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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
55 #include <linux/types.h>
56 #include <linux/kernel.h>
58 #include <linux/ipv6.h>
59 #include <linux/net.h>
60 #include <linux/inet.h>
61 #include <linux/slab.h>
63 #include <net/inet_ecn.h>
64 #include <linux/skbuff.h>
65 #include <net/sctp/sctp.h>
66 #include <net/sctp/sm.h>
67 #include <net/sctp/structs.h>
69 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
70 const struct sctp_association *asoc,
71 struct sctp_chunk *chunk,
74 static int sctp_eat_data(const struct sctp_association *asoc,
75 struct sctp_chunk *chunk,
76 sctp_cmd_seq_t *commands);
77 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
78 const struct sctp_chunk *chunk);
79 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
80 const struct sctp_association *asoc,
81 const struct sctp_chunk *chunk,
82 sctp_cmd_seq_t *commands,
83 struct sctp_chunk *err_chunk);
84 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
85 const struct sctp_association *asoc,
86 const sctp_subtype_t type,
88 sctp_cmd_seq_t *commands);
89 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
90 const struct sctp_association *asoc,
91 const sctp_subtype_t type,
93 sctp_cmd_seq_t *commands);
94 static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
95 const struct sctp_association *asoc,
96 const sctp_subtype_t type,
98 sctp_cmd_seq_t *commands);
99 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
101 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
102 __be16 error, int sk_err,
103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
106 static sctp_disposition_t sctp_sf_abort_violation(
107 const struct sctp_endpoint *ep,
108 const struct sctp_association *asoc,
110 sctp_cmd_seq_t *commands,
112 const size_t paylen);
114 static sctp_disposition_t sctp_sf_violation_chunklen(
115 const struct sctp_endpoint *ep,
116 const struct sctp_association *asoc,
117 const sctp_subtype_t type,
119 sctp_cmd_seq_t *commands);
121 static sctp_disposition_t sctp_sf_violation_paramlen(
122 const struct sctp_endpoint *ep,
123 const struct sctp_association *asoc,
124 const sctp_subtype_t type,
125 void *arg, void *ext,
126 sctp_cmd_seq_t *commands);
128 static sctp_disposition_t sctp_sf_violation_ctsn(
129 const struct sctp_endpoint *ep,
130 const struct sctp_association *asoc,
131 const sctp_subtype_t type,
133 sctp_cmd_seq_t *commands);
135 static sctp_disposition_t sctp_sf_violation_chunk(
136 const struct sctp_endpoint *ep,
137 const struct sctp_association *asoc,
138 const sctp_subtype_t type,
140 sctp_cmd_seq_t *commands);
142 static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
143 const struct sctp_association *asoc,
144 const sctp_subtype_t type,
145 struct sctp_chunk *chunk);
147 static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
148 const struct sctp_association *asoc,
149 const sctp_subtype_t type,
151 sctp_cmd_seq_t *commands);
153 /* Small helper function that checks if the chunk length
154 * is of the appropriate length. The 'required_length' argument
155 * is set to be the size of a specific chunk we are testing.
156 * Return Values: 1 = Valid length
161 sctp_chunk_length_valid(struct sctp_chunk *chunk,
162 __u16 required_length)
164 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
166 if (unlikely(chunk_length < required_length))
172 /**********************************************************
173 * These are the state functions for handling chunk events.
174 **********************************************************/
177 * Process the final SHUTDOWN COMPLETE.
179 * Section: 4 (C) (diagram), 9.2
180 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
181 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
182 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
183 * should stop the T2-shutdown timer and remove all knowledge of the
184 * association (and thus the association enters the CLOSED state).
186 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
187 * C) Rules for packet carrying SHUTDOWN COMPLETE:
189 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
190 * if the Verification Tag field of the packet matches its own tag and
191 * the T bit is not set
193 * it is set to its peer's tag and the T bit is set in the Chunk
195 * Otherwise, the receiver MUST silently discard the packet
196 * and take no further action. An endpoint MUST ignore the
197 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
200 * (endpoint, asoc, chunk)
203 * (asoc, reply_msg, msg_up, timers, counters)
205 * The return value is the disposition of the chunk.
207 sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
208 const struct sctp_association *asoc,
209 const sctp_subtype_t type,
211 sctp_cmd_seq_t *commands)
213 struct sctp_chunk *chunk = arg;
214 struct sctp_ulpevent *ev;
216 if (!sctp_vtag_verify_either(chunk, asoc))
217 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
219 /* RFC 2960 6.10 Bundling
221 * An endpoint MUST NOT bundle INIT, INIT ACK or
222 * SHUTDOWN COMPLETE with any other chunks.
224 if (!chunk->singleton)
225 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
227 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
228 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
229 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
232 /* RFC 2960 10.2 SCTP-to-ULP
234 * H) SHUTDOWN COMPLETE notification
236 * When SCTP completes the shutdown procedures (section 9.2) this
237 * notification is passed to the upper layer.
239 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
240 0, 0, 0, NULL, GFP_ATOMIC);
242 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
245 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
246 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
247 * not the chunk should be discarded. If the endpoint is in
248 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
249 * T2-shutdown timer and remove all knowledge of the
250 * association (and thus the association enters the CLOSED
253 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
256 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
257 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
259 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
260 SCTP_STATE(SCTP_STATE_CLOSED));
262 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
263 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
265 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
267 return SCTP_DISPOSITION_DELETE_TCB;
271 * Respond to a normal INIT chunk.
272 * We are the side that is being asked for an association.
274 * Section: 5.1 Normal Establishment of an Association, B
275 * B) "Z" shall respond immediately with an INIT ACK chunk. The
276 * destination IP address of the INIT ACK MUST be set to the source
277 * IP address of the INIT to which this INIT ACK is responding. In
278 * the response, besides filling in other parameters, "Z" must set the
279 * Verification Tag field to Tag_A, and also provide its own
280 * Verification Tag (Tag_Z) in the Initiate Tag field.
282 * Verification Tag: Must be 0.
285 * (endpoint, asoc, chunk)
288 * (asoc, reply_msg, msg_up, timers, counters)
290 * The return value is the disposition of the chunk.
292 sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
293 const struct sctp_association *asoc,
294 const sctp_subtype_t type,
296 sctp_cmd_seq_t *commands)
298 struct sctp_chunk *chunk = arg;
299 struct sctp_chunk *repl;
300 struct sctp_association *new_asoc;
301 struct sctp_chunk *err_chunk;
302 struct sctp_packet *packet;
303 sctp_unrecognized_param_t *unk_param;
307 * An endpoint MUST NOT bundle INIT, INIT ACK or
308 * SHUTDOWN COMPLETE with any other chunks.
311 * Furthermore, we require that the receiver of an INIT chunk MUST
312 * enforce these rules by silently discarding an arriving packet
313 * with an INIT chunk that is bundled with other chunks.
315 if (!chunk->singleton)
316 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
318 /* If the packet is an OOTB packet which is temporarily on the
319 * control endpoint, respond with an ABORT.
321 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
322 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
323 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
326 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
329 if (chunk->sctp_hdr->vtag != 0)
330 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
332 /* Make sure that the INIT chunk has a valid length.
333 * Normally, this would cause an ABORT with a Protocol Violation
334 * error, but since we don't have an association, we'll
335 * just discard the packet.
337 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
338 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
340 /* If the INIT is coming toward a closing socket, we'll send back
341 * and ABORT. Essentially, this catches the race of INIT being
342 * backloged to the socket at the same time as the user isses close().
343 * Since the socket and all its associations are going away, we
344 * can treat this OOTB
346 if (sctp_sstate(ep->base.sk, CLOSING))
347 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
349 /* Verify the INIT chunk before processing it. */
351 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
352 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
354 /* This chunk contains fatal error. It is to be discarded.
355 * Send an ABORT, with causes if there is any.
358 packet = sctp_abort_pkt_new(ep, asoc, arg,
359 (__u8 *)(err_chunk->chunk_hdr) +
360 sizeof(sctp_chunkhdr_t),
361 ntohs(err_chunk->chunk_hdr->length) -
362 sizeof(sctp_chunkhdr_t));
364 sctp_chunk_free(err_chunk);
367 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
368 SCTP_PACKET(packet));
369 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
370 return SCTP_DISPOSITION_CONSUME;
372 return SCTP_DISPOSITION_NOMEM;
375 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
380 /* Grab the INIT header. */
381 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
383 /* Tag the variable length parameters. */
384 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
386 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
390 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
391 sctp_scope(sctp_source(chunk)),
395 /* The call, sctp_process_init(), can fail on memory allocation. */
396 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
397 (sctp_init_chunk_t *)chunk->chunk_hdr,
401 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
403 /* If there are errors need to be reported for unknown parameters,
404 * make sure to reserve enough room in the INIT ACK for them.
408 len = ntohs(err_chunk->chunk_hdr->length) -
409 sizeof(sctp_chunkhdr_t);
411 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
415 /* If there are errors need to be reported for unknown parameters,
416 * include them in the outgoing INIT ACK as "Unrecognized parameter"
420 /* Get the "Unrecognized parameter" parameter(s) out of the
421 * ERROR chunk generated by sctp_verify_init(). Since the
422 * error cause code for "unknown parameter" and the
423 * "Unrecognized parameter" type is the same, we can
424 * construct the parameters in INIT ACK by copying the
427 unk_param = (sctp_unrecognized_param_t *)
428 ((__u8 *)(err_chunk->chunk_hdr) +
429 sizeof(sctp_chunkhdr_t));
430 /* Replace the cause code with the "Unrecognized parameter"
433 sctp_addto_chunk(repl, len, unk_param);
434 sctp_chunk_free(err_chunk);
437 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
439 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
442 * Note: After sending out INIT ACK with the State Cookie parameter,
443 * "Z" MUST NOT allocate any resources, nor keep any states for the
444 * new association. Otherwise, "Z" will be vulnerable to resource
447 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
449 return SCTP_DISPOSITION_DELETE_TCB;
452 sctp_association_free(new_asoc);
455 sctp_chunk_free(err_chunk);
456 return SCTP_DISPOSITION_NOMEM;
460 * Respond to a normal INIT ACK chunk.
461 * We are the side that is initiating the association.
463 * Section: 5.1 Normal Establishment of an Association, C
464 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
465 * timer and leave COOKIE-WAIT state. "A" shall then send the State
466 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
467 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
469 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
470 * DATA chunks, but it MUST be the first chunk in the packet and
471 * until the COOKIE ACK is returned the sender MUST NOT send any
472 * other packets to the peer.
474 * Verification Tag: 3.3.3
475 * If the value of the Initiate Tag in a received INIT ACK chunk is
476 * found to be 0, the receiver MUST treat it as an error and close the
477 * association by transmitting an ABORT.
480 * (endpoint, asoc, chunk)
483 * (asoc, reply_msg, msg_up, timers, counters)
485 * The return value is the disposition of the chunk.
487 sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
488 const struct sctp_association *asoc,
489 const sctp_subtype_t type,
491 sctp_cmd_seq_t *commands)
493 struct sctp_chunk *chunk = arg;
494 sctp_init_chunk_t *initchunk;
495 struct sctp_chunk *err_chunk;
496 struct sctp_packet *packet;
498 if (!sctp_vtag_verify(chunk, asoc))
499 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
502 * An endpoint MUST NOT bundle INIT, INIT ACK or
503 * SHUTDOWN COMPLETE with any other chunks.
505 if (!chunk->singleton)
506 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
508 /* Make sure that the INIT-ACK chunk has a valid length */
509 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
510 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
512 /* Grab the INIT header. */
513 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
515 /* Verify the INIT chunk before processing it. */
517 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
518 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
521 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
523 /* This chunk contains fatal error. It is to be discarded.
524 * Send an ABORT, with causes. If there are no causes,
525 * then there wasn't enough memory. Just terminate
529 packet = sctp_abort_pkt_new(ep, asoc, arg,
530 (__u8 *)(err_chunk->chunk_hdr) +
531 sizeof(sctp_chunkhdr_t),
532 ntohs(err_chunk->chunk_hdr->length) -
533 sizeof(sctp_chunkhdr_t));
535 sctp_chunk_free(err_chunk);
538 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
539 SCTP_PACKET(packet));
540 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
541 error = SCTP_ERROR_INV_PARAM;
545 /* SCTP-AUTH, Section 6.3:
546 * It should be noted that if the receiver wants to tear
547 * down an association in an authenticated way only, the
548 * handling of malformed packets should not result in
549 * tearing down the association.
551 * This means that if we only want to abort associations
552 * in an authenticated way (i.e AUTH+ABORT), then we
553 * can't destroy this association just because the packet
556 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
557 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
559 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
560 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
561 asoc, chunk->transport);
564 /* Tag the variable length parameters. Note that we never
565 * convert the parameters in an INIT chunk.
567 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
569 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
571 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
572 SCTP_PEER_INIT(initchunk));
574 /* Reset init error count upon receipt of INIT-ACK. */
575 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
577 /* 5.1 C) "A" shall stop the T1-init timer and leave
578 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
579 * timer, and enter the COOKIE-ECHOED state.
581 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
582 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
583 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
584 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
585 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
586 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
588 /* SCTP-AUTH: genereate the assocition shared keys so that
589 * we can potentially signe the COOKIE-ECHO.
591 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
593 /* 5.1 C) "A" shall then send the State Cookie received in the
594 * INIT ACK chunk in a COOKIE ECHO chunk, ...
596 /* If there is any errors to report, send the ERROR chunk generated
597 * for unknown parameters as well.
599 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
600 SCTP_CHUNK(err_chunk));
602 return SCTP_DISPOSITION_CONSUME;
606 * Respond to a normal COOKIE ECHO chunk.
607 * We are the side that is being asked for an association.
609 * Section: 5.1 Normal Establishment of an Association, D
610 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
611 * with a COOKIE ACK chunk after building a TCB and moving to
612 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
613 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
614 * chunk MUST be the first chunk in the packet.
616 * IMPLEMENTATION NOTE: An implementation may choose to send the
617 * Communication Up notification to the SCTP user upon reception
618 * of a valid COOKIE ECHO chunk.
620 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
621 * D) Rules for packet carrying a COOKIE ECHO
623 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
624 * Initial Tag received in the INIT ACK.
626 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
629 * (endpoint, asoc, chunk)
632 * (asoc, reply_msg, msg_up, timers, counters)
634 * The return value is the disposition of the chunk.
636 sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
637 const struct sctp_association *asoc,
638 const sctp_subtype_t type, void *arg,
639 sctp_cmd_seq_t *commands)
641 struct sctp_chunk *chunk = arg;
642 struct sctp_association *new_asoc;
643 sctp_init_chunk_t *peer_init;
644 struct sctp_chunk *repl;
645 struct sctp_ulpevent *ev, *ai_ev = NULL;
647 struct sctp_chunk *err_chk_p;
650 /* If the packet is an OOTB packet which is temporarily on the
651 * control endpoint, respond with an ABORT.
653 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
654 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
655 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
658 /* Make sure that the COOKIE_ECHO chunk has a valid length.
659 * In this case, we check that we have enough for at least a
660 * chunk header. More detailed verification is done
661 * in sctp_unpack_cookie().
663 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
664 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
666 /* If the endpoint is not listening or if the number of associations
667 * on the TCP-style socket exceed the max backlog, respond with an
671 if (!sctp_sstate(sk, LISTENING) ||
672 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
673 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
675 /* "Decode" the chunk. We have no optional parameters so we
678 chunk->subh.cookie_hdr =
679 (struct sctp_signed_cookie *)chunk->skb->data;
680 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
681 sizeof(sctp_chunkhdr_t)))
684 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
685 * "Z" will reply with a COOKIE ACK chunk after building a TCB
686 * and moving to the ESTABLISHED state.
688 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
692 * If the re-build failed, what is the proper error path
695 * [We should abort the association. --piggy]
698 /* FIXME: Several errors are possible. A bad cookie should
699 * be silently discarded, but think about logging it too.
702 case -SCTP_IERROR_NOMEM:
705 case -SCTP_IERROR_STALE_COOKIE:
706 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
708 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
710 case -SCTP_IERROR_BAD_SIG:
712 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
717 /* Delay state machine commands until later.
719 * Re-build the bind address for the association is done in
720 * the sctp_unpack_cookie() already.
722 /* This is a brand-new association, so these are not yet side
723 * effects--it is safe to run them here.
725 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
727 if (!sctp_process_init(new_asoc, chunk,
728 &chunk->subh.cookie_hdr->c.peer_addr,
729 peer_init, GFP_ATOMIC))
732 /* SCTP-AUTH: Now that we've populate required fields in
733 * sctp_process_init, set up the assocaition shared keys as
734 * necessary so that we can potentially authenticate the ACK
736 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
740 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
741 * is supposed to be authenticated and we have to do delayed
742 * authentication. We've just recreated the association using
743 * the information in the cookie and now it's much easier to
744 * do the authentication.
746 if (chunk->auth_chunk) {
747 struct sctp_chunk auth;
750 /* Make sure that we and the peer are AUTH capable */
751 if (!sctp_auth_enable || !new_asoc->peer.auth_capable) {
752 sctp_association_free(new_asoc);
753 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
756 /* set-up our fake chunk so that we can process it */
757 auth.skb = chunk->auth_chunk;
758 auth.asoc = chunk->asoc;
759 auth.sctp_hdr = chunk->sctp_hdr;
760 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
761 sizeof(sctp_chunkhdr_t));
762 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
763 auth.transport = chunk->transport;
765 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
766 if (ret != SCTP_IERROR_NO_ERROR) {
767 sctp_association_free(new_asoc);
768 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
772 repl = sctp_make_cookie_ack(new_asoc, chunk);
776 /* RFC 2960 5.1 Normal Establishment of an Association
778 * D) IMPLEMENTATION NOTE: An implementation may choose to
779 * send the Communication Up notification to the SCTP user
780 * upon reception of a valid COOKIE ECHO chunk.
782 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
783 new_asoc->c.sinit_num_ostreams,
784 new_asoc->c.sinit_max_instreams,
789 /* Sockets API Draft Section 5.3.1.6
790 * When a peer sends a Adaptation Layer Indication parameter , SCTP
791 * delivers this notification to inform the application that of the
792 * peers requested adaptation layer.
794 if (new_asoc->peer.adaptation_ind) {
795 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
801 /* Add all the state machine commands now since we've created
802 * everything. This way we don't introduce memory corruptions
803 * during side-effect processing and correclty count established
806 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
807 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
808 SCTP_STATE(SCTP_STATE_ESTABLISHED));
809 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
810 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
811 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
813 if (new_asoc->autoclose)
814 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
815 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
817 /* This will send the COOKIE ACK */
818 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
820 /* Queue the ASSOC_CHANGE event */
821 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
823 /* Send up the Adaptation Layer Indication event */
825 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
826 SCTP_ULPEVENT(ai_ev));
828 return SCTP_DISPOSITION_CONSUME;
831 sctp_ulpevent_free(ev);
833 sctp_chunk_free(repl);
835 sctp_association_free(new_asoc);
837 return SCTP_DISPOSITION_NOMEM;
841 * Respond to a normal COOKIE ACK chunk.
842 * We are the side that is being asked for an association.
844 * RFC 2960 5.1 Normal Establishment of an Association
846 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
847 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
848 * timer. It may also notify its ULP about the successful
849 * establishment of the association with a Communication Up
850 * notification (see Section 10).
854 * (endpoint, asoc, chunk)
857 * (asoc, reply_msg, msg_up, timers, counters)
859 * The return value is the disposition of the chunk.
861 sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
862 const struct sctp_association *asoc,
863 const sctp_subtype_t type, void *arg,
864 sctp_cmd_seq_t *commands)
866 struct sctp_chunk *chunk = arg;
867 struct sctp_ulpevent *ev;
869 if (!sctp_vtag_verify(chunk, asoc))
870 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
872 /* Verify that the chunk length for the COOKIE-ACK is OK.
873 * If we don't do this, any bundled chunks may be junked.
875 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
876 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
879 /* Reset init error count upon receipt of COOKIE-ACK,
880 * to avoid problems with the managemement of this
881 * counter in stale cookie situations when a transition back
882 * from the COOKIE-ECHOED state to the COOKIE-WAIT
883 * state is performed.
885 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
887 /* RFC 2960 5.1 Normal Establishment of an Association
889 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
890 * from the COOKIE-ECHOED state to the ESTABLISHED state,
891 * stopping the T1-cookie timer.
893 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
894 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
895 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
896 SCTP_STATE(SCTP_STATE_ESTABLISHED));
897 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
898 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
899 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
901 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
902 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
904 /* It may also notify its ULP about the successful
905 * establishment of the association with a Communication Up
906 * notification (see Section 10).
908 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
909 0, asoc->c.sinit_num_ostreams,
910 asoc->c.sinit_max_instreams,
916 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
918 /* Sockets API Draft Section 5.3.1.6
919 * When a peer sends a Adaptation Layer Indication parameter , SCTP
920 * delivers this notification to inform the application that of the
921 * peers requested adaptation layer.
923 if (asoc->peer.adaptation_ind) {
924 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
928 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
932 return SCTP_DISPOSITION_CONSUME;
934 return SCTP_DISPOSITION_NOMEM;
937 /* Generate and sendout a heartbeat packet. */
938 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
939 const struct sctp_association *asoc,
940 const sctp_subtype_t type,
942 sctp_cmd_seq_t *commands)
944 struct sctp_transport *transport = (struct sctp_transport *) arg;
945 struct sctp_chunk *reply;
947 /* Send a heartbeat to our peer. */
948 reply = sctp_make_heartbeat(asoc, transport);
950 return SCTP_DISPOSITION_NOMEM;
952 /* Set rto_pending indicating that an RTT measurement
953 * is started with this heartbeat chunk.
955 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
956 SCTP_TRANSPORT(transport));
958 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
959 return SCTP_DISPOSITION_CONSUME;
962 /* Generate a HEARTBEAT packet on the given transport. */
963 sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
964 const struct sctp_association *asoc,
965 const sctp_subtype_t type,
967 sctp_cmd_seq_t *commands)
969 struct sctp_transport *transport = (struct sctp_transport *) arg;
971 if (asoc->overall_error_count >= asoc->max_retrans) {
972 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
973 SCTP_ERROR(ETIMEDOUT));
974 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
975 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
976 SCTP_PERR(SCTP_ERROR_NO_ERROR));
977 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
978 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
979 return SCTP_DISPOSITION_DELETE_TCB;
983 * The Sender-specific Heartbeat Info field should normally include
984 * information about the sender's current time when this HEARTBEAT
985 * chunk is sent and the destination transport address to which this
986 * HEARTBEAT is sent (see Section 8.3).
989 if (transport->param_flags & SPP_HB_ENABLE) {
990 if (SCTP_DISPOSITION_NOMEM ==
991 sctp_sf_heartbeat(ep, asoc, type, arg,
993 return SCTP_DISPOSITION_NOMEM;
995 /* Set transport error counter and association error counter
996 * when sending heartbeat.
998 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
999 SCTP_TRANSPORT(transport));
1001 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1002 SCTP_TRANSPORT(transport));
1003 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1004 SCTP_TRANSPORT(transport));
1006 return SCTP_DISPOSITION_CONSUME;
1010 * Process an heartbeat request.
1012 * Section: 8.3 Path Heartbeat
1013 * The receiver of the HEARTBEAT should immediately respond with a
1014 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1015 * from the received HEARTBEAT chunk.
1017 * Verification Tag: 8.5 Verification Tag [Normal verification]
1018 * When receiving an SCTP packet, the endpoint MUST ensure that the
1019 * value in the Verification Tag field of the received SCTP packet
1020 * matches its own Tag. If the received Verification Tag value does not
1021 * match the receiver's own tag value, the receiver shall silently
1022 * discard the packet and shall not process it any further except for
1023 * those cases listed in Section 8.5.1 below.
1026 * (endpoint, asoc, chunk)
1029 * (asoc, reply_msg, msg_up, timers, counters)
1031 * The return value is the disposition of the chunk.
1033 sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1034 const struct sctp_association *asoc,
1035 const sctp_subtype_t type,
1037 sctp_cmd_seq_t *commands)
1039 struct sctp_chunk *chunk = arg;
1040 struct sctp_chunk *reply;
1043 if (!sctp_vtag_verify(chunk, asoc))
1044 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1046 /* Make sure that the HEARTBEAT chunk has a valid length. */
1047 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1048 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1051 /* 8.3 The receiver of the HEARTBEAT should immediately
1052 * respond with a HEARTBEAT ACK that contains the Heartbeat
1053 * Information field copied from the received HEARTBEAT chunk.
1055 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1056 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1057 if (!pskb_pull(chunk->skb, paylen))
1060 reply = sctp_make_heartbeat_ack(asoc, chunk,
1061 chunk->subh.hb_hdr, paylen);
1065 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1066 return SCTP_DISPOSITION_CONSUME;
1069 return SCTP_DISPOSITION_NOMEM;
1073 * Process the returning HEARTBEAT ACK.
1075 * Section: 8.3 Path Heartbeat
1076 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1077 * should clear the error counter of the destination transport
1078 * address to which the HEARTBEAT was sent, and mark the destination
1079 * transport address as active if it is not so marked. The endpoint may
1080 * optionally report to the upper layer when an inactive destination
1081 * address is marked as active due to the reception of the latest
1082 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1083 * clear the association overall error count as well (as defined
1086 * The receiver of the HEARTBEAT ACK should also perform an RTT
1087 * measurement for that destination transport address using the time
1088 * value carried in the HEARTBEAT ACK chunk.
1090 * Verification Tag: 8.5 Verification Tag [Normal verification]
1093 * (endpoint, asoc, chunk)
1096 * (asoc, reply_msg, msg_up, timers, counters)
1098 * The return value is the disposition of the chunk.
1100 sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1101 const struct sctp_association *asoc,
1102 const sctp_subtype_t type,
1104 sctp_cmd_seq_t *commands)
1106 struct sctp_chunk *chunk = arg;
1107 union sctp_addr from_addr;
1108 struct sctp_transport *link;
1109 sctp_sender_hb_info_t *hbinfo;
1110 unsigned long max_interval;
1112 if (!sctp_vtag_verify(chunk, asoc))
1113 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1115 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1116 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1117 sizeof(sctp_sender_hb_info_t)))
1118 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1121 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1122 /* Make sure that the length of the parameter is what we expect */
1123 if (ntohs(hbinfo->param_hdr.length) !=
1124 sizeof(sctp_sender_hb_info_t)) {
1125 return SCTP_DISPOSITION_DISCARD;
1128 from_addr = hbinfo->daddr;
1129 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1131 /* This should never happen, but lets log it if so. */
1132 if (unlikely(!link)) {
1133 if (from_addr.sa.sa_family == AF_INET6) {
1134 if (net_ratelimit())
1135 pr_warn("%s association %p could not find address %pI6\n",
1138 &from_addr.v6.sin6_addr);
1140 if (net_ratelimit())
1141 pr_warn("%s association %p could not find address %pI4\n",
1144 &from_addr.v4.sin_addr.s_addr);
1146 return SCTP_DISPOSITION_DISCARD;
1149 /* Validate the 64-bit random nonce. */
1150 if (hbinfo->hb_nonce != link->hb_nonce)
1151 return SCTP_DISPOSITION_DISCARD;
1153 max_interval = link->hbinterval + link->rto;
1155 /* Check if the timestamp looks valid. */
1156 if (time_after(hbinfo->sent_at, jiffies) ||
1157 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1158 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1159 "received for transport: %p\n",
1161 return SCTP_DISPOSITION_DISCARD;
1164 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1165 * the HEARTBEAT should clear the error counter of the
1166 * destination transport address to which the HEARTBEAT was
1167 * sent and mark the destination transport address as active if
1168 * it is not so marked.
1170 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1172 return SCTP_DISPOSITION_CONSUME;
1175 /* Helper function to send out an abort for the restart
1178 static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1179 struct sctp_chunk *init,
1180 sctp_cmd_seq_t *commands)
1183 struct sctp_packet *pkt;
1184 union sctp_addr_param *addrparm;
1185 struct sctp_errhdr *errhdr;
1186 struct sctp_endpoint *ep;
1187 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1188 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1190 /* Build the error on the stack. We are way to malloc crazy
1191 * throughout the code today.
1193 errhdr = (struct sctp_errhdr *)buffer;
1194 addrparm = (union sctp_addr_param *)errhdr->variable;
1196 /* Copy into a parm format. */
1197 len = af->to_addr_param(ssa, addrparm);
1198 len += sizeof(sctp_errhdr_t);
1200 errhdr->cause = SCTP_ERROR_RESTART;
1201 errhdr->length = htons(len);
1203 /* Assign to the control socket. */
1204 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1206 /* Association is NULL since this may be a restart attack and we
1207 * want to send back the attacker's vtag.
1209 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1213 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1215 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1217 /* Discard the rest of the inbound packet. */
1218 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1221 /* Even if there is no memory, treat as a failure so
1222 * the packet will get dropped.
1227 static bool list_has_sctp_addr(const struct list_head *list,
1228 union sctp_addr *ipaddr)
1230 struct sctp_transport *addr;
1232 list_for_each_entry(addr, list, transports) {
1233 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1239 /* A restart is occurring, check to make sure no new addresses
1240 * are being added as we may be under a takeover attack.
1242 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1243 const struct sctp_association *asoc,
1244 struct sctp_chunk *init,
1245 sctp_cmd_seq_t *commands)
1247 struct sctp_transport *new_addr;
1250 /* Implementor's Guide - Section 5.2.2
1252 * Before responding the endpoint MUST check to see if the
1253 * unexpected INIT adds new addresses to the association. If new
1254 * addresses are added to the association, the endpoint MUST respond
1258 /* Search through all current addresses and make sure
1259 * we aren't adding any new ones.
1261 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1263 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1264 &new_addr->ipaddr)) {
1265 sctp_sf_send_restart_abort(&new_addr->ipaddr, init,
1272 /* Return success if all addresses were found. */
1276 /* Populate the verification/tie tags based on overlapping INIT
1279 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1281 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1282 const struct sctp_association *asoc)
1284 switch (asoc->state) {
1286 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1288 case SCTP_STATE_COOKIE_WAIT:
1289 new_asoc->c.my_vtag = asoc->c.my_vtag;
1290 new_asoc->c.my_ttag = asoc->c.my_vtag;
1291 new_asoc->c.peer_ttag = 0;
1294 case SCTP_STATE_COOKIE_ECHOED:
1295 new_asoc->c.my_vtag = asoc->c.my_vtag;
1296 new_asoc->c.my_ttag = asoc->c.my_vtag;
1297 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1300 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1301 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1304 new_asoc->c.my_ttag = asoc->c.my_vtag;
1305 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1309 /* Other parameters for the endpoint SHOULD be copied from the
1310 * existing parameters of the association (e.g. number of
1311 * outbound streams) into the INIT ACK and cookie.
1313 new_asoc->rwnd = asoc->rwnd;
1314 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1315 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1316 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1320 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1323 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1325 * Returns value representing action to be taken. These action values
1326 * correspond to Action/Description values in RFC 2960, Table 2.
1328 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1329 const struct sctp_association *asoc)
1331 /* In this case, the peer may have restarted. */
1332 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1333 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1334 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1335 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1338 /* Collision case B. */
1339 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1340 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1341 (0 == asoc->c.peer_vtag))) {
1345 /* Collision case D. */
1346 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1347 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1350 /* Collision case C. */
1351 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1352 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1353 (0 == new_asoc->c.my_ttag) &&
1354 (0 == new_asoc->c.peer_ttag))
1357 /* No match to any of the special cases; discard this packet. */
1361 /* Common helper routine for both duplicate and simulataneous INIT
1364 static sctp_disposition_t sctp_sf_do_unexpected_init(
1365 const struct sctp_endpoint *ep,
1366 const struct sctp_association *asoc,
1367 const sctp_subtype_t type,
1368 void *arg, sctp_cmd_seq_t *commands)
1370 sctp_disposition_t retval;
1371 struct sctp_chunk *chunk = arg;
1372 struct sctp_chunk *repl;
1373 struct sctp_association *new_asoc;
1374 struct sctp_chunk *err_chunk;
1375 struct sctp_packet *packet;
1376 sctp_unrecognized_param_t *unk_param;
1380 * An endpoint MUST NOT bundle INIT, INIT ACK or
1381 * SHUTDOWN COMPLETE with any other chunks.
1384 * Furthermore, we require that the receiver of an INIT chunk MUST
1385 * enforce these rules by silently discarding an arriving packet
1386 * with an INIT chunk that is bundled with other chunks.
1388 if (!chunk->singleton)
1389 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1391 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1394 if (chunk->sctp_hdr->vtag != 0)
1395 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1397 /* Make sure that the INIT chunk has a valid length.
1398 * In this case, we generate a protocol violation since we have
1399 * an association established.
1401 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1402 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1404 /* Grab the INIT header. */
1405 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1407 /* Tag the variable length parameters. */
1408 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1410 /* Verify the INIT chunk before processing it. */
1412 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1413 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1415 /* This chunk contains fatal error. It is to be discarded.
1416 * Send an ABORT, with causes if there is any.
1419 packet = sctp_abort_pkt_new(ep, asoc, arg,
1420 (__u8 *)(err_chunk->chunk_hdr) +
1421 sizeof(sctp_chunkhdr_t),
1422 ntohs(err_chunk->chunk_hdr->length) -
1423 sizeof(sctp_chunkhdr_t));
1426 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1427 SCTP_PACKET(packet));
1428 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1429 retval = SCTP_DISPOSITION_CONSUME;
1431 retval = SCTP_DISPOSITION_NOMEM;
1435 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1441 * Other parameters for the endpoint SHOULD be copied from the
1442 * existing parameters of the association (e.g. number of
1443 * outbound streams) into the INIT ACK and cookie.
1444 * FIXME: We are copying parameters from the endpoint not the
1447 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1451 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1452 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1455 /* In the outbound INIT ACK the endpoint MUST copy its current
1456 * Verification Tag and Peers Verification tag into a reserved
1457 * place (local tie-tag and per tie-tag) within the state cookie.
1459 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1460 (sctp_init_chunk_t *)chunk->chunk_hdr,
1464 /* Make sure no new addresses are being added during the
1465 * restart. Do not do this check for COOKIE-WAIT state,
1466 * since there are no peer addresses to check against.
1467 * Upon return an ABORT will have been sent if needed.
1469 if (!sctp_state(asoc, COOKIE_WAIT)) {
1470 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1472 retval = SCTP_DISPOSITION_CONSUME;
1477 sctp_tietags_populate(new_asoc, asoc);
1479 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1481 /* If there are errors need to be reported for unknown parameters,
1482 * make sure to reserve enough room in the INIT ACK for them.
1486 len = ntohs(err_chunk->chunk_hdr->length) -
1487 sizeof(sctp_chunkhdr_t);
1490 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1494 /* If there are errors need to be reported for unknown parameters,
1495 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1499 /* Get the "Unrecognized parameter" parameter(s) out of the
1500 * ERROR chunk generated by sctp_verify_init(). Since the
1501 * error cause code for "unknown parameter" and the
1502 * "Unrecognized parameter" type is the same, we can
1503 * construct the parameters in INIT ACK by copying the
1504 * ERROR causes over.
1506 unk_param = (sctp_unrecognized_param_t *)
1507 ((__u8 *)(err_chunk->chunk_hdr) +
1508 sizeof(sctp_chunkhdr_t));
1509 /* Replace the cause code with the "Unrecognized parameter"
1512 sctp_addto_chunk(repl, len, unk_param);
1515 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1516 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1519 * Note: After sending out INIT ACK with the State Cookie parameter,
1520 * "Z" MUST NOT allocate any resources for this new association.
1521 * Otherwise, "Z" will be vulnerable to resource attacks.
1523 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1524 retval = SCTP_DISPOSITION_CONSUME;
1529 retval = SCTP_DISPOSITION_NOMEM;
1532 sctp_association_free(new_asoc);
1535 sctp_chunk_free(err_chunk);
1540 * Handle simultaneous INIT.
1541 * This means we started an INIT and then we got an INIT request from
1544 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1545 * This usually indicates an initialization collision, i.e., each
1546 * endpoint is attempting, at about the same time, to establish an
1547 * association with the other endpoint.
1549 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1550 * endpoint MUST respond with an INIT ACK using the same parameters it
1551 * sent in its original INIT chunk (including its Verification Tag,
1552 * unchanged). These original parameters are combined with those from the
1553 * newly received INIT chunk. The endpoint shall also generate a State
1554 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1555 * INIT to calculate the State Cookie.
1557 * After that, the endpoint MUST NOT change its state, the T1-init
1558 * timer shall be left running and the corresponding TCB MUST NOT be
1559 * destroyed. The normal procedures for handling State Cookies when
1560 * a TCB exists will resolve the duplicate INITs to a single association.
1562 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1563 * its Tie-Tags with the Tag information of itself and its peer (see
1564 * section 5.2.2 for a description of the Tie-Tags).
1566 * Verification Tag: Not explicit, but an INIT can not have a valid
1567 * verification tag, so we skip the check.
1570 * (endpoint, asoc, chunk)
1573 * (asoc, reply_msg, msg_up, timers, counters)
1575 * The return value is the disposition of the chunk.
1577 sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1578 const struct sctp_association *asoc,
1579 const sctp_subtype_t type,
1581 sctp_cmd_seq_t *commands)
1583 /* Call helper to do the real work for both simulataneous and
1584 * duplicate INIT chunk handling.
1586 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1590 * Handle duplicated INIT messages. These are usually delayed
1593 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1594 * COOKIE-ECHOED and COOKIE-WAIT
1596 * Unless otherwise stated, upon reception of an unexpected INIT for
1597 * this association, the endpoint shall generate an INIT ACK with a
1598 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1599 * current Verification Tag and peer's Verification Tag into a reserved
1600 * place within the state cookie. We shall refer to these locations as
1601 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1602 * containing this INIT ACK MUST carry a Verification Tag value equal to
1603 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1604 * MUST contain a new Initiation Tag (randomly generated see Section
1605 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1606 * existing parameters of the association (e.g. number of outbound
1607 * streams) into the INIT ACK and cookie.
1609 * After sending out the INIT ACK, the endpoint shall take no further
1610 * actions, i.e., the existing association, including its current state,
1611 * and the corresponding TCB MUST NOT be changed.
1613 * Note: Only when a TCB exists and the association is not in a COOKIE-
1614 * WAIT state are the Tie-Tags populated. For a normal association INIT
1615 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1616 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1617 * State Cookie are populated as specified in section 5.2.1.
1619 * Verification Tag: Not specified, but an INIT has no way of knowing
1620 * what the verification tag could be, so we ignore it.
1623 * (endpoint, asoc, chunk)
1626 * (asoc, reply_msg, msg_up, timers, counters)
1628 * The return value is the disposition of the chunk.
1630 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1631 const struct sctp_association *asoc,
1632 const sctp_subtype_t type,
1634 sctp_cmd_seq_t *commands)
1636 /* Call helper to do the real work for both simulataneous and
1637 * duplicate INIT chunk handling.
1639 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1644 * Unexpected INIT-ACK handler.
1647 * If an INIT ACK received by an endpoint in any state other than the
1648 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1649 * An unexpected INIT ACK usually indicates the processing of an old or
1650 * duplicated INIT chunk.
1652 sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1653 const struct sctp_association *asoc,
1654 const sctp_subtype_t type,
1655 void *arg, sctp_cmd_seq_t *commands)
1657 /* Per the above section, we'll discard the chunk if we have an
1658 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1660 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
1661 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1663 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1666 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1669 * A) In this case, the peer may have restarted.
1671 static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1672 const struct sctp_association *asoc,
1673 struct sctp_chunk *chunk,
1674 sctp_cmd_seq_t *commands,
1675 struct sctp_association *new_asoc)
1677 sctp_init_chunk_t *peer_init;
1678 struct sctp_ulpevent *ev;
1679 struct sctp_chunk *repl;
1680 struct sctp_chunk *err;
1681 sctp_disposition_t disposition;
1683 /* new_asoc is a brand-new association, so these are not yet
1684 * side effects--it is safe to run them here.
1686 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1688 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1692 /* Make sure no new addresses are being added during the
1693 * restart. Though this is a pretty complicated attack
1694 * since you'd have to get inside the cookie.
1696 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1697 return SCTP_DISPOSITION_CONSUME;
1700 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1701 * the peer has restarted (Action A), it MUST NOT setup a new
1702 * association but instead resend the SHUTDOWN ACK and send an ERROR
1703 * chunk with a "Cookie Received while Shutting Down" error cause to
1706 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1707 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1708 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1710 if (SCTP_DISPOSITION_NOMEM == disposition)
1713 err = sctp_make_op_error(asoc, chunk,
1714 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1717 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1720 return SCTP_DISPOSITION_CONSUME;
1723 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1724 * data. Consider the optional choice of resending of this data.
1726 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1727 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1728 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1729 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1731 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1732 * and ASCONF-ACK cache.
1734 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1735 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1736 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1738 repl = sctp_make_cookie_ack(new_asoc, chunk);
1742 /* Report association restart to upper layer. */
1743 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1744 new_asoc->c.sinit_num_ostreams,
1745 new_asoc->c.sinit_max_instreams,
1750 /* Update the content of current association. */
1751 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1752 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1753 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1754 return SCTP_DISPOSITION_CONSUME;
1757 sctp_chunk_free(repl);
1759 return SCTP_DISPOSITION_NOMEM;
1762 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1765 * B) In this case, both sides may be attempting to start an association
1766 * at about the same time but the peer endpoint started its INIT
1767 * after responding to the local endpoint's INIT
1769 /* This case represents an initialization collision. */
1770 static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1771 const struct sctp_association *asoc,
1772 struct sctp_chunk *chunk,
1773 sctp_cmd_seq_t *commands,
1774 struct sctp_association *new_asoc)
1776 sctp_init_chunk_t *peer_init;
1777 struct sctp_chunk *repl;
1779 /* new_asoc is a brand-new association, so these are not yet
1780 * side effects--it is safe to run them here.
1782 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1783 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1787 /* Update the content of current association. */
1788 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1789 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1790 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1791 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1792 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1794 repl = sctp_make_cookie_ack(new_asoc, chunk);
1798 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1800 /* RFC 2960 5.1 Normal Establishment of an Association
1802 * D) IMPLEMENTATION NOTE: An implementation may choose to
1803 * send the Communication Up notification to the SCTP user
1804 * upon reception of a valid COOKIE ECHO chunk.
1806 * Sadly, this needs to be implemented as a side-effect, because
1807 * we are not guaranteed to have set the association id of the real
1808 * association and so these notifications need to be delayed until
1809 * the association id is allocated.
1812 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1814 /* Sockets API Draft Section 5.3.1.6
1815 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1816 * delivers this notification to inform the application that of the
1817 * peers requested adaptation layer.
1819 * This also needs to be done as a side effect for the same reason as
1822 if (asoc->peer.adaptation_ind)
1823 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1825 return SCTP_DISPOSITION_CONSUME;
1828 return SCTP_DISPOSITION_NOMEM;
1831 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1834 * C) In this case, the local endpoint's cookie has arrived late.
1835 * Before it arrived, the local endpoint sent an INIT and received an
1836 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1837 * but a new tag of its own.
1839 /* This case represents an initialization collision. */
1840 static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1841 const struct sctp_association *asoc,
1842 struct sctp_chunk *chunk,
1843 sctp_cmd_seq_t *commands,
1844 struct sctp_association *new_asoc)
1846 /* The cookie should be silently discarded.
1847 * The endpoint SHOULD NOT change states and should leave
1848 * any timers running.
1850 return SCTP_DISPOSITION_DISCARD;
1853 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1857 * D) When both local and remote tags match the endpoint should always
1858 * enter the ESTABLISHED state, if it has not already done so.
1860 /* This case represents an initialization collision. */
1861 static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1862 const struct sctp_association *asoc,
1863 struct sctp_chunk *chunk,
1864 sctp_cmd_seq_t *commands,
1865 struct sctp_association *new_asoc)
1867 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1868 struct sctp_chunk *repl;
1870 /* Clarification from Implementor's Guide:
1871 * D) When both local and remote tags match the endpoint should
1872 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1873 * It should stop any cookie timer that may be running and send
1877 /* Don't accidentally move back into established state. */
1878 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1879 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1880 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1881 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1882 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1883 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1884 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1887 /* RFC 2960 5.1 Normal Establishment of an Association
1889 * D) IMPLEMENTATION NOTE: An implementation may choose
1890 * to send the Communication Up notification to the
1891 * SCTP user upon reception of a valid COOKIE
1894 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1896 asoc->c.sinit_num_ostreams,
1897 asoc->c.sinit_max_instreams,
1902 /* Sockets API Draft Section 5.3.1.6
1903 * When a peer sends a Adaptation Layer Indication parameter,
1904 * SCTP delivers this notification to inform the application
1905 * that of the peers requested adaptation layer.
1907 if (asoc->peer.adaptation_ind) {
1908 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1916 repl = sctp_make_cookie_ack(new_asoc, chunk);
1920 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1923 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1926 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1927 SCTP_ULPEVENT(ai_ev));
1929 return SCTP_DISPOSITION_CONSUME;
1933 sctp_ulpevent_free(ai_ev);
1935 sctp_ulpevent_free(ev);
1936 return SCTP_DISPOSITION_NOMEM;
1940 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1941 * chunk was retransmitted and then delayed in the network.
1943 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1945 * Verification Tag: None. Do cookie validation.
1948 * (endpoint, asoc, chunk)
1951 * (asoc, reply_msg, msg_up, timers, counters)
1953 * The return value is the disposition of the chunk.
1955 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1956 const struct sctp_association *asoc,
1957 const sctp_subtype_t type,
1959 sctp_cmd_seq_t *commands)
1961 sctp_disposition_t retval;
1962 struct sctp_chunk *chunk = arg;
1963 struct sctp_association *new_asoc;
1966 struct sctp_chunk *err_chk_p;
1968 /* Make sure that the chunk has a valid length from the protocol
1969 * perspective. In this case check to make sure we have at least
1970 * enough for the chunk header. Cookie length verification is
1973 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1974 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1977 /* "Decode" the chunk. We have no optional parameters so we
1978 * are in good shape.
1980 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
1981 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1982 sizeof(sctp_chunkhdr_t)))
1985 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1986 * of a duplicate COOKIE ECHO match the Verification Tags of the
1987 * current association, consider the State Cookie valid even if
1988 * the lifespan is exceeded.
1990 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1994 * If the re-build failed, what is the proper error path
1997 * [We should abort the association. --piggy]
2000 /* FIXME: Several errors are possible. A bad cookie should
2001 * be silently discarded, but think about logging it too.
2004 case -SCTP_IERROR_NOMEM:
2007 case -SCTP_IERROR_STALE_COOKIE:
2008 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2010 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2011 case -SCTP_IERROR_BAD_SIG:
2013 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2017 /* Compare the tie_tag in cookie with the verification tag of
2018 * current association.
2020 action = sctp_tietags_compare(new_asoc, asoc);
2023 case 'A': /* Association restart. */
2024 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2028 case 'B': /* Collision case B. */
2029 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2033 case 'C': /* Collision case C. */
2034 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2038 case 'D': /* Collision case D. */
2039 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2043 default: /* Discard packet for all others. */
2044 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2048 /* Delete the tempory new association. */
2049 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2050 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2052 /* Restore association pointer to provide SCTP command interpeter
2053 * with a valid context in case it needs to manipulate
2055 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2056 SCTP_ASOC((struct sctp_association *)asoc));
2061 return SCTP_DISPOSITION_NOMEM;
2065 * Process an ABORT. (SHUTDOWN-PENDING state)
2067 * See sctp_sf_do_9_1_abort().
2069 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2070 const struct sctp_endpoint *ep,
2071 const struct sctp_association *asoc,
2072 const sctp_subtype_t type,
2074 sctp_cmd_seq_t *commands)
2076 struct sctp_chunk *chunk = arg;
2078 if (!sctp_vtag_verify_either(chunk, asoc))
2079 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2081 /* Make sure that the ABORT chunk has a valid length.
2082 * Since this is an ABORT chunk, we have to discard it
2083 * because of the following text:
2084 * RFC 2960, Section 3.3.7
2085 * If an endpoint receives an ABORT with a format error or for an
2086 * association that doesn't exist, it MUST silently discard it.
2087 * Because the length is "invalid", we can't really discard just
2088 * as we do not know its true length. So, to be safe, discard the
2091 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2092 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2094 /* ADD-IP: Special case for ABORT chunks
2095 * F4) One special consideration is that ABORT Chunks arriving
2096 * destined to the IP address being deleted MUST be
2097 * ignored (see Section 5.3.1 for further details).
2099 if (SCTP_ADDR_DEL ==
2100 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2101 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2103 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2107 * Process an ABORT. (SHUTDOWN-SENT state)
2109 * See sctp_sf_do_9_1_abort().
2111 sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2112 const struct sctp_association *asoc,
2113 const sctp_subtype_t type,
2115 sctp_cmd_seq_t *commands)
2117 struct sctp_chunk *chunk = arg;
2119 if (!sctp_vtag_verify_either(chunk, asoc))
2120 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2122 /* Make sure that the ABORT chunk has a valid length.
2123 * Since this is an ABORT chunk, we have to discard it
2124 * because of the following text:
2125 * RFC 2960, Section 3.3.7
2126 * If an endpoint receives an ABORT with a format error or for an
2127 * association that doesn't exist, it MUST silently discard it.
2128 * Because the length is "invalid", we can't really discard just
2129 * as we do not know its true length. So, to be safe, discard the
2132 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2133 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2135 /* ADD-IP: Special case for ABORT chunks
2136 * F4) One special consideration is that ABORT Chunks arriving
2137 * destined to the IP address being deleted MUST be
2138 * ignored (see Section 5.3.1 for further details).
2140 if (SCTP_ADDR_DEL ==
2141 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2142 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2144 /* Stop the T2-shutdown timer. */
2145 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2146 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2148 /* Stop the T5-shutdown guard timer. */
2149 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2150 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2152 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2156 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2158 * See sctp_sf_do_9_1_abort().
2160 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2161 const struct sctp_endpoint *ep,
2162 const struct sctp_association *asoc,
2163 const sctp_subtype_t type,
2165 sctp_cmd_seq_t *commands)
2167 /* The same T2 timer, so we should be able to use
2168 * common function with the SHUTDOWN-SENT state.
2170 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2174 * Handle an Error received in COOKIE_ECHOED state.
2176 * Only handle the error type of stale COOKIE Error, the other errors will
2180 * (endpoint, asoc, chunk)
2183 * (asoc, reply_msg, msg_up, timers, counters)
2185 * The return value is the disposition of the chunk.
2187 sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2188 const struct sctp_association *asoc,
2189 const sctp_subtype_t type,
2191 sctp_cmd_seq_t *commands)
2193 struct sctp_chunk *chunk = arg;
2196 if (!sctp_vtag_verify(chunk, asoc))
2197 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2199 /* Make sure that the ERROR chunk has a valid length.
2200 * The parameter walking depends on this as well.
2202 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2203 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2206 /* Process the error here */
2207 /* FUTURE FIXME: When PR-SCTP related and other optional
2208 * parms are emitted, this will have to change to handle multiple
2211 sctp_walk_errors(err, chunk->chunk_hdr) {
2212 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2213 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2217 /* It is possible to have malformed error causes, and that
2218 * will cause us to end the walk early. However, since
2219 * we are discarding the packet, there should be no adverse
2222 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2226 * Handle a Stale COOKIE Error
2228 * Section: 5.2.6 Handle Stale COOKIE Error
2229 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2230 * one of the following three alternatives.
2232 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2233 * Preservative parameter requesting an extension to the lifetime of
2234 * the State Cookie. When calculating the time extension, an
2235 * implementation SHOULD use the RTT information measured based on the
2236 * previous COOKIE ECHO / ERROR exchange, and should add no more
2237 * than 1 second beyond the measured RTT, due to long State Cookie
2238 * lifetimes making the endpoint more subject to a replay attack.
2240 * Verification Tag: Not explicit, but safe to ignore.
2243 * (endpoint, asoc, chunk)
2246 * (asoc, reply_msg, msg_up, timers, counters)
2248 * The return value is the disposition of the chunk.
2250 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2251 const struct sctp_association *asoc,
2252 const sctp_subtype_t type,
2254 sctp_cmd_seq_t *commands)
2256 struct sctp_chunk *chunk = arg;
2258 sctp_cookie_preserve_param_t bht;
2260 struct sctp_chunk *reply;
2261 struct sctp_bind_addr *bp;
2262 int attempts = asoc->init_err_counter + 1;
2264 if (attempts > asoc->max_init_attempts) {
2265 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2266 SCTP_ERROR(ETIMEDOUT));
2267 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2268 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2269 return SCTP_DISPOSITION_DELETE_TCB;
2272 err = (sctp_errhdr_t *)(chunk->skb->data);
2274 /* When calculating the time extension, an implementation
2275 * SHOULD use the RTT information measured based on the
2276 * previous COOKIE ECHO / ERROR exchange, and should add no
2277 * more than 1 second beyond the measured RTT, due to long
2278 * State Cookie lifetimes making the endpoint more subject to
2280 * Measure of Staleness's unit is usec. (1/1000000 sec)
2281 * Suggested Cookie Life-span Increment's unit is msec.
2283 * In general, if you use the suggested cookie life, the value
2284 * found in the field of measure of staleness should be doubled
2285 * to give ample time to retransmit the new cookie and thus
2286 * yield a higher probability of success on the reattempt.
2288 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2289 stale = (stale * 2) / 1000;
2291 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2292 bht.param_hdr.length = htons(sizeof(bht));
2293 bht.lifespan_increment = htonl(stale);
2295 /* Build that new INIT chunk. */
2296 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2297 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2301 sctp_addto_chunk(reply, sizeof(bht), &bht);
2303 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2304 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2306 /* Stop pending T3-rtx and heartbeat timers */
2307 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2308 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2310 /* Delete non-primary peer ip addresses since we are transitioning
2311 * back to the COOKIE-WAIT state
2313 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2315 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2318 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2319 SCTP_TRANSPORT(asoc->peer.primary_path));
2321 /* Cast away the const modifier, as we want to just
2322 * rerun it through as a sideffect.
2324 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2326 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2327 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2328 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2329 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2330 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2331 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2333 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2335 return SCTP_DISPOSITION_CONSUME;
2338 return SCTP_DISPOSITION_NOMEM;
2345 * After checking the Verification Tag, the receiving endpoint shall
2346 * remove the association from its record, and shall report the
2347 * termination to its upper layer.
2349 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2350 * B) Rules for packet carrying ABORT:
2352 * - The endpoint shall always fill in the Verification Tag field of the
2353 * outbound packet with the destination endpoint's tag value if it
2356 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2357 * MUST follow the procedure described in Section 8.4.
2359 * - The receiver MUST accept the packet if the Verification Tag
2360 * matches either its own tag, OR the tag of its peer. Otherwise, the
2361 * receiver MUST silently discard the packet and take no further
2365 * (endpoint, asoc, chunk)
2368 * (asoc, reply_msg, msg_up, timers, counters)
2370 * The return value is the disposition of the chunk.
2372 sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2373 const struct sctp_association *asoc,
2374 const sctp_subtype_t type,
2376 sctp_cmd_seq_t *commands)
2378 struct sctp_chunk *chunk = arg;
2380 if (!sctp_vtag_verify_either(chunk, asoc))
2381 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2383 /* Make sure that the ABORT chunk has a valid length.
2384 * Since this is an ABORT chunk, we have to discard it
2385 * because of the following text:
2386 * RFC 2960, Section 3.3.7
2387 * If an endpoint receives an ABORT with a format error or for an
2388 * association that doesn't exist, it MUST silently discard it.
2389 * Because the length is "invalid", we can't really discard just
2390 * as we do not know its true length. So, to be safe, discard the
2393 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2394 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2396 /* ADD-IP: Special case for ABORT chunks
2397 * F4) One special consideration is that ABORT Chunks arriving
2398 * destined to the IP address being deleted MUST be
2399 * ignored (see Section 5.3.1 for further details).
2401 if (SCTP_ADDR_DEL ==
2402 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2403 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2405 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2408 static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2409 const struct sctp_association *asoc,
2410 const sctp_subtype_t type,
2412 sctp_cmd_seq_t *commands)
2414 struct sctp_chunk *chunk = arg;
2416 __be16 error = SCTP_ERROR_NO_ERROR;
2418 /* See if we have an error cause code in the chunk. */
2419 len = ntohs(chunk->chunk_hdr->length);
2420 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2423 sctp_walk_errors(err, chunk->chunk_hdr);
2424 if ((void *)err != (void *)chunk->chunk_end)
2425 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2427 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2430 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2431 /* ASSOC_FAILED will DELETE_TCB. */
2432 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2433 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2434 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2436 return SCTP_DISPOSITION_ABORT;
2440 * Process an ABORT. (COOKIE-WAIT state)
2442 * See sctp_sf_do_9_1_abort() above.
2444 sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2445 const struct sctp_association *asoc,
2446 const sctp_subtype_t type,
2448 sctp_cmd_seq_t *commands)
2450 struct sctp_chunk *chunk = arg;
2452 __be16 error = SCTP_ERROR_NO_ERROR;
2454 if (!sctp_vtag_verify_either(chunk, asoc))
2455 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2457 /* Make sure that the ABORT chunk has a valid length.
2458 * Since this is an ABORT chunk, we have to discard it
2459 * because of the following text:
2460 * RFC 2960, Section 3.3.7
2461 * If an endpoint receives an ABORT with a format error or for an
2462 * association that doesn't exist, it MUST silently discard it.
2463 * Because the length is "invalid", we can't really discard just
2464 * as we do not know its true length. So, to be safe, discard the
2467 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2468 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2470 /* See if we have an error cause code in the chunk. */
2471 len = ntohs(chunk->chunk_hdr->length);
2472 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2473 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2475 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2480 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2482 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2483 const struct sctp_association *asoc,
2484 const sctp_subtype_t type,
2486 sctp_cmd_seq_t *commands)
2488 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2490 (struct sctp_transport *)arg);
2494 * Process an ABORT. (COOKIE-ECHOED state)
2496 sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2497 const struct sctp_association *asoc,
2498 const sctp_subtype_t type,
2500 sctp_cmd_seq_t *commands)
2502 /* There is a single T1 timer, so we should be able to use
2503 * common function with the COOKIE-WAIT state.
2505 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2509 * Stop T1 timer and abort association with "INIT failed".
2511 * This is common code called by several sctp_sf_*_abort() functions above.
2513 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
2514 __be16 error, int sk_err,
2515 const struct sctp_association *asoc,
2516 struct sctp_transport *transport)
2518 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2519 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2520 SCTP_STATE(SCTP_STATE_CLOSED));
2521 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2522 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2523 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2524 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2525 /* CMD_INIT_FAILED will DELETE_TCB. */
2526 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2528 return SCTP_DISPOSITION_ABORT;
2532 * sctp_sf_do_9_2_shut
2535 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2536 * - enter the SHUTDOWN-RECEIVED state,
2538 * - stop accepting new data from its SCTP user
2540 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2541 * that all its outstanding DATA chunks have been received by the
2544 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2545 * send a SHUTDOWN in response to a ULP request. And should discard
2546 * subsequent SHUTDOWN chunks.
2548 * If there are still outstanding DATA chunks left, the SHUTDOWN
2549 * receiver shall continue to follow normal data transmission
2550 * procedures defined in Section 6 until all outstanding DATA chunks
2551 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2552 * new data from its SCTP user.
2554 * Verification Tag: 8.5 Verification Tag [Normal verification]
2557 * (endpoint, asoc, chunk)
2560 * (asoc, reply_msg, msg_up, timers, counters)
2562 * The return value is the disposition of the chunk.
2564 sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2565 const struct sctp_association *asoc,
2566 const sctp_subtype_t type,
2568 sctp_cmd_seq_t *commands)
2570 struct sctp_chunk *chunk = arg;
2571 sctp_shutdownhdr_t *sdh;
2572 sctp_disposition_t disposition;
2573 struct sctp_ulpevent *ev;
2576 if (!sctp_vtag_verify(chunk, asoc))
2577 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2579 /* Make sure that the SHUTDOWN chunk has a valid length. */
2580 if (!sctp_chunk_length_valid(chunk,
2581 sizeof(struct sctp_shutdown_chunk_t)))
2582 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2585 /* Convert the elaborate header. */
2586 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2587 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2588 chunk->subh.shutdown_hdr = sdh;
2589 ctsn = ntohl(sdh->cum_tsn_ack);
2591 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2592 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2593 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2594 return SCTP_DISPOSITION_DISCARD;
2597 /* If Cumulative TSN Ack beyond the max tsn currently
2598 * send, terminating the association and respond to the
2599 * sender with an ABORT.
2601 if (!TSN_lt(ctsn, asoc->next_tsn))
2602 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2604 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2605 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2606 * inform the application that it should cease sending data.
2608 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2610 disposition = SCTP_DISPOSITION_NOMEM;
2613 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2615 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2616 * - enter the SHUTDOWN-RECEIVED state,
2617 * - stop accepting new data from its SCTP user
2619 * [This is implicit in the new state.]
2621 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2622 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2623 disposition = SCTP_DISPOSITION_CONSUME;
2625 if (sctp_outq_is_empty(&asoc->outqueue)) {
2626 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2630 if (SCTP_DISPOSITION_NOMEM == disposition)
2633 /* - verify, by checking the Cumulative TSN Ack field of the
2634 * chunk, that all its outstanding DATA chunks have been
2635 * received by the SHUTDOWN sender.
2637 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2638 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2645 * sctp_sf_do_9_2_shut_ctsn
2647 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2648 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2649 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2650 * MUST be processed.
2652 sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
2653 const struct sctp_association *asoc,
2654 const sctp_subtype_t type,
2656 sctp_cmd_seq_t *commands)
2658 struct sctp_chunk *chunk = arg;
2659 sctp_shutdownhdr_t *sdh;
2662 if (!sctp_vtag_verify(chunk, asoc))
2663 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2665 /* Make sure that the SHUTDOWN chunk has a valid length. */
2666 if (!sctp_chunk_length_valid(chunk,
2667 sizeof(struct sctp_shutdown_chunk_t)))
2668 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2671 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2672 ctsn = ntohl(sdh->cum_tsn_ack);
2674 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2675 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2676 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2677 return SCTP_DISPOSITION_DISCARD;
2680 /* If Cumulative TSN Ack beyond the max tsn currently
2681 * send, terminating the association and respond to the
2682 * sender with an ABORT.
2684 if (!TSN_lt(ctsn, asoc->next_tsn))
2685 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2687 /* verify, by checking the Cumulative TSN Ack field of the
2688 * chunk, that all its outstanding DATA chunks have been
2689 * received by the SHUTDOWN sender.
2691 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2692 SCTP_BE32(sdh->cum_tsn_ack));
2694 return SCTP_DISPOSITION_CONSUME;
2698 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2699 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2700 * transport addresses (either in the IP addresses or in the INIT chunk)
2701 * that belong to this association, it should discard the INIT chunk and
2702 * retransmit the SHUTDOWN ACK chunk.
2704 sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2705 const struct sctp_association *asoc,
2706 const sctp_subtype_t type,
2708 sctp_cmd_seq_t *commands)
2710 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2711 struct sctp_chunk *reply;
2713 /* Make sure that the chunk has a valid length */
2714 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2715 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2718 /* Since we are not going to really process this INIT, there
2719 * is no point in verifying chunk boundries. Just generate
2722 reply = sctp_make_shutdown_ack(asoc, chunk);
2726 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2727 * the T2-SHUTDOWN timer.
2729 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2731 /* and restart the T2-shutdown timer. */
2732 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2733 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2735 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2737 return SCTP_DISPOSITION_CONSUME;
2739 return SCTP_DISPOSITION_NOMEM;
2743 * sctp_sf_do_ecn_cwr
2745 * Section: Appendix A: Explicit Congestion Notification
2749 * RFC 2481 details a specific bit for a sender to send in the header of
2750 * its next outbound TCP segment to indicate to its peer that it has
2751 * reduced its congestion window. This is termed the CWR bit. For
2752 * SCTP the same indication is made by including the CWR chunk.
2753 * This chunk contains one data element, i.e. the TSN number that
2754 * was sent in the ECNE chunk. This element represents the lowest
2755 * TSN number in the datagram that was originally marked with the
2758 * Verification Tag: 8.5 Verification Tag [Normal verification]
2760 * (endpoint, asoc, chunk)
2763 * (asoc, reply_msg, msg_up, timers, counters)
2765 * The return value is the disposition of the chunk.
2767 sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2768 const struct sctp_association *asoc,
2769 const sctp_subtype_t type,
2771 sctp_cmd_seq_t *commands)
2774 struct sctp_chunk *chunk = arg;
2777 if (!sctp_vtag_verify(chunk, asoc))
2778 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2780 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2781 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2784 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2785 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2787 lowest_tsn = ntohl(cwr->lowest_tsn);
2789 /* Does this CWR ack the last sent congestion notification? */
2790 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2791 /* Stop sending ECNE. */
2792 sctp_add_cmd_sf(commands,
2794 SCTP_U32(lowest_tsn));
2796 return SCTP_DISPOSITION_CONSUME;
2802 * Section: Appendix A: Explicit Congestion Notification
2806 * RFC 2481 details a specific bit for a receiver to send back in its
2807 * TCP acknowledgements to notify the sender of the Congestion
2808 * Experienced (CE) bit having arrived from the network. For SCTP this
2809 * same indication is made by including the ECNE chunk. This chunk
2810 * contains one data element, i.e. the lowest TSN associated with the IP
2811 * datagram marked with the CE bit.....
2813 * Verification Tag: 8.5 Verification Tag [Normal verification]
2815 * (endpoint, asoc, chunk)
2818 * (asoc, reply_msg, msg_up, timers, counters)
2820 * The return value is the disposition of the chunk.
2822 sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2823 const struct sctp_association *asoc,
2824 const sctp_subtype_t type,
2826 sctp_cmd_seq_t *commands)
2828 sctp_ecnehdr_t *ecne;
2829 struct sctp_chunk *chunk = arg;
2831 if (!sctp_vtag_verify(chunk, asoc))
2832 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2834 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2835 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2838 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2839 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2841 /* If this is a newer ECNE than the last CWR packet we sent out */
2842 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2843 SCTP_U32(ntohl(ecne->lowest_tsn)));
2845 return SCTP_DISPOSITION_CONSUME;
2849 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2851 * The SCTP endpoint MUST always acknowledge the reception of each valid
2854 * The guidelines on delayed acknowledgement algorithm specified in
2855 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2856 * acknowledgement SHOULD be generated for at least every second packet
2857 * (not every second DATA chunk) received, and SHOULD be generated within
2858 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2859 * situations it may be beneficial for an SCTP transmitter to be more
2860 * conservative than the algorithms detailed in this document allow.
2861 * However, an SCTP transmitter MUST NOT be more aggressive than the
2862 * following algorithms allow.
2864 * A SCTP receiver MUST NOT generate more than one SACK for every
2865 * incoming packet, other than to update the offered window as the
2866 * receiving application consumes new data.
2868 * Verification Tag: 8.5 Verification Tag [Normal verification]
2871 * (endpoint, asoc, chunk)
2874 * (asoc, reply_msg, msg_up, timers, counters)
2876 * The return value is the disposition of the chunk.
2878 sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2879 const struct sctp_association *asoc,
2880 const sctp_subtype_t type,
2882 sctp_cmd_seq_t *commands)
2884 struct sctp_chunk *chunk = arg;
2885 sctp_arg_t force = SCTP_NOFORCE();
2888 if (!sctp_vtag_verify(chunk, asoc)) {
2889 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2891 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2894 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2895 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2898 error = sctp_eat_data(asoc, chunk, commands );
2900 case SCTP_IERROR_NO_ERROR:
2902 case SCTP_IERROR_HIGH_TSN:
2903 case SCTP_IERROR_BAD_STREAM:
2904 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2905 goto discard_noforce;
2906 case SCTP_IERROR_DUP_TSN:
2907 case SCTP_IERROR_IGNORE_TSN:
2908 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2910 case SCTP_IERROR_NO_DATA:
2912 case SCTP_IERROR_PROTO_VIOLATION:
2913 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
2914 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
2919 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2920 force = SCTP_FORCE();
2922 if (asoc->autoclose) {
2923 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2924 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2927 /* If this is the last chunk in a packet, we need to count it
2928 * toward sack generation. Note that we need to SACK every
2929 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2930 * THEM. We elect to NOT generate SACK's if the chunk fails
2931 * the verification tag test.
2933 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2935 * The SCTP endpoint MUST always acknowledge the reception of
2936 * each valid DATA chunk.
2938 * The guidelines on delayed acknowledgement algorithm
2939 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2940 * Specifically, an acknowledgement SHOULD be generated for at
2941 * least every second packet (not every second DATA chunk)
2942 * received, and SHOULD be generated within 200 ms of the
2943 * arrival of any unacknowledged DATA chunk. In some
2944 * situations it may be beneficial for an SCTP transmitter to
2945 * be more conservative than the algorithms detailed in this
2946 * document allow. However, an SCTP transmitter MUST NOT be
2947 * more aggressive than the following algorithms allow.
2949 if (chunk->end_of_packet)
2950 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
2952 return SCTP_DISPOSITION_CONSUME;
2955 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2957 * When a packet arrives with duplicate DATA chunk(s) and with
2958 * no new DATA chunk(s), the endpoint MUST immediately send a
2959 * SACK with no delay. If a packet arrives with duplicate
2960 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2961 * MAY immediately send a SACK. Normally receipt of duplicate
2962 * DATA chunks will occur when the original SACK chunk was lost
2963 * and the peer's RTO has expired. The duplicate TSN number(s)
2964 * SHOULD be reported in the SACK as duplicate.
2966 /* In our case, we split the MAY SACK advice up whether or not
2967 * the last chunk is a duplicate.'
2969 if (chunk->end_of_packet)
2970 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2971 return SCTP_DISPOSITION_DISCARD;
2974 if (chunk->end_of_packet)
2975 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
2977 return SCTP_DISPOSITION_DISCARD;
2979 return SCTP_DISPOSITION_CONSUME;
2984 * sctp_sf_eat_data_fast_4_4
2987 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2988 * DATA chunks without delay.
2990 * Verification Tag: 8.5 Verification Tag [Normal verification]
2992 * (endpoint, asoc, chunk)
2995 * (asoc, reply_msg, msg_up, timers, counters)
2997 * The return value is the disposition of the chunk.
2999 sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
3000 const struct sctp_association *asoc,
3001 const sctp_subtype_t type,
3003 sctp_cmd_seq_t *commands)
3005 struct sctp_chunk *chunk = arg;
3008 if (!sctp_vtag_verify(chunk, asoc)) {
3009 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3011 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3014 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3015 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3018 error = sctp_eat_data(asoc, chunk, commands );
3020 case SCTP_IERROR_NO_ERROR:
3021 case SCTP_IERROR_HIGH_TSN:
3022 case SCTP_IERROR_DUP_TSN:
3023 case SCTP_IERROR_IGNORE_TSN:
3024 case SCTP_IERROR_BAD_STREAM:
3026 case SCTP_IERROR_NO_DATA:
3028 case SCTP_IERROR_PROTO_VIOLATION:
3029 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
3030 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3035 /* Go a head and force a SACK, since we are shutting down. */
3037 /* Implementor's Guide.
3039 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3040 * respond to each received packet containing one or more DATA chunk(s)
3041 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3043 if (chunk->end_of_packet) {
3044 /* We must delay the chunk creation since the cumulative
3045 * TSN has not been updated yet.
3047 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3048 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3049 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3050 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3054 return SCTP_DISPOSITION_CONSUME;
3058 * Section: 6.2 Processing a Received SACK
3059 * D) Any time a SACK arrives, the endpoint performs the following:
3061 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3062 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3063 * increasing, a SACK whose Cumulative TSN Ack is less than the
3064 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3066 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3067 * of bytes still outstanding after processing the Cumulative TSN Ack
3068 * and the Gap Ack Blocks.
3070 * iii) If the SACK is missing a TSN that was previously
3071 * acknowledged via a Gap Ack Block (e.g., the data receiver
3072 * reneged on the data), then mark the corresponding DATA chunk
3073 * as available for retransmit: Mark it as missing for fast
3074 * retransmit as described in Section 7.2.4 and if no retransmit
3075 * timer is running for the destination address to which the DATA
3076 * chunk was originally transmitted, then T3-rtx is started for
3077 * that destination address.
3079 * Verification Tag: 8.5 Verification Tag [Normal verification]
3082 * (endpoint, asoc, chunk)
3085 * (asoc, reply_msg, msg_up, timers, counters)
3087 * The return value is the disposition of the chunk.
3089 sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
3090 const struct sctp_association *asoc,
3091 const sctp_subtype_t type,
3093 sctp_cmd_seq_t *commands)
3095 struct sctp_chunk *chunk = arg;
3096 sctp_sackhdr_t *sackh;
3099 if (!sctp_vtag_verify(chunk, asoc))
3100 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3102 /* Make sure that the SACK chunk has a valid length. */
3103 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3104 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3107 /* Pull the SACK chunk from the data buffer */
3108 sackh = sctp_sm_pull_sack(chunk);
3109 /* Was this a bogus SACK? */
3111 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3112 chunk->subh.sack_hdr = sackh;
3113 ctsn = ntohl(sackh->cum_tsn_ack);
3115 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3116 * Ack Point, then drop the SACK. Since Cumulative TSN
3117 * Ack is monotonically increasing, a SACK whose
3118 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3119 * Point indicates an out-of-order SACK.
3121 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3122 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3123 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3124 return SCTP_DISPOSITION_DISCARD;
3127 /* If Cumulative TSN Ack beyond the max tsn currently
3128 * send, terminating the association and respond to the
3129 * sender with an ABORT.
3131 if (!TSN_lt(ctsn, asoc->next_tsn))
3132 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3134 /* Return this SACK for further processing. */
3135 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3137 /* Note: We do the rest of the work on the PROCESS_SACK
3140 return SCTP_DISPOSITION_CONSUME;
3144 * Generate an ABORT in response to a packet.
3146 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3148 * 8) The receiver should respond to the sender of the OOTB packet with
3149 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3150 * MUST fill in the Verification Tag field of the outbound packet
3151 * with the value found in the Verification Tag field of the OOTB
3152 * packet and set the T-bit in the Chunk Flags to indicate that the
3153 * Verification Tag is reflected. After sending this ABORT, the
3154 * receiver of the OOTB packet shall discard the OOTB packet and take
3155 * no further action.
3159 * The return value is the disposition of the chunk.
3161 static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
3162 const struct sctp_association *asoc,
3163 const sctp_subtype_t type,
3165 sctp_cmd_seq_t *commands)
3167 struct sctp_packet *packet = NULL;
3168 struct sctp_chunk *chunk = arg;
3169 struct sctp_chunk *abort;
3171 packet = sctp_ootb_pkt_new(asoc, chunk);
3174 /* Make an ABORT. The T bit will be set if the asoc
3177 abort = sctp_make_abort(asoc, chunk, 0);
3179 sctp_ootb_pkt_free(packet);
3180 return SCTP_DISPOSITION_NOMEM;
3183 /* Reflect vtag if T-Bit is set */
3184 if (sctp_test_T_bit(abort))
3185 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3187 /* Set the skb to the belonging sock for accounting. */
3188 abort->skb->sk = ep->base.sk;
3190 sctp_packet_append_chunk(packet, abort);
3192 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3193 SCTP_PACKET(packet));
3195 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3197 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3198 return SCTP_DISPOSITION_CONSUME;
3201 return SCTP_DISPOSITION_NOMEM;
3205 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3206 * event as ULP notification for each cause included in the chunk.
3208 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3210 * The return value is the disposition of the chunk.
3212 sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3213 const struct sctp_association *asoc,
3214 const sctp_subtype_t type,
3216 sctp_cmd_seq_t *commands)
3218 struct sctp_chunk *chunk = arg;
3221 if (!sctp_vtag_verify(chunk, asoc))
3222 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3224 /* Make sure that the ERROR chunk has a valid length. */
3225 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3226 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3228 sctp_walk_errors(err, chunk->chunk_hdr);
3229 if ((void *)err != (void *)chunk->chunk_end)
3230 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3231 (void *)err, commands);
3233 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3236 return SCTP_DISPOSITION_CONSUME;
3240 * Process an inbound SHUTDOWN ACK.
3243 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3244 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3245 * peer, and remove all record of the association.
3247 * The return value is the disposition.
3249 sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3250 const struct sctp_association *asoc,
3251 const sctp_subtype_t type,
3253 sctp_cmd_seq_t *commands)
3255 struct sctp_chunk *chunk = arg;
3256 struct sctp_chunk *reply;
3257 struct sctp_ulpevent *ev;
3259 if (!sctp_vtag_verify(chunk, asoc))
3260 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3262 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3263 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3264 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3266 /* 10.2 H) SHUTDOWN COMPLETE notification
3268 * When SCTP completes the shutdown procedures (section 9.2) this
3269 * notification is passed to the upper layer.
3271 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3272 0, 0, 0, NULL, GFP_ATOMIC);
3276 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3277 reply = sctp_make_shutdown_complete(asoc, chunk);
3281 /* Do all the commands now (after allocation), so that we
3282 * have consistent state if memory allocation failes
3284 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3286 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3287 * stop the T2-shutdown timer,
3289 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3290 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3292 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3293 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3295 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3296 SCTP_STATE(SCTP_STATE_CLOSED));
3297 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3298 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3299 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3301 /* ...and remove all record of the association. */
3302 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3303 return SCTP_DISPOSITION_DELETE_TCB;
3306 sctp_ulpevent_free(ev);
3308 return SCTP_DISPOSITION_NOMEM;
3312 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3314 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3315 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3316 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3317 * packet must fill in the Verification Tag field of the outbound
3318 * packet with the Verification Tag received in the SHUTDOWN ACK and
3319 * set the T-bit in the Chunk Flags to indicate that the Verification
3322 * 8) The receiver should respond to the sender of the OOTB packet with
3323 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3324 * MUST fill in the Verification Tag field of the outbound packet
3325 * with the value found in the Verification Tag field of the OOTB
3326 * packet and set the T-bit in the Chunk Flags to indicate that the
3327 * Verification Tag is reflected. After sending this ABORT, the
3328 * receiver of the OOTB packet shall discard the OOTB packet and take
3329 * no further action.
3331 sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3332 const struct sctp_association *asoc,
3333 const sctp_subtype_t type,
3335 sctp_cmd_seq_t *commands)
3337 struct sctp_chunk *chunk = arg;
3338 struct sk_buff *skb = chunk->skb;
3339 sctp_chunkhdr_t *ch;
3342 int ootb_shut_ack = 0;
3343 int ootb_cookie_ack = 0;
3345 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3347 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3349 /* Report violation if the chunk is less then minimal */
3350 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3351 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3354 /* Now that we know we at least have a chunk header,
3355 * do things that are type appropriate.
3357 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3360 /* RFC 2960, Section 3.3.7
3361 * Moreover, under any circumstances, an endpoint that
3362 * receives an ABORT MUST NOT respond to that ABORT by
3363 * sending an ABORT of its own.
3365 if (SCTP_CID_ABORT == ch->type)
3366 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3368 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3369 * or a COOKIE ACK the SCTP Packet should be silently
3373 if (SCTP_CID_COOKIE_ACK == ch->type)
3374 ootb_cookie_ack = 1;
3376 if (SCTP_CID_ERROR == ch->type) {
3377 sctp_walk_errors(err, ch) {
3378 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3379 ootb_cookie_ack = 1;
3385 /* Report violation if chunk len overflows */
3386 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3387 if (ch_end > skb_tail_pointer(skb))
3388 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3391 ch = (sctp_chunkhdr_t *) ch_end;
3392 } while (ch_end < skb_tail_pointer(skb));
3395 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3396 else if (ootb_cookie_ack)
3397 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3399 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3403 * Handle an "Out of the blue" SHUTDOWN ACK.
3405 * Section: 8.4 5, sctpimpguide 2.41.
3407 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3408 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3409 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3410 * packet must fill in the Verification Tag field of the outbound
3411 * packet with the Verification Tag received in the SHUTDOWN ACK and
3412 * set the T-bit in the Chunk Flags to indicate that the Verification
3416 * (endpoint, asoc, type, arg, commands)
3419 * (sctp_disposition_t)
3421 * The return value is the disposition of the chunk.
3423 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3424 const struct sctp_association *asoc,
3425 const sctp_subtype_t type,
3427 sctp_cmd_seq_t *commands)
3429 struct sctp_packet *packet = NULL;
3430 struct sctp_chunk *chunk = arg;
3431 struct sctp_chunk *shut;
3433 packet = sctp_ootb_pkt_new(asoc, chunk);
3436 /* Make an SHUTDOWN_COMPLETE.
3437 * The T bit will be set if the asoc is NULL.
3439 shut = sctp_make_shutdown_complete(asoc, chunk);
3441 sctp_ootb_pkt_free(packet);
3442 return SCTP_DISPOSITION_NOMEM;
3445 /* Reflect vtag if T-Bit is set */
3446 if (sctp_test_T_bit(shut))
3447 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3449 /* Set the skb to the belonging sock for accounting. */
3450 shut->skb->sk = ep->base.sk;
3452 sctp_packet_append_chunk(packet, shut);
3454 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3455 SCTP_PACKET(packet));
3457 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3459 /* If the chunk length is invalid, we don't want to process
3460 * the reset of the packet.
3462 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3463 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3465 /* We need to discard the rest of the packet to prevent
3466 * potential bomming attacks from additional bundled chunks.
3467 * This is documented in SCTP Threats ID.
3469 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3472 return SCTP_DISPOSITION_NOMEM;
3476 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3478 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3479 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3480 * procedures in section 8.4 SHOULD be followed, in other words it
3481 * should be treated as an Out Of The Blue packet.
3482 * [This means that we do NOT check the Verification Tag on these
3486 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3487 const struct sctp_association *asoc,
3488 const sctp_subtype_t type,
3490 sctp_cmd_seq_t *commands)
3492 struct sctp_chunk *chunk = arg;
3494 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3495 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3496 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3499 /* Although we do have an association in this case, it corresponds
3500 * to a restarted association. So the packet is treated as an OOTB
3501 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3502 * called with a NULL association.
3504 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3506 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3509 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3510 sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3511 const struct sctp_association *asoc,
3512 const sctp_subtype_t type, void *arg,
3513 sctp_cmd_seq_t *commands)
3515 struct sctp_chunk *chunk = arg;
3516 struct sctp_chunk *asconf_ack = NULL;
3517 struct sctp_paramhdr *err_param = NULL;
3518 sctp_addiphdr_t *hdr;
3521 if (!sctp_vtag_verify(chunk, asoc)) {
3522 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3524 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3527 /* ADD-IP: Section 4.1.1
3528 * This chunk MUST be sent in an authenticated way by using
3529 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3530 * is received unauthenticated it MUST be silently discarded as
3531 * described in [I-D.ietf-tsvwg-sctp-auth].
3533 if (!sctp_addip_noauth && !chunk->auth)
3534 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3536 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3537 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3538 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3541 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3542 serial = ntohl(hdr->serial);
3544 /* Verify the ASCONF chunk before processing it. */
3545 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
3546 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3547 (void *)err_param, commands);
3549 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3550 * the endpoint stored in a new association variable
3551 * 'Peer-Serial-Number'.
3553 if (serial == asoc->peer.addip_serial + 1) {
3554 /* If this is the first instance of ASCONF in the packet,
3555 * we can clean our old ASCONF-ACKs.
3557 if (!chunk->has_asconf)
3558 sctp_assoc_clean_asconf_ack_cache(asoc);
3560 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3561 * expected, process the ASCONF as described below and after
3562 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3563 * the response packet and cache a copy of it (in the event it
3564 * later needs to be retransmitted).
3566 * Essentially, do V1-V5.
3568 asconf_ack = sctp_process_asconf((struct sctp_association *)
3571 return SCTP_DISPOSITION_NOMEM;
3572 } else if (serial < asoc->peer.addip_serial + 1) {
3574 * If the value found in the Sequence Number is less than the
3575 * ('Peer- Sequence-Number' + 1), simply skip to the next
3576 * ASCONF, and include in the outbound response packet
3577 * any previously cached ASCONF-ACK response that was
3578 * sent and saved that matches the Sequence Number of the
3579 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3580 * Chunk exists. This will occur when an older ASCONF
3581 * arrives out of order. In such a case, the receiver
3582 * should skip the ASCONF Chunk and not include ASCONF-ACK
3583 * Chunk for that chunk.
3585 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3587 return SCTP_DISPOSITION_DISCARD;
3589 /* Reset the transport so that we select the correct one
3590 * this time around. This is to make sure that we don't
3591 * accidentally use a stale transport that's been removed.
3593 asconf_ack->transport = NULL;
3595 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3596 * it must be either a stale packet or from an attacker.
3598 return SCTP_DISPOSITION_DISCARD;
3601 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3602 * containing the ASCONF-ACK Chunks MUST be the source address of
3603 * the SCTP packet that held the ASCONF Chunks.
3605 * To do this properly, we'll set the destination address of the chunk
3606 * and at the transmit time, will try look up the transport to use.
3607 * Since ASCONFs may be bundled, the correct transport may not be
3608 * created until we process the entire packet, thus this workaround.
3610 asconf_ack->dest = chunk->source;
3611 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3612 if (asoc->new_transport) {
3613 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport,
3615 ((struct sctp_association *)asoc)->new_transport = NULL;
3618 return SCTP_DISPOSITION_CONSUME;
3622 * ADDIP Section 4.3 General rules for address manipulation
3623 * When building TLV parameters for the ASCONF Chunk that will add or
3624 * delete IP addresses the D0 to D13 rules should be applied:
3626 sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3627 const struct sctp_association *asoc,
3628 const sctp_subtype_t type, void *arg,
3629 sctp_cmd_seq_t *commands)
3631 struct sctp_chunk *asconf_ack = arg;
3632 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3633 struct sctp_chunk *abort;
3634 struct sctp_paramhdr *err_param = NULL;
3635 sctp_addiphdr_t *addip_hdr;
3636 __u32 sent_serial, rcvd_serial;
3638 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3639 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3641 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3644 /* ADD-IP, Section 4.1.2:
3645 * This chunk MUST be sent in an authenticated way by using
3646 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3647 * is received unauthenticated it MUST be silently discarded as
3648 * described in [I-D.ietf-tsvwg-sctp-auth].
3650 if (!sctp_addip_noauth && !asconf_ack->auth)
3651 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3653 /* Make sure that the ADDIP chunk has a valid length. */
3654 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3655 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3658 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3659 rcvd_serial = ntohl(addip_hdr->serial);
3661 /* Verify the ASCONF-ACK chunk before processing it. */
3662 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
3663 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3664 (void *)err_param, commands);
3667 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3668 sent_serial = ntohl(addip_hdr->serial);
3670 sent_serial = asoc->addip_serial - 1;
3673 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3674 * equal to the next serial number to be used but no ASCONF chunk is
3675 * outstanding the endpoint MUST ABORT the association. Note that a
3676 * sequence number is greater than if it is no more than 2^^31-1
3677 * larger than the current sequence number (using serial arithmetic).
3679 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3680 !(asoc->addip_last_asconf)) {
3681 abort = sctp_make_abort(asoc, asconf_ack,
3682 sizeof(sctp_errhdr_t));
3684 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3685 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3688 /* We are going to ABORT, so we might as well stop
3689 * processing the rest of the chunks in the packet.
3691 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3692 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3693 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3694 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3695 SCTP_ERROR(ECONNABORTED));
3696 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3697 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3698 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3699 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3700 return SCTP_DISPOSITION_ABORT;
3703 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3704 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3705 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3707 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3709 /* Successfully processed ASCONF_ACK. We can
3710 * release the next asconf if we have one.
3712 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3714 return SCTP_DISPOSITION_CONSUME;
3717 abort = sctp_make_abort(asoc, asconf_ack,
3718 sizeof(sctp_errhdr_t));
3720 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3721 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3724 /* We are going to ABORT, so we might as well stop
3725 * processing the rest of the chunks in the packet.
3727 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3728 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3729 SCTP_ERROR(ECONNABORTED));
3730 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3731 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3732 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3733 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3734 return SCTP_DISPOSITION_ABORT;
3737 return SCTP_DISPOSITION_DISCARD;
3741 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3743 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3744 * its cumulative TSN point to the value carried in the FORWARD TSN
3745 * chunk, and then MUST further advance its cumulative TSN point locally
3747 * After the above processing, the data receiver MUST stop reporting any
3748 * missing TSNs earlier than or equal to the new cumulative TSN point.
3750 * Verification Tag: 8.5 Verification Tag [Normal verification]
3752 * The return value is the disposition of the chunk.
3754 sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3755 const struct sctp_association *asoc,
3756 const sctp_subtype_t type,
3758 sctp_cmd_seq_t *commands)
3760 struct sctp_chunk *chunk = arg;
3761 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3762 struct sctp_fwdtsn_skip *skip;
3766 if (!sctp_vtag_verify(chunk, asoc)) {
3767 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3769 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3772 /* Make sure that the FORWARD_TSN chunk has valid length. */
3773 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3774 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3777 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3778 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3779 len = ntohs(chunk->chunk_hdr->length);
3780 len -= sizeof(struct sctp_chunkhdr);
3781 skb_pull(chunk->skb, len);
3783 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3784 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3786 /* The TSN is too high--silently discard the chunk and count on it
3787 * getting retransmitted later.
3789 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3790 goto discard_noforce;
3792 /* Silently discard the chunk if stream-id is not valid */
3793 sctp_walk_fwdtsn(skip, chunk) {
3794 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3795 goto discard_noforce;
3798 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3799 if (len > sizeof(struct sctp_fwdtsn_hdr))
3800 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3803 /* Count this as receiving DATA. */
3804 if (asoc->autoclose) {
3805 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3806 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3809 /* FIXME: For now send a SACK, but DATA processing may
3812 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3814 return SCTP_DISPOSITION_CONSUME;
3817 return SCTP_DISPOSITION_DISCARD;
3820 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3821 const struct sctp_endpoint *ep,
3822 const struct sctp_association *asoc,
3823 const sctp_subtype_t type,
3825 sctp_cmd_seq_t *commands)
3827 struct sctp_chunk *chunk = arg;
3828 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3829 struct sctp_fwdtsn_skip *skip;
3833 if (!sctp_vtag_verify(chunk, asoc)) {
3834 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3836 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3839 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3840 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3841 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3844 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3845 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3846 len = ntohs(chunk->chunk_hdr->length);
3847 len -= sizeof(struct sctp_chunkhdr);
3848 skb_pull(chunk->skb, len);
3850 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3851 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3853 /* The TSN is too high--silently discard the chunk and count on it
3854 * getting retransmitted later.
3856 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3859 /* Silently discard the chunk if stream-id is not valid */
3860 sctp_walk_fwdtsn(skip, chunk) {
3861 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3865 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3866 if (len > sizeof(struct sctp_fwdtsn_hdr))
3867 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3870 /* Go a head and force a SACK, since we are shutting down. */
3872 /* Implementor's Guide.
3874 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3875 * respond to each received packet containing one or more DATA chunk(s)
3876 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3878 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3879 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3880 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3881 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3883 return SCTP_DISPOSITION_CONSUME;
3887 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3889 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3890 * Identifier field. If this algorithm was not specified by the
3891 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3892 * during association setup, the AUTH chunk and all chunks after it MUST
3893 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3894 * defined in Section 4.1.
3896 * If an endpoint with no shared key receives a Shared Key Identifier
3897 * other than 0, it MUST silently discard all authenticated chunks. If
3898 * the endpoint has at least one endpoint pair shared key for the peer,
3899 * it MUST use the key specified by the Shared Key Identifier if a
3900 * key has been configured for that Shared Key Identifier. If no
3901 * endpoint pair shared key has been configured for that Shared Key
3902 * Identifier, all authenticated chunks MUST be silently discarded.
3904 * Verification Tag: 8.5 Verification Tag [Normal verification]
3906 * The return value is the disposition of the chunk.
3908 static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3909 const struct sctp_association *asoc,
3910 const sctp_subtype_t type,
3911 struct sctp_chunk *chunk)
3913 struct sctp_authhdr *auth_hdr;
3914 struct sctp_hmac *hmac;
3915 unsigned int sig_len;
3920 /* Pull in the auth header, so we can do some more verification */
3921 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3922 chunk->subh.auth_hdr = auth_hdr;
3923 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3925 /* Make sure that we suport the HMAC algorithm from the auth
3928 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3929 return SCTP_IERROR_AUTH_BAD_HMAC;
3931 /* Make sure that the provided shared key identifier has been
3934 key_id = ntohs(auth_hdr->shkey_id);
3935 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3936 return SCTP_IERROR_AUTH_BAD_KEYID;
3939 /* Make sure that the length of the signature matches what
3942 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3943 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3944 if (sig_len != hmac->hmac_len)
3945 return SCTP_IERROR_PROTO_VIOLATION;
3947 /* Now that we've done validation checks, we can compute and
3948 * verify the hmac. The steps involved are:
3949 * 1. Save the digest from the chunk.
3950 * 2. Zero out the digest in the chunk.
3951 * 3. Compute the new digest
3952 * 4. Compare saved and new digests.
3954 digest = auth_hdr->hmac;
3955 skb_pull(chunk->skb, sig_len);
3957 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3961 memset(digest, 0, sig_len);
3963 sctp_auth_calculate_hmac(asoc, chunk->skb,
3964 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3967 /* Discard the packet if the digests do not match */
3968 if (memcmp(save_digest, digest, sig_len)) {
3970 return SCTP_IERROR_BAD_SIG;
3976 return SCTP_IERROR_NO_ERROR;
3978 return SCTP_IERROR_NOMEM;
3981 sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3982 const struct sctp_association *asoc,
3983 const sctp_subtype_t type,
3985 sctp_cmd_seq_t *commands)
3987 struct sctp_authhdr *auth_hdr;
3988 struct sctp_chunk *chunk = arg;
3989 struct sctp_chunk *err_chunk;
3990 sctp_ierror_t error;
3992 /* Make sure that the peer has AUTH capable */
3993 if (!asoc->peer.auth_capable)
3994 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
3996 if (!sctp_vtag_verify(chunk, asoc)) {
3997 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3999 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4002 /* Make sure that the AUTH chunk has valid length. */
4003 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4004 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4007 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4008 error = sctp_sf_authenticate(ep, asoc, type, chunk);
4010 case SCTP_IERROR_AUTH_BAD_HMAC:
4011 /* Generate the ERROR chunk and discard the rest
4014 err_chunk = sctp_make_op_error(asoc, chunk,
4015 SCTP_ERROR_UNSUP_HMAC,
4019 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4020 SCTP_CHUNK(err_chunk));
4023 case SCTP_IERROR_AUTH_BAD_KEYID:
4024 case SCTP_IERROR_BAD_SIG:
4025 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4027 case SCTP_IERROR_PROTO_VIOLATION:
4028 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4031 case SCTP_IERROR_NOMEM:
4032 return SCTP_DISPOSITION_NOMEM;
4034 default: /* Prevent gcc warnings */
4038 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4039 struct sctp_ulpevent *ev;
4041 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4042 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4047 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4051 return SCTP_DISPOSITION_CONSUME;
4055 * Process an unknown chunk.
4057 * Section: 3.2. Also, 2.1 in the implementor's guide.
4059 * Chunk Types are encoded such that the highest-order two bits specify
4060 * the action that must be taken if the processing endpoint does not
4061 * recognize the Chunk Type.
4063 * 00 - Stop processing this SCTP packet and discard it, do not process
4064 * any further chunks within it.
4066 * 01 - Stop processing this SCTP packet and discard it, do not process
4067 * any further chunks within it, and report the unrecognized
4068 * chunk in an 'Unrecognized Chunk Type'.
4070 * 10 - Skip this chunk and continue processing.
4072 * 11 - Skip this chunk and continue processing, but report in an ERROR
4073 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4075 * The return value is the disposition of the chunk.
4077 sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
4078 const struct sctp_association *asoc,
4079 const sctp_subtype_t type,
4081 sctp_cmd_seq_t *commands)
4083 struct sctp_chunk *unk_chunk = arg;
4084 struct sctp_chunk *err_chunk;
4085 sctp_chunkhdr_t *hdr;
4087 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
4089 if (!sctp_vtag_verify(unk_chunk, asoc))
4090 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4092 /* Make sure that the chunk has a valid length.
4093 * Since we don't know the chunk type, we use a general
4094 * chunkhdr structure to make a comparison.
4096 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4097 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4100 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4101 case SCTP_CID_ACTION_DISCARD:
4102 /* Discard the packet. */
4103 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4105 case SCTP_CID_ACTION_DISCARD_ERR:
4106 /* Generate an ERROR chunk as response. */
4107 hdr = unk_chunk->chunk_hdr;
4108 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4109 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4110 WORD_ROUND(ntohs(hdr->length)),
4113 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4114 SCTP_CHUNK(err_chunk));
4117 /* Discard the packet. */
4118 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4119 return SCTP_DISPOSITION_CONSUME;
4121 case SCTP_CID_ACTION_SKIP:
4122 /* Skip the chunk. */
4123 return SCTP_DISPOSITION_DISCARD;
4125 case SCTP_CID_ACTION_SKIP_ERR:
4126 /* Generate an ERROR chunk as response. */
4127 hdr = unk_chunk->chunk_hdr;
4128 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4129 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4130 WORD_ROUND(ntohs(hdr->length)),
4133 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4134 SCTP_CHUNK(err_chunk));
4136 /* Skip the chunk. */
4137 return SCTP_DISPOSITION_CONSUME;
4143 return SCTP_DISPOSITION_DISCARD;
4147 * Discard the chunk.
4149 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4150 * [Too numerous to mention...]
4151 * Verification Tag: No verification needed.
4153 * (endpoint, asoc, chunk)
4156 * (asoc, reply_msg, msg_up, timers, counters)
4158 * The return value is the disposition of the chunk.
4160 sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4161 const struct sctp_association *asoc,
4162 const sctp_subtype_t type,
4164 sctp_cmd_seq_t *commands)
4166 struct sctp_chunk *chunk = arg;
4168 /* Make sure that the chunk has a valid length.
4169 * Since we don't know the chunk type, we use a general
4170 * chunkhdr structure to make a comparison.
4172 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4173 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4176 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4177 return SCTP_DISPOSITION_DISCARD;
4181 * Discard the whole packet.
4185 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4186 * silently discard the OOTB packet and take no further action.
4188 * Verification Tag: No verification necessary
4191 * (endpoint, asoc, chunk)
4194 * (asoc, reply_msg, msg_up, timers, counters)
4196 * The return value is the disposition of the chunk.
4198 sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4199 const struct sctp_association *asoc,
4200 const sctp_subtype_t type,
4202 sctp_cmd_seq_t *commands)
4204 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
4205 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4207 return SCTP_DISPOSITION_CONSUME;
4212 * The other end is violating protocol.
4214 * Section: Not specified
4215 * Verification Tag: Not specified
4217 * (endpoint, asoc, chunk)
4220 * (asoc, reply_msg, msg_up, timers, counters)
4222 * We simply tag the chunk as a violation. The state machine will log
4223 * the violation and continue.
4225 sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4226 const struct sctp_association *asoc,
4227 const sctp_subtype_t type,
4229 sctp_cmd_seq_t *commands)
4231 struct sctp_chunk *chunk = arg;
4233 /* Make sure that the chunk has a valid length. */
4234 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4235 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4238 return SCTP_DISPOSITION_VIOLATION;
4242 * Common function to handle a protocol violation.
4244 static sctp_disposition_t sctp_sf_abort_violation(
4245 const struct sctp_endpoint *ep,
4246 const struct sctp_association *asoc,
4248 sctp_cmd_seq_t *commands,
4249 const __u8 *payload,
4250 const size_t paylen)
4252 struct sctp_packet *packet = NULL;
4253 struct sctp_chunk *chunk = arg;
4254 struct sctp_chunk *abort = NULL;
4256 /* SCTP-AUTH, Section 6.3:
4257 * It should be noted that if the receiver wants to tear
4258 * down an association in an authenticated way only, the
4259 * handling of malformed packets should not result in
4260 * tearing down the association.
4262 * This means that if we only want to abort associations
4263 * in an authenticated way (i.e AUTH+ABORT), then we
4264 * can't destroy this association just because the packet
4267 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4270 /* Make the abort chunk. */
4271 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4276 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4277 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4278 !asoc->peer.i.init_tag) {
4279 sctp_initack_chunk_t *initack;
4281 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4282 if (!sctp_chunk_length_valid(chunk,
4283 sizeof(sctp_initack_chunk_t)))
4284 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4286 unsigned int inittag;
4288 inittag = ntohl(initack->init_hdr.init_tag);
4289 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4294 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4295 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4297 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4298 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4299 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4300 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4301 SCTP_ERROR(ECONNREFUSED));
4302 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4303 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4305 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4306 SCTP_ERROR(ECONNABORTED));
4307 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4308 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4309 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4312 packet = sctp_ootb_pkt_new(asoc, chunk);
4317 if (sctp_test_T_bit(abort))
4318 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4320 abort->skb->sk = ep->base.sk;
4322 sctp_packet_append_chunk(packet, abort);
4324 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4325 SCTP_PACKET(packet));
4327 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4330 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4333 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4334 return SCTP_DISPOSITION_ABORT;
4337 sctp_chunk_free(abort);
4339 return SCTP_DISPOSITION_NOMEM;
4343 * Handle a protocol violation when the chunk length is invalid.
4344 * "Invalid" length is identified as smaller than the minimal length a
4345 * given chunk can be. For example, a SACK chunk has invalid length
4346 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4348 * We inform the other end by sending an ABORT with a Protocol Violation
4351 * Section: Not specified
4352 * Verification Tag: Nothing to do
4354 * (endpoint, asoc, chunk)
4357 * (reply_msg, msg_up, counters)
4359 * Generate an ABORT chunk and terminate the association.
4361 static sctp_disposition_t sctp_sf_violation_chunklen(
4362 const struct sctp_endpoint *ep,
4363 const struct sctp_association *asoc,
4364 const sctp_subtype_t type,
4366 sctp_cmd_seq_t *commands)
4368 static const char err_str[]="The following chunk had invalid length:";
4370 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4375 * Handle a protocol violation when the parameter length is invalid.
4376 * If the length is smaller than the minimum length of a given parameter,
4377 * or accumulated length in multi parameters exceeds the end of the chunk,
4378 * the length is considered as invalid.
4380 static sctp_disposition_t sctp_sf_violation_paramlen(
4381 const struct sctp_endpoint *ep,
4382 const struct sctp_association *asoc,
4383 const sctp_subtype_t type,
4384 void *arg, void *ext,
4385 sctp_cmd_seq_t *commands)
4387 struct sctp_chunk *chunk = arg;
4388 struct sctp_paramhdr *param = ext;
4389 struct sctp_chunk *abort = NULL;
4391 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4394 /* Make the abort chunk. */
4395 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4399 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4400 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4402 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4403 SCTP_ERROR(ECONNABORTED));
4404 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4405 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4406 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4407 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4410 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4411 return SCTP_DISPOSITION_ABORT;
4413 return SCTP_DISPOSITION_NOMEM;
4416 /* Handle a protocol violation when the peer trying to advance the
4417 * cumulative tsn ack to a point beyond the max tsn currently sent.
4419 * We inform the other end by sending an ABORT with a Protocol Violation
4422 static sctp_disposition_t sctp_sf_violation_ctsn(
4423 const struct sctp_endpoint *ep,
4424 const struct sctp_association *asoc,
4425 const sctp_subtype_t type,
4427 sctp_cmd_seq_t *commands)
4429 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
4431 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4435 /* Handle protocol violation of an invalid chunk bundling. For example,
4436 * when we have an association and we receive bundled INIT-ACK, or
4437 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4438 * statement from the specs. Additionally, there might be an attacker
4439 * on the path and we may not want to continue this communication.
4441 static sctp_disposition_t sctp_sf_violation_chunk(
4442 const struct sctp_endpoint *ep,
4443 const struct sctp_association *asoc,
4444 const sctp_subtype_t type,
4446 sctp_cmd_seq_t *commands)
4448 static const char err_str[]="The following chunk violates protocol:";
4451 return sctp_sf_violation(ep, asoc, type, arg, commands);
4453 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4456 /***************************************************************************
4457 * These are the state functions for handling primitive (Section 10) events.
4458 ***************************************************************************/
4460 * sctp_sf_do_prm_asoc
4462 * Section: 10.1 ULP-to-SCTP
4465 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4466 * outbound stream count)
4467 * -> association id [,destination transport addr list] [,outbound stream
4470 * This primitive allows the upper layer to initiate an association to a
4471 * specific peer endpoint.
4473 * The peer endpoint shall be specified by one of the transport addresses
4474 * which defines the endpoint (see Section 1.4). If the local SCTP
4475 * instance has not been initialized, the ASSOCIATE is considered an
4477 * [This is not relevant for the kernel implementation since we do all
4478 * initialization at boot time. It we hadn't initialized we wouldn't
4479 * get anywhere near this code.]
4481 * An association id, which is a local handle to the SCTP association,
4482 * will be returned on successful establishment of the association. If
4483 * SCTP is not able to open an SCTP association with the peer endpoint,
4484 * an error is returned.
4485 * [In the kernel implementation, the struct sctp_association needs to
4486 * be created BEFORE causing this primitive to run.]
4488 * Other association parameters may be returned, including the
4489 * complete destination transport addresses of the peer as well as the
4490 * outbound stream count of the local endpoint. One of the transport
4491 * address from the returned destination addresses will be selected by
4492 * the local endpoint as default primary path for sending SCTP packets
4493 * to this peer. The returned "destination transport addr list" can
4494 * be used by the ULP to change the default primary path or to force
4495 * sending a packet to a specific transport address. [All of this
4496 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4499 * Mandatory attributes:
4501 * o local SCTP instance name - obtained from the INITIALIZE operation.
4502 * [This is the argument asoc.]
4503 * o destination transport addr - specified as one of the transport
4504 * addresses of the peer endpoint with which the association is to be
4506 * [This is asoc->peer.active_path.]
4507 * o outbound stream count - the number of outbound streams the ULP
4508 * would like to open towards this peer endpoint.
4509 * [BUG: This is not currently implemented.]
4510 * Optional attributes:
4514 * The return value is a disposition.
4516 sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4517 const struct sctp_association *asoc,
4518 const sctp_subtype_t type,
4520 sctp_cmd_seq_t *commands)
4522 struct sctp_chunk *repl;
4523 struct sctp_association* my_asoc;
4525 /* The comment below says that we enter COOKIE-WAIT AFTER
4526 * sending the INIT, but that doesn't actually work in our
4529 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4530 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4532 /* RFC 2960 5.1 Normal Establishment of an Association
4534 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4535 * must provide its Verification Tag (Tag_A) in the Initiate
4536 * Tag field. Tag_A SHOULD be a random number in the range of
4537 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4540 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4544 /* Cast away the const modifier, as we want to just
4545 * rerun it through as a sideffect.
4547 my_asoc = (struct sctp_association *)asoc;
4548 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4550 /* Choose transport for INIT. */
4551 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4554 /* After sending the INIT, "A" starts the T1-init timer and
4555 * enters the COOKIE-WAIT state.
4557 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4558 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4559 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4560 return SCTP_DISPOSITION_CONSUME;
4563 return SCTP_DISPOSITION_NOMEM;
4567 * Process the SEND primitive.
4569 * Section: 10.1 ULP-to-SCTP
4572 * Format: SEND(association id, buffer address, byte count [,context]
4573 * [,stream id] [,life time] [,destination transport address]
4574 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4577 * This is the main method to send user data via SCTP.
4579 * Mandatory attributes:
4581 * o association id - local handle to the SCTP association
4583 * o buffer address - the location where the user message to be
4584 * transmitted is stored;
4586 * o byte count - The size of the user data in number of bytes;
4588 * Optional attributes:
4590 * o context - an optional 32 bit integer that will be carried in the
4591 * sending failure notification to the ULP if the transportation of
4592 * this User Message fails.
4594 * o stream id - to indicate which stream to send the data on. If not
4595 * specified, stream 0 will be used.
4597 * o life time - specifies the life time of the user data. The user data
4598 * will not be sent by SCTP after the life time expires. This
4599 * parameter can be used to avoid efforts to transmit stale
4600 * user messages. SCTP notifies the ULP if the data cannot be
4601 * initiated to transport (i.e. sent to the destination via SCTP's
4602 * send primitive) within the life time variable. However, the
4603 * user data will be transmitted if SCTP has attempted to transmit a
4604 * chunk before the life time expired.
4606 * o destination transport address - specified as one of the destination
4607 * transport addresses of the peer endpoint to which this packet
4608 * should be sent. Whenever possible, SCTP should use this destination
4609 * transport address for sending the packets, instead of the current
4612 * o unorder flag - this flag, if present, indicates that the user
4613 * would like the data delivered in an unordered fashion to the peer
4614 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4617 * o no-bundle flag - instructs SCTP not to bundle this user data with
4618 * other outbound DATA chunks. SCTP MAY still bundle even when
4619 * this flag is present, when faced with network congestion.
4621 * o payload protocol-id - A 32 bit unsigned integer that is to be
4622 * passed to the peer indicating the type of payload protocol data
4623 * being transmitted. This value is passed as opaque data by SCTP.
4625 * The return value is the disposition.
4627 sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4628 const struct sctp_association *asoc,
4629 const sctp_subtype_t type,
4631 sctp_cmd_seq_t *commands)
4633 struct sctp_datamsg *msg = arg;
4635 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4636 return SCTP_DISPOSITION_CONSUME;
4640 * Process the SHUTDOWN primitive.
4645 * Format: SHUTDOWN(association id)
4648 * Gracefully closes an association. Any locally queued user data
4649 * will be delivered to the peer. The association will be terminated only
4650 * after the peer acknowledges all the SCTP packets sent. A success code
4651 * will be returned on successful termination of the association. If
4652 * attempting to terminate the association results in a failure, an error
4653 * code shall be returned.
4655 * Mandatory attributes:
4657 * o association id - local handle to the SCTP association
4659 * Optional attributes:
4663 * The return value is the disposition.
4665 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4666 const struct sctp_endpoint *ep,
4667 const struct sctp_association *asoc,
4668 const sctp_subtype_t type,
4670 sctp_cmd_seq_t *commands)
4674 /* From 9.2 Shutdown of an Association
4675 * Upon receipt of the SHUTDOWN primitive from its upper
4676 * layer, the endpoint enters SHUTDOWN-PENDING state and
4677 * remains there until all outstanding data has been
4678 * acknowledged by its peer. The endpoint accepts no new data
4679 * from its upper layer, but retransmits data to the far end
4680 * if necessary to fill gaps.
4682 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4683 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4685 disposition = SCTP_DISPOSITION_CONSUME;
4686 if (sctp_outq_is_empty(&asoc->outqueue)) {
4687 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4694 * Process the ABORT primitive.
4699 * Format: Abort(association id [, cause code])
4702 * Ungracefully closes an association. Any locally queued user data
4703 * will be discarded and an ABORT chunk is sent to the peer. A success code
4704 * will be returned on successful abortion of the association. If
4705 * attempting to abort the association results in a failure, an error
4706 * code shall be returned.
4708 * Mandatory attributes:
4710 * o association id - local handle to the SCTP association
4712 * Optional attributes:
4714 * o cause code - reason of the abort to be passed to the peer
4718 * The return value is the disposition.
4720 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4721 const struct sctp_endpoint *ep,
4722 const struct sctp_association *asoc,
4723 const sctp_subtype_t type,
4725 sctp_cmd_seq_t *commands)
4727 /* From 9.1 Abort of an Association
4728 * Upon receipt of the ABORT primitive from its upper
4729 * layer, the endpoint enters CLOSED state and
4730 * discard all outstanding data has been
4731 * acknowledged by its peer. The endpoint accepts no new data
4732 * from its upper layer, but retransmits data to the far end
4733 * if necessary to fill gaps.
4735 struct sctp_chunk *abort = arg;
4736 sctp_disposition_t retval;
4738 retval = SCTP_DISPOSITION_CONSUME;
4740 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4742 /* Even if we can't send the ABORT due to low memory delete the
4743 * TCB. This is a departure from our typical NOMEM handling.
4746 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4747 SCTP_ERROR(ECONNABORTED));
4748 /* Delete the established association. */
4749 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4750 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4752 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4753 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4758 /* We tried an illegal operation on an association which is closed. */
4759 sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4760 const struct sctp_association *asoc,
4761 const sctp_subtype_t type,
4763 sctp_cmd_seq_t *commands)
4765 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4766 return SCTP_DISPOSITION_CONSUME;
4769 /* We tried an illegal operation on an association which is shutting
4772 sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4773 const struct sctp_association *asoc,
4774 const sctp_subtype_t type,
4776 sctp_cmd_seq_t *commands)
4778 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4779 SCTP_ERROR(-ESHUTDOWN));
4780 return SCTP_DISPOSITION_CONSUME;
4784 * sctp_cookie_wait_prm_shutdown
4786 * Section: 4 Note: 2
4791 * The RFC does not explicitly address this issue, but is the route through the
4792 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4797 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4798 const struct sctp_endpoint *ep,
4799 const struct sctp_association *asoc,
4800 const sctp_subtype_t type,
4802 sctp_cmd_seq_t *commands)
4804 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4805 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4807 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4808 SCTP_STATE(SCTP_STATE_CLOSED));
4810 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4812 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4814 return SCTP_DISPOSITION_DELETE_TCB;
4818 * sctp_cookie_echoed_prm_shutdown
4820 * Section: 4 Note: 2
4825 * The RFC does not explcitly address this issue, but is the route through the
4826 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4831 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4832 const struct sctp_endpoint *ep,
4833 const struct sctp_association *asoc,
4834 const sctp_subtype_t type,
4835 void *arg, sctp_cmd_seq_t *commands)
4837 /* There is a single T1 timer, so we should be able to use
4838 * common function with the COOKIE-WAIT state.
4840 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4844 * sctp_sf_cookie_wait_prm_abort
4846 * Section: 4 Note: 2
4851 * The RFC does not explicitly address this issue, but is the route through the
4852 * state table when someone issues an abort while in COOKIE_WAIT state.
4857 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4858 const struct sctp_endpoint *ep,
4859 const struct sctp_association *asoc,
4860 const sctp_subtype_t type,
4862 sctp_cmd_seq_t *commands)
4864 struct sctp_chunk *abort = arg;
4865 sctp_disposition_t retval;
4867 /* Stop T1-init timer */
4868 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4869 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4870 retval = SCTP_DISPOSITION_CONSUME;
4872 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4874 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4875 SCTP_STATE(SCTP_STATE_CLOSED));
4877 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4879 /* Even if we can't send the ABORT due to low memory delete the
4880 * TCB. This is a departure from our typical NOMEM handling.
4883 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4884 SCTP_ERROR(ECONNREFUSED));
4885 /* Delete the established association. */
4886 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4887 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4893 * sctp_sf_cookie_echoed_prm_abort
4895 * Section: 4 Note: 3
4900 * The RFC does not explcitly address this issue, but is the route through the
4901 * state table when someone issues an abort while in COOKIE_ECHOED state.
4906 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4907 const struct sctp_endpoint *ep,
4908 const struct sctp_association *asoc,
4909 const sctp_subtype_t type,
4911 sctp_cmd_seq_t *commands)
4913 /* There is a single T1 timer, so we should be able to use
4914 * common function with the COOKIE-WAIT state.
4916 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4920 * sctp_sf_shutdown_pending_prm_abort
4925 * The RFC does not explicitly address this issue, but is the route through the
4926 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4931 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
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 /* Stop the T5-shutdown guard timer. */
4939 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4940 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4942 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4946 * sctp_sf_shutdown_sent_prm_abort
4951 * The RFC does not explicitly address this issue, but is the route through the
4952 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4957 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4958 const struct sctp_endpoint *ep,
4959 const struct sctp_association *asoc,
4960 const sctp_subtype_t type,
4962 sctp_cmd_seq_t *commands)
4964 /* Stop the T2-shutdown timer. */
4965 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4966 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4968 /* Stop the T5-shutdown guard timer. */
4969 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4970 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4972 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4976 * sctp_sf_cookie_echoed_prm_abort
4981 * The RFC does not explcitly address this issue, but is the route through the
4982 * state table when someone issues an abort while in COOKIE_ECHOED state.
4987 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4988 const struct sctp_endpoint *ep,
4989 const struct sctp_association *asoc,
4990 const sctp_subtype_t type,
4992 sctp_cmd_seq_t *commands)
4994 /* The same T2 timer, so we should be able to use
4995 * common function with the SHUTDOWN-SENT state.
4997 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
5001 * Process the REQUESTHEARTBEAT primitive
5004 * J) Request Heartbeat
5006 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5010 * Instructs the local endpoint to perform a HeartBeat on the specified
5011 * destination transport address of the given association. The returned
5012 * result should indicate whether the transmission of the HEARTBEAT
5013 * chunk to the destination address is successful.
5015 * Mandatory attributes:
5017 * o association id - local handle to the SCTP association
5019 * o destination transport address - the transport address of the
5020 * association on which a heartbeat should be issued.
5022 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5023 const struct sctp_endpoint *ep,
5024 const struct sctp_association *asoc,
5025 const sctp_subtype_t type,
5027 sctp_cmd_seq_t *commands)
5029 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5030 (struct sctp_transport *)arg, commands))
5031 return SCTP_DISPOSITION_NOMEM;
5034 * RFC 2960 (bis), section 8.3
5036 * D) Request an on-demand HEARTBEAT on a specific destination
5037 * transport address of a given association.
5039 * The endpoint should increment the respective error counter of
5040 * the destination transport address each time a HEARTBEAT is sent
5041 * to that address and not acknowledged within one RTO.
5044 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5045 SCTP_TRANSPORT(arg));
5046 return SCTP_DISPOSITION_CONSUME;
5050 * ADDIP Section 4.1 ASCONF Chunk Procedures
5051 * When an endpoint has an ASCONF signaled change to be sent to the
5052 * remote endpoint it should do A1 to A9
5054 sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
5055 const struct sctp_association *asoc,
5056 const sctp_subtype_t type,
5058 sctp_cmd_seq_t *commands)
5060 struct sctp_chunk *chunk = arg;
5062 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5063 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5064 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5065 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5066 return SCTP_DISPOSITION_CONSUME;
5070 * Ignore the primitive event
5072 * The return value is the disposition of the primitive.
5074 sctp_disposition_t sctp_sf_ignore_primitive(
5075 const struct sctp_endpoint *ep,
5076 const struct sctp_association *asoc,
5077 const sctp_subtype_t type,
5079 sctp_cmd_seq_t *commands)
5081 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
5082 return SCTP_DISPOSITION_DISCARD;
5085 /***************************************************************************
5086 * These are the state functions for the OTHER events.
5087 ***************************************************************************/
5090 * When the SCTP stack has no more user data to send or retransmit, this
5091 * notification is given to the user. Also, at the time when a user app
5092 * subscribes to this event, if there is no data to be sent or
5093 * retransmit, the stack will immediately send up this notification.
5095 sctp_disposition_t sctp_sf_do_no_pending_tsn(
5096 const struct sctp_endpoint *ep,
5097 const struct sctp_association *asoc,
5098 const sctp_subtype_t type,
5100 sctp_cmd_seq_t *commands)
5102 struct sctp_ulpevent *event;
5104 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5106 return SCTP_DISPOSITION_NOMEM;
5108 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5110 return SCTP_DISPOSITION_CONSUME;
5114 * Start the shutdown negotiation.
5117 * Once all its outstanding data has been acknowledged, the endpoint
5118 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5119 * TSN Ack field the last sequential TSN it has received from the peer.
5120 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5121 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5122 * with the updated last sequential TSN received from its peer.
5124 * The return value is the disposition.
5126 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5127 const struct sctp_endpoint *ep,
5128 const struct sctp_association *asoc,
5129 const sctp_subtype_t type,
5131 sctp_cmd_seq_t *commands)
5133 struct sctp_chunk *reply;
5135 /* Once all its outstanding data has been acknowledged, the
5136 * endpoint shall send a SHUTDOWN chunk to its peer including
5137 * in the Cumulative TSN Ack field the last sequential TSN it
5138 * has received from the peer.
5140 reply = sctp_make_shutdown(asoc, NULL);
5144 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5145 * T2-shutdown timer.
5147 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5149 /* It shall then start the T2-shutdown timer */
5150 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5151 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5153 /* RFC 4960 Section 9.2
5154 * The sender of the SHUTDOWN MAY also start an overall guard timer
5155 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5157 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5158 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5160 if (asoc->autoclose)
5161 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5162 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5164 /* and enter the SHUTDOWN-SENT state. */
5165 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5166 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5168 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5170 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5173 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5175 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5177 return SCTP_DISPOSITION_CONSUME;
5180 return SCTP_DISPOSITION_NOMEM;
5184 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5188 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5189 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5190 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5191 * endpoint must re-send the SHUTDOWN ACK.
5193 * The return value is the disposition.
5195 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5196 const struct sctp_endpoint *ep,
5197 const struct sctp_association *asoc,
5198 const sctp_subtype_t type,
5200 sctp_cmd_seq_t *commands)
5202 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5203 struct sctp_chunk *reply;
5205 /* There are 2 ways of getting here:
5206 * 1) called in response to a SHUTDOWN chunk
5207 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5209 * For the case (2), the arg parameter is set to NULL. We need
5210 * to check that we have a chunk before accessing it's fields.
5213 if (!sctp_vtag_verify(chunk, asoc))
5214 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5216 /* Make sure that the SHUTDOWN chunk has a valid length. */
5217 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5218 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5222 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5223 * shall send a SHUTDOWN ACK ...
5225 reply = sctp_make_shutdown_ack(asoc, chunk);
5229 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5230 * the T2-shutdown timer.
5232 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5234 /* and start/restart a T2-shutdown timer of its own, */
5235 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5236 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5238 if (asoc->autoclose)
5239 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5240 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5242 /* Enter the SHUTDOWN-ACK-SENT state. */
5243 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5244 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5246 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5248 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5251 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5253 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5255 return SCTP_DISPOSITION_CONSUME;
5258 return SCTP_DISPOSITION_NOMEM;
5262 * Ignore the event defined as other
5264 * The return value is the disposition of the event.
5266 sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5267 const struct sctp_association *asoc,
5268 const sctp_subtype_t type,
5270 sctp_cmd_seq_t *commands)
5272 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5273 return SCTP_DISPOSITION_DISCARD;
5276 /************************************************************
5277 * These are the state functions for handling timeout events.
5278 ************************************************************/
5283 * Section: 6.3.3 Handle T3-rtx Expiration
5285 * Whenever the retransmission timer T3-rtx expires for a destination
5286 * address, do the following:
5289 * The return value is the disposition of the chunk.
5291 sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5292 const struct sctp_association *asoc,
5293 const sctp_subtype_t type,
5295 sctp_cmd_seq_t *commands)
5297 struct sctp_transport *transport = arg;
5299 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5301 if (asoc->overall_error_count >= asoc->max_retrans) {
5302 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5304 * We are here likely because the receiver had its rwnd
5305 * closed for a while and we have not been able to
5306 * transmit the locally queued data within the maximum
5307 * retransmission attempts limit. Start the T5
5308 * shutdown guard timer to give the receiver one last
5309 * chance and some additional time to recover before
5312 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5313 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5315 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5316 SCTP_ERROR(ETIMEDOUT));
5317 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5318 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5319 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5320 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5321 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5322 return SCTP_DISPOSITION_DELETE_TCB;
5326 /* E1) For the destination address for which the timer
5327 * expires, adjust its ssthresh with rules defined in Section
5328 * 7.2.3 and set the cwnd <- MTU.
5331 /* E2) For the destination address for which the timer
5332 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5333 * maximum value discussed in rule C7 above (RTO.max) may be
5334 * used to provide an upper bound to this doubling operation.
5337 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5338 * outstanding DATA chunks for the address for which the
5339 * T3-rtx has expired will fit into a single packet, subject
5340 * to the MTU constraint for the path corresponding to the
5341 * destination transport address to which the retransmission
5342 * is being sent (this may be different from the address for
5343 * which the timer expires [see Section 6.4]). Call this
5344 * value K. Bundle and retransmit those K DATA chunks in a
5345 * single packet to the destination endpoint.
5347 * Note: Any DATA chunks that were sent to the address for
5348 * which the T3-rtx timer expired but did not fit in one MTU
5349 * (rule E3 above), should be marked for retransmission and
5350 * sent as soon as cwnd allows (normally when a SACK arrives).
5353 /* Do some failure management (Section 8.2). */
5354 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5356 /* NB: Rules E4 and F1 are implicit in R1. */
5357 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5359 return SCTP_DISPOSITION_CONSUME;
5363 * Generate delayed SACK on timeout
5365 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5367 * The guidelines on delayed acknowledgement algorithm specified in
5368 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5369 * acknowledgement SHOULD be generated for at least every second packet
5370 * (not every second DATA chunk) received, and SHOULD be generated
5371 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5372 * some situations it may be beneficial for an SCTP transmitter to be
5373 * more conservative than the algorithms detailed in this document
5374 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5375 * the following algorithms allow.
5377 sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5378 const struct sctp_association *asoc,
5379 const sctp_subtype_t type,
5381 sctp_cmd_seq_t *commands)
5383 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
5384 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5385 return SCTP_DISPOSITION_CONSUME;
5389 * sctp_sf_t1_init_timer_expire
5391 * Section: 4 Note: 2
5396 * RFC 2960 Section 4 Notes
5397 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5398 * and re-start the T1-init timer without changing state. This MUST
5399 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5400 * endpoint MUST abort the initialization process and report the
5401 * error to SCTP user.
5407 sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5408 const struct sctp_association *asoc,
5409 const sctp_subtype_t type,
5411 sctp_cmd_seq_t *commands)
5413 struct sctp_chunk *repl = NULL;
5414 struct sctp_bind_addr *bp;
5415 int attempts = asoc->init_err_counter + 1;
5417 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5418 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
5420 if (attempts <= asoc->max_init_attempts) {
5421 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5422 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5424 return SCTP_DISPOSITION_NOMEM;
5426 /* Choose transport for INIT. */
5427 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5430 /* Issue a sideeffect to do the needed accounting. */
5431 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5432 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5434 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5436 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5437 " max_init_attempts: %d\n",
5438 attempts, asoc->max_init_attempts);
5439 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5440 SCTP_ERROR(ETIMEDOUT));
5441 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5442 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5443 return SCTP_DISPOSITION_DELETE_TCB;
5446 return SCTP_DISPOSITION_CONSUME;
5450 * sctp_sf_t1_cookie_timer_expire
5452 * Section: 4 Note: 2
5457 * RFC 2960 Section 4 Notes
5458 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5459 * COOKIE ECHO and re-start the T1-cookie timer without changing
5460 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5461 * After that, the endpoint MUST abort the initialization process and
5462 * report the error to SCTP user.
5468 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
5469 const struct sctp_association *asoc,
5470 const sctp_subtype_t type,
5472 sctp_cmd_seq_t *commands)
5474 struct sctp_chunk *repl = NULL;
5475 int attempts = asoc->init_err_counter + 1;
5477 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5478 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
5480 if (attempts <= asoc->max_init_attempts) {
5481 repl = sctp_make_cookie_echo(asoc, NULL);
5483 return SCTP_DISPOSITION_NOMEM;
5485 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5487 /* Issue a sideeffect to do the needed accounting. */
5488 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5489 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5491 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5493 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5494 SCTP_ERROR(ETIMEDOUT));
5495 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5496 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5497 return SCTP_DISPOSITION_DELETE_TCB;
5500 return SCTP_DISPOSITION_CONSUME;
5503 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5504 * with the updated last sequential TSN received from its peer.
5506 * An endpoint should limit the number of retransmissions of the
5507 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5508 * If this threshold is exceeded the endpoint should destroy the TCB and
5509 * MUST report the peer endpoint unreachable to the upper layer (and
5510 * thus the association enters the CLOSED state). The reception of any
5511 * packet from its peer (i.e. as the peer sends all of its queued DATA
5512 * chunks) should clear the endpoint's retransmission count and restart
5513 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5514 * all of its queued DATA chunks that have not yet been sent.
5516 sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5517 const struct sctp_association *asoc,
5518 const sctp_subtype_t type,
5520 sctp_cmd_seq_t *commands)
5522 struct sctp_chunk *reply = NULL;
5524 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5525 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5527 ((struct sctp_association *)asoc)->shutdown_retries++;
5529 if (asoc->overall_error_count >= asoc->max_retrans) {
5530 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5531 SCTP_ERROR(ETIMEDOUT));
5532 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5533 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5534 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5535 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5536 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5537 return SCTP_DISPOSITION_DELETE_TCB;
5540 switch (asoc->state) {
5541 case SCTP_STATE_SHUTDOWN_SENT:
5542 reply = sctp_make_shutdown(asoc, NULL);
5545 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5546 reply = sctp_make_shutdown_ack(asoc, NULL);
5557 /* Do some failure management (Section 8.2).
5558 * If we remove the transport an SHUTDOWN was last sent to, don't
5559 * do failure management.
5561 if (asoc->shutdown_last_sent_to)
5562 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5563 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5565 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5566 * the T2-shutdown timer.
5568 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5570 /* Restart the T2-shutdown timer. */
5571 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5572 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5573 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5574 return SCTP_DISPOSITION_CONSUME;
5577 return SCTP_DISPOSITION_NOMEM;
5581 * ADDIP Section 4.1 ASCONF CHunk Procedures
5582 * If the T4 RTO timer expires the endpoint should do B1 to B5
5584 sctp_disposition_t sctp_sf_t4_timer_expire(
5585 const struct sctp_endpoint *ep,
5586 const struct sctp_association *asoc,
5587 const sctp_subtype_t type,
5589 sctp_cmd_seq_t *commands)
5591 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5592 struct sctp_transport *transport = chunk->transport;
5594 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5596 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5597 * detection on the appropriate destination address as defined in
5598 * RFC2960 [5] section 8.1 and 8.2.
5601 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5602 SCTP_TRANSPORT(transport));
5604 /* Reconfig T4 timer and transport. */
5605 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5607 /* ADDIP 4.1 B2) Increment the association error counters and perform
5608 * endpoint failure detection on the association as defined in
5609 * RFC2960 [5] section 8.1 and 8.2.
5610 * association error counter is incremented in SCTP_CMD_STRIKE.
5612 if (asoc->overall_error_count >= asoc->max_retrans) {
5613 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5614 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5615 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5616 SCTP_ERROR(ETIMEDOUT));
5617 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5618 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5619 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5620 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5621 return SCTP_DISPOSITION_ABORT;
5624 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5625 * the ASCONF chunk was sent by doubling the RTO timer value.
5626 * This is done in SCTP_CMD_STRIKE.
5629 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5630 * choose an alternate destination address (please refer to RFC2960
5631 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5632 * chunk, it MUST be the same (including its serial number) as the last
5635 sctp_chunk_hold(asoc->addip_last_asconf);
5636 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5637 SCTP_CHUNK(asoc->addip_last_asconf));
5639 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5640 * destination is selected, then the RTO used will be that of the new
5641 * destination address.
5643 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5644 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5646 return SCTP_DISPOSITION_CONSUME;
5649 /* sctpimpguide-05 Section 2.12.2
5650 * The sender of the SHUTDOWN MAY also start an overall guard timer
5651 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5652 * At the expiration of this timer the sender SHOULD abort the association
5653 * by sending an ABORT chunk.
5655 sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5656 const struct sctp_association *asoc,
5657 const sctp_subtype_t type,
5659 sctp_cmd_seq_t *commands)
5661 struct sctp_chunk *reply = NULL;
5663 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5664 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5666 reply = sctp_make_abort(asoc, NULL, 0);
5670 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5671 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5672 SCTP_ERROR(ETIMEDOUT));
5673 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5674 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5676 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5677 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5679 return SCTP_DISPOSITION_DELETE_TCB;
5681 return SCTP_DISPOSITION_NOMEM;
5684 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5685 * the association is automatically closed by starting the shutdown process.
5686 * The work that needs to be done is same as when SHUTDOWN is initiated by
5687 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5689 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5690 const struct sctp_endpoint *ep,
5691 const struct sctp_association *asoc,
5692 const sctp_subtype_t type,
5694 sctp_cmd_seq_t *commands)
5698 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5700 /* From 9.2 Shutdown of an Association
5701 * Upon receipt of the SHUTDOWN primitive from its upper
5702 * layer, the endpoint enters SHUTDOWN-PENDING state and
5703 * remains there until all outstanding data has been
5704 * acknowledged by its peer. The endpoint accepts no new data
5705 * from its upper layer, but retransmits data to the far end
5706 * if necessary to fill gaps.
5708 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5709 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5711 disposition = SCTP_DISPOSITION_CONSUME;
5712 if (sctp_outq_is_empty(&asoc->outqueue)) {
5713 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5719 /*****************************************************************************
5720 * These are sa state functions which could apply to all types of events.
5721 ****************************************************************************/
5724 * This table entry is not implemented.
5727 * (endpoint, asoc, chunk)
5729 * The return value is the disposition of the chunk.
5731 sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5732 const struct sctp_association *asoc,
5733 const sctp_subtype_t type,
5735 sctp_cmd_seq_t *commands)
5737 return SCTP_DISPOSITION_NOT_IMPL;
5741 * This table entry represents a bug.
5744 * (endpoint, asoc, chunk)
5746 * The return value is the disposition of the chunk.
5748 sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5749 const struct sctp_association *asoc,
5750 const sctp_subtype_t type,
5752 sctp_cmd_seq_t *commands)
5754 return SCTP_DISPOSITION_BUG;
5758 * This table entry represents the firing of a timer in the wrong state.
5759 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5760 * when the association is in the wrong state. This event should
5761 * be ignored, so as to prevent any rearming of the timer.
5764 * (endpoint, asoc, chunk)
5766 * The return value is the disposition of the chunk.
5768 sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5769 const struct sctp_association *asoc,
5770 const sctp_subtype_t type,
5772 sctp_cmd_seq_t *commands)
5774 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5775 return SCTP_DISPOSITION_CONSUME;
5778 /********************************************************************
5779 * 2nd Level Abstractions
5780 ********************************************************************/
5782 /* Pull the SACK chunk based on the SACK header. */
5783 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5785 struct sctp_sackhdr *sack;
5790 /* Protect ourselves from reading too far into
5791 * the skb from a bogus sender.
5793 sack = (struct sctp_sackhdr *) chunk->skb->data;
5795 num_blocks = ntohs(sack->num_gap_ack_blocks);
5796 num_dup_tsns = ntohs(sack->num_dup_tsns);
5797 len = sizeof(struct sctp_sackhdr);
5798 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5799 if (len > chunk->skb->len)
5802 skb_pull(chunk->skb, len);
5807 /* Create an ABORT packet to be sent as a response, with the specified
5810 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5811 const struct sctp_association *asoc,
5812 struct sctp_chunk *chunk,
5813 const void *payload,
5816 struct sctp_packet *packet;
5817 struct sctp_chunk *abort;
5819 packet = sctp_ootb_pkt_new(asoc, chunk);
5823 * The T bit will be set if the asoc is NULL.
5825 abort = sctp_make_abort(asoc, chunk, paylen);
5827 sctp_ootb_pkt_free(packet);
5831 /* Reflect vtag if T-Bit is set */
5832 if (sctp_test_T_bit(abort))
5833 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5835 /* Add specified error causes, i.e., payload, to the
5838 sctp_addto_chunk(abort, paylen, payload);
5840 /* Set the skb to the belonging sock for accounting. */
5841 abort->skb->sk = ep->base.sk;
5843 sctp_packet_append_chunk(packet, abort);
5850 /* Allocate a packet for responding in the OOTB conditions. */
5851 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5852 const struct sctp_chunk *chunk)
5854 struct sctp_packet *packet;
5855 struct sctp_transport *transport;
5860 /* Get the source and destination port from the inbound packet. */
5861 sport = ntohs(chunk->sctp_hdr->dest);
5862 dport = ntohs(chunk->sctp_hdr->source);
5864 /* The V-tag is going to be the same as the inbound packet if no
5865 * association exists, otherwise, use the peer's vtag.
5868 /* Special case the INIT-ACK as there is no peer's vtag
5871 switch(chunk->chunk_hdr->type) {
5872 case SCTP_CID_INIT_ACK:
5874 sctp_initack_chunk_t *initack;
5876 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5877 vtag = ntohl(initack->init_hdr.init_tag);
5881 vtag = asoc->peer.i.init_tag;
5885 /* Special case the INIT and stale COOKIE_ECHO as there is no
5888 switch(chunk->chunk_hdr->type) {
5891 sctp_init_chunk_t *init;
5893 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5894 vtag = ntohl(init->init_hdr.init_tag);
5898 vtag = ntohl(chunk->sctp_hdr->vtag);
5903 /* Make a transport for the bucket, Eliza... */
5904 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5908 /* Cache a route for the transport with the chunk's destination as
5909 * the source address.
5911 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5912 sctp_sk(sctp_get_ctl_sock()));
5914 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5915 packet = sctp_packet_config(packet, vtag, 0);
5923 /* Free the packet allocated earlier for responding in the OOTB condition. */
5924 void sctp_ootb_pkt_free(struct sctp_packet *packet)
5926 sctp_transport_free(packet->transport);
5929 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5930 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5931 const struct sctp_association *asoc,
5932 const struct sctp_chunk *chunk,
5933 sctp_cmd_seq_t *commands,
5934 struct sctp_chunk *err_chunk)
5936 struct sctp_packet *packet;
5939 packet = sctp_ootb_pkt_new(asoc, chunk);
5941 struct sctp_signed_cookie *cookie;
5943 /* Override the OOTB vtag from the cookie. */
5944 cookie = chunk->subh.cookie_hdr;
5945 packet->vtag = cookie->c.peer_vtag;
5947 /* Set the skb to the belonging sock for accounting. */
5948 err_chunk->skb->sk = ep->base.sk;
5949 sctp_packet_append_chunk(packet, err_chunk);
5950 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5951 SCTP_PACKET(packet));
5952 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5954 sctp_chunk_free (err_chunk);
5959 /* Process a data chunk */
5960 static int sctp_eat_data(const struct sctp_association *asoc,
5961 struct sctp_chunk *chunk,
5962 sctp_cmd_seq_t *commands)
5964 sctp_datahdr_t *data_hdr;
5965 struct sctp_chunk *err;
5967 sctp_verb_t deliver;
5970 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
5971 struct sock *sk = asoc->base.sk;
5976 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5977 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5979 tsn = ntohl(data_hdr->tsn);
5980 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5982 /* ASSERT: Now skb->data is really the user data. */
5984 /* Process ECN based congestion.
5986 * Since the chunk structure is reused for all chunks within
5987 * a packet, we use ecn_ce_done to track if we've already
5988 * done CE processing for this packet.
5990 * We need to do ECN processing even if we plan to discard the
5994 if (!chunk->ecn_ce_done) {
5996 chunk->ecn_ce_done = 1;
5998 af = sctp_get_af_specific(
5999 ipver2af(ip_hdr(chunk->skb)->version));
6001 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6002 /* Do real work as sideffect. */
6003 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6008 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6010 /* The TSN is too high--silently discard the chunk and
6011 * count on it getting retransmitted later.
6013 return SCTP_IERROR_HIGH_TSN;
6014 } else if (tmp > 0) {
6015 /* This is a duplicate. Record it. */
6016 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6017 return SCTP_IERROR_DUP_TSN;
6020 /* This is a new TSN. */
6022 /* Discard if there is no room in the receive window.
6023 * Actually, allow a little bit of overflow (up to a MTU).
6025 datalen = ntohs(chunk->chunk_hdr->length);
6026 datalen -= sizeof(sctp_data_chunk_t);
6028 deliver = SCTP_CMD_CHUNK_ULP;
6030 /* Think about partial delivery. */
6031 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6033 /* Even if we don't accept this chunk there is
6036 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6039 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6040 * seems a bit troublesome in that frag_point varies based on
6041 * PMTU. In cases, such as loopback, this might be a rather
6044 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6045 (datalen > asoc->rwnd + asoc->frag_point))) {
6047 /* If this is the next TSN, consider reneging to make
6048 * room. Note: Playing nice with a confused sender. A
6049 * malicious sender can still eat up all our buffer
6050 * space and in the future we may want to detect and
6051 * do more drastic reneging.
6053 if (sctp_tsnmap_has_gap(map) &&
6054 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6055 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
6056 deliver = SCTP_CMD_RENEGE;
6058 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6059 "rwnd: %d\n", tsn, datalen,
6061 return SCTP_IERROR_IGNORE_TSN;
6066 * Also try to renege to limit our memory usage in the event that
6067 * we are under memory pressure
6068 * If we can't renege, don't worry about it, the sk_rmem_schedule
6069 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6070 * memory usage too much
6072 if (*sk->sk_prot_creator->memory_pressure) {
6073 if (sctp_tsnmap_has_gap(map) &&
6074 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6075 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
6076 deliver = SCTP_CMD_RENEGE;
6081 * Section 3.3.10.9 No User Data (9)
6085 * No User Data: This error cause is returned to the originator of a
6086 * DATA chunk if a received DATA chunk has no user data.
6088 if (unlikely(0 == datalen)) {
6089 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6091 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6094 /* We are going to ABORT, so we might as well stop
6095 * processing the rest of the chunks in the packet.
6097 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
6098 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6099 SCTP_ERROR(ECONNABORTED));
6100 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6101 SCTP_PERR(SCTP_ERROR_NO_DATA));
6102 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
6103 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
6104 return SCTP_IERROR_NO_DATA;
6107 chunk->data_accepted = 1;
6109 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6110 * if we renege and the chunk arrives again.
6112 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
6113 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
6115 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
6119 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6121 * If an endpoint receive a DATA chunk with an invalid stream
6122 * identifier, it shall acknowledge the reception of the DATA chunk
6123 * following the normal procedure, immediately send an ERROR chunk
6124 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6125 * and discard the DATA chunk.
6127 sid = ntohs(data_hdr->stream);
6128 if (sid >= asoc->c.sinit_max_instreams) {
6129 /* Mark tsn as received even though we drop it */
6130 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6132 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6134 sizeof(data_hdr->stream),
6137 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6139 return SCTP_IERROR_BAD_STREAM;
6142 /* Check to see if the SSN is possible for this TSN.
6143 * The biggest gap we can record is 4K wide. Since SSNs wrap
6144 * at an unsigned short, there is no way that an SSN can
6145 * wrap and for a valid TSN. We can simply check if the current
6146 * SSN is smaller then the next expected one. If it is, it wrapped
6149 ssn = ntohs(data_hdr->ssn);
6150 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6151 return SCTP_IERROR_PROTO_VIOLATION;
6154 /* Send the data up to the user. Note: Schedule the
6155 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6156 * chunk needs the updated rwnd.
6158 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6160 return SCTP_IERROR_NO_ERROR;