitted later.
5213 return SCTP_IERROR_HIGH_TSN
;
5214 } else if (tmp
> 0) {
5215 /* This is a duplicate. Record it. */
5216 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
5217 return SCTP_IERROR_DUP_TSN
;
5220 /* This is a new TSN. */
5222 /* Discard if there is no room in the receive window.
5223 * Actually, allow a little bit of overflow (up to a MTU).
5225 datalen
= ntohs(chunk
->chunk_hdr
->length
);
5226 datalen
-= sizeof(sctp_data_chunk_t
);
5228 deliver
= SCTP_CMD_CHUNK_ULP
;
5230 /* Think about partial delivery. */
5231 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
5233 /* Even if we don't accept this chunk there is
5236 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
5239 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5240 * seems a bit troublesome in that frag_point varies based on
5241 * PMTU. In cases, such as loopback, this might be a rather
5244 if (!asoc
->rwnd
|| asoc
->rwnd_over
||
5245 (datalen
> asoc
->rwnd
+ asoc
->frag_point
)) {
5247 /* If this is the next TSN, consider reneging to make
5248 * room. Note: Playing nice with a confused sender. A
5249 * malicious sender can still eat up all our buffer
5250 * space and in the future we may want to detect and
5251 * do more drastic reneging.
5253 if (sctp_tsnmap_has_gap(&asoc
->peer
.tsn_map
) &&
5254 (sctp_tsnmap_get_ctsn(&asoc
->peer
.tsn_map
) + 1) == tsn
) {
5255 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
5256 deliver
= SCTP_CMD_RENEGE
;
5258 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5259 "rwnd: %d\n", tsn
, datalen
,
5261 return SCTP_IERROR_IGNORE_TSN
;
5266 * Section 3.3.10.9 No User Data (9)
5270 * No User Data: This error cause is returned to the originator of a
5271 * DATA chunk if a received DATA chunk has no user data.
5273 if (unlikely(0 == datalen
)) {
5274 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
5276 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5279 /* We are going to ABORT, so we might as well stop
5280 * processing the rest of the chunks in the packet.
5282 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
5283 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5284 SCTP_U32(SCTP_ERROR_NO_DATA
));
5285 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5286 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5287 return SCTP_IERROR_NO_DATA
;
5290 /* If definately accepting the DATA chunk, record its TSN, otherwise
5291 * wait for renege processing.
5293 if (SCTP_CMD_CHUNK_ULP
== deliver
)
5294 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
5296 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5297 * if we renege and the chunk arrives again.
5299 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
5300 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
5302 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
5304 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5306 * If an endpoint receive a DATA chunk with an invalid stream
5307 * identifier, it shall acknowledge the reception of the DATA chunk
5308 * following the normal procedure, immediately send an ERROR chunk
5309 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5310 * and discard the DATA chunk.
5312 if (ntohs(data_hdr
->stream
) >= asoc
->c
.sinit_max_instreams
) {
5313 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
5315 sizeof(data_hdr
->stream
));
5317 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5319 return SCTP_IERROR_BAD_STREAM
;
5322 /* Send the data up to the user. Note: Schedule the
5323 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5324 * chunk needs the updated rwnd.
5326 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
5328 return SCTP_IERROR_NO_ERROR
;