1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
8 * This is part of the SCTP Linux Kernel Implementation.
10 * These are the state functions for the state machine.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Mathew Kotowsky <kotowsky@sctp.org>
36 * Sridhar Samudrala <samudrala@us.ibm.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Kevin Gao <kevin.gao@intel.com>
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 #include <linux/types.h>
49 #include <linux/kernel.h>
51 #include <linux/ipv6.h>
52 #include <linux/net.h>
53 #include <linux/inet.h>
54 #include <linux/slab.h>
56 #include <net/inet_ecn.h>
57 #include <linux/skbuff.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60 #include <net/sctp/structs.h>
62 static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
63 const struct sctp_endpoint *ep,
64 const struct sctp_association *asoc,
65 struct sctp_chunk *chunk,
68 static int sctp_eat_data(const struct sctp_association *asoc,
69 struct sctp_chunk *chunk,
70 sctp_cmd_seq_t *commands);
71 static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
72 const struct sctp_association *asoc,
73 const struct sctp_chunk *chunk);
74 static void sctp_send_stale_cookie_err(struct net *net,
75 const struct sctp_endpoint *ep,
76 const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk,
78 sctp_cmd_seq_t *commands,
79 struct sctp_chunk *err_chunk);
80 static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
81 const struct sctp_endpoint *ep,
82 const struct sctp_association *asoc,
83 const sctp_subtype_t type,
85 sctp_cmd_seq_t *commands);
86 static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
87 const struct sctp_endpoint *ep,
88 const struct sctp_association *asoc,
89 const sctp_subtype_t type,
91 sctp_cmd_seq_t *commands);
92 static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
93 const struct sctp_endpoint *ep,
94 const struct sctp_association *asoc,
95 const sctp_subtype_t type,
97 sctp_cmd_seq_t *commands);
98 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
100 static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
101 sctp_cmd_seq_t *commands,
102 __be16 error, int sk_err,
103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
106 static sctp_disposition_t sctp_sf_abort_violation(
108 const struct sctp_endpoint *ep,
109 const struct sctp_association *asoc,
111 sctp_cmd_seq_t *commands,
113 const size_t paylen);
115 static sctp_disposition_t sctp_sf_violation_chunklen(
117 const struct sctp_endpoint *ep,
118 const struct sctp_association *asoc,
119 const sctp_subtype_t type,
121 sctp_cmd_seq_t *commands);
123 static sctp_disposition_t sctp_sf_violation_paramlen(
125 const struct sctp_endpoint *ep,
126 const struct sctp_association *asoc,
127 const sctp_subtype_t type,
128 void *arg, void *ext,
129 sctp_cmd_seq_t *commands);
131 static sctp_disposition_t sctp_sf_violation_ctsn(
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const sctp_subtype_t type,
137 sctp_cmd_seq_t *commands);
139 static sctp_disposition_t sctp_sf_violation_chunk(
141 const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const sctp_subtype_t type,
145 sctp_cmd_seq_t *commands);
147 static sctp_ierror_t sctp_sf_authenticate(struct net *net,
148 const struct sctp_endpoint *ep,
149 const struct sctp_association *asoc,
150 const sctp_subtype_t type,
151 struct sctp_chunk *chunk);
153 static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
154 const struct sctp_endpoint *ep,
155 const struct sctp_association *asoc,
156 const sctp_subtype_t type,
158 sctp_cmd_seq_t *commands);
160 /* Small helper function that checks if the chunk length
161 * is of the appropriate length. The 'required_length' argument
162 * is set to be the size of a specific chunk we are testing.
163 * Return Values: true = Valid length
164 * false = Invalid length
168 sctp_chunk_length_valid(struct sctp_chunk *chunk, __u16 required_length)
170 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
172 /* Previously already marked? */
173 if (unlikely(chunk->pdiscard))
175 if (unlikely(chunk_length < required_length))
181 /**********************************************************
182 * These are the state functions for handling chunk events.
183 **********************************************************/
186 * Process the final SHUTDOWN COMPLETE.
188 * Section: 4 (C) (diagram), 9.2
189 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
190 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
191 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
192 * should stop the T2-shutdown timer and remove all knowledge of the
193 * association (and thus the association enters the CLOSED state).
195 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
196 * C) Rules for packet carrying SHUTDOWN COMPLETE:
198 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
199 * if the Verification Tag field of the packet matches its own tag and
200 * the T bit is not set
202 * it is set to its peer's tag and the T bit is set in the Chunk
204 * Otherwise, the receiver MUST silently discard the packet
205 * and take no further action. An endpoint MUST ignore the
206 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
209 * (endpoint, asoc, chunk)
212 * (asoc, reply_msg, msg_up, timers, counters)
214 * The return value is the disposition of the chunk.
216 sctp_disposition_t sctp_sf_do_4_C(struct net *net,
217 const struct sctp_endpoint *ep,
218 const struct sctp_association *asoc,
219 const sctp_subtype_t type,
221 sctp_cmd_seq_t *commands)
223 struct sctp_chunk *chunk = arg;
224 struct sctp_ulpevent *ev;
226 if (!sctp_vtag_verify_either(chunk, asoc))
227 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
229 /* RFC 2960 6.10 Bundling
231 * An endpoint MUST NOT bundle INIT, INIT ACK or
232 * SHUTDOWN COMPLETE with any other chunks.
234 if (!chunk->singleton)
235 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
237 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
238 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
239 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
242 /* RFC 2960 10.2 SCTP-to-ULP
244 * H) SHUTDOWN COMPLETE notification
246 * When SCTP completes the shutdown procedures (section 9.2) this
247 * notification is passed to the upper layer.
249 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
250 0, 0, 0, NULL, GFP_ATOMIC);
252 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
255 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
256 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
257 * not the chunk should be discarded. If the endpoint is in
258 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
259 * T2-shutdown timer and remove all knowledge of the
260 * association (and thus the association enters the CLOSED
263 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
264 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
266 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
267 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
269 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
270 SCTP_STATE(SCTP_STATE_CLOSED));
272 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
273 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
275 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
277 return SCTP_DISPOSITION_DELETE_TCB;
281 * Respond to a normal INIT chunk.
282 * We are the side that is being asked for an association.
284 * Section: 5.1 Normal Establishment of an Association, B
285 * B) "Z" shall respond immediately with an INIT ACK chunk. The
286 * destination IP address of the INIT ACK MUST be set to the source
287 * IP address of the INIT to which this INIT ACK is responding. In
288 * the response, besides filling in other parameters, "Z" must set the
289 * Verification Tag field to Tag_A, and also provide its own
290 * Verification Tag (Tag_Z) in the Initiate Tag field.
292 * Verification Tag: Must be 0.
295 * (endpoint, asoc, chunk)
298 * (asoc, reply_msg, msg_up, timers, counters)
300 * The return value is the disposition of the chunk.
302 sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
303 const struct sctp_endpoint *ep,
304 const struct sctp_association *asoc,
305 const sctp_subtype_t type,
307 sctp_cmd_seq_t *commands)
309 struct sctp_chunk *chunk = arg;
310 struct sctp_chunk *repl;
311 struct sctp_association *new_asoc;
312 struct sctp_chunk *err_chunk;
313 struct sctp_packet *packet;
314 sctp_unrecognized_param_t *unk_param;
318 * An endpoint MUST NOT bundle INIT, INIT ACK or
319 * SHUTDOWN COMPLETE with any other chunks.
322 * Furthermore, we require that the receiver of an INIT chunk MUST
323 * enforce these rules by silently discarding an arriving packet
324 * with an INIT chunk that is bundled with other chunks.
326 if (!chunk->singleton)
327 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
329 /* If the packet is an OOTB packet which is temporarily on the
330 * control endpoint, respond with an ABORT.
332 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
333 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
334 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
337 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
340 if (chunk->sctp_hdr->vtag != 0)
341 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
343 /* Make sure that the INIT chunk has a valid length.
344 * Normally, this would cause an ABORT with a Protocol Violation
345 * error, but since we don't have an association, we'll
346 * just discard the packet.
348 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
349 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
351 /* If the INIT is coming toward a closing socket, we'll send back
352 * and ABORT. Essentially, this catches the race of INIT being
353 * backloged to the socket at the same time as the user isses close().
354 * Since the socket and all its associations are going away, we
355 * can treat this OOTB
357 if (sctp_sstate(ep->base.sk, CLOSING))
358 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
360 /* Verify the INIT chunk before processing it. */
362 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
363 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
365 /* This chunk contains fatal error. It is to be discarded.
366 * Send an ABORT, with causes if there is any.
369 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
370 (__u8 *)(err_chunk->chunk_hdr) +
371 sizeof(sctp_chunkhdr_t),
372 ntohs(err_chunk->chunk_hdr->length) -
373 sizeof(sctp_chunkhdr_t));
375 sctp_chunk_free(err_chunk);
378 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
379 SCTP_PACKET(packet));
380 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
381 return SCTP_DISPOSITION_CONSUME;
383 return SCTP_DISPOSITION_NOMEM;
386 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
391 /* Grab the INIT header. */
392 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
394 /* Tag the variable length parameters. */
395 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
397 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
401 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
402 sctp_scope(sctp_source(chunk)),
406 /* The call, sctp_process_init(), can fail on memory allocation. */
407 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
408 (sctp_init_chunk_t *)chunk->chunk_hdr,
412 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
414 /* If there are errors need to be reported for unknown parameters,
415 * make sure to reserve enough room in the INIT ACK for them.
419 len = ntohs(err_chunk->chunk_hdr->length) -
420 sizeof(sctp_chunkhdr_t);
422 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
426 /* If there are errors need to be reported for unknown parameters,
427 * include them in the outgoing INIT ACK as "Unrecognized parameter"
431 /* Get the "Unrecognized parameter" parameter(s) out of the
432 * ERROR chunk generated by sctp_verify_init(). Since the
433 * error cause code for "unknown parameter" and the
434 * "Unrecognized parameter" type is the same, we can
435 * construct the parameters in INIT ACK by copying the
438 unk_param = (sctp_unrecognized_param_t *)
439 ((__u8 *)(err_chunk->chunk_hdr) +
440 sizeof(sctp_chunkhdr_t));
441 /* Replace the cause code with the "Unrecognized parameter"
444 sctp_addto_chunk(repl, len, unk_param);
445 sctp_chunk_free(err_chunk);
448 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
450 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
453 * Note: After sending out INIT ACK with the State Cookie parameter,
454 * "Z" MUST NOT allocate any resources, nor keep any states for the
455 * new association. Otherwise, "Z" will be vulnerable to resource
458 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
460 return SCTP_DISPOSITION_DELETE_TCB;
463 sctp_association_free(new_asoc);
466 sctp_chunk_free(err_chunk);
467 return SCTP_DISPOSITION_NOMEM;
471 * Respond to a normal INIT ACK chunk.
472 * We are the side that is initiating the association.
474 * Section: 5.1 Normal Establishment of an Association, C
475 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
476 * timer and leave COOKIE-WAIT state. "A" shall then send the State
477 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
478 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
480 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
481 * DATA chunks, but it MUST be the first chunk in the packet and
482 * until the COOKIE ACK is returned the sender MUST NOT send any
483 * other packets to the peer.
485 * Verification Tag: 3.3.3
486 * If the value of the Initiate Tag in a received INIT ACK chunk is
487 * found to be 0, the receiver MUST treat it as an error and close the
488 * association by transmitting an ABORT.
491 * (endpoint, asoc, chunk)
494 * (asoc, reply_msg, msg_up, timers, counters)
496 * The return value is the disposition of the chunk.
498 sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
499 const struct sctp_endpoint *ep,
500 const struct sctp_association *asoc,
501 const sctp_subtype_t type,
503 sctp_cmd_seq_t *commands)
505 struct sctp_chunk *chunk = arg;
506 sctp_init_chunk_t *initchunk;
507 struct sctp_chunk *err_chunk;
508 struct sctp_packet *packet;
510 if (!sctp_vtag_verify(chunk, asoc))
511 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
514 * An endpoint MUST NOT bundle INIT, INIT ACK or
515 * SHUTDOWN COMPLETE with any other chunks.
517 if (!chunk->singleton)
518 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
520 /* Make sure that the INIT-ACK chunk has a valid length */
521 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
522 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
524 /* Grab the INIT header. */
525 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
527 /* Verify the INIT chunk before processing it. */
529 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
530 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
533 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
535 /* This chunk contains fatal error. It is to be discarded.
536 * Send an ABORT, with causes. If there are no causes,
537 * then there wasn't enough memory. Just terminate
541 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
542 (__u8 *)(err_chunk->chunk_hdr) +
543 sizeof(sctp_chunkhdr_t),
544 ntohs(err_chunk->chunk_hdr->length) -
545 sizeof(sctp_chunkhdr_t));
547 sctp_chunk_free(err_chunk);
550 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
551 SCTP_PACKET(packet));
552 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
553 error = SCTP_ERROR_INV_PARAM;
557 /* SCTP-AUTH, Section 6.3:
558 * It should be noted that if the receiver wants to tear
559 * down an association in an authenticated way only, the
560 * handling of malformed packets should not result in
561 * tearing down the association.
563 * This means that if we only want to abort associations
564 * in an authenticated way (i.e AUTH+ABORT), then we
565 * can't destroy this association just because the packet
568 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
569 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
571 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
572 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
573 asoc, chunk->transport);
576 /* Tag the variable length parameters. Note that we never
577 * convert the parameters in an INIT chunk.
579 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
581 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
583 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
584 SCTP_PEER_INIT(initchunk));
586 /* Reset init error count upon receipt of INIT-ACK. */
587 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
589 /* 5.1 C) "A" shall stop the T1-init timer and leave
590 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
591 * timer, and enter the COOKIE-ECHOED state.
593 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
595 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
596 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
597 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
598 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
600 /* SCTP-AUTH: genereate the assocition shared keys so that
601 * we can potentially signe the COOKIE-ECHO.
603 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
605 /* 5.1 C) "A" shall then send the State Cookie received in the
606 * INIT ACK chunk in a COOKIE ECHO chunk, ...
608 /* If there is any errors to report, send the ERROR chunk generated
609 * for unknown parameters as well.
611 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
612 SCTP_CHUNK(err_chunk));
614 return SCTP_DISPOSITION_CONSUME;
618 * Respond to a normal COOKIE ECHO chunk.
619 * We are the side that is being asked for an association.
621 * Section: 5.1 Normal Establishment of an Association, D
622 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
623 * with a COOKIE ACK chunk after building a TCB and moving to
624 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
625 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
626 * chunk MUST be the first chunk in the packet.
628 * IMPLEMENTATION NOTE: An implementation may choose to send the
629 * Communication Up notification to the SCTP user upon reception
630 * of a valid COOKIE ECHO chunk.
632 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
633 * D) Rules for packet carrying a COOKIE ECHO
635 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
636 * Initial Tag received in the INIT ACK.
638 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
641 * (endpoint, asoc, chunk)
644 * (asoc, reply_msg, msg_up, timers, counters)
646 * The return value is the disposition of the chunk.
648 sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
649 const struct sctp_endpoint *ep,
650 const struct sctp_association *asoc,
651 const sctp_subtype_t type, void *arg,
652 sctp_cmd_seq_t *commands)
654 struct sctp_chunk *chunk = arg;
655 struct sctp_association *new_asoc;
656 sctp_init_chunk_t *peer_init;
657 struct sctp_chunk *repl;
658 struct sctp_ulpevent *ev, *ai_ev = NULL;
660 struct sctp_chunk *err_chk_p;
663 /* If the packet is an OOTB packet which is temporarily on the
664 * control endpoint, respond with an ABORT.
666 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
667 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
668 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
671 /* Make sure that the COOKIE_ECHO chunk has a valid length.
672 * In this case, we check that we have enough for at least a
673 * chunk header. More detailed verification is done
674 * in sctp_unpack_cookie().
676 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
677 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
679 /* If the endpoint is not listening or if the number of associations
680 * on the TCP-style socket exceed the max backlog, respond with an
684 if (!sctp_sstate(sk, LISTENING) ||
685 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
686 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
688 /* "Decode" the chunk. We have no optional parameters so we
691 chunk->subh.cookie_hdr =
692 (struct sctp_signed_cookie *)chunk->skb->data;
693 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
694 sizeof(sctp_chunkhdr_t)))
697 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
698 * "Z" will reply with a COOKIE ACK chunk after building a TCB
699 * and moving to the ESTABLISHED state.
701 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
705 * If the re-build failed, what is the proper error path
708 * [We should abort the association. --piggy]
711 /* FIXME: Several errors are possible. A bad cookie should
712 * be silently discarded, but think about logging it too.
715 case -SCTP_IERROR_NOMEM:
718 case -SCTP_IERROR_STALE_COOKIE:
719 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
721 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
723 case -SCTP_IERROR_BAD_SIG:
725 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
730 /* Delay state machine commands until later.
732 * Re-build the bind address for the association is done in
733 * the sctp_unpack_cookie() already.
735 /* This is a brand-new association, so these are not yet side
736 * effects--it is safe to run them here.
738 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
740 if (!sctp_process_init(new_asoc, chunk,
741 &chunk->subh.cookie_hdr->c.peer_addr,
742 peer_init, GFP_ATOMIC))
745 /* SCTP-AUTH: Now that we've populate required fields in
746 * sctp_process_init, set up the assocaition shared keys as
747 * necessary so that we can potentially authenticate the ACK
749 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
753 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
754 * is supposed to be authenticated and we have to do delayed
755 * authentication. We've just recreated the association using
756 * the information in the cookie and now it's much easier to
757 * do the authentication.
759 if (chunk->auth_chunk) {
760 struct sctp_chunk auth;
763 /* Make sure that we and the peer are AUTH capable */
764 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
765 sctp_association_free(new_asoc);
766 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
769 /* set-up our fake chunk so that we can process it */
770 auth.skb = chunk->auth_chunk;
771 auth.asoc = chunk->asoc;
772 auth.sctp_hdr = chunk->sctp_hdr;
773 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
774 sizeof(sctp_chunkhdr_t));
775 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
776 auth.transport = chunk->transport;
778 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
779 if (ret != SCTP_IERROR_NO_ERROR) {
780 sctp_association_free(new_asoc);
781 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
785 repl = sctp_make_cookie_ack(new_asoc, chunk);
789 /* RFC 2960 5.1 Normal Establishment of an Association
791 * D) IMPLEMENTATION NOTE: An implementation may choose to
792 * send the Communication Up notification to the SCTP user
793 * upon reception of a valid COOKIE ECHO chunk.
795 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
796 new_asoc->c.sinit_num_ostreams,
797 new_asoc->c.sinit_max_instreams,
802 /* Sockets API Draft Section 5.3.1.6
803 * When a peer sends a Adaptation Layer Indication parameter , SCTP
804 * delivers this notification to inform the application that of the
805 * peers requested adaptation layer.
807 if (new_asoc->peer.adaptation_ind) {
808 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
814 /* Add all the state machine commands now since we've created
815 * everything. This way we don't introduce memory corruptions
816 * during side-effect processing and correclty count established
819 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
821 SCTP_STATE(SCTP_STATE_ESTABLISHED));
822 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
823 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
824 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
826 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
827 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
828 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
830 /* This will send the COOKIE ACK */
831 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
833 /* Queue the ASSOC_CHANGE event */
834 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
836 /* Send up the Adaptation Layer Indication event */
838 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
839 SCTP_ULPEVENT(ai_ev));
841 return SCTP_DISPOSITION_CONSUME;
844 sctp_ulpevent_free(ev);
846 sctp_chunk_free(repl);
848 sctp_association_free(new_asoc);
850 return SCTP_DISPOSITION_NOMEM;
854 * Respond to a normal COOKIE ACK chunk.
855 * We are the side that is asking for an association.
857 * RFC 2960 5.1 Normal Establishment of an Association
859 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
860 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
861 * timer. It may also notify its ULP about the successful
862 * establishment of the association with a Communication Up
863 * notification (see Section 10).
867 * (endpoint, asoc, chunk)
870 * (asoc, reply_msg, msg_up, timers, counters)
872 * The return value is the disposition of the chunk.
874 sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
875 const struct sctp_endpoint *ep,
876 const struct sctp_association *asoc,
877 const sctp_subtype_t type, void *arg,
878 sctp_cmd_seq_t *commands)
880 struct sctp_chunk *chunk = arg;
881 struct sctp_ulpevent *ev;
883 if (!sctp_vtag_verify(chunk, asoc))
884 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
886 /* Verify that the chunk length for the COOKIE-ACK is OK.
887 * If we don't do this, any bundled chunks may be junked.
889 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
890 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
893 /* Reset init error count upon receipt of COOKIE-ACK,
894 * to avoid problems with the managemement of this
895 * counter in stale cookie situations when a transition back
896 * from the COOKIE-ECHOED state to the COOKIE-WAIT
897 * state is performed.
899 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
901 /* RFC 2960 5.1 Normal Establishment of an Association
903 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
904 * from the COOKIE-ECHOED state to the ESTABLISHED state,
905 * stopping the T1-cookie timer.
907 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
908 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
909 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
910 SCTP_STATE(SCTP_STATE_ESTABLISHED));
911 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
912 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
913 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
914 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
915 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
916 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
918 /* It may also notify its ULP about the successful
919 * establishment of the association with a Communication Up
920 * notification (see Section 10).
922 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
923 0, asoc->c.sinit_num_ostreams,
924 asoc->c.sinit_max_instreams,
930 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
932 /* Sockets API Draft Section 5.3.1.6
933 * When a peer sends a Adaptation Layer Indication parameter , SCTP
934 * delivers this notification to inform the application that of the
935 * peers requested adaptation layer.
937 if (asoc->peer.adaptation_ind) {
938 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
942 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
946 return SCTP_DISPOSITION_CONSUME;
948 return SCTP_DISPOSITION_NOMEM;
951 /* Generate and sendout a heartbeat packet. */
952 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
953 const struct sctp_association *asoc,
954 const sctp_subtype_t type,
956 sctp_cmd_seq_t *commands)
958 struct sctp_transport *transport = (struct sctp_transport *) arg;
959 struct sctp_chunk *reply;
961 /* Send a heartbeat to our peer. */
962 reply = sctp_make_heartbeat(asoc, transport);
964 return SCTP_DISPOSITION_NOMEM;
966 /* Set rto_pending indicating that an RTT measurement
967 * is started with this heartbeat chunk.
969 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
970 SCTP_TRANSPORT(transport));
972 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
973 return SCTP_DISPOSITION_CONSUME;
976 /* Generate a HEARTBEAT packet on the given transport. */
977 sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
978 const struct sctp_endpoint *ep,
979 const struct sctp_association *asoc,
980 const sctp_subtype_t type,
982 sctp_cmd_seq_t *commands)
984 struct sctp_transport *transport = (struct sctp_transport *) arg;
986 if (asoc->overall_error_count >= asoc->max_retrans) {
987 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
988 SCTP_ERROR(ETIMEDOUT));
989 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
990 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
991 SCTP_PERR(SCTP_ERROR_NO_ERROR));
992 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
993 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
994 return SCTP_DISPOSITION_DELETE_TCB;
998 * The Sender-specific Heartbeat Info field should normally include
999 * information about the sender's current time when this HEARTBEAT
1000 * chunk is sent and the destination transport address to which this
1001 * HEARTBEAT is sent (see Section 8.3).
1004 if (transport->param_flags & SPP_HB_ENABLE) {
1005 if (SCTP_DISPOSITION_NOMEM ==
1006 sctp_sf_heartbeat(ep, asoc, type, arg,
1008 return SCTP_DISPOSITION_NOMEM;
1010 /* Set transport error counter and association error counter
1011 * when sending heartbeat.
1013 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1014 SCTP_TRANSPORT(transport));
1016 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1017 SCTP_TRANSPORT(transport));
1018 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1019 SCTP_TRANSPORT(transport));
1021 return SCTP_DISPOSITION_CONSUME;
1024 /* resend asoc strreset_chunk. */
1025 sctp_disposition_t sctp_sf_send_reconf(struct net *net,
1026 const struct sctp_endpoint *ep,
1027 const struct sctp_association *asoc,
1028 const sctp_subtype_t type, void *arg,
1029 sctp_cmd_seq_t *commands)
1031 struct sctp_transport *transport = arg;
1033 if (asoc->overall_error_count >= asoc->max_retrans) {
1034 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1035 SCTP_ERROR(ETIMEDOUT));
1036 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1037 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1038 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1039 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1040 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1041 return SCTP_DISPOSITION_DELETE_TCB;
1044 sctp_chunk_hold(asoc->strreset_chunk);
1045 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1046 SCTP_CHUNK(asoc->strreset_chunk));
1047 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
1049 return SCTP_DISPOSITION_CONSUME;
1053 * Process an heartbeat request.
1055 * Section: 8.3 Path Heartbeat
1056 * The receiver of the HEARTBEAT should immediately respond with a
1057 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1058 * from the received HEARTBEAT chunk.
1060 * Verification Tag: 8.5 Verification Tag [Normal verification]
1061 * When receiving an SCTP packet, the endpoint MUST ensure that the
1062 * value in the Verification Tag field of the received SCTP packet
1063 * matches its own Tag. If the received Verification Tag value does not
1064 * match the receiver's own tag value, the receiver shall silently
1065 * discard the packet and shall not process it any further except for
1066 * those cases listed in Section 8.5.1 below.
1069 * (endpoint, asoc, chunk)
1072 * (asoc, reply_msg, msg_up, timers, counters)
1074 * The return value is the disposition of the chunk.
1076 sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1077 const struct sctp_endpoint *ep,
1078 const struct sctp_association *asoc,
1079 const sctp_subtype_t type,
1081 sctp_cmd_seq_t *commands)
1083 sctp_paramhdr_t *param_hdr;
1084 struct sctp_chunk *chunk = arg;
1085 struct sctp_chunk *reply;
1088 if (!sctp_vtag_verify(chunk, asoc))
1089 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1091 /* Make sure that the HEARTBEAT chunk has a valid length. */
1092 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1093 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1096 /* 8.3 The receiver of the HEARTBEAT should immediately
1097 * respond with a HEARTBEAT ACK that contains the Heartbeat
1098 * Information field copied from the received HEARTBEAT chunk.
1100 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1101 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
1102 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1104 if (ntohs(param_hdr->length) > paylen)
1105 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1106 param_hdr, commands);
1108 if (!pskb_pull(chunk->skb, paylen))
1111 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1115 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1116 return SCTP_DISPOSITION_CONSUME;
1119 return SCTP_DISPOSITION_NOMEM;
1123 * Process the returning HEARTBEAT ACK.
1125 * Section: 8.3 Path Heartbeat
1126 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1127 * should clear the error counter of the destination transport
1128 * address to which the HEARTBEAT was sent, and mark the destination
1129 * transport address as active if it is not so marked. The endpoint may
1130 * optionally report to the upper layer when an inactive destination
1131 * address is marked as active due to the reception of the latest
1132 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1133 * clear the association overall error count as well (as defined
1136 * The receiver of the HEARTBEAT ACK should also perform an RTT
1137 * measurement for that destination transport address using the time
1138 * value carried in the HEARTBEAT ACK chunk.
1140 * Verification Tag: 8.5 Verification Tag [Normal verification]
1143 * (endpoint, asoc, chunk)
1146 * (asoc, reply_msg, msg_up, timers, counters)
1148 * The return value is the disposition of the chunk.
1150 sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1151 const struct sctp_endpoint *ep,
1152 const struct sctp_association *asoc,
1153 const sctp_subtype_t type,
1155 sctp_cmd_seq_t *commands)
1157 struct sctp_chunk *chunk = arg;
1158 union sctp_addr from_addr;
1159 struct sctp_transport *link;
1160 sctp_sender_hb_info_t *hbinfo;
1161 unsigned long max_interval;
1163 if (!sctp_vtag_verify(chunk, asoc))
1164 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1166 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1167 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1168 sizeof(sctp_sender_hb_info_t)))
1169 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1172 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1173 /* Make sure that the length of the parameter is what we expect */
1174 if (ntohs(hbinfo->param_hdr.length) !=
1175 sizeof(sctp_sender_hb_info_t)) {
1176 return SCTP_DISPOSITION_DISCARD;
1179 from_addr = hbinfo->daddr;
1180 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1182 /* This should never happen, but lets log it if so. */
1183 if (unlikely(!link)) {
1184 if (from_addr.sa.sa_family == AF_INET6) {
1185 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1188 &from_addr.v6.sin6_addr);
1190 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1193 &from_addr.v4.sin_addr.s_addr);
1195 return SCTP_DISPOSITION_DISCARD;
1198 /* Validate the 64-bit random nonce. */
1199 if (hbinfo->hb_nonce != link->hb_nonce)
1200 return SCTP_DISPOSITION_DISCARD;
1202 max_interval = link->hbinterval + link->rto;
1204 /* Check if the timestamp looks valid. */
1205 if (time_after(hbinfo->sent_at, jiffies) ||
1206 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1207 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1208 "for transport:%p\n", __func__, link);
1210 return SCTP_DISPOSITION_DISCARD;
1213 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1214 * the HEARTBEAT should clear the error counter of the
1215 * destination transport address to which the HEARTBEAT was
1216 * sent and mark the destination transport address as active if
1217 * it is not so marked.
1219 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1221 return SCTP_DISPOSITION_CONSUME;
1224 /* Helper function to send out an abort for the restart
1227 static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1228 struct sctp_chunk *init,
1229 sctp_cmd_seq_t *commands)
1232 struct sctp_packet *pkt;
1233 union sctp_addr_param *addrparm;
1234 struct sctp_errhdr *errhdr;
1235 struct sctp_endpoint *ep;
1236 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1237 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1239 /* Build the error on the stack. We are way to malloc crazy
1240 * throughout the code today.
1242 errhdr = (struct sctp_errhdr *)buffer;
1243 addrparm = (union sctp_addr_param *)errhdr->variable;
1245 /* Copy into a parm format. */
1246 len = af->to_addr_param(ssa, addrparm);
1247 len += sizeof(sctp_errhdr_t);
1249 errhdr->cause = SCTP_ERROR_RESTART;
1250 errhdr->length = htons(len);
1252 /* Assign to the control socket. */
1253 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1255 /* Association is NULL since this may be a restart attack and we
1256 * want to send back the attacker's vtag.
1258 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1262 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1264 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1266 /* Discard the rest of the inbound packet. */
1267 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1270 /* Even if there is no memory, treat as a failure so
1271 * the packet will get dropped.
1276 static bool list_has_sctp_addr(const struct list_head *list,
1277 union sctp_addr *ipaddr)
1279 struct sctp_transport *addr;
1281 list_for_each_entry(addr, list, transports) {
1282 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1288 /* A restart is occurring, check to make sure no new addresses
1289 * are being added as we may be under a takeover attack.
1291 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1292 const struct sctp_association *asoc,
1293 struct sctp_chunk *init,
1294 sctp_cmd_seq_t *commands)
1296 struct net *net = sock_net(new_asoc->base.sk);
1297 struct sctp_transport *new_addr;
1300 /* Implementor's Guide - Section 5.2.2
1302 * Before responding the endpoint MUST check to see if the
1303 * unexpected INIT adds new addresses to the association. If new
1304 * addresses are added to the association, the endpoint MUST respond
1308 /* Search through all current addresses and make sure
1309 * we aren't adding any new ones.
1311 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1313 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1314 &new_addr->ipaddr)) {
1315 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
1322 /* Return success if all addresses were found. */
1326 /* Populate the verification/tie tags based on overlapping INIT
1329 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1331 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1332 const struct sctp_association *asoc)
1334 switch (asoc->state) {
1336 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1338 case SCTP_STATE_COOKIE_WAIT:
1339 new_asoc->c.my_vtag = asoc->c.my_vtag;
1340 new_asoc->c.my_ttag = asoc->c.my_vtag;
1341 new_asoc->c.peer_ttag = 0;
1344 case SCTP_STATE_COOKIE_ECHOED:
1345 new_asoc->c.my_vtag = asoc->c.my_vtag;
1346 new_asoc->c.my_ttag = asoc->c.my_vtag;
1347 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1350 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1351 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1354 new_asoc->c.my_ttag = asoc->c.my_vtag;
1355 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1359 /* Other parameters for the endpoint SHOULD be copied from the
1360 * existing parameters of the association (e.g. number of
1361 * outbound streams) into the INIT ACK and cookie.
1363 new_asoc->rwnd = asoc->rwnd;
1364 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1365 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1366 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1370 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1373 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1375 * Returns value representing action to be taken. These action values
1376 * correspond to Action/Description values in RFC 2960, Table 2.
1378 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1379 const struct sctp_association *asoc)
1381 /* In this case, the peer may have restarted. */
1382 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1383 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1384 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1385 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1388 /* Collision case B. */
1389 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1390 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1391 (0 == asoc->c.peer_vtag))) {
1395 /* Collision case D. */
1396 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1397 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1400 /* Collision case C. */
1401 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1402 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1403 (0 == new_asoc->c.my_ttag) &&
1404 (0 == new_asoc->c.peer_ttag))
1407 /* No match to any of the special cases; discard this packet. */
1411 /* Common helper routine for both duplicate and simulataneous INIT
1414 static sctp_disposition_t sctp_sf_do_unexpected_init(
1416 const struct sctp_endpoint *ep,
1417 const struct sctp_association *asoc,
1418 const sctp_subtype_t type,
1419 void *arg, sctp_cmd_seq_t *commands)
1421 sctp_disposition_t retval;
1422 struct sctp_chunk *chunk = arg;
1423 struct sctp_chunk *repl;
1424 struct sctp_association *new_asoc;
1425 struct sctp_chunk *err_chunk;
1426 struct sctp_packet *packet;
1427 sctp_unrecognized_param_t *unk_param;
1431 * An endpoint MUST NOT bundle INIT, INIT ACK or
1432 * SHUTDOWN COMPLETE with any other chunks.
1435 * Furthermore, we require that the receiver of an INIT chunk MUST
1436 * enforce these rules by silently discarding an arriving packet
1437 * with an INIT chunk that is bundled with other chunks.
1439 if (!chunk->singleton)
1440 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1442 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1445 if (chunk->sctp_hdr->vtag != 0)
1446 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1448 /* Make sure that the INIT chunk has a valid length.
1449 * In this case, we generate a protocol violation since we have
1450 * an association established.
1452 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1453 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1455 /* Grab the INIT header. */
1456 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1458 /* Tag the variable length parameters. */
1459 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1461 /* Verify the INIT chunk before processing it. */
1463 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1464 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1466 /* This chunk contains fatal error. It is to be discarded.
1467 * Send an ABORT, with causes if there is any.
1470 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1471 (__u8 *)(err_chunk->chunk_hdr) +
1472 sizeof(sctp_chunkhdr_t),
1473 ntohs(err_chunk->chunk_hdr->length) -
1474 sizeof(sctp_chunkhdr_t));
1477 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1478 SCTP_PACKET(packet));
1479 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1480 retval = SCTP_DISPOSITION_CONSUME;
1482 retval = SCTP_DISPOSITION_NOMEM;
1486 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1492 * Other parameters for the endpoint SHOULD be copied from the
1493 * existing parameters of the association (e.g. number of
1494 * outbound streams) into the INIT ACK and cookie.
1495 * FIXME: We are copying parameters from the endpoint not the
1498 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1502 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1503 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1506 /* In the outbound INIT ACK the endpoint MUST copy its current
1507 * Verification Tag and Peers Verification tag into a reserved
1508 * place (local tie-tag and per tie-tag) within the state cookie.
1510 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1511 (sctp_init_chunk_t *)chunk->chunk_hdr,
1515 /* Make sure no new addresses are being added during the
1516 * restart. Do not do this check for COOKIE-WAIT state,
1517 * since there are no peer addresses to check against.
1518 * Upon return an ABORT will have been sent if needed.
1520 if (!sctp_state(asoc, COOKIE_WAIT)) {
1521 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1523 retval = SCTP_DISPOSITION_CONSUME;
1528 sctp_tietags_populate(new_asoc, asoc);
1530 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1532 /* If there are errors need to be reported for unknown parameters,
1533 * make sure to reserve enough room in the INIT ACK for them.
1537 len = ntohs(err_chunk->chunk_hdr->length) -
1538 sizeof(sctp_chunkhdr_t);
1541 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1545 /* If there are errors need to be reported for unknown parameters,
1546 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1550 /* Get the "Unrecognized parameter" parameter(s) out of the
1551 * ERROR chunk generated by sctp_verify_init(). Since the
1552 * error cause code for "unknown parameter" and the
1553 * "Unrecognized parameter" type is the same, we can
1554 * construct the parameters in INIT ACK by copying the
1555 * ERROR causes over.
1557 unk_param = (sctp_unrecognized_param_t *)
1558 ((__u8 *)(err_chunk->chunk_hdr) +
1559 sizeof(sctp_chunkhdr_t));
1560 /* Replace the cause code with the "Unrecognized parameter"
1563 sctp_addto_chunk(repl, len, unk_param);
1566 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1567 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1570 * Note: After sending out INIT ACK with the State Cookie parameter,
1571 * "Z" MUST NOT allocate any resources for this new association.
1572 * Otherwise, "Z" will be vulnerable to resource attacks.
1574 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1575 retval = SCTP_DISPOSITION_CONSUME;
1580 retval = SCTP_DISPOSITION_NOMEM;
1583 sctp_association_free(new_asoc);
1586 sctp_chunk_free(err_chunk);
1591 * Handle simultaneous INIT.
1592 * This means we started an INIT and then we got an INIT request from
1595 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1596 * This usually indicates an initialization collision, i.e., each
1597 * endpoint is attempting, at about the same time, to establish an
1598 * association with the other endpoint.
1600 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1601 * endpoint MUST respond with an INIT ACK using the same parameters it
1602 * sent in its original INIT chunk (including its Verification Tag,
1603 * unchanged). These original parameters are combined with those from the
1604 * newly received INIT chunk. The endpoint shall also generate a State
1605 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1606 * INIT to calculate the State Cookie.
1608 * After that, the endpoint MUST NOT change its state, the T1-init
1609 * timer shall be left running and the corresponding TCB MUST NOT be
1610 * destroyed. The normal procedures for handling State Cookies when
1611 * a TCB exists will resolve the duplicate INITs to a single association.
1613 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1614 * its Tie-Tags with the Tag information of itself and its peer (see
1615 * section 5.2.2 for a description of the Tie-Tags).
1617 * Verification Tag: Not explicit, but an INIT can not have a valid
1618 * verification tag, so we skip the check.
1621 * (endpoint, asoc, chunk)
1624 * (asoc, reply_msg, msg_up, timers, counters)
1626 * The return value is the disposition of the chunk.
1628 sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1629 const struct sctp_endpoint *ep,
1630 const struct sctp_association *asoc,
1631 const sctp_subtype_t type,
1633 sctp_cmd_seq_t *commands)
1635 /* Call helper to do the real work for both simulataneous and
1636 * duplicate INIT chunk handling.
1638 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1642 * Handle duplicated INIT messages. These are usually delayed
1645 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1646 * COOKIE-ECHOED and COOKIE-WAIT
1648 * Unless otherwise stated, upon reception of an unexpected INIT for
1649 * this association, the endpoint shall generate an INIT ACK with a
1650 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1651 * current Verification Tag and peer's Verification Tag into a reserved
1652 * place within the state cookie. We shall refer to these locations as
1653 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1654 * containing this INIT ACK MUST carry a Verification Tag value equal to
1655 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1656 * MUST contain a new Initiation Tag (randomly generated see Section
1657 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1658 * existing parameters of the association (e.g. number of outbound
1659 * streams) into the INIT ACK and cookie.
1661 * After sending out the INIT ACK, the endpoint shall take no further
1662 * actions, i.e., the existing association, including its current state,
1663 * and the corresponding TCB MUST NOT be changed.
1665 * Note: Only when a TCB exists and the association is not in a COOKIE-
1666 * WAIT state are the Tie-Tags populated. For a normal association INIT
1667 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1668 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1669 * State Cookie are populated as specified in section 5.2.1.
1671 * Verification Tag: Not specified, but an INIT has no way of knowing
1672 * what the verification tag could be, so we ignore it.
1675 * (endpoint, asoc, chunk)
1678 * (asoc, reply_msg, msg_up, timers, counters)
1680 * The return value is the disposition of the chunk.
1682 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1683 const struct sctp_endpoint *ep,
1684 const struct sctp_association *asoc,
1685 const sctp_subtype_t type,
1687 sctp_cmd_seq_t *commands)
1689 /* Call helper to do the real work for both simulataneous and
1690 * duplicate INIT chunk handling.
1692 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1697 * Unexpected INIT-ACK handler.
1700 * If an INIT ACK received by an endpoint in any state other than the
1701 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1702 * An unexpected INIT ACK usually indicates the processing of an old or
1703 * duplicated INIT chunk.
1705 sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1706 const struct sctp_endpoint *ep,
1707 const struct sctp_association *asoc,
1708 const sctp_subtype_t type,
1709 void *arg, sctp_cmd_seq_t *commands)
1711 /* Per the above section, we'll discard the chunk if we have an
1712 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1714 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
1715 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
1717 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
1720 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1723 * A) In this case, the peer may have restarted.
1725 static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1726 const struct sctp_endpoint *ep,
1727 const struct sctp_association *asoc,
1728 struct sctp_chunk *chunk,
1729 sctp_cmd_seq_t *commands,
1730 struct sctp_association *new_asoc)
1732 sctp_init_chunk_t *peer_init;
1733 struct sctp_ulpevent *ev;
1734 struct sctp_chunk *repl;
1735 struct sctp_chunk *err;
1736 sctp_disposition_t disposition;
1738 /* new_asoc is a brand-new association, so these are not yet
1739 * side effects--it is safe to run them here.
1741 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1743 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1747 /* Make sure no new addresses are being added during the
1748 * restart. Though this is a pretty complicated attack
1749 * since you'd have to get inside the cookie.
1751 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1752 return SCTP_DISPOSITION_CONSUME;
1755 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1756 * the peer has restarted (Action A), it MUST NOT setup a new
1757 * association but instead resend the SHUTDOWN ACK and send an ERROR
1758 * chunk with a "Cookie Received while Shutting Down" error cause to
1761 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1762 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1763 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1765 if (SCTP_DISPOSITION_NOMEM == disposition)
1768 err = sctp_make_op_error(asoc, chunk,
1769 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1772 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1775 return SCTP_DISPOSITION_CONSUME;
1778 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1779 * data. Consider the optional choice of resending of this data.
1781 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1782 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1783 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1784 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1786 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1787 * and ASCONF-ACK cache.
1789 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1790 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1791 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1793 repl = sctp_make_cookie_ack(new_asoc, chunk);
1797 /* Report association restart to upper layer. */
1798 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1799 new_asoc->c.sinit_num_ostreams,
1800 new_asoc->c.sinit_max_instreams,
1805 /* Update the content of current association. */
1806 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1807 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1808 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
1809 (sctp_sstate(asoc->base.sk, CLOSING) ||
1810 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1811 /* if were currently in SHUTDOWN_PENDING, but the socket
1812 * has been closed by user, don't transition to ESTABLISHED.
1813 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1815 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1816 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1817 SCTP_ST_CHUNK(0), NULL,
1820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1821 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1822 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1824 return SCTP_DISPOSITION_CONSUME;
1827 sctp_chunk_free(repl);
1829 return SCTP_DISPOSITION_NOMEM;
1832 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1835 * B) In this case, both sides may be attempting to start an association
1836 * at about the same time but the peer endpoint started its INIT
1837 * after responding to the local endpoint's INIT
1839 /* This case represents an initialization collision. */
1840 static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1841 const struct sctp_endpoint *ep,
1842 const struct sctp_association *asoc,
1843 struct sctp_chunk *chunk,
1844 sctp_cmd_seq_t *commands,
1845 struct sctp_association *new_asoc)
1847 sctp_init_chunk_t *peer_init;
1848 struct sctp_chunk *repl;
1850 /* new_asoc is a brand-new association, so these are not yet
1851 * side effects--it is safe to run them here.
1853 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1854 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1858 /* Update the content of current association. */
1859 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1860 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1861 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1862 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1863 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1865 repl = sctp_make_cookie_ack(new_asoc, chunk);
1869 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1871 /* RFC 2960 5.1 Normal Establishment of an Association
1873 * D) IMPLEMENTATION NOTE: An implementation may choose to
1874 * send the Communication Up notification to the SCTP user
1875 * upon reception of a valid COOKIE ECHO chunk.
1877 * Sadly, this needs to be implemented as a side-effect, because
1878 * we are not guaranteed to have set the association id of the real
1879 * association and so these notifications need to be delayed until
1880 * the association id is allocated.
1883 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1885 /* Sockets API Draft Section 5.3.1.6
1886 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1887 * delivers this notification to inform the application that of the
1888 * peers requested adaptation layer.
1890 * This also needs to be done as a side effect for the same reason as
1893 if (asoc->peer.adaptation_ind)
1894 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1896 return SCTP_DISPOSITION_CONSUME;
1899 return SCTP_DISPOSITION_NOMEM;
1902 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1905 * C) In this case, the local endpoint's cookie has arrived late.
1906 * Before it arrived, the local endpoint sent an INIT and received an
1907 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1908 * but a new tag of its own.
1910 /* This case represents an initialization collision. */
1911 static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1912 const struct sctp_endpoint *ep,
1913 const struct sctp_association *asoc,
1914 struct sctp_chunk *chunk,
1915 sctp_cmd_seq_t *commands,
1916 struct sctp_association *new_asoc)
1918 /* The cookie should be silently discarded.
1919 * The endpoint SHOULD NOT change states and should leave
1920 * any timers running.
1922 return SCTP_DISPOSITION_DISCARD;
1925 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1929 * D) When both local and remote tags match the endpoint should always
1930 * enter the ESTABLISHED state, if it has not already done so.
1932 /* This case represents an initialization collision. */
1933 static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1934 const struct sctp_endpoint *ep,
1935 const struct sctp_association *asoc,
1936 struct sctp_chunk *chunk,
1937 sctp_cmd_seq_t *commands,
1938 struct sctp_association *new_asoc)
1940 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1941 struct sctp_chunk *repl;
1943 /* Clarification from Implementor's Guide:
1944 * D) When both local and remote tags match the endpoint should
1945 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1946 * It should stop any cookie timer that may be running and send
1950 /* Don't accidentally move back into established state. */
1951 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1952 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1953 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1954 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1955 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1956 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1957 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1960 /* RFC 2960 5.1 Normal Establishment of an Association
1962 * D) IMPLEMENTATION NOTE: An implementation may choose
1963 * to send the Communication Up notification to the
1964 * SCTP user upon reception of a valid COOKIE
1967 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1969 asoc->c.sinit_num_ostreams,
1970 asoc->c.sinit_max_instreams,
1975 /* Sockets API Draft Section 5.3.1.6
1976 * When a peer sends a Adaptation Layer Indication parameter,
1977 * SCTP delivers this notification to inform the application
1978 * that of the peers requested adaptation layer.
1980 if (asoc->peer.adaptation_ind) {
1981 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1989 repl = sctp_make_cookie_ack(new_asoc, chunk);
1993 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1996 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1999 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2000 SCTP_ULPEVENT(ai_ev));
2002 return SCTP_DISPOSITION_CONSUME;
2006 sctp_ulpevent_free(ai_ev);
2008 sctp_ulpevent_free(ev);
2009 return SCTP_DISPOSITION_NOMEM;
2013 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2014 * chunk was retransmitted and then delayed in the network.
2016 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2018 * Verification Tag: None. Do cookie validation.
2021 * (endpoint, asoc, chunk)
2024 * (asoc, reply_msg, msg_up, timers, counters)
2026 * The return value is the disposition of the chunk.
2028 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
2029 const struct sctp_endpoint *ep,
2030 const struct sctp_association *asoc,
2031 const sctp_subtype_t type,
2033 sctp_cmd_seq_t *commands)
2035 sctp_disposition_t retval;
2036 struct sctp_chunk *chunk = arg;
2037 struct sctp_association *new_asoc;
2040 struct sctp_chunk *err_chk_p;
2042 /* Make sure that the chunk has a valid length from the protocol
2043 * perspective. In this case check to make sure we have at least
2044 * enough for the chunk header. Cookie length verification is
2047 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2048 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2051 /* "Decode" the chunk. We have no optional parameters so we
2052 * are in good shape.
2054 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2055 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2056 sizeof(sctp_chunkhdr_t)))
2059 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2060 * of a duplicate COOKIE ECHO match the Verification Tags of the
2061 * current association, consider the State Cookie valid even if
2062 * the lifespan is exceeded.
2064 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2068 * If the re-build failed, what is the proper error path
2071 * [We should abort the association. --piggy]
2074 /* FIXME: Several errors are possible. A bad cookie should
2075 * be silently discarded, but think about logging it too.
2078 case -SCTP_IERROR_NOMEM:
2081 case -SCTP_IERROR_STALE_COOKIE:
2082 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2084 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2085 case -SCTP_IERROR_BAD_SIG:
2087 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2091 /* Set temp so that it won't be added into hashtable */
2094 /* Compare the tie_tag in cookie with the verification tag of
2095 * current association.
2097 action = sctp_tietags_compare(new_asoc, asoc);
2100 case 'A': /* Association restart. */
2101 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2105 case 'B': /* Collision case B. */
2106 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2110 case 'C': /* Collision case C. */
2111 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2115 case 'D': /* Collision case D. */
2116 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2120 default: /* Discard packet for all others. */
2121 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2125 /* Delete the tempory new association. */
2126 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2127 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2129 /* Restore association pointer to provide SCTP command interpeter
2130 * with a valid context in case it needs to manipulate
2132 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2133 SCTP_ASOC((struct sctp_association *)asoc));
2138 return SCTP_DISPOSITION_NOMEM;
2142 * Process an ABORT. (SHUTDOWN-PENDING state)
2144 * See sctp_sf_do_9_1_abort().
2146 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2148 const struct sctp_endpoint *ep,
2149 const struct sctp_association *asoc,
2150 const sctp_subtype_t type,
2152 sctp_cmd_seq_t *commands)
2154 struct sctp_chunk *chunk = arg;
2156 if (!sctp_vtag_verify_either(chunk, asoc))
2157 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2159 /* Make sure that the ABORT chunk has a valid length.
2160 * Since this is an ABORT chunk, we have to discard it
2161 * because of the following text:
2162 * RFC 2960, Section 3.3.7
2163 * If an endpoint receives an ABORT with a format error or for an
2164 * association that doesn't exist, it MUST silently discard it.
2165 * Because the length is "invalid", we can't really discard just
2166 * as we do not know its true length. So, to be safe, discard the
2169 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2170 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2172 /* ADD-IP: Special case for ABORT chunks
2173 * F4) One special consideration is that ABORT Chunks arriving
2174 * destined to the IP address being deleted MUST be
2175 * ignored (see Section 5.3.1 for further details).
2177 if (SCTP_ADDR_DEL ==
2178 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2179 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2181 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2185 * Process an ABORT. (SHUTDOWN-SENT state)
2187 * See sctp_sf_do_9_1_abort().
2189 sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2190 const struct sctp_endpoint *ep,
2191 const struct sctp_association *asoc,
2192 const sctp_subtype_t type,
2194 sctp_cmd_seq_t *commands)
2196 struct sctp_chunk *chunk = arg;
2198 if (!sctp_vtag_verify_either(chunk, asoc))
2199 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2201 /* Make sure that the ABORT chunk has a valid length.
2202 * Since this is an ABORT chunk, we have to discard it
2203 * because of the following text:
2204 * RFC 2960, Section 3.3.7
2205 * If an endpoint receives an ABORT with a format error or for an
2206 * association that doesn't exist, it MUST silently discard it.
2207 * Because the length is "invalid", we can't really discard just
2208 * as we do not know its true length. So, to be safe, discard the
2211 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2212 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2214 /* ADD-IP: Special case for ABORT chunks
2215 * F4) One special consideration is that ABORT Chunks arriving
2216 * destined to the IP address being deleted MUST be
2217 * ignored (see Section 5.3.1 for further details).
2219 if (SCTP_ADDR_DEL ==
2220 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2221 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2223 /* Stop the T2-shutdown timer. */
2224 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2225 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2227 /* Stop the T5-shutdown guard timer. */
2228 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2229 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2231 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2235 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2237 * See sctp_sf_do_9_1_abort().
2239 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2241 const struct sctp_endpoint *ep,
2242 const struct sctp_association *asoc,
2243 const sctp_subtype_t type,
2245 sctp_cmd_seq_t *commands)
2247 /* The same T2 timer, so we should be able to use
2248 * common function with the SHUTDOWN-SENT state.
2250 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2254 * Handle an Error received in COOKIE_ECHOED state.
2256 * Only handle the error type of stale COOKIE Error, the other errors will
2260 * (endpoint, asoc, chunk)
2263 * (asoc, reply_msg, msg_up, timers, counters)
2265 * The return value is the disposition of the chunk.
2267 sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2268 const struct sctp_endpoint *ep,
2269 const struct sctp_association *asoc,
2270 const sctp_subtype_t type,
2272 sctp_cmd_seq_t *commands)
2274 struct sctp_chunk *chunk = arg;
2277 if (!sctp_vtag_verify(chunk, asoc))
2278 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2280 /* Make sure that the ERROR chunk has a valid length.
2281 * The parameter walking depends on this as well.
2283 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2284 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2287 /* Process the error here */
2288 /* FUTURE FIXME: When PR-SCTP related and other optional
2289 * parms are emitted, this will have to change to handle multiple
2292 sctp_walk_errors(err, chunk->chunk_hdr) {
2293 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2294 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2298 /* It is possible to have malformed error causes, and that
2299 * will cause us to end the walk early. However, since
2300 * we are discarding the packet, there should be no adverse
2303 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2307 * Handle a Stale COOKIE Error
2309 * Section: 5.2.6 Handle Stale COOKIE Error
2310 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2311 * one of the following three alternatives.
2313 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2314 * Preservative parameter requesting an extension to the lifetime of
2315 * the State Cookie. When calculating the time extension, an
2316 * implementation SHOULD use the RTT information measured based on the
2317 * previous COOKIE ECHO / ERROR exchange, and should add no more
2318 * than 1 second beyond the measured RTT, due to long State Cookie
2319 * lifetimes making the endpoint more subject to a replay attack.
2321 * Verification Tag: Not explicit, but safe to ignore.
2324 * (endpoint, asoc, chunk)
2327 * (asoc, reply_msg, msg_up, timers, counters)
2329 * The return value is the disposition of the chunk.
2331 static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2332 const struct sctp_endpoint *ep,
2333 const struct sctp_association *asoc,
2334 const sctp_subtype_t type,
2336 sctp_cmd_seq_t *commands)
2338 struct sctp_chunk *chunk = arg;
2340 sctp_cookie_preserve_param_t bht;
2342 struct sctp_chunk *reply;
2343 struct sctp_bind_addr *bp;
2344 int attempts = asoc->init_err_counter + 1;
2346 if (attempts > asoc->max_init_attempts) {
2347 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2348 SCTP_ERROR(ETIMEDOUT));
2349 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2350 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2351 return SCTP_DISPOSITION_DELETE_TCB;
2354 err = (sctp_errhdr_t *)(chunk->skb->data);
2356 /* When calculating the time extension, an implementation
2357 * SHOULD use the RTT information measured based on the
2358 * previous COOKIE ECHO / ERROR exchange, and should add no
2359 * more than 1 second beyond the measured RTT, due to long
2360 * State Cookie lifetimes making the endpoint more subject to
2362 * Measure of Staleness's unit is usec. (1/1000000 sec)
2363 * Suggested Cookie Life-span Increment's unit is msec.
2365 * In general, if you use the suggested cookie life, the value
2366 * found in the field of measure of staleness should be doubled
2367 * to give ample time to retransmit the new cookie and thus
2368 * yield a higher probability of success on the reattempt.
2370 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2371 stale = (stale * 2) / 1000;
2373 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2374 bht.param_hdr.length = htons(sizeof(bht));
2375 bht.lifespan_increment = htonl(stale);
2377 /* Build that new INIT chunk. */
2378 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2379 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2383 sctp_addto_chunk(reply, sizeof(bht), &bht);
2385 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2386 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2388 /* Stop pending T3-rtx and heartbeat timers */
2389 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2390 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2392 /* Delete non-primary peer ip addresses since we are transitioning
2393 * back to the COOKIE-WAIT state
2395 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2397 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2400 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2401 SCTP_TRANSPORT(asoc->peer.primary_path));
2403 /* Cast away the const modifier, as we want to just
2404 * rerun it through as a sideffect.
2406 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2408 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2409 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2410 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2411 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2412 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2413 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2415 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2417 return SCTP_DISPOSITION_CONSUME;
2420 return SCTP_DISPOSITION_NOMEM;
2427 * After checking the Verification Tag, the receiving endpoint shall
2428 * remove the association from its record, and shall report the
2429 * termination to its upper layer.
2431 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2432 * B) Rules for packet carrying ABORT:
2434 * - The endpoint shall always fill in the Verification Tag field of the
2435 * outbound packet with the destination endpoint's tag value if it
2438 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2439 * MUST follow the procedure described in Section 8.4.
2441 * - The receiver MUST accept the packet if the Verification Tag
2442 * matches either its own tag, OR the tag of its peer. Otherwise, the
2443 * receiver MUST silently discard the packet and take no further
2447 * (endpoint, asoc, chunk)
2450 * (asoc, reply_msg, msg_up, timers, counters)
2452 * The return value is the disposition of the chunk.
2454 sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2455 const struct sctp_endpoint *ep,
2456 const struct sctp_association *asoc,
2457 const sctp_subtype_t type,
2459 sctp_cmd_seq_t *commands)
2461 struct sctp_chunk *chunk = arg;
2463 if (!sctp_vtag_verify_either(chunk, asoc))
2464 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2466 /* Make sure that the ABORT chunk has a valid length.
2467 * Since this is an ABORT chunk, we have to discard it
2468 * because of the following text:
2469 * RFC 2960, Section 3.3.7
2470 * If an endpoint receives an ABORT with a format error or for an
2471 * association that doesn't exist, it MUST silently discard it.
2472 * Because the length is "invalid", we can't really discard just
2473 * as we do not know its true length. So, to be safe, discard the
2476 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2477 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2479 /* ADD-IP: Special case for ABORT chunks
2480 * F4) One special consideration is that ABORT Chunks arriving
2481 * destined to the IP address being deleted MUST be
2482 * ignored (see Section 5.3.1 for further details).
2484 if (SCTP_ADDR_DEL ==
2485 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2486 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2488 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2491 static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2492 const struct sctp_endpoint *ep,
2493 const struct sctp_association *asoc,
2494 const sctp_subtype_t type,
2496 sctp_cmd_seq_t *commands)
2498 struct sctp_chunk *chunk = arg;
2500 __be16 error = SCTP_ERROR_NO_ERROR;
2502 /* See if we have an error cause code in the chunk. */
2503 len = ntohs(chunk->chunk_hdr->length);
2504 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2507 sctp_walk_errors(err, chunk->chunk_hdr);
2508 if ((void *)err != (void *)chunk->chunk_end)
2509 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2511 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2514 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2515 /* ASSOC_FAILED will DELETE_TCB. */
2516 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2517 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2518 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2520 return SCTP_DISPOSITION_ABORT;
2524 * Process an ABORT. (COOKIE-WAIT state)
2526 * See sctp_sf_do_9_1_abort() above.
2528 sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2529 const struct sctp_endpoint *ep,
2530 const struct sctp_association *asoc,
2531 const sctp_subtype_t type,
2533 sctp_cmd_seq_t *commands)
2535 struct sctp_chunk *chunk = arg;
2537 __be16 error = SCTP_ERROR_NO_ERROR;
2539 if (!sctp_vtag_verify_either(chunk, asoc))
2540 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2542 /* Make sure that the ABORT chunk has a valid length.
2543 * Since this is an ABORT chunk, we have to discard it
2544 * because of the following text:
2545 * RFC 2960, Section 3.3.7
2546 * If an endpoint receives an ABORT with a format error or for an
2547 * association that doesn't exist, it MUST silently discard it.
2548 * Because the length is "invalid", we can't really discard just
2549 * as we do not know its true length. So, to be safe, discard the
2552 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2553 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2555 /* See if we have an error cause code in the chunk. */
2556 len = ntohs(chunk->chunk_hdr->length);
2557 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2558 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2560 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2565 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2567 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2568 const struct sctp_endpoint *ep,
2569 const struct sctp_association *asoc,
2570 const sctp_subtype_t type,
2572 sctp_cmd_seq_t *commands)
2574 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2576 (struct sctp_transport *)arg);
2580 * Process an ABORT. (COOKIE-ECHOED state)
2582 sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2583 const struct sctp_endpoint *ep,
2584 const struct sctp_association *asoc,
2585 const sctp_subtype_t type,
2587 sctp_cmd_seq_t *commands)
2589 /* There is a single T1 timer, so we should be able to use
2590 * common function with the COOKIE-WAIT state.
2592 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2596 * Stop T1 timer and abort association with "INIT failed".
2598 * This is common code called by several sctp_sf_*_abort() functions above.
2600 static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2601 sctp_cmd_seq_t *commands,
2602 __be16 error, int sk_err,
2603 const struct sctp_association *asoc,
2604 struct sctp_transport *transport)
2606 pr_debug("%s: ABORT received (INIT)\n", __func__);
2608 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2609 SCTP_STATE(SCTP_STATE_CLOSED));
2610 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2611 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2612 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2613 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2614 /* CMD_INIT_FAILED will DELETE_TCB. */
2615 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2618 return SCTP_DISPOSITION_ABORT;
2622 * sctp_sf_do_9_2_shut
2625 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2626 * - enter the SHUTDOWN-RECEIVED state,
2628 * - stop accepting new data from its SCTP user
2630 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2631 * that all its outstanding DATA chunks have been received by the
2634 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2635 * send a SHUTDOWN in response to a ULP request. And should discard
2636 * subsequent SHUTDOWN chunks.
2638 * If there are still outstanding DATA chunks left, the SHUTDOWN
2639 * receiver shall continue to follow normal data transmission
2640 * procedures defined in Section 6 until all outstanding DATA chunks
2641 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2642 * new data from its SCTP user.
2644 * Verification Tag: 8.5 Verification Tag [Normal verification]
2647 * (endpoint, asoc, chunk)
2650 * (asoc, reply_msg, msg_up, timers, counters)
2652 * The return value is the disposition of the chunk.
2654 sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2655 const struct sctp_endpoint *ep,
2656 const struct sctp_association *asoc,
2657 const sctp_subtype_t type,
2659 sctp_cmd_seq_t *commands)
2661 struct sctp_chunk *chunk = arg;
2662 sctp_shutdownhdr_t *sdh;
2663 sctp_disposition_t disposition;
2664 struct sctp_ulpevent *ev;
2667 if (!sctp_vtag_verify(chunk, asoc))
2668 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2670 /* Make sure that the SHUTDOWN chunk has a valid length. */
2671 if (!sctp_chunk_length_valid(chunk,
2672 sizeof(struct sctp_shutdown_chunk_t)))
2673 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2676 /* Convert the elaborate header. */
2677 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2678 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2679 chunk->subh.shutdown_hdr = sdh;
2680 ctsn = ntohl(sdh->cum_tsn_ack);
2682 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2683 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2684 asoc->ctsn_ack_point);
2686 return SCTP_DISPOSITION_DISCARD;
2689 /* If Cumulative TSN Ack beyond the max tsn currently
2690 * send, terminating the association and respond to the
2691 * sender with an ABORT.
2693 if (!TSN_lt(ctsn, asoc->next_tsn))
2694 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2696 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2697 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2698 * inform the application that it should cease sending data.
2700 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2702 disposition = SCTP_DISPOSITION_NOMEM;
2705 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2707 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2708 * - enter the SHUTDOWN-RECEIVED state,
2709 * - stop accepting new data from its SCTP user
2711 * [This is implicit in the new state.]
2713 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2714 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2715 disposition = SCTP_DISPOSITION_CONSUME;
2717 if (sctp_outq_is_empty(&asoc->outqueue)) {
2718 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2722 if (SCTP_DISPOSITION_NOMEM == disposition)
2725 /* - verify, by checking the Cumulative TSN Ack field of the
2726 * chunk, that all its outstanding DATA chunks have been
2727 * received by the SHUTDOWN sender.
2729 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2730 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2737 * sctp_sf_do_9_2_shut_ctsn
2739 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2740 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2741 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2742 * MUST be processed.
2744 sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2745 const struct sctp_endpoint *ep,
2746 const struct sctp_association *asoc,
2747 const sctp_subtype_t type,
2749 sctp_cmd_seq_t *commands)
2751 struct sctp_chunk *chunk = arg;
2752 sctp_shutdownhdr_t *sdh;
2755 if (!sctp_vtag_verify(chunk, asoc))
2756 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2758 /* Make sure that the SHUTDOWN chunk has a valid length. */
2759 if (!sctp_chunk_length_valid(chunk,
2760 sizeof(struct sctp_shutdown_chunk_t)))
2761 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2764 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2765 ctsn = ntohl(sdh->cum_tsn_ack);
2767 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2768 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2769 asoc->ctsn_ack_point);
2771 return SCTP_DISPOSITION_DISCARD;
2774 /* If Cumulative TSN Ack beyond the max tsn currently
2775 * send, terminating the association and respond to the
2776 * sender with an ABORT.
2778 if (!TSN_lt(ctsn, asoc->next_tsn))
2779 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2781 /* verify, by checking the Cumulative TSN Ack field of the
2782 * chunk, that all its outstanding DATA chunks have been
2783 * received by the SHUTDOWN sender.
2785 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2786 SCTP_BE32(sdh->cum_tsn_ack));
2788 return SCTP_DISPOSITION_CONSUME;
2792 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2793 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2794 * transport addresses (either in the IP addresses or in the INIT chunk)
2795 * that belong to this association, it should discard the INIT chunk and
2796 * retransmit the SHUTDOWN ACK chunk.
2798 sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2799 const struct sctp_endpoint *ep,
2800 const struct sctp_association *asoc,
2801 const sctp_subtype_t type,
2803 sctp_cmd_seq_t *commands)
2805 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2806 struct sctp_chunk *reply;
2808 /* Make sure that the chunk has a valid length */
2809 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2810 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2813 /* Since we are not going to really process this INIT, there
2814 * is no point in verifying chunk boundries. Just generate
2817 reply = sctp_make_shutdown_ack(asoc, chunk);
2821 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2822 * the T2-SHUTDOWN timer.
2824 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2826 /* and restart the T2-shutdown timer. */
2827 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2828 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2830 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2832 return SCTP_DISPOSITION_CONSUME;
2834 return SCTP_DISPOSITION_NOMEM;
2838 * sctp_sf_do_ecn_cwr
2840 * Section: Appendix A: Explicit Congestion Notification
2844 * RFC 2481 details a specific bit for a sender to send in the header of
2845 * its next outbound TCP segment to indicate to its peer that it has
2846 * reduced its congestion window. This is termed the CWR bit. For
2847 * SCTP the same indication is made by including the CWR chunk.
2848 * This chunk contains one data element, i.e. the TSN number that
2849 * was sent in the ECNE chunk. This element represents the lowest
2850 * TSN number in the datagram that was originally marked with the
2853 * Verification Tag: 8.5 Verification Tag [Normal verification]
2855 * (endpoint, asoc, chunk)
2858 * (asoc, reply_msg, msg_up, timers, counters)
2860 * The return value is the disposition of the chunk.
2862 sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2863 const struct sctp_endpoint *ep,
2864 const struct sctp_association *asoc,
2865 const sctp_subtype_t type,
2867 sctp_cmd_seq_t *commands)
2870 struct sctp_chunk *chunk = arg;
2873 if (!sctp_vtag_verify(chunk, asoc))
2874 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2876 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2877 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2880 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2881 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2883 lowest_tsn = ntohl(cwr->lowest_tsn);
2885 /* Does this CWR ack the last sent congestion notification? */
2886 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2887 /* Stop sending ECNE. */
2888 sctp_add_cmd_sf(commands,
2890 SCTP_U32(lowest_tsn));
2892 return SCTP_DISPOSITION_CONSUME;
2898 * Section: Appendix A: Explicit Congestion Notification
2902 * RFC 2481 details a specific bit for a receiver to send back in its
2903 * TCP acknowledgements to notify the sender of the Congestion
2904 * Experienced (CE) bit having arrived from the network. For SCTP this
2905 * same indication is made by including the ECNE chunk. This chunk
2906 * contains one data element, i.e. the lowest TSN associated with the IP
2907 * datagram marked with the CE bit.....
2909 * Verification Tag: 8.5 Verification Tag [Normal verification]
2911 * (endpoint, asoc, chunk)
2914 * (asoc, reply_msg, msg_up, timers, counters)
2916 * The return value is the disposition of the chunk.
2918 sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2919 const struct sctp_endpoint *ep,
2920 const struct sctp_association *asoc,
2921 const sctp_subtype_t type,
2923 sctp_cmd_seq_t *commands)
2925 sctp_ecnehdr_t *ecne;
2926 struct sctp_chunk *chunk = arg;
2928 if (!sctp_vtag_verify(chunk, asoc))
2929 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2931 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2932 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2935 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2936 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2938 /* If this is a newer ECNE than the last CWR packet we sent out */
2939 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2940 SCTP_U32(ntohl(ecne->lowest_tsn)));
2942 return SCTP_DISPOSITION_CONSUME;
2946 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2948 * The SCTP endpoint MUST always acknowledge the reception of each valid
2951 * The guidelines on delayed acknowledgement algorithm specified in
2952 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2953 * acknowledgement SHOULD be generated for at least every second packet
2954 * (not every second DATA chunk) received, and SHOULD be generated within
2955 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2956 * situations it may be beneficial for an SCTP transmitter to be more
2957 * conservative than the algorithms detailed in this document allow.
2958 * However, an SCTP transmitter MUST NOT be more aggressive than the
2959 * following algorithms allow.
2961 * A SCTP receiver MUST NOT generate more than one SACK for every
2962 * incoming packet, other than to update the offered window as the
2963 * receiving application consumes new data.
2965 * Verification Tag: 8.5 Verification Tag [Normal verification]
2968 * (endpoint, asoc, chunk)
2971 * (asoc, reply_msg, msg_up, timers, counters)
2973 * The return value is the disposition of the chunk.
2975 sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2976 const struct sctp_endpoint *ep,
2977 const struct sctp_association *asoc,
2978 const sctp_subtype_t type,
2980 sctp_cmd_seq_t *commands)
2982 struct sctp_chunk *chunk = arg;
2983 sctp_arg_t force = SCTP_NOFORCE();
2986 if (!sctp_vtag_verify(chunk, asoc)) {
2987 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2989 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2992 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2993 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2996 error = sctp_eat_data(asoc, chunk, commands);
2998 case SCTP_IERROR_NO_ERROR:
3000 case SCTP_IERROR_HIGH_TSN:
3001 case SCTP_IERROR_BAD_STREAM:
3002 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3003 goto discard_noforce;
3004 case SCTP_IERROR_DUP_TSN:
3005 case SCTP_IERROR_IGNORE_TSN:
3006 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3008 case SCTP_IERROR_NO_DATA:
3009 return SCTP_DISPOSITION_ABORT;
3010 case SCTP_IERROR_PROTO_VIOLATION:
3011 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3012 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3017 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
3018 force = SCTP_FORCE();
3020 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3021 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3022 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3025 /* If this is the last chunk in a packet, we need to count it
3026 * toward sack generation. Note that we need to SACK every
3027 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3028 * THEM. We elect to NOT generate SACK's if the chunk fails
3029 * the verification tag test.
3031 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3033 * The SCTP endpoint MUST always acknowledge the reception of
3034 * each valid DATA chunk.
3036 * The guidelines on delayed acknowledgement algorithm
3037 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3038 * Specifically, an acknowledgement SHOULD be generated for at
3039 * least every second packet (not every second DATA chunk)
3040 * received, and SHOULD be generated within 200 ms of the
3041 * arrival of any unacknowledged DATA chunk. In some
3042 * situations it may be beneficial for an SCTP transmitter to
3043 * be more conservative than the algorithms detailed in this
3044 * document allow. However, an SCTP transmitter MUST NOT be
3045 * more aggressive than the following algorithms allow.
3047 if (chunk->end_of_packet)
3048 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3050 return SCTP_DISPOSITION_CONSUME;
3053 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3055 * When a packet arrives with duplicate DATA chunk(s) and with
3056 * no new DATA chunk(s), the endpoint MUST immediately send a
3057 * SACK with no delay. If a packet arrives with duplicate
3058 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3059 * MAY immediately send a SACK. Normally receipt of duplicate
3060 * DATA chunks will occur when the original SACK chunk was lost
3061 * and the peer's RTO has expired. The duplicate TSN number(s)
3062 * SHOULD be reported in the SACK as duplicate.
3064 /* In our case, we split the MAY SACK advice up whether or not
3065 * the last chunk is a duplicate.'
3067 if (chunk->end_of_packet)
3068 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3069 return SCTP_DISPOSITION_DISCARD;
3072 if (chunk->end_of_packet)
3073 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3075 return SCTP_DISPOSITION_DISCARD;
3079 * sctp_sf_eat_data_fast_4_4
3082 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3083 * DATA chunks without delay.
3085 * Verification Tag: 8.5 Verification Tag [Normal verification]
3087 * (endpoint, asoc, chunk)
3090 * (asoc, reply_msg, msg_up, timers, counters)
3092 * The return value is the disposition of the chunk.
3094 sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3095 const struct sctp_endpoint *ep,
3096 const struct sctp_association *asoc,
3097 const sctp_subtype_t type,
3099 sctp_cmd_seq_t *commands)
3101 struct sctp_chunk *chunk = arg;
3104 if (!sctp_vtag_verify(chunk, asoc)) {
3105 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3107 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3110 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3111 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3114 error = sctp_eat_data(asoc, chunk, commands);
3116 case SCTP_IERROR_NO_ERROR:
3117 case SCTP_IERROR_HIGH_TSN:
3118 case SCTP_IERROR_DUP_TSN:
3119 case SCTP_IERROR_IGNORE_TSN:
3120 case SCTP_IERROR_BAD_STREAM:
3122 case SCTP_IERROR_NO_DATA:
3123 return SCTP_DISPOSITION_ABORT;
3124 case SCTP_IERROR_PROTO_VIOLATION:
3125 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3126 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3131 /* Go a head and force a SACK, since we are shutting down. */
3133 /* Implementor's Guide.
3135 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3136 * respond to each received packet containing one or more DATA chunk(s)
3137 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3139 if (chunk->end_of_packet) {
3140 /* We must delay the chunk creation since the cumulative
3141 * TSN has not been updated yet.
3143 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3144 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3145 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3146 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3149 return SCTP_DISPOSITION_CONSUME;
3153 * Section: 6.2 Processing a Received SACK
3154 * D) Any time a SACK arrives, the endpoint performs the following:
3156 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3157 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3158 * increasing, a SACK whose Cumulative TSN Ack is less than the
3159 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3161 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3162 * of bytes still outstanding after processing the Cumulative TSN Ack
3163 * and the Gap Ack Blocks.
3165 * iii) If the SACK is missing a TSN that was previously
3166 * acknowledged via a Gap Ack Block (e.g., the data receiver
3167 * reneged on the data), then mark the corresponding DATA chunk
3168 * as available for retransmit: Mark it as missing for fast
3169 * retransmit as described in Section 7.2.4 and if no retransmit
3170 * timer is running for the destination address to which the DATA
3171 * chunk was originally transmitted, then T3-rtx is started for
3172 * that destination address.
3174 * Verification Tag: 8.5 Verification Tag [Normal verification]
3177 * (endpoint, asoc, chunk)
3180 * (asoc, reply_msg, msg_up, timers, counters)
3182 * The return value is the disposition of the chunk.
3184 sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3185 const struct sctp_endpoint *ep,
3186 const struct sctp_association *asoc,
3187 const sctp_subtype_t type,
3189 sctp_cmd_seq_t *commands)
3191 struct sctp_chunk *chunk = arg;
3192 sctp_sackhdr_t *sackh;
3195 if (!sctp_vtag_verify(chunk, asoc))
3196 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3198 /* Make sure that the SACK chunk has a valid length. */
3199 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3200 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3203 /* Pull the SACK chunk from the data buffer */
3204 sackh = sctp_sm_pull_sack(chunk);
3205 /* Was this a bogus SACK? */
3207 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3208 chunk->subh.sack_hdr = sackh;
3209 ctsn = ntohl(sackh->cum_tsn_ack);
3211 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3212 * Ack Point, then drop the SACK. Since Cumulative TSN
3213 * Ack is monotonically increasing, a SACK whose
3214 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3215 * Point indicates an out-of-order SACK.
3217 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3218 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3219 asoc->ctsn_ack_point);
3221 return SCTP_DISPOSITION_DISCARD;
3224 /* If Cumulative TSN Ack beyond the max tsn currently
3225 * send, terminating the association and respond to the
3226 * sender with an ABORT.
3228 if (!TSN_lt(ctsn, asoc->next_tsn))
3229 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3231 /* Return this SACK for further processing. */
3232 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3234 /* Note: We do the rest of the work on the PROCESS_SACK
3237 return SCTP_DISPOSITION_CONSUME;
3241 * Generate an ABORT in response to a packet.
3243 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3245 * 8) The receiver should respond to the sender of the OOTB packet with
3246 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3247 * MUST fill in the Verification Tag field of the outbound packet
3248 * with the value found in the Verification Tag field of the OOTB
3249 * packet and set the T-bit in the Chunk Flags to indicate that the
3250 * Verification Tag is reflected. After sending this ABORT, the
3251 * receiver of the OOTB packet shall discard the OOTB packet and take
3252 * no further action.
3256 * The return value is the disposition of the chunk.
3258 static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3259 const struct sctp_endpoint *ep,
3260 const struct sctp_association *asoc,
3261 const sctp_subtype_t type,
3263 sctp_cmd_seq_t *commands)
3265 struct sctp_packet *packet = NULL;
3266 struct sctp_chunk *chunk = arg;
3267 struct sctp_chunk *abort;
3269 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3271 return SCTP_DISPOSITION_NOMEM;
3273 /* Make an ABORT. The T bit will be set if the asoc
3276 abort = sctp_make_abort(asoc, chunk, 0);
3278 sctp_ootb_pkt_free(packet);
3279 return SCTP_DISPOSITION_NOMEM;
3282 /* Reflect vtag if T-Bit is set */
3283 if (sctp_test_T_bit(abort))
3284 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3286 /* Set the skb to the belonging sock for accounting. */
3287 abort->skb->sk = ep->base.sk;
3289 sctp_packet_append_chunk(packet, abort);
3291 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3292 SCTP_PACKET(packet));
3294 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3296 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3297 return SCTP_DISPOSITION_CONSUME;
3301 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3302 * event as ULP notification for each cause included in the chunk.
3304 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3306 * The return value is the disposition of the chunk.
3308 sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3309 const struct sctp_endpoint *ep,
3310 const struct sctp_association *asoc,
3311 const sctp_subtype_t type,
3313 sctp_cmd_seq_t *commands)
3315 struct sctp_chunk *chunk = arg;
3318 if (!sctp_vtag_verify(chunk, asoc))
3319 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3321 /* Make sure that the ERROR chunk has a valid length. */
3322 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3323 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3325 sctp_walk_errors(err, chunk->chunk_hdr);
3326 if ((void *)err != (void *)chunk->chunk_end)
3327 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3328 (void *)err, commands);
3330 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3333 return SCTP_DISPOSITION_CONSUME;
3337 * Process an inbound SHUTDOWN ACK.
3340 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3341 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3342 * peer, and remove all record of the association.
3344 * The return value is the disposition.
3346 sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3347 const struct sctp_endpoint *ep,
3348 const struct sctp_association *asoc,
3349 const sctp_subtype_t type,
3351 sctp_cmd_seq_t *commands)
3353 struct sctp_chunk *chunk = arg;
3354 struct sctp_chunk *reply;
3355 struct sctp_ulpevent *ev;
3357 if (!sctp_vtag_verify(chunk, asoc))
3358 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3360 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3361 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3362 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3364 /* 10.2 H) SHUTDOWN COMPLETE notification
3366 * When SCTP completes the shutdown procedures (section 9.2) this
3367 * notification is passed to the upper layer.
3369 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3370 0, 0, 0, NULL, GFP_ATOMIC);
3374 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3375 reply = sctp_make_shutdown_complete(asoc, chunk);
3379 /* Do all the commands now (after allocation), so that we
3380 * have consistent state if memory allocation failes
3382 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3384 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3385 * stop the T2-shutdown timer,
3387 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3388 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3390 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3391 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3393 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3394 SCTP_STATE(SCTP_STATE_CLOSED));
3395 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3396 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3397 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3399 /* ...and remove all record of the association. */
3400 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3401 return SCTP_DISPOSITION_DELETE_TCB;
3404 sctp_ulpevent_free(ev);
3406 return SCTP_DISPOSITION_NOMEM;
3410 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3412 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3413 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3414 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3415 * packet must fill in the Verification Tag field of the outbound
3416 * packet with the Verification Tag received in the SHUTDOWN ACK and
3417 * set the T-bit in the Chunk Flags to indicate that the Verification
3420 * 8) The receiver should respond to the sender of the OOTB packet with
3421 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3422 * MUST fill in the Verification Tag field of the outbound packet
3423 * with the value found in the Verification Tag field of the OOTB
3424 * packet and set the T-bit in the Chunk Flags to indicate that the
3425 * Verification Tag is reflected. After sending this ABORT, the
3426 * receiver of the OOTB packet shall discard the OOTB packet and take
3427 * no further action.
3429 sctp_disposition_t sctp_sf_ootb(struct net *net,
3430 const struct sctp_endpoint *ep,
3431 const struct sctp_association *asoc,
3432 const sctp_subtype_t type,
3434 sctp_cmd_seq_t *commands)
3436 struct sctp_chunk *chunk = arg;
3437 struct sk_buff *skb = chunk->skb;
3438 sctp_chunkhdr_t *ch;
3441 int ootb_shut_ack = 0;
3442 int ootb_cookie_ack = 0;
3444 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3446 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3448 /* Report violation if the chunk is less then minimal */
3449 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3450 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3453 /* Report violation if chunk len overflows */
3454 ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
3455 if (ch_end > skb_tail_pointer(skb))
3456 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3459 /* Now that we know we at least have a chunk header,
3460 * do things that are type appropriate.
3462 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3465 /* RFC 2960, Section 3.3.7
3466 * Moreover, under any circumstances, an endpoint that
3467 * receives an ABORT MUST NOT respond to that ABORT by
3468 * sending an ABORT of its own.
3470 if (SCTP_CID_ABORT == ch->type)
3471 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3473 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3474 * or a COOKIE ACK the SCTP Packet should be silently
3478 if (SCTP_CID_COOKIE_ACK == ch->type)
3479 ootb_cookie_ack = 1;
3481 if (SCTP_CID_ERROR == ch->type) {
3482 sctp_walk_errors(err, ch) {
3483 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3484 ootb_cookie_ack = 1;
3490 ch = (sctp_chunkhdr_t *) ch_end;
3491 } while (ch_end < skb_tail_pointer(skb));
3494 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3495 else if (ootb_cookie_ack)
3496 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3498 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3502 * Handle an "Out of the blue" SHUTDOWN ACK.
3504 * Section: 8.4 5, sctpimpguide 2.41.
3506 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3507 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3508 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3509 * packet must fill in the Verification Tag field of the outbound
3510 * packet with the Verification Tag received in the SHUTDOWN ACK and
3511 * set the T-bit in the Chunk Flags to indicate that the Verification
3515 * (endpoint, asoc, type, arg, commands)
3518 * (sctp_disposition_t)
3520 * The return value is the disposition of the chunk.
3522 static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3523 const struct sctp_endpoint *ep,
3524 const struct sctp_association *asoc,
3525 const sctp_subtype_t type,
3527 sctp_cmd_seq_t *commands)
3529 struct sctp_packet *packet = NULL;
3530 struct sctp_chunk *chunk = arg;
3531 struct sctp_chunk *shut;
3533 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3535 return SCTP_DISPOSITION_NOMEM;
3537 /* Make an SHUTDOWN_COMPLETE.
3538 * The T bit will be set if the asoc is NULL.
3540 shut = sctp_make_shutdown_complete(asoc, chunk);
3542 sctp_ootb_pkt_free(packet);
3543 return SCTP_DISPOSITION_NOMEM;
3546 /* Reflect vtag if T-Bit is set */
3547 if (sctp_test_T_bit(shut))
3548 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3550 /* Set the skb to the belonging sock for accounting. */
3551 shut->skb->sk = ep->base.sk;
3553 sctp_packet_append_chunk(packet, shut);
3555 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3556 SCTP_PACKET(packet));
3558 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3560 /* If the chunk length is invalid, we don't want to process
3561 * the reset of the packet.
3563 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3564 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3566 /* We need to discard the rest of the packet to prevent
3567 * potential bomming attacks from additional bundled chunks.
3568 * This is documented in SCTP Threats ID.
3570 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3574 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3576 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3577 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3578 * procedures in section 8.4 SHOULD be followed, in other words it
3579 * should be treated as an Out Of The Blue packet.
3580 * [This means that we do NOT check the Verification Tag on these
3584 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3585 const struct sctp_endpoint *ep,
3586 const struct sctp_association *asoc,
3587 const sctp_subtype_t type,
3589 sctp_cmd_seq_t *commands)
3591 struct sctp_chunk *chunk = arg;
3593 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3594 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3595 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3598 /* Although we do have an association in this case, it corresponds
3599 * to a restarted association. So the packet is treated as an OOTB
3600 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3601 * called with a NULL association.
3603 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3605 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3608 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3609 sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3610 const struct sctp_endpoint *ep,
3611 const struct sctp_association *asoc,
3612 const sctp_subtype_t type, void *arg,
3613 sctp_cmd_seq_t *commands)
3615 struct sctp_chunk *chunk = arg;
3616 struct sctp_chunk *asconf_ack = NULL;
3617 struct sctp_paramhdr *err_param = NULL;
3618 sctp_addiphdr_t *hdr;
3621 if (!sctp_vtag_verify(chunk, asoc)) {
3622 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3624 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3627 /* ADD-IP: Section 4.1.1
3628 * This chunk MUST be sent in an authenticated way by using
3629 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3630 * is received unauthenticated it MUST be silently discarded as
3631 * described in [I-D.ietf-tsvwg-sctp-auth].
3633 if (!net->sctp.addip_noauth && !chunk->auth)
3634 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3636 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3637 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3638 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3641 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3642 serial = ntohl(hdr->serial);
3644 /* Verify the ASCONF chunk before processing it. */
3645 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
3646 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3647 (void *)err_param, commands);
3649 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3650 * the endpoint stored in a new association variable
3651 * 'Peer-Serial-Number'.
3653 if (serial == asoc->peer.addip_serial + 1) {
3654 /* If this is the first instance of ASCONF in the packet,
3655 * we can clean our old ASCONF-ACKs.
3657 if (!chunk->has_asconf)
3658 sctp_assoc_clean_asconf_ack_cache(asoc);
3660 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3661 * expected, process the ASCONF as described below and after
3662 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3663 * the response packet and cache a copy of it (in the event it
3664 * later needs to be retransmitted).
3666 * Essentially, do V1-V5.
3668 asconf_ack = sctp_process_asconf((struct sctp_association *)
3671 return SCTP_DISPOSITION_NOMEM;
3672 } else if (serial < asoc->peer.addip_serial + 1) {
3674 * If the value found in the Sequence Number is less than the
3675 * ('Peer- Sequence-Number' + 1), simply skip to the next
3676 * ASCONF, and include in the outbound response packet
3677 * any previously cached ASCONF-ACK response that was
3678 * sent and saved that matches the Sequence Number of the
3679 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3680 * Chunk exists. This will occur when an older ASCONF
3681 * arrives out of order. In such a case, the receiver
3682 * should skip the ASCONF Chunk and not include ASCONF-ACK
3683 * Chunk for that chunk.
3685 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3687 return SCTP_DISPOSITION_DISCARD;
3689 /* Reset the transport so that we select the correct one
3690 * this time around. This is to make sure that we don't
3691 * accidentally use a stale transport that's been removed.
3693 asconf_ack->transport = NULL;
3695 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3696 * it must be either a stale packet or from an attacker.
3698 return SCTP_DISPOSITION_DISCARD;
3701 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3702 * containing the ASCONF-ACK Chunks MUST be the source address of
3703 * the SCTP packet that held the ASCONF Chunks.
3705 * To do this properly, we'll set the destination address of the chunk
3706 * and at the transmit time, will try look up the transport to use.
3707 * Since ASCONFs may be bundled, the correct transport may not be
3708 * created until we process the entire packet, thus this workaround.
3710 asconf_ack->dest = chunk->source;
3711 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3712 if (asoc->new_transport) {
3713 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3714 ((struct sctp_association *)asoc)->new_transport = NULL;
3717 return SCTP_DISPOSITION_CONSUME;
3721 * ADDIP Section 4.3 General rules for address manipulation
3722 * When building TLV parameters for the ASCONF Chunk that will add or
3723 * delete IP addresses the D0 to D13 rules should be applied:
3725 sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3726 const struct sctp_endpoint *ep,
3727 const struct sctp_association *asoc,
3728 const sctp_subtype_t type, void *arg,
3729 sctp_cmd_seq_t *commands)
3731 struct sctp_chunk *asconf_ack = arg;
3732 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3733 struct sctp_chunk *abort;
3734 struct sctp_paramhdr *err_param = NULL;
3735 sctp_addiphdr_t *addip_hdr;
3736 __u32 sent_serial, rcvd_serial;
3738 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3739 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3741 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3744 /* ADD-IP, Section 4.1.2:
3745 * This chunk MUST be sent in an authenticated way by using
3746 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3747 * is received unauthenticated it MUST be silently discarded as
3748 * described in [I-D.ietf-tsvwg-sctp-auth].
3750 if (!net->sctp.addip_noauth && !asconf_ack->auth)
3751 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3753 /* Make sure that the ADDIP chunk has a valid length. */
3754 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3755 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3758 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3759 rcvd_serial = ntohl(addip_hdr->serial);
3761 /* Verify the ASCONF-ACK chunk before processing it. */
3762 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
3763 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3764 (void *)err_param, commands);
3767 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3768 sent_serial = ntohl(addip_hdr->serial);
3770 sent_serial = asoc->addip_serial - 1;
3773 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3774 * equal to the next serial number to be used but no ASCONF chunk is
3775 * outstanding the endpoint MUST ABORT the association. Note that a
3776 * sequence number is greater than if it is no more than 2^^31-1
3777 * larger than the current sequence number (using serial arithmetic).
3779 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3780 !(asoc->addip_last_asconf)) {
3781 abort = sctp_make_abort(asoc, asconf_ack,
3782 sizeof(sctp_errhdr_t));
3784 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3785 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3788 /* We are going to ABORT, so we might as well stop
3789 * processing the rest of the chunks in the packet.
3791 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3792 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3793 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3794 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3795 SCTP_ERROR(ECONNABORTED));
3796 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3797 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3798 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3799 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3800 return SCTP_DISPOSITION_ABORT;
3803 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3804 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3805 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3807 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3809 /* Successfully processed ASCONF_ACK. We can
3810 * release the next asconf if we have one.
3812 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3814 return SCTP_DISPOSITION_CONSUME;
3817 abort = sctp_make_abort(asoc, asconf_ack,
3818 sizeof(sctp_errhdr_t));
3820 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3821 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3824 /* We are going to ABORT, so we might as well stop
3825 * processing the rest of the chunks in the packet.
3827 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3828 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3829 SCTP_ERROR(ECONNABORTED));
3830 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3831 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3832 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3833 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3834 return SCTP_DISPOSITION_ABORT;
3837 return SCTP_DISPOSITION_DISCARD;
3840 /* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
3841 sctp_disposition_t sctp_sf_do_reconf(struct net *net,
3842 const struct sctp_endpoint *ep,
3843 const struct sctp_association *asoc,
3844 const sctp_subtype_t type, void *arg,
3845 sctp_cmd_seq_t *commands)
3847 struct sctp_paramhdr *err_param = NULL;
3848 struct sctp_chunk *chunk = arg;
3849 struct sctp_reconf_chunk *hdr;
3850 union sctp_params param;
3852 if (!sctp_vtag_verify(chunk, asoc)) {
3853 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3855 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3858 /* Make sure that the RECONF chunk has a valid length. */
3859 if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
3860 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3863 if (!sctp_verify_reconf(asoc, chunk, &err_param))
3864 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3865 (void *)err_param, commands);
3867 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3868 sctp_walk_params(param, hdr, params) {
3869 struct sctp_chunk *reply = NULL;
3870 struct sctp_ulpevent *ev = NULL;
3872 if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
3873 reply = sctp_process_strreset_outreq(
3874 (struct sctp_association *)asoc, param, &ev);
3875 else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
3876 reply = sctp_process_strreset_inreq(
3877 (struct sctp_association *)asoc, param, &ev);
3878 else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
3879 reply = sctp_process_strreset_tsnreq(
3880 (struct sctp_association *)asoc, param, &ev);
3881 else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
3882 reply = sctp_process_strreset_addstrm_out(
3883 (struct sctp_association *)asoc, param, &ev);
3884 else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
3885 reply = sctp_process_strreset_addstrm_in(
3886 (struct sctp_association *)asoc, param, &ev);
3887 else if (param.p->type == SCTP_PARAM_RESET_RESPONSE)
3888 reply = sctp_process_strreset_resp(
3889 (struct sctp_association *)asoc, param, &ev);
3892 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3896 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3900 return SCTP_DISPOSITION_CONSUME;
3904 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3906 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3907 * its cumulative TSN point to the value carried in the FORWARD TSN
3908 * chunk, and then MUST further advance its cumulative TSN point locally
3910 * After the above processing, the data receiver MUST stop reporting any
3911 * missing TSNs earlier than or equal to the new cumulative TSN point.
3913 * Verification Tag: 8.5 Verification Tag [Normal verification]
3915 * The return value is the disposition of the chunk.
3917 sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3918 const struct sctp_endpoint *ep,
3919 const struct sctp_association *asoc,
3920 const sctp_subtype_t type,
3922 sctp_cmd_seq_t *commands)
3924 struct sctp_chunk *chunk = arg;
3925 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3926 struct sctp_fwdtsn_skip *skip;
3930 if (!sctp_vtag_verify(chunk, asoc)) {
3931 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3933 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3936 if (!asoc->peer.prsctp_capable)
3937 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
3939 /* Make sure that the FORWARD_TSN chunk has valid length. */
3940 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3941 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3944 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3945 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3946 len = ntohs(chunk->chunk_hdr->length);
3947 len -= sizeof(struct sctp_chunkhdr);
3948 skb_pull(chunk->skb, len);
3950 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3951 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3953 /* The TSN is too high--silently discard the chunk and count on it
3954 * getting retransmitted later.
3956 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3957 goto discard_noforce;
3959 /* Silently discard the chunk if stream-id is not valid */
3960 sctp_walk_fwdtsn(skip, chunk) {
3961 if (ntohs(skip->stream) >= asoc->stream->incnt)
3962 goto discard_noforce;
3965 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3966 if (len > sizeof(struct sctp_fwdtsn_hdr))
3967 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3970 /* Count this as receiving DATA. */
3971 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3972 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3973 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3976 /* FIXME: For now send a SACK, but DATA processing may
3979 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3981 return SCTP_DISPOSITION_CONSUME;
3984 return SCTP_DISPOSITION_DISCARD;
3987 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3989 const struct sctp_endpoint *ep,
3990 const struct sctp_association *asoc,
3991 const sctp_subtype_t type,
3993 sctp_cmd_seq_t *commands)
3995 struct sctp_chunk *chunk = arg;
3996 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3997 struct sctp_fwdtsn_skip *skip;
4001 if (!sctp_vtag_verify(chunk, asoc)) {
4002 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4004 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4007 if (!asoc->peer.prsctp_capable)
4008 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4010 /* Make sure that the FORWARD_TSN chunk has a valid length. */
4011 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
4012 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4015 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4016 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4017 len = ntohs(chunk->chunk_hdr->length);
4018 len -= sizeof(struct sctp_chunkhdr);
4019 skb_pull(chunk->skb, len);
4021 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
4022 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
4024 /* The TSN is too high--silently discard the chunk and count on it
4025 * getting retransmitted later.
4027 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4030 /* Silently discard the chunk if stream-id is not valid */
4031 sctp_walk_fwdtsn(skip, chunk) {
4032 if (ntohs(skip->stream) >= asoc->stream->incnt)
4036 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4037 if (len > sizeof(struct sctp_fwdtsn_hdr))
4038 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
4041 /* Go a head and force a SACK, since we are shutting down. */
4043 /* Implementor's Guide.
4045 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
4046 * respond to each received packet containing one or more DATA chunk(s)
4047 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
4049 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
4050 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4051 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4052 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4054 return SCTP_DISPOSITION_CONSUME;
4058 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
4060 * The receiver MUST use the HMAC algorithm indicated in the HMAC
4061 * Identifier field. If this algorithm was not specified by the
4062 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
4063 * during association setup, the AUTH chunk and all chunks after it MUST
4064 * be discarded and an ERROR chunk SHOULD be sent with the error cause
4065 * defined in Section 4.1.
4067 * If an endpoint with no shared key receives a Shared Key Identifier
4068 * other than 0, it MUST silently discard all authenticated chunks. If
4069 * the endpoint has at least one endpoint pair shared key for the peer,
4070 * it MUST use the key specified by the Shared Key Identifier if a
4071 * key has been configured for that Shared Key Identifier. If no
4072 * endpoint pair shared key has been configured for that Shared Key
4073 * Identifier, all authenticated chunks MUST be silently discarded.
4075 * Verification Tag: 8.5 Verification Tag [Normal verification]
4077 * The return value is the disposition of the chunk.
4079 static sctp_ierror_t sctp_sf_authenticate(struct net *net,
4080 const struct sctp_endpoint *ep,
4081 const struct sctp_association *asoc,
4082 const sctp_subtype_t type,
4083 struct sctp_chunk *chunk)
4085 struct sctp_authhdr *auth_hdr;
4086 struct sctp_hmac *hmac;
4087 unsigned int sig_len;
4092 /* Pull in the auth header, so we can do some more verification */
4093 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4094 chunk->subh.auth_hdr = auth_hdr;
4095 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4097 /* Make sure that we support the HMAC algorithm from the auth
4100 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4101 return SCTP_IERROR_AUTH_BAD_HMAC;
4103 /* Make sure that the provided shared key identifier has been
4106 key_id = ntohs(auth_hdr->shkey_id);
4107 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4108 return SCTP_IERROR_AUTH_BAD_KEYID;
4111 /* Make sure that the length of the signature matches what
4114 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4115 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4116 if (sig_len != hmac->hmac_len)
4117 return SCTP_IERROR_PROTO_VIOLATION;
4119 /* Now that we've done validation checks, we can compute and
4120 * verify the hmac. The steps involved are:
4121 * 1. Save the digest from the chunk.
4122 * 2. Zero out the digest in the chunk.
4123 * 3. Compute the new digest
4124 * 4. Compare saved and new digests.
4126 digest = auth_hdr->hmac;
4127 skb_pull(chunk->skb, sig_len);
4129 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4133 memset(digest, 0, sig_len);
4135 sctp_auth_calculate_hmac(asoc, chunk->skb,
4136 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4139 /* Discard the packet if the digests do not match */
4140 if (memcmp(save_digest, digest, sig_len)) {
4142 return SCTP_IERROR_BAD_SIG;
4148 return SCTP_IERROR_NO_ERROR;
4150 return SCTP_IERROR_NOMEM;
4153 sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4154 const struct sctp_endpoint *ep,
4155 const struct sctp_association *asoc,
4156 const sctp_subtype_t type,
4158 sctp_cmd_seq_t *commands)
4160 struct sctp_authhdr *auth_hdr;
4161 struct sctp_chunk *chunk = arg;
4162 struct sctp_chunk *err_chunk;
4163 sctp_ierror_t error;
4165 /* Make sure that the peer has AUTH capable */
4166 if (!asoc->peer.auth_capable)
4167 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4169 if (!sctp_vtag_verify(chunk, asoc)) {
4170 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4172 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4175 /* Make sure that the AUTH chunk has valid length. */
4176 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4177 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4180 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4181 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
4183 case SCTP_IERROR_AUTH_BAD_HMAC:
4184 /* Generate the ERROR chunk and discard the rest
4187 err_chunk = sctp_make_op_error(asoc, chunk,
4188 SCTP_ERROR_UNSUP_HMAC,
4192 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4193 SCTP_CHUNK(err_chunk));
4196 case SCTP_IERROR_AUTH_BAD_KEYID:
4197 case SCTP_IERROR_BAD_SIG:
4198 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4200 case SCTP_IERROR_PROTO_VIOLATION:
4201 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4204 case SCTP_IERROR_NOMEM:
4205 return SCTP_DISPOSITION_NOMEM;
4207 default: /* Prevent gcc warnings */
4211 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4212 struct sctp_ulpevent *ev;
4214 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4215 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4220 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4224 return SCTP_DISPOSITION_CONSUME;
4228 * Process an unknown chunk.
4230 * Section: 3.2. Also, 2.1 in the implementor's guide.
4232 * Chunk Types are encoded such that the highest-order two bits specify
4233 * the action that must be taken if the processing endpoint does not
4234 * recognize the Chunk Type.
4236 * 00 - Stop processing this SCTP packet and discard it, do not process
4237 * any further chunks within it.
4239 * 01 - Stop processing this SCTP packet and discard it, do not process
4240 * any further chunks within it, and report the unrecognized
4241 * chunk in an 'Unrecognized Chunk Type'.
4243 * 10 - Skip this chunk and continue processing.
4245 * 11 - Skip this chunk and continue processing, but report in an ERROR
4246 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4248 * The return value is the disposition of the chunk.
4250 sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4251 const struct sctp_endpoint *ep,
4252 const struct sctp_association *asoc,
4253 const sctp_subtype_t type,
4255 sctp_cmd_seq_t *commands)
4257 struct sctp_chunk *unk_chunk = arg;
4258 struct sctp_chunk *err_chunk;
4259 sctp_chunkhdr_t *hdr;
4261 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4263 if (!sctp_vtag_verify(unk_chunk, asoc))
4264 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4266 /* Make sure that the chunk has a valid length.
4267 * Since we don't know the chunk type, we use a general
4268 * chunkhdr structure to make a comparison.
4270 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4271 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4274 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4275 case SCTP_CID_ACTION_DISCARD:
4276 /* Discard the packet. */
4277 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4278 case SCTP_CID_ACTION_DISCARD_ERR:
4279 /* Generate an ERROR chunk as response. */
4280 hdr = unk_chunk->chunk_hdr;
4281 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4282 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4283 SCTP_PAD4(ntohs(hdr->length)),
4286 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4287 SCTP_CHUNK(err_chunk));
4290 /* Discard the packet. */
4291 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4292 return SCTP_DISPOSITION_CONSUME;
4293 case SCTP_CID_ACTION_SKIP:
4294 /* Skip the chunk. */
4295 return SCTP_DISPOSITION_DISCARD;
4296 case SCTP_CID_ACTION_SKIP_ERR:
4297 /* Generate an ERROR chunk as response. */
4298 hdr = unk_chunk->chunk_hdr;
4299 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4300 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4301 SCTP_PAD4(ntohs(hdr->length)),
4304 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4305 SCTP_CHUNK(err_chunk));
4307 /* Skip the chunk. */
4308 return SCTP_DISPOSITION_CONSUME;
4313 return SCTP_DISPOSITION_DISCARD;
4317 * Discard the chunk.
4319 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4320 * [Too numerous to mention...]
4321 * Verification Tag: No verification needed.
4323 * (endpoint, asoc, chunk)
4326 * (asoc, reply_msg, msg_up, timers, counters)
4328 * The return value is the disposition of the chunk.
4330 sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4331 const struct sctp_endpoint *ep,
4332 const struct sctp_association *asoc,
4333 const sctp_subtype_t type,
4335 sctp_cmd_seq_t *commands)
4337 struct sctp_chunk *chunk = arg;
4339 /* Make sure that the chunk has a valid length.
4340 * Since we don't know the chunk type, we use a general
4341 * chunkhdr structure to make a comparison.
4343 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4344 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4347 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4349 return SCTP_DISPOSITION_DISCARD;
4353 * Discard the whole packet.
4357 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4358 * silently discard the OOTB packet and take no further action.
4360 * Verification Tag: No verification necessary
4363 * (endpoint, asoc, chunk)
4366 * (asoc, reply_msg, msg_up, timers, counters)
4368 * The return value is the disposition of the chunk.
4370 sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4371 const struct sctp_endpoint *ep,
4372 const struct sctp_association *asoc,
4373 const sctp_subtype_t type,
4375 sctp_cmd_seq_t *commands)
4377 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4378 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4380 return SCTP_DISPOSITION_CONSUME;
4385 * The other end is violating protocol.
4387 * Section: Not specified
4388 * Verification Tag: Not specified
4390 * (endpoint, asoc, chunk)
4393 * (asoc, reply_msg, msg_up, timers, counters)
4395 * We simply tag the chunk as a violation. The state machine will log
4396 * the violation and continue.
4398 sctp_disposition_t sctp_sf_violation(struct net *net,
4399 const struct sctp_endpoint *ep,
4400 const struct sctp_association *asoc,
4401 const sctp_subtype_t type,
4403 sctp_cmd_seq_t *commands)
4405 struct sctp_chunk *chunk = arg;
4407 /* Make sure that the chunk has a valid length. */
4408 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4409 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4412 return SCTP_DISPOSITION_VIOLATION;
4416 * Common function to handle a protocol violation.
4418 static sctp_disposition_t sctp_sf_abort_violation(
4420 const struct sctp_endpoint *ep,
4421 const struct sctp_association *asoc,
4423 sctp_cmd_seq_t *commands,
4424 const __u8 *payload,
4425 const size_t paylen)
4427 struct sctp_packet *packet = NULL;
4428 struct sctp_chunk *chunk = arg;
4429 struct sctp_chunk *abort = NULL;
4431 /* SCTP-AUTH, Section 6.3:
4432 * It should be noted that if the receiver wants to tear
4433 * down an association in an authenticated way only, the
4434 * handling of malformed packets should not result in
4435 * tearing down the association.
4437 * This means that if we only want to abort associations
4438 * in an authenticated way (i.e AUTH+ABORT), then we
4439 * can't destroy this association just because the packet
4442 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4445 /* Make the abort chunk. */
4446 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4451 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4452 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4453 !asoc->peer.i.init_tag) {
4454 sctp_initack_chunk_t *initack;
4456 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4457 if (!sctp_chunk_length_valid(chunk,
4458 sizeof(sctp_initack_chunk_t)))
4459 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4461 unsigned int inittag;
4463 inittag = ntohl(initack->init_hdr.init_tag);
4464 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4469 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4470 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4472 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4473 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4474 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4475 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4476 SCTP_ERROR(ECONNREFUSED));
4477 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4478 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4480 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4481 SCTP_ERROR(ECONNABORTED));
4482 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4483 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4484 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4487 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4492 if (sctp_test_T_bit(abort))
4493 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4495 abort->skb->sk = ep->base.sk;
4497 sctp_packet_append_chunk(packet, abort);
4499 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4500 SCTP_PACKET(packet));
4502 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4505 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4508 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4509 return SCTP_DISPOSITION_ABORT;
4512 sctp_chunk_free(abort);
4514 return SCTP_DISPOSITION_NOMEM;
4518 * Handle a protocol violation when the chunk length is invalid.
4519 * "Invalid" length is identified as smaller than the minimal length a
4520 * given chunk can be. For example, a SACK chunk has invalid length
4521 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4523 * We inform the other end by sending an ABORT with a Protocol Violation
4526 * Section: Not specified
4527 * Verification Tag: Nothing to do
4529 * (endpoint, asoc, chunk)
4532 * (reply_msg, msg_up, counters)
4534 * Generate an ABORT chunk and terminate the association.
4536 static sctp_disposition_t sctp_sf_violation_chunklen(
4538 const struct sctp_endpoint *ep,
4539 const struct sctp_association *asoc,
4540 const sctp_subtype_t type,
4542 sctp_cmd_seq_t *commands)
4544 static const char err_str[] = "The following chunk had invalid length:";
4546 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4551 * Handle a protocol violation when the parameter length is invalid.
4552 * If the length is smaller than the minimum length of a given parameter,
4553 * or accumulated length in multi parameters exceeds the end of the chunk,
4554 * the length is considered as invalid.
4556 static sctp_disposition_t sctp_sf_violation_paramlen(
4558 const struct sctp_endpoint *ep,
4559 const struct sctp_association *asoc,
4560 const sctp_subtype_t type,
4561 void *arg, void *ext,
4562 sctp_cmd_seq_t *commands)
4564 struct sctp_chunk *chunk = arg;
4565 struct sctp_paramhdr *param = ext;
4566 struct sctp_chunk *abort = NULL;
4568 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4571 /* Make the abort chunk. */
4572 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4576 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4577 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4579 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4580 SCTP_ERROR(ECONNABORTED));
4581 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4582 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4583 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4584 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4587 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4588 return SCTP_DISPOSITION_ABORT;
4590 return SCTP_DISPOSITION_NOMEM;
4593 /* Handle a protocol violation when the peer trying to advance the
4594 * cumulative tsn ack to a point beyond the max tsn currently sent.
4596 * We inform the other end by sending an ABORT with a Protocol Violation
4599 static sctp_disposition_t sctp_sf_violation_ctsn(
4601 const struct sctp_endpoint *ep,
4602 const struct sctp_association *asoc,
4603 const sctp_subtype_t type,
4605 sctp_cmd_seq_t *commands)
4607 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4609 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4613 /* Handle protocol violation of an invalid chunk bundling. For example,
4614 * when we have an association and we receive bundled INIT-ACK, or
4615 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4616 * statement from the specs. Additionally, there might be an attacker
4617 * on the path and we may not want to continue this communication.
4619 static sctp_disposition_t sctp_sf_violation_chunk(
4621 const struct sctp_endpoint *ep,
4622 const struct sctp_association *asoc,
4623 const sctp_subtype_t type,
4625 sctp_cmd_seq_t *commands)
4627 static const char err_str[] = "The following chunk violates protocol:";
4630 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
4632 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4635 /***************************************************************************
4636 * These are the state functions for handling primitive (Section 10) events.
4637 ***************************************************************************/
4639 * sctp_sf_do_prm_asoc
4641 * Section: 10.1 ULP-to-SCTP
4644 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4645 * outbound stream count)
4646 * -> association id [,destination transport addr list] [,outbound stream
4649 * This primitive allows the upper layer to initiate an association to a
4650 * specific peer endpoint.
4652 * The peer endpoint shall be specified by one of the transport addresses
4653 * which defines the endpoint (see Section 1.4). If the local SCTP
4654 * instance has not been initialized, the ASSOCIATE is considered an
4656 * [This is not relevant for the kernel implementation since we do all
4657 * initialization at boot time. It we hadn't initialized we wouldn't
4658 * get anywhere near this code.]
4660 * An association id, which is a local handle to the SCTP association,
4661 * will be returned on successful establishment of the association. If
4662 * SCTP is not able to open an SCTP association with the peer endpoint,
4663 * an error is returned.
4664 * [In the kernel implementation, the struct sctp_association needs to
4665 * be created BEFORE causing this primitive to run.]
4667 * Other association parameters may be returned, including the
4668 * complete destination transport addresses of the peer as well as the
4669 * outbound stream count of the local endpoint. One of the transport
4670 * address from the returned destination addresses will be selected by
4671 * the local endpoint as default primary path for sending SCTP packets
4672 * to this peer. The returned "destination transport addr list" can
4673 * be used by the ULP to change the default primary path or to force
4674 * sending a packet to a specific transport address. [All of this
4675 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4678 * Mandatory attributes:
4680 * o local SCTP instance name - obtained from the INITIALIZE operation.
4681 * [This is the argument asoc.]
4682 * o destination transport addr - specified as one of the transport
4683 * addresses of the peer endpoint with which the association is to be
4685 * [This is asoc->peer.active_path.]
4686 * o outbound stream count - the number of outbound streams the ULP
4687 * would like to open towards this peer endpoint.
4688 * [BUG: This is not currently implemented.]
4689 * Optional attributes:
4693 * The return value is a disposition.
4695 sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4696 const struct sctp_endpoint *ep,
4697 const struct sctp_association *asoc,
4698 const sctp_subtype_t type,
4700 sctp_cmd_seq_t *commands)
4702 struct sctp_chunk *repl;
4703 struct sctp_association *my_asoc;
4705 /* The comment below says that we enter COOKIE-WAIT AFTER
4706 * sending the INIT, but that doesn't actually work in our
4709 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4710 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4712 /* RFC 2960 5.1 Normal Establishment of an Association
4714 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4715 * must provide its Verification Tag (Tag_A) in the Initiate
4716 * Tag field. Tag_A SHOULD be a random number in the range of
4717 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4720 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4724 /* Choose transport for INIT. */
4725 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4728 /* Cast away the const modifier, as we want to just
4729 * rerun it through as a sideffect.
4731 my_asoc = (struct sctp_association *)asoc;
4732 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4734 /* After sending the INIT, "A" starts the T1-init timer and
4735 * enters the COOKIE-WAIT state.
4737 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4738 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4739 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4740 return SCTP_DISPOSITION_CONSUME;
4743 return SCTP_DISPOSITION_NOMEM;
4747 * Process the SEND primitive.
4749 * Section: 10.1 ULP-to-SCTP
4752 * Format: SEND(association id, buffer address, byte count [,context]
4753 * [,stream id] [,life time] [,destination transport address]
4754 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4757 * This is the main method to send user data via SCTP.
4759 * Mandatory attributes:
4761 * o association id - local handle to the SCTP association
4763 * o buffer address - the location where the user message to be
4764 * transmitted is stored;
4766 * o byte count - The size of the user data in number of bytes;
4768 * Optional attributes:
4770 * o context - an optional 32 bit integer that will be carried in the
4771 * sending failure notification to the ULP if the transportation of
4772 * this User Message fails.
4774 * o stream id - to indicate which stream to send the data on. If not
4775 * specified, stream 0 will be used.
4777 * o life time - specifies the life time of the user data. The user data
4778 * will not be sent by SCTP after the life time expires. This
4779 * parameter can be used to avoid efforts to transmit stale
4780 * user messages. SCTP notifies the ULP if the data cannot be
4781 * initiated to transport (i.e. sent to the destination via SCTP's
4782 * send primitive) within the life time variable. However, the
4783 * user data will be transmitted if SCTP has attempted to transmit a
4784 * chunk before the life time expired.
4786 * o destination transport address - specified as one of the destination
4787 * transport addresses of the peer endpoint to which this packet
4788 * should be sent. Whenever possible, SCTP should use this destination
4789 * transport address for sending the packets, instead of the current
4792 * o unorder flag - this flag, if present, indicates that the user
4793 * would like the data delivered in an unordered fashion to the peer
4794 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4797 * o no-bundle flag - instructs SCTP not to bundle this user data with
4798 * other outbound DATA chunks. SCTP MAY still bundle even when
4799 * this flag is present, when faced with network congestion.
4801 * o payload protocol-id - A 32 bit unsigned integer that is to be
4802 * passed to the peer indicating the type of payload protocol data
4803 * being transmitted. This value is passed as opaque data by SCTP.
4805 * The return value is the disposition.
4807 sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4808 const struct sctp_endpoint *ep,
4809 const struct sctp_association *asoc,
4810 const sctp_subtype_t type,
4812 sctp_cmd_seq_t *commands)
4814 struct sctp_datamsg *msg = arg;
4816 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4817 return SCTP_DISPOSITION_CONSUME;
4821 * Process the SHUTDOWN primitive.
4826 * Format: SHUTDOWN(association id)
4829 * Gracefully closes an association. Any locally queued user data
4830 * will be delivered to the peer. The association will be terminated only
4831 * after the peer acknowledges all the SCTP packets sent. A success code
4832 * will be returned on successful termination of the association. If
4833 * attempting to terminate the association results in a failure, an error
4834 * code shall be returned.
4836 * Mandatory attributes:
4838 * o association id - local handle to the SCTP association
4840 * Optional attributes:
4844 * The return value is the disposition.
4846 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4848 const struct sctp_endpoint *ep,
4849 const struct sctp_association *asoc,
4850 const sctp_subtype_t type,
4852 sctp_cmd_seq_t *commands)
4856 /* From 9.2 Shutdown of an Association
4857 * Upon receipt of the SHUTDOWN primitive from its upper
4858 * layer, the endpoint enters SHUTDOWN-PENDING state and
4859 * remains there until all outstanding data has been
4860 * acknowledged by its peer. The endpoint accepts no new data
4861 * from its upper layer, but retransmits data to the far end
4862 * if necessary to fill gaps.
4864 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4865 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4867 disposition = SCTP_DISPOSITION_CONSUME;
4868 if (sctp_outq_is_empty(&asoc->outqueue)) {
4869 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
4876 * Process the ABORT primitive.
4881 * Format: Abort(association id [, cause code])
4884 * Ungracefully closes an association. Any locally queued user data
4885 * will be discarded and an ABORT chunk is sent to the peer. A success code
4886 * will be returned on successful abortion of the association. If
4887 * attempting to abort the association results in a failure, an error
4888 * code shall be returned.
4890 * Mandatory attributes:
4892 * o association id - local handle to the SCTP association
4894 * Optional attributes:
4896 * o cause code - reason of the abort to be passed to the peer
4900 * The return value is the disposition.
4902 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4904 const struct sctp_endpoint *ep,
4905 const struct sctp_association *asoc,
4906 const sctp_subtype_t type,
4908 sctp_cmd_seq_t *commands)
4910 /* From 9.1 Abort of an Association
4911 * Upon receipt of the ABORT primitive from its upper
4912 * layer, the endpoint enters CLOSED state and
4913 * discard all outstanding data has been
4914 * acknowledged by its peer. The endpoint accepts no new data
4915 * from its upper layer, but retransmits data to the far end
4916 * if necessary to fill gaps.
4918 struct sctp_chunk *abort = arg;
4921 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4923 /* Even if we can't send the ABORT due to low memory delete the
4924 * TCB. This is a departure from our typical NOMEM handling.
4927 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4928 SCTP_ERROR(ECONNABORTED));
4929 /* Delete the established association. */
4930 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4931 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4933 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4934 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4936 return SCTP_DISPOSITION_ABORT;
4939 /* We tried an illegal operation on an association which is closed. */
4940 sctp_disposition_t sctp_sf_error_closed(struct net *net,
4941 const struct sctp_endpoint *ep,
4942 const struct sctp_association *asoc,
4943 const sctp_subtype_t type,
4945 sctp_cmd_seq_t *commands)
4947 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4948 return SCTP_DISPOSITION_CONSUME;
4951 /* We tried an illegal operation on an association which is shutting
4954 sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4955 const struct sctp_endpoint *ep,
4956 const struct sctp_association *asoc,
4957 const sctp_subtype_t type,
4959 sctp_cmd_seq_t *commands)
4961 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4962 SCTP_ERROR(-ESHUTDOWN));
4963 return SCTP_DISPOSITION_CONSUME;
4967 * sctp_cookie_wait_prm_shutdown
4969 * Section: 4 Note: 2
4974 * The RFC does not explicitly address this issue, but is the route through the
4975 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4980 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4982 const struct sctp_endpoint *ep,
4983 const struct sctp_association *asoc,
4984 const sctp_subtype_t type,
4986 sctp_cmd_seq_t *commands)
4988 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4989 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4991 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4992 SCTP_STATE(SCTP_STATE_CLOSED));
4994 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
4996 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4998 return SCTP_DISPOSITION_DELETE_TCB;
5002 * sctp_cookie_echoed_prm_shutdown
5004 * Section: 4 Note: 2
5009 * The RFC does not explcitly address this issue, but is the route through the
5010 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
5015 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
5017 const struct sctp_endpoint *ep,
5018 const struct sctp_association *asoc,
5019 const sctp_subtype_t type,
5020 void *arg, sctp_cmd_seq_t *commands)
5022 /* There is a single T1 timer, so we should be able to use
5023 * common function with the COOKIE-WAIT state.
5025 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
5029 * sctp_sf_cookie_wait_prm_abort
5031 * Section: 4 Note: 2
5036 * The RFC does not explicitly address this issue, but is the route through the
5037 * state table when someone issues an abort while in COOKIE_WAIT state.
5042 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
5044 const struct sctp_endpoint *ep,
5045 const struct sctp_association *asoc,
5046 const sctp_subtype_t type,
5048 sctp_cmd_seq_t *commands)
5050 struct sctp_chunk *abort = arg;
5052 /* Stop T1-init timer */
5053 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5054 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5057 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
5059 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5060 SCTP_STATE(SCTP_STATE_CLOSED));
5062 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5064 /* Even if we can't send the ABORT due to low memory delete the
5065 * TCB. This is a departure from our typical NOMEM handling.
5068 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5069 SCTP_ERROR(ECONNREFUSED));
5070 /* Delete the established association. */
5071 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5072 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5074 return SCTP_DISPOSITION_ABORT;
5078 * sctp_sf_cookie_echoed_prm_abort
5080 * Section: 4 Note: 3
5085 * The RFC does not explcitly address this issue, but is the route through the
5086 * state table when someone issues an abort while in COOKIE_ECHOED state.
5091 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
5093 const struct sctp_endpoint *ep,
5094 const struct sctp_association *asoc,
5095 const sctp_subtype_t type,
5097 sctp_cmd_seq_t *commands)
5099 /* There is a single T1 timer, so we should be able to use
5100 * common function with the COOKIE-WAIT state.
5102 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5106 * sctp_sf_shutdown_pending_prm_abort
5111 * The RFC does not explicitly address this issue, but is the route through the
5112 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5117 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
5119 const struct sctp_endpoint *ep,
5120 const struct sctp_association *asoc,
5121 const sctp_subtype_t type,
5123 sctp_cmd_seq_t *commands)
5125 /* Stop the T5-shutdown guard timer. */
5126 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5127 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5129 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5133 * sctp_sf_shutdown_sent_prm_abort
5138 * The RFC does not explicitly address this issue, but is the route through the
5139 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5144 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
5146 const struct sctp_endpoint *ep,
5147 const struct sctp_association *asoc,
5148 const sctp_subtype_t type,
5150 sctp_cmd_seq_t *commands)
5152 /* Stop the T2-shutdown timer. */
5153 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5154 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5156 /* Stop the T5-shutdown guard timer. */
5157 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5158 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5160 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5164 * sctp_sf_cookie_echoed_prm_abort
5169 * The RFC does not explcitly address this issue, but is the route through the
5170 * state table when someone issues an abort while in COOKIE_ECHOED state.
5175 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
5177 const struct sctp_endpoint *ep,
5178 const struct sctp_association *asoc,
5179 const sctp_subtype_t type,
5181 sctp_cmd_seq_t *commands)
5183 /* The same T2 timer, so we should be able to use
5184 * common function with the SHUTDOWN-SENT state.
5186 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5190 * Process the REQUESTHEARTBEAT primitive
5193 * J) Request Heartbeat
5195 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5199 * Instructs the local endpoint to perform a HeartBeat on the specified
5200 * destination transport address of the given association. The returned
5201 * result should indicate whether the transmission of the HEARTBEAT
5202 * chunk to the destination address is successful.
5204 * Mandatory attributes:
5206 * o association id - local handle to the SCTP association
5208 * o destination transport address - the transport address of the
5209 * association on which a heartbeat should be issued.
5211 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5213 const struct sctp_endpoint *ep,
5214 const struct sctp_association *asoc,
5215 const sctp_subtype_t type,
5217 sctp_cmd_seq_t *commands)
5219 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5220 (struct sctp_transport *)arg, commands))
5221 return SCTP_DISPOSITION_NOMEM;
5224 * RFC 2960 (bis), section 8.3
5226 * D) Request an on-demand HEARTBEAT on a specific destination
5227 * transport address of a given association.
5229 * The endpoint should increment the respective error counter of
5230 * the destination transport address each time a HEARTBEAT is sent
5231 * to that address and not acknowledged within one RTO.
5234 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5235 SCTP_TRANSPORT(arg));
5236 return SCTP_DISPOSITION_CONSUME;
5240 * ADDIP Section 4.1 ASCONF Chunk Procedures
5241 * When an endpoint has an ASCONF signaled change to be sent to the
5242 * remote endpoint it should do A1 to A9
5244 sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5245 const struct sctp_endpoint *ep,
5246 const struct sctp_association *asoc,
5247 const sctp_subtype_t type,
5249 sctp_cmd_seq_t *commands)
5251 struct sctp_chunk *chunk = arg;
5253 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5254 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5255 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5256 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5257 return SCTP_DISPOSITION_CONSUME;
5260 /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5261 sctp_disposition_t sctp_sf_do_prm_reconf(struct net *net,
5262 const struct sctp_endpoint *ep,
5263 const struct sctp_association *asoc,
5264 const sctp_subtype_t type,
5265 void *arg, sctp_cmd_seq_t *commands)
5267 struct sctp_chunk *chunk = arg;
5269 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5270 return SCTP_DISPOSITION_CONSUME;
5274 * Ignore the primitive event
5276 * The return value is the disposition of the primitive.
5278 sctp_disposition_t sctp_sf_ignore_primitive(
5280 const struct sctp_endpoint *ep,
5281 const struct sctp_association *asoc,
5282 const sctp_subtype_t type,
5284 sctp_cmd_seq_t *commands)
5286 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5289 return SCTP_DISPOSITION_DISCARD;
5292 /***************************************************************************
5293 * These are the state functions for the OTHER events.
5294 ***************************************************************************/
5297 * When the SCTP stack has no more user data to send or retransmit, this
5298 * notification is given to the user. Also, at the time when a user app
5299 * subscribes to this event, if there is no data to be sent or
5300 * retransmit, the stack will immediately send up this notification.
5302 sctp_disposition_t sctp_sf_do_no_pending_tsn(
5304 const struct sctp_endpoint *ep,
5305 const struct sctp_association *asoc,
5306 const sctp_subtype_t type,
5308 sctp_cmd_seq_t *commands)
5310 struct sctp_ulpevent *event;
5312 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5314 return SCTP_DISPOSITION_NOMEM;
5316 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5318 return SCTP_DISPOSITION_CONSUME;
5322 * Start the shutdown negotiation.
5325 * Once all its outstanding data has been acknowledged, the endpoint
5326 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5327 * TSN Ack field the last sequential TSN it has received from the peer.
5328 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5329 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5330 * with the updated last sequential TSN received from its peer.
5332 * The return value is the disposition.
5334 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5336 const struct sctp_endpoint *ep,
5337 const struct sctp_association *asoc,
5338 const sctp_subtype_t type,
5340 sctp_cmd_seq_t *commands)
5342 struct sctp_chunk *reply;
5344 /* Once all its outstanding data has been acknowledged, the
5345 * endpoint shall send a SHUTDOWN chunk to its peer including
5346 * in the Cumulative TSN Ack field the last sequential TSN it
5347 * has received from the peer.
5349 reply = sctp_make_shutdown(asoc, NULL);
5353 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5354 * T2-shutdown timer.
5356 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5358 /* It shall then start the T2-shutdown timer */
5359 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5360 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5362 /* RFC 4960 Section 9.2
5363 * The sender of the SHUTDOWN MAY also start an overall guard timer
5364 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5366 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5367 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5369 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5370 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5371 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5373 /* and enter the SHUTDOWN-SENT state. */
5374 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5375 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5377 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5379 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5382 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5384 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5386 return SCTP_DISPOSITION_CONSUME;
5389 return SCTP_DISPOSITION_NOMEM;
5393 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5397 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5398 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5399 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5400 * endpoint must re-send the SHUTDOWN ACK.
5402 * The return value is the disposition.
5404 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5406 const struct sctp_endpoint *ep,
5407 const struct sctp_association *asoc,
5408 const sctp_subtype_t type,
5410 sctp_cmd_seq_t *commands)
5412 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5413 struct sctp_chunk *reply;
5415 /* There are 2 ways of getting here:
5416 * 1) called in response to a SHUTDOWN chunk
5417 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5419 * For the case (2), the arg parameter is set to NULL. We need
5420 * to check that we have a chunk before accessing it's fields.
5423 if (!sctp_vtag_verify(chunk, asoc))
5424 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
5426 /* Make sure that the SHUTDOWN chunk has a valid length. */
5427 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5428 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
5432 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5433 * shall send a SHUTDOWN ACK ...
5435 reply = sctp_make_shutdown_ack(asoc, chunk);
5439 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5440 * the T2-shutdown timer.
5442 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5444 /* and start/restart a T2-shutdown timer of its own, */
5445 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5446 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5448 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5449 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5450 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5452 /* Enter the SHUTDOWN-ACK-SENT state. */
5453 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5454 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5456 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5458 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5461 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5463 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5465 return SCTP_DISPOSITION_CONSUME;
5468 return SCTP_DISPOSITION_NOMEM;
5472 * Ignore the event defined as other
5474 * The return value is the disposition of the event.
5476 sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5477 const struct sctp_endpoint *ep,
5478 const struct sctp_association *asoc,
5479 const sctp_subtype_t type,
5481 sctp_cmd_seq_t *commands)
5483 pr_debug("%s: the event other type:%d is ignored\n",
5484 __func__, type.other);
5486 return SCTP_DISPOSITION_DISCARD;
5489 /************************************************************
5490 * These are the state functions for handling timeout events.
5491 ************************************************************/
5496 * Section: 6.3.3 Handle T3-rtx Expiration
5498 * Whenever the retransmission timer T3-rtx expires for a destination
5499 * address, do the following:
5502 * The return value is the disposition of the chunk.
5504 sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5505 const struct sctp_endpoint *ep,
5506 const struct sctp_association *asoc,
5507 const sctp_subtype_t type,
5509 sctp_cmd_seq_t *commands)
5511 struct sctp_transport *transport = arg;
5513 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5515 if (asoc->overall_error_count >= asoc->max_retrans) {
5516 if (asoc->peer.zero_window_announced &&
5517 asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5519 * We are here likely because the receiver had its rwnd
5520 * closed for a while and we have not been able to
5521 * transmit the locally queued data within the maximum
5522 * retransmission attempts limit. Start the T5
5523 * shutdown guard timer to give the receiver one last
5524 * chance and some additional time to recover before
5527 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5528 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5530 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5531 SCTP_ERROR(ETIMEDOUT));
5532 /* 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(net, SCTP_MIB_ABORTEDS);
5536 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5537 return SCTP_DISPOSITION_DELETE_TCB;
5541 /* E1) For the destination address for which the timer
5542 * expires, adjust its ssthresh with rules defined in Section
5543 * 7.2.3 and set the cwnd <- MTU.
5546 /* E2) For the destination address for which the timer
5547 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5548 * maximum value discussed in rule C7 above (RTO.max) may be
5549 * used to provide an upper bound to this doubling operation.
5552 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5553 * outstanding DATA chunks for the address for which the
5554 * T3-rtx has expired will fit into a single packet, subject
5555 * to the MTU constraint for the path corresponding to the
5556 * destination transport address to which the retransmission
5557 * is being sent (this may be different from the address for
5558 * which the timer expires [see Section 6.4]). Call this
5559 * value K. Bundle and retransmit those K DATA chunks in a
5560 * single packet to the destination endpoint.
5562 * Note: Any DATA chunks that were sent to the address for
5563 * which the T3-rtx timer expired but did not fit in one MTU
5564 * (rule E3 above), should be marked for retransmission and
5565 * sent as soon as cwnd allows (normally when a SACK arrives).
5568 /* Do some failure management (Section 8.2). */
5569 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5571 /* NB: Rules E4 and F1 are implicit in R1. */
5572 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5574 return SCTP_DISPOSITION_CONSUME;
5578 * Generate delayed SACK on timeout
5580 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5582 * The guidelines on delayed acknowledgement algorithm specified in
5583 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5584 * acknowledgement SHOULD be generated for at least every second packet
5585 * (not every second DATA chunk) received, and SHOULD be generated
5586 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5587 * some situations it may be beneficial for an SCTP transmitter to be
5588 * more conservative than the algorithms detailed in this document
5589 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5590 * the following algorithms allow.
5592 sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5593 const struct sctp_endpoint *ep,
5594 const struct sctp_association *asoc,
5595 const sctp_subtype_t type,
5597 sctp_cmd_seq_t *commands)
5599 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5600 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5601 return SCTP_DISPOSITION_CONSUME;
5605 * sctp_sf_t1_init_timer_expire
5607 * Section: 4 Note: 2
5612 * RFC 2960 Section 4 Notes
5613 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5614 * and re-start the T1-init timer without changing state. This MUST
5615 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5616 * endpoint MUST abort the initialization process and report the
5617 * error to SCTP user.
5623 sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5624 const struct sctp_endpoint *ep,
5625 const struct sctp_association *asoc,
5626 const sctp_subtype_t type,
5628 sctp_cmd_seq_t *commands)
5630 struct sctp_chunk *repl = NULL;
5631 struct sctp_bind_addr *bp;
5632 int attempts = asoc->init_err_counter + 1;
5634 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5636 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5638 if (attempts <= asoc->max_init_attempts) {
5639 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5640 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5642 return SCTP_DISPOSITION_NOMEM;
5644 /* Choose transport for INIT. */
5645 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5648 /* Issue a sideeffect to do the needed accounting. */
5649 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5650 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5652 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5654 pr_debug("%s: giving up on INIT, attempts:%d "
5655 "max_init_attempts:%d\n", __func__, attempts,
5656 asoc->max_init_attempts);
5658 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5659 SCTP_ERROR(ETIMEDOUT));
5660 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5661 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5662 return SCTP_DISPOSITION_DELETE_TCB;
5665 return SCTP_DISPOSITION_CONSUME;
5669 * sctp_sf_t1_cookie_timer_expire
5671 * Section: 4 Note: 2
5676 * RFC 2960 Section 4 Notes
5677 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5678 * COOKIE ECHO and re-start the T1-cookie timer without changing
5679 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5680 * After that, the endpoint MUST abort the initialization process and
5681 * report the error to SCTP user.
5687 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5688 const struct sctp_endpoint *ep,
5689 const struct sctp_association *asoc,
5690 const sctp_subtype_t type,
5692 sctp_cmd_seq_t *commands)
5694 struct sctp_chunk *repl = NULL;
5695 int attempts = asoc->init_err_counter + 1;
5697 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5699 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5701 if (attempts <= asoc->max_init_attempts) {
5702 repl = sctp_make_cookie_echo(asoc, NULL);
5704 return SCTP_DISPOSITION_NOMEM;
5706 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5708 /* Issue a sideeffect to do the needed accounting. */
5709 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5710 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5712 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5714 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5715 SCTP_ERROR(ETIMEDOUT));
5716 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5717 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5718 return SCTP_DISPOSITION_DELETE_TCB;
5721 return SCTP_DISPOSITION_CONSUME;
5724 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5725 * with the updated last sequential TSN received from its peer.
5727 * An endpoint should limit the number of retransmissions of the
5728 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5729 * If this threshold is exceeded the endpoint should destroy the TCB and
5730 * MUST report the peer endpoint unreachable to the upper layer (and
5731 * thus the association enters the CLOSED state). The reception of any
5732 * packet from its peer (i.e. as the peer sends all of its queued DATA
5733 * chunks) should clear the endpoint's retransmission count and restart
5734 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5735 * all of its queued DATA chunks that have not yet been sent.
5737 sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5738 const struct sctp_endpoint *ep,
5739 const struct sctp_association *asoc,
5740 const sctp_subtype_t type,
5742 sctp_cmd_seq_t *commands)
5744 struct sctp_chunk *reply = NULL;
5746 pr_debug("%s: timer T2 expired\n", __func__);
5748 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5750 ((struct sctp_association *)asoc)->shutdown_retries++;
5752 if (asoc->overall_error_count >= asoc->max_retrans) {
5753 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5754 SCTP_ERROR(ETIMEDOUT));
5755 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5756 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5757 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5758 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5759 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5760 return SCTP_DISPOSITION_DELETE_TCB;
5763 switch (asoc->state) {
5764 case SCTP_STATE_SHUTDOWN_SENT:
5765 reply = sctp_make_shutdown(asoc, NULL);
5768 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5769 reply = sctp_make_shutdown_ack(asoc, NULL);
5780 /* Do some failure management (Section 8.2).
5781 * If we remove the transport an SHUTDOWN was last sent to, don't
5782 * do failure management.
5784 if (asoc->shutdown_last_sent_to)
5785 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5786 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5788 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5789 * the T2-shutdown timer.
5791 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5793 /* Restart the T2-shutdown timer. */
5794 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5795 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5796 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5797 return SCTP_DISPOSITION_CONSUME;
5800 return SCTP_DISPOSITION_NOMEM;
5804 * ADDIP Section 4.1 ASCONF CHunk Procedures
5805 * If the T4 RTO timer expires the endpoint should do B1 to B5
5807 sctp_disposition_t sctp_sf_t4_timer_expire(
5809 const struct sctp_endpoint *ep,
5810 const struct sctp_association *asoc,
5811 const sctp_subtype_t type,
5813 sctp_cmd_seq_t *commands)
5815 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5816 struct sctp_transport *transport = chunk->transport;
5818 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
5820 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5821 * detection on the appropriate destination address as defined in
5822 * RFC2960 [5] section 8.1 and 8.2.
5825 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5826 SCTP_TRANSPORT(transport));
5828 /* Reconfig T4 timer and transport. */
5829 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5831 /* ADDIP 4.1 B2) Increment the association error counters and perform
5832 * endpoint failure detection on the association as defined in
5833 * RFC2960 [5] section 8.1 and 8.2.
5834 * association error counter is incremented in SCTP_CMD_STRIKE.
5836 if (asoc->overall_error_count >= asoc->max_retrans) {
5837 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5838 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5839 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5840 SCTP_ERROR(ETIMEDOUT));
5841 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5842 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5843 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5844 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5845 return SCTP_DISPOSITION_ABORT;
5848 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5849 * the ASCONF chunk was sent by doubling the RTO timer value.
5850 * This is done in SCTP_CMD_STRIKE.
5853 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5854 * choose an alternate destination address (please refer to RFC2960
5855 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5856 * chunk, it MUST be the same (including its serial number) as the last
5859 sctp_chunk_hold(asoc->addip_last_asconf);
5860 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5861 SCTP_CHUNK(asoc->addip_last_asconf));
5863 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5864 * destination is selected, then the RTO used will be that of the new
5865 * destination address.
5867 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5868 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5870 return SCTP_DISPOSITION_CONSUME;
5873 /* sctpimpguide-05 Section 2.12.2
5874 * The sender of the SHUTDOWN MAY also start an overall guard timer
5875 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5876 * At the expiration of this timer the sender SHOULD abort the association
5877 * by sending an ABORT chunk.
5879 sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5880 const struct sctp_endpoint *ep,
5881 const struct sctp_association *asoc,
5882 const sctp_subtype_t type,
5884 sctp_cmd_seq_t *commands)
5886 struct sctp_chunk *reply = NULL;
5888 pr_debug("%s: timer T5 expired\n", __func__);
5890 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5892 reply = sctp_make_abort(asoc, NULL, 0);
5896 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5897 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5898 SCTP_ERROR(ETIMEDOUT));
5899 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5900 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5902 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5903 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5905 return SCTP_DISPOSITION_DELETE_TCB;
5907 return SCTP_DISPOSITION_NOMEM;
5910 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5911 * the association is automatically closed by starting the shutdown process.
5912 * The work that needs to be done is same as when SHUTDOWN is initiated by
5913 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5915 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5917 const struct sctp_endpoint *ep,
5918 const struct sctp_association *asoc,
5919 const sctp_subtype_t type,
5921 sctp_cmd_seq_t *commands)
5925 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
5927 /* From 9.2 Shutdown of an Association
5928 * Upon receipt of the SHUTDOWN primitive from its upper
5929 * layer, the endpoint enters SHUTDOWN-PENDING state and
5930 * remains there until all outstanding data has been
5931 * acknowledged by its peer. The endpoint accepts no new data
5932 * from its upper layer, but retransmits data to the far end
5933 * if necessary to fill gaps.
5935 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5936 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5938 disposition = SCTP_DISPOSITION_CONSUME;
5939 if (sctp_outq_is_empty(&asoc->outqueue)) {
5940 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
5946 /*****************************************************************************
5947 * These are sa state functions which could apply to all types of events.
5948 ****************************************************************************/
5951 * This table entry is not implemented.
5954 * (endpoint, asoc, chunk)
5956 * The return value is the disposition of the chunk.
5958 sctp_disposition_t sctp_sf_not_impl(struct net *net,
5959 const struct sctp_endpoint *ep,
5960 const struct sctp_association *asoc,
5961 const sctp_subtype_t type,
5963 sctp_cmd_seq_t *commands)
5965 return SCTP_DISPOSITION_NOT_IMPL;
5969 * This table entry represents a bug.
5972 * (endpoint, asoc, chunk)
5974 * The return value is the disposition of the chunk.
5976 sctp_disposition_t sctp_sf_bug(struct net *net,
5977 const struct sctp_endpoint *ep,
5978 const struct sctp_association *asoc,
5979 const sctp_subtype_t type,
5981 sctp_cmd_seq_t *commands)
5983 return SCTP_DISPOSITION_BUG;
5987 * This table entry represents the firing of a timer in the wrong state.
5988 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5989 * when the association is in the wrong state. This event should
5990 * be ignored, so as to prevent any rearming of the timer.
5993 * (endpoint, asoc, chunk)
5995 * The return value is the disposition of the chunk.
5997 sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5998 const struct sctp_endpoint *ep,
5999 const struct sctp_association *asoc,
6000 const sctp_subtype_t type,
6002 sctp_cmd_seq_t *commands)
6004 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
6006 return SCTP_DISPOSITION_CONSUME;
6009 /********************************************************************
6010 * 2nd Level Abstractions
6011 ********************************************************************/
6013 /* Pull the SACK chunk based on the SACK header. */
6014 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
6016 struct sctp_sackhdr *sack;
6021 /* Protect ourselves from reading too far into
6022 * the skb from a bogus sender.
6024 sack = (struct sctp_sackhdr *) chunk->skb->data;
6026 num_blocks = ntohs(sack->num_gap_ack_blocks);
6027 num_dup_tsns = ntohs(sack->num_dup_tsns);
6028 len = sizeof(struct sctp_sackhdr);
6029 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
6030 if (len > chunk->skb->len)
6033 skb_pull(chunk->skb, len);
6038 /* Create an ABORT packet to be sent as a response, with the specified
6041 static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
6042 const struct sctp_endpoint *ep,
6043 const struct sctp_association *asoc,
6044 struct sctp_chunk *chunk,
6045 const void *payload,
6048 struct sctp_packet *packet;
6049 struct sctp_chunk *abort;
6051 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6055 * The T bit will be set if the asoc is NULL.
6057 abort = sctp_make_abort(asoc, chunk, paylen);
6059 sctp_ootb_pkt_free(packet);
6063 /* Reflect vtag if T-Bit is set */
6064 if (sctp_test_T_bit(abort))
6065 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
6067 /* Add specified error causes, i.e., payload, to the
6070 sctp_addto_chunk(abort, paylen, payload);
6072 /* Set the skb to the belonging sock for accounting. */
6073 abort->skb->sk = ep->base.sk;
6075 sctp_packet_append_chunk(packet, abort);
6082 /* Allocate a packet for responding in the OOTB conditions. */
6083 static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
6084 const struct sctp_association *asoc,
6085 const struct sctp_chunk *chunk)
6087 struct sctp_packet *packet;
6088 struct sctp_transport *transport;
6093 /* Get the source and destination port from the inbound packet. */
6094 sport = ntohs(chunk->sctp_hdr->dest);
6095 dport = ntohs(chunk->sctp_hdr->source);
6097 /* The V-tag is going to be the same as the inbound packet if no
6098 * association exists, otherwise, use the peer's vtag.
6101 /* Special case the INIT-ACK as there is no peer's vtag
6104 switch (chunk->chunk_hdr->type) {
6105 case SCTP_CID_INIT_ACK:
6107 sctp_initack_chunk_t *initack;
6109 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6110 vtag = ntohl(initack->init_hdr.init_tag);
6114 vtag = asoc->peer.i.init_tag;
6118 /* Special case the INIT and stale COOKIE_ECHO as there is no
6121 switch (chunk->chunk_hdr->type) {
6124 sctp_init_chunk_t *init;
6126 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6127 vtag = ntohl(init->init_hdr.init_tag);
6131 vtag = ntohl(chunk->sctp_hdr->vtag);
6136 /* Make a transport for the bucket, Eliza... */
6137 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6141 /* Cache a route for the transport with the chunk's destination as
6142 * the source address.
6144 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6145 sctp_sk(net->sctp.ctl_sock));
6147 packet = &transport->packet;
6148 sctp_packet_init(packet, transport, sport, dport);
6149 sctp_packet_config(packet, vtag, 0);
6157 /* Free the packet allocated earlier for responding in the OOTB condition. */
6158 void sctp_ootb_pkt_free(struct sctp_packet *packet)
6160 sctp_transport_free(packet->transport);
6163 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6164 static void sctp_send_stale_cookie_err(struct net *net,
6165 const struct sctp_endpoint *ep,
6166 const struct sctp_association *asoc,
6167 const struct sctp_chunk *chunk,
6168 sctp_cmd_seq_t *commands,
6169 struct sctp_chunk *err_chunk)
6171 struct sctp_packet *packet;
6174 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6176 struct sctp_signed_cookie *cookie;
6178 /* Override the OOTB vtag from the cookie. */
6179 cookie = chunk->subh.cookie_hdr;
6180 packet->vtag = cookie->c.peer_vtag;
6182 /* Set the skb to the belonging sock for accounting. */
6183 err_chunk->skb->sk = ep->base.sk;
6184 sctp_packet_append_chunk(packet, err_chunk);
6185 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6186 SCTP_PACKET(packet));
6187 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6189 sctp_chunk_free (err_chunk);
6194 /* Process a data chunk */
6195 static int sctp_eat_data(const struct sctp_association *asoc,
6196 struct sctp_chunk *chunk,
6197 sctp_cmd_seq_t *commands)
6199 sctp_datahdr_t *data_hdr;
6200 struct sctp_chunk *err;
6202 sctp_verb_t deliver;
6205 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6206 struct sock *sk = asoc->base.sk;
6207 struct net *net = sock_net(sk);
6212 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6213 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6215 tsn = ntohl(data_hdr->tsn);
6216 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6218 /* ASSERT: Now skb->data is really the user data. */
6220 /* Process ECN based congestion.
6222 * Since the chunk structure is reused for all chunks within
6223 * a packet, we use ecn_ce_done to track if we've already
6224 * done CE processing for this packet.
6226 * We need to do ECN processing even if we plan to discard the
6230 if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) {
6231 struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af;
6232 chunk->ecn_ce_done = 1;
6234 if (af->is_ce(sctp_gso_headskb(chunk->skb))) {
6235 /* Do real work as sideffect. */
6236 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6241 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6243 /* The TSN is too high--silently discard the chunk and
6244 * count on it getting retransmitted later.
6247 chunk->asoc->stats.outofseqtsns++;
6248 return SCTP_IERROR_HIGH_TSN;
6249 } else if (tmp > 0) {
6250 /* This is a duplicate. Record it. */
6251 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6252 return SCTP_IERROR_DUP_TSN;
6255 /* This is a new TSN. */
6257 /* Discard if there is no room in the receive window.
6258 * Actually, allow a little bit of overflow (up to a MTU).
6260 datalen = ntohs(chunk->chunk_hdr->length);
6261 datalen -= sizeof(sctp_data_chunk_t);
6263 deliver = SCTP_CMD_CHUNK_ULP;
6265 /* Think about partial delivery. */
6266 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6268 /* Even if we don't accept this chunk there is
6271 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6274 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6275 * seems a bit troublesome in that frag_point varies based on
6276 * PMTU. In cases, such as loopback, this might be a rather
6279 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6280 (datalen > asoc->rwnd + asoc->frag_point))) {
6282 /* If this is the next TSN, consider reneging to make
6283 * room. Note: Playing nice with a confused sender. A
6284 * malicious sender can still eat up all our buffer
6285 * space and in the future we may want to detect and
6286 * do more drastic reneging.
6288 if (sctp_tsnmap_has_gap(map) &&
6289 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6290 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6291 deliver = SCTP_CMD_RENEGE;
6293 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6294 __func__, tsn, datalen, asoc->rwnd);
6296 return SCTP_IERROR_IGNORE_TSN;
6301 * Also try to renege to limit our memory usage in the event that
6302 * we are under memory pressure
6303 * If we can't renege, don't worry about it, the sk_rmem_schedule
6304 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6305 * memory usage too much
6307 if (*sk->sk_prot_creator->memory_pressure) {
6308 if (sctp_tsnmap_has_gap(map) &&
6309 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6310 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6312 deliver = SCTP_CMD_RENEGE;
6317 * Section 3.3.10.9 No User Data (9)
6321 * No User Data: This error cause is returned to the originator of a
6322 * DATA chunk if a received DATA chunk has no user data.
6324 if (unlikely(0 == datalen)) {
6325 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6327 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6330 /* We are going to ABORT, so we might as well stop
6331 * processing the rest of the chunks in the packet.
6333 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6334 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6335 SCTP_ERROR(ECONNABORTED));
6336 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6337 SCTP_PERR(SCTP_ERROR_NO_DATA));
6338 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6339 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6340 return SCTP_IERROR_NO_DATA;
6343 chunk->data_accepted = 1;
6345 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6346 * if we renege and the chunk arrives again.
6348 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6349 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6351 chunk->asoc->stats.iuodchunks++;
6353 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6355 chunk->asoc->stats.iodchunks++;
6359 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6361 * If an endpoint receive a DATA chunk with an invalid stream
6362 * identifier, it shall acknowledge the reception of the DATA chunk
6363 * following the normal procedure, immediately send an ERROR chunk
6364 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6365 * and discard the DATA chunk.
6367 sid = ntohs(data_hdr->stream);
6368 if (sid >= asoc->stream->incnt) {
6369 /* Mark tsn as received even though we drop it */
6370 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6372 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6374 sizeof(data_hdr->stream),
6377 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6379 return SCTP_IERROR_BAD_STREAM;
6382 /* Check to see if the SSN is possible for this TSN.
6383 * The biggest gap we can record is 4K wide. Since SSNs wrap
6384 * at an unsigned short, there is no way that an SSN can
6385 * wrap and for a valid TSN. We can simply check if the current
6386 * SSN is smaller then the next expected one. If it is, it wrapped
6389 ssn = ntohs(data_hdr->ssn);
6390 if (ordered && SSN_lt(ssn, sctp_ssn_peek(asoc->stream, in, sid)))
6391 return SCTP_IERROR_PROTO_VIOLATION;
6393 /* Send the data up to the user. Note: Schedule the
6394 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6395 * chunk needs the updated rwnd.
6397 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6399 return SCTP_IERROR_NO_ERROR;