1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
8 * This is part of the SCTP Linux Kernel Implementation.
10 * These are the state functions for the state machine.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
53 #include <linux/types.h>
54 #include <linux/kernel.h>
56 #include <linux/ipv6.h>
57 #include <linux/net.h>
58 #include <linux/inet.h>
60 #include <net/inet_ecn.h>
61 #include <linux/skbuff.h>
62 #include <net/sctp/sctp.h>
63 #include <net/sctp/sm.h>
64 #include <net/sctp/structs.h>
66 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
67 const struct sctp_association *asoc,
68 struct sctp_chunk *chunk,
71 static int sctp_eat_data(const struct sctp_association *asoc,
72 struct sctp_chunk *chunk,
73 sctp_cmd_seq_t *commands);
74 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
75 const struct sctp_chunk *chunk);
76 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
77 const struct sctp_association *asoc,
78 const struct sctp_chunk *chunk,
79 sctp_cmd_seq_t *commands,
80 struct sctp_chunk *err_chunk);
81 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
82 const struct sctp_association *asoc,
83 const sctp_subtype_t type,
85 sctp_cmd_seq_t *commands);
86 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
87 const struct sctp_association *asoc,
88 const sctp_subtype_t type,
90 sctp_cmd_seq_t *commands);
91 static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
92 const struct sctp_association *asoc,
93 const sctp_subtype_t type,
95 sctp_cmd_seq_t *commands);
96 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
98 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
99 __be16 error, int sk_err,
100 const struct sctp_association *asoc,
101 struct sctp_transport *transport);
103 static sctp_disposition_t sctp_sf_abort_violation(
104 const struct sctp_endpoint *ep,
105 const struct sctp_association *asoc,
107 sctp_cmd_seq_t *commands,
109 const size_t paylen);
111 static sctp_disposition_t sctp_sf_violation_chunklen(
112 const struct sctp_endpoint *ep,
113 const struct sctp_association *asoc,
114 const sctp_subtype_t type,
116 sctp_cmd_seq_t *commands);
118 static sctp_disposition_t sctp_sf_violation_paramlen(
119 const struct sctp_endpoint *ep,
120 const struct sctp_association *asoc,
121 const sctp_subtype_t type,
123 sctp_cmd_seq_t *commands);
125 static sctp_disposition_t sctp_sf_violation_ctsn(
126 const struct sctp_endpoint *ep,
127 const struct sctp_association *asoc,
128 const sctp_subtype_t type,
130 sctp_cmd_seq_t *commands);
132 static sctp_disposition_t sctp_sf_violation_chunk(
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const sctp_subtype_t type,
137 sctp_cmd_seq_t *commands);
139 static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
140 const struct sctp_association *asoc,
141 const sctp_subtype_t type,
142 struct sctp_chunk *chunk);
144 static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
145 const struct sctp_association *asoc,
146 const sctp_subtype_t type,
148 sctp_cmd_seq_t *commands);
150 /* Small helper function that checks if the chunk length
151 * is of the appropriate length. The 'required_length' argument
152 * is set to be the size of a specific chunk we are testing.
153 * Return Values: 1 = Valid length
158 sctp_chunk_length_valid(struct sctp_chunk *chunk,
159 __u16 required_length)
161 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
163 if (unlikely(chunk_length < required_length))
169 /**********************************************************
170 * These are the state functions for handling chunk events.
171 **********************************************************/
174 * Process the final SHUTDOWN COMPLETE.
176 * Section: 4 (C) (diagram), 9.2
177 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
178 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
179 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
180 * should stop the T2-shutdown timer and remove all knowledge of the
181 * association (and thus the association enters the CLOSED state).
183 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
184 * C) Rules for packet carrying SHUTDOWN COMPLETE:
186 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
187 * if the Verification Tag field of the packet matches its own tag and
188 * the T bit is not set
190 * it is set to its peer's tag and the T bit is set in the Chunk
192 * Otherwise, the receiver MUST silently discard the packet
193 * and take no further action. An endpoint MUST ignore the
194 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
197 * (endpoint, asoc, chunk)
200 * (asoc, reply_msg, msg_up, timers, counters)
202 * The return value is the disposition of the chunk.
204 sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
205 const struct sctp_association *asoc,
206 const sctp_subtype_t type,
208 sctp_cmd_seq_t *commands)
210 struct sctp_chunk *chunk = arg;
211 struct sctp_ulpevent *ev;
213 if (!sctp_vtag_verify_either(chunk, asoc))
214 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
216 /* RFC 2960 6.10 Bundling
218 * An endpoint MUST NOT bundle INIT, INIT ACK or
219 * SHUTDOWN COMPLETE with any other chunks.
221 if (!chunk->singleton)
222 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
224 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
225 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
226 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
229 /* RFC 2960 10.2 SCTP-to-ULP
231 * H) SHUTDOWN COMPLETE notification
233 * When SCTP completes the shutdown procedures (section 9.2) this
234 * notification is passed to the upper layer.
236 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
237 0, 0, 0, NULL, GFP_ATOMIC);
239 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
242 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
243 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
244 * not the chunk should be discarded. If the endpoint is in
245 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
246 * T2-shutdown timer and remove all knowledge of the
247 * association (and thus the association enters the CLOSED
250 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
251 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
253 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
256 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
257 SCTP_STATE(SCTP_STATE_CLOSED));
259 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
260 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
262 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
264 return SCTP_DISPOSITION_DELETE_TCB;
268 * Respond to a normal INIT chunk.
269 * We are the side that is being asked for an association.
271 * Section: 5.1 Normal Establishment of an Association, B
272 * B) "Z" shall respond immediately with an INIT ACK chunk. The
273 * destination IP address of the INIT ACK MUST be set to the source
274 * IP address of the INIT to which this INIT ACK is responding. In
275 * the response, besides filling in other parameters, "Z" must set the
276 * Verification Tag field to Tag_A, and also provide its own
277 * Verification Tag (Tag_Z) in the Initiate Tag field.
279 * Verification Tag: Must be 0.
282 * (endpoint, asoc, chunk)
285 * (asoc, reply_msg, msg_up, timers, counters)
287 * The return value is the disposition of the chunk.
289 sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
290 const struct sctp_association *asoc,
291 const sctp_subtype_t type,
293 sctp_cmd_seq_t *commands)
295 struct sctp_chunk *chunk = arg;
296 struct sctp_chunk *repl;
297 struct sctp_association *new_asoc;
298 struct sctp_chunk *err_chunk;
299 struct sctp_packet *packet;
300 sctp_unrecognized_param_t *unk_param;
304 * An endpoint MUST NOT bundle INIT, INIT ACK or
305 * SHUTDOWN COMPLETE with any other chunks.
308 * Furthermore, we require that the receiver of an INIT chunk MUST
309 * enforce these rules by silently discarding an arriving packet
310 * with an INIT chunk that is bundled with other chunks.
312 if (!chunk->singleton)
313 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
315 /* If the packet is an OOTB packet which is temporarily on the
316 * control endpoint, respond with an ABORT.
318 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
319 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
321 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
324 if (chunk->sctp_hdr->vtag != 0)
325 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
327 /* Make sure that the INIT chunk has a valid length.
328 * Normally, this would cause an ABORT with a Protocol Violation
329 * error, but since we don't have an association, we'll
330 * just discard the packet.
332 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
333 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
335 /* Verify the INIT chunk before processing it. */
337 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
338 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
340 /* This chunk contains fatal error. It is to be discarded.
341 * Send an ABORT, with causes if there is any.
344 packet = sctp_abort_pkt_new(ep, asoc, arg,
345 (__u8 *)(err_chunk->chunk_hdr) +
346 sizeof(sctp_chunkhdr_t),
347 ntohs(err_chunk->chunk_hdr->length) -
348 sizeof(sctp_chunkhdr_t));
350 sctp_chunk_free(err_chunk);
353 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
354 SCTP_PACKET(packet));
355 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
356 return SCTP_DISPOSITION_CONSUME;
358 return SCTP_DISPOSITION_NOMEM;
361 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
366 /* Grab the INIT header. */
367 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
369 /* Tag the variable length parameters. */
370 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
372 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
376 /* The call, sctp_process_init(), can fail on memory allocation. */
377 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
379 (sctp_init_chunk_t *)chunk->chunk_hdr,
383 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
385 /* If there are errors need to be reported for unknown parameters,
386 * make sure to reserve enough room in the INIT ACK for them.
390 len = ntohs(err_chunk->chunk_hdr->length) -
391 sizeof(sctp_chunkhdr_t);
393 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
396 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
400 /* If there are errors need to be reported for unknown parameters,
401 * include them in the outgoing INIT ACK as "Unrecognized parameter"
405 /* Get the "Unrecognized parameter" parameter(s) out of the
406 * ERROR chunk generated by sctp_verify_init(). Since the
407 * error cause code for "unknown parameter" and the
408 * "Unrecognized parameter" type is the same, we can
409 * construct the parameters in INIT ACK by copying the
412 unk_param = (sctp_unrecognized_param_t *)
413 ((__u8 *)(err_chunk->chunk_hdr) +
414 sizeof(sctp_chunkhdr_t));
415 /* Replace the cause code with the "Unrecognized parameter"
418 sctp_addto_chunk(repl, len, unk_param);
419 sctp_chunk_free(err_chunk);
422 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
424 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
427 * Note: After sending out INIT ACK with the State Cookie parameter,
428 * "Z" MUST NOT allocate any resources, nor keep any states for the
429 * new association. Otherwise, "Z" will be vulnerable to resource
432 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
434 return SCTP_DISPOSITION_DELETE_TCB;
437 sctp_association_free(new_asoc);
440 sctp_chunk_free(err_chunk);
441 return SCTP_DISPOSITION_NOMEM;
445 * Respond to a normal INIT ACK chunk.
446 * We are the side that is initiating the association.
448 * Section: 5.1 Normal Establishment of an Association, C
449 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
450 * timer and leave COOKIE-WAIT state. "A" shall then send the State
451 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
452 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
454 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
455 * DATA chunks, but it MUST be the first chunk in the packet and
456 * until the COOKIE ACK is returned the sender MUST NOT send any
457 * other packets to the peer.
459 * Verification Tag: 3.3.3
460 * If the value of the Initiate Tag in a received INIT ACK chunk is
461 * found to be 0, the receiver MUST treat it as an error and close the
462 * association by transmitting an ABORT.
465 * (endpoint, asoc, chunk)
468 * (asoc, reply_msg, msg_up, timers, counters)
470 * The return value is the disposition of the chunk.
472 sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
473 const struct sctp_association *asoc,
474 const sctp_subtype_t type,
476 sctp_cmd_seq_t *commands)
478 struct sctp_chunk *chunk = arg;
479 sctp_init_chunk_t *initchunk;
480 struct sctp_chunk *err_chunk;
481 struct sctp_packet *packet;
483 if (!sctp_vtag_verify(chunk, asoc))
484 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
487 * An endpoint MUST NOT bundle INIT, INIT ACK or
488 * SHUTDOWN COMPLETE with any other chunks.
490 if (!chunk->singleton)
491 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
493 /* Make sure that the INIT-ACK chunk has a valid length */
494 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
495 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
497 /* Grab the INIT header. */
498 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
500 /* Verify the INIT chunk before processing it. */
502 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
503 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
506 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
508 /* This chunk contains fatal error. It is to be discarded.
509 * Send an ABORT, with causes. If there are no causes,
510 * then there wasn't enough memory. Just terminate
514 packet = sctp_abort_pkt_new(ep, asoc, arg,
515 (__u8 *)(err_chunk->chunk_hdr) +
516 sizeof(sctp_chunkhdr_t),
517 ntohs(err_chunk->chunk_hdr->length) -
518 sizeof(sctp_chunkhdr_t));
520 sctp_chunk_free(err_chunk);
523 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
524 SCTP_PACKET(packet));
525 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
526 error = SCTP_ERROR_INV_PARAM;
530 /* SCTP-AUTH, Section 6.3:
531 * It should be noted that if the receiver wants to tear
532 * down an association in an authenticated way only, the
533 * handling of malformed packets should not result in
534 * tearing down the association.
536 * This means that if we only want to abort associations
537 * in an authenticated way (i.e AUTH+ABORT), then we
538 * can't destroy this association just becuase the packet
541 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
542 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
544 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
545 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
546 asoc, chunk->transport);
549 /* Tag the variable length parameters. Note that we never
550 * convert the parameters in an INIT chunk.
552 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
554 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
556 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
557 SCTP_PEER_INIT(initchunk));
559 /* Reset init error count upon receipt of INIT-ACK. */
560 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
562 /* 5.1 C) "A" shall stop the T1-init timer and leave
563 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
564 * timer, and enter the COOKIE-ECHOED state.
566 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
567 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
568 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
569 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
570 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
571 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
573 /* SCTP-AUTH: genereate the assocition shared keys so that
574 * we can potentially signe the COOKIE-ECHO.
576 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
578 /* 5.1 C) "A" shall then send the State Cookie received in the
579 * INIT ACK chunk in a COOKIE ECHO chunk, ...
581 /* If there is any errors to report, send the ERROR chunk generated
582 * for unknown parameters as well.
584 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
585 SCTP_CHUNK(err_chunk));
587 return SCTP_DISPOSITION_CONSUME;
591 * Respond to a normal COOKIE ECHO chunk.
592 * We are the side that is being asked for an association.
594 * Section: 5.1 Normal Establishment of an Association, D
595 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
596 * with a COOKIE ACK chunk after building a TCB and moving to
597 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
598 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
599 * chunk MUST be the first chunk in the packet.
601 * IMPLEMENTATION NOTE: An implementation may choose to send the
602 * Communication Up notification to the SCTP user upon reception
603 * of a valid COOKIE ECHO chunk.
605 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
606 * D) Rules for packet carrying a COOKIE ECHO
608 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
609 * Initial Tag received in the INIT ACK.
611 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
614 * (endpoint, asoc, chunk)
617 * (asoc, reply_msg, msg_up, timers, counters)
619 * The return value is the disposition of the chunk.
621 sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
622 const struct sctp_association *asoc,
623 const sctp_subtype_t type, void *arg,
624 sctp_cmd_seq_t *commands)
626 struct sctp_chunk *chunk = arg;
627 struct sctp_association *new_asoc;
628 sctp_init_chunk_t *peer_init;
629 struct sctp_chunk *repl;
630 struct sctp_ulpevent *ev, *ai_ev = NULL;
632 struct sctp_chunk *err_chk_p;
635 /* If the packet is an OOTB packet which is temporarily on the
636 * control endpoint, respond with an ABORT.
638 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
639 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
641 /* Make sure that the COOKIE_ECHO chunk has a valid length.
642 * In this case, we check that we have enough for at least a
643 * chunk header. More detailed verification is done
644 * in sctp_unpack_cookie().
646 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
647 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
649 /* If the endpoint is not listening or if the number of associations
650 * on the TCP-style socket exceed the max backlog, respond with an
654 if (!sctp_sstate(sk, LISTENING) ||
655 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
656 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
658 /* "Decode" the chunk. We have no optional parameters so we
661 chunk->subh.cookie_hdr =
662 (struct sctp_signed_cookie *)chunk->skb->data;
663 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
664 sizeof(sctp_chunkhdr_t)))
667 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
668 * "Z" will reply with a COOKIE ACK chunk after building a TCB
669 * and moving to the ESTABLISHED state.
671 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
675 * If the re-build failed, what is the proper error path
678 * [We should abort the association. --piggy]
681 /* FIXME: Several errors are possible. A bad cookie should
682 * be silently discarded, but think about logging it too.
685 case -SCTP_IERROR_NOMEM:
688 case -SCTP_IERROR_STALE_COOKIE:
689 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
691 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
693 case -SCTP_IERROR_BAD_SIG:
695 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
700 /* Delay state machine commands until later.
702 * Re-build the bind address for the association is done in
703 * the sctp_unpack_cookie() already.
705 /* This is a brand-new association, so these are not yet side
706 * effects--it is safe to run them here.
708 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
710 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
711 &chunk->subh.cookie_hdr->c.peer_addr,
712 peer_init, GFP_ATOMIC))
715 /* SCTP-AUTH: Now that we've populate required fields in
716 * sctp_process_init, set up the assocaition shared keys as
717 * necessary so that we can potentially authenticate the ACK
719 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
723 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
724 * is supposed to be authenticated and we have to do delayed
725 * authentication. We've just recreated the association using
726 * the information in the cookie and now it's much easier to
727 * do the authentication.
729 if (chunk->auth_chunk) {
730 struct sctp_chunk auth;
733 /* set-up our fake chunk so that we can process it */
734 auth.skb = chunk->auth_chunk;
735 auth.asoc = chunk->asoc;
736 auth.sctp_hdr = chunk->sctp_hdr;
737 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
738 sizeof(sctp_chunkhdr_t));
739 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
740 auth.transport = chunk->transport;
742 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
744 /* We can now safely free the auth_chunk clone */
745 kfree_skb(chunk->auth_chunk);
747 if (ret != SCTP_IERROR_NO_ERROR) {
748 sctp_association_free(new_asoc);
749 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
753 repl = sctp_make_cookie_ack(new_asoc, chunk);
757 /* RFC 2960 5.1 Normal Establishment of an Association
759 * D) IMPLEMENTATION NOTE: An implementation may choose to
760 * send the Communication Up notification to the SCTP user
761 * upon reception of a valid COOKIE ECHO chunk.
763 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
764 new_asoc->c.sinit_num_ostreams,
765 new_asoc->c.sinit_max_instreams,
770 /* Sockets API Draft Section 5.3.1.6
771 * When a peer sends a Adaptation Layer Indication parameter , SCTP
772 * delivers this notification to inform the application that of the
773 * peers requested adaptation layer.
775 if (new_asoc->peer.adaptation_ind) {
776 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
782 /* Add all the state machine commands now since we've created
783 * everything. This way we don't introduce memory corruptions
784 * during side-effect processing and correclty count established
787 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
788 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
789 SCTP_STATE(SCTP_STATE_ESTABLISHED));
790 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
791 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
792 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
794 if (new_asoc->autoclose)
795 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
796 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
798 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
800 /* This will send the COOKIE ACK */
801 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
803 /* Queue the ASSOC_CHANGE event */
804 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
806 /* Send up the Adaptation Layer Indication event */
808 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
809 SCTP_ULPEVENT(ai_ev));
811 return SCTP_DISPOSITION_CONSUME;
814 sctp_ulpevent_free(ev);
816 sctp_chunk_free(repl);
818 sctp_association_free(new_asoc);
820 return SCTP_DISPOSITION_NOMEM;
824 * Respond to a normal COOKIE ACK chunk.
825 * We are the side that is being asked for an association.
827 * RFC 2960 5.1 Normal Establishment of an Association
829 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
830 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
831 * timer. It may also notify its ULP about the successful
832 * establishment of the association with a Communication Up
833 * notification (see Section 10).
837 * (endpoint, asoc, chunk)
840 * (asoc, reply_msg, msg_up, timers, counters)
842 * The return value is the disposition of the chunk.
844 sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
845 const struct sctp_association *asoc,
846 const sctp_subtype_t type, void *arg,
847 sctp_cmd_seq_t *commands)
849 struct sctp_chunk *chunk = arg;
850 struct sctp_ulpevent *ev;
852 if (!sctp_vtag_verify(chunk, asoc))
853 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
855 /* Verify that the chunk length for the COOKIE-ACK is OK.
856 * If we don't do this, any bundled chunks may be junked.
858 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
859 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
862 /* Reset init error count upon receipt of COOKIE-ACK,
863 * to avoid problems with the managemement of this
864 * counter in stale cookie situations when a transition back
865 * from the COOKIE-ECHOED state to the COOKIE-WAIT
866 * state is performed.
868 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
870 /* RFC 2960 5.1 Normal Establishment of an Association
872 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
873 * from the COOKIE-ECHOED state to the ESTABLISHED state,
874 * stopping the T1-cookie timer.
876 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
877 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
878 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
879 SCTP_STATE(SCTP_STATE_ESTABLISHED));
880 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
881 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
882 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
884 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
885 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
886 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
888 /* It may also notify its ULP about the successful
889 * establishment of the association with a Communication Up
890 * notification (see Section 10).
892 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
893 0, asoc->c.sinit_num_ostreams,
894 asoc->c.sinit_max_instreams,
900 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
902 /* Sockets API Draft Section 5.3.1.6
903 * When a peer sends a Adaptation Layer Indication parameter , SCTP
904 * delivers this notification to inform the application that of the
905 * peers requested adaptation layer.
907 if (asoc->peer.adaptation_ind) {
908 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
912 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
916 return SCTP_DISPOSITION_CONSUME;
918 return SCTP_DISPOSITION_NOMEM;
921 /* Generate and sendout a heartbeat packet. */
922 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
923 const struct sctp_association *asoc,
924 const sctp_subtype_t type,
926 sctp_cmd_seq_t *commands)
928 struct sctp_transport *transport = (struct sctp_transport *) arg;
929 struct sctp_chunk *reply;
930 sctp_sender_hb_info_t hbinfo;
933 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
934 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
935 hbinfo.daddr = transport->ipaddr;
936 hbinfo.sent_at = jiffies;
937 hbinfo.hb_nonce = transport->hb_nonce;
939 /* Send a heartbeat to our peer. */
940 paylen = sizeof(sctp_sender_hb_info_t);
941 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
943 return SCTP_DISPOSITION_NOMEM;
945 /* Set rto_pending indicating that an RTT measurement
946 * is started with this heartbeat chunk.
948 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
949 SCTP_TRANSPORT(transport));
951 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
952 return SCTP_DISPOSITION_CONSUME;
955 /* Generate a HEARTBEAT packet on the given transport. */
956 sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
957 const struct sctp_association *asoc,
958 const sctp_subtype_t type,
960 sctp_cmd_seq_t *commands)
962 struct sctp_transport *transport = (struct sctp_transport *) arg;
964 if (asoc->overall_error_count > asoc->max_retrans) {
965 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
966 SCTP_ERROR(ETIMEDOUT));
967 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
968 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
969 SCTP_PERR(SCTP_ERROR_NO_ERROR));
970 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
971 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
972 return SCTP_DISPOSITION_DELETE_TCB;
976 * The Sender-specific Heartbeat Info field should normally include
977 * information about the sender's current time when this HEARTBEAT
978 * chunk is sent and the destination transport address to which this
979 * HEARTBEAT is sent (see Section 8.3).
982 if (transport->param_flags & SPP_HB_ENABLE) {
983 if (SCTP_DISPOSITION_NOMEM ==
984 sctp_sf_heartbeat(ep, asoc, type, arg,
986 return SCTP_DISPOSITION_NOMEM;
987 /* Set transport error counter and association error counter
988 * when sending heartbeat.
990 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
991 SCTP_TRANSPORT(transport));
993 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
994 SCTP_TRANSPORT(transport));
996 return SCTP_DISPOSITION_CONSUME;
1000 * Process an heartbeat request.
1002 * Section: 8.3 Path Heartbeat
1003 * The receiver of the HEARTBEAT should immediately respond with a
1004 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1005 * from the received HEARTBEAT chunk.
1007 * Verification Tag: 8.5 Verification Tag [Normal verification]
1008 * When receiving an SCTP packet, the endpoint MUST ensure that the
1009 * value in the Verification Tag field of the received SCTP packet
1010 * matches its own Tag. If the received Verification Tag value does not
1011 * match the receiver's own tag value, the receiver shall silently
1012 * discard the packet and shall not process it any further except for
1013 * those cases listed in Section 8.5.1 below.
1016 * (endpoint, asoc, chunk)
1019 * (asoc, reply_msg, msg_up, timers, counters)
1021 * The return value is the disposition of the chunk.
1023 sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1024 const struct sctp_association *asoc,
1025 const sctp_subtype_t type,
1027 sctp_cmd_seq_t *commands)
1029 struct sctp_chunk *chunk = arg;
1030 struct sctp_chunk *reply;
1033 if (!sctp_vtag_verify(chunk, asoc))
1034 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1036 /* Make sure that the HEARTBEAT chunk has a valid length. */
1037 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1038 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1041 /* 8.3 The receiver of the HEARTBEAT should immediately
1042 * respond with a HEARTBEAT ACK that contains the Heartbeat
1043 * Information field copied from the received HEARTBEAT chunk.
1045 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1046 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1047 if (!pskb_pull(chunk->skb, paylen))
1050 reply = sctp_make_heartbeat_ack(asoc, chunk,
1051 chunk->subh.hb_hdr, paylen);
1055 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1056 return SCTP_DISPOSITION_CONSUME;
1059 return SCTP_DISPOSITION_NOMEM;
1063 * Process the returning HEARTBEAT ACK.
1065 * Section: 8.3 Path Heartbeat
1066 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1067 * should clear the error counter of the destination transport
1068 * address to which the HEARTBEAT was sent, and mark the destination
1069 * transport address as active if it is not so marked. The endpoint may
1070 * optionally report to the upper layer when an inactive destination
1071 * address is marked as active due to the reception of the latest
1072 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1073 * clear the association overall error count as well (as defined
1076 * The receiver of the HEARTBEAT ACK should also perform an RTT
1077 * measurement for that destination transport address using the time
1078 * value carried in the HEARTBEAT ACK chunk.
1080 * Verification Tag: 8.5 Verification Tag [Normal verification]
1083 * (endpoint, asoc, chunk)
1086 * (asoc, reply_msg, msg_up, timers, counters)
1088 * The return value is the disposition of the chunk.
1090 sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1091 const struct sctp_association *asoc,
1092 const sctp_subtype_t type,
1094 sctp_cmd_seq_t *commands)
1096 struct sctp_chunk *chunk = arg;
1097 union sctp_addr from_addr;
1098 struct sctp_transport *link;
1099 sctp_sender_hb_info_t *hbinfo;
1100 unsigned long max_interval;
1102 if (!sctp_vtag_verify(chunk, asoc))
1103 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1105 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1106 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1107 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1110 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1111 /* Make sure that the length of the parameter is what we expect */
1112 if (ntohs(hbinfo->param_hdr.length) !=
1113 sizeof(sctp_sender_hb_info_t)) {
1114 return SCTP_DISPOSITION_DISCARD;
1117 from_addr = hbinfo->daddr;
1118 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1120 /* This should never happen, but lets log it if so. */
1121 if (unlikely(!link)) {
1122 if (from_addr.sa.sa_family == AF_INET6) {
1123 if (net_ratelimit())
1125 "%s association %p could not find address "
1129 NIP6(from_addr.v6.sin6_addr));
1131 if (net_ratelimit())
1133 "%s association %p could not find address "
1137 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1139 return SCTP_DISPOSITION_DISCARD;
1142 /* Validate the 64-bit random nonce. */
1143 if (hbinfo->hb_nonce != link->hb_nonce)
1144 return SCTP_DISPOSITION_DISCARD;
1146 max_interval = link->hbinterval + link->rto;
1148 /* Check if the timestamp looks valid. */
1149 if (time_after(hbinfo->sent_at, jiffies) ||
1150 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1151 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1152 "received for transport: %p\n",
1154 return SCTP_DISPOSITION_DISCARD;
1157 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1158 * the HEARTBEAT should clear the error counter of the
1159 * destination transport address to which the HEARTBEAT was
1160 * sent and mark the destination transport address as active if
1161 * it is not so marked.
1163 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1165 return SCTP_DISPOSITION_CONSUME;
1168 /* Helper function to send out an abort for the restart
1171 static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1172 struct sctp_chunk *init,
1173 sctp_cmd_seq_t *commands)
1176 struct sctp_packet *pkt;
1177 union sctp_addr_param *addrparm;
1178 struct sctp_errhdr *errhdr;
1179 struct sctp_endpoint *ep;
1180 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1181 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1183 /* Build the error on the stack. We are way to malloc crazy
1184 * throughout the code today.
1186 errhdr = (struct sctp_errhdr *)buffer;
1187 addrparm = (union sctp_addr_param *)errhdr->variable;
1189 /* Copy into a parm format. */
1190 len = af->to_addr_param(ssa, addrparm);
1191 len += sizeof(sctp_errhdr_t);
1193 errhdr->cause = SCTP_ERROR_RESTART;
1194 errhdr->length = htons(len);
1196 /* Assign to the control socket. */
1197 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1199 /* Association is NULL since this may be a restart attack and we
1200 * want to send back the attacker's vtag.
1202 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1206 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1208 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1210 /* Discard the rest of the inbound packet. */
1211 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1214 /* Even if there is no memory, treat as a failure so
1215 * the packet will get dropped.
1220 /* A restart is occurring, check to make sure no new addresses
1221 * are being added as we may be under a takeover attack.
1223 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1224 const struct sctp_association *asoc,
1225 struct sctp_chunk *init,
1226 sctp_cmd_seq_t *commands)
1228 struct sctp_transport *new_addr, *addr;
1231 /* Implementor's Guide - Sectin 5.2.2
1233 * Before responding the endpoint MUST check to see if the
1234 * unexpected INIT adds new addresses to the association. If new
1235 * addresses are added to the association, the endpoint MUST respond
1239 /* Search through all current addresses and make sure
1240 * we aren't adding any new ones.
1245 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1248 list_for_each_entry(addr, &asoc->peer.transport_addr_list,
1250 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1260 /* If a new address was added, ABORT the sender. */
1261 if (!found && new_addr) {
1262 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
1265 /* Return success if all addresses were found. */
1269 /* Populate the verification/tie tags based on overlapping INIT
1272 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1274 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1275 const struct sctp_association *asoc)
1277 switch (asoc->state) {
1279 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1281 case SCTP_STATE_COOKIE_WAIT:
1282 new_asoc->c.my_vtag = asoc->c.my_vtag;
1283 new_asoc->c.my_ttag = asoc->c.my_vtag;
1284 new_asoc->c.peer_ttag = 0;
1287 case SCTP_STATE_COOKIE_ECHOED:
1288 new_asoc->c.my_vtag = asoc->c.my_vtag;
1289 new_asoc->c.my_ttag = asoc->c.my_vtag;
1290 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1293 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1294 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1297 new_asoc->c.my_ttag = asoc->c.my_vtag;
1298 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1302 /* Other parameters for the endpoint SHOULD be copied from the
1303 * existing parameters of the association (e.g. number of
1304 * outbound streams) into the INIT ACK and cookie.
1306 new_asoc->rwnd = asoc->rwnd;
1307 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1308 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1309 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1313 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1316 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1318 * Returns value representing action to be taken. These action values
1319 * correspond to Action/Description values in RFC 2960, Table 2.
1321 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1322 const struct sctp_association *asoc)
1324 /* In this case, the peer may have restarted. */
1325 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1326 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1327 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1328 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1331 /* Collision case B. */
1332 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1333 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1334 (0 == asoc->c.peer_vtag))) {
1338 /* Collision case D. */
1339 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1340 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1343 /* Collision case C. */
1344 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1345 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1346 (0 == new_asoc->c.my_ttag) &&
1347 (0 == new_asoc->c.peer_ttag))
1350 /* No match to any of the special cases; discard this packet. */
1354 /* Common helper routine for both duplicate and simulataneous INIT
1357 static sctp_disposition_t sctp_sf_do_unexpected_init(
1358 const struct sctp_endpoint *ep,
1359 const struct sctp_association *asoc,
1360 const sctp_subtype_t type,
1361 void *arg, sctp_cmd_seq_t *commands)
1363 sctp_disposition_t retval;
1364 struct sctp_chunk *chunk = arg;
1365 struct sctp_chunk *repl;
1366 struct sctp_association *new_asoc;
1367 struct sctp_chunk *err_chunk;
1368 struct sctp_packet *packet;
1369 sctp_unrecognized_param_t *unk_param;
1373 * An endpoint MUST NOT bundle INIT, INIT ACK or
1374 * SHUTDOWN COMPLETE with any other chunks.
1377 * Furthermore, we require that the receiver of an INIT chunk MUST
1378 * enforce these rules by silently discarding an arriving packet
1379 * with an INIT chunk that is bundled with other chunks.
1381 if (!chunk->singleton)
1382 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1384 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1387 if (chunk->sctp_hdr->vtag != 0)
1388 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1390 /* Make sure that the INIT chunk has a valid length.
1391 * In this case, we generate a protocol violation since we have
1392 * an association established.
1394 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1395 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1397 /* Grab the INIT header. */
1398 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1400 /* Tag the variable length parameters. */
1401 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1403 /* Verify the INIT chunk before processing it. */
1405 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1406 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1408 /* This chunk contains fatal error. It is to be discarded.
1409 * Send an ABORT, with causes if there is any.
1412 packet = sctp_abort_pkt_new(ep, asoc, arg,
1413 (__u8 *)(err_chunk->chunk_hdr) +
1414 sizeof(sctp_chunkhdr_t),
1415 ntohs(err_chunk->chunk_hdr->length) -
1416 sizeof(sctp_chunkhdr_t));
1419 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1420 SCTP_PACKET(packet));
1421 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1422 retval = SCTP_DISPOSITION_CONSUME;
1424 retval = SCTP_DISPOSITION_NOMEM;
1428 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1434 * Other parameters for the endpoint SHOULD be copied from the
1435 * existing parameters of the association (e.g. number of
1436 * outbound streams) into the INIT ACK and cookie.
1437 * FIXME: We are copying parameters from the endpoint not the
1440 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1444 /* In the outbound INIT ACK the endpoint MUST copy its current
1445 * Verification Tag and Peers Verification tag into a reserved
1446 * place (local tie-tag and per tie-tag) within the state cookie.
1448 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1450 (sctp_init_chunk_t *)chunk->chunk_hdr,
1454 /* Make sure no new addresses are being added during the
1455 * restart. Do not do this check for COOKIE-WAIT state,
1456 * since there are no peer addresses to check against.
1457 * Upon return an ABORT will have been sent if needed.
1459 if (!sctp_state(asoc, COOKIE_WAIT)) {
1460 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1462 retval = SCTP_DISPOSITION_CONSUME;
1467 sctp_tietags_populate(new_asoc, asoc);
1469 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1471 /* If there are errors need to be reported for unknown parameters,
1472 * make sure to reserve enough room in the INIT ACK for them.
1476 len = ntohs(err_chunk->chunk_hdr->length) -
1477 sizeof(sctp_chunkhdr_t);
1480 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1483 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1487 /* If there are errors need to be reported for unknown parameters,
1488 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1492 /* Get the "Unrecognized parameter" parameter(s) out of the
1493 * ERROR chunk generated by sctp_verify_init(). Since the
1494 * error cause code for "unknown parameter" and the
1495 * "Unrecognized parameter" type is the same, we can
1496 * construct the parameters in INIT ACK by copying the
1497 * ERROR causes over.
1499 unk_param = (sctp_unrecognized_param_t *)
1500 ((__u8 *)(err_chunk->chunk_hdr) +
1501 sizeof(sctp_chunkhdr_t));
1502 /* Replace the cause code with the "Unrecognized parameter"
1505 sctp_addto_chunk(repl, len, unk_param);
1508 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1509 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1512 * Note: After sending out INIT ACK with the State Cookie parameter,
1513 * "Z" MUST NOT allocate any resources for this new association.
1514 * Otherwise, "Z" will be vulnerable to resource attacks.
1516 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1517 retval = SCTP_DISPOSITION_CONSUME;
1522 retval = SCTP_DISPOSITION_NOMEM;
1525 sctp_association_free(new_asoc);
1528 sctp_chunk_free(err_chunk);
1533 * Handle simultanous INIT.
1534 * This means we started an INIT and then we got an INIT request from
1537 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1538 * This usually indicates an initialization collision, i.e., each
1539 * endpoint is attempting, at about the same time, to establish an
1540 * association with the other endpoint.
1542 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1543 * endpoint MUST respond with an INIT ACK using the same parameters it
1544 * sent in its original INIT chunk (including its Verification Tag,
1545 * unchanged). These original parameters are combined with those from the
1546 * newly received INIT chunk. The endpoint shall also generate a State
1547 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1548 * INIT to calculate the State Cookie.
1550 * After that, the endpoint MUST NOT change its state, the T1-init
1551 * timer shall be left running and the corresponding TCB MUST NOT be
1552 * destroyed. The normal procedures for handling State Cookies when
1553 * a TCB exists will resolve the duplicate INITs to a single association.
1555 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1556 * its Tie-Tags with the Tag information of itself and its peer (see
1557 * section 5.2.2 for a description of the Tie-Tags).
1559 * Verification Tag: Not explicit, but an INIT can not have a valid
1560 * verification tag, so we skip the check.
1563 * (endpoint, asoc, chunk)
1566 * (asoc, reply_msg, msg_up, timers, counters)
1568 * The return value is the disposition of the chunk.
1570 sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1571 const struct sctp_association *asoc,
1572 const sctp_subtype_t type,
1574 sctp_cmd_seq_t *commands)
1576 /* Call helper to do the real work for both simulataneous and
1577 * duplicate INIT chunk handling.
1579 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1583 * Handle duplicated INIT messages. These are usually delayed
1586 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1587 * COOKIE-ECHOED and COOKIE-WAIT
1589 * Unless otherwise stated, upon reception of an unexpected INIT for
1590 * this association, the endpoint shall generate an INIT ACK with a
1591 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1592 * current Verification Tag and peer's Verification Tag into a reserved
1593 * place within the state cookie. We shall refer to these locations as
1594 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1595 * containing this INIT ACK MUST carry a Verification Tag value equal to
1596 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1597 * MUST contain a new Initiation Tag (randomly generated see Section
1598 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1599 * existing parameters of the association (e.g. number of outbound
1600 * streams) into the INIT ACK and cookie.
1602 * After sending out the INIT ACK, the endpoint shall take no further
1603 * actions, i.e., the existing association, including its current state,
1604 * and the corresponding TCB MUST NOT be changed.
1606 * Note: Only when a TCB exists and the association is not in a COOKIE-
1607 * WAIT state are the Tie-Tags populated. For a normal association INIT
1608 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1609 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1610 * State Cookie are populated as specified in section 5.2.1.
1612 * Verification Tag: Not specified, but an INIT has no way of knowing
1613 * what the verification tag could be, so we ignore it.
1616 * (endpoint, asoc, chunk)
1619 * (asoc, reply_msg, msg_up, timers, counters)
1621 * The return value is the disposition of the chunk.
1623 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1624 const struct sctp_association *asoc,
1625 const sctp_subtype_t type,
1627 sctp_cmd_seq_t *commands)
1629 /* Call helper to do the real work for both simulataneous and
1630 * duplicate INIT chunk handling.
1632 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1637 * Unexpected INIT-ACK handler.
1640 * If an INIT ACK received by an endpoint in any state other than the
1641 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1642 * An unexpected INIT ACK usually indicates the processing of an old or
1643 * duplicated INIT chunk.
1645 sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1646 const struct sctp_association *asoc,
1647 const sctp_subtype_t type,
1648 void *arg, sctp_cmd_seq_t *commands)
1650 /* Per the above section, we'll discard the chunk if we have an
1651 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1653 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
1654 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1656 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1659 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1662 * A) In this case, the peer may have restarted.
1664 static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1665 const struct sctp_association *asoc,
1666 struct sctp_chunk *chunk,
1667 sctp_cmd_seq_t *commands,
1668 struct sctp_association *new_asoc)
1670 sctp_init_chunk_t *peer_init;
1671 struct sctp_ulpevent *ev;
1672 struct sctp_chunk *repl;
1673 struct sctp_chunk *err;
1674 sctp_disposition_t disposition;
1676 /* new_asoc is a brand-new association, so these are not yet
1677 * side effects--it is safe to run them here.
1679 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1681 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1682 sctp_source(chunk), peer_init,
1686 /* Make sure no new addresses are being added during the
1687 * restart. Though this is a pretty complicated attack
1688 * since you'd have to get inside the cookie.
1690 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1691 return SCTP_DISPOSITION_CONSUME;
1694 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1695 * the peer has restarted (Action A), it MUST NOT setup a new
1696 * association but instead resend the SHUTDOWN ACK and send an ERROR
1697 * chunk with a "Cookie Received while Shutting Down" error cause to
1700 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1701 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1702 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1704 if (SCTP_DISPOSITION_NOMEM == disposition)
1707 err = sctp_make_op_error(asoc, chunk,
1708 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1711 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1714 return SCTP_DISPOSITION_CONSUME;
1717 /* For now, fail any unsent/unacked data. Consider the optional
1718 * choice of resending of this data.
1720 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1722 repl = sctp_make_cookie_ack(new_asoc, chunk);
1726 /* Report association restart to upper layer. */
1727 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1728 new_asoc->c.sinit_num_ostreams,
1729 new_asoc->c.sinit_max_instreams,
1734 /* Update the content of current association. */
1735 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1736 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1737 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1738 return SCTP_DISPOSITION_CONSUME;
1741 sctp_chunk_free(repl);
1743 return SCTP_DISPOSITION_NOMEM;
1746 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1749 * B) In this case, both sides may be attempting to start an association
1750 * at about the same time but the peer endpoint started its INIT
1751 * after responding to the local endpoint's INIT
1753 /* This case represents an initialization collision. */
1754 static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1755 const struct sctp_association *asoc,
1756 struct sctp_chunk *chunk,
1757 sctp_cmd_seq_t *commands,
1758 struct sctp_association *new_asoc)
1760 sctp_init_chunk_t *peer_init;
1761 struct sctp_chunk *repl;
1763 /* new_asoc is a brand-new association, so these are not yet
1764 * side effects--it is safe to run them here.
1766 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1767 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1768 sctp_source(chunk), peer_init,
1772 /* Update the content of current association. */
1773 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1774 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1775 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1776 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1777 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1779 repl = sctp_make_cookie_ack(new_asoc, chunk);
1783 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1784 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1786 /* RFC 2960 5.1 Normal Establishment of an Association
1788 * D) IMPLEMENTATION NOTE: An implementation may choose to
1789 * send the Communication Up notification to the SCTP user
1790 * upon reception of a valid COOKIE ECHO chunk.
1792 * Sadly, this needs to be implemented as a side-effect, because
1793 * we are not guaranteed to have set the association id of the real
1794 * association and so these notifications need to be delayed until
1795 * the association id is allocated.
1798 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1800 /* Sockets API Draft Section 5.3.1.6
1801 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1802 * delivers this notification to inform the application that of the
1803 * peers requested adaptation layer.
1805 * This also needs to be done as a side effect for the same reason as
1808 if (asoc->peer.adaptation_ind)
1809 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1811 return SCTP_DISPOSITION_CONSUME;
1814 return SCTP_DISPOSITION_NOMEM;
1817 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1820 * C) In this case, the local endpoint's cookie has arrived late.
1821 * Before it arrived, the local endpoint sent an INIT and received an
1822 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1823 * but a new tag of its own.
1825 /* This case represents an initialization collision. */
1826 static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1827 const struct sctp_association *asoc,
1828 struct sctp_chunk *chunk,
1829 sctp_cmd_seq_t *commands,
1830 struct sctp_association *new_asoc)
1832 /* The cookie should be silently discarded.
1833 * The endpoint SHOULD NOT change states and should leave
1834 * any timers running.
1836 return SCTP_DISPOSITION_DISCARD;
1839 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1843 * D) When both local and remote tags match the endpoint should always
1844 * enter the ESTABLISHED state, if it has not already done so.
1846 /* This case represents an initialization collision. */
1847 static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1848 const struct sctp_association *asoc,
1849 struct sctp_chunk *chunk,
1850 sctp_cmd_seq_t *commands,
1851 struct sctp_association *new_asoc)
1853 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1854 struct sctp_chunk *repl;
1856 /* Clarification from Implementor's Guide:
1857 * D) When both local and remote tags match the endpoint should
1858 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1859 * It should stop any cookie timer that may be running and send
1863 /* Don't accidentally move back into established state. */
1864 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1865 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1866 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1867 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1868 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1869 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1870 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1873 /* RFC 2960 5.1 Normal Establishment of an Association
1875 * D) IMPLEMENTATION NOTE: An implementation may choose
1876 * to send the Communication Up notification to the
1877 * SCTP user upon reception of a valid COOKIE
1880 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1882 asoc->c.sinit_num_ostreams,
1883 asoc->c.sinit_max_instreams,
1888 /* Sockets API Draft Section 5.3.1.6
1889 * When a peer sends a Adaptation Layer Indication parameter,
1890 * SCTP delivers this notification to inform the application
1891 * that of the peers requested adaptation layer.
1893 if (asoc->peer.adaptation_ind) {
1894 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1901 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1903 repl = sctp_make_cookie_ack(new_asoc, chunk);
1908 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1911 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1912 SCTP_ULPEVENT(ai_ev));
1914 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1915 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1917 return SCTP_DISPOSITION_CONSUME;
1921 sctp_ulpevent_free(ai_ev);
1923 sctp_ulpevent_free(ev);
1924 return SCTP_DISPOSITION_NOMEM;
1928 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1929 * chunk was retransmitted and then delayed in the network.
1931 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1933 * Verification Tag: None. Do cookie validation.
1936 * (endpoint, asoc, chunk)
1939 * (asoc, reply_msg, msg_up, timers, counters)
1941 * The return value is the disposition of the chunk.
1943 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1944 const struct sctp_association *asoc,
1945 const sctp_subtype_t type,
1947 sctp_cmd_seq_t *commands)
1949 sctp_disposition_t retval;
1950 struct sctp_chunk *chunk = arg;
1951 struct sctp_association *new_asoc;
1954 struct sctp_chunk *err_chk_p;
1956 /* Make sure that the chunk has a valid length from the protocol
1957 * perspective. In this case check to make sure we have at least
1958 * enough for the chunk header. Cookie length verification is
1961 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1962 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1965 /* "Decode" the chunk. We have no optional parameters so we
1966 * are in good shape.
1968 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
1969 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1970 sizeof(sctp_chunkhdr_t)))
1973 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1974 * of a duplicate COOKIE ECHO match the Verification Tags of the
1975 * current association, consider the State Cookie valid even if
1976 * the lifespan is exceeded.
1978 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1982 * If the re-build failed, what is the proper error path
1985 * [We should abort the association. --piggy]
1988 /* FIXME: Several errors are possible. A bad cookie should
1989 * be silently discarded, but think about logging it too.
1992 case -SCTP_IERROR_NOMEM:
1995 case -SCTP_IERROR_STALE_COOKIE:
1996 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1998 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1999 case -SCTP_IERROR_BAD_SIG:
2001 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2005 /* Compare the tie_tag in cookie with the verification tag of
2006 * current association.
2008 action = sctp_tietags_compare(new_asoc, asoc);
2011 case 'A': /* Association restart. */
2012 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2016 case 'B': /* Collision case B. */
2017 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2021 case 'C': /* Collision case C. */
2022 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2026 case 'D': /* Collision case D. */
2027 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2031 default: /* Discard packet for all others. */
2032 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2036 /* Delete the tempory new association. */
2037 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2038 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2043 return SCTP_DISPOSITION_NOMEM;
2047 * Process an ABORT. (SHUTDOWN-PENDING state)
2049 * See sctp_sf_do_9_1_abort().
2051 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2052 const struct sctp_endpoint *ep,
2053 const struct sctp_association *asoc,
2054 const sctp_subtype_t type,
2056 sctp_cmd_seq_t *commands)
2058 struct sctp_chunk *chunk = arg;
2060 if (!sctp_vtag_verify_either(chunk, asoc))
2061 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2063 /* Make sure that the ABORT chunk has a valid length.
2064 * Since this is an ABORT chunk, we have to discard it
2065 * because of the following text:
2066 * RFC 2960, Section 3.3.7
2067 * If an endpoint receives an ABORT with a format error or for an
2068 * association that doesn't exist, it MUST silently discard it.
2069 * Becasue the length is "invalid", we can't really discard just
2070 * as we do not know its true length. So, to be safe, discard the
2073 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2074 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2076 /* ADD-IP: Special case for ABORT chunks
2077 * F4) One special consideration is that ABORT Chunks arriving
2078 * destined to the IP address being deleted MUST be
2079 * ignored (see Section 5.3.1 for further details).
2081 if (SCTP_ADDR_DEL ==
2082 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2083 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2085 /* Stop the T5-shutdown guard timer. */
2086 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2087 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2089 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2093 * Process an ABORT. (SHUTDOWN-SENT state)
2095 * See sctp_sf_do_9_1_abort().
2097 sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2098 const struct sctp_association *asoc,
2099 const sctp_subtype_t type,
2101 sctp_cmd_seq_t *commands)
2103 struct sctp_chunk *chunk = arg;
2105 if (!sctp_vtag_verify_either(chunk, asoc))
2106 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2108 /* Make sure that the ABORT chunk has a valid length.
2109 * Since this is an ABORT chunk, we have to discard it
2110 * because of the following text:
2111 * RFC 2960, Section 3.3.7
2112 * If an endpoint receives an ABORT with a format error or for an
2113 * association that doesn't exist, it MUST silently discard it.
2114 * Becasue the length is "invalid", we can't really discard just
2115 * as we do not know its true length. So, to be safe, discard the
2118 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2119 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2121 /* ADD-IP: Special case for ABORT chunks
2122 * F4) One special consideration is that ABORT Chunks arriving
2123 * destined to the IP address being deleted MUST be
2124 * ignored (see Section 5.3.1 for further details).
2126 if (SCTP_ADDR_DEL ==
2127 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2128 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2130 /* Stop the T2-shutdown timer. */
2131 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2132 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2134 /* Stop the T5-shutdown guard timer. */
2135 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2136 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2138 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2142 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2144 * See sctp_sf_do_9_1_abort().
2146 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2147 const struct sctp_endpoint *ep,
2148 const struct sctp_association *asoc,
2149 const sctp_subtype_t type,
2151 sctp_cmd_seq_t *commands)
2153 /* The same T2 timer, so we should be able to use
2154 * common function with the SHUTDOWN-SENT state.
2156 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2160 * Handle an Error received in COOKIE_ECHOED state.
2162 * Only handle the error type of stale COOKIE Error, the other errors will
2166 * (endpoint, asoc, chunk)
2169 * (asoc, reply_msg, msg_up, timers, counters)
2171 * The return value is the disposition of the chunk.
2173 sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2174 const struct sctp_association *asoc,
2175 const sctp_subtype_t type,
2177 sctp_cmd_seq_t *commands)
2179 struct sctp_chunk *chunk = arg;
2182 if (!sctp_vtag_verify(chunk, asoc))
2183 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2185 /* Make sure that the ERROR chunk has a valid length.
2186 * The parameter walking depends on this as well.
2188 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2189 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2192 /* Process the error here */
2193 /* FUTURE FIXME: When PR-SCTP related and other optional
2194 * parms are emitted, this will have to change to handle multiple
2197 sctp_walk_errors(err, chunk->chunk_hdr) {
2198 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2199 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2203 /* It is possible to have malformed error causes, and that
2204 * will cause us to end the walk early. However, since
2205 * we are discarding the packet, there should be no adverse
2208 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2212 * Handle a Stale COOKIE Error
2214 * Section: 5.2.6 Handle Stale COOKIE Error
2215 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2216 * one of the following three alternatives.
2218 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2219 * Preservative parameter requesting an extension to the lifetime of
2220 * the State Cookie. When calculating the time extension, an
2221 * implementation SHOULD use the RTT information measured based on the
2222 * previous COOKIE ECHO / ERROR exchange, and should add no more
2223 * than 1 second beyond the measured RTT, due to long State Cookie
2224 * lifetimes making the endpoint more subject to a replay attack.
2226 * Verification Tag: Not explicit, but safe to ignore.
2229 * (endpoint, asoc, chunk)
2232 * (asoc, reply_msg, msg_up, timers, counters)
2234 * The return value is the disposition of the chunk.
2236 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2237 const struct sctp_association *asoc,
2238 const sctp_subtype_t type,
2240 sctp_cmd_seq_t *commands)
2242 struct sctp_chunk *chunk = arg;
2244 sctp_cookie_preserve_param_t bht;
2246 struct sctp_chunk *reply;
2247 struct sctp_bind_addr *bp;
2248 int attempts = asoc->init_err_counter + 1;
2250 if (attempts > asoc->max_init_attempts) {
2251 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2252 SCTP_ERROR(ETIMEDOUT));
2253 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2254 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2255 return SCTP_DISPOSITION_DELETE_TCB;
2258 err = (sctp_errhdr_t *)(chunk->skb->data);
2260 /* When calculating the time extension, an implementation
2261 * SHOULD use the RTT information measured based on the
2262 * previous COOKIE ECHO / ERROR exchange, and should add no
2263 * more than 1 second beyond the measured RTT, due to long
2264 * State Cookie lifetimes making the endpoint more subject to
2266 * Measure of Staleness's unit is usec. (1/1000000 sec)
2267 * Suggested Cookie Life-span Increment's unit is msec.
2269 * In general, if you use the suggested cookie life, the value
2270 * found in the field of measure of staleness should be doubled
2271 * to give ample time to retransmit the new cookie and thus
2272 * yield a higher probability of success on the reattempt.
2274 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2275 stale = (stale * 2) / 1000;
2277 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2278 bht.param_hdr.length = htons(sizeof(bht));
2279 bht.lifespan_increment = htonl(stale);
2281 /* Build that new INIT chunk. */
2282 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2283 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2287 sctp_addto_chunk(reply, sizeof(bht), &bht);
2289 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2290 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2292 /* Stop pending T3-rtx and heartbeat timers */
2293 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2294 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2296 /* Delete non-primary peer ip addresses since we are transitioning
2297 * back to the COOKIE-WAIT state
2299 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2301 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2304 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2305 SCTP_TRANSPORT(asoc->peer.primary_path));
2307 /* Cast away the const modifier, as we want to just
2308 * rerun it through as a sideffect.
2310 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2312 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2313 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2314 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2315 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2316 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2317 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2319 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2321 return SCTP_DISPOSITION_CONSUME;
2324 return SCTP_DISPOSITION_NOMEM;
2331 * After checking the Verification Tag, the receiving endpoint shall
2332 * remove the association from its record, and shall report the
2333 * termination to its upper layer.
2335 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2336 * B) Rules for packet carrying ABORT:
2338 * - The endpoint shall always fill in the Verification Tag field of the
2339 * outbound packet with the destination endpoint's tag value if it
2342 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2343 * MUST follow the procedure described in Section 8.4.
2345 * - The receiver MUST accept the packet if the Verification Tag
2346 * matches either its own tag, OR the tag of its peer. Otherwise, the
2347 * receiver MUST silently discard the packet and take no further
2351 * (endpoint, asoc, chunk)
2354 * (asoc, reply_msg, msg_up, timers, counters)
2356 * The return value is the disposition of the chunk.
2358 sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2359 const struct sctp_association *asoc,
2360 const sctp_subtype_t type,
2362 sctp_cmd_seq_t *commands)
2364 struct sctp_chunk *chunk = arg;
2366 if (!sctp_vtag_verify_either(chunk, asoc))
2367 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2369 /* Make sure that the ABORT chunk has a valid length.
2370 * Since this is an ABORT chunk, we have to discard it
2371 * because of the following text:
2372 * RFC 2960, Section 3.3.7
2373 * If an endpoint receives an ABORT with a format error or for an
2374 * association that doesn't exist, it MUST silently discard it.
2375 * Becasue the length is "invalid", we can't really discard just
2376 * as we do not know its true length. So, to be safe, discard the
2379 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2380 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2382 /* ADD-IP: Special case for ABORT chunks
2383 * F4) One special consideration is that ABORT Chunks arriving
2384 * destined to the IP address being deleted MUST be
2385 * ignored (see Section 5.3.1 for further details).
2387 if (SCTP_ADDR_DEL ==
2388 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2389 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2391 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2394 static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2395 const struct sctp_association *asoc,
2396 const sctp_subtype_t type,
2398 sctp_cmd_seq_t *commands)
2400 struct sctp_chunk *chunk = arg;
2402 __be16 error = SCTP_ERROR_NO_ERROR;
2404 /* See if we have an error cause code in the chunk. */
2405 len = ntohs(chunk->chunk_hdr->length);
2406 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2407 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2409 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2410 /* ASSOC_FAILED will DELETE_TCB. */
2411 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2412 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2413 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2415 return SCTP_DISPOSITION_ABORT;
2419 * Process an ABORT. (COOKIE-WAIT state)
2421 * See sctp_sf_do_9_1_abort() above.
2423 sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2424 const struct sctp_association *asoc,
2425 const sctp_subtype_t type,
2427 sctp_cmd_seq_t *commands)
2429 struct sctp_chunk *chunk = arg;
2431 __be16 error = SCTP_ERROR_NO_ERROR;
2433 if (!sctp_vtag_verify_either(chunk, asoc))
2434 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2436 /* Make sure that the ABORT chunk has a valid length.
2437 * Since this is an ABORT chunk, we have to discard it
2438 * because of the following text:
2439 * RFC 2960, Section 3.3.7
2440 * If an endpoint receives an ABORT with a format error or for an
2441 * association that doesn't exist, it MUST silently discard it.
2442 * Becasue the length is "invalid", we can't really discard just
2443 * as we do not know its true length. So, to be safe, discard the
2446 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2447 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2449 /* See if we have an error cause code in the chunk. */
2450 len = ntohs(chunk->chunk_hdr->length);
2451 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2452 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2454 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2459 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2461 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2462 const struct sctp_association *asoc,
2463 const sctp_subtype_t type,
2465 sctp_cmd_seq_t *commands)
2467 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2469 (struct sctp_transport *)arg);
2473 * Process an ABORT. (COOKIE-ECHOED state)
2475 sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2476 const struct sctp_association *asoc,
2477 const sctp_subtype_t type,
2479 sctp_cmd_seq_t *commands)
2481 /* There is a single T1 timer, so we should be able to use
2482 * common function with the COOKIE-WAIT state.
2484 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2488 * Stop T1 timer and abort association with "INIT failed".
2490 * This is common code called by several sctp_sf_*_abort() functions above.
2492 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
2493 __be16 error, int sk_err,
2494 const struct sctp_association *asoc,
2495 struct sctp_transport *transport)
2497 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2498 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2499 SCTP_STATE(SCTP_STATE_CLOSED));
2500 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2501 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2502 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2503 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2504 /* CMD_INIT_FAILED will DELETE_TCB. */
2505 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2507 return SCTP_DISPOSITION_ABORT;
2511 * sctp_sf_do_9_2_shut
2514 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2515 * - enter the SHUTDOWN-RECEIVED state,
2517 * - stop accepting new data from its SCTP user
2519 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2520 * that all its outstanding DATA chunks have been received by the
2523 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2524 * send a SHUTDOWN in response to a ULP request. And should discard
2525 * subsequent SHUTDOWN chunks.
2527 * If there are still outstanding DATA chunks left, the SHUTDOWN
2528 * receiver shall continue to follow normal data transmission
2529 * procedures defined in Section 6 until all outstanding DATA chunks
2530 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2531 * new data from its SCTP user.
2533 * Verification Tag: 8.5 Verification Tag [Normal verification]
2536 * (endpoint, asoc, chunk)
2539 * (asoc, reply_msg, msg_up, timers, counters)
2541 * The return value is the disposition of the chunk.
2543 sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2544 const struct sctp_association *asoc,
2545 const sctp_subtype_t type,
2547 sctp_cmd_seq_t *commands)
2549 struct sctp_chunk *chunk = arg;
2550 sctp_shutdownhdr_t *sdh;
2551 sctp_disposition_t disposition;
2552 struct sctp_ulpevent *ev;
2554 if (!sctp_vtag_verify(chunk, asoc))
2555 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2557 /* Make sure that the SHUTDOWN chunk has a valid length. */
2558 if (!sctp_chunk_length_valid(chunk,
2559 sizeof(struct sctp_shutdown_chunk_t)))
2560 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2563 /* Convert the elaborate header. */
2564 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2565 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2566 chunk->subh.shutdown_hdr = sdh;
2568 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2569 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2570 * inform the application that it should cease sending data.
2572 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2574 disposition = SCTP_DISPOSITION_NOMEM;
2577 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2579 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2580 * - enter the SHUTDOWN-RECEIVED state,
2581 * - stop accepting new data from its SCTP user
2583 * [This is implicit in the new state.]
2585 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2586 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2587 disposition = SCTP_DISPOSITION_CONSUME;
2589 if (sctp_outq_is_empty(&asoc->outqueue)) {
2590 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2594 if (SCTP_DISPOSITION_NOMEM == disposition)
2597 /* - verify, by checking the Cumulative TSN Ack field of the
2598 * chunk, that all its outstanding DATA chunks have been
2599 * received by the SHUTDOWN sender.
2601 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2602 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2609 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2610 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2611 * transport addresses (either in the IP addresses or in the INIT chunk)
2612 * that belong to this association, it should discard the INIT chunk and
2613 * retransmit the SHUTDOWN ACK chunk.
2615 sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2616 const struct sctp_association *asoc,
2617 const sctp_subtype_t type,
2619 sctp_cmd_seq_t *commands)
2621 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2622 struct sctp_chunk *reply;
2624 /* Make sure that the chunk has a valid length */
2625 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2626 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2629 /* Since we are not going to really process this INIT, there
2630 * is no point in verifying chunk boundries. Just generate
2633 reply = sctp_make_shutdown_ack(asoc, chunk);
2637 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2638 * the T2-SHUTDOWN timer.
2640 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2642 /* and restart the T2-shutdown timer. */
2643 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2644 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2646 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2648 return SCTP_DISPOSITION_CONSUME;
2650 return SCTP_DISPOSITION_NOMEM;
2654 * sctp_sf_do_ecn_cwr
2656 * Section: Appendix A: Explicit Congestion Notification
2660 * RFC 2481 details a specific bit for a sender to send in the header of
2661 * its next outbound TCP segment to indicate to its peer that it has
2662 * reduced its congestion window. This is termed the CWR bit. For
2663 * SCTP the same indication is made by including the CWR chunk.
2664 * This chunk contains one data element, i.e. the TSN number that
2665 * was sent in the ECNE chunk. This element represents the lowest
2666 * TSN number in the datagram that was originally marked with the
2669 * Verification Tag: 8.5 Verification Tag [Normal verification]
2671 * (endpoint, asoc, chunk)
2674 * (asoc, reply_msg, msg_up, timers, counters)
2676 * The return value is the disposition of the chunk.
2678 sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2679 const struct sctp_association *asoc,
2680 const sctp_subtype_t type,
2682 sctp_cmd_seq_t *commands)
2685 struct sctp_chunk *chunk = arg;
2688 if (!sctp_vtag_verify(chunk, asoc))
2689 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2691 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2692 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2695 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2696 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2698 lowest_tsn = ntohl(cwr->lowest_tsn);
2700 /* Does this CWR ack the last sent congestion notification? */
2701 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2702 /* Stop sending ECNE. */
2703 sctp_add_cmd_sf(commands,
2705 SCTP_U32(lowest_tsn));
2707 return SCTP_DISPOSITION_CONSUME;
2713 * Section: Appendix A: Explicit Congestion Notification
2717 * RFC 2481 details a specific bit for a receiver to send back in its
2718 * TCP acknowledgements to notify the sender of the Congestion
2719 * Experienced (CE) bit having arrived from the network. For SCTP this
2720 * same indication is made by including the ECNE chunk. This chunk
2721 * contains one data element, i.e. the lowest TSN associated with the IP
2722 * datagram marked with the CE bit.....
2724 * Verification Tag: 8.5 Verification Tag [Normal verification]
2726 * (endpoint, asoc, chunk)
2729 * (asoc, reply_msg, msg_up, timers, counters)
2731 * The return value is the disposition of the chunk.
2733 sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2734 const struct sctp_association *asoc,
2735 const sctp_subtype_t type,
2737 sctp_cmd_seq_t *commands)
2739 sctp_ecnehdr_t *ecne;
2740 struct sctp_chunk *chunk = arg;
2742 if (!sctp_vtag_verify(chunk, asoc))
2743 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2745 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2746 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2749 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2750 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2752 /* If this is a newer ECNE than the last CWR packet we sent out */
2753 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2754 SCTP_U32(ntohl(ecne->lowest_tsn)));
2756 return SCTP_DISPOSITION_CONSUME;
2760 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2762 * The SCTP endpoint MUST always acknowledge the reception of each valid
2765 * The guidelines on delayed acknowledgement algorithm specified in
2766 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2767 * acknowledgement SHOULD be generated for at least every second packet
2768 * (not every second DATA chunk) received, and SHOULD be generated within
2769 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2770 * situations it may be beneficial for an SCTP transmitter to be more
2771 * conservative than the algorithms detailed in this document allow.
2772 * However, an SCTP transmitter MUST NOT be more aggressive than the
2773 * following algorithms allow.
2775 * A SCTP receiver MUST NOT generate more than one SACK for every
2776 * incoming packet, other than to update the offered window as the
2777 * receiving application consumes new data.
2779 * Verification Tag: 8.5 Verification Tag [Normal verification]
2782 * (endpoint, asoc, chunk)
2785 * (asoc, reply_msg, msg_up, timers, counters)
2787 * The return value is the disposition of the chunk.
2789 sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2790 const struct sctp_association *asoc,
2791 const sctp_subtype_t type,
2793 sctp_cmd_seq_t *commands)
2795 struct sctp_chunk *chunk = arg;
2798 if (!sctp_vtag_verify(chunk, asoc)) {
2799 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2801 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2804 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2805 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2808 error = sctp_eat_data(asoc, chunk, commands );
2810 case SCTP_IERROR_NO_ERROR:
2812 case SCTP_IERROR_HIGH_TSN:
2813 case SCTP_IERROR_BAD_STREAM:
2814 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2815 goto discard_noforce;
2816 case SCTP_IERROR_DUP_TSN:
2817 case SCTP_IERROR_IGNORE_TSN:
2818 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2820 case SCTP_IERROR_NO_DATA:
2826 if (asoc->autoclose) {
2827 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2828 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2831 /* If this is the last chunk in a packet, we need to count it
2832 * toward sack generation. Note that we need to SACK every
2833 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2834 * THEM. We elect to NOT generate SACK's if the chunk fails
2835 * the verification tag test.
2837 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2839 * The SCTP endpoint MUST always acknowledge the reception of
2840 * each valid DATA chunk.
2842 * The guidelines on delayed acknowledgement algorithm
2843 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2844 * Specifically, an acknowledgement SHOULD be generated for at
2845 * least every second packet (not every second DATA chunk)
2846 * received, and SHOULD be generated within 200 ms of the
2847 * arrival of any unacknowledged DATA chunk. In some
2848 * situations it may be beneficial for an SCTP transmitter to
2849 * be more conservative than the algorithms detailed in this
2850 * document allow. However, an SCTP transmitter MUST NOT be
2851 * more aggressive than the following algorithms allow.
2853 if (chunk->end_of_packet)
2854 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2856 return SCTP_DISPOSITION_CONSUME;
2859 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2861 * When a packet arrives with duplicate DATA chunk(s) and with
2862 * no new DATA chunk(s), the endpoint MUST immediately send a
2863 * SACK with no delay. If a packet arrives with duplicate
2864 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2865 * MAY immediately send a SACK. Normally receipt of duplicate
2866 * DATA chunks will occur when the original SACK chunk was lost
2867 * and the peer's RTO has expired. The duplicate TSN number(s)
2868 * SHOULD be reported in the SACK as duplicate.
2870 /* In our case, we split the MAY SACK advice up whether or not
2871 * the last chunk is a duplicate.'
2873 if (chunk->end_of_packet)
2874 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2875 return SCTP_DISPOSITION_DISCARD;
2878 if (chunk->end_of_packet)
2879 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2881 return SCTP_DISPOSITION_DISCARD;
2883 return SCTP_DISPOSITION_CONSUME;
2888 * sctp_sf_eat_data_fast_4_4
2891 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2892 * DATA chunks without delay.
2894 * Verification Tag: 8.5 Verification Tag [Normal verification]
2896 * (endpoint, asoc, chunk)
2899 * (asoc, reply_msg, msg_up, timers, counters)
2901 * The return value is the disposition of the chunk.
2903 sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2904 const struct sctp_association *asoc,
2905 const sctp_subtype_t type,
2907 sctp_cmd_seq_t *commands)
2909 struct sctp_chunk *chunk = arg;
2912 if (!sctp_vtag_verify(chunk, asoc)) {
2913 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2915 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2918 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2919 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2922 error = sctp_eat_data(asoc, chunk, commands );
2924 case SCTP_IERROR_NO_ERROR:
2925 case SCTP_IERROR_HIGH_TSN:
2926 case SCTP_IERROR_DUP_TSN:
2927 case SCTP_IERROR_IGNORE_TSN:
2928 case SCTP_IERROR_BAD_STREAM:
2930 case SCTP_IERROR_NO_DATA:
2936 /* Go a head and force a SACK, since we are shutting down. */
2938 /* Implementor's Guide.
2940 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2941 * respond to each received packet containing one or more DATA chunk(s)
2942 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2944 if (chunk->end_of_packet) {
2945 /* We must delay the chunk creation since the cumulative
2946 * TSN has not been updated yet.
2948 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2949 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2950 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2951 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2955 return SCTP_DISPOSITION_CONSUME;
2959 * Section: 6.2 Processing a Received SACK
2960 * D) Any time a SACK arrives, the endpoint performs the following:
2962 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2963 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2964 * increasing, a SACK whose Cumulative TSN Ack is less than the
2965 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2967 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2968 * of bytes still outstanding after processing the Cumulative TSN Ack
2969 * and the Gap Ack Blocks.
2971 * iii) If the SACK is missing a TSN that was previously
2972 * acknowledged via a Gap Ack Block (e.g., the data receiver
2973 * reneged on the data), then mark the corresponding DATA chunk
2974 * as available for retransmit: Mark it as missing for fast
2975 * retransmit as described in Section 7.2.4 and if no retransmit
2976 * timer is running for the destination address to which the DATA
2977 * chunk was originally transmitted, then T3-rtx is started for
2978 * that destination address.
2980 * Verification Tag: 8.5 Verification Tag [Normal verification]
2983 * (endpoint, asoc, chunk)
2986 * (asoc, reply_msg, msg_up, timers, counters)
2988 * The return value is the disposition of the chunk.
2990 sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2991 const struct sctp_association *asoc,
2992 const sctp_subtype_t type,
2994 sctp_cmd_seq_t *commands)
2996 struct sctp_chunk *chunk = arg;
2997 sctp_sackhdr_t *sackh;
3000 if (!sctp_vtag_verify(chunk, asoc))
3001 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3003 /* Make sure that the SACK chunk has a valid length. */
3004 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3005 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3008 /* Pull the SACK chunk from the data buffer */
3009 sackh = sctp_sm_pull_sack(chunk);
3010 /* Was this a bogus SACK? */
3012 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3013 chunk->subh.sack_hdr = sackh;
3014 ctsn = ntohl(sackh->cum_tsn_ack);
3016 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3017 * Ack Point, then drop the SACK. Since Cumulative TSN
3018 * Ack is monotonically increasing, a SACK whose
3019 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3020 * Point indicates an out-of-order SACK.
3022 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3023 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3024 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3025 return SCTP_DISPOSITION_DISCARD;
3028 /* If Cumulative TSN Ack beyond the max tsn currently
3029 * send, terminating the association and respond to the
3030 * sender with an ABORT.
3032 if (!TSN_lt(ctsn, asoc->next_tsn))
3033 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3035 /* Return this SACK for further processing. */
3036 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3038 /* Note: We do the rest of the work on the PROCESS_SACK
3041 return SCTP_DISPOSITION_CONSUME;
3045 * Generate an ABORT in response to a packet.
3047 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3049 * 8) The receiver should respond to the sender of the OOTB packet with
3050 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3051 * MUST fill in the Verification Tag field of the outbound packet
3052 * with the value found in the Verification Tag field of the OOTB
3053 * packet and set the T-bit in the Chunk Flags to indicate that the
3054 * Verification Tag is reflected. After sending this ABORT, the
3055 * receiver of the OOTB packet shall discard the OOTB packet and take
3056 * no further action.
3060 * The return value is the disposition of the chunk.
3062 static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
3063 const struct sctp_association *asoc,
3064 const sctp_subtype_t type,
3066 sctp_cmd_seq_t *commands)
3068 struct sctp_packet *packet = NULL;
3069 struct sctp_chunk *chunk = arg;
3070 struct sctp_chunk *abort;
3072 packet = sctp_ootb_pkt_new(asoc, chunk);
3075 /* Make an ABORT. The T bit will be set if the asoc
3078 abort = sctp_make_abort(asoc, chunk, 0);
3080 sctp_ootb_pkt_free(packet);
3081 return SCTP_DISPOSITION_NOMEM;
3084 /* Reflect vtag if T-Bit is set */
3085 if (sctp_test_T_bit(abort))
3086 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3088 /* Set the skb to the belonging sock for accounting. */
3089 abort->skb->sk = ep->base.sk;
3091 sctp_packet_append_chunk(packet, abort);
3093 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3094 SCTP_PACKET(packet));
3096 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3098 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3099 return SCTP_DISPOSITION_CONSUME;
3102 return SCTP_DISPOSITION_NOMEM;
3106 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3107 * event as ULP notification for each cause included in the chunk.
3109 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3111 * The return value is the disposition of the chunk.
3113 sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3114 const struct sctp_association *asoc,
3115 const sctp_subtype_t type,
3117 sctp_cmd_seq_t *commands)
3119 struct sctp_chunk *chunk = arg;
3120 struct sctp_ulpevent *ev;
3122 if (!sctp_vtag_verify(chunk, asoc))
3123 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3125 /* Make sure that the ERROR chunk has a valid length. */
3126 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3127 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3130 while (chunk->chunk_end > chunk->skb->data) {
3131 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
3136 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3138 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3141 return SCTP_DISPOSITION_CONSUME;
3144 return SCTP_DISPOSITION_NOMEM;
3148 * Process an inbound SHUTDOWN ACK.
3151 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3152 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3153 * peer, and remove all record of the association.
3155 * The return value is the disposition.
3157 sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3158 const struct sctp_association *asoc,
3159 const sctp_subtype_t type,
3161 sctp_cmd_seq_t *commands)
3163 struct sctp_chunk *chunk = arg;
3164 struct sctp_chunk *reply;
3165 struct sctp_ulpevent *ev;
3167 if (!sctp_vtag_verify(chunk, asoc))
3168 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3170 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3171 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3172 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3174 /* 10.2 H) SHUTDOWN COMPLETE notification
3176 * When SCTP completes the shutdown procedures (section 9.2) this
3177 * notification is passed to the upper layer.
3179 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3180 0, 0, 0, NULL, GFP_ATOMIC);
3184 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3185 reply = sctp_make_shutdown_complete(asoc, chunk);
3189 /* Do all the commands now (after allocation), so that we
3190 * have consistent state if memory allocation failes
3192 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3194 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3195 * stop the T2-shutdown timer,
3197 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3198 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3200 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3201 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3203 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3204 SCTP_STATE(SCTP_STATE_CLOSED));
3205 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3206 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3207 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3209 /* ...and remove all record of the association. */
3210 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3211 return SCTP_DISPOSITION_DELETE_TCB;
3214 sctp_ulpevent_free(ev);
3216 return SCTP_DISPOSITION_NOMEM;
3220 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3222 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3223 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3224 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3225 * packet must fill in the Verification Tag field of the outbound
3226 * packet with the Verification Tag received in the SHUTDOWN ACK and
3227 * set the T-bit in the Chunk Flags to indicate that the Verification
3230 * 8) The receiver should respond to the sender of the OOTB packet with
3231 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3232 * MUST fill in the Verification Tag field of the outbound packet
3233 * with the value found in the Verification Tag field of the OOTB
3234 * packet and set the T-bit in the Chunk Flags to indicate that the
3235 * Verification Tag is reflected. After sending this ABORT, the
3236 * receiver of the OOTB packet shall discard the OOTB packet and take
3237 * no further action.
3239 sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3240 const struct sctp_association *asoc,
3241 const sctp_subtype_t type,
3243 sctp_cmd_seq_t *commands)
3245 struct sctp_chunk *chunk = arg;
3246 struct sk_buff *skb = chunk->skb;
3247 sctp_chunkhdr_t *ch;
3249 int ootb_shut_ack = 0;
3251 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3253 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3255 /* Report violation if the chunk is less then minimal */
3256 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3257 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3260 /* Now that we know we at least have a chunk header,
3261 * do things that are type appropriate.
3263 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3266 /* RFC 2960, Section 3.3.7
3267 * Moreover, under any circumstances, an endpoint that
3268 * receives an ABORT MUST NOT respond to that ABORT by
3269 * sending an ABORT of its own.
3271 if (SCTP_CID_ABORT == ch->type)
3272 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3274 /* Report violation if chunk len overflows */
3275 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3276 if (ch_end > skb_tail_pointer(skb))
3277 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3280 ch = (sctp_chunkhdr_t *) ch_end;
3281 } while (ch_end < skb_tail_pointer(skb));
3284 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3286 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3290 * Handle an "Out of the blue" SHUTDOWN ACK.
3292 * Section: 8.4 5, sctpimpguide 2.41.
3294 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3295 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3296 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3297 * packet must fill in the Verification Tag field of the outbound
3298 * packet with the Verification Tag received in the SHUTDOWN ACK and
3299 * set the T-bit in the Chunk Flags to indicate that the Verification
3303 * (endpoint, asoc, type, arg, commands)
3306 * (sctp_disposition_t)
3308 * The return value is the disposition of the chunk.
3310 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3311 const struct sctp_association *asoc,
3312 const sctp_subtype_t type,
3314 sctp_cmd_seq_t *commands)
3316 struct sctp_packet *packet = NULL;
3317 struct sctp_chunk *chunk = arg;
3318 struct sctp_chunk *shut;
3320 packet = sctp_ootb_pkt_new(asoc, chunk);
3323 /* Make an SHUTDOWN_COMPLETE.
3324 * The T bit will be set if the asoc is NULL.
3326 shut = sctp_make_shutdown_complete(asoc, chunk);
3328 sctp_ootb_pkt_free(packet);
3329 return SCTP_DISPOSITION_NOMEM;
3332 /* Reflect vtag if T-Bit is set */
3333 if (sctp_test_T_bit(shut))
3334 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3336 /* Set the skb to the belonging sock for accounting. */
3337 shut->skb->sk = ep->base.sk;
3339 sctp_packet_append_chunk(packet, shut);
3341 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3342 SCTP_PACKET(packet));
3344 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3346 /* If the chunk length is invalid, we don't want to process
3347 * the reset of the packet.
3349 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3350 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3352 /* We need to discard the rest of the packet to prevent
3353 * potential bomming attacks from additional bundled chunks.
3354 * This is documented in SCTP Threats ID.
3356 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3359 return SCTP_DISPOSITION_NOMEM;
3363 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3365 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3366 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3367 * procedures in section 8.4 SHOULD be followed, in other words it
3368 * should be treated as an Out Of The Blue packet.
3369 * [This means that we do NOT check the Verification Tag on these
3373 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3374 const struct sctp_association *asoc,
3375 const sctp_subtype_t type,
3377 sctp_cmd_seq_t *commands)
3379 struct sctp_chunk *chunk = arg;
3381 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3382 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3383 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3386 /* Although we do have an association in this case, it corresponds
3387 * to a restarted association. So the packet is treated as an OOTB
3388 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3389 * called with a NULL association.
3391 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3394 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3395 sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3396 const struct sctp_association *asoc,
3397 const sctp_subtype_t type, void *arg,
3398 sctp_cmd_seq_t *commands)
3400 struct sctp_chunk *chunk = arg;
3401 struct sctp_chunk *asconf_ack = NULL;
3402 struct sctp_paramhdr *err_param = NULL;
3403 sctp_addiphdr_t *hdr;
3404 union sctp_addr_param *addr_param;
3408 if (!sctp_vtag_verify(chunk, asoc)) {
3409 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3411 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3414 /* ADD-IP: Section 4.1.1
3415 * This chunk MUST be sent in an authenticated way by using
3416 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3417 * is received unauthenticated it MUST be silently discarded as
3418 * described in [I-D.ietf-tsvwg-sctp-auth].
3420 if (!sctp_addip_noauth && !chunk->auth)
3421 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3423 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3424 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3425 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3428 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3429 serial = ntohl(hdr->serial);
3431 addr_param = (union sctp_addr_param *)hdr->params;
3432 length = ntohs(addr_param->p.length);
3433 if (length < sizeof(sctp_paramhdr_t))
3434 return sctp_sf_violation_paramlen(ep, asoc, type,
3435 (void *)addr_param, commands);
3437 /* Verify the ASCONF chunk before processing it. */
3438 if (!sctp_verify_asconf(asoc,
3439 (sctp_paramhdr_t *)((void *)addr_param + length),
3440 (void *)chunk->chunk_end,
3442 return sctp_sf_violation_paramlen(ep, asoc, type,
3443 (void *)&err_param, commands);
3445 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3446 * the endpoint stored in a new association variable
3447 * 'Peer-Serial-Number'.
3449 if (serial == asoc->peer.addip_serial + 1) {
3450 /* If this is the first instance of ASCONF in the packet,
3451 * we can clean our old ASCONF-ACKs.
3453 if (!chunk->has_asconf)
3454 sctp_assoc_clean_asconf_ack_cache(asoc);
3456 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3457 * expected, process the ASCONF as described below and after
3458 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3459 * the response packet and cache a copy of it (in the event it
3460 * later needs to be retransmitted).
3462 * Essentially, do V1-V5.
3464 asconf_ack = sctp_process_asconf((struct sctp_association *)
3467 return SCTP_DISPOSITION_NOMEM;
3468 } else if (serial < asoc->peer.addip_serial + 1) {
3470 * If the value found in the Sequence Number is less than the
3471 * ('Peer- Sequence-Number' + 1), simply skip to the next
3472 * ASCONF, and include in the outbound response packet
3473 * any previously cached ASCONF-ACK response that was
3474 * sent and saved that matches the Sequence Number of the
3475 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3476 * Chunk exists. This will occur when an older ASCONF
3477 * arrives out of order. In such a case, the receiver
3478 * should skip the ASCONF Chunk and not include ASCONF-ACK
3479 * Chunk for that chunk.
3481 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3483 return SCTP_DISPOSITION_DISCARD;
3485 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3486 * it must be either a stale packet or from an attacker.
3488 return SCTP_DISPOSITION_DISCARD;
3491 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3492 * containing the ASCONF-ACK Chunks MUST be the source address of
3493 * the SCTP packet that held the ASCONF Chunks.
3495 * To do this properly, we'll set the destination address of the chunk
3496 * and at the transmit time, will try look up the transport to use.
3497 * Since ASCONFs may be bundled, the correct transport may not be
3498 * created untill we process the entire packet, thus this workaround.
3500 asconf_ack->dest = chunk->source;
3501 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3503 return SCTP_DISPOSITION_CONSUME;
3507 * ADDIP Section 4.3 General rules for address manipulation
3508 * When building TLV parameters for the ASCONF Chunk that will add or
3509 * delete IP addresses the D0 to D13 rules should be applied:
3511 sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3512 const struct sctp_association *asoc,
3513 const sctp_subtype_t type, void *arg,
3514 sctp_cmd_seq_t *commands)
3516 struct sctp_chunk *asconf_ack = arg;
3517 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3518 struct sctp_chunk *abort;
3519 struct sctp_paramhdr *err_param = NULL;
3520 sctp_addiphdr_t *addip_hdr;
3521 __u32 sent_serial, rcvd_serial;
3523 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3524 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3526 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3529 /* ADD-IP, Section 4.1.2:
3530 * This chunk MUST be sent in an authenticated way by using
3531 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3532 * is received unauthenticated it MUST be silently discarded as
3533 * described in [I-D.ietf-tsvwg-sctp-auth].
3535 if (!sctp_addip_noauth && !asconf_ack->auth)
3536 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3538 /* Make sure that the ADDIP chunk has a valid length. */
3539 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3540 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3543 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3544 rcvd_serial = ntohl(addip_hdr->serial);
3546 /* Verify the ASCONF-ACK chunk before processing it. */
3547 if (!sctp_verify_asconf(asoc,
3548 (sctp_paramhdr_t *)addip_hdr->params,
3549 (void *)asconf_ack->chunk_end,
3551 return sctp_sf_violation_paramlen(ep, asoc, type,
3552 (void *)&err_param, commands);
3555 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3556 sent_serial = ntohl(addip_hdr->serial);
3558 sent_serial = asoc->addip_serial - 1;
3561 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3562 * equal to the next serial number to be used but no ASCONF chunk is
3563 * outstanding the endpoint MUST ABORT the association. Note that a
3564 * sequence number is greater than if it is no more than 2^^31-1
3565 * larger than the current sequence number (using serial arithmetic).
3567 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3568 !(asoc->addip_last_asconf)) {
3569 abort = sctp_make_abort(asoc, asconf_ack,
3570 sizeof(sctp_errhdr_t));
3572 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3573 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3576 /* We are going to ABORT, so we might as well stop
3577 * processing the rest of the chunks in the packet.
3579 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3580 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3581 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3582 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3583 SCTP_ERROR(ECONNABORTED));
3584 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3585 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3586 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3587 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3588 return SCTP_DISPOSITION_ABORT;
3591 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3592 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3593 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3595 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3597 return SCTP_DISPOSITION_CONSUME;
3599 abort = sctp_make_abort(asoc, asconf_ack,
3600 sizeof(sctp_errhdr_t));
3602 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3603 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3606 /* We are going to ABORT, so we might as well stop
3607 * processing the rest of the chunks in the packet.
3609 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3610 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3611 SCTP_ERROR(ECONNABORTED));
3612 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3613 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3614 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3615 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3616 return SCTP_DISPOSITION_ABORT;
3619 return SCTP_DISPOSITION_DISCARD;
3623 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3625 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3626 * its cumulative TSN point to the value carried in the FORWARD TSN
3627 * chunk, and then MUST further advance its cumulative TSN point locally
3629 * After the above processing, the data receiver MUST stop reporting any
3630 * missing TSNs earlier than or equal to the new cumulative TSN point.
3632 * Verification Tag: 8.5 Verification Tag [Normal verification]
3634 * The return value is the disposition of the chunk.
3636 sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3637 const struct sctp_association *asoc,
3638 const sctp_subtype_t type,
3640 sctp_cmd_seq_t *commands)
3642 struct sctp_chunk *chunk = arg;
3643 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3647 if (!sctp_vtag_verify(chunk, asoc)) {
3648 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3650 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3653 /* Make sure that the FORWARD_TSN chunk has valid length. */
3654 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3655 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3658 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3659 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3660 len = ntohs(chunk->chunk_hdr->length);
3661 len -= sizeof(struct sctp_chunkhdr);
3662 skb_pull(chunk->skb, len);
3664 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3665 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3667 /* The TSN is too high--silently discard the chunk and count on it
3668 * getting retransmitted later.
3670 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3671 goto discard_noforce;
3673 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3674 if (len > sizeof(struct sctp_fwdtsn_hdr))
3675 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3678 /* Count this as receiving DATA. */
3679 if (asoc->autoclose) {
3680 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3681 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3684 /* FIXME: For now send a SACK, but DATA processing may
3687 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3689 return SCTP_DISPOSITION_CONSUME;
3692 return SCTP_DISPOSITION_DISCARD;
3695 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3696 const struct sctp_endpoint *ep,
3697 const struct sctp_association *asoc,
3698 const sctp_subtype_t type,
3700 sctp_cmd_seq_t *commands)
3702 struct sctp_chunk *chunk = arg;
3703 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3707 if (!sctp_vtag_verify(chunk, asoc)) {
3708 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3710 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3713 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3714 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3715 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3718 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3719 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3720 len = ntohs(chunk->chunk_hdr->length);
3721 len -= sizeof(struct sctp_chunkhdr);
3722 skb_pull(chunk->skb, len);
3724 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3725 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3727 /* The TSN is too high--silently discard the chunk and count on it
3728 * getting retransmitted later.
3730 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3733 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3734 if (len > sizeof(struct sctp_fwdtsn_hdr))
3735 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3738 /* Go a head and force a SACK, since we are shutting down. */
3740 /* Implementor's Guide.
3742 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3743 * respond to each received packet containing one or more DATA chunk(s)
3744 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3746 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3747 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3748 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3749 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3751 return SCTP_DISPOSITION_CONSUME;
3755 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3757 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3758 * Identifier field. If this algorithm was not specified by the
3759 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3760 * during association setup, the AUTH chunk and all chunks after it MUST
3761 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3762 * defined in Section 4.1.
3764 * If an endpoint with no shared key receives a Shared Key Identifier
3765 * other than 0, it MUST silently discard all authenticated chunks. If
3766 * the endpoint has at least one endpoint pair shared key for the peer,
3767 * it MUST use the key specified by the Shared Key Identifier if a
3768 * key has been configured for that Shared Key Identifier. If no
3769 * endpoint pair shared key has been configured for that Shared Key
3770 * Identifier, all authenticated chunks MUST be silently discarded.
3772 * Verification Tag: 8.5 Verification Tag [Normal verification]
3774 * The return value is the disposition of the chunk.
3776 static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3777 const struct sctp_association *asoc,
3778 const sctp_subtype_t type,
3779 struct sctp_chunk *chunk)
3781 struct sctp_authhdr *auth_hdr;
3782 struct sctp_hmac *hmac;
3783 unsigned int sig_len;
3788 /* Pull in the auth header, so we can do some more verification */
3789 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3790 chunk->subh.auth_hdr = auth_hdr;
3791 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3793 /* Make sure that we suport the HMAC algorithm from the auth
3796 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3797 return SCTP_IERROR_AUTH_BAD_HMAC;
3799 /* Make sure that the provided shared key identifier has been
3802 key_id = ntohs(auth_hdr->shkey_id);
3803 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3804 return SCTP_IERROR_AUTH_BAD_KEYID;
3807 /* Make sure that the length of the signature matches what
3810 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3811 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3812 if (sig_len != hmac->hmac_len)
3813 return SCTP_IERROR_PROTO_VIOLATION;
3815 /* Now that we've done validation checks, we can compute and
3816 * verify the hmac. The steps involved are:
3817 * 1. Save the digest from the chunk.
3818 * 2. Zero out the digest in the chunk.
3819 * 3. Compute the new digest
3820 * 4. Compare saved and new digests.
3822 digest = auth_hdr->hmac;
3823 skb_pull(chunk->skb, sig_len);
3825 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3829 memset(digest, 0, sig_len);
3831 sctp_auth_calculate_hmac(asoc, chunk->skb,
3832 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3835 /* Discard the packet if the digests do not match */
3836 if (memcmp(save_digest, digest, sig_len)) {
3838 return SCTP_IERROR_BAD_SIG;
3844 return SCTP_IERROR_NO_ERROR;
3846 return SCTP_IERROR_NOMEM;
3849 sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3850 const struct sctp_association *asoc,
3851 const sctp_subtype_t type,
3853 sctp_cmd_seq_t *commands)
3855 struct sctp_authhdr *auth_hdr;
3856 struct sctp_chunk *chunk = arg;
3857 struct sctp_chunk *err_chunk;
3858 sctp_ierror_t error;
3860 /* Make sure that the peer has AUTH capable */
3861 if (!asoc->peer.auth_capable)
3862 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
3864 if (!sctp_vtag_verify(chunk, asoc)) {
3865 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3867 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3870 /* Make sure that the AUTH chunk has valid length. */
3871 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
3872 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3875 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3876 error = sctp_sf_authenticate(ep, asoc, type, chunk);
3878 case SCTP_IERROR_AUTH_BAD_HMAC:
3879 /* Generate the ERROR chunk and discard the rest
3882 err_chunk = sctp_make_op_error(asoc, chunk,
3883 SCTP_ERROR_UNSUP_HMAC,
3887 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3888 SCTP_CHUNK(err_chunk));
3891 case SCTP_IERROR_AUTH_BAD_KEYID:
3892 case SCTP_IERROR_BAD_SIG:
3893 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3895 case SCTP_IERROR_PROTO_VIOLATION:
3896 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3899 case SCTP_IERROR_NOMEM:
3900 return SCTP_DISPOSITION_NOMEM;
3905 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
3906 struct sctp_ulpevent *ev;
3908 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
3909 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
3914 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3918 return SCTP_DISPOSITION_CONSUME;
3922 * Process an unknown chunk.
3924 * Section: 3.2. Also, 2.1 in the implementor's guide.
3926 * Chunk Types are encoded such that the highest-order two bits specify
3927 * the action that must be taken if the processing endpoint does not
3928 * recognize the Chunk Type.
3930 * 00 - Stop processing this SCTP packet and discard it, do not process
3931 * any further chunks within it.
3933 * 01 - Stop processing this SCTP packet and discard it, do not process
3934 * any further chunks within it, and report the unrecognized
3935 * chunk in an 'Unrecognized Chunk Type'.
3937 * 10 - Skip this chunk and continue processing.
3939 * 11 - Skip this chunk and continue processing, but report in an ERROR
3940 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3942 * The return value is the disposition of the chunk.
3944 sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3945 const struct sctp_association *asoc,
3946 const sctp_subtype_t type,
3948 sctp_cmd_seq_t *commands)
3950 struct sctp_chunk *unk_chunk = arg;
3951 struct sctp_chunk *err_chunk;
3952 sctp_chunkhdr_t *hdr;
3954 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3956 if (!sctp_vtag_verify(unk_chunk, asoc))
3957 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3959 /* Make sure that the chunk has a valid length.
3960 * Since we don't know the chunk type, we use a general
3961 * chunkhdr structure to make a comparison.
3963 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3964 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3967 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3968 case SCTP_CID_ACTION_DISCARD:
3969 /* Discard the packet. */
3970 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3972 case SCTP_CID_ACTION_DISCARD_ERR:
3973 /* Discard the packet. */
3974 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3976 /* Generate an ERROR chunk as response. */
3977 hdr = unk_chunk->chunk_hdr;
3978 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3979 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3980 WORD_ROUND(ntohs(hdr->length)));
3982 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3983 SCTP_CHUNK(err_chunk));
3985 return SCTP_DISPOSITION_CONSUME;
3987 case SCTP_CID_ACTION_SKIP:
3988 /* Skip the chunk. */
3989 return SCTP_DISPOSITION_DISCARD;
3991 case SCTP_CID_ACTION_SKIP_ERR:
3992 /* Generate an ERROR chunk as response. */
3993 hdr = unk_chunk->chunk_hdr;
3994 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3995 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3996 WORD_ROUND(ntohs(hdr->length)));
3998 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3999 SCTP_CHUNK(err_chunk));
4001 /* Skip the chunk. */
4002 return SCTP_DISPOSITION_CONSUME;
4008 return SCTP_DISPOSITION_DISCARD;
4012 * Discard the chunk.
4014 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4015 * [Too numerous to mention...]
4016 * Verification Tag: No verification needed.
4018 * (endpoint, asoc, chunk)
4021 * (asoc, reply_msg, msg_up, timers, counters)
4023 * The return value is the disposition of the chunk.
4025 sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4026 const struct sctp_association *asoc,
4027 const sctp_subtype_t type,
4029 sctp_cmd_seq_t *commands)
4031 struct sctp_chunk *chunk = arg;
4033 /* Make sure that the chunk has a valid length.
4034 * Since we don't know the chunk type, we use a general
4035 * chunkhdr structure to make a comparison.
4037 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4038 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4041 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4042 return SCTP_DISPOSITION_DISCARD;
4046 * Discard the whole packet.
4050 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4051 * silently discard the OOTB packet and take no further action.
4053 * Verification Tag: No verification necessary
4056 * (endpoint, asoc, chunk)
4059 * (asoc, reply_msg, msg_up, timers, counters)
4061 * The return value is the disposition of the chunk.
4063 sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4064 const struct sctp_association *asoc,
4065 const sctp_subtype_t type,
4067 sctp_cmd_seq_t *commands)
4069 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
4070 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4072 return SCTP_DISPOSITION_CONSUME;
4077 * The other end is violating protocol.
4079 * Section: Not specified
4080 * Verification Tag: Not specified
4082 * (endpoint, asoc, chunk)
4085 * (asoc, reply_msg, msg_up, timers, counters)
4087 * We simply tag the chunk as a violation. The state machine will log
4088 * the violation and continue.
4090 sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4091 const struct sctp_association *asoc,
4092 const sctp_subtype_t type,
4094 sctp_cmd_seq_t *commands)
4096 struct sctp_chunk *chunk = arg;
4098 /* Make sure that the chunk has a valid length. */
4099 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4100 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4103 return SCTP_DISPOSITION_VIOLATION;
4107 * Common function to handle a protocol violation.
4109 static sctp_disposition_t sctp_sf_abort_violation(
4110 const struct sctp_endpoint *ep,
4111 const struct sctp_association *asoc,
4113 sctp_cmd_seq_t *commands,
4114 const __u8 *payload,
4115 const size_t paylen)
4117 struct sctp_packet *packet = NULL;
4118 struct sctp_chunk *chunk = arg;
4119 struct sctp_chunk *abort = NULL;
4121 /* SCTP-AUTH, Section 6.3:
4122 * It should be noted that if the receiver wants to tear
4123 * down an association in an authenticated way only, the
4124 * handling of malformed packets should not result in
4125 * tearing down the association.
4127 * This means that if we only want to abort associations
4128 * in an authenticated way (i.e AUTH+ABORT), then we
4129 * can't destroy this association just becuase the packet
4132 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4135 /* Make the abort chunk. */
4136 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4141 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4142 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4144 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4145 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4146 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4147 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4148 SCTP_ERROR(ECONNREFUSED));
4149 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4150 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4152 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4153 SCTP_ERROR(ECONNABORTED));
4154 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4155 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4156 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4159 packet = sctp_ootb_pkt_new(asoc, chunk);
4164 if (sctp_test_T_bit(abort))
4165 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4167 abort->skb->sk = ep->base.sk;
4169 sctp_packet_append_chunk(packet, abort);
4171 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4172 SCTP_PACKET(packet));
4174 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4178 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4180 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4182 return SCTP_DISPOSITION_ABORT;
4185 sctp_chunk_free(abort);
4187 return SCTP_DISPOSITION_NOMEM;
4191 * Handle a protocol violation when the chunk length is invalid.
4192 * "Invalid" length is identified as smaller then the minimal length a
4193 * given chunk can be. For example, a SACK chunk has invalid length
4194 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
4196 * We inform the other end by sending an ABORT with a Protocol Violation
4199 * Section: Not specified
4200 * Verification Tag: Nothing to do
4202 * (endpoint, asoc, chunk)
4205 * (reply_msg, msg_up, counters)
4207 * Generate an ABORT chunk and terminate the association.
4209 static sctp_disposition_t sctp_sf_violation_chunklen(
4210 const struct sctp_endpoint *ep,
4211 const struct sctp_association *asoc,
4212 const sctp_subtype_t type,
4214 sctp_cmd_seq_t *commands)
4216 static const char err_str[]="The following chunk had invalid length:";
4218 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4223 * Handle a protocol violation when the parameter length is invalid.
4224 * "Invalid" length is identified as smaller then the minimal length a
4225 * given parameter can be.
4227 static sctp_disposition_t sctp_sf_violation_paramlen(
4228 const struct sctp_endpoint *ep,
4229 const struct sctp_association *asoc,
4230 const sctp_subtype_t type,
4232 sctp_cmd_seq_t *commands) {
4233 static const char err_str[] = "The following parameter had invalid length:";
4235 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4239 /* Handle a protocol violation when the peer trying to advance the
4240 * cumulative tsn ack to a point beyond the max tsn currently sent.
4242 * We inform the other end by sending an ABORT with a Protocol Violation
4245 static sctp_disposition_t sctp_sf_violation_ctsn(
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 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
4254 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4258 /* Handle protocol violation of an invalid chunk bundling. For example,
4259 * when we have an association and we recieve bundled INIT-ACK, or
4260 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4261 * statement from the specs. Additinally, there might be an attacker
4262 * on the path and we may not want to continue this communication.
4264 static sctp_disposition_t sctp_sf_violation_chunk(
4265 const struct sctp_endpoint *ep,
4266 const struct sctp_association *asoc,
4267 const sctp_subtype_t type,
4269 sctp_cmd_seq_t *commands)
4271 static const char err_str[]="The following chunk violates protocol:";
4274 return sctp_sf_violation(ep, asoc, type, arg, commands);
4276 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4279 /***************************************************************************
4280 * These are the state functions for handling primitive (Section 10) events.
4281 ***************************************************************************/
4283 * sctp_sf_do_prm_asoc
4285 * Section: 10.1 ULP-to-SCTP
4288 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4289 * outbound stream count)
4290 * -> association id [,destination transport addr list] [,outbound stream
4293 * This primitive allows the upper layer to initiate an association to a
4294 * specific peer endpoint.
4296 * The peer endpoint shall be specified by one of the transport addresses
4297 * which defines the endpoint (see Section 1.4). If the local SCTP
4298 * instance has not been initialized, the ASSOCIATE is considered an
4300 * [This is not relevant for the kernel implementation since we do all
4301 * initialization at boot time. It we hadn't initialized we wouldn't
4302 * get anywhere near this code.]
4304 * An association id, which is a local handle to the SCTP association,
4305 * will be returned on successful establishment of the association. If
4306 * SCTP is not able to open an SCTP association with the peer endpoint,
4307 * an error is returned.
4308 * [In the kernel implementation, the struct sctp_association needs to
4309 * be created BEFORE causing this primitive to run.]
4311 * Other association parameters may be returned, including the
4312 * complete destination transport addresses of the peer as well as the
4313 * outbound stream count of the local endpoint. One of the transport
4314 * address from the returned destination addresses will be selected by
4315 * the local endpoint as default primary path for sending SCTP packets
4316 * to this peer. The returned "destination transport addr list" can
4317 * be used by the ULP to change the default primary path or to force
4318 * sending a packet to a specific transport address. [All of this
4319 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4322 * Mandatory attributes:
4324 * o local SCTP instance name - obtained from the INITIALIZE operation.
4325 * [This is the argument asoc.]
4326 * o destination transport addr - specified as one of the transport
4327 * addresses of the peer endpoint with which the association is to be
4329 * [This is asoc->peer.active_path.]
4330 * o outbound stream count - the number of outbound streams the ULP
4331 * would like to open towards this peer endpoint.
4332 * [BUG: This is not currently implemented.]
4333 * Optional attributes:
4337 * The return value is a disposition.
4339 sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4340 const struct sctp_association *asoc,
4341 const sctp_subtype_t type,
4343 sctp_cmd_seq_t *commands)
4345 struct sctp_chunk *repl;
4347 /* The comment below says that we enter COOKIE-WAIT AFTER
4348 * sending the INIT, but that doesn't actually work in our
4351 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4352 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4354 /* RFC 2960 5.1 Normal Establishment of an Association
4356 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4357 * must provide its Verification Tag (Tag_A) in the Initiate
4358 * Tag field. Tag_A SHOULD be a random number in the range of
4359 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4362 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4366 /* Cast away the const modifier, as we want to just
4367 * rerun it through as a sideffect.
4369 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
4370 SCTP_ASOC((struct sctp_association *) asoc));
4372 /* Choose transport for INIT. */
4373 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4376 /* After sending the INIT, "A" starts the T1-init timer and
4377 * enters the COOKIE-WAIT state.
4379 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4380 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4381 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4382 return SCTP_DISPOSITION_CONSUME;
4385 return SCTP_DISPOSITION_NOMEM;
4389 * Process the SEND primitive.
4391 * Section: 10.1 ULP-to-SCTP
4394 * Format: SEND(association id, buffer address, byte count [,context]
4395 * [,stream id] [,life time] [,destination transport address]
4396 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4399 * This is the main method to send user data via SCTP.
4401 * Mandatory attributes:
4403 * o association id - local handle to the SCTP association
4405 * o buffer address - the location where the user message to be
4406 * transmitted is stored;
4408 * o byte count - The size of the user data in number of bytes;
4410 * Optional attributes:
4412 * o context - an optional 32 bit integer that will be carried in the
4413 * sending failure notification to the ULP if the transportation of
4414 * this User Message fails.
4416 * o stream id - to indicate which stream to send the data on. If not
4417 * specified, stream 0 will be used.
4419 * o life time - specifies the life time of the user data. The user data
4420 * will not be sent by SCTP after the life time expires. This
4421 * parameter can be used to avoid efforts to transmit stale
4422 * user messages. SCTP notifies the ULP if the data cannot be
4423 * initiated to transport (i.e. sent to the destination via SCTP's
4424 * send primitive) within the life time variable. However, the
4425 * user data will be transmitted if SCTP has attempted to transmit a
4426 * chunk before the life time expired.
4428 * o destination transport address - specified as one of the destination
4429 * transport addresses of the peer endpoint to which this packet
4430 * should be sent. Whenever possible, SCTP should use this destination
4431 * transport address for sending the packets, instead of the current
4434 * o unorder flag - this flag, if present, indicates that the user
4435 * would like the data delivered in an unordered fashion to the peer
4436 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4439 * o no-bundle flag - instructs SCTP not to bundle this user data with
4440 * other outbound DATA chunks. SCTP MAY still bundle even when
4441 * this flag is present, when faced with network congestion.
4443 * o payload protocol-id - A 32 bit unsigned integer that is to be
4444 * passed to the peer indicating the type of payload protocol data
4445 * being transmitted. This value is passed as opaque data by SCTP.
4447 * The return value is the disposition.
4449 sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4450 const struct sctp_association *asoc,
4451 const sctp_subtype_t type,
4453 sctp_cmd_seq_t *commands)
4455 struct sctp_chunk *chunk = arg;
4457 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4458 return SCTP_DISPOSITION_CONSUME;
4462 * Process the SHUTDOWN primitive.
4467 * Format: SHUTDOWN(association id)
4470 * Gracefully closes an association. Any locally queued user data
4471 * will be delivered to the peer. The association will be terminated only
4472 * after the peer acknowledges all the SCTP packets sent. A success code
4473 * will be returned on successful termination of the association. If
4474 * attempting to terminate the association results in a failure, an error
4475 * code shall be returned.
4477 * Mandatory attributes:
4479 * o association id - local handle to the SCTP association
4481 * Optional attributes:
4485 * The return value is the disposition.
4487 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4488 const struct sctp_endpoint *ep,
4489 const struct sctp_association *asoc,
4490 const sctp_subtype_t type,
4492 sctp_cmd_seq_t *commands)
4496 /* From 9.2 Shutdown of an Association
4497 * Upon receipt of the SHUTDOWN primitive from its upper
4498 * layer, the endpoint enters SHUTDOWN-PENDING state and
4499 * remains there until all outstanding data has been
4500 * acknowledged by its peer. The endpoint accepts no new data
4501 * from its upper layer, but retransmits data to the far end
4502 * if necessary to fill gaps.
4504 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4505 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4507 /* sctpimpguide-05 Section 2.12.2
4508 * The sender of the SHUTDOWN MAY also start an overall guard timer
4509 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4511 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4512 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4514 disposition = SCTP_DISPOSITION_CONSUME;
4515 if (sctp_outq_is_empty(&asoc->outqueue)) {
4516 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4523 * Process the ABORT primitive.
4528 * Format: Abort(association id [, cause code])
4531 * Ungracefully closes an association. Any locally queued user data
4532 * will be discarded and an ABORT chunk is sent to the peer. A success code
4533 * will be returned on successful abortion of the association. If
4534 * attempting to abort the association results in a failure, an error
4535 * code shall be returned.
4537 * Mandatory attributes:
4539 * o association id - local handle to the SCTP association
4541 * Optional attributes:
4543 * o cause code - reason of the abort to be passed to the peer
4547 * The return value is the disposition.
4549 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4550 const struct sctp_endpoint *ep,
4551 const struct sctp_association *asoc,
4552 const sctp_subtype_t type,
4554 sctp_cmd_seq_t *commands)
4556 /* From 9.1 Abort of an Association
4557 * Upon receipt of the ABORT primitive from its upper
4558 * layer, the endpoint enters CLOSED state and
4559 * discard all outstanding data has been
4560 * acknowledged by its peer. The endpoint accepts no new data
4561 * from its upper layer, but retransmits data to the far end
4562 * if necessary to fill gaps.
4564 struct sctp_chunk *abort = arg;
4565 sctp_disposition_t retval;
4567 retval = SCTP_DISPOSITION_CONSUME;
4569 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4571 /* Even if we can't send the ABORT due to low memory delete the
4572 * TCB. This is a departure from our typical NOMEM handling.
4575 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4576 SCTP_ERROR(ECONNABORTED));
4577 /* Delete the established association. */
4578 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4579 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4581 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4582 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4587 /* We tried an illegal operation on an association which is closed. */
4588 sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4589 const struct sctp_association *asoc,
4590 const sctp_subtype_t type,
4592 sctp_cmd_seq_t *commands)
4594 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4595 return SCTP_DISPOSITION_CONSUME;
4598 /* We tried an illegal operation on an association which is shutting
4601 sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4602 const struct sctp_association *asoc,
4603 const sctp_subtype_t type,
4605 sctp_cmd_seq_t *commands)
4607 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4608 SCTP_ERROR(-ESHUTDOWN));
4609 return SCTP_DISPOSITION_CONSUME;
4613 * sctp_cookie_wait_prm_shutdown
4615 * Section: 4 Note: 2
4620 * The RFC does not explicitly address this issue, but is the route through the
4621 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4626 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4627 const struct sctp_endpoint *ep,
4628 const struct sctp_association *asoc,
4629 const sctp_subtype_t type,
4631 sctp_cmd_seq_t *commands)
4633 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4634 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4636 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4637 SCTP_STATE(SCTP_STATE_CLOSED));
4639 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4641 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4643 return SCTP_DISPOSITION_DELETE_TCB;
4647 * sctp_cookie_echoed_prm_shutdown
4649 * Section: 4 Note: 2
4654 * The RFC does not explcitly address this issue, but is the route through the
4655 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4660 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4661 const struct sctp_endpoint *ep,
4662 const struct sctp_association *asoc,
4663 const sctp_subtype_t type,
4664 void *arg, sctp_cmd_seq_t *commands)
4666 /* There is a single T1 timer, so we should be able to use
4667 * common function with the COOKIE-WAIT state.
4669 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4673 * sctp_sf_cookie_wait_prm_abort
4675 * Section: 4 Note: 2
4680 * The RFC does not explicitly address this issue, but is the route through the
4681 * state table when someone issues an abort while in COOKIE_WAIT state.
4686 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4687 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 *abort = arg;
4694 sctp_disposition_t retval;
4696 /* Stop T1-init timer */
4697 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4698 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4699 retval = SCTP_DISPOSITION_CONSUME;
4701 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4703 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4704 SCTP_STATE(SCTP_STATE_CLOSED));
4706 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4708 /* Even if we can't send the ABORT due to low memory delete the
4709 * TCB. This is a departure from our typical NOMEM handling.
4712 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4713 SCTP_ERROR(ECONNREFUSED));
4714 /* Delete the established association. */
4715 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4716 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4722 * sctp_sf_cookie_echoed_prm_abort
4724 * Section: 4 Note: 3
4729 * The RFC does not explcitly address this issue, but is the route through the
4730 * state table when someone issues an abort while in COOKIE_ECHOED state.
4735 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4736 const struct sctp_endpoint *ep,
4737 const struct sctp_association *asoc,
4738 const sctp_subtype_t type,
4740 sctp_cmd_seq_t *commands)
4742 /* There is a single T1 timer, so we should be able to use
4743 * common function with the COOKIE-WAIT state.
4745 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4749 * sctp_sf_shutdown_pending_prm_abort
4754 * The RFC does not explicitly address this issue, but is the route through the
4755 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4760 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4761 const struct sctp_endpoint *ep,
4762 const struct sctp_association *asoc,
4763 const sctp_subtype_t type,
4765 sctp_cmd_seq_t *commands)
4767 /* Stop the T5-shutdown guard timer. */
4768 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4769 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4771 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4775 * sctp_sf_shutdown_sent_prm_abort
4780 * The RFC does not explicitly address this issue, but is the route through the
4781 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4786 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4787 const struct sctp_endpoint *ep,
4788 const struct sctp_association *asoc,
4789 const sctp_subtype_t type,
4791 sctp_cmd_seq_t *commands)
4793 /* Stop the T2-shutdown timer. */
4794 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4795 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4797 /* Stop the T5-shutdown guard timer. */
4798 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4799 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4801 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4805 * sctp_sf_cookie_echoed_prm_abort
4810 * The RFC does not explcitly address this issue, but is the route through the
4811 * state table when someone issues an abort while in COOKIE_ECHOED state.
4816 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4817 const struct sctp_endpoint *ep,
4818 const struct sctp_association *asoc,
4819 const sctp_subtype_t type,
4821 sctp_cmd_seq_t *commands)
4823 /* The same T2 timer, so we should be able to use
4824 * common function with the SHUTDOWN-SENT state.
4826 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4830 * Process the REQUESTHEARTBEAT primitive
4833 * J) Request Heartbeat
4835 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4839 * Instructs the local endpoint to perform a HeartBeat on the specified
4840 * destination transport address of the given association. The returned
4841 * result should indicate whether the transmission of the HEARTBEAT
4842 * chunk to the destination address is successful.
4844 * Mandatory attributes:
4846 * o association id - local handle to the SCTP association
4848 * o destination transport address - the transport address of the
4849 * association on which a heartbeat should be issued.
4851 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4852 const struct sctp_endpoint *ep,
4853 const struct sctp_association *asoc,
4854 const sctp_subtype_t type,
4856 sctp_cmd_seq_t *commands)
4858 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4859 (struct sctp_transport *)arg, commands))
4860 return SCTP_DISPOSITION_NOMEM;
4863 * RFC 2960 (bis), section 8.3
4865 * D) Request an on-demand HEARTBEAT on a specific destination
4866 * transport address of a given association.
4868 * The endpoint should increment the respective error counter of
4869 * the destination transport address each time a HEARTBEAT is sent
4870 * to that address and not acknowledged within one RTO.
4873 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
4874 SCTP_TRANSPORT(arg));
4875 return SCTP_DISPOSITION_CONSUME;
4879 * ADDIP Section 4.1 ASCONF Chunk Procedures
4880 * When an endpoint has an ASCONF signaled change to be sent to the
4881 * remote endpoint it should do A1 to A9
4883 sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4884 const struct sctp_association *asoc,
4885 const sctp_subtype_t type,
4887 sctp_cmd_seq_t *commands)
4889 struct sctp_chunk *chunk = arg;
4891 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4892 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4893 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4894 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4895 return SCTP_DISPOSITION_CONSUME;
4899 * Ignore the primitive event
4901 * The return value is the disposition of the primitive.
4903 sctp_disposition_t sctp_sf_ignore_primitive(
4904 const struct sctp_endpoint *ep,
4905 const struct sctp_association *asoc,
4906 const sctp_subtype_t type,
4908 sctp_cmd_seq_t *commands)
4910 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4911 return SCTP_DISPOSITION_DISCARD;
4914 /***************************************************************************
4915 * These are the state functions for the OTHER events.
4916 ***************************************************************************/
4919 * Start the shutdown negotiation.
4922 * Once all its outstanding data has been acknowledged, the endpoint
4923 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4924 * TSN Ack field the last sequential TSN it has received from the peer.
4925 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4926 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4927 * with the updated last sequential TSN received from its peer.
4929 * The return value is the disposition.
4931 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4932 const struct sctp_endpoint *ep,
4933 const struct sctp_association *asoc,
4934 const sctp_subtype_t type,
4936 sctp_cmd_seq_t *commands)
4938 struct sctp_chunk *reply;
4940 /* Once all its outstanding data has been acknowledged, the
4941 * endpoint shall send a SHUTDOWN chunk to its peer including
4942 * in the Cumulative TSN Ack field the last sequential TSN it
4943 * has received from the peer.
4945 reply = sctp_make_shutdown(asoc, NULL);
4949 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4950 * T2-shutdown timer.
4952 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4954 /* It shall then start the T2-shutdown timer */
4955 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4956 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4958 if (asoc->autoclose)
4959 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4960 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4962 /* and enter the SHUTDOWN-SENT state. */
4963 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4964 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4966 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4968 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4971 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4973 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4975 return SCTP_DISPOSITION_CONSUME;
4978 return SCTP_DISPOSITION_NOMEM;
4982 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4986 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4987 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4988 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4989 * endpoint must re-send the SHUTDOWN ACK.
4991 * The return value is the disposition.
4993 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4994 const struct sctp_endpoint *ep,
4995 const struct sctp_association *asoc,
4996 const sctp_subtype_t type,
4998 sctp_cmd_seq_t *commands)
5000 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5001 struct sctp_chunk *reply;
5003 /* There are 2 ways of getting here:
5004 * 1) called in response to a SHUTDOWN chunk
5005 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5007 * For the case (2), the arg parameter is set to NULL. We need
5008 * to check that we have a chunk before accessing it's fields.
5011 if (!sctp_vtag_verify(chunk, asoc))
5012 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5014 /* Make sure that the SHUTDOWN chunk has a valid length. */
5015 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5016 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5020 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5021 * shall send a SHUTDOWN ACK ...
5023 reply = sctp_make_shutdown_ack(asoc, chunk);
5027 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5028 * the T2-shutdown timer.
5030 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5032 /* and start/restart a T2-shutdown timer of its own, */
5033 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5034 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5036 if (asoc->autoclose)
5037 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5038 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5040 /* Enter the SHUTDOWN-ACK-SENT state. */
5041 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5042 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5044 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5046 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5049 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5051 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5053 return SCTP_DISPOSITION_CONSUME;
5056 return SCTP_DISPOSITION_NOMEM;
5060 * Ignore the event defined as other
5062 * The return value is the disposition of the event.
5064 sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5065 const struct sctp_association *asoc,
5066 const sctp_subtype_t type,
5068 sctp_cmd_seq_t *commands)
5070 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5071 return SCTP_DISPOSITION_DISCARD;
5074 /************************************************************
5075 * These are the state functions for handling timeout events.
5076 ************************************************************/
5081 * Section: 6.3.3 Handle T3-rtx Expiration
5083 * Whenever the retransmission timer T3-rtx expires for a destination
5084 * address, do the following:
5087 * The return value is the disposition of the chunk.
5089 sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5090 const struct sctp_association *asoc,
5091 const sctp_subtype_t type,
5093 sctp_cmd_seq_t *commands)
5095 struct sctp_transport *transport = arg;
5097 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5099 if (asoc->overall_error_count >= asoc->max_retrans) {
5100 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5101 SCTP_ERROR(ETIMEDOUT));
5102 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5103 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5104 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5105 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5106 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5107 return SCTP_DISPOSITION_DELETE_TCB;
5110 /* E1) For the destination address for which the timer
5111 * expires, adjust its ssthresh with rules defined in Section
5112 * 7.2.3 and set the cwnd <- MTU.
5115 /* E2) For the destination address for which the timer
5116 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5117 * maximum value discussed in rule C7 above (RTO.max) may be
5118 * used to provide an upper bound to this doubling operation.
5121 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5122 * outstanding DATA chunks for the address for which the
5123 * T3-rtx has expired will fit into a single packet, subject
5124 * to the MTU constraint for the path corresponding to the
5125 * destination transport address to which the retransmission
5126 * is being sent (this may be different from the address for
5127 * which the timer expires [see Section 6.4]). Call this
5128 * value K. Bundle and retransmit those K DATA chunks in a
5129 * single packet to the destination endpoint.
5131 * Note: Any DATA chunks that were sent to the address for
5132 * which the T3-rtx timer expired but did not fit in one MTU
5133 * (rule E3 above), should be marked for retransmission and
5134 * sent as soon as cwnd allows (normally when a SACK arrives).
5137 /* Do some failure management (Section 8.2). */
5138 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5140 /* NB: Rules E4 and F1 are implicit in R1. */
5141 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5143 return SCTP_DISPOSITION_CONSUME;
5147 * Generate delayed SACK on timeout
5149 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5151 * The guidelines on delayed acknowledgement algorithm specified in
5152 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5153 * acknowledgement SHOULD be generated for at least every second packet
5154 * (not every second DATA chunk) received, and SHOULD be generated
5155 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5156 * some situations it may be beneficial for an SCTP transmitter to be
5157 * more conservative than the algorithms detailed in this document
5158 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5159 * the following algorithms allow.
5161 sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5162 const struct sctp_association *asoc,
5163 const sctp_subtype_t type,
5165 sctp_cmd_seq_t *commands)
5167 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
5168 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5169 return SCTP_DISPOSITION_CONSUME;
5173 * sctp_sf_t1_init_timer_expire
5175 * Section: 4 Note: 2
5180 * RFC 2960 Section 4 Notes
5181 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5182 * and re-start the T1-init timer without changing state. This MUST
5183 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5184 * endpoint MUST abort the initialization process and report the
5185 * error to SCTP user.
5191 sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5192 const struct sctp_association *asoc,
5193 const sctp_subtype_t type,
5195 sctp_cmd_seq_t *commands)
5197 struct sctp_chunk *repl = NULL;
5198 struct sctp_bind_addr *bp;
5199 int attempts = asoc->init_err_counter + 1;
5201 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5202 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
5204 if (attempts <= asoc->max_init_attempts) {
5205 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5206 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5208 return SCTP_DISPOSITION_NOMEM;
5210 /* Choose transport for INIT. */
5211 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5214 /* Issue a sideeffect to do the needed accounting. */
5215 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5216 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5218 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5220 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5221 " max_init_attempts: %d\n",
5222 attempts, asoc->max_init_attempts);
5223 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5224 SCTP_ERROR(ETIMEDOUT));
5225 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5226 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5227 return SCTP_DISPOSITION_DELETE_TCB;
5230 return SCTP_DISPOSITION_CONSUME;
5234 * sctp_sf_t1_cookie_timer_expire
5236 * Section: 4 Note: 2
5241 * RFC 2960 Section 4 Notes
5242 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5243 * COOKIE ECHO and re-start the T1-cookie timer without changing
5244 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5245 * After that, the endpoint MUST abort the initialization process and
5246 * report the error to SCTP user.
5252 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
5253 const struct sctp_association *asoc,
5254 const sctp_subtype_t type,
5256 sctp_cmd_seq_t *commands)
5258 struct sctp_chunk *repl = NULL;
5259 int attempts = asoc->init_err_counter + 1;
5261 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5262 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
5264 if (attempts <= asoc->max_init_attempts) {
5265 repl = sctp_make_cookie_echo(asoc, NULL);
5267 return SCTP_DISPOSITION_NOMEM;
5269 /* Issue a sideeffect to do the needed accounting. */
5270 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5271 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5273 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5275 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5276 SCTP_ERROR(ETIMEDOUT));
5277 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5278 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5279 return SCTP_DISPOSITION_DELETE_TCB;
5282 return SCTP_DISPOSITION_CONSUME;
5285 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5286 * with the updated last sequential TSN received from its peer.
5288 * An endpoint should limit the number of retransmissions of the
5289 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5290 * If this threshold is exceeded the endpoint should destroy the TCB and
5291 * MUST report the peer endpoint unreachable to the upper layer (and
5292 * thus the association enters the CLOSED state). The reception of any
5293 * packet from its peer (i.e. as the peer sends all of its queued DATA
5294 * chunks) should clear the endpoint's retransmission count and restart
5295 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5296 * all of its queued DATA chunks that have not yet been sent.
5298 sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5299 const struct sctp_association *asoc,
5300 const sctp_subtype_t type,
5302 sctp_cmd_seq_t *commands)
5304 struct sctp_chunk *reply = NULL;
5306 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5307 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5309 ((struct sctp_association *)asoc)->shutdown_retries++;
5311 if (asoc->overall_error_count >= asoc->max_retrans) {
5312 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5313 SCTP_ERROR(ETIMEDOUT));
5314 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5315 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5316 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5317 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5318 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5319 return SCTP_DISPOSITION_DELETE_TCB;
5322 switch (asoc->state) {
5323 case SCTP_STATE_SHUTDOWN_SENT:
5324 reply = sctp_make_shutdown(asoc, NULL);
5327 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5328 reply = sctp_make_shutdown_ack(asoc, NULL);
5339 /* Do some failure management (Section 8.2). */
5340 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5341 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5343 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5344 * the T2-shutdown timer.
5346 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5348 /* Restart the T2-shutdown timer. */
5349 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5350 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5351 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5352 return SCTP_DISPOSITION_CONSUME;
5355 return SCTP_DISPOSITION_NOMEM;
5359 * ADDIP Section 4.1 ASCONF CHunk Procedures
5360 * If the T4 RTO timer expires the endpoint should do B1 to B5
5362 sctp_disposition_t sctp_sf_t4_timer_expire(
5363 const struct sctp_endpoint *ep,
5364 const struct sctp_association *asoc,
5365 const sctp_subtype_t type,
5367 sctp_cmd_seq_t *commands)
5369 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5370 struct sctp_transport *transport = chunk->transport;
5372 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5374 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5375 * detection on the appropriate destination address as defined in
5376 * RFC2960 [5] section 8.1 and 8.2.
5378 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5380 /* Reconfig T4 timer and transport. */
5381 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5383 /* ADDIP 4.1 B2) Increment the association error counters and perform
5384 * endpoint failure detection on the association as defined in
5385 * RFC2960 [5] section 8.1 and 8.2.
5386 * association error counter is incremented in SCTP_CMD_STRIKE.
5388 if (asoc->overall_error_count >= asoc->max_retrans) {
5389 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5390 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5391 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5392 SCTP_ERROR(ETIMEDOUT));
5393 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5394 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5395 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5396 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
5397 return SCTP_DISPOSITION_ABORT;
5400 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5401 * the ASCONF chunk was sent by doubling the RTO timer value.
5402 * This is done in SCTP_CMD_STRIKE.
5405 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5406 * choose an alternate destination address (please refer to RFC2960
5407 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5408 * chunk, it MUST be the same (including its serial number) as the last
5411 sctp_chunk_hold(asoc->addip_last_asconf);
5412 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5413 SCTP_CHUNK(asoc->addip_last_asconf));
5415 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5416 * destination is selected, then the RTO used will be that of the new
5417 * destination address.
5419 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5420 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5422 return SCTP_DISPOSITION_CONSUME;
5425 /* sctpimpguide-05 Section 2.12.2
5426 * The sender of the SHUTDOWN MAY also start an overall guard timer
5427 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5428 * At the expiration of this timer the sender SHOULD abort the association
5429 * by sending an ABORT chunk.
5431 sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5432 const struct sctp_association *asoc,
5433 const sctp_subtype_t type,
5435 sctp_cmd_seq_t *commands)
5437 struct sctp_chunk *reply = NULL;
5439 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5440 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5442 reply = sctp_make_abort(asoc, NULL, 0);
5446 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5447 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5448 SCTP_ERROR(ETIMEDOUT));
5449 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5450 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5452 return SCTP_DISPOSITION_DELETE_TCB;
5454 return SCTP_DISPOSITION_NOMEM;
5457 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5458 * the association is automatically closed by starting the shutdown process.
5459 * The work that needs to be done is same as when SHUTDOWN is initiated by
5460 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5462 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5463 const struct sctp_endpoint *ep,
5464 const struct sctp_association *asoc,
5465 const sctp_subtype_t type,
5467 sctp_cmd_seq_t *commands)
5471 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5473 /* From 9.2 Shutdown of an Association
5474 * Upon receipt of the SHUTDOWN primitive from its upper
5475 * layer, the endpoint enters SHUTDOWN-PENDING state and
5476 * remains there until all outstanding data has been
5477 * acknowledged by its peer. The endpoint accepts no new data
5478 * from its upper layer, but retransmits data to the far end
5479 * if necessary to fill gaps.
5481 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5482 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5484 /* sctpimpguide-05 Section 2.12.2
5485 * The sender of the SHUTDOWN MAY also start an overall guard timer
5486 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5488 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5489 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5490 disposition = SCTP_DISPOSITION_CONSUME;
5491 if (sctp_outq_is_empty(&asoc->outqueue)) {
5492 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5498 /*****************************************************************************
5499 * These are sa state functions which could apply to all types of events.
5500 ****************************************************************************/
5503 * This table entry is not implemented.
5506 * (endpoint, asoc, chunk)
5508 * The return value is the disposition of the chunk.
5510 sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5511 const struct sctp_association *asoc,
5512 const sctp_subtype_t type,
5514 sctp_cmd_seq_t *commands)
5516 return SCTP_DISPOSITION_NOT_IMPL;
5520 * This table entry represents a bug.
5523 * (endpoint, asoc, chunk)
5525 * The return value is the disposition of the chunk.
5527 sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5528 const struct sctp_association *asoc,
5529 const sctp_subtype_t type,
5531 sctp_cmd_seq_t *commands)
5533 return SCTP_DISPOSITION_BUG;
5537 * This table entry represents the firing of a timer in the wrong state.
5538 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5539 * when the association is in the wrong state. This event should
5540 * be ignored, so as to prevent any rearming of the timer.
5543 * (endpoint, asoc, chunk)
5545 * The return value is the disposition of the chunk.
5547 sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5548 const struct sctp_association *asoc,
5549 const sctp_subtype_t type,
5551 sctp_cmd_seq_t *commands)
5553 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5554 return SCTP_DISPOSITION_CONSUME;
5557 /********************************************************************
5558 * 2nd Level Abstractions
5559 ********************************************************************/
5561 /* Pull the SACK chunk based on the SACK header. */
5562 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5564 struct sctp_sackhdr *sack;
5569 /* Protect ourselves from reading too far into
5570 * the skb from a bogus sender.
5572 sack = (struct sctp_sackhdr *) chunk->skb->data;
5574 num_blocks = ntohs(sack->num_gap_ack_blocks);
5575 num_dup_tsns = ntohs(sack->num_dup_tsns);
5576 len = sizeof(struct sctp_sackhdr);
5577 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5578 if (len > chunk->skb->len)
5581 skb_pull(chunk->skb, len);
5586 /* Create an ABORT packet to be sent as a response, with the specified
5589 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5590 const struct sctp_association *asoc,
5591 struct sctp_chunk *chunk,
5592 const void *payload,
5595 struct sctp_packet *packet;
5596 struct sctp_chunk *abort;
5598 packet = sctp_ootb_pkt_new(asoc, chunk);
5602 * The T bit will be set if the asoc is NULL.
5604 abort = sctp_make_abort(asoc, chunk, paylen);
5606 sctp_ootb_pkt_free(packet);
5610 /* Reflect vtag if T-Bit is set */
5611 if (sctp_test_T_bit(abort))
5612 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5614 /* Add specified error causes, i.e., payload, to the
5617 sctp_addto_chunk(abort, paylen, payload);
5619 /* Set the skb to the belonging sock for accounting. */
5620 abort->skb->sk = ep->base.sk;
5622 sctp_packet_append_chunk(packet, abort);
5629 /* Allocate a packet for responding in the OOTB conditions. */
5630 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5631 const struct sctp_chunk *chunk)
5633 struct sctp_packet *packet;
5634 struct sctp_transport *transport;
5639 /* Get the source and destination port from the inbound packet. */
5640 sport = ntohs(chunk->sctp_hdr->dest);
5641 dport = ntohs(chunk->sctp_hdr->source);
5643 /* The V-tag is going to be the same as the inbound packet if no
5644 * association exists, otherwise, use the peer's vtag.
5647 /* Special case the INIT-ACK as there is no peer's vtag
5650 switch(chunk->chunk_hdr->type) {
5651 case SCTP_CID_INIT_ACK:
5653 sctp_initack_chunk_t *initack;
5655 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5656 vtag = ntohl(initack->init_hdr.init_tag);
5660 vtag = asoc->peer.i.init_tag;
5664 /* Special case the INIT and stale COOKIE_ECHO as there is no
5667 switch(chunk->chunk_hdr->type) {
5670 sctp_init_chunk_t *init;
5672 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5673 vtag = ntohl(init->init_hdr.init_tag);
5677 vtag = ntohl(chunk->sctp_hdr->vtag);
5682 /* Make a transport for the bucket, Eliza... */
5683 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5687 /* Cache a route for the transport with the chunk's destination as
5688 * the source address.
5690 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5691 sctp_sk(sctp_get_ctl_sock()));
5693 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5694 packet = sctp_packet_config(packet, vtag, 0);
5702 /* Free the packet allocated earlier for responding in the OOTB condition. */
5703 void sctp_ootb_pkt_free(struct sctp_packet *packet)
5705 sctp_transport_free(packet->transport);
5708 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5709 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5710 const struct sctp_association *asoc,
5711 const struct sctp_chunk *chunk,
5712 sctp_cmd_seq_t *commands,
5713 struct sctp_chunk *err_chunk)
5715 struct sctp_packet *packet;
5718 packet = sctp_ootb_pkt_new(asoc, chunk);
5720 struct sctp_signed_cookie *cookie;
5722 /* Override the OOTB vtag from the cookie. */
5723 cookie = chunk->subh.cookie_hdr;
5724 packet->vtag = cookie->c.peer_vtag;
5726 /* Set the skb to the belonging sock for accounting. */
5727 err_chunk->skb->sk = ep->base.sk;
5728 sctp_packet_append_chunk(packet, err_chunk);
5729 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5730 SCTP_PACKET(packet));
5731 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5733 sctp_chunk_free (err_chunk);
5738 /* Process a data chunk */
5739 static int sctp_eat_data(const struct sctp_association *asoc,
5740 struct sctp_chunk *chunk,
5741 sctp_cmd_seq_t *commands)
5743 sctp_datahdr_t *data_hdr;
5744 struct sctp_chunk *err;
5746 sctp_verb_t deliver;
5749 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
5750 struct sock *sk = asoc->base.sk;
5752 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5753 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5755 tsn = ntohl(data_hdr->tsn);
5756 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5758 /* ASSERT: Now skb->data is really the user data. */
5760 /* Process ECN based congestion.
5762 * Since the chunk structure is reused for all chunks within
5763 * a packet, we use ecn_ce_done to track if we've already
5764 * done CE processing for this packet.
5766 * We need to do ECN processing even if we plan to discard the
5770 if (!chunk->ecn_ce_done) {
5772 chunk->ecn_ce_done = 1;
5774 af = sctp_get_af_specific(
5775 ipver2af(ip_hdr(chunk->skb)->version));
5777 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5778 /* Do real work as sideffect. */
5779 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5784 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5786 /* The TSN is too high--silently discard the chunk and
5787 * count on it getting retransmitted later.
5789 return SCTP_IERROR_HIGH_TSN;
5790 } else if (tmp > 0) {
5791 /* This is a duplicate. Record it. */
5792 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5793 return SCTP_IERROR_DUP_TSN;
5796 /* This is a new TSN. */
5798 /* Discard if there is no room in the receive window.
5799 * Actually, allow a little bit of overflow (up to a MTU).
5801 datalen = ntohs(chunk->chunk_hdr->length);
5802 datalen -= sizeof(sctp_data_chunk_t);
5804 deliver = SCTP_CMD_CHUNK_ULP;
5806 /* Think about partial delivery. */
5807 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5809 /* Even if we don't accept this chunk there is
5812 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5815 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5816 * seems a bit troublesome in that frag_point varies based on
5817 * PMTU. In cases, such as loopback, this might be a rather
5820 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
5821 (datalen > asoc->rwnd + asoc->frag_point))) {
5823 /* If this is the next TSN, consider reneging to make
5824 * room. Note: Playing nice with a confused sender. A
5825 * malicious sender can still eat up all our buffer
5826 * space and in the future we may want to detect and
5827 * do more drastic reneging.
5829 if (sctp_tsnmap_has_gap(map) &&
5830 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5831 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5832 deliver = SCTP_CMD_RENEGE;
5834 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5835 "rwnd: %d\n", tsn, datalen,
5837 return SCTP_IERROR_IGNORE_TSN;
5842 * Also try to renege to limit our memory usage in the event that
5843 * we are under memory pressure
5844 * If we can't renege, don't worry about it, the sk_rmem_schedule
5845 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
5846 * memory usage too much
5848 if (*sk->sk_prot_creator->memory_pressure) {
5849 if (sctp_tsnmap_has_gap(map) &&
5850 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5851 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
5852 deliver = SCTP_CMD_RENEGE;
5857 * Section 3.3.10.9 No User Data (9)
5861 * No User Data: This error cause is returned to the originator of a
5862 * DATA chunk if a received DATA chunk has no user data.
5864 if (unlikely(0 == datalen)) {
5865 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5867 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5870 /* We are going to ABORT, so we might as well stop
5871 * processing the rest of the chunks in the packet.
5873 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
5874 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5875 SCTP_ERROR(ECONNABORTED));
5876 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5877 SCTP_PERR(SCTP_ERROR_NO_DATA));
5878 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5879 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5880 return SCTP_IERROR_NO_DATA;
5883 /* If definately accepting the DATA chunk, record its TSN, otherwise
5884 * wait for renege processing.
5886 if (SCTP_CMD_CHUNK_ULP == deliver)
5887 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5889 chunk->data_accepted = 1;
5891 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5892 * if we renege and the chunk arrives again.
5894 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5895 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5897 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5899 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5901 * If an endpoint receive a DATA chunk with an invalid stream
5902 * identifier, it shall acknowledge the reception of the DATA chunk
5903 * following the normal procedure, immediately send an ERROR chunk
5904 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5905 * and discard the DATA chunk.
5907 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5908 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5910 sizeof(data_hdr->stream));
5912 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5914 return SCTP_IERROR_BAD_STREAM;
5917 /* Send the data up to the user. Note: Schedule the
5918 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5919 * chunk needs the updated rwnd.
5921 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5923 return SCTP_IERROR_NO_ERROR;