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
);
96 /* Small helper function that checks if the chunk length
97 * is of the appropriate length. The 'required_length' argument
98 * is set to be the size of a specific chunk we are testing.
99 * Return Values: 1 = Valid length
104 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
105 __u16 required_length
)
107 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
109 if (unlikely(chunk_length
< required_length
))
115 /**********************************************************
116 * These are the state functions for handling chunk events.
117 **********************************************************/
120 * Process the final SHUTDOWN COMPLETE.
122 * Section: 4 (C) (diagram), 9.2
123 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
124 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
125 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
126 * should stop the T2-shutdown timer and remove all knowledge of the
127 * association (and thus the association enters the CLOSED state).
129 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
130 * C) Rules for packet carrying SHUTDOWN COMPLETE:
132 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
133 * if the Verification Tag field of the packet matches its own tag and
134 * the T bit is not set
136 * it is set to its peer's tag and the T bit is set in the Chunk
138 * Otherwise, the receiver MUST silently discard the packet
139 * and take no further action. An endpoint MUST ignore the
140 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
143 * (endpoint, asoc, chunk)
146 * (asoc, reply_msg, msg_up, timers, counters)
148 * The return value is the disposition of the chunk.
150 sctp_disposition_t
sctp_sf_do_4_C(const struct sctp_endpoint
*ep
,
151 const struct sctp_association
*asoc
,
152 const sctp_subtype_t type
,
154 sctp_cmd_seq_t
*commands
)
156 struct sctp_chunk
*chunk
= arg
;
157 struct sctp_ulpevent
*ev
;
159 /* RFC 2960 6.10 Bundling
161 * An endpoint MUST NOT bundle INIT, INIT ACK or
162 * SHUTDOWN COMPLETE with any other chunks.
164 if (!chunk
->singleton
)
165 return SCTP_DISPOSITION_VIOLATION
;
167 if (!sctp_vtag_verify_either(chunk
, asoc
))
168 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
170 /* RFC 2960 10.2 SCTP-to-ULP
172 * H) SHUTDOWN COMPLETE notification
174 * When SCTP completes the shutdown procedures (section 9.2) this
175 * notification is passed to the upper layer.
177 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
178 0, 0, 0, GFP_ATOMIC
);
182 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
184 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
185 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
186 * not the chunk should be discarded. If the endpoint is in
187 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
188 * T2-shutdown timer and remove all knowledge of the
189 * association (and thus the association enters the CLOSED
192 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
193 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
195 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
196 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
198 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
199 SCTP_STATE(SCTP_STATE_CLOSED
));
201 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
202 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
204 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
206 return SCTP_DISPOSITION_DELETE_TCB
;
209 return SCTP_DISPOSITION_NOMEM
;
213 * Respond to a normal INIT chunk.
214 * We are the side that is being asked for an association.
216 * Section: 5.1 Normal Establishment of an Association, B
217 * B) "Z" shall respond immediately with an INIT ACK chunk. The
218 * destination IP address of the INIT ACK MUST be set to the source
219 * IP address of the INIT to which this INIT ACK is responding. In
220 * the response, besides filling in other parameters, "Z" must set the
221 * Verification Tag field to Tag_A, and also provide its own
222 * Verification Tag (Tag_Z) in the Initiate Tag field.
224 * Verification Tag: Must be 0.
227 * (endpoint, asoc, chunk)
230 * (asoc, reply_msg, msg_up, timers, counters)
232 * The return value is the disposition of the chunk.
234 sctp_disposition_t
sctp_sf_do_5_1B_init(const struct sctp_endpoint
*ep
,
235 const struct sctp_association
*asoc
,
236 const sctp_subtype_t type
,
238 sctp_cmd_seq_t
*commands
)
240 struct sctp_chunk
*chunk
= arg
;
241 struct sctp_chunk
*repl
;
242 struct sctp_association
*new_asoc
;
243 struct sctp_chunk
*err_chunk
;
244 struct sctp_packet
*packet
;
245 sctp_unrecognized_param_t
*unk_param
;
250 * An endpoint MUST NOT bundle INIT, INIT ACK or
251 * SHUTDOWN COMPLETE with any other chunks.
254 * Furthermore, we require that the receiver of an INIT chunk MUST
255 * enforce these rules by silently discarding an arriving packet
256 * with an INIT chunk that is bundled with other chunks.
258 if (!chunk
->singleton
)
259 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
261 /* If the packet is an OOTB packet which is temporarily on the
262 * control endpoint, respond with an ABORT.
264 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
265 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
268 /* If the endpoint is not listening or if the number of associations
269 * on the TCP-style socket exceed the max backlog, respond with an
272 if (!sctp_sstate(sk
, LISTENING
) ||
273 (sctp_style(sk
, TCP
) &&
274 sk_acceptq_is_full(sk
)))
275 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
277 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
280 if (chunk
->sctp_hdr
->vtag
!= 0)
281 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
283 /* Make sure that the INIT chunk has a valid length.
284 * Normally, this would cause an ABORT with a Protocol Violation
285 * error, but since we don't have an association, we'll
286 * just discard the packet.
288 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
289 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
291 /* Verify the INIT chunk before processing it. */
293 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
294 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
296 /* This chunk contains fatal error. It is to be discarded.
297 * Send an ABORT, with causes if there is any.
300 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
301 (__u8
*)(err_chunk
->chunk_hdr
) +
302 sizeof(sctp_chunkhdr_t
),
303 ntohs(err_chunk
->chunk_hdr
->length
) -
304 sizeof(sctp_chunkhdr_t
));
306 sctp_chunk_free(err_chunk
);
309 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
310 SCTP_PACKET(packet
));
311 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
312 return SCTP_DISPOSITION_CONSUME
;
314 return SCTP_DISPOSITION_NOMEM
;
317 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
322 /* Grab the INIT header. */
323 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
325 /* Tag the variable length parameters. */
326 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
328 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
332 /* The call, sctp_process_init(), can fail on memory allocation. */
333 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
335 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
339 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
341 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
343 /* If there are errors need to be reported for unknown parameters,
344 * make sure to reserve enough room in the INIT ACK for them.
348 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
349 sizeof(sctp_chunkhdr_t
);
351 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
354 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
358 /* If there are errors need to be reported for unknown parameters,
359 * include them in the outgoing INIT ACK as "Unrecognized parameter"
363 /* Get the "Unrecognized parameter" parameter(s) out of the
364 * ERROR chunk generated by sctp_verify_init(). Since the
365 * error cause code for "unknown parameter" and the
366 * "Unrecognized parameter" type is the same, we can
367 * construct the parameters in INIT ACK by copying the
370 unk_param
= (sctp_unrecognized_param_t
*)
371 ((__u8
*)(err_chunk
->chunk_hdr
) +
372 sizeof(sctp_chunkhdr_t
));
373 /* Replace the cause code with the "Unrecognized parameter"
376 sctp_addto_chunk(repl
, len
, unk_param
);
377 sctp_chunk_free(err_chunk
);
380 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
383 * Note: After sending out INIT ACK with the State Cookie parameter,
384 * "Z" MUST NOT allocate any resources, nor keep any states for the
385 * new association. Otherwise, "Z" will be vulnerable to resource
388 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
390 return SCTP_DISPOSITION_DELETE_TCB
;
394 sctp_chunk_free(err_chunk
);
396 sctp_association_free(new_asoc
);
398 return SCTP_DISPOSITION_NOMEM
;
402 * Respond to a normal INIT ACK chunk.
403 * We are the side that is initiating the association.
405 * Section: 5.1 Normal Establishment of an Association, C
406 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
407 * timer and leave COOKIE-WAIT state. "A" shall then send the State
408 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
409 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
411 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
412 * DATA chunks, but it MUST be the first chunk in the packet and
413 * until the COOKIE ACK is returned the sender MUST NOT send any
414 * other packets to the peer.
416 * Verification Tag: 3.3.3
417 * If the value of the Initiate Tag in a received INIT ACK chunk is
418 * found to be 0, the receiver MUST treat it as an error and close the
419 * association by transmitting an ABORT.
422 * (endpoint, asoc, chunk)
425 * (asoc, reply_msg, msg_up, timers, counters)
427 * The return value is the disposition of the chunk.
429 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
430 const struct sctp_association
*asoc
,
431 const sctp_subtype_t type
,
433 sctp_cmd_seq_t
*commands
)
435 struct sctp_chunk
*chunk
= arg
;
436 sctp_init_chunk_t
*initchunk
;
438 struct sctp_chunk
*err_chunk
;
439 struct sctp_packet
*packet
;
440 sctp_disposition_t ret
;
442 if (!sctp_vtag_verify(chunk
, asoc
))
443 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
445 /* Make sure that the INIT-ACK chunk has a valid length */
446 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
447 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
450 * An endpoint MUST NOT bundle INIT, INIT ACK or
451 * SHUTDOWN COMPLETE with any other chunks.
453 if (!chunk
->singleton
)
454 return SCTP_DISPOSITION_VIOLATION
;
456 /* Grab the INIT header. */
457 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
459 init_tag
= ntohl(chunk
->subh
.init_hdr
->init_tag
);
461 /* Verification Tag: 3.3.3
462 * If the value of the Initiate Tag in a received INIT ACK
463 * chunk is found to be 0, the receiver MUST treat it as an
464 * error and close the association by transmitting an ABORT.
467 struct sctp_chunk
*reply
= sctp_make_abort(asoc
, chunk
, 0);
471 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
472 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
473 SCTP_STATE(SCTP_STATE_CLOSED
));
474 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
475 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
476 return SCTP_DISPOSITION_DELETE_TCB
;
479 /* Verify the INIT chunk before processing it. */
481 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
482 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
485 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
487 /* This chunk contains fatal error. It is to be discarded.
488 * Send an ABORT, with causes if there is any.
491 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
492 (__u8
*)(err_chunk
->chunk_hdr
) +
493 sizeof(sctp_chunkhdr_t
),
494 ntohs(err_chunk
->chunk_hdr
->length
) -
495 sizeof(sctp_chunkhdr_t
));
497 sctp_chunk_free(err_chunk
);
500 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
501 SCTP_PACKET(packet
));
502 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
503 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
504 SCTP_STATE(SCTP_STATE_CLOSED
));
505 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
507 return SCTP_DISPOSITION_CONSUME
;
509 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
510 SCTP_STATE(SCTP_STATE_CLOSED
));
511 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
513 return SCTP_DISPOSITION_NOMEM
;
516 ret
= sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
518 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
519 SCTP_STATE(SCTP_STATE_CLOSED
));
520 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
,
526 /* Tag the variable length parameters. Note that we never
527 * convert the parameters in an INIT chunk.
529 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
531 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
533 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
534 SCTP_PEER_INIT(initchunk
));
536 /* Reset init error count upon receipt of INIT-ACK. */
537 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
539 /* 5.1 C) "A" shall stop the T1-init timer and leave
540 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
541 * timer, and enter the COOKIE-ECHOED state.
543 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
544 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
545 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
546 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
547 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
548 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
550 /* 5.1 C) "A" shall then send the State Cookie received in the
551 * INIT ACK chunk in a COOKIE ECHO chunk, ...
553 /* If there is any errors to report, send the ERROR chunk generated
554 * for unknown parameters as well.
556 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
557 SCTP_CHUNK(err_chunk
));
559 return SCTP_DISPOSITION_CONSUME
;
562 return SCTP_DISPOSITION_NOMEM
;
566 * Respond to a normal COOKIE ECHO chunk.
567 * We are the side that is being asked for an association.
569 * Section: 5.1 Normal Establishment of an Association, D
570 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
571 * with a COOKIE ACK chunk after building a TCB and moving to
572 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
573 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
574 * chunk MUST be the first chunk in the packet.
576 * IMPLEMENTATION NOTE: An implementation may choose to send the
577 * Communication Up notification to the SCTP user upon reception
578 * of a valid COOKIE ECHO chunk.
580 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
581 * D) Rules for packet carrying a COOKIE ECHO
583 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
584 * Initial Tag received in the INIT ACK.
586 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
589 * (endpoint, asoc, chunk)
592 * (asoc, reply_msg, msg_up, timers, counters)
594 * The return value is the disposition of the chunk.
596 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
597 const struct sctp_association
*asoc
,
598 const sctp_subtype_t type
, void *arg
,
599 sctp_cmd_seq_t
*commands
)
601 struct sctp_chunk
*chunk
= arg
;
602 struct sctp_association
*new_asoc
;
603 sctp_init_chunk_t
*peer_init
;
604 struct sctp_chunk
*repl
;
605 struct sctp_ulpevent
*ev
;
607 struct sctp_chunk
*err_chk_p
;
609 /* If the packet is an OOTB packet which is temporarily on the
610 * control endpoint, respond with an ABORT.
612 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
613 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
615 /* Make sure that the COOKIE_ECHO chunk has a valid length.
616 * In this case, we check that we have enough for at least a
617 * chunk header. More detailed verification is done
618 * in sctp_unpack_cookie().
620 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
621 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
623 /* "Decode" the chunk. We have no optional parameters so we
626 chunk
->subh
.cookie_hdr
=
627 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
629 ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
));
631 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
632 * "Z" will reply with a COOKIE ACK chunk after building a TCB
633 * and moving to the ESTABLISHED state.
635 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
639 * If the re-build failed, what is the proper error path
642 * [We should abort the association. --piggy]
645 /* FIXME: Several errors are possible. A bad cookie should
646 * be silently discarded, but think about logging it too.
649 case -SCTP_IERROR_NOMEM
:
652 case -SCTP_IERROR_STALE_COOKIE
:
653 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
655 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
657 case -SCTP_IERROR_BAD_SIG
:
659 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
663 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
664 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
665 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
666 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
667 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
668 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
670 if (new_asoc
->autoclose
)
671 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
672 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
674 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
676 /* Re-build the bind address for the association is done in
677 * the sctp_unpack_cookie() already.
679 /* This is a brand-new association, so these are not yet side
680 * effects--it is safe to run them here.
682 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
684 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
685 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
686 peer_init
, GFP_ATOMIC
))
689 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
693 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
695 /* RFC 2960 5.1 Normal Establishment of an Association
697 * D) IMPLEMENTATION NOTE: An implementation may choose to
698 * send the Communication Up notification to the SCTP user
699 * upon reception of a valid COOKIE ECHO chunk.
701 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
702 new_asoc
->c
.sinit_num_ostreams
,
703 new_asoc
->c
.sinit_max_instreams
,
708 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
710 /* Sockets API Draft Section 5.3.1.6
711 * When a peer sends a Adaption Layer Indication parameter , SCTP
712 * delivers this notification to inform the application that of the
713 * peers requested adaption layer.
715 if (new_asoc
->peer
.adaption_ind
) {
716 ev
= sctp_ulpevent_make_adaption_indication(new_asoc
,
721 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
725 return SCTP_DISPOSITION_CONSUME
;
728 sctp_chunk_free(repl
);
731 sctp_association_free(new_asoc
);
733 return SCTP_DISPOSITION_NOMEM
;
737 * Respond to a normal COOKIE ACK chunk.
738 * We are the side that is being asked for an association.
740 * RFC 2960 5.1 Normal Establishment of an Association
742 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
743 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
744 * timer. It may also notify its ULP about the successful
745 * establishment of the association with a Communication Up
746 * notification (see Section 10).
750 * (endpoint, asoc, chunk)
753 * (asoc, reply_msg, msg_up, timers, counters)
755 * The return value is the disposition of the chunk.
757 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
758 const struct sctp_association
*asoc
,
759 const sctp_subtype_t type
, void *arg
,
760 sctp_cmd_seq_t
*commands
)
762 struct sctp_chunk
*chunk
= arg
;
763 struct sctp_ulpevent
*ev
;
765 if (!sctp_vtag_verify(chunk
, asoc
))
766 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
768 /* Verify that the chunk length for the COOKIE-ACK is OK.
769 * If we don't do this, any bundled chunks may be junked.
771 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
772 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
775 /* Reset init error count upon receipt of COOKIE-ACK,
776 * to avoid problems with the managemement of this
777 * counter in stale cookie situations when a transition back
778 * from the COOKIE-ECHOED state to the COOKIE-WAIT
779 * state is performed.
781 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
783 /* RFC 2960 5.1 Normal Establishment of an Association
785 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
786 * from the COOKIE-ECHOED state to the ESTABLISHED state,
787 * stopping the T1-cookie timer.
789 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
790 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
791 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
792 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
793 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
794 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
795 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
797 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
798 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
799 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
801 /* It may also notify its ULP about the successful
802 * establishment of the association with a Communication Up
803 * notification (see Section 10).
805 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
806 0, asoc
->c
.sinit_num_ostreams
,
807 asoc
->c
.sinit_max_instreams
,
813 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
815 /* Sockets API Draft Section 5.3.1.6
816 * When a peer sends a Adaption Layer Indication parameter , SCTP
817 * delivers this notification to inform the application that of the
818 * peers requested adaption layer.
820 if (asoc
->peer
.adaption_ind
) {
821 ev
= sctp_ulpevent_make_adaption_indication(asoc
, GFP_ATOMIC
);
825 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
829 return SCTP_DISPOSITION_CONSUME
;
831 return SCTP_DISPOSITION_NOMEM
;
834 /* Generate and sendout a heartbeat packet. */
835 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
836 const struct sctp_association
*asoc
,
837 const sctp_subtype_t type
,
839 sctp_cmd_seq_t
*commands
)
841 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
842 struct sctp_chunk
*reply
;
843 sctp_sender_hb_info_t hbinfo
;
846 hbinfo
.param_hdr
.type
= SCTP_PARAM_HEARTBEAT_INFO
;
847 hbinfo
.param_hdr
.length
= htons(sizeof(sctp_sender_hb_info_t
));
848 hbinfo
.daddr
= transport
->ipaddr
;
849 hbinfo
.sent_at
= jiffies
;
851 /* Send a heartbeat to our peer. */
852 paylen
= sizeof(sctp_sender_hb_info_t
);
853 reply
= sctp_make_heartbeat(asoc
, transport
, &hbinfo
, paylen
);
855 return SCTP_DISPOSITION_NOMEM
;
857 /* Set rto_pending indicating that an RTT measurement
858 * is started with this heartbeat chunk.
860 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
861 SCTP_TRANSPORT(transport
));
863 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
864 return SCTP_DISPOSITION_CONSUME
;
867 /* Generate a HEARTBEAT packet on the given transport. */
868 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
869 const struct sctp_association
*asoc
,
870 const sctp_subtype_t type
,
872 sctp_cmd_seq_t
*commands
)
874 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
876 if (asoc
->overall_error_count
> asoc
->max_retrans
) {
877 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
878 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
879 SCTP_U32(SCTP_ERROR_NO_ERROR
));
880 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
881 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
882 return SCTP_DISPOSITION_DELETE_TCB
;
886 * The Sender-specific Heartbeat Info field should normally include
887 * information about the sender's current time when this HEARTBEAT
888 * chunk is sent and the destination transport address to which this
889 * HEARTBEAT is sent (see Section 8.3).
892 if (transport
->hb_allowed
) {
893 if (SCTP_DISPOSITION_NOMEM
==
894 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
896 return SCTP_DISPOSITION_NOMEM
;
897 /* Set transport error counter and association error counter
898 * when sending heartbeat.
900 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_RESET
,
901 SCTP_TRANSPORT(transport
));
903 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
904 SCTP_TRANSPORT(transport
));
906 return SCTP_DISPOSITION_CONSUME
;
910 * Process an heartbeat request.
912 * Section: 8.3 Path Heartbeat
913 * The receiver of the HEARTBEAT should immediately respond with a
914 * HEARTBEAT ACK that contains the Heartbeat Information field copied
915 * from the received HEARTBEAT chunk.
917 * Verification Tag: 8.5 Verification Tag [Normal verification]
918 * When receiving an SCTP packet, the endpoint MUST ensure that the
919 * value in the Verification Tag field of the received SCTP packet
920 * matches its own Tag. If the received Verification Tag value does not
921 * match the receiver's own tag value, the receiver shall silently
922 * discard the packet and shall not process it any further except for
923 * those cases listed in Section 8.5.1 below.
926 * (endpoint, asoc, chunk)
929 * (asoc, reply_msg, msg_up, timers, counters)
931 * The return value is the disposition of the chunk.
933 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
934 const struct sctp_association
*asoc
,
935 const sctp_subtype_t type
,
937 sctp_cmd_seq_t
*commands
)
939 struct sctp_chunk
*chunk
= arg
;
940 struct sctp_chunk
*reply
;
943 if (!sctp_vtag_verify(chunk
, asoc
))
944 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
946 /* Make sure that the HEARTBEAT chunk has a valid length. */
947 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
948 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
951 /* 8.3 The receiver of the HEARTBEAT should immediately
952 * respond with a HEARTBEAT ACK that contains the Heartbeat
953 * Information field copied from the received HEARTBEAT chunk.
955 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
956 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
957 skb_pull(chunk
->skb
, paylen
);
959 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
960 chunk
->subh
.hb_hdr
, paylen
);
964 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
965 return SCTP_DISPOSITION_CONSUME
;
968 return SCTP_DISPOSITION_NOMEM
;
972 * Process the returning HEARTBEAT ACK.
974 * Section: 8.3 Path Heartbeat
975 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
976 * should clear the error counter of the destination transport
977 * address to which the HEARTBEAT was sent, and mark the destination
978 * transport address as active if it is not so marked. The endpoint may
979 * optionally report to the upper layer when an inactive destination
980 * address is marked as active due to the reception of the latest
981 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
982 * clear the association overall error count as well (as defined
985 * The receiver of the HEARTBEAT ACK should also perform an RTT
986 * measurement for that destination transport address using the time
987 * value carried in the HEARTBEAT ACK chunk.
989 * Verification Tag: 8.5 Verification Tag [Normal verification]
992 * (endpoint, asoc, chunk)
995 * (asoc, reply_msg, msg_up, timers, counters)
997 * The return value is the disposition of the chunk.
999 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1000 const struct sctp_association
*asoc
,
1001 const sctp_subtype_t type
,
1003 sctp_cmd_seq_t
*commands
)
1005 struct sctp_chunk
*chunk
= arg
;
1006 union sctp_addr from_addr
;
1007 struct sctp_transport
*link
;
1008 sctp_sender_hb_info_t
*hbinfo
;
1009 unsigned long max_interval
;
1011 if (!sctp_vtag_verify(chunk
, asoc
))
1012 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1014 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1015 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1016 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1019 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1020 from_addr
= hbinfo
->daddr
;
1021 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1023 /* This should never happen, but lets log it if so. */
1024 if (unlikely(!link
)) {
1025 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1027 "%s association %p could not find address "
1028 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1031 NIP6(from_addr
.v6
.sin6_addr
));
1034 "%s association %p could not find address "
1038 NIPQUAD(from_addr
.v4
.sin_addr
.s_addr
));
1040 return SCTP_DISPOSITION_DISCARD
;
1043 max_interval
= link
->hb_interval
+ link
->rto
;
1045 /* Check if the timestamp looks valid. */
1046 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1047 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1048 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1049 "received for transport: %p\n",
1050 __FUNCTION__
, link
);
1051 return SCTP_DISPOSITION_DISCARD
;
1054 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1055 * the HEARTBEAT should clear the error counter of the
1056 * destination transport address to which the HEARTBEAT was
1057 * sent and mark the destination transport address as active if
1058 * it is not so marked.
1060 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1062 return SCTP_DISPOSITION_CONSUME
;
1065 /* Helper function to send out an abort for the restart
1068 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1069 struct sctp_chunk
*init
,
1070 sctp_cmd_seq_t
*commands
)
1073 struct sctp_packet
*pkt
;
1074 union sctp_addr_param
*addrparm
;
1075 struct sctp_errhdr
*errhdr
;
1076 struct sctp_endpoint
*ep
;
1077 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1078 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1080 /* Build the error on the stack. We are way to malloc crazy
1081 * throughout the code today.
1083 errhdr
= (struct sctp_errhdr
*)buffer
;
1084 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1086 /* Copy into a parm format. */
1087 len
= af
->to_addr_param(ssa
, addrparm
);
1088 len
+= sizeof(sctp_errhdr_t
);
1090 errhdr
->cause
= SCTP_ERROR_RESTART
;
1091 errhdr
->length
= htons(len
);
1093 /* Assign to the control socket. */
1094 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1096 /* Association is NULL since this may be a restart attack and we
1097 * want to send back the attacker's vtag.
1099 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1103 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1105 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1107 /* Discard the rest of the inbound packet. */
1108 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1111 /* Even if there is no memory, treat as a failure so
1112 * the packet will get dropped.
1117 /* A restart is occurring, check to make sure no new addresses
1118 * are being added as we may be under a takeover attack.
1120 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1121 const struct sctp_association
*asoc
,
1122 struct sctp_chunk
*init
,
1123 sctp_cmd_seq_t
*commands
)
1125 struct sctp_transport
*new_addr
, *addr
;
1126 struct list_head
*pos
, *pos2
;
1129 /* Implementor's Guide - Sectin 5.2.2
1131 * Before responding the endpoint MUST check to see if the
1132 * unexpected INIT adds new addresses to the association. If new
1133 * addresses are added to the association, the endpoint MUST respond
1137 /* Search through all current addresses and make sure
1138 * we aren't adding any new ones.
1143 list_for_each(pos
, &new_asoc
->peer
.transport_addr_list
) {
1144 new_addr
= list_entry(pos
, struct sctp_transport
, transports
);
1146 list_for_each(pos2
, &asoc
->peer
.transport_addr_list
) {
1147 addr
= list_entry(pos2
, struct sctp_transport
,
1149 if (sctp_cmp_addr_exact(&new_addr
->ipaddr
,
1159 /* If a new address was added, ABORT the sender. */
1160 if (!found
&& new_addr
) {
1161 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
, commands
);
1164 /* Return success if all addresses were found. */
1168 /* Populate the verification/tie tags based on overlapping INIT
1171 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1173 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1174 const struct sctp_association
*asoc
)
1176 switch (asoc
->state
) {
1178 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1180 case SCTP_STATE_COOKIE_WAIT
:
1181 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1182 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1183 new_asoc
->c
.peer_ttag
= 0;
1186 case SCTP_STATE_COOKIE_ECHOED
:
1187 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1188 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1189 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1192 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1193 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1196 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1197 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1201 /* Other parameters for the endpoint SHOULD be copied from the
1202 * existing parameters of the association (e.g. number of
1203 * outbound streams) into the INIT ACK and cookie.
1205 new_asoc
->rwnd
= asoc
->rwnd
;
1206 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1207 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1208 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1212 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1215 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1217 * Returns value representing action to be taken. These action values
1218 * correspond to Action/Description values in RFC 2960, Table 2.
1220 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1221 const struct sctp_association
*asoc
)
1223 /* In this case, the peer may have restarted. */
1224 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1225 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1226 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1227 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1230 /* Collision case B. */
1231 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1232 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1233 (0 == asoc
->c
.peer_vtag
))) {
1237 /* Collision case D. */
1238 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1239 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1242 /* Collision case C. */
1243 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1244 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1245 (0 == new_asoc
->c
.my_ttag
) &&
1246 (0 == new_asoc
->c
.peer_ttag
))
1249 /* No match to any of the special cases; discard this packet. */
1253 /* Common helper routine for both duplicate and simulataneous INIT
1256 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1257 const struct sctp_endpoint
*ep
,
1258 const struct sctp_association
*asoc
,
1259 const sctp_subtype_t type
,
1260 void *arg
, sctp_cmd_seq_t
*commands
)
1262 sctp_disposition_t retval
;
1263 struct sctp_chunk
*chunk
= arg
;
1264 struct sctp_chunk
*repl
;
1265 struct sctp_association
*new_asoc
;
1266 struct sctp_chunk
*err_chunk
;
1267 struct sctp_packet
*packet
;
1268 sctp_unrecognized_param_t
*unk_param
;
1272 * An endpoint MUST NOT bundle INIT, INIT ACK or
1273 * SHUTDOWN COMPLETE with any other chunks.
1276 * Furthermore, we require that the receiver of an INIT chunk MUST
1277 * enforce these rules by silently discarding an arriving packet
1278 * with an INIT chunk that is bundled with other chunks.
1280 if (!chunk
->singleton
)
1281 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1283 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1286 if (chunk
->sctp_hdr
->vtag
!= 0)
1287 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1289 /* Make sure that the INIT chunk has a valid length.
1290 * In this case, we generate a protocol violation since we have
1291 * an association established.
1293 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1294 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1296 /* Grab the INIT header. */
1297 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1299 /* Tag the variable length parameters. */
1300 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1302 /* Verify the INIT chunk before processing it. */
1304 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1305 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1307 /* This chunk contains fatal error. It is to be discarded.
1308 * Send an ABORT, with causes if there is any.
1311 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1312 (__u8
*)(err_chunk
->chunk_hdr
) +
1313 sizeof(sctp_chunkhdr_t
),
1314 ntohs(err_chunk
->chunk_hdr
->length
) -
1315 sizeof(sctp_chunkhdr_t
));
1318 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1319 SCTP_PACKET(packet
));
1320 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1321 retval
= SCTP_DISPOSITION_CONSUME
;
1323 retval
= SCTP_DISPOSITION_NOMEM
;
1327 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1333 * Other parameters for the endpoint SHOULD be copied from the
1334 * existing parameters of the association (e.g. number of
1335 * outbound streams) into the INIT ACK and cookie.
1336 * FIXME: We are copying parameters from the endpoint not the
1339 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1343 /* In the outbound INIT ACK the endpoint MUST copy its current
1344 * Verification Tag and Peers Verification tag into a reserved
1345 * place (local tie-tag and per tie-tag) within the state cookie.
1347 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1349 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1351 retval
= SCTP_DISPOSITION_NOMEM
;
1355 /* Make sure no new addresses are being added during the
1356 * restart. Do not do this check for COOKIE-WAIT state,
1357 * since there are no peer addresses to check against.
1358 * Upon return an ABORT will have been sent if needed.
1360 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1361 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1363 retval
= SCTP_DISPOSITION_CONSUME
;
1368 sctp_tietags_populate(new_asoc
, asoc
);
1370 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1372 /* If there are errors need to be reported for unknown parameters,
1373 * make sure to reserve enough room in the INIT ACK for them.
1377 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1378 sizeof(sctp_chunkhdr_t
);
1381 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
1384 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1388 /* If there are errors need to be reported for unknown parameters,
1389 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1393 /* Get the "Unrecognized parameter" parameter(s) out of the
1394 * ERROR chunk generated by sctp_verify_init(). Since the
1395 * error cause code for "unknown parameter" and the
1396 * "Unrecognized parameter" type is the same, we can
1397 * construct the parameters in INIT ACK by copying the
1398 * ERROR causes over.
1400 unk_param
= (sctp_unrecognized_param_t
*)
1401 ((__u8
*)(err_chunk
->chunk_hdr
) +
1402 sizeof(sctp_chunkhdr_t
));
1403 /* Replace the cause code with the "Unrecognized parameter"
1406 sctp_addto_chunk(repl
, len
, unk_param
);
1409 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1410 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1413 * Note: After sending out INIT ACK with the State Cookie parameter,
1414 * "Z" MUST NOT allocate any resources for this new association.
1415 * Otherwise, "Z" will be vulnerable to resource attacks.
1417 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1418 retval
= SCTP_DISPOSITION_CONSUME
;
1422 sctp_chunk_free(err_chunk
);
1425 retval
= SCTP_DISPOSITION_NOMEM
;
1429 sctp_association_free(new_asoc
);
1434 * Handle simultanous INIT.
1435 * This means we started an INIT and then we got an INIT request from
1438 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1439 * This usually indicates an initialization collision, i.e., each
1440 * endpoint is attempting, at about the same time, to establish an
1441 * association with the other endpoint.
1443 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1444 * endpoint MUST respond with an INIT ACK using the same parameters it
1445 * sent in its original INIT chunk (including its Verification Tag,
1446 * unchanged). These original parameters are combined with those from the
1447 * newly received INIT chunk. The endpoint shall also generate a State
1448 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1449 * INIT to calculate the State Cookie.
1451 * After that, the endpoint MUST NOT change its state, the T1-init
1452 * timer shall be left running and the corresponding TCB MUST NOT be
1453 * destroyed. The normal procedures for handling State Cookies when
1454 * a TCB exists will resolve the duplicate INITs to a single association.
1456 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1457 * its Tie-Tags with the Tag information of itself and its peer (see
1458 * section 5.2.2 for a description of the Tie-Tags).
1460 * Verification Tag: Not explicit, but an INIT can not have a valid
1461 * verification tag, so we skip the check.
1464 * (endpoint, asoc, chunk)
1467 * (asoc, reply_msg, msg_up, timers, counters)
1469 * The return value is the disposition of the chunk.
1471 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1472 const struct sctp_association
*asoc
,
1473 const sctp_subtype_t type
,
1475 sctp_cmd_seq_t
*commands
)
1477 /* Call helper to do the real work for both simulataneous and
1478 * duplicate INIT chunk handling.
1480 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1484 * Handle duplicated INIT messages. These are usually delayed
1487 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1488 * COOKIE-ECHOED and COOKIE-WAIT
1490 * Unless otherwise stated, upon reception of an unexpected INIT for
1491 * this association, the endpoint shall generate an INIT ACK with a
1492 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1493 * current Verification Tag and peer's Verification Tag into a reserved
1494 * place within the state cookie. We shall refer to these locations as
1495 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1496 * containing this INIT ACK MUST carry a Verification Tag value equal to
1497 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1498 * MUST contain a new Initiation Tag (randomly generated see Section
1499 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1500 * existing parameters of the association (e.g. number of outbound
1501 * streams) into the INIT ACK and cookie.
1503 * After sending out the INIT ACK, the endpoint shall take no further
1504 * actions, i.e., the existing association, including its current state,
1505 * and the corresponding TCB MUST NOT be changed.
1507 * Note: Only when a TCB exists and the association is not in a COOKIE-
1508 * WAIT state are the Tie-Tags populated. For a normal association INIT
1509 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1510 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1511 * State Cookie are populated as specified in section 5.2.1.
1513 * Verification Tag: Not specified, but an INIT has no way of knowing
1514 * what the verification tag could be, so we ignore it.
1517 * (endpoint, asoc, chunk)
1520 * (asoc, reply_msg, msg_up, timers, counters)
1522 * The return value is the disposition of the chunk.
1524 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1525 const struct sctp_association
*asoc
,
1526 const sctp_subtype_t type
,
1528 sctp_cmd_seq_t
*commands
)
1530 /* Call helper to do the real work for both simulataneous and
1531 * duplicate INIT chunk handling.
1533 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1538 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1541 * A) In this case, the peer may have restarted.
1543 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1544 const struct sctp_association
*asoc
,
1545 struct sctp_chunk
*chunk
,
1546 sctp_cmd_seq_t
*commands
,
1547 struct sctp_association
*new_asoc
)
1549 sctp_init_chunk_t
*peer_init
;
1550 struct sctp_ulpevent
*ev
;
1551 struct sctp_chunk
*repl
;
1552 struct sctp_chunk
*err
;
1553 sctp_disposition_t disposition
;
1555 /* new_asoc is a brand-new association, so these are not yet
1556 * side effects--it is safe to run them here.
1558 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1560 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1561 sctp_source(chunk
), peer_init
,
1565 /* Make sure no new addresses are being added during the
1566 * restart. Though this is a pretty complicated attack
1567 * since you'd have to get inside the cookie.
1569 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1570 return SCTP_DISPOSITION_CONSUME
;
1573 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1574 * the peer has restarted (Action A), it MUST NOT setup a new
1575 * association but instead resend the SHUTDOWN ACK and send an ERROR
1576 * chunk with a "Cookie Received while Shutting Down" error cause to
1579 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1580 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1581 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1583 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1586 err
= sctp_make_op_error(asoc
, chunk
,
1587 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1590 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1593 return SCTP_DISPOSITION_CONSUME
;
1596 /* For now, fail any unsent/unacked data. Consider the optional
1597 * choice of resending of this data.
1599 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1601 /* Update the content of current association. */
1602 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1604 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1608 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1610 /* Report association restart to upper layer. */
1611 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1612 new_asoc
->c
.sinit_num_ostreams
,
1613 new_asoc
->c
.sinit_max_instreams
,
1618 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1619 return SCTP_DISPOSITION_CONSUME
;
1622 sctp_chunk_free(repl
);
1624 return SCTP_DISPOSITION_NOMEM
;
1627 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1630 * B) In this case, both sides may be attempting to start an association
1631 * at about the same time but the peer endpoint started its INIT
1632 * after responding to the local endpoint's INIT
1634 /* This case represents an initialization collision. */
1635 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1636 const struct sctp_association
*asoc
,
1637 struct sctp_chunk
*chunk
,
1638 sctp_cmd_seq_t
*commands
,
1639 struct sctp_association
*new_asoc
)
1641 sctp_init_chunk_t
*peer_init
;
1642 struct sctp_ulpevent
*ev
;
1643 struct sctp_chunk
*repl
;
1645 /* new_asoc is a brand-new association, so these are not yet
1646 * side effects--it is safe to run them here.
1648 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1649 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1650 sctp_source(chunk
), peer_init
,
1654 /* Update the content of current association. */
1655 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1656 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1657 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1658 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1659 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1661 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1665 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1666 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1668 /* RFC 2960 5.1 Normal Establishment of an Association
1670 * D) IMPLEMENTATION NOTE: An implementation may choose to
1671 * send the Communication Up notification to the SCTP user
1672 * upon reception of a valid COOKIE ECHO chunk.
1674 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
, 0,
1675 new_asoc
->c
.sinit_num_ostreams
,
1676 new_asoc
->c
.sinit_max_instreams
,
1681 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1683 /* Sockets API Draft Section 5.3.1.6
1684 * When a peer sends a Adaption Layer Indication parameter , SCTP
1685 * delivers this notification to inform the application that of the
1686 * peers requested adaption layer.
1688 if (asoc
->peer
.adaption_ind
) {
1689 ev
= sctp_ulpevent_make_adaption_indication(asoc
, GFP_ATOMIC
);
1693 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1697 return SCTP_DISPOSITION_CONSUME
;
1700 sctp_chunk_free(repl
);
1702 return SCTP_DISPOSITION_NOMEM
;
1705 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1708 * C) In this case, the local endpoint's cookie has arrived late.
1709 * Before it arrived, the local endpoint sent an INIT and received an
1710 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1711 * but a new tag of its own.
1713 /* This case represents an initialization collision. */
1714 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1715 const struct sctp_association
*asoc
,
1716 struct sctp_chunk
*chunk
,
1717 sctp_cmd_seq_t
*commands
,
1718 struct sctp_association
*new_asoc
)
1720 /* The cookie should be silently discarded.
1721 * The endpoint SHOULD NOT change states and should leave
1722 * any timers running.
1724 return SCTP_DISPOSITION_DISCARD
;
1727 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1731 * D) When both local and remote tags match the endpoint should always
1732 * enter the ESTABLISHED state, if it has not already done so.
1734 /* This case represents an initialization collision. */
1735 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1736 const struct sctp_association
*asoc
,
1737 struct sctp_chunk
*chunk
,
1738 sctp_cmd_seq_t
*commands
,
1739 struct sctp_association
*new_asoc
)
1741 struct sctp_ulpevent
*ev
= NULL
;
1742 struct sctp_chunk
*repl
;
1744 /* Clarification from Implementor's Guide:
1745 * D) When both local and remote tags match the endpoint should
1746 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1747 * It should stop any cookie timer that may be running and send
1751 /* Don't accidentally move back into established state. */
1752 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1753 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1754 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1755 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1756 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1757 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1758 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1761 /* RFC 2960 5.1 Normal Establishment of an Association
1763 * D) IMPLEMENTATION NOTE: An implementation may choose
1764 * to send the Communication Up notification to the
1765 * SCTP user upon reception of a valid COOKIE
1768 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0,
1770 new_asoc
->c
.sinit_num_ostreams
,
1771 new_asoc
->c
.sinit_max_instreams
,
1775 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1778 /* Sockets API Draft Section 5.3.1.6
1779 * When a peer sends a Adaption Layer Indication parameter,
1780 * SCTP delivers this notification to inform the application
1781 * that of the peers requested adaption layer.
1783 if (new_asoc
->peer
.adaption_ind
) {
1784 ev
= sctp_ulpevent_make_adaption_indication(new_asoc
,
1789 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1793 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1795 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1799 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1800 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSMIT
, SCTP_NULL());
1802 return SCTP_DISPOSITION_CONSUME
;
1806 sctp_ulpevent_free(ev
);
1807 return SCTP_DISPOSITION_NOMEM
;
1811 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1812 * chunk was retransmitted and then delayed in the network.
1814 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1816 * Verification Tag: None. Do cookie validation.
1819 * (endpoint, asoc, chunk)
1822 * (asoc, reply_msg, msg_up, timers, counters)
1824 * The return value is the disposition of the chunk.
1826 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1827 const struct sctp_association
*asoc
,
1828 const sctp_subtype_t type
,
1830 sctp_cmd_seq_t
*commands
)
1832 sctp_disposition_t retval
;
1833 struct sctp_chunk
*chunk
= arg
;
1834 struct sctp_association
*new_asoc
;
1837 struct sctp_chunk
*err_chk_p
;
1839 /* Make sure that the chunk has a valid length from the protocol
1840 * perspective. In this case check to make sure we have at least
1841 * enough for the chunk header. Cookie length verification is
1844 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1845 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1848 /* "Decode" the chunk. We have no optional parameters so we
1849 * are in good shape.
1851 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1852 skb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1853 sizeof(sctp_chunkhdr_t
));
1855 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1856 * of a duplicate COOKIE ECHO match the Verification Tags of the
1857 * current association, consider the State Cookie valid even if
1858 * the lifespan is exceeded.
1860 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1864 * If the re-build failed, what is the proper error path
1867 * [We should abort the association. --piggy]
1870 /* FIXME: Several errors are possible. A bad cookie should
1871 * be silently discarded, but think about logging it too.
1874 case -SCTP_IERROR_NOMEM
:
1877 case -SCTP_IERROR_STALE_COOKIE
:
1878 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
1880 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1881 case -SCTP_IERROR_BAD_SIG
:
1883 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1887 /* Compare the tie_tag in cookie with the verification tag of
1888 * current association.
1890 action
= sctp_tietags_compare(new_asoc
, asoc
);
1893 case 'A': /* Association restart. */
1894 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
1898 case 'B': /* Collision case B. */
1899 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
1903 case 'C': /* Collision case C. */
1904 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
1908 case 'D': /* Collision case D. */
1909 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
1913 default: /* Discard packet for all others. */
1914 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1918 /* Delete the tempory new association. */
1919 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1920 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1925 return SCTP_DISPOSITION_NOMEM
;
1929 * Process an ABORT. (SHUTDOWN-PENDING state)
1931 * See sctp_sf_do_9_1_abort().
1933 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
1934 const struct sctp_endpoint
*ep
,
1935 const struct sctp_association
*asoc
,
1936 const sctp_subtype_t type
,
1938 sctp_cmd_seq_t
*commands
)
1940 struct sctp_chunk
*chunk
= arg
;
1942 if (!sctp_vtag_verify_either(chunk
, asoc
))
1943 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1945 /* Make sure that the ABORT chunk has a valid length.
1946 * Since this is an ABORT chunk, we have to discard it
1947 * because of the following text:
1948 * RFC 2960, Section 3.3.7
1949 * If an endpoint receives an ABORT with a format error or for an
1950 * association that doesn't exist, it MUST silently discard it.
1951 * Becasue the length is "invalid", we can't really discard just
1952 * as we do not know its true length. So, to be safe, discard the
1955 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
1956 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1958 /* Stop the T5-shutdown guard timer. */
1959 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1960 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
1962 return sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
1966 * Process an ABORT. (SHUTDOWN-SENT state)
1968 * See sctp_sf_do_9_1_abort().
1970 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
1971 const struct sctp_association
*asoc
,
1972 const sctp_subtype_t type
,
1974 sctp_cmd_seq_t
*commands
)
1976 struct sctp_chunk
*chunk
= arg
;
1978 if (!sctp_vtag_verify_either(chunk
, asoc
))
1979 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1981 /* Make sure that the ABORT chunk has a valid length.
1982 * Since this is an ABORT chunk, we have to discard it
1983 * because of the following text:
1984 * RFC 2960, Section 3.3.7
1985 * If an endpoint receives an ABORT with a format error or for an
1986 * association that doesn't exist, it MUST silently discard it.
1987 * Becasue the length is "invalid", we can't really discard just
1988 * as we do not know its true length. So, to be safe, discard the
1991 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
1992 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1994 /* Stop the T2-shutdown timer. */
1995 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1996 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
1998 /* Stop the T5-shutdown guard timer. */
1999 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2000 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2002 return sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2006 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2008 * See sctp_sf_do_9_1_abort().
2010 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2011 const struct sctp_endpoint
*ep
,
2012 const struct sctp_association
*asoc
,
2013 const sctp_subtype_t type
,
2015 sctp_cmd_seq_t
*commands
)
2017 /* The same T2 timer, so we should be able to use
2018 * common function with the SHUTDOWN-SENT state.
2020 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2024 * Handle an Error received in COOKIE_ECHOED state.
2026 * Only handle the error type of stale COOKIE Error, the other errors will
2030 * (endpoint, asoc, chunk)
2033 * (asoc, reply_msg, msg_up, timers, counters)
2035 * The return value is the disposition of the chunk.
2037 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2038 const struct sctp_association
*asoc
,
2039 const sctp_subtype_t type
,
2041 sctp_cmd_seq_t
*commands
)
2043 struct sctp_chunk
*chunk
= arg
;
2046 if (!sctp_vtag_verify(chunk
, asoc
))
2047 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2049 /* Make sure that the ERROR chunk has a valid length.
2050 * The parameter walking depends on this as well.
2052 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2053 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2056 /* Process the error here */
2057 /* FUTURE FIXME: When PR-SCTP related and other optional
2058 * parms are emitted, this will have to change to handle multiple
2061 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2062 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2063 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2067 /* It is possible to have malformed error causes, and that
2068 * will cause us to end the walk early. However, since
2069 * we are discarding the packet, there should be no adverse
2072 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2076 * Handle a Stale COOKIE Error
2078 * Section: 5.2.6 Handle Stale COOKIE Error
2079 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2080 * one of the following three alternatives.
2082 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2083 * Preservative parameter requesting an extension to the lifetime of
2084 * the State Cookie. When calculating the time extension, an
2085 * implementation SHOULD use the RTT information measured based on the
2086 * previous COOKIE ECHO / ERROR exchange, and should add no more
2087 * than 1 second beyond the measured RTT, due to long State Cookie
2088 * lifetimes making the endpoint more subject to a replay attack.
2090 * Verification Tag: Not explicit, but safe to ignore.
2093 * (endpoint, asoc, chunk)
2096 * (asoc, reply_msg, msg_up, timers, counters)
2098 * The return value is the disposition of the chunk.
2100 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2101 const struct sctp_association
*asoc
,
2102 const sctp_subtype_t type
,
2104 sctp_cmd_seq_t
*commands
)
2106 struct sctp_chunk
*chunk
= arg
;
2108 sctp_cookie_preserve_param_t bht
;
2110 struct sctp_chunk
*reply
;
2111 struct sctp_bind_addr
*bp
;
2112 int attempts
= asoc
->init_err_counter
+ 1;
2114 if (attempts
>= asoc
->max_init_attempts
) {
2115 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2116 SCTP_U32(SCTP_ERROR_STALE_COOKIE
));
2117 return SCTP_DISPOSITION_DELETE_TCB
;
2120 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2122 /* When calculating the time extension, an implementation
2123 * SHOULD use the RTT information measured based on the
2124 * previous COOKIE ECHO / ERROR exchange, and should add no
2125 * more than 1 second beyond the measured RTT, due to long
2126 * State Cookie lifetimes making the endpoint more subject to
2128 * Measure of Staleness's unit is usec. (1/1000000 sec)
2129 * Suggested Cookie Life-span Increment's unit is msec.
2131 * In general, if you use the suggested cookie life, the value
2132 * found in the field of measure of staleness should be doubled
2133 * to give ample time to retransmit the new cookie and thus
2134 * yield a higher probability of success on the reattempt.
2136 stale
= ntohl(*(suseconds_t
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2137 stale
= (stale
* 2) / 1000;
2139 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2140 bht
.param_hdr
.length
= htons(sizeof(bht
));
2141 bht
.lifespan_increment
= htonl(stale
);
2143 /* Build that new INIT chunk. */
2144 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2145 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2149 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2151 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2152 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2154 /* Stop pending T3-rtx and heartbeat timers */
2155 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2156 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2158 /* Delete non-primary peer ip addresses since we are transitioning
2159 * back to the COOKIE-WAIT state
2161 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2163 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2166 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
,
2167 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2169 /* Cast away the const modifier, as we want to just
2170 * rerun it through as a sideffect.
2172 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2174 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2175 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2176 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2177 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2178 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2179 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2181 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2183 return SCTP_DISPOSITION_CONSUME
;
2186 return SCTP_DISPOSITION_NOMEM
;
2193 * After checking the Verification Tag, the receiving endpoint shall
2194 * remove the association from its record, and shall report the
2195 * termination to its upper layer.
2197 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2198 * B) Rules for packet carrying ABORT:
2200 * - The endpoint shall always fill in the Verification Tag field of the
2201 * outbound packet with the destination endpoint's tag value if it
2204 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2205 * MUST follow the procedure described in Section 8.4.
2207 * - The receiver MUST accept the packet if the Verification Tag
2208 * matches either its own tag, OR the tag of its peer. Otherwise, the
2209 * receiver MUST silently discard the packet and take no further
2213 * (endpoint, asoc, chunk)
2216 * (asoc, reply_msg, msg_up, timers, counters)
2218 * The return value is the disposition of the chunk.
2220 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2221 const struct sctp_association
*asoc
,
2222 const sctp_subtype_t type
,
2224 sctp_cmd_seq_t
*commands
)
2226 struct sctp_chunk
*chunk
= arg
;
2228 __u16 error
= SCTP_ERROR_NO_ERROR
;
2230 if (!sctp_vtag_verify_either(chunk
, asoc
))
2231 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2233 /* Make sure that the ABORT chunk has a valid length.
2234 * Since this is an ABORT chunk, we have to discard it
2235 * because of the following text:
2236 * RFC 2960, Section 3.3.7
2237 * If an endpoint receives an ABORT with a format error or for an
2238 * association that doesn't exist, it MUST silently discard it.
2239 * Becasue the length is "invalid", we can't really discard just
2240 * as we do not know its true length. So, to be safe, discard the
2243 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2244 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2246 /* See if we have an error cause code in the chunk. */
2247 len
= ntohs(chunk
->chunk_hdr
->length
);
2248 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2249 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2251 /* ASSOC_FAILED will DELETE_TCB. */
2252 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_U32(error
));
2253 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2254 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2256 return SCTP_DISPOSITION_ABORT
;
2260 * Process an ABORT. (COOKIE-WAIT state)
2262 * See sctp_sf_do_9_1_abort() above.
2264 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2265 const struct sctp_association
*asoc
,
2266 const sctp_subtype_t type
,
2268 sctp_cmd_seq_t
*commands
)
2270 struct sctp_chunk
*chunk
= arg
;
2272 __u16 error
= SCTP_ERROR_NO_ERROR
;
2274 if (!sctp_vtag_verify_either(chunk
, asoc
))
2275 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2277 /* Make sure that the ABORT chunk has a valid length.
2278 * Since this is an ABORT chunk, we have to discard it
2279 * because of the following text:
2280 * RFC 2960, Section 3.3.7
2281 * If an endpoint receives an ABORT with a format error or for an
2282 * association that doesn't exist, it MUST silently discard it.
2283 * Becasue the length is "invalid", we can't really discard just
2284 * as we do not know its true length. So, to be safe, discard the
2287 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2288 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2290 /* See if we have an error cause code in the chunk. */
2291 len
= ntohs(chunk
->chunk_hdr
->length
);
2292 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2293 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2295 return sctp_stop_t1_and_abort(commands
, error
, asoc
, chunk
->transport
);
2299 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2301 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2302 const struct sctp_association
*asoc
,
2303 const sctp_subtype_t type
,
2305 sctp_cmd_seq_t
*commands
)
2307 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
, asoc
,
2308 (struct sctp_transport
*)arg
);
2312 * Process an ABORT. (COOKIE-ECHOED state)
2314 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2315 const struct sctp_association
*asoc
,
2316 const sctp_subtype_t type
,
2318 sctp_cmd_seq_t
*commands
)
2320 /* There is a single T1 timer, so we should be able to use
2321 * common function with the COOKIE-WAIT state.
2323 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2327 * Stop T1 timer and abort association with "INIT failed".
2329 * This is common code called by several sctp_sf_*_abort() functions above.
2331 sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2333 const struct sctp_association
*asoc
,
2334 struct sctp_transport
*transport
)
2336 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2337 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2338 SCTP_STATE(SCTP_STATE_CLOSED
));
2339 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2340 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2341 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2342 /* CMD_INIT_FAILED will DELETE_TCB. */
2343 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2345 return SCTP_DISPOSITION_ABORT
;
2349 * sctp_sf_do_9_2_shut
2352 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2353 * - enter the SHUTDOWN-RECEIVED state,
2355 * - stop accepting new data from its SCTP user
2357 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2358 * that all its outstanding DATA chunks have been received by the
2361 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2362 * send a SHUTDOWN in response to a ULP request. And should discard
2363 * subsequent SHUTDOWN chunks.
2365 * If there are still outstanding DATA chunks left, the SHUTDOWN
2366 * receiver shall continue to follow normal data transmission
2367 * procedures defined in Section 6 until all outstanding DATA chunks
2368 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2369 * new data from its SCTP user.
2371 * Verification Tag: 8.5 Verification Tag [Normal verification]
2374 * (endpoint, asoc, chunk)
2377 * (asoc, reply_msg, msg_up, timers, counters)
2379 * The return value is the disposition of the chunk.
2381 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2382 const struct sctp_association
*asoc
,
2383 const sctp_subtype_t type
,
2385 sctp_cmd_seq_t
*commands
)
2387 struct sctp_chunk
*chunk
= arg
;
2388 sctp_shutdownhdr_t
*sdh
;
2389 sctp_disposition_t disposition
;
2390 struct sctp_ulpevent
*ev
;
2392 if (!sctp_vtag_verify(chunk
, asoc
))
2393 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2395 /* Make sure that the SHUTDOWN chunk has a valid length. */
2396 if (!sctp_chunk_length_valid(chunk
,
2397 sizeof(struct sctp_shutdown_chunk_t
)))
2398 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2401 /* Convert the elaborate header. */
2402 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2403 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2404 chunk
->subh
.shutdown_hdr
= sdh
;
2406 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2407 * - enter the SHUTDOWN-RECEIVED state,
2408 * - stop accepting new data from its SCTP user
2410 * [This is implicit in the new state.]
2412 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2413 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2414 disposition
= SCTP_DISPOSITION_CONSUME
;
2416 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2417 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2421 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2424 /* - verify, by checking the Cumulative TSN Ack field of the
2425 * chunk, that all its outstanding DATA chunks have been
2426 * received by the SHUTDOWN sender.
2428 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2429 SCTP_U32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2431 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2432 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2433 * inform the application that it should cease sending data.
2435 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2437 disposition
= SCTP_DISPOSITION_NOMEM
;
2440 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2447 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2448 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2449 * transport addresses (either in the IP addresses or in the INIT chunk)
2450 * that belong to this association, it should discard the INIT chunk and
2451 * retransmit the SHUTDOWN ACK chunk.
2453 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2454 const struct sctp_association
*asoc
,
2455 const sctp_subtype_t type
,
2457 sctp_cmd_seq_t
*commands
)
2459 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2460 struct sctp_chunk
*reply
;
2462 /* Since we are not going to really process this INIT, there
2463 * is no point in verifying chunk boundries. Just generate
2466 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2470 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2471 * the T2-SHUTDOWN timer.
2473 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2475 /* and restart the T2-shutdown timer. */
2476 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2477 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2479 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2481 return SCTP_DISPOSITION_CONSUME
;
2483 return SCTP_DISPOSITION_NOMEM
;
2487 * sctp_sf_do_ecn_cwr
2489 * Section: Appendix A: Explicit Congestion Notification
2493 * RFC 2481 details a specific bit for a sender to send in the header of
2494 * its next outbound TCP segment to indicate to its peer that it has
2495 * reduced its congestion window. This is termed the CWR bit. For
2496 * SCTP the same indication is made by including the CWR chunk.
2497 * This chunk contains one data element, i.e. the TSN number that
2498 * was sent in the ECNE chunk. This element represents the lowest
2499 * TSN number in the datagram that was originally marked with the
2502 * Verification Tag: 8.5 Verification Tag [Normal verification]
2504 * (endpoint, asoc, chunk)
2507 * (asoc, reply_msg, msg_up, timers, counters)
2509 * The return value is the disposition of the chunk.
2511 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2512 const struct sctp_association
*asoc
,
2513 const sctp_subtype_t type
,
2515 sctp_cmd_seq_t
*commands
)
2518 struct sctp_chunk
*chunk
= arg
;
2520 if (!sctp_vtag_verify(chunk
, asoc
))
2521 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2523 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2524 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2527 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2528 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2530 cwr
->lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2532 /* Does this CWR ack the last sent congestion notification? */
2533 if (TSN_lte(asoc
->last_ecne_tsn
, cwr
->lowest_tsn
)) {
2534 /* Stop sending ECNE. */
2535 sctp_add_cmd_sf(commands
,
2537 SCTP_U32(cwr
->lowest_tsn
));
2539 return SCTP_DISPOSITION_CONSUME
;
2545 * Section: Appendix A: Explicit Congestion Notification
2549 * RFC 2481 details a specific bit for a receiver to send back in its
2550 * TCP acknowledgements to notify the sender of the Congestion
2551 * Experienced (CE) bit having arrived from the network. For SCTP this
2552 * same indication is made by including the ECNE chunk. This chunk
2553 * contains one data element, i.e. the lowest TSN associated with the IP
2554 * datagram marked with the CE bit.....
2556 * Verification Tag: 8.5 Verification Tag [Normal verification]
2558 * (endpoint, asoc, chunk)
2561 * (asoc, reply_msg, msg_up, timers, counters)
2563 * The return value is the disposition of the chunk.
2565 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2566 const struct sctp_association
*asoc
,
2567 const sctp_subtype_t type
,
2569 sctp_cmd_seq_t
*commands
)
2571 sctp_ecnehdr_t
*ecne
;
2572 struct sctp_chunk
*chunk
= arg
;
2574 if (!sctp_vtag_verify(chunk
, asoc
))
2575 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2577 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2578 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2581 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2582 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2584 /* If this is a newer ECNE than the last CWR packet we sent out */
2585 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2586 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2588 return SCTP_DISPOSITION_CONSUME
;
2592 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2594 * The SCTP endpoint MUST always acknowledge the reception of each valid
2597 * The guidelines on delayed acknowledgement algorithm specified in
2598 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2599 * acknowledgement SHOULD be generated for at least every second packet
2600 * (not every second DATA chunk) received, and SHOULD be generated within
2601 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2602 * situations it may be beneficial for an SCTP transmitter to be more
2603 * conservative than the algorithms detailed in this document allow.
2604 * However, an SCTP transmitter MUST NOT be more aggressive than the
2605 * following algorithms allow.
2607 * A SCTP receiver MUST NOT generate more than one SACK for every
2608 * incoming packet, other than to update the offered window as the
2609 * receiving application consumes new data.
2611 * Verification Tag: 8.5 Verification Tag [Normal verification]
2614 * (endpoint, asoc, chunk)
2617 * (asoc, reply_msg, msg_up, timers, counters)
2619 * The return value is the disposition of the chunk.
2621 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2622 const struct sctp_association
*asoc
,
2623 const sctp_subtype_t type
,
2625 sctp_cmd_seq_t
*commands
)
2627 struct sctp_chunk
*chunk
= arg
;
2630 if (!sctp_vtag_verify(chunk
, asoc
)) {
2631 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2633 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2636 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2637 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2640 error
= sctp_eat_data(asoc
, chunk
, commands
);
2642 case SCTP_IERROR_NO_ERROR
:
2644 case SCTP_IERROR_HIGH_TSN
:
2645 case SCTP_IERROR_BAD_STREAM
:
2646 goto discard_noforce
;
2647 case SCTP_IERROR_DUP_TSN
:
2648 case SCTP_IERROR_IGNORE_TSN
:
2650 case SCTP_IERROR_NO_DATA
:
2656 if (asoc
->autoclose
) {
2657 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2658 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2661 /* If this is the last chunk in a packet, we need to count it
2662 * toward sack generation. Note that we need to SACK every
2663 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2664 * THEM. We elect to NOT generate SACK's if the chunk fails
2665 * the verification tag test.
2667 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2669 * The SCTP endpoint MUST always acknowledge the reception of
2670 * each valid DATA chunk.
2672 * The guidelines on delayed acknowledgement algorithm
2673 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2674 * Specifically, an acknowledgement SHOULD be generated for at
2675 * least every second packet (not every second DATA chunk)
2676 * received, and SHOULD be generated within 200 ms of the
2677 * arrival of any unacknowledged DATA chunk. In some
2678 * situations it may be beneficial for an SCTP transmitter to
2679 * be more conservative than the algorithms detailed in this
2680 * document allow. However, an SCTP transmitter MUST NOT be
2681 * more aggressive than the following algorithms allow.
2683 if (chunk
->end_of_packet
) {
2684 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2686 /* Start the SACK timer. */
2687 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2688 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
2691 return SCTP_DISPOSITION_CONSUME
;
2694 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2696 * When a packet arrives with duplicate DATA chunk(s) and with
2697 * no new DATA chunk(s), the endpoint MUST immediately send a
2698 * SACK with no delay. If a packet arrives with duplicate
2699 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2700 * MAY immediately send a SACK. Normally receipt of duplicate
2701 * DATA chunks will occur when the original SACK chunk was lost
2702 * and the peer's RTO has expired. The duplicate TSN number(s)
2703 * SHOULD be reported in the SACK as duplicate.
2705 /* In our case, we split the MAY SACK advice up whether or not
2706 * the last chunk is a duplicate.'
2708 if (chunk
->end_of_packet
)
2709 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2710 return SCTP_DISPOSITION_DISCARD
;
2713 if (chunk
->end_of_packet
) {
2714 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2716 /* Start the SACK timer. */
2717 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2718 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
2720 return SCTP_DISPOSITION_DISCARD
;
2722 return SCTP_DISPOSITION_CONSUME
;
2727 * sctp_sf_eat_data_fast_4_4
2730 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2731 * DATA chunks without delay.
2733 * Verification Tag: 8.5 Verification Tag [Normal verification]
2735 * (endpoint, asoc, chunk)
2738 * (asoc, reply_msg, msg_up, timers, counters)
2740 * The return value is the disposition of the chunk.
2742 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2743 const struct sctp_association
*asoc
,
2744 const sctp_subtype_t type
,
2746 sctp_cmd_seq_t
*commands
)
2748 struct sctp_chunk
*chunk
= arg
;
2751 if (!sctp_vtag_verify(chunk
, asoc
)) {
2752 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2754 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2757 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2758 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2761 error
= sctp_eat_data(asoc
, chunk
, commands
);
2763 case SCTP_IERROR_NO_ERROR
:
2764 case SCTP_IERROR_HIGH_TSN
:
2765 case SCTP_IERROR_DUP_TSN
:
2766 case SCTP_IERROR_IGNORE_TSN
:
2767 case SCTP_IERROR_BAD_STREAM
:
2769 case SCTP_IERROR_NO_DATA
:
2775 /* Go a head and force a SACK, since we are shutting down. */
2777 /* Implementor's Guide.
2779 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2780 * respond to each received packet containing one or more DATA chunk(s)
2781 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2783 if (chunk
->end_of_packet
) {
2784 /* We must delay the chunk creation since the cumulative
2785 * TSN has not been updated yet.
2787 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
2788 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2789 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2790 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2794 return SCTP_DISPOSITION_CONSUME
;
2798 * Section: 6.2 Processing a Received SACK
2799 * D) Any time a SACK arrives, the endpoint performs the following:
2801 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2802 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2803 * increasing, a SACK whose Cumulative TSN Ack is less than the
2804 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2806 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2807 * of bytes still outstanding after processing the Cumulative TSN Ack
2808 * and the Gap Ack Blocks.
2810 * iii) If the SACK is missing a TSN that was previously
2811 * acknowledged via a Gap Ack Block (e.g., the data receiver
2812 * reneged on the data), then mark the corresponding DATA chunk
2813 * as available for retransmit: Mark it as missing for fast
2814 * retransmit as described in Section 7.2.4 and if no retransmit
2815 * timer is running for the destination address to which the DATA
2816 * chunk was originally transmitted, then T3-rtx is started for
2817 * that destination address.
2819 * Verification Tag: 8.5 Verification Tag [Normal verification]
2822 * (endpoint, asoc, chunk)
2825 * (asoc, reply_msg, msg_up, timers, counters)
2827 * The return value is the disposition of the chunk.
2829 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
2830 const struct sctp_association
*asoc
,
2831 const sctp_subtype_t type
,
2833 sctp_cmd_seq_t
*commands
)
2835 struct sctp_chunk
*chunk
= arg
;
2836 sctp_sackhdr_t
*sackh
;
2839 if (!sctp_vtag_verify(chunk
, asoc
))
2840 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2842 /* Make sure that the SACK chunk has a valid length. */
2843 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
2844 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2847 /* Pull the SACK chunk from the data buffer */
2848 sackh
= sctp_sm_pull_sack(chunk
);
2849 /* Was this a bogus SACK? */
2851 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2852 chunk
->subh
.sack_hdr
= sackh
;
2853 ctsn
= ntohl(sackh
->cum_tsn_ack
);
2855 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2856 * Ack Point, then drop the SACK. Since Cumulative TSN
2857 * Ack is monotonically increasing, a SACK whose
2858 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2859 * Point indicates an out-of-order SACK.
2861 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2862 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2863 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2864 return SCTP_DISPOSITION_DISCARD
;
2867 /* Return this SACK for further processing. */
2868 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
2870 /* Note: We do the rest of the work on the PROCESS_SACK
2873 return SCTP_DISPOSITION_CONSUME
;
2877 * Generate an ABORT in response to a packet.
2879 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
2881 * 8) The receiver should respond to the sender of the OOTB packet with
2882 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2883 * MUST fill in the Verification Tag field of the outbound packet
2884 * with the value found in the Verification Tag field of the OOTB
2885 * packet and set the T-bit in the Chunk Flags to indicate that the
2886 * Verification Tag is reflected. After sending this ABORT, the
2887 * receiver of the OOTB packet shall discard the OOTB packet and take
2888 * no further action.
2892 * The return value is the disposition of the chunk.
2894 sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
2895 const struct sctp_association
*asoc
,
2896 const sctp_subtype_t type
,
2898 sctp_cmd_seq_t
*commands
)
2900 struct sctp_packet
*packet
= NULL
;
2901 struct sctp_chunk
*chunk
= arg
;
2902 struct sctp_chunk
*abort
;
2904 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
2907 /* Make an ABORT. The T bit will be set if the asoc
2910 abort
= sctp_make_abort(asoc
, chunk
, 0);
2912 sctp_ootb_pkt_free(packet
);
2913 return SCTP_DISPOSITION_NOMEM
;
2916 /* Reflect vtag if T-Bit is set */
2917 if (sctp_test_T_bit(abort
))
2918 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
2920 /* Set the skb to the belonging sock for accounting. */
2921 abort
->skb
->sk
= ep
->base
.sk
;
2923 sctp_packet_append_chunk(packet
, abort
);
2925 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
2926 SCTP_PACKET(packet
));
2928 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
2930 return SCTP_DISPOSITION_CONSUME
;
2933 return SCTP_DISPOSITION_NOMEM
;
2937 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2938 * event as ULP notification for each cause included in the chunk.
2940 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2942 * The return value is the disposition of the chunk.
2944 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
2945 const struct sctp_association
*asoc
,
2946 const sctp_subtype_t type
,
2948 sctp_cmd_seq_t
*commands
)
2950 struct sctp_chunk
*chunk
= arg
;
2951 struct sctp_ulpevent
*ev
;
2953 if (!sctp_vtag_verify(chunk
, asoc
))
2954 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2956 /* Make sure that the ERROR chunk has a valid length. */
2957 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2958 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2961 while (chunk
->chunk_end
> chunk
->skb
->data
) {
2962 ev
= sctp_ulpevent_make_remote_error(asoc
, chunk
, 0,
2967 if (!sctp_add_cmd(commands
, SCTP_CMD_EVENT_ULP
,
2968 SCTP_ULPEVENT(ev
))) {
2969 sctp_ulpevent_free(ev
);
2973 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
2976 return SCTP_DISPOSITION_CONSUME
;
2979 return SCTP_DISPOSITION_NOMEM
;
2983 * Process an inbound SHUTDOWN ACK.
2986 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2987 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2988 * peer, and remove all record of the association.
2990 * The return value is the disposition.
2992 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
2993 const struct sctp_association
*asoc
,
2994 const sctp_subtype_t type
,
2996 sctp_cmd_seq_t
*commands
)
2998 struct sctp_chunk
*chunk
= arg
;
2999 struct sctp_chunk
*reply
;
3000 struct sctp_ulpevent
*ev
;
3002 if (!sctp_vtag_verify(chunk
, asoc
))
3003 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3005 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3006 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3007 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3010 /* 10.2 H) SHUTDOWN COMPLETE notification
3012 * When SCTP completes the shutdown procedures (section 9.2) this
3013 * notification is passed to the upper layer.
3015 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3016 0, 0, 0, GFP_ATOMIC
);
3020 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3022 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3023 * stop the T2-shutdown timer,
3025 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3026 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3028 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3029 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3031 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3032 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3036 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3037 SCTP_STATE(SCTP_STATE_CLOSED
));
3038 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3039 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3040 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3042 /* ...and remove all record of the association. */
3043 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3044 return SCTP_DISPOSITION_DELETE_TCB
;
3047 return SCTP_DISPOSITION_NOMEM
;
3051 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3053 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3054 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3055 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3056 * packet must fill in the Verification Tag field of the outbound
3057 * packet with the Verification Tag received in the SHUTDOWN ACK and
3058 * set the T-bit in the Chunk Flags to indicate that the Verification
3061 * 8) The receiver should respond to the sender of the OOTB packet with
3062 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3063 * MUST fill in the Verification Tag field of the outbound packet
3064 * with the value found in the Verification Tag field of the OOTB
3065 * packet and set the T-bit in the Chunk Flags to indicate that the
3066 * Verification Tag is reflected. After sending this ABORT, the
3067 * receiver of the OOTB packet shall discard the OOTB packet and take
3068 * no further action.
3070 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3071 const struct sctp_association
*asoc
,
3072 const sctp_subtype_t type
,
3074 sctp_cmd_seq_t
*commands
)
3076 struct sctp_chunk
*chunk
= arg
;
3077 struct sk_buff
*skb
= chunk
->skb
;
3078 sctp_chunkhdr_t
*ch
;
3080 int ootb_shut_ack
= 0;
3082 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3084 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3086 /* Break out if chunk length is less then minimal. */
3087 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3090 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3092 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3095 /* RFC 2960, Section 3.3.7
3096 * Moreover, under any circumstances, an endpoint that
3097 * receives an ABORT MUST NOT respond to that ABORT by
3098 * sending an ABORT of its own.
3100 if (SCTP_CID_ABORT
== ch
->type
)
3101 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3103 ch
= (sctp_chunkhdr_t
*) ch_end
;
3104 } while (ch_end
< skb
->tail
);
3107 sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3109 sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3111 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3115 * Handle an "Out of the blue" SHUTDOWN ACK.
3117 * Section: 8.4 5, sctpimpguide 2.41.
3119 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3120 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3121 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3122 * packet must fill in the Verification Tag field of the outbound
3123 * packet with the Verification Tag received in the SHUTDOWN ACK and
3124 * set the T-bit in the Chunk Flags to indicate that the Verification
3128 * (endpoint, asoc, type, arg, commands)
3131 * (sctp_disposition_t)
3133 * The return value is the disposition of the chunk.
3135 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3136 const struct sctp_association
*asoc
,
3137 const sctp_subtype_t type
,
3139 sctp_cmd_seq_t
*commands
)
3141 struct sctp_packet
*packet
= NULL
;
3142 struct sctp_chunk
*chunk
= arg
;
3143 struct sctp_chunk
*shut
;
3145 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3148 /* Make an SHUTDOWN_COMPLETE.
3149 * The T bit will be set if the asoc is NULL.
3151 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3153 sctp_ootb_pkt_free(packet
);
3154 return SCTP_DISPOSITION_NOMEM
;
3157 /* Reflect vtag if T-Bit is set */
3158 if (sctp_test_T_bit(shut
))
3159 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3161 /* Set the skb to the belonging sock for accounting. */
3162 shut
->skb
->sk
= ep
->base
.sk
;
3164 sctp_packet_append_chunk(packet
, shut
);
3166 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3167 SCTP_PACKET(packet
));
3169 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3171 /* If the chunk length is invalid, we don't want to process
3172 * the reset of the packet.
3174 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3175 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3177 return SCTP_DISPOSITION_CONSUME
;
3180 return SCTP_DISPOSITION_NOMEM
;
3184 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3186 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3187 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3188 * procedures in section 8.4 SHOULD be followed, in other words it
3189 * should be treated as an Out Of The Blue packet.
3190 * [This means that we do NOT check the Verification Tag on these
3194 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3195 const struct sctp_association
*asoc
,
3196 const sctp_subtype_t type
,
3198 sctp_cmd_seq_t
*commands
)
3200 /* Although we do have an association in this case, it corresponds
3201 * to a restarted association. So the packet is treated as an OOTB
3202 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3203 * called with a NULL association.
3205 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3208 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3209 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3210 const struct sctp_association
*asoc
,
3211 const sctp_subtype_t type
, void *arg
,
3212 sctp_cmd_seq_t
*commands
)
3214 struct sctp_chunk
*chunk
= arg
;
3215 struct sctp_chunk
*asconf_ack
= NULL
;
3216 sctp_addiphdr_t
*hdr
;
3219 if (!sctp_vtag_verify(chunk
, asoc
)) {
3220 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3222 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3225 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3226 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3227 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3230 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3231 serial
= ntohl(hdr
->serial
);
3233 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3234 * the endpoint stored in a new association variable
3235 * 'Peer-Serial-Number'.
3237 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3238 /* ADDIP 4.2 C2) If the value found in the serial number is
3239 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3242 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3245 return SCTP_DISPOSITION_NOMEM
;
3246 } else if (serial
== asoc
->peer
.addip_serial
) {
3247 /* ADDIP 4.2 C3) If the value found in the serial number is
3248 * equal to the value stored in the 'Peer-Serial-Number'
3249 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3250 * to save the last ASCONF-ACK for some predetermined period of
3251 * time and instead of re-processing the ASCONF (with the same
3252 * serial number) it may just re-transmit the ASCONF-ACK.
3254 if (asoc
->addip_last_asconf_ack
)
3255 asconf_ack
= asoc
->addip_last_asconf_ack
;
3257 return SCTP_DISPOSITION_DISCARD
;
3259 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3260 * it must be either a stale packet or from an attacker.
3262 return SCTP_DISPOSITION_DISCARD
;
3265 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3266 * back to the source address contained in the IP header of the ASCONF
3267 * being responded to.
3269 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3271 return SCTP_DISPOSITION_CONSUME
;
3275 * ADDIP Section 4.3 General rules for address manipulation
3276 * When building TLV parameters for the ASCONF Chunk that will add or
3277 * delete IP addresses the D0 to D13 rules should be applied:
3279 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3280 const struct sctp_association
*asoc
,
3281 const sctp_subtype_t type
, void *arg
,
3282 sctp_cmd_seq_t
*commands
)
3284 struct sctp_chunk
*asconf_ack
= arg
;
3285 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3286 struct sctp_chunk
*abort
;
3287 sctp_addiphdr_t
*addip_hdr
;
3288 __u32 sent_serial
, rcvd_serial
;
3290 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3291 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3293 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3296 /* Make sure that the ADDIP chunk has a valid length. */
3297 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3298 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3301 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3302 rcvd_serial
= ntohl(addip_hdr
->serial
);
3305 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3306 sent_serial
= ntohl(addip_hdr
->serial
);
3308 sent_serial
= asoc
->addip_serial
- 1;
3311 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3312 * equal to the next serial number to be used but no ASCONF chunk is
3313 * outstanding the endpoint MUST ABORT the association. Note that a
3314 * sequence number is greater than if it is no more than 2^^31-1
3315 * larger than the current sequence number (using serial arithmetic).
3317 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3318 !(asoc
->addip_last_asconf
)) {
3319 abort
= sctp_make_abort(asoc
, asconf_ack
,
3320 sizeof(sctp_errhdr_t
));
3322 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, NULL
, 0);
3323 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3326 /* We are going to ABORT, so we might as well stop
3327 * processing the rest of the chunks in the packet.
3329 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3330 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3331 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3332 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3333 SCTP_U32(SCTP_ERROR_ASCONF_ACK
));
3334 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3335 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3336 return SCTP_DISPOSITION_ABORT
;
3339 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3340 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3341 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3343 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3345 return SCTP_DISPOSITION_CONSUME
;
3347 abort
= sctp_make_abort(asoc
, asconf_ack
,
3348 sizeof(sctp_errhdr_t
));
3350 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, NULL
, 0);
3351 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3354 /* We are going to ABORT, so we might as well stop
3355 * processing the rest of the chunks in the packet.
3357 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3358 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3359 SCTP_U32(SCTP_ERROR_ASCONF_ACK
));
3360 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3361 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3362 return SCTP_DISPOSITION_ABORT
;
3365 return SCTP_DISPOSITION_DISCARD
;
3369 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3371 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3372 * its cumulative TSN point to the value carried in the FORWARD TSN
3373 * chunk, and then MUST further advance its cumulative TSN point locally
3375 * After the above processing, the data receiver MUST stop reporting any
3376 * missing TSNs earlier than or equal to the new cumulative TSN point.
3378 * Verification Tag: 8.5 Verification Tag [Normal verification]
3380 * The return value is the disposition of the chunk.
3382 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3383 const struct sctp_association
*asoc
,
3384 const sctp_subtype_t type
,
3386 sctp_cmd_seq_t
*commands
)
3388 struct sctp_chunk
*chunk
= arg
;
3389 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3393 if (!sctp_vtag_verify(chunk
, asoc
)) {
3394 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3396 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3399 /* Make sure that the FORWARD_TSN chunk has valid length. */
3400 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3401 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3404 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3405 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3406 len
= ntohs(chunk
->chunk_hdr
->length
);
3407 len
-= sizeof(struct sctp_chunkhdr
);
3408 skb_pull(chunk
->skb
, len
);
3410 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3411 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__
, tsn
);
3413 /* The TSN is too high--silently discard the chunk and count on it
3414 * getting retransmitted later.
3416 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3417 goto discard_noforce
;
3419 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3420 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3421 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3424 /* Count this as receiving DATA. */
3425 if (asoc
->autoclose
) {
3426 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3427 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3430 /* FIXME: For now send a SACK, but DATA processing may
3433 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3434 /* Start the SACK timer. */
3435 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3436 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
3438 return SCTP_DISPOSITION_CONSUME
;
3441 return SCTP_DISPOSITION_DISCARD
;
3444 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3445 const struct sctp_endpoint
*ep
,
3446 const struct sctp_association
*asoc
,
3447 const sctp_subtype_t type
,
3449 sctp_cmd_seq_t
*commands
)
3451 struct sctp_chunk
*chunk
= arg
;
3452 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3456 if (!sctp_vtag_verify(chunk
, asoc
)) {
3457 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3459 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3462 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3463 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3464 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3467 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3468 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3469 len
= ntohs(chunk
->chunk_hdr
->length
);
3470 len
-= sizeof(struct sctp_chunkhdr
);
3471 skb_pull(chunk
->skb
, len
);
3473 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3474 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__
, tsn
);
3476 /* The TSN is too high--silently discard the chunk and count on it
3477 * getting retransmitted later.
3479 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3482 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3483 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3484 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3487 /* Go a head and force a SACK, since we are shutting down. */
3489 /* Implementor's Guide.
3491 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3492 * respond to each received packet containing one or more DATA chunk(s)
3493 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3495 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3496 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3497 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3498 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3500 return SCTP_DISPOSITION_CONSUME
;
3504 * Process an unknown chunk.
3506 * Section: 3.2. Also, 2.1 in the implementor's guide.
3508 * Chunk Types are encoded such that the highest-order two bits specify
3509 * the action that must be taken if the processing endpoint does not
3510 * recognize the Chunk Type.
3512 * 00 - Stop processing this SCTP packet and discard it, do not process
3513 * any further chunks within it.
3515 * 01 - Stop processing this SCTP packet and discard it, do not process
3516 * any further chunks within it, and report the unrecognized
3517 * chunk in an 'Unrecognized Chunk Type'.
3519 * 10 - Skip this chunk and continue processing.
3521 * 11 - Skip this chunk and continue processing, but report in an ERROR
3522 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3524 * The return value is the disposition of the chunk.
3526 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
3527 const struct sctp_association
*asoc
,
3528 const sctp_subtype_t type
,
3530 sctp_cmd_seq_t
*commands
)
3532 struct sctp_chunk
*unk_chunk
= arg
;
3533 struct sctp_chunk
*err_chunk
;
3534 sctp_chunkhdr_t
*hdr
;
3536 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
3538 if (!sctp_vtag_verify(unk_chunk
, asoc
))
3539 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3541 /* Make sure that the chunk has a valid length.
3542 * Since we don't know the chunk type, we use a general
3543 * chunkhdr structure to make a comparison.
3545 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
3546 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3549 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
3550 case SCTP_CID_ACTION_DISCARD
:
3551 /* Discard the packet. */
3552 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3554 case SCTP_CID_ACTION_DISCARD_ERR
:
3555 /* Discard the packet. */
3556 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3558 /* Generate an ERROR chunk as response. */
3559 hdr
= unk_chunk
->chunk_hdr
;
3560 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3561 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3562 WORD_ROUND(ntohs(hdr
->length
)));
3564 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3565 SCTP_CHUNK(err_chunk
));
3567 return SCTP_DISPOSITION_CONSUME
;
3569 case SCTP_CID_ACTION_SKIP
:
3570 /* Skip the chunk. */
3571 return SCTP_DISPOSITION_DISCARD
;
3573 case SCTP_CID_ACTION_SKIP_ERR
:
3574 /* Generate an ERROR chunk as response. */
3575 hdr
= unk_chunk
->chunk_hdr
;
3576 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3577 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3578 WORD_ROUND(ntohs(hdr
->length
)));
3580 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3581 SCTP_CHUNK(err_chunk
));
3583 /* Skip the chunk. */
3584 return SCTP_DISPOSITION_CONSUME
;
3590 return SCTP_DISPOSITION_DISCARD
;
3594 * Discard the chunk.
3596 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3597 * [Too numerous to mention...]
3598 * Verification Tag: No verification needed.
3600 * (endpoint, asoc, chunk)
3603 * (asoc, reply_msg, msg_up, timers, counters)
3605 * The return value is the disposition of the chunk.
3607 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
3608 const struct sctp_association
*asoc
,
3609 const sctp_subtype_t type
,
3611 sctp_cmd_seq_t
*commands
)
3613 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
3614 return SCTP_DISPOSITION_DISCARD
;
3618 * Discard the whole packet.
3622 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3623 * silently discard the OOTB packet and take no further action.
3625 * Verification Tag: No verification necessary
3628 * (endpoint, asoc, chunk)
3631 * (asoc, reply_msg, msg_up, timers, counters)
3633 * The return value is the disposition of the chunk.
3635 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
3636 const struct sctp_association
*asoc
,
3637 const sctp_subtype_t type
,
3639 sctp_cmd_seq_t
*commands
)
3641 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3643 return SCTP_DISPOSITION_CONSUME
;
3648 * The other end is violating protocol.
3650 * Section: Not specified
3651 * Verification Tag: Not specified
3653 * (endpoint, asoc, chunk)
3656 * (asoc, reply_msg, msg_up, timers, counters)
3658 * We simply tag the chunk as a violation. The state machine will log
3659 * the violation and continue.
3661 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
3662 const struct sctp_association
*asoc
,
3663 const sctp_subtype_t type
,
3665 sctp_cmd_seq_t
*commands
)
3667 return SCTP_DISPOSITION_VIOLATION
;
3672 * Handle a protocol violation when the chunk length is invalid.
3673 * "Invalid" length is identified as smaller then the minimal length a
3674 * given chunk can be. For example, a SACK chunk has invalid length
3675 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3677 * We inform the other end by sending an ABORT with a Protocol Violation
3680 * Section: Not specified
3681 * Verification Tag: Nothing to do
3683 * (endpoint, asoc, chunk)
3686 * (reply_msg, msg_up, counters)
3688 * Generate an ABORT chunk and terminate the association.
3690 sctp_disposition_t
sctp_sf_violation_chunklen(const struct sctp_endpoint
*ep
,
3691 const struct sctp_association
*asoc
,
3692 const sctp_subtype_t type
,
3694 sctp_cmd_seq_t
*commands
)
3696 struct sctp_chunk
*chunk
= arg
;
3697 struct sctp_chunk
*abort
= NULL
;
3698 char err_str
[]="The following chunk had invalid length:";
3700 /* Make the abort chunk. */
3701 abort
= sctp_make_abort_violation(asoc
, chunk
, err_str
,
3706 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
3707 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3709 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
3710 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3711 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
3712 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
3713 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION
));
3715 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3716 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION
));
3717 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3720 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3722 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3724 return SCTP_DISPOSITION_ABORT
;
3727 return SCTP_DISPOSITION_NOMEM
;
3730 /***************************************************************************
3731 * These are the state functions for handling primitive (Section 10) events.
3732 ***************************************************************************/
3734 * sctp_sf_do_prm_asoc
3736 * Section: 10.1 ULP-to-SCTP
3739 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3740 * outbound stream count)
3741 * -> association id [,destination transport addr list] [,outbound stream
3744 * This primitive allows the upper layer to initiate an association to a
3745 * specific peer endpoint.
3747 * The peer endpoint shall be specified by one of the transport addresses
3748 * which defines the endpoint (see Section 1.4). If the local SCTP
3749 * instance has not been initialized, the ASSOCIATE is considered an
3751 * [This is not relevant for the kernel implementation since we do all
3752 * initialization at boot time. It we hadn't initialized we wouldn't
3753 * get anywhere near this code.]
3755 * An association id, which is a local handle to the SCTP association,
3756 * will be returned on successful establishment of the association. If
3757 * SCTP is not able to open an SCTP association with the peer endpoint,
3758 * an error is returned.
3759 * [In the kernel implementation, the struct sctp_association needs to
3760 * be created BEFORE causing this primitive to run.]
3762 * Other association parameters may be returned, including the
3763 * complete destination transport addresses of the peer as well as the
3764 * outbound stream count of the local endpoint. One of the transport
3765 * address from the returned destination addresses will be selected by
3766 * the local endpoint as default primary path for sending SCTP packets
3767 * to this peer. The returned "destination transport addr list" can
3768 * be used by the ULP to change the default primary path or to force
3769 * sending a packet to a specific transport address. [All of this
3770 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3773 * Mandatory attributes:
3775 * o local SCTP instance name - obtained from the INITIALIZE operation.
3776 * [This is the argument asoc.]
3777 * o destination transport addr - specified as one of the transport
3778 * addresses of the peer endpoint with which the association is to be
3780 * [This is asoc->peer.active_path.]
3781 * o outbound stream count - the number of outbound streams the ULP
3782 * would like to open towards this peer endpoint.
3783 * [BUG: This is not currently implemented.]
3784 * Optional attributes:
3788 * The return value is a disposition.
3790 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
3791 const struct sctp_association
*asoc
,
3792 const sctp_subtype_t type
,
3794 sctp_cmd_seq_t
*commands
)
3796 struct sctp_chunk
*repl
;
3798 /* The comment below says that we enter COOKIE-WAIT AFTER
3799 * sending the INIT, but that doesn't actually work in our
3802 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3803 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
3805 /* RFC 2960 5.1 Normal Establishment of an Association
3807 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3808 * must provide its Verification Tag (Tag_A) in the Initiate
3809 * Tag field. Tag_A SHOULD be a random number in the range of
3810 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3813 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
3817 /* Cast away the const modifier, as we want to just
3818 * rerun it through as a sideffect.
3820 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
,
3821 SCTP_ASOC((struct sctp_association
*) asoc
));
3823 /* Choose transport for INIT. */
3824 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
3827 /* After sending the INIT, "A" starts the T1-init timer and
3828 * enters the COOKIE-WAIT state.
3830 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
3831 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
3832 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
3833 return SCTP_DISPOSITION_CONSUME
;
3836 return SCTP_DISPOSITION_NOMEM
;
3840 * Process the SEND primitive.
3842 * Section: 10.1 ULP-to-SCTP
3845 * Format: SEND(association id, buffer address, byte count [,context]
3846 * [,stream id] [,life time] [,destination transport address]
3847 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3850 * This is the main method to send user data via SCTP.
3852 * Mandatory attributes:
3854 * o association id - local handle to the SCTP association
3856 * o buffer address - the location where the user message to be
3857 * transmitted is stored;
3859 * o byte count - The size of the user data in number of bytes;
3861 * Optional attributes:
3863 * o context - an optional 32 bit integer that will be carried in the
3864 * sending failure notification to the ULP if the transportation of
3865 * this User Message fails.
3867 * o stream id - to indicate which stream to send the data on. If not
3868 * specified, stream 0 will be used.
3870 * o life time - specifies the life time of the user data. The user data
3871 * will not be sent by SCTP after the life time expires. This
3872 * parameter can be used to avoid efforts to transmit stale
3873 * user messages. SCTP notifies the ULP if the data cannot be
3874 * initiated to transport (i.e. sent to the destination via SCTP's
3875 * send primitive) within the life time variable. However, the
3876 * user data will be transmitted if SCTP has attempted to transmit a
3877 * chunk before the life time expired.
3879 * o destination transport address - specified as one of the destination
3880 * transport addresses of the peer endpoint to which this packet
3881 * should be sent. Whenever possible, SCTP should use this destination
3882 * transport address for sending the packets, instead of the current
3885 * o unorder flag - this flag, if present, indicates that the user
3886 * would like the data delivered in an unordered fashion to the peer
3887 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3890 * o no-bundle flag - instructs SCTP not to bundle this user data with
3891 * other outbound DATA chunks. SCTP MAY still bundle even when
3892 * this flag is present, when faced with network congestion.
3894 * o payload protocol-id - A 32 bit unsigned integer that is to be
3895 * passed to the peer indicating the type of payload protocol data
3896 * being transmitted. This value is passed as opaque data by SCTP.
3898 * The return value is the disposition.
3900 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
3901 const struct sctp_association
*asoc
,
3902 const sctp_subtype_t type
,
3904 sctp_cmd_seq_t
*commands
)
3906 struct sctp_chunk
*chunk
= arg
;
3908 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
3909 return SCTP_DISPOSITION_CONSUME
;
3913 * Process the SHUTDOWN primitive.
3918 * Format: SHUTDOWN(association id)
3921 * Gracefully closes an association. Any locally queued user data
3922 * will be delivered to the peer. The association will be terminated only
3923 * after the peer acknowledges all the SCTP packets sent. A success code
3924 * will be returned on successful termination of the association. If
3925 * attempting to terminate the association results in a failure, an error
3926 * code shall be returned.
3928 * Mandatory attributes:
3930 * o association id - local handle to the SCTP association
3932 * Optional attributes:
3936 * The return value is the disposition.
3938 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
3939 const struct sctp_endpoint
*ep
,
3940 const struct sctp_association
*asoc
,
3941 const sctp_subtype_t type
,
3943 sctp_cmd_seq_t
*commands
)
3947 /* From 9.2 Shutdown of an Association
3948 * Upon receipt of the SHUTDOWN primitive from its upper
3949 * layer, the endpoint enters SHUTDOWN-PENDING state and
3950 * remains there until all outstanding data has been
3951 * acknowledged by its peer. The endpoint accepts no new data
3952 * from its upper layer, but retransmits data to the far end
3953 * if necessary to fill gaps.
3955 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3956 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
3958 /* sctpimpguide-05 Section 2.12.2
3959 * The sender of the SHUTDOWN MAY also start an overall guard timer
3960 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3962 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
3963 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3965 disposition
= SCTP_DISPOSITION_CONSUME
;
3966 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
3967 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
3974 * Process the ABORT primitive.
3979 * Format: Abort(association id [, cause code])
3982 * Ungracefully closes an association. Any locally queued user data
3983 * will be discarded and an ABORT chunk is sent to the peer. A success code
3984 * will be returned on successful abortion of the association. If
3985 * attempting to abort the association results in a failure, an error
3986 * code shall be returned.
3988 * Mandatory attributes:
3990 * o association id - local handle to the SCTP association
3992 * Optional attributes:
3994 * o cause code - reason of the abort to be passed to the peer
3998 * The return value is the disposition.
4000 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4001 const struct sctp_endpoint
*ep
,
4002 const struct sctp_association
*asoc
,
4003 const sctp_subtype_t type
,
4005 sctp_cmd_seq_t
*commands
)
4007 /* From 9.1 Abort of an Association
4008 * Upon receipt of the ABORT primitive from its upper
4009 * layer, the endpoint enters CLOSED state and
4010 * discard all outstanding data has been
4011 * acknowledged by its peer. The endpoint accepts no new data
4012 * from its upper layer, but retransmits data to the far end
4013 * if necessary to fill gaps.
4015 struct msghdr
*msg
= arg
;
4016 struct sctp_chunk
*abort
;
4017 sctp_disposition_t retval
;
4019 retval
= SCTP_DISPOSITION_CONSUME
;
4021 /* Generate ABORT chunk to send the peer. */
4022 abort
= sctp_make_abort_user(asoc
, NULL
, msg
);
4024 retval
= SCTP_DISPOSITION_NOMEM
;
4026 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4028 /* Even if we can't send the ABORT due to low memory delete the
4029 * TCB. This is a departure from our typical NOMEM handling.
4032 /* Delete the established association. */
4033 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4034 SCTP_U32(SCTP_ERROR_USER_ABORT
));
4036 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4037 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4042 /* We tried an illegal operation on an association which is closed. */
4043 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4044 const struct sctp_association
*asoc
,
4045 const sctp_subtype_t type
,
4047 sctp_cmd_seq_t
*commands
)
4049 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4050 return SCTP_DISPOSITION_CONSUME
;
4053 /* We tried an illegal operation on an association which is shutting
4056 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4057 const struct sctp_association
*asoc
,
4058 const sctp_subtype_t type
,
4060 sctp_cmd_seq_t
*commands
)
4062 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4063 SCTP_ERROR(-ESHUTDOWN
));
4064 return SCTP_DISPOSITION_CONSUME
;
4068 * sctp_cookie_wait_prm_shutdown
4070 * Section: 4 Note: 2
4075 * The RFC does not explicitly address this issue, but is the route through the
4076 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4081 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4082 const struct sctp_endpoint
*ep
,
4083 const struct sctp_association
*asoc
,
4084 const sctp_subtype_t type
,
4086 sctp_cmd_seq_t
*commands
)
4088 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4089 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4091 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4092 SCTP_STATE(SCTP_STATE_CLOSED
));
4094 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4096 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4098 return SCTP_DISPOSITION_DELETE_TCB
;
4102 * sctp_cookie_echoed_prm_shutdown
4104 * Section: 4 Note: 2
4109 * The RFC does not explcitly address this issue, but is the route through the
4110 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4115 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4116 const struct sctp_endpoint
*ep
,
4117 const struct sctp_association
*asoc
,
4118 const sctp_subtype_t type
,
4119 void *arg
, sctp_cmd_seq_t
*commands
)
4121 /* There is a single T1 timer, so we should be able to use
4122 * common function with the COOKIE-WAIT state.
4124 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4128 * sctp_sf_cookie_wait_prm_abort
4130 * Section: 4 Note: 2
4135 * The RFC does not explicitly address this issue, but is the route through the
4136 * state table when someone issues an abort while in COOKIE_WAIT state.
4141 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4142 const struct sctp_endpoint
*ep
,
4143 const struct sctp_association
*asoc
,
4144 const sctp_subtype_t type
,
4146 sctp_cmd_seq_t
*commands
)
4148 struct msghdr
*msg
= arg
;
4149 struct sctp_chunk
*abort
;
4150 sctp_disposition_t retval
;
4152 /* Stop T1-init timer */
4153 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4154 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4155 retval
= SCTP_DISPOSITION_CONSUME
;
4157 /* Generate ABORT chunk to send the peer */
4158 abort
= sctp_make_abort_user(asoc
, NULL
, msg
);
4160 retval
= SCTP_DISPOSITION_NOMEM
;
4162 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4164 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4165 SCTP_STATE(SCTP_STATE_CLOSED
));
4167 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4169 /* Even if we can't send the ABORT due to low memory delete the
4170 * TCB. This is a departure from our typical NOMEM handling.
4173 /* Delete the established association. */
4174 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4175 SCTP_U32(SCTP_ERROR_USER_ABORT
));
4181 * sctp_sf_cookie_echoed_prm_abort
4183 * Section: 4 Note: 3
4188 * The RFC does not explcitly address this issue, but is the route through the
4189 * state table when someone issues an abort while in COOKIE_ECHOED state.
4194 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4195 const struct sctp_endpoint
*ep
,
4196 const struct sctp_association
*asoc
,
4197 const sctp_subtype_t type
,
4199 sctp_cmd_seq_t
*commands
)
4201 /* There is a single T1 timer, so we should be able to use
4202 * common function with the COOKIE-WAIT state.
4204 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4208 * sctp_sf_shutdown_pending_prm_abort
4213 * The RFC does not explicitly address this issue, but is the route through the
4214 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4219 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4220 const struct sctp_endpoint
*ep
,
4221 const struct sctp_association
*asoc
,
4222 const sctp_subtype_t type
,
4224 sctp_cmd_seq_t
*commands
)
4226 /* Stop the T5-shutdown guard timer. */
4227 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4228 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4230 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4234 * sctp_sf_shutdown_sent_prm_abort
4239 * The RFC does not explicitly address this issue, but is the route through the
4240 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4245 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4246 const struct sctp_endpoint
*ep
,
4247 const struct sctp_association
*asoc
,
4248 const sctp_subtype_t type
,
4250 sctp_cmd_seq_t
*commands
)
4252 /* Stop the T2-shutdown timer. */
4253 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4256 /* Stop the T5-shutdown guard timer. */
4257 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4258 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4260 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4264 * sctp_sf_cookie_echoed_prm_abort
4269 * The RFC does not explcitly address this issue, but is the route through the
4270 * state table when someone issues an abort while in COOKIE_ECHOED state.
4275 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4276 const struct sctp_endpoint
*ep
,
4277 const struct sctp_association
*asoc
,
4278 const sctp_subtype_t type
,
4280 sctp_cmd_seq_t
*commands
)
4282 /* The same T2 timer, so we should be able to use
4283 * common function with the SHUTDOWN-SENT state.
4285 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
4289 * Process the REQUESTHEARTBEAT primitive
4292 * J) Request Heartbeat
4294 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4298 * Instructs the local endpoint to perform a HeartBeat on the specified
4299 * destination transport address of the given association. The returned
4300 * result should indicate whether the transmission of the HEARTBEAT
4301 * chunk to the destination address is successful.
4303 * Mandatory attributes:
4305 * o association id - local handle to the SCTP association
4307 * o destination transport address - the transport address of the
4308 * association on which a heartbeat should be issued.
4310 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
4311 const struct sctp_endpoint
*ep
,
4312 const struct sctp_association
*asoc
,
4313 const sctp_subtype_t type
,
4315 sctp_cmd_seq_t
*commands
)
4317 return sctp_sf_heartbeat(ep
, asoc
, type
, (struct sctp_transport
*)arg
,
4322 * ADDIP Section 4.1 ASCONF Chunk Procedures
4323 * When an endpoint has an ASCONF signaled change to be sent to the
4324 * remote endpoint it should do A1 to A9
4326 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
4327 const struct sctp_association
*asoc
,
4328 const sctp_subtype_t type
,
4330 sctp_cmd_seq_t
*commands
)
4332 struct sctp_chunk
*chunk
= arg
;
4334 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
4335 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4336 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4337 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
4338 return SCTP_DISPOSITION_CONSUME
;
4342 * Ignore the primitive event
4344 * The return value is the disposition of the primitive.
4346 sctp_disposition_t
sctp_sf_ignore_primitive(
4347 const struct sctp_endpoint
*ep
,
4348 const struct sctp_association
*asoc
,
4349 const sctp_subtype_t type
,
4351 sctp_cmd_seq_t
*commands
)
4353 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
4354 return SCTP_DISPOSITION_DISCARD
;
4357 /***************************************************************************
4358 * These are the state functions for the OTHER events.
4359 ***************************************************************************/
4362 * Start the shutdown negotiation.
4365 * Once all its outstanding data has been acknowledged, the endpoint
4366 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4367 * TSN Ack field the last sequential TSN it has received from the peer.
4368 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4369 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4370 * with the updated last sequential TSN received from its peer.
4372 * The return value is the disposition.
4374 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
4375 const struct sctp_endpoint
*ep
,
4376 const struct sctp_association
*asoc
,
4377 const sctp_subtype_t type
,
4379 sctp_cmd_seq_t
*commands
)
4381 struct sctp_chunk
*reply
;
4383 /* Once all its outstanding data has been acknowledged, the
4384 * endpoint shall send a SHUTDOWN chunk to its peer including
4385 * in the Cumulative TSN Ack field the last sequential TSN it
4386 * has received from the peer.
4388 reply
= sctp_make_shutdown(asoc
, NULL
);
4392 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4393 * T2-shutdown timer.
4395 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4397 /* It shall then start the T2-shutdown timer */
4398 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4399 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4401 if (asoc
->autoclose
)
4402 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4403 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
4405 /* and enter the SHUTDOWN-SENT state. */
4406 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4407 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
4409 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4411 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4414 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
4416 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4418 return SCTP_DISPOSITION_CONSUME
;
4421 return SCTP_DISPOSITION_NOMEM
;
4425 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4429 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4430 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4431 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4432 * endpoint must re-send the SHUTDOWN ACK.
4434 * The return value is the disposition.
4436 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
4437 const struct sctp_endpoint
*ep
,
4438 const struct sctp_association
*asoc
,
4439 const sctp_subtype_t type
,
4441 sctp_cmd_seq_t
*commands
)
4443 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
4444 struct sctp_chunk
*reply
;
4446 /* There are 2 ways of getting here:
4447 * 1) called in response to a SHUTDOWN chunk
4448 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4450 * For the case (2), the arg parameter is set to NULL. We need
4451 * to check that we have a chunk before accessing it's fields.
4454 if (!sctp_vtag_verify(chunk
, asoc
))
4455 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4457 /* Make sure that the SHUTDOWN chunk has a valid length. */
4458 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
4459 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4463 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4464 * shall send a SHUTDOWN ACK ...
4466 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
4470 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4471 * the T2-shutdown timer.
4473 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4475 /* and start/restart a T2-shutdown timer of its own, */
4476 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4477 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4479 if (asoc
->autoclose
)
4480 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4481 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
4483 /* Enter the SHUTDOWN-ACK-SENT state. */
4484 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4485 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
4487 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4489 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4492 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
4494 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4496 return SCTP_DISPOSITION_CONSUME
;
4499 return SCTP_DISPOSITION_NOMEM
;
4503 * Ignore the event defined as other
4505 * The return value is the disposition of the event.
4507 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
4508 const struct sctp_association
*asoc
,
4509 const sctp_subtype_t type
,
4511 sctp_cmd_seq_t
*commands
)
4513 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
4514 return SCTP_DISPOSITION_DISCARD
;
4517 /************************************************************
4518 * These are the state functions for handling timeout events.
4519 ************************************************************/
4524 * Section: 6.3.3 Handle T3-rtx Expiration
4526 * Whenever the retransmission timer T3-rtx expires for a destination
4527 * address, do the following:
4530 * The return value is the disposition of the chunk.
4532 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
4533 const struct sctp_association
*asoc
,
4534 const sctp_subtype_t type
,
4536 sctp_cmd_seq_t
*commands
)
4538 struct sctp_transport
*transport
= arg
;
4540 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4541 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4542 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4543 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4544 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4545 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4546 return SCTP_DISPOSITION_DELETE_TCB
;
4549 /* E1) For the destination address for which the timer
4550 * expires, adjust its ssthresh with rules defined in Section
4551 * 7.2.3 and set the cwnd <- MTU.
4554 /* E2) For the destination address for which the timer
4555 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4556 * maximum value discussed in rule C7 above (RTO.max) may be
4557 * used to provide an upper bound to this doubling operation.
4560 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4561 * outstanding DATA chunks for the address for which the
4562 * T3-rtx has expired will fit into a single packet, subject
4563 * to the MTU constraint for the path corresponding to the
4564 * destination transport address to which the retransmission
4565 * is being sent (this may be different from the address for
4566 * which the timer expires [see Section 6.4]). Call this
4567 * value K. Bundle and retransmit those K DATA chunks in a
4568 * single packet to the destination endpoint.
4570 * Note: Any DATA chunks that were sent to the address for
4571 * which the T3-rtx timer expired but did not fit in one MTU
4572 * (rule E3 above), should be marked for retransmission and
4573 * sent as soon as cwnd allows (normally when a SACK arrives).
4576 /* NB: Rules E4 and F1 are implicit in R1. */
4577 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
4579 /* Do some failure management (Section 8.2). */
4580 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
4582 return SCTP_DISPOSITION_CONSUME
;
4586 * Generate delayed SACK on timeout
4588 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4590 * The guidelines on delayed acknowledgement algorithm specified in
4591 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4592 * acknowledgement SHOULD be generated for at least every second packet
4593 * (not every second DATA chunk) received, and SHOULD be generated
4594 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4595 * some situations it may be beneficial for an SCTP transmitter to be
4596 * more conservative than the algorithms detailed in this document
4597 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4598 * the following algorithms allow.
4600 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
4601 const struct sctp_association
*asoc
,
4602 const sctp_subtype_t type
,
4604 sctp_cmd_seq_t
*commands
)
4606 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
4607 return SCTP_DISPOSITION_CONSUME
;
4611 * sctp_sf_t1_init_timer_expire
4613 * Section: 4 Note: 2
4618 * RFC 2960 Section 4 Notes
4619 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4620 * and re-start the T1-init timer without changing state. This MUST
4621 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4622 * endpoint MUST abort the initialization process and report the
4623 * error to SCTP user.
4629 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
4630 const struct sctp_association
*asoc
,
4631 const sctp_subtype_t type
,
4633 sctp_cmd_seq_t
*commands
)
4635 struct sctp_chunk
*repl
= NULL
;
4636 struct sctp_bind_addr
*bp
;
4637 int attempts
= asoc
->init_err_counter
+ 1;
4639 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4641 if (attempts
< asoc
->max_init_attempts
) {
4642 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
4643 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
4645 return SCTP_DISPOSITION_NOMEM
;
4647 /* Choose transport for INIT. */
4648 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4651 /* Issue a sideeffect to do the needed accounting. */
4652 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
4653 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4655 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4657 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4658 " max_init_attempts: %d\n",
4659 attempts
, asoc
->max_init_attempts
);
4660 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4661 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4662 return SCTP_DISPOSITION_DELETE_TCB
;
4665 return SCTP_DISPOSITION_CONSUME
;
4669 * sctp_sf_t1_cookie_timer_expire
4671 * Section: 4 Note: 2
4676 * RFC 2960 Section 4 Notes
4677 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
4678 * COOKIE ECHO and re-start the T1-cookie timer without changing
4679 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4680 * After that, the endpoint MUST abort the initialization process and
4681 * report the error to SCTP user.
4687 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
4688 const struct sctp_association
*asoc
,
4689 const sctp_subtype_t type
,
4691 sctp_cmd_seq_t
*commands
)
4693 struct sctp_chunk
*repl
= NULL
;
4694 int attempts
= asoc
->init_err_counter
+ 1;
4696 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
4698 if (attempts
< asoc
->max_init_attempts
) {
4699 repl
= sctp_make_cookie_echo(asoc
, NULL
);
4701 return SCTP_DISPOSITION_NOMEM
;
4703 /* Issue a sideeffect to do the needed accounting. */
4704 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
4705 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
4707 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4709 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4710 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4711 return SCTP_DISPOSITION_DELETE_TCB
;
4714 return SCTP_DISPOSITION_CONSUME
;
4717 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4718 * with the updated last sequential TSN received from its peer.
4720 * An endpoint should limit the number of retransmissions of the
4721 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4722 * If this threshold is exceeded the endpoint should destroy the TCB and
4723 * MUST report the peer endpoint unreachable to the upper layer (and
4724 * thus the association enters the CLOSED state). The reception of any
4725 * packet from its peer (i.e. as the peer sends all of its queued DATA
4726 * chunks) should clear the endpoint's retransmission count and restart
4727 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4728 * all of its queued DATA chunks that have not yet been sent.
4730 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
4731 const struct sctp_association
*asoc
,
4732 const sctp_subtype_t type
,
4734 sctp_cmd_seq_t
*commands
)
4736 struct sctp_chunk
*reply
= NULL
;
4738 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4739 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4740 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4741 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4742 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4743 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4744 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4745 return SCTP_DISPOSITION_DELETE_TCB
;
4748 switch (asoc
->state
) {
4749 case SCTP_STATE_SHUTDOWN_SENT
:
4750 reply
= sctp_make_shutdown(asoc
, NULL
);
4753 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
4754 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
4765 /* Do some failure management (Section 8.2). */
4766 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
4767 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
4769 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4770 * the T2-shutdown timer.
4772 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4774 /* Restart the T2-shutdown timer. */
4775 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4776 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4777 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4778 return SCTP_DISPOSITION_CONSUME
;
4781 return SCTP_DISPOSITION_NOMEM
;
4785 * ADDIP Section 4.1 ASCONF CHunk Procedures
4786 * If the T4 RTO timer expires the endpoint should do B1 to B5
4788 sctp_disposition_t
sctp_sf_t4_timer_expire(
4789 const struct sctp_endpoint
*ep
,
4790 const struct sctp_association
*asoc
,
4791 const sctp_subtype_t type
,
4793 sctp_cmd_seq_t
*commands
)
4795 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
4796 struct sctp_transport
*transport
= chunk
->transport
;
4798 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4799 * detection on the appropriate destination address as defined in
4800 * RFC2960 [5] section 8.1 and 8.2.
4802 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
4804 /* Reconfig T4 timer and transport. */
4805 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
4807 /* ADDIP 4.1 B2) Increment the association error counters and perform
4808 * endpoint failure detection on the association as defined in
4809 * RFC2960 [5] section 8.1 and 8.2.
4810 * association error counter is incremented in SCTP_CMD_STRIKE.
4812 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
4813 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4814 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4815 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4816 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4817 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4818 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
4819 return SCTP_DISPOSITION_ABORT
;
4822 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4823 * the ASCONF chunk was sent by doubling the RTO timer value.
4824 * This is done in SCTP_CMD_STRIKE.
4827 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4828 * choose an alternate destination address (please refer to RFC2960
4829 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4830 * chunk, it MUST be the same (including its serial number) as the last
4833 sctp_chunk_hold(asoc
->addip_last_asconf
);
4834 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4835 SCTP_CHUNK(asoc
->addip_last_asconf
));
4837 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4838 * destination is selected, then the RTO used will be that of the new
4839 * destination address.
4841 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4842 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4844 return SCTP_DISPOSITION_CONSUME
;
4847 /* sctpimpguide-05 Section 2.12.2
4848 * The sender of the SHUTDOWN MAY also start an overall guard timer
4849 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4850 * At the expiration of this timer the sender SHOULD abort the association
4851 * by sending an ABORT chunk.
4853 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
4854 const struct sctp_association
*asoc
,
4855 const sctp_subtype_t type
,
4857 sctp_cmd_seq_t
*commands
)
4859 struct sctp_chunk
*reply
= NULL
;
4861 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4863 reply
= sctp_make_abort(asoc
, NULL
, 0);
4867 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
4868 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4869 SCTP_U32(SCTP_ERROR_NO_ERROR
));
4871 return SCTP_DISPOSITION_DELETE_TCB
;
4873 return SCTP_DISPOSITION_NOMEM
;
4876 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4877 * the association is automatically closed by starting the shutdown process.
4878 * The work that needs to be done is same as when SHUTDOWN is initiated by
4879 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4881 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
4882 const struct sctp_endpoint
*ep
,
4883 const struct sctp_association
*asoc
,
4884 const sctp_subtype_t type
,
4886 sctp_cmd_seq_t
*commands
)
4890 /* From 9.2 Shutdown of an Association
4891 * Upon receipt of the SHUTDOWN primitive from its upper
4892 * layer, the endpoint enters SHUTDOWN-PENDING state and
4893 * remains there until all outstanding data has been
4894 * acknowledged by its peer. The endpoint accepts no new data
4895 * from its upper layer, but retransmits data to the far end
4896 * if necessary to fill gaps.
4898 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4899 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4901 /* sctpimpguide-05 Section 2.12.2
4902 * The sender of the SHUTDOWN MAY also start an overall guard timer
4903 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4905 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4906 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4907 disposition
= SCTP_DISPOSITION_CONSUME
;
4908 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4909 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4915 /*****************************************************************************
4916 * These are sa state functions which could apply to all types of events.
4917 ****************************************************************************/
4920 * This table entry is not implemented.
4923 * (endpoint, asoc, chunk)
4925 * The return value is the disposition of the chunk.
4927 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
4928 const struct sctp_association
*asoc
,
4929 const sctp_subtype_t type
,
4931 sctp_cmd_seq_t
*commands
)
4933 return SCTP_DISPOSITION_NOT_IMPL
;
4937 * This table entry represents a bug.
4940 * (endpoint, asoc, chunk)
4942 * The return value is the disposition of the chunk.
4944 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
4945 const struct sctp_association
*asoc
,
4946 const sctp_subtype_t type
,
4948 sctp_cmd_seq_t
*commands
)
4950 return SCTP_DISPOSITION_BUG
;
4954 * This table entry represents the firing of a timer in the wrong state.
4955 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4956 * when the association is in the wrong state. This event should
4957 * be ignored, so as to prevent any rearming of the timer.
4960 * (endpoint, asoc, chunk)
4962 * The return value is the disposition of the chunk.
4964 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
4965 const struct sctp_association
*asoc
,
4966 const sctp_subtype_t type
,
4968 sctp_cmd_seq_t
*commands
)
4970 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
4971 return SCTP_DISPOSITION_CONSUME
;
4974 /********************************************************************
4975 * 2nd Level Abstractions
4976 ********************************************************************/
4978 /* Pull the SACK chunk based on the SACK header. */
4979 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
4981 struct sctp_sackhdr
*sack
;
4986 /* Protect ourselves from reading too far into
4987 * the skb from a bogus sender.
4989 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
4991 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
4992 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
4993 len
= sizeof(struct sctp_sackhdr
);
4994 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
4995 if (len
> chunk
->skb
->len
)
4998 skb_pull(chunk
->skb
, len
);
5003 /* Create an ABORT packet to be sent as a response, with the specified
5006 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5007 const struct sctp_association
*asoc
,
5008 struct sctp_chunk
*chunk
,
5009 const void *payload
,
5012 struct sctp_packet
*packet
;
5013 struct sctp_chunk
*abort
;
5015 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5019 * The T bit will be set if the asoc is NULL.
5021 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5023 sctp_ootb_pkt_free(packet
);
5027 /* Reflect vtag if T-Bit is set */
5028 if (sctp_test_T_bit(abort
))
5029 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5031 /* Add specified error causes, i.e., payload, to the
5034 sctp_addto_chunk(abort
, paylen
, payload
);
5036 /* Set the skb to the belonging sock for accounting. */
5037 abort
->skb
->sk
= ep
->base
.sk
;
5039 sctp_packet_append_chunk(packet
, abort
);
5046 /* Allocate a packet for responding in the OOTB conditions. */
5047 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5048 const struct sctp_chunk
*chunk
)
5050 struct sctp_packet
*packet
;
5051 struct sctp_transport
*transport
;
5056 /* Get the source and destination port from the inbound packet. */
5057 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5058 dport
= ntohs(chunk
->sctp_hdr
->source
);
5060 /* The V-tag is going to be the same as the inbound packet if no
5061 * association exists, otherwise, use the peer's vtag.
5064 vtag
= asoc
->peer
.i
.init_tag
;
5066 /* Special case the INIT and stale COOKIE_ECHO as there is no
5069 switch(chunk
->chunk_hdr
->type
) {
5072 sctp_init_chunk_t
*init
;
5074 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5075 vtag
= ntohl(init
->init_hdr
.init_tag
);
5079 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5084 /* Make a transport for the bucket, Eliza... */
5085 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5089 /* Cache a route for the transport with the chunk's destination as
5090 * the source address.
5092 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5093 sctp_sk(sctp_get_ctl_sock()));
5095 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5096 packet
= sctp_packet_config(packet
, vtag
, 0);
5104 /* Free the packet allocated earlier for responding in the OOTB condition. */
5105 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5107 sctp_transport_free(packet
->transport
);
5110 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5111 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5112 const struct sctp_association
*asoc
,
5113 const struct sctp_chunk
*chunk
,
5114 sctp_cmd_seq_t
*commands
,
5115 struct sctp_chunk
*err_chunk
)
5117 struct sctp_packet
*packet
;
5120 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5122 struct sctp_signed_cookie
*cookie
;
5124 /* Override the OOTB vtag from the cookie. */
5125 cookie
= chunk
->subh
.cookie_hdr
;
5126 packet
->vtag
= cookie
->c
.peer_vtag
;
5128 /* Set the skb to the belonging sock for accounting. */
5129 err_chunk
->skb
->sk
= ep
->base
.sk
;
5130 sctp_packet_append_chunk(packet
, err_chunk
);
5131 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5132 SCTP_PACKET(packet
));
5133 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5135 sctp_chunk_free (err_chunk
);
5140 /* Process a data chunk */
5141 static int sctp_eat_data(const struct sctp_association
*asoc
,
5142 struct sctp_chunk
*chunk
,
5143 sctp_cmd_seq_t
*commands
)
5145 sctp_datahdr_t
*data_hdr
;
5146 struct sctp_chunk
*err
;
5148 sctp_verb_t deliver
;
5152 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5153 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5155 tsn
= ntohl(data_hdr
->tsn
);
5156 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5158 /* ASSERT: Now skb->data is really the user data. */
5160 /* Process ECN based congestion.
5162 * Since the chunk structure is reused for all chunks within
5163 * a packet, we use ecn_ce_done to track if we've already
5164 * done CE processing for this packet.
5166 * We need to do ECN processing even if we plan to discard the
5170 if (!chunk
->ecn_ce_done
) {
5172 chunk
->ecn_ce_done
= 1;
5174 af
= sctp_get_af_specific(
5175 ipver2af(chunk
->skb
->nh
.iph
->version
));
5177 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
5178 /* Do real work as sideffect. */
5179 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
5184 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
5186 /* The TSN is too high--silently discard the chunk and
5187 * count on it getting retransmitted later.
5189 return SCTP_IERROR_HIGH_TSN
;
5190 } else if (tmp
> 0) {
5191 /* This is a duplicate. Record it. */
5192 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
5193 return SCTP_IERROR_DUP_TSN
;
5196 /* This is a new TSN. */
5198 /* Discard if there is no room in the receive window.
5199 * Actually, allow a little bit of overflow (up to a MTU).
5201 datalen
= ntohs(chunk
->chunk_hdr
->length
);
5202 datalen
-= sizeof(sctp_data_chunk_t
);
5204 deliver
= SCTP_CMD_CHUNK_ULP
;
5206 /* Think about partial delivery. */
5207 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
5209 /* Even if we don't accept this chunk there is
5212 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
5215 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5216 * seems a bit troublesome in that frag_point varies based on
5217 * PMTU. In cases, such as loopback, this might be a rather
5220 if (!asoc
->rwnd
|| asoc
->rwnd_over
||
5221 (datalen
> asoc
->rwnd
+ asoc
->frag_point
)) {
5223 /* If this is the next TSN, consider reneging to make
5224 * room. Note: Playing nice with a confused sender. A
5225 * malicious sender can still eat up all our buffer
5226 * space and in the future we may want to detect and
5227 * do more drastic reneging.
5229 if (sctp_tsnmap_has_gap(&asoc
->peer
.tsn_map
) &&
5230 (sctp_tsnmap_get_ctsn(&asoc
->peer
.tsn_map
) + 1) == tsn
) {
5231 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
5232 deliver
= SCTP_CMD_RENEGE
;
5234 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5235 "rwnd: %d\n", tsn
, datalen
,
5237 return SCTP_IERROR_IGNORE_TSN
;
5242 * Section 3.3.10.9 No User Data (9)
5246 * No User Data: This error cause is returned to the originator of a
5247 * DATA chunk if a received DATA chunk has no user data.
5249 if (unlikely(0 == datalen
)) {
5250 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
5252 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5255 /* We are going to ABORT, so we might as well stop
5256 * processing the rest of the chunks in the packet.
5258 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
5259 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5260 SCTP_U32(SCTP_ERROR_NO_DATA
));
5261 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5262 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5263 return SCTP_IERROR_NO_DATA
;
5266 /* If definately accepting the DATA chunk, record its TSN, otherwise
5267 * wait for renege processing.
5269 if (SCTP_CMD_CHUNK_ULP
== deliver
)
5270 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
5272 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5273 * if we renege and the chunk arrives again.
5275 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
5276 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
5278 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
5280 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5282 * If an endpoint receive a DATA chunk with an invalid stream
5283 * identifier, it shall acknowledge the reception of the DATA chunk
5284 * following the normal procedure, immediately send an ERROR chunk
5285 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5286 * and discard the DATA chunk.
5288 if (ntohs(data_hdr
->stream
) >= asoc
->c
.sinit_max_instreams
) {
5289 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
5291 sizeof(data_hdr
->stream
));
5293 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5295 return SCTP_IERROR_BAD_STREAM
;
5298 /* Send the data up to the user. Note: Schedule the
5299 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5300 * chunk needs the updated rwnd.
5302 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
5304 return SCTP_IERROR_NO_ERROR
;