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: 1 = Valid length
168 sctp_chunk_length_valid(struct sctp_chunk *chunk,
169 __u16 required_length)
171 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
173 if (unlikely(chunk_length < required_length))
179 /**********************************************************
180 * These are the state functions for handling chunk events.
181 **********************************************************/
184 * Process the final SHUTDOWN COMPLETE.
186 * Section: 4 (C) (diagram), 9.2
187 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
188 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
189 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
190 * should stop the T2-shutdown timer and remove all knowledge of the
191 * association (and thus the association enters the CLOSED state).
193 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
194 * C) Rules for packet carrying SHUTDOWN COMPLETE:
196 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
197 * if the Verification Tag field of the packet matches its own tag and
198 * the T bit is not set
200 * it is set to its peer's tag and the T bit is set in the Chunk
202 * Otherwise, the receiver MUST silently discard the packet
203 * and take no further action. An endpoint MUST ignore the
204 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
207 * (endpoint, asoc, chunk)
210 * (asoc, reply_msg, msg_up, timers, counters)
212 * The return value is the disposition of the chunk.
214 sctp_disposition_t sctp_sf_do_4_C(struct net *net,
215 const struct sctp_endpoint *ep,
216 const struct sctp_association *asoc,
217 const sctp_subtype_t type,
219 sctp_cmd_seq_t *commands)
221 struct sctp_chunk *chunk = arg;
222 struct sctp_ulpevent *ev;
224 if (!sctp_vtag_verify_either(chunk, asoc))
225 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
227 /* RFC 2960 6.10 Bundling
229 * An endpoint MUST NOT bundle INIT, INIT ACK or
230 * SHUTDOWN COMPLETE with any other chunks.
232 if (!chunk->singleton)
233 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
235 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
236 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
237 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
240 /* RFC 2960 10.2 SCTP-to-ULP
242 * H) SHUTDOWN COMPLETE notification
244 * When SCTP completes the shutdown procedures (section 9.2) this
245 * notification is passed to the upper layer.
247 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
248 0, 0, 0, NULL, GFP_ATOMIC);
250 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
253 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
254 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
255 * not the chunk should be discarded. If the endpoint is in
256 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
257 * T2-shutdown timer and remove all knowledge of the
258 * association (and thus the association enters the CLOSED
261 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
262 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
264 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
265 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
267 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
268 SCTP_STATE(SCTP_STATE_CLOSED));
270 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
271 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
273 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
275 return SCTP_DISPOSITION_DELETE_TCB;
279 * Respond to a normal INIT chunk.
280 * We are the side that is being asked for an association.
282 * Section: 5.1 Normal Establishment of an Association, B
283 * B) "Z" shall respond immediately with an INIT ACK chunk. The
284 * destination IP address of the INIT ACK MUST be set to the source
285 * IP address of the INIT to which this INIT ACK is responding. In
286 * the response, besides filling in other parameters, "Z" must set the
287 * Verification Tag field to Tag_A, and also provide its own
288 * Verification Tag (Tag_Z) in the Initiate Tag field.
290 * Verification Tag: Must be 0.
293 * (endpoint, asoc, chunk)
296 * (asoc, reply_msg, msg_up, timers, counters)
298 * The return value is the disposition of the chunk.
300 sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
301 const struct sctp_endpoint *ep,
302 const struct sctp_association *asoc,
303 const sctp_subtype_t type,
305 sctp_cmd_seq_t *commands)
307 struct sctp_chunk *chunk = arg;
308 struct sctp_chunk *repl;
309 struct sctp_association *new_asoc;
310 struct sctp_chunk *err_chunk;
311 struct sctp_packet *packet;
312 sctp_unrecognized_param_t *unk_param;
316 * An endpoint MUST NOT bundle INIT, INIT ACK or
317 * SHUTDOWN COMPLETE with any other chunks.
320 * Furthermore, we require that the receiver of an INIT chunk MUST
321 * enforce these rules by silently discarding an arriving packet
322 * with an INIT chunk that is bundled with other chunks.
324 if (!chunk->singleton)
325 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
327 /* If the packet is an OOTB packet which is temporarily on the
328 * control endpoint, respond with an ABORT.
330 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
331 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
332 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
335 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
338 if (chunk->sctp_hdr->vtag != 0)
339 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
341 /* Make sure that the INIT chunk has a valid length.
342 * Normally, this would cause an ABORT with a Protocol Violation
343 * error, but since we don't have an association, we'll
344 * just discard the packet.
346 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
347 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
349 /* If the INIT is coming toward a closing socket, we'll send back
350 * and ABORT. Essentially, this catches the race of INIT being
351 * backloged to the socket at the same time as the user isses close().
352 * Since the socket and all its associations are going away, we
353 * can treat this OOTB
355 if (sctp_sstate(ep->base.sk, CLOSING))
356 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
358 /* Verify the INIT chunk before processing it. */
360 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
361 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
363 /* This chunk contains fatal error. It is to be discarded.
364 * Send an ABORT, with causes if there is any.
367 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
368 (__u8 *)(err_chunk->chunk_hdr) +
369 sizeof(sctp_chunkhdr_t),
370 ntohs(err_chunk->chunk_hdr->length) -
371 sizeof(sctp_chunkhdr_t));
373 sctp_chunk_free(err_chunk);
376 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
377 SCTP_PACKET(packet));
378 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
379 return SCTP_DISPOSITION_CONSUME;
381 return SCTP_DISPOSITION_NOMEM;
384 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
389 /* Grab the INIT header. */
390 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
392 /* Tag the variable length parameters. */
393 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
395 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
399 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
400 sctp_scope(sctp_source(chunk)),
404 /* The call, sctp_process_init(), can fail on memory allocation. */
405 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
406 (sctp_init_chunk_t *)chunk->chunk_hdr,
410 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
412 /* If there are errors need to be reported for unknown parameters,
413 * make sure to reserve enough room in the INIT ACK for them.
417 len = ntohs(err_chunk->chunk_hdr->length) -
418 sizeof(sctp_chunkhdr_t);
420 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
424 /* If there are errors need to be reported for unknown parameters,
425 * include them in the outgoing INIT ACK as "Unrecognized parameter"
429 /* Get the "Unrecognized parameter" parameter(s) out of the
430 * ERROR chunk generated by sctp_verify_init(). Since the
431 * error cause code for "unknown parameter" and the
432 * "Unrecognized parameter" type is the same, we can
433 * construct the parameters in INIT ACK by copying the
436 unk_param = (sctp_unrecognized_param_t *)
437 ((__u8 *)(err_chunk->chunk_hdr) +
438 sizeof(sctp_chunkhdr_t));
439 /* Replace the cause code with the "Unrecognized parameter"
442 sctp_addto_chunk(repl, len, unk_param);
443 sctp_chunk_free(err_chunk);
446 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
448 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
451 * Note: After sending out INIT ACK with the State Cookie parameter,
452 * "Z" MUST NOT allocate any resources, nor keep any states for the
453 * new association. Otherwise, "Z" will be vulnerable to resource
456 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
458 return SCTP_DISPOSITION_DELETE_TCB;
461 sctp_association_free(new_asoc);
464 sctp_chunk_free(err_chunk);
465 return SCTP_DISPOSITION_NOMEM;
469 * Respond to a normal INIT ACK chunk.
470 * We are the side that is initiating the association.
472 * Section: 5.1 Normal Establishment of an Association, C
473 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
474 * timer and leave COOKIE-WAIT state. "A" shall then send the State
475 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
476 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
478 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
479 * DATA chunks, but it MUST be the first chunk in the packet and
480 * until the COOKIE ACK is returned the sender MUST NOT send any
481 * other packets to the peer.
483 * Verification Tag: 3.3.3
484 * If the value of the Initiate Tag in a received INIT ACK chunk is
485 * found to be 0, the receiver MUST treat it as an error and close the
486 * association by transmitting an ABORT.
489 * (endpoint, asoc, chunk)
492 * (asoc, reply_msg, msg_up, timers, counters)
494 * The return value is the disposition of the chunk.
496 sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
497 const struct sctp_endpoint *ep,
498 const struct sctp_association *asoc,
499 const sctp_subtype_t type,
501 sctp_cmd_seq_t *commands)
503 struct sctp_chunk *chunk = arg;
504 sctp_init_chunk_t *initchunk;
505 struct sctp_chunk *err_chunk;
506 struct sctp_packet *packet;
508 if (!sctp_vtag_verify(chunk, asoc))
509 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
512 * An endpoint MUST NOT bundle INIT, INIT ACK or
513 * SHUTDOWN COMPLETE with any other chunks.
515 if (!chunk->singleton)
516 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
518 /* Make sure that the INIT-ACK chunk has a valid length */
519 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
520 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
522 /* Grab the INIT header. */
523 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
525 /* Verify the INIT chunk before processing it. */
527 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
528 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
531 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
533 /* This chunk contains fatal error. It is to be discarded.
534 * Send an ABORT, with causes. If there are no causes,
535 * then there wasn't enough memory. Just terminate
539 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
540 (__u8 *)(err_chunk->chunk_hdr) +
541 sizeof(sctp_chunkhdr_t),
542 ntohs(err_chunk->chunk_hdr->length) -
543 sizeof(sctp_chunkhdr_t));
545 sctp_chunk_free(err_chunk);
548 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
549 SCTP_PACKET(packet));
550 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
551 error = SCTP_ERROR_INV_PARAM;
555 /* SCTP-AUTH, Section 6.3:
556 * It should be noted that if the receiver wants to tear
557 * down an association in an authenticated way only, the
558 * handling of malformed packets should not result in
559 * tearing down the association.
561 * This means that if we only want to abort associations
562 * in an authenticated way (i.e AUTH+ABORT), then we
563 * can't destroy this association just because the packet
566 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
567 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
569 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
570 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
571 asoc, chunk->transport);
574 /* Tag the variable length parameters. Note that we never
575 * convert the parameters in an INIT chunk.
577 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
579 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
581 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
582 SCTP_PEER_INIT(initchunk));
584 /* Reset init error count upon receipt of INIT-ACK. */
585 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
587 /* 5.1 C) "A" shall stop the T1-init timer and leave
588 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
589 * timer, and enter the COOKIE-ECHOED state.
591 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
592 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
593 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
595 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
596 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
598 /* SCTP-AUTH: genereate the assocition shared keys so that
599 * we can potentially signe the COOKIE-ECHO.
601 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
603 /* 5.1 C) "A" shall then send the State Cookie received in the
604 * INIT ACK chunk in a COOKIE ECHO chunk, ...
606 /* If there is any errors to report, send the ERROR chunk generated
607 * for unknown parameters as well.
609 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
610 SCTP_CHUNK(err_chunk));
612 return SCTP_DISPOSITION_CONSUME;
616 * Respond to a normal COOKIE ECHO chunk.
617 * We are the side that is being asked for an association.
619 * Section: 5.1 Normal Establishment of an Association, D
620 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
621 * with a COOKIE ACK chunk after building a TCB and moving to
622 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
623 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
624 * chunk MUST be the first chunk in the packet.
626 * IMPLEMENTATION NOTE: An implementation may choose to send the
627 * Communication Up notification to the SCTP user upon reception
628 * of a valid COOKIE ECHO chunk.
630 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
631 * D) Rules for packet carrying a COOKIE ECHO
633 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
634 * Initial Tag received in the INIT ACK.
636 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
639 * (endpoint, asoc, chunk)
642 * (asoc, reply_msg, msg_up, timers, counters)
644 * The return value is the disposition of the chunk.
646 sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
647 const struct sctp_endpoint *ep,
648 const struct sctp_association *asoc,
649 const sctp_subtype_t type, void *arg,
650 sctp_cmd_seq_t *commands)
652 struct sctp_chunk *chunk = arg;
653 struct sctp_association *new_asoc;
654 sctp_init_chunk_t *peer_init;
655 struct sctp_chunk *repl;
656 struct sctp_ulpevent *ev, *ai_ev = NULL;
658 struct sctp_chunk *err_chk_p;
661 /* If the packet is an OOTB packet which is temporarily on the
662 * control endpoint, respond with an ABORT.
664 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
665 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
666 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
669 /* Make sure that the COOKIE_ECHO chunk has a valid length.
670 * In this case, we check that we have enough for at least a
671 * chunk header. More detailed verification is done
672 * in sctp_unpack_cookie().
674 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
675 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
677 /* If the endpoint is not listening or if the number of associations
678 * on the TCP-style socket exceed the max backlog, respond with an
682 if (!sctp_sstate(sk, LISTENING) ||
683 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
684 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
686 /* "Decode" the chunk. We have no optional parameters so we
689 chunk->subh.cookie_hdr =
690 (struct sctp_signed_cookie *)chunk->skb->data;
691 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
692 sizeof(sctp_chunkhdr_t)))
695 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
696 * "Z" will reply with a COOKIE ACK chunk after building a TCB
697 * and moving to the ESTABLISHED state.
699 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
703 * If the re-build failed, what is the proper error path
706 * [We should abort the association. --piggy]
709 /* FIXME: Several errors are possible. A bad cookie should
710 * be silently discarded, but think about logging it too.
713 case -SCTP_IERROR_NOMEM:
716 case -SCTP_IERROR_STALE_COOKIE:
717 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
719 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
721 case -SCTP_IERROR_BAD_SIG:
723 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
728 /* Delay state machine commands until later.
730 * Re-build the bind address for the association is done in
731 * the sctp_unpack_cookie() already.
733 /* This is a brand-new association, so these are not yet side
734 * effects--it is safe to run them here.
736 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
738 if (!sctp_process_init(new_asoc, chunk,
739 &chunk->subh.cookie_hdr->c.peer_addr,
740 peer_init, GFP_ATOMIC))
743 /* SCTP-AUTH: Now that we've populate required fields in
744 * sctp_process_init, set up the assocaition shared keys as
745 * necessary so that we can potentially authenticate the ACK
747 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
751 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
752 * is supposed to be authenticated and we have to do delayed
753 * authentication. We've just recreated the association using
754 * the information in the cookie and now it's much easier to
755 * do the authentication.
757 if (chunk->auth_chunk) {
758 struct sctp_chunk auth;
761 /* Make sure that we and the peer are AUTH capable */
762 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
763 sctp_association_free(new_asoc);
764 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
767 /* set-up our fake chunk so that we can process it */
768 auth.skb = chunk->auth_chunk;
769 auth.asoc = chunk->asoc;
770 auth.sctp_hdr = chunk->sctp_hdr;
771 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
772 sizeof(sctp_chunkhdr_t));
773 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
774 auth.transport = chunk->transport;
776 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
777 if (ret != SCTP_IERROR_NO_ERROR) {
778 sctp_association_free(new_asoc);
779 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
783 repl = sctp_make_cookie_ack(new_asoc, chunk);
787 /* RFC 2960 5.1 Normal Establishment of an Association
789 * D) IMPLEMENTATION NOTE: An implementation may choose to
790 * send the Communication Up notification to the SCTP user
791 * upon reception of a valid COOKIE ECHO chunk.
793 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
794 new_asoc->c.sinit_num_ostreams,
795 new_asoc->c.sinit_max_instreams,
800 /* Sockets API Draft Section 5.3.1.6
801 * When a peer sends a Adaptation Layer Indication parameter , SCTP
802 * delivers this notification to inform the application that of the
803 * peers requested adaptation layer.
805 if (new_asoc->peer.adaptation_ind) {
806 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
812 /* Add all the state machine commands now since we've created
813 * everything. This way we don't introduce memory corruptions
814 * during side-effect processing and correclty count established
817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
818 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
819 SCTP_STATE(SCTP_STATE_ESTABLISHED));
820 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
821 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
822 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
824 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
825 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
826 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
828 /* This will send the COOKIE ACK */
829 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
831 /* Queue the ASSOC_CHANGE event */
832 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
834 /* Send up the Adaptation Layer Indication event */
836 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
837 SCTP_ULPEVENT(ai_ev));
839 return SCTP_DISPOSITION_CONSUME;
842 sctp_ulpevent_free(ev);
844 sctp_chunk_free(repl);
846 sctp_association_free(new_asoc);
848 return SCTP_DISPOSITION_NOMEM;
852 * Respond to a normal COOKIE ACK chunk.
853 * We are the side that is being asked for an association.
855 * RFC 2960 5.1 Normal Establishment of an Association
857 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
858 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
859 * timer. It may also notify its ULP about the successful
860 * establishment of the association with a Communication Up
861 * notification (see Section 10).
865 * (endpoint, asoc, chunk)
868 * (asoc, reply_msg, msg_up, timers, counters)
870 * The return value is the disposition of the chunk.
872 sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
873 const struct sctp_endpoint *ep,
874 const struct sctp_association *asoc,
875 const sctp_subtype_t type, void *arg,
876 sctp_cmd_seq_t *commands)
878 struct sctp_chunk *chunk = arg;
879 struct sctp_ulpevent *ev;
881 if (!sctp_vtag_verify(chunk, asoc))
882 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
884 /* Verify that the chunk length for the COOKIE-ACK is OK.
885 * If we don't do this, any bundled chunks may be junked.
887 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
888 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
891 /* Reset init error count upon receipt of COOKIE-ACK,
892 * to avoid problems with the managemement of this
893 * counter in stale cookie situations when a transition back
894 * from the COOKIE-ECHOED state to the COOKIE-WAIT
895 * state is performed.
897 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
899 /* RFC 2960 5.1 Normal Establishment of an Association
901 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
902 * from the COOKIE-ECHOED state to the ESTABLISHED state,
903 * stopping the T1-cookie timer.
905 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
906 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
907 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
908 SCTP_STATE(SCTP_STATE_ESTABLISHED));
909 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
910 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
911 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
912 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
913 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
914 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
916 /* It may also notify its ULP about the successful
917 * establishment of the association with a Communication Up
918 * notification (see Section 10).
920 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
921 0, asoc->c.sinit_num_ostreams,
922 asoc->c.sinit_max_instreams,
928 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
930 /* Sockets API Draft Section 5.3.1.6
931 * When a peer sends a Adaptation Layer Indication parameter , SCTP
932 * delivers this notification to inform the application that of the
933 * peers requested adaptation layer.
935 if (asoc->peer.adaptation_ind) {
936 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
940 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
944 return SCTP_DISPOSITION_CONSUME;
946 return SCTP_DISPOSITION_NOMEM;
949 /* Generate and sendout a heartbeat packet. */
950 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
951 const struct sctp_association *asoc,
952 const sctp_subtype_t type,
954 sctp_cmd_seq_t *commands)
956 struct sctp_transport *transport = (struct sctp_transport *) arg;
957 struct sctp_chunk *reply;
959 /* Send a heartbeat to our peer. */
960 reply = sctp_make_heartbeat(asoc, transport);
962 return SCTP_DISPOSITION_NOMEM;
964 /* Set rto_pending indicating that an RTT measurement
965 * is started with this heartbeat chunk.
967 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
968 SCTP_TRANSPORT(transport));
970 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
971 return SCTP_DISPOSITION_CONSUME;
974 /* Generate a HEARTBEAT packet on the given transport. */
975 sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
976 const struct sctp_endpoint *ep,
977 const struct sctp_association *asoc,
978 const sctp_subtype_t type,
980 sctp_cmd_seq_t *commands)
982 struct sctp_transport *transport = (struct sctp_transport *) arg;
984 if (asoc->overall_error_count >= asoc->max_retrans) {
985 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
986 SCTP_ERROR(ETIMEDOUT));
987 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
988 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
989 SCTP_PERR(SCTP_ERROR_NO_ERROR));
990 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
991 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
992 return SCTP_DISPOSITION_DELETE_TCB;
996 * The Sender-specific Heartbeat Info field should normally include
997 * information about the sender's current time when this HEARTBEAT
998 * chunk is sent and the destination transport address to which this
999 * HEARTBEAT is sent (see Section 8.3).
1002 if (transport->param_flags & SPP_HB_ENABLE) {
1003 if (SCTP_DISPOSITION_NOMEM ==
1004 sctp_sf_heartbeat(ep, asoc, type, arg,
1006 return SCTP_DISPOSITION_NOMEM;
1008 /* Set transport error counter and association error counter
1009 * when sending heartbeat.
1011 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1012 SCTP_TRANSPORT(transport));
1014 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1015 SCTP_TRANSPORT(transport));
1016 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1017 SCTP_TRANSPORT(transport));
1019 return SCTP_DISPOSITION_CONSUME;
1023 * Process an heartbeat request.
1025 * Section: 8.3 Path Heartbeat
1026 * The receiver of the HEARTBEAT should immediately respond with a
1027 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1028 * from the received HEARTBEAT chunk.
1030 * Verification Tag: 8.5 Verification Tag [Normal verification]
1031 * When receiving an SCTP packet, the endpoint MUST ensure that the
1032 * value in the Verification Tag field of the received SCTP packet
1033 * matches its own Tag. If the received Verification Tag value does not
1034 * match the receiver's own tag value, the receiver shall silently
1035 * discard the packet and shall not process it any further except for
1036 * those cases listed in Section 8.5.1 below.
1039 * (endpoint, asoc, chunk)
1042 * (asoc, reply_msg, msg_up, timers, counters)
1044 * The return value is the disposition of the chunk.
1046 sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1047 const struct sctp_endpoint *ep,
1048 const struct sctp_association *asoc,
1049 const sctp_subtype_t type,
1051 sctp_cmd_seq_t *commands)
1053 sctp_paramhdr_t *param_hdr;
1054 struct sctp_chunk *chunk = arg;
1055 struct sctp_chunk *reply;
1058 if (!sctp_vtag_verify(chunk, asoc))
1059 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1061 /* Make sure that the HEARTBEAT chunk has a valid length. */
1062 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1063 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1066 /* 8.3 The receiver of the HEARTBEAT should immediately
1067 * respond with a HEARTBEAT ACK that contains the Heartbeat
1068 * Information field copied from the received HEARTBEAT chunk.
1070 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1071 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
1072 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1074 if (ntohs(param_hdr->length) > paylen)
1075 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1076 param_hdr, commands);
1078 if (!pskb_pull(chunk->skb, paylen))
1081 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1085 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1086 return SCTP_DISPOSITION_CONSUME;
1089 return SCTP_DISPOSITION_NOMEM;
1093 * Process the returning HEARTBEAT ACK.
1095 * Section: 8.3 Path Heartbeat
1096 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1097 * should clear the error counter of the destination transport
1098 * address to which the HEARTBEAT was sent, and mark the destination
1099 * transport address as active if it is not so marked. The endpoint may
1100 * optionally report to the upper layer when an inactive destination
1101 * address is marked as active due to the reception of the latest
1102 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1103 * clear the association overall error count as well (as defined
1106 * The receiver of the HEARTBEAT ACK should also perform an RTT
1107 * measurement for that destination transport address using the time
1108 * value carried in the HEARTBEAT ACK chunk.
1110 * Verification Tag: 8.5 Verification Tag [Normal verification]
1113 * (endpoint, asoc, chunk)
1116 * (asoc, reply_msg, msg_up, timers, counters)
1118 * The return value is the disposition of the chunk.
1120 sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1121 const struct sctp_endpoint *ep,
1122 const struct sctp_association *asoc,
1123 const sctp_subtype_t type,
1125 sctp_cmd_seq_t *commands)
1127 struct sctp_chunk *chunk = arg;
1128 union sctp_addr from_addr;
1129 struct sctp_transport *link;
1130 sctp_sender_hb_info_t *hbinfo;
1131 unsigned long max_interval;
1133 if (!sctp_vtag_verify(chunk, asoc))
1134 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1136 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1137 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1138 sizeof(sctp_sender_hb_info_t)))
1139 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1142 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1143 /* Make sure that the length of the parameter is what we expect */
1144 if (ntohs(hbinfo->param_hdr.length) !=
1145 sizeof(sctp_sender_hb_info_t)) {
1146 return SCTP_DISPOSITION_DISCARD;
1149 from_addr = hbinfo->daddr;
1150 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1152 /* This should never happen, but lets log it if so. */
1153 if (unlikely(!link)) {
1154 if (from_addr.sa.sa_family == AF_INET6) {
1155 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1158 &from_addr.v6.sin6_addr);
1160 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1163 &from_addr.v4.sin_addr.s_addr);
1165 return SCTP_DISPOSITION_DISCARD;
1168 /* Validate the 64-bit random nonce. */
1169 if (hbinfo->hb_nonce != link->hb_nonce)
1170 return SCTP_DISPOSITION_DISCARD;
1172 max_interval = link->hbinterval + link->rto;
1174 /* Check if the timestamp looks valid. */
1175 if (time_after(hbinfo->sent_at, jiffies) ||
1176 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1177 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1178 "for transport:%p\n", __func__, link);
1180 return SCTP_DISPOSITION_DISCARD;
1183 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1184 * the HEARTBEAT should clear the error counter of the
1185 * destination transport address to which the HEARTBEAT was
1186 * sent and mark the destination transport address as active if
1187 * it is not so marked.
1189 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1191 return SCTP_DISPOSITION_CONSUME;
1194 /* Helper function to send out an abort for the restart
1197 static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1198 struct sctp_chunk *init,
1199 sctp_cmd_seq_t *commands)
1202 struct sctp_packet *pkt;
1203 union sctp_addr_param *addrparm;
1204 struct sctp_errhdr *errhdr;
1205 struct sctp_endpoint *ep;
1206 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1207 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1209 /* Build the error on the stack. We are way to malloc crazy
1210 * throughout the code today.
1212 errhdr = (struct sctp_errhdr *)buffer;
1213 addrparm = (union sctp_addr_param *)errhdr->variable;
1215 /* Copy into a parm format. */
1216 len = af->to_addr_param(ssa, addrparm);
1217 len += sizeof(sctp_errhdr_t);
1219 errhdr->cause = SCTP_ERROR_RESTART;
1220 errhdr->length = htons(len);
1222 /* Assign to the control socket. */
1223 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1225 /* Association is NULL since this may be a restart attack and we
1226 * want to send back the attacker's vtag.
1228 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1232 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1234 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1236 /* Discard the rest of the inbound packet. */
1237 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1240 /* Even if there is no memory, treat as a failure so
1241 * the packet will get dropped.
1246 static bool list_has_sctp_addr(const struct list_head *list,
1247 union sctp_addr *ipaddr)
1249 struct sctp_transport *addr;
1251 list_for_each_entry(addr, list, transports) {
1252 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1258 /* A restart is occurring, check to make sure no new addresses
1259 * are being added as we may be under a takeover attack.
1261 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1262 const struct sctp_association *asoc,
1263 struct sctp_chunk *init,
1264 sctp_cmd_seq_t *commands)
1266 struct net *net = sock_net(new_asoc->base.sk);
1267 struct sctp_transport *new_addr;
1270 /* Implementor's Guide - Section 5.2.2
1272 * Before responding the endpoint MUST check to see if the
1273 * unexpected INIT adds new addresses to the association. If new
1274 * addresses are added to the association, the endpoint MUST respond
1278 /* Search through all current addresses and make sure
1279 * we aren't adding any new ones.
1281 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1283 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1284 &new_addr->ipaddr)) {
1285 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
1292 /* Return success if all addresses were found. */
1296 /* Populate the verification/tie tags based on overlapping INIT
1299 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1301 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1302 const struct sctp_association *asoc)
1304 switch (asoc->state) {
1306 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1308 case SCTP_STATE_COOKIE_WAIT:
1309 new_asoc->c.my_vtag = asoc->c.my_vtag;
1310 new_asoc->c.my_ttag = asoc->c.my_vtag;
1311 new_asoc->c.peer_ttag = 0;
1314 case SCTP_STATE_COOKIE_ECHOED:
1315 new_asoc->c.my_vtag = asoc->c.my_vtag;
1316 new_asoc->c.my_ttag = asoc->c.my_vtag;
1317 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1320 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1321 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1324 new_asoc->c.my_ttag = asoc->c.my_vtag;
1325 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1329 /* Other parameters for the endpoint SHOULD be copied from the
1330 * existing parameters of the association (e.g. number of
1331 * outbound streams) into the INIT ACK and cookie.
1333 new_asoc->rwnd = asoc->rwnd;
1334 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1335 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1336 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1340 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1343 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1345 * Returns value representing action to be taken. These action values
1346 * correspond to Action/Description values in RFC 2960, Table 2.
1348 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1349 const struct sctp_association *asoc)
1351 /* In this case, the peer may have restarted. */
1352 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1353 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1354 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1355 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1358 /* Collision case B. */
1359 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1360 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1361 (0 == asoc->c.peer_vtag))) {
1365 /* Collision case D. */
1366 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1367 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1370 /* Collision case C. */
1371 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1372 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1373 (0 == new_asoc->c.my_ttag) &&
1374 (0 == new_asoc->c.peer_ttag))
1377 /* No match to any of the special cases; discard this packet. */
1381 /* Common helper routine for both duplicate and simulataneous INIT
1384 static sctp_disposition_t sctp_sf_do_unexpected_init(
1386 const struct sctp_endpoint *ep,
1387 const struct sctp_association *asoc,
1388 const sctp_subtype_t type,
1389 void *arg, sctp_cmd_seq_t *commands)
1391 sctp_disposition_t retval;
1392 struct sctp_chunk *chunk = arg;
1393 struct sctp_chunk *repl;
1394 struct sctp_association *new_asoc;
1395 struct sctp_chunk *err_chunk;
1396 struct sctp_packet *packet;
1397 sctp_unrecognized_param_t *unk_param;
1401 * An endpoint MUST NOT bundle INIT, INIT ACK or
1402 * SHUTDOWN COMPLETE with any other chunks.
1405 * Furthermore, we require that the receiver of an INIT chunk MUST
1406 * enforce these rules by silently discarding an arriving packet
1407 * with an INIT chunk that is bundled with other chunks.
1409 if (!chunk->singleton)
1410 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1412 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1415 if (chunk->sctp_hdr->vtag != 0)
1416 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1418 /* Make sure that the INIT chunk has a valid length.
1419 * In this case, we generate a protocol violation since we have
1420 * an association established.
1422 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1423 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1425 /* Grab the INIT header. */
1426 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1428 /* Tag the variable length parameters. */
1429 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1431 /* Verify the INIT chunk before processing it. */
1433 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1434 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1436 /* This chunk contains fatal error. It is to be discarded.
1437 * Send an ABORT, with causes if there is any.
1440 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1441 (__u8 *)(err_chunk->chunk_hdr) +
1442 sizeof(sctp_chunkhdr_t),
1443 ntohs(err_chunk->chunk_hdr->length) -
1444 sizeof(sctp_chunkhdr_t));
1447 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1448 SCTP_PACKET(packet));
1449 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1450 retval = SCTP_DISPOSITION_CONSUME;
1452 retval = SCTP_DISPOSITION_NOMEM;
1456 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1462 * Other parameters for the endpoint SHOULD be copied from the
1463 * existing parameters of the association (e.g. number of
1464 * outbound streams) into the INIT ACK and cookie.
1465 * FIXME: We are copying parameters from the endpoint not the
1468 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1472 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1473 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1476 /* In the outbound INIT ACK the endpoint MUST copy its current
1477 * Verification Tag and Peers Verification tag into a reserved
1478 * place (local tie-tag and per tie-tag) within the state cookie.
1480 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1481 (sctp_init_chunk_t *)chunk->chunk_hdr,
1485 /* Make sure no new addresses are being added during the
1486 * restart. Do not do this check for COOKIE-WAIT state,
1487 * since there are no peer addresses to check against.
1488 * Upon return an ABORT will have been sent if needed.
1490 if (!sctp_state(asoc, COOKIE_WAIT)) {
1491 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1493 retval = SCTP_DISPOSITION_CONSUME;
1498 sctp_tietags_populate(new_asoc, asoc);
1500 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1502 /* If there are errors need to be reported for unknown parameters,
1503 * make sure to reserve enough room in the INIT ACK for them.
1507 len = ntohs(err_chunk->chunk_hdr->length) -
1508 sizeof(sctp_chunkhdr_t);
1511 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1515 /* If there are errors need to be reported for unknown parameters,
1516 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1520 /* Get the "Unrecognized parameter" parameter(s) out of the
1521 * ERROR chunk generated by sctp_verify_init(). Since the
1522 * error cause code for "unknown parameter" and the
1523 * "Unrecognized parameter" type is the same, we can
1524 * construct the parameters in INIT ACK by copying the
1525 * ERROR causes over.
1527 unk_param = (sctp_unrecognized_param_t *)
1528 ((__u8 *)(err_chunk->chunk_hdr) +
1529 sizeof(sctp_chunkhdr_t));
1530 /* Replace the cause code with the "Unrecognized parameter"
1533 sctp_addto_chunk(repl, len, unk_param);
1536 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1537 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1540 * Note: After sending out INIT ACK with the State Cookie parameter,
1541 * "Z" MUST NOT allocate any resources for this new association.
1542 * Otherwise, "Z" will be vulnerable to resource attacks.
1544 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1545 retval = SCTP_DISPOSITION_CONSUME;
1550 retval = SCTP_DISPOSITION_NOMEM;
1553 sctp_association_free(new_asoc);
1556 sctp_chunk_free(err_chunk);
1561 * Handle simultaneous INIT.
1562 * This means we started an INIT and then we got an INIT request from
1565 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1566 * This usually indicates an initialization collision, i.e., each
1567 * endpoint is attempting, at about the same time, to establish an
1568 * association with the other endpoint.
1570 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1571 * endpoint MUST respond with an INIT ACK using the same parameters it
1572 * sent in its original INIT chunk (including its Verification Tag,
1573 * unchanged). These original parameters are combined with those from the
1574 * newly received INIT chunk. The endpoint shall also generate a State
1575 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1576 * INIT to calculate the State Cookie.
1578 * After that, the endpoint MUST NOT change its state, the T1-init
1579 * timer shall be left running and the corresponding TCB MUST NOT be
1580 * destroyed. The normal procedures for handling State Cookies when
1581 * a TCB exists will resolve the duplicate INITs to a single association.
1583 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1584 * its Tie-Tags with the Tag information of itself and its peer (see
1585 * section 5.2.2 for a description of the Tie-Tags).
1587 * Verification Tag: Not explicit, but an INIT can not have a valid
1588 * verification tag, so we skip the check.
1591 * (endpoint, asoc, chunk)
1594 * (asoc, reply_msg, msg_up, timers, counters)
1596 * The return value is the disposition of the chunk.
1598 sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1599 const struct sctp_endpoint *ep,
1600 const struct sctp_association *asoc,
1601 const sctp_subtype_t type,
1603 sctp_cmd_seq_t *commands)
1605 /* Call helper to do the real work for both simulataneous and
1606 * duplicate INIT chunk handling.
1608 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1612 * Handle duplicated INIT messages. These are usually delayed
1615 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1616 * COOKIE-ECHOED and COOKIE-WAIT
1618 * Unless otherwise stated, upon reception of an unexpected INIT for
1619 * this association, the endpoint shall generate an INIT ACK with a
1620 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1621 * current Verification Tag and peer's Verification Tag into a reserved
1622 * place within the state cookie. We shall refer to these locations as
1623 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1624 * containing this INIT ACK MUST carry a Verification Tag value equal to
1625 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1626 * MUST contain a new Initiation Tag (randomly generated see Section
1627 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1628 * existing parameters of the association (e.g. number of outbound
1629 * streams) into the INIT ACK and cookie.
1631 * After sending out the INIT ACK, the endpoint shall take no further
1632 * actions, i.e., the existing association, including its current state,
1633 * and the corresponding TCB MUST NOT be changed.
1635 * Note: Only when a TCB exists and the association is not in a COOKIE-
1636 * WAIT state are the Tie-Tags populated. For a normal association INIT
1637 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1638 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1639 * State Cookie are populated as specified in section 5.2.1.
1641 * Verification Tag: Not specified, but an INIT has no way of knowing
1642 * what the verification tag could be, so we ignore it.
1645 * (endpoint, asoc, chunk)
1648 * (asoc, reply_msg, msg_up, timers, counters)
1650 * The return value is the disposition of the chunk.
1652 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1653 const struct sctp_endpoint *ep,
1654 const struct sctp_association *asoc,
1655 const sctp_subtype_t type,
1657 sctp_cmd_seq_t *commands)
1659 /* Call helper to do the real work for both simulataneous and
1660 * duplicate INIT chunk handling.
1662 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1667 * Unexpected INIT-ACK handler.
1670 * If an INIT ACK received by an endpoint in any state other than the
1671 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1672 * An unexpected INIT ACK usually indicates the processing of an old or
1673 * duplicated INIT chunk.
1675 sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1676 const struct sctp_endpoint *ep,
1677 const struct sctp_association *asoc,
1678 const sctp_subtype_t type,
1679 void *arg, sctp_cmd_seq_t *commands)
1681 /* Per the above section, we'll discard the chunk if we have an
1682 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1684 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
1685 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
1687 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
1690 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1693 * A) In this case, the peer may have restarted.
1695 static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1696 const struct sctp_endpoint *ep,
1697 const struct sctp_association *asoc,
1698 struct sctp_chunk *chunk,
1699 sctp_cmd_seq_t *commands,
1700 struct sctp_association *new_asoc)
1702 sctp_init_chunk_t *peer_init;
1703 struct sctp_ulpevent *ev;
1704 struct sctp_chunk *repl;
1705 struct sctp_chunk *err;
1706 sctp_disposition_t disposition;
1708 /* new_asoc is a brand-new association, so these are not yet
1709 * side effects--it is safe to run them here.
1711 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1713 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1717 /* Make sure no new addresses are being added during the
1718 * restart. Though this is a pretty complicated attack
1719 * since you'd have to get inside the cookie.
1721 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1722 return SCTP_DISPOSITION_CONSUME;
1725 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1726 * the peer has restarted (Action A), it MUST NOT setup a new
1727 * association but instead resend the SHUTDOWN ACK and send an ERROR
1728 * chunk with a "Cookie Received while Shutting Down" error cause to
1731 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1732 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1733 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1735 if (SCTP_DISPOSITION_NOMEM == disposition)
1738 err = sctp_make_op_error(asoc, chunk,
1739 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1742 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1745 return SCTP_DISPOSITION_CONSUME;
1748 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1749 * data. Consider the optional choice of resending of this data.
1751 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1752 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1753 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1754 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1756 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1757 * and ASCONF-ACK cache.
1759 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1760 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1761 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1763 repl = sctp_make_cookie_ack(new_asoc, chunk);
1767 /* Report association restart to upper layer. */
1768 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1769 new_asoc->c.sinit_num_ostreams,
1770 new_asoc->c.sinit_max_instreams,
1775 /* Update the content of current association. */
1776 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1777 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1778 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1779 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1780 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1781 return SCTP_DISPOSITION_CONSUME;
1784 sctp_chunk_free(repl);
1786 return SCTP_DISPOSITION_NOMEM;
1789 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1792 * B) In this case, both sides may be attempting to start an association
1793 * at about the same time but the peer endpoint started its INIT
1794 * after responding to the local endpoint's INIT
1796 /* This case represents an initialization collision. */
1797 static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1798 const struct sctp_endpoint *ep,
1799 const struct sctp_association *asoc,
1800 struct sctp_chunk *chunk,
1801 sctp_cmd_seq_t *commands,
1802 struct sctp_association *new_asoc)
1804 sctp_init_chunk_t *peer_init;
1805 struct sctp_chunk *repl;
1807 /* new_asoc is a brand-new association, so these are not yet
1808 * side effects--it is safe to run them here.
1810 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1811 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1815 /* Update the content of current association. */
1816 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1818 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1819 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1820 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1822 repl = sctp_make_cookie_ack(new_asoc, chunk);
1826 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1828 /* RFC 2960 5.1 Normal Establishment of an Association
1830 * D) IMPLEMENTATION NOTE: An implementation may choose to
1831 * send the Communication Up notification to the SCTP user
1832 * upon reception of a valid COOKIE ECHO chunk.
1834 * Sadly, this needs to be implemented as a side-effect, because
1835 * we are not guaranteed to have set the association id of the real
1836 * association and so these notifications need to be delayed until
1837 * the association id is allocated.
1840 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1842 /* Sockets API Draft Section 5.3.1.6
1843 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1844 * delivers this notification to inform the application that of the
1845 * peers requested adaptation layer.
1847 * This also needs to be done as a side effect for the same reason as
1850 if (asoc->peer.adaptation_ind)
1851 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1853 return SCTP_DISPOSITION_CONSUME;
1856 return SCTP_DISPOSITION_NOMEM;
1859 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1862 * C) In this case, the local endpoint's cookie has arrived late.
1863 * Before it arrived, the local endpoint sent an INIT and received an
1864 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1865 * but a new tag of its own.
1867 /* This case represents an initialization collision. */
1868 static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1869 const struct sctp_endpoint *ep,
1870 const struct sctp_association *asoc,
1871 struct sctp_chunk *chunk,
1872 sctp_cmd_seq_t *commands,
1873 struct sctp_association *new_asoc)
1875 /* The cookie should be silently discarded.
1876 * The endpoint SHOULD NOT change states and should leave
1877 * any timers running.
1879 return SCTP_DISPOSITION_DISCARD;
1882 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1886 * D) When both local and remote tags match the endpoint should always
1887 * enter the ESTABLISHED state, if it has not already done so.
1889 /* This case represents an initialization collision. */
1890 static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1891 const struct sctp_endpoint *ep,
1892 const struct sctp_association *asoc,
1893 struct sctp_chunk *chunk,
1894 sctp_cmd_seq_t *commands,
1895 struct sctp_association *new_asoc)
1897 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1898 struct sctp_chunk *repl;
1900 /* Clarification from Implementor's Guide:
1901 * D) When both local and remote tags match the endpoint should
1902 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1903 * It should stop any cookie timer that may be running and send
1907 /* Don't accidentally move back into established state. */
1908 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1909 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1910 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1911 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1912 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1913 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1914 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1917 /* RFC 2960 5.1 Normal Establishment of an Association
1919 * D) IMPLEMENTATION NOTE: An implementation may choose
1920 * to send the Communication Up notification to the
1921 * SCTP user upon reception of a valid COOKIE
1924 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1926 asoc->c.sinit_num_ostreams,
1927 asoc->c.sinit_max_instreams,
1932 /* Sockets API Draft Section 5.3.1.6
1933 * When a peer sends a Adaptation Layer Indication parameter,
1934 * SCTP delivers this notification to inform the application
1935 * that of the peers requested adaptation layer.
1937 if (asoc->peer.adaptation_ind) {
1938 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1946 repl = sctp_make_cookie_ack(new_asoc, chunk);
1950 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1953 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1956 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1957 SCTP_ULPEVENT(ai_ev));
1959 return SCTP_DISPOSITION_CONSUME;
1963 sctp_ulpevent_free(ai_ev);
1965 sctp_ulpevent_free(ev);
1966 return SCTP_DISPOSITION_NOMEM;
1970 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1971 * chunk was retransmitted and then delayed in the network.
1973 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1975 * Verification Tag: None. Do cookie validation.
1978 * (endpoint, asoc, chunk)
1981 * (asoc, reply_msg, msg_up, timers, counters)
1983 * The return value is the disposition of the chunk.
1985 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
1986 const struct sctp_endpoint *ep,
1987 const struct sctp_association *asoc,
1988 const sctp_subtype_t type,
1990 sctp_cmd_seq_t *commands)
1992 sctp_disposition_t retval;
1993 struct sctp_chunk *chunk = arg;
1994 struct sctp_association *new_asoc;
1997 struct sctp_chunk *err_chk_p;
1999 /* Make sure that the chunk has a valid length from the protocol
2000 * perspective. In this case check to make sure we have at least
2001 * enough for the chunk header. Cookie length verification is
2004 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2005 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2008 /* "Decode" the chunk. We have no optional parameters so we
2009 * are in good shape.
2011 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2012 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2013 sizeof(sctp_chunkhdr_t)))
2016 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2017 * of a duplicate COOKIE ECHO match the Verification Tags of the
2018 * current association, consider the State Cookie valid even if
2019 * the lifespan is exceeded.
2021 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2025 * If the re-build failed, what is the proper error path
2028 * [We should abort the association. --piggy]
2031 /* FIXME: Several errors are possible. A bad cookie should
2032 * be silently discarded, but think about logging it too.
2035 case -SCTP_IERROR_NOMEM:
2038 case -SCTP_IERROR_STALE_COOKIE:
2039 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2041 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2042 case -SCTP_IERROR_BAD_SIG:
2044 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2048 /* Compare the tie_tag in cookie with the verification tag of
2049 * current association.
2051 action = sctp_tietags_compare(new_asoc, asoc);
2054 case 'A': /* Association restart. */
2055 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2059 case 'B': /* Collision case B. */
2060 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2064 case 'C': /* Collision case C. */
2065 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2069 case 'D': /* Collision case D. */
2070 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2074 default: /* Discard packet for all others. */
2075 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2079 /* Delete the tempory new association. */
2080 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2081 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2083 /* Restore association pointer to provide SCTP command interpeter
2084 * with a valid context in case it needs to manipulate
2086 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2087 SCTP_ASOC((struct sctp_association *)asoc));
2092 return SCTP_DISPOSITION_NOMEM;
2096 * Process an ABORT. (SHUTDOWN-PENDING state)
2098 * See sctp_sf_do_9_1_abort().
2100 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2102 const struct sctp_endpoint *ep,
2103 const struct sctp_association *asoc,
2104 const sctp_subtype_t type,
2106 sctp_cmd_seq_t *commands)
2108 struct sctp_chunk *chunk = arg;
2110 if (!sctp_vtag_verify_either(chunk, asoc))
2111 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2113 /* Make sure that the ABORT chunk has a valid length.
2114 * Since this is an ABORT chunk, we have to discard it
2115 * because of the following text:
2116 * RFC 2960, Section 3.3.7
2117 * If an endpoint receives an ABORT with a format error or for an
2118 * association that doesn't exist, it MUST silently discard it.
2119 * Because the length is "invalid", we can't really discard just
2120 * as we do not know its true length. So, to be safe, discard the
2123 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2124 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2126 /* ADD-IP: Special case for ABORT chunks
2127 * F4) One special consideration is that ABORT Chunks arriving
2128 * destined to the IP address being deleted MUST be
2129 * ignored (see Section 5.3.1 for further details).
2131 if (SCTP_ADDR_DEL ==
2132 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2133 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2135 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2139 * Process an ABORT. (SHUTDOWN-SENT state)
2141 * See sctp_sf_do_9_1_abort().
2143 sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2144 const struct sctp_endpoint *ep,
2145 const struct sctp_association *asoc,
2146 const sctp_subtype_t type,
2148 sctp_cmd_seq_t *commands)
2150 struct sctp_chunk *chunk = arg;
2152 if (!sctp_vtag_verify_either(chunk, asoc))
2153 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2155 /* Make sure that the ABORT chunk has a valid length.
2156 * Since this is an ABORT chunk, we have to discard it
2157 * because of the following text:
2158 * RFC 2960, Section 3.3.7
2159 * If an endpoint receives an ABORT with a format error or for an
2160 * association that doesn't exist, it MUST silently discard it.
2161 * Because the length is "invalid", we can't really discard just
2162 * as we do not know its true length. So, to be safe, discard the
2165 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2166 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2168 /* ADD-IP: Special case for ABORT chunks
2169 * F4) One special consideration is that ABORT Chunks arriving
2170 * destined to the IP address being deleted MUST be
2171 * ignored (see Section 5.3.1 for further details).
2173 if (SCTP_ADDR_DEL ==
2174 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2175 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2177 /* Stop the T2-shutdown timer. */
2178 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2179 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2181 /* Stop the T5-shutdown guard timer. */
2182 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2183 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2185 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2189 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2191 * See sctp_sf_do_9_1_abort().
2193 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2195 const struct sctp_endpoint *ep,
2196 const struct sctp_association *asoc,
2197 const sctp_subtype_t type,
2199 sctp_cmd_seq_t *commands)
2201 /* The same T2 timer, so we should be able to use
2202 * common function with the SHUTDOWN-SENT state.
2204 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2208 * Handle an Error received in COOKIE_ECHOED state.
2210 * Only handle the error type of stale COOKIE Error, the other errors will
2214 * (endpoint, asoc, chunk)
2217 * (asoc, reply_msg, msg_up, timers, counters)
2219 * The return value is the disposition of the chunk.
2221 sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2222 const struct sctp_endpoint *ep,
2223 const struct sctp_association *asoc,
2224 const sctp_subtype_t type,
2226 sctp_cmd_seq_t *commands)
2228 struct sctp_chunk *chunk = arg;
2231 if (!sctp_vtag_verify(chunk, asoc))
2232 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2234 /* Make sure that the ERROR chunk has a valid length.
2235 * The parameter walking depends on this as well.
2237 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2238 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2241 /* Process the error here */
2242 /* FUTURE FIXME: When PR-SCTP related and other optional
2243 * parms are emitted, this will have to change to handle multiple
2246 sctp_walk_errors(err, chunk->chunk_hdr) {
2247 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2248 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2252 /* It is possible to have malformed error causes, and that
2253 * will cause us to end the walk early. However, since
2254 * we are discarding the packet, there should be no adverse
2257 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2261 * Handle a Stale COOKIE Error
2263 * Section: 5.2.6 Handle Stale COOKIE Error
2264 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2265 * one of the following three alternatives.
2267 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2268 * Preservative parameter requesting an extension to the lifetime of
2269 * the State Cookie. When calculating the time extension, an
2270 * implementation SHOULD use the RTT information measured based on the
2271 * previous COOKIE ECHO / ERROR exchange, and should add no more
2272 * than 1 second beyond the measured RTT, due to long State Cookie
2273 * lifetimes making the endpoint more subject to a replay attack.
2275 * Verification Tag: Not explicit, but safe to ignore.
2278 * (endpoint, asoc, chunk)
2281 * (asoc, reply_msg, msg_up, timers, counters)
2283 * The return value is the disposition of the chunk.
2285 static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2286 const struct sctp_endpoint *ep,
2287 const struct sctp_association *asoc,
2288 const sctp_subtype_t type,
2290 sctp_cmd_seq_t *commands)
2292 struct sctp_chunk *chunk = arg;
2294 sctp_cookie_preserve_param_t bht;
2296 struct sctp_chunk *reply;
2297 struct sctp_bind_addr *bp;
2298 int attempts = asoc->init_err_counter + 1;
2300 if (attempts > asoc->max_init_attempts) {
2301 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2302 SCTP_ERROR(ETIMEDOUT));
2303 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2304 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2305 return SCTP_DISPOSITION_DELETE_TCB;
2308 err = (sctp_errhdr_t *)(chunk->skb->data);
2310 /* When calculating the time extension, an implementation
2311 * SHOULD use the RTT information measured based on the
2312 * previous COOKIE ECHO / ERROR exchange, and should add no
2313 * more than 1 second beyond the measured RTT, due to long
2314 * State Cookie lifetimes making the endpoint more subject to
2316 * Measure of Staleness's unit is usec. (1/1000000 sec)
2317 * Suggested Cookie Life-span Increment's unit is msec.
2319 * In general, if you use the suggested cookie life, the value
2320 * found in the field of measure of staleness should be doubled
2321 * to give ample time to retransmit the new cookie and thus
2322 * yield a higher probability of success on the reattempt.
2324 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2325 stale = (stale * 2) / 1000;
2327 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2328 bht.param_hdr.length = htons(sizeof(bht));
2329 bht.lifespan_increment = htonl(stale);
2331 /* Build that new INIT chunk. */
2332 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2333 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2337 sctp_addto_chunk(reply, sizeof(bht), &bht);
2339 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2340 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2342 /* Stop pending T3-rtx and heartbeat timers */
2343 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2344 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2346 /* Delete non-primary peer ip addresses since we are transitioning
2347 * back to the COOKIE-WAIT state
2349 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2351 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2354 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2355 SCTP_TRANSPORT(asoc->peer.primary_path));
2357 /* Cast away the const modifier, as we want to just
2358 * rerun it through as a sideffect.
2360 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2362 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2363 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2364 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2365 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2366 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2367 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2369 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2371 return SCTP_DISPOSITION_CONSUME;
2374 return SCTP_DISPOSITION_NOMEM;
2381 * After checking the Verification Tag, the receiving endpoint shall
2382 * remove the association from its record, and shall report the
2383 * termination to its upper layer.
2385 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2386 * B) Rules for packet carrying ABORT:
2388 * - The endpoint shall always fill in the Verification Tag field of the
2389 * outbound packet with the destination endpoint's tag value if it
2392 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2393 * MUST follow the procedure described in Section 8.4.
2395 * - The receiver MUST accept the packet if the Verification Tag
2396 * matches either its own tag, OR the tag of its peer. Otherwise, the
2397 * receiver MUST silently discard the packet and take no further
2401 * (endpoint, asoc, chunk)
2404 * (asoc, reply_msg, msg_up, timers, counters)
2406 * The return value is the disposition of the chunk.
2408 sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2409 const struct sctp_endpoint *ep,
2410 const struct sctp_association *asoc,
2411 const sctp_subtype_t type,
2413 sctp_cmd_seq_t *commands)
2415 struct sctp_chunk *chunk = arg;
2417 if (!sctp_vtag_verify_either(chunk, asoc))
2418 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2420 /* Make sure that the ABORT chunk has a valid length.
2421 * Since this is an ABORT chunk, we have to discard it
2422 * because of the following text:
2423 * RFC 2960, Section 3.3.7
2424 * If an endpoint receives an ABORT with a format error or for an
2425 * association that doesn't exist, it MUST silently discard it.
2426 * Because the length is "invalid", we can't really discard just
2427 * as we do not know its true length. So, to be safe, discard the
2430 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2431 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2433 /* ADD-IP: Special case for ABORT chunks
2434 * F4) One special consideration is that ABORT Chunks arriving
2435 * destined to the IP address being deleted MUST be
2436 * ignored (see Section 5.3.1 for further details).
2438 if (SCTP_ADDR_DEL ==
2439 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2440 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2442 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2445 static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2446 const struct sctp_endpoint *ep,
2447 const struct sctp_association *asoc,
2448 const sctp_subtype_t type,
2450 sctp_cmd_seq_t *commands)
2452 struct sctp_chunk *chunk = arg;
2454 __be16 error = SCTP_ERROR_NO_ERROR;
2456 /* See if we have an error cause code in the chunk. */
2457 len = ntohs(chunk->chunk_hdr->length);
2458 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2461 sctp_walk_errors(err, chunk->chunk_hdr);
2462 if ((void *)err != (void *)chunk->chunk_end)
2463 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2465 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2468 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2469 /* ASSOC_FAILED will DELETE_TCB. */
2470 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2471 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2472 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2474 return SCTP_DISPOSITION_ABORT;
2478 * Process an ABORT. (COOKIE-WAIT state)
2480 * See sctp_sf_do_9_1_abort() above.
2482 sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2483 const struct sctp_endpoint *ep,
2484 const struct sctp_association *asoc,
2485 const sctp_subtype_t type,
2487 sctp_cmd_seq_t *commands)
2489 struct sctp_chunk *chunk = arg;
2491 __be16 error = SCTP_ERROR_NO_ERROR;
2493 if (!sctp_vtag_verify_either(chunk, asoc))
2494 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2496 /* Make sure that the ABORT chunk has a valid length.
2497 * Since this is an ABORT chunk, we have to discard it
2498 * because of the following text:
2499 * RFC 2960, Section 3.3.7
2500 * If an endpoint receives an ABORT with a format error or for an
2501 * association that doesn't exist, it MUST silently discard it.
2502 * Because the length is "invalid", we can't really discard just
2503 * as we do not know its true length. So, to be safe, discard the
2506 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2507 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2509 /* See if we have an error cause code in the chunk. */
2510 len = ntohs(chunk->chunk_hdr->length);
2511 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2512 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2514 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2519 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2521 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2522 const struct sctp_endpoint *ep,
2523 const struct sctp_association *asoc,
2524 const sctp_subtype_t type,
2526 sctp_cmd_seq_t *commands)
2528 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2530 (struct sctp_transport *)arg);
2534 * Process an ABORT. (COOKIE-ECHOED state)
2536 sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2537 const struct sctp_endpoint *ep,
2538 const struct sctp_association *asoc,
2539 const sctp_subtype_t type,
2541 sctp_cmd_seq_t *commands)
2543 /* There is a single T1 timer, so we should be able to use
2544 * common function with the COOKIE-WAIT state.
2546 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2550 * Stop T1 timer and abort association with "INIT failed".
2552 * This is common code called by several sctp_sf_*_abort() functions above.
2554 static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2555 sctp_cmd_seq_t *commands,
2556 __be16 error, int sk_err,
2557 const struct sctp_association *asoc,
2558 struct sctp_transport *transport)
2560 pr_debug("%s: ABORT received (INIT)\n", __func__);
2562 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2563 SCTP_STATE(SCTP_STATE_CLOSED));
2564 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2565 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2566 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2567 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2568 /* CMD_INIT_FAILED will DELETE_TCB. */
2569 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2572 return SCTP_DISPOSITION_ABORT;
2576 * sctp_sf_do_9_2_shut
2579 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2580 * - enter the SHUTDOWN-RECEIVED state,
2582 * - stop accepting new data from its SCTP user
2584 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2585 * that all its outstanding DATA chunks have been received by the
2588 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2589 * send a SHUTDOWN in response to a ULP request. And should discard
2590 * subsequent SHUTDOWN chunks.
2592 * If there are still outstanding DATA chunks left, the SHUTDOWN
2593 * receiver shall continue to follow normal data transmission
2594 * procedures defined in Section 6 until all outstanding DATA chunks
2595 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2596 * new data from its SCTP user.
2598 * Verification Tag: 8.5 Verification Tag [Normal verification]
2601 * (endpoint, asoc, chunk)
2604 * (asoc, reply_msg, msg_up, timers, counters)
2606 * The return value is the disposition of the chunk.
2608 sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2609 const struct sctp_endpoint *ep,
2610 const struct sctp_association *asoc,
2611 const sctp_subtype_t type,
2613 sctp_cmd_seq_t *commands)
2615 struct sctp_chunk *chunk = arg;
2616 sctp_shutdownhdr_t *sdh;
2617 sctp_disposition_t disposition;
2618 struct sctp_ulpevent *ev;
2621 if (!sctp_vtag_verify(chunk, asoc))
2622 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2624 /* Make sure that the SHUTDOWN chunk has a valid length. */
2625 if (!sctp_chunk_length_valid(chunk,
2626 sizeof(struct sctp_shutdown_chunk_t)))
2627 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2630 /* Convert the elaborate header. */
2631 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2632 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2633 chunk->subh.shutdown_hdr = sdh;
2634 ctsn = ntohl(sdh->cum_tsn_ack);
2636 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2637 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2638 asoc->ctsn_ack_point);
2640 return SCTP_DISPOSITION_DISCARD;
2643 /* If Cumulative TSN Ack beyond the max tsn currently
2644 * send, terminating the association and respond to the
2645 * sender with an ABORT.
2647 if (!TSN_lt(ctsn, asoc->next_tsn))
2648 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2650 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2651 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2652 * inform the application that it should cease sending data.
2654 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2656 disposition = SCTP_DISPOSITION_NOMEM;
2659 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2661 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2662 * - enter the SHUTDOWN-RECEIVED state,
2663 * - stop accepting new data from its SCTP user
2665 * [This is implicit in the new state.]
2667 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2668 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2669 disposition = SCTP_DISPOSITION_CONSUME;
2671 if (sctp_outq_is_empty(&asoc->outqueue)) {
2672 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2676 if (SCTP_DISPOSITION_NOMEM == disposition)
2679 /* - verify, by checking the Cumulative TSN Ack field of the
2680 * chunk, that all its outstanding DATA chunks have been
2681 * received by the SHUTDOWN sender.
2683 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2684 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2691 * sctp_sf_do_9_2_shut_ctsn
2693 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2694 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2695 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2696 * MUST be processed.
2698 sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2699 const struct sctp_endpoint *ep,
2700 const struct sctp_association *asoc,
2701 const sctp_subtype_t type,
2703 sctp_cmd_seq_t *commands)
2705 struct sctp_chunk *chunk = arg;
2706 sctp_shutdownhdr_t *sdh;
2709 if (!sctp_vtag_verify(chunk, asoc))
2710 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2712 /* Make sure that the SHUTDOWN chunk has a valid length. */
2713 if (!sctp_chunk_length_valid(chunk,
2714 sizeof(struct sctp_shutdown_chunk_t)))
2715 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2718 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2719 ctsn = ntohl(sdh->cum_tsn_ack);
2721 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2722 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2723 asoc->ctsn_ack_point);
2725 return SCTP_DISPOSITION_DISCARD;
2728 /* If Cumulative TSN Ack beyond the max tsn currently
2729 * send, terminating the association and respond to the
2730 * sender with an ABORT.
2732 if (!TSN_lt(ctsn, asoc->next_tsn))
2733 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2735 /* verify, by checking the Cumulative TSN Ack field of the
2736 * chunk, that all its outstanding DATA chunks have been
2737 * received by the SHUTDOWN sender.
2739 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2740 SCTP_BE32(sdh->cum_tsn_ack));
2742 return SCTP_DISPOSITION_CONSUME;
2746 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2747 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2748 * transport addresses (either in the IP addresses or in the INIT chunk)
2749 * that belong to this association, it should discard the INIT chunk and
2750 * retransmit the SHUTDOWN ACK chunk.
2752 sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2753 const struct sctp_endpoint *ep,
2754 const struct sctp_association *asoc,
2755 const sctp_subtype_t type,
2757 sctp_cmd_seq_t *commands)
2759 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2760 struct sctp_chunk *reply;
2762 /* Make sure that the chunk has a valid length */
2763 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2764 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2767 /* Since we are not going to really process this INIT, there
2768 * is no point in verifying chunk boundries. Just generate
2771 reply = sctp_make_shutdown_ack(asoc, chunk);
2775 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2776 * the T2-SHUTDOWN timer.
2778 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2780 /* and restart the T2-shutdown timer. */
2781 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2782 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2784 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2786 return SCTP_DISPOSITION_CONSUME;
2788 return SCTP_DISPOSITION_NOMEM;
2792 * sctp_sf_do_ecn_cwr
2794 * Section: Appendix A: Explicit Congestion Notification
2798 * RFC 2481 details a specific bit for a sender to send in the header of
2799 * its next outbound TCP segment to indicate to its peer that it has
2800 * reduced its congestion window. This is termed the CWR bit. For
2801 * SCTP the same indication is made by including the CWR chunk.
2802 * This chunk contains one data element, i.e. the TSN number that
2803 * was sent in the ECNE chunk. This element represents the lowest
2804 * TSN number in the datagram that was originally marked with the
2807 * Verification Tag: 8.5 Verification Tag [Normal verification]
2809 * (endpoint, asoc, chunk)
2812 * (asoc, reply_msg, msg_up, timers, counters)
2814 * The return value is the disposition of the chunk.
2816 sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2817 const struct sctp_endpoint *ep,
2818 const struct sctp_association *asoc,
2819 const sctp_subtype_t type,
2821 sctp_cmd_seq_t *commands)
2824 struct sctp_chunk *chunk = arg;
2827 if (!sctp_vtag_verify(chunk, asoc))
2828 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2830 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2831 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2834 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2835 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2837 lowest_tsn = ntohl(cwr->lowest_tsn);
2839 /* Does this CWR ack the last sent congestion notification? */
2840 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2841 /* Stop sending ECNE. */
2842 sctp_add_cmd_sf(commands,
2844 SCTP_U32(lowest_tsn));
2846 return SCTP_DISPOSITION_CONSUME;
2852 * Section: Appendix A: Explicit Congestion Notification
2856 * RFC 2481 details a specific bit for a receiver to send back in its
2857 * TCP acknowledgements to notify the sender of the Congestion
2858 * Experienced (CE) bit having arrived from the network. For SCTP this
2859 * same indication is made by including the ECNE chunk. This chunk
2860 * contains one data element, i.e. the lowest TSN associated with the IP
2861 * datagram marked with the CE bit.....
2863 * Verification Tag: 8.5 Verification Tag [Normal verification]
2865 * (endpoint, asoc, chunk)
2868 * (asoc, reply_msg, msg_up, timers, counters)
2870 * The return value is the disposition of the chunk.
2872 sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2873 const struct sctp_endpoint *ep,
2874 const struct sctp_association *asoc,
2875 const sctp_subtype_t type,
2877 sctp_cmd_seq_t *commands)
2879 sctp_ecnehdr_t *ecne;
2880 struct sctp_chunk *chunk = arg;
2882 if (!sctp_vtag_verify(chunk, asoc))
2883 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2885 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2886 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2889 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2890 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2892 /* If this is a newer ECNE than the last CWR packet we sent out */
2893 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2894 SCTP_U32(ntohl(ecne->lowest_tsn)));
2896 return SCTP_DISPOSITION_CONSUME;
2900 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2902 * The SCTP endpoint MUST always acknowledge the reception of each valid
2905 * The guidelines on delayed acknowledgement algorithm specified in
2906 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2907 * acknowledgement SHOULD be generated for at least every second packet
2908 * (not every second DATA chunk) received, and SHOULD be generated within
2909 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2910 * situations it may be beneficial for an SCTP transmitter to be more
2911 * conservative than the algorithms detailed in this document allow.
2912 * However, an SCTP transmitter MUST NOT be more aggressive than the
2913 * following algorithms allow.
2915 * A SCTP receiver MUST NOT generate more than one SACK for every
2916 * incoming packet, other than to update the offered window as the
2917 * receiving application consumes new data.
2919 * Verification Tag: 8.5 Verification Tag [Normal verification]
2922 * (endpoint, asoc, chunk)
2925 * (asoc, reply_msg, msg_up, timers, counters)
2927 * The return value is the disposition of the chunk.
2929 sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2930 const struct sctp_endpoint *ep,
2931 const struct sctp_association *asoc,
2932 const sctp_subtype_t type,
2934 sctp_cmd_seq_t *commands)
2936 struct sctp_chunk *chunk = arg;
2937 sctp_arg_t force = SCTP_NOFORCE();
2940 if (!sctp_vtag_verify(chunk, asoc)) {
2941 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2943 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2946 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2947 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2950 error = sctp_eat_data(asoc, chunk, commands);
2952 case SCTP_IERROR_NO_ERROR:
2954 case SCTP_IERROR_HIGH_TSN:
2955 case SCTP_IERROR_BAD_STREAM:
2956 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2957 goto discard_noforce;
2958 case SCTP_IERROR_DUP_TSN:
2959 case SCTP_IERROR_IGNORE_TSN:
2960 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2962 case SCTP_IERROR_NO_DATA:
2964 case SCTP_IERROR_PROTO_VIOLATION:
2965 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
2966 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
2971 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2972 force = SCTP_FORCE();
2974 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
2975 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2976 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2979 /* If this is the last chunk in a packet, we need to count it
2980 * toward sack generation. Note that we need to SACK every
2981 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2982 * THEM. We elect to NOT generate SACK's if the chunk fails
2983 * the verification tag test.
2985 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2987 * The SCTP endpoint MUST always acknowledge the reception of
2988 * each valid DATA chunk.
2990 * The guidelines on delayed acknowledgement algorithm
2991 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2992 * Specifically, an acknowledgement SHOULD be generated for at
2993 * least every second packet (not every second DATA chunk)
2994 * received, and SHOULD be generated within 200 ms of the
2995 * arrival of any unacknowledged DATA chunk. In some
2996 * situations it may be beneficial for an SCTP transmitter to
2997 * be more conservative than the algorithms detailed in this
2998 * document allow. However, an SCTP transmitter MUST NOT be
2999 * more aggressive than the following algorithms allow.
3001 if (chunk->end_of_packet)
3002 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3004 return SCTP_DISPOSITION_CONSUME;
3007 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3009 * When a packet arrives with duplicate DATA chunk(s) and with
3010 * no new DATA chunk(s), the endpoint MUST immediately send a
3011 * SACK with no delay. If a packet arrives with duplicate
3012 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3013 * MAY immediately send a SACK. Normally receipt of duplicate
3014 * DATA chunks will occur when the original SACK chunk was lost
3015 * and the peer's RTO has expired. The duplicate TSN number(s)
3016 * SHOULD be reported in the SACK as duplicate.
3018 /* In our case, we split the MAY SACK advice up whether or not
3019 * the last chunk is a duplicate.'
3021 if (chunk->end_of_packet)
3022 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3023 return SCTP_DISPOSITION_DISCARD;
3026 if (chunk->end_of_packet)
3027 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3029 return SCTP_DISPOSITION_DISCARD;
3031 return SCTP_DISPOSITION_CONSUME;
3036 * sctp_sf_eat_data_fast_4_4
3039 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3040 * DATA chunks without delay.
3042 * Verification Tag: 8.5 Verification Tag [Normal verification]
3044 * (endpoint, asoc, chunk)
3047 * (asoc, reply_msg, msg_up, timers, counters)
3049 * The return value is the disposition of the chunk.
3051 sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3052 const struct sctp_endpoint *ep,
3053 const struct sctp_association *asoc,
3054 const sctp_subtype_t type,
3056 sctp_cmd_seq_t *commands)
3058 struct sctp_chunk *chunk = arg;
3061 if (!sctp_vtag_verify(chunk, asoc)) {
3062 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3064 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3067 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3068 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3071 error = sctp_eat_data(asoc, chunk, commands);
3073 case SCTP_IERROR_NO_ERROR:
3074 case SCTP_IERROR_HIGH_TSN:
3075 case SCTP_IERROR_DUP_TSN:
3076 case SCTP_IERROR_IGNORE_TSN:
3077 case SCTP_IERROR_BAD_STREAM:
3079 case SCTP_IERROR_NO_DATA:
3081 case SCTP_IERROR_PROTO_VIOLATION:
3082 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3083 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3088 /* Go a head and force a SACK, since we are shutting down. */
3090 /* Implementor's Guide.
3092 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3093 * respond to each received packet containing one or more DATA chunk(s)
3094 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3096 if (chunk->end_of_packet) {
3097 /* We must delay the chunk creation since the cumulative
3098 * TSN has not been updated yet.
3100 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3101 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3102 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3103 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3107 return SCTP_DISPOSITION_CONSUME;
3111 * Section: 6.2 Processing a Received SACK
3112 * D) Any time a SACK arrives, the endpoint performs the following:
3114 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3115 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3116 * increasing, a SACK whose Cumulative TSN Ack is less than the
3117 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3119 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3120 * of bytes still outstanding after processing the Cumulative TSN Ack
3121 * and the Gap Ack Blocks.
3123 * iii) If the SACK is missing a TSN that was previously
3124 * acknowledged via a Gap Ack Block (e.g., the data receiver
3125 * reneged on the data), then mark the corresponding DATA chunk
3126 * as available for retransmit: Mark it as missing for fast
3127 * retransmit as described in Section 7.2.4 and if no retransmit
3128 * timer is running for the destination address to which the DATA
3129 * chunk was originally transmitted, then T3-rtx is started for
3130 * that destination address.
3132 * Verification Tag: 8.5 Verification Tag [Normal verification]
3135 * (endpoint, asoc, chunk)
3138 * (asoc, reply_msg, msg_up, timers, counters)
3140 * The return value is the disposition of the chunk.
3142 sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3143 const struct sctp_endpoint *ep,
3144 const struct sctp_association *asoc,
3145 const sctp_subtype_t type,
3147 sctp_cmd_seq_t *commands)
3149 struct sctp_chunk *chunk = arg;
3150 sctp_sackhdr_t *sackh;
3153 if (!sctp_vtag_verify(chunk, asoc))
3154 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3156 /* Make sure that the SACK chunk has a valid length. */
3157 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3158 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3161 /* Pull the SACK chunk from the data buffer */
3162 sackh = sctp_sm_pull_sack(chunk);
3163 /* Was this a bogus SACK? */
3165 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3166 chunk->subh.sack_hdr = sackh;
3167 ctsn = ntohl(sackh->cum_tsn_ack);
3169 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3170 * Ack Point, then drop the SACK. Since Cumulative TSN
3171 * Ack is monotonically increasing, a SACK whose
3172 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3173 * Point indicates an out-of-order SACK.
3175 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3176 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3177 asoc->ctsn_ack_point);
3179 return SCTP_DISPOSITION_DISCARD;
3182 /* If Cumulative TSN Ack beyond the max tsn currently
3183 * send, terminating the association and respond to the
3184 * sender with an ABORT.
3186 if (!TSN_lt(ctsn, asoc->next_tsn))
3187 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3189 /* Return this SACK for further processing. */
3190 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3192 /* Note: We do the rest of the work on the PROCESS_SACK
3195 return SCTP_DISPOSITION_CONSUME;
3199 * Generate an ABORT in response to a packet.
3201 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3203 * 8) The receiver should respond to the sender of the OOTB packet with
3204 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3205 * MUST fill in the Verification Tag field of the outbound packet
3206 * with the value found in the Verification Tag field of the OOTB
3207 * packet and set the T-bit in the Chunk Flags to indicate that the
3208 * Verification Tag is reflected. After sending this ABORT, the
3209 * receiver of the OOTB packet shall discard the OOTB packet and take
3210 * no further action.
3214 * The return value is the disposition of the chunk.
3216 static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3217 const struct sctp_endpoint *ep,
3218 const struct sctp_association *asoc,
3219 const sctp_subtype_t type,
3221 sctp_cmd_seq_t *commands)
3223 struct sctp_packet *packet = NULL;
3224 struct sctp_chunk *chunk = arg;
3225 struct sctp_chunk *abort;
3227 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3230 /* Make an ABORT. The T bit will be set if the asoc
3233 abort = sctp_make_abort(asoc, chunk, 0);
3235 sctp_ootb_pkt_free(packet);
3236 return SCTP_DISPOSITION_NOMEM;
3239 /* Reflect vtag if T-Bit is set */
3240 if (sctp_test_T_bit(abort))
3241 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3243 /* Set the skb to the belonging sock for accounting. */
3244 abort->skb->sk = ep->base.sk;
3246 sctp_packet_append_chunk(packet, abort);
3248 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3249 SCTP_PACKET(packet));
3251 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3253 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3254 return SCTP_DISPOSITION_CONSUME;
3257 return SCTP_DISPOSITION_NOMEM;
3261 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3262 * event as ULP notification for each cause included in the chunk.
3264 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3266 * The return value is the disposition of the chunk.
3268 sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3269 const struct sctp_endpoint *ep,
3270 const struct sctp_association *asoc,
3271 const sctp_subtype_t type,
3273 sctp_cmd_seq_t *commands)
3275 struct sctp_chunk *chunk = arg;
3278 if (!sctp_vtag_verify(chunk, asoc))
3279 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3281 /* Make sure that the ERROR chunk has a valid length. */
3282 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3283 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3285 sctp_walk_errors(err, chunk->chunk_hdr);
3286 if ((void *)err != (void *)chunk->chunk_end)
3287 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3288 (void *)err, commands);
3290 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3293 return SCTP_DISPOSITION_CONSUME;
3297 * Process an inbound SHUTDOWN ACK.
3300 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3301 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3302 * peer, and remove all record of the association.
3304 * The return value is the disposition.
3306 sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3307 const struct sctp_endpoint *ep,
3308 const struct sctp_association *asoc,
3309 const sctp_subtype_t type,
3311 sctp_cmd_seq_t *commands)
3313 struct sctp_chunk *chunk = arg;
3314 struct sctp_chunk *reply;
3315 struct sctp_ulpevent *ev;
3317 if (!sctp_vtag_verify(chunk, asoc))
3318 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3320 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3321 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3322 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3324 /* 10.2 H) SHUTDOWN COMPLETE notification
3326 * When SCTP completes the shutdown procedures (section 9.2) this
3327 * notification is passed to the upper layer.
3329 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3330 0, 0, 0, NULL, GFP_ATOMIC);
3334 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3335 reply = sctp_make_shutdown_complete(asoc, chunk);
3339 /* Do all the commands now (after allocation), so that we
3340 * have consistent state if memory allocation failes
3342 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3344 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3345 * stop the T2-shutdown timer,
3347 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3348 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3350 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3351 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3353 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3354 SCTP_STATE(SCTP_STATE_CLOSED));
3355 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3356 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3357 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3359 /* ...and remove all record of the association. */
3360 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3361 return SCTP_DISPOSITION_DELETE_TCB;
3364 sctp_ulpevent_free(ev);
3366 return SCTP_DISPOSITION_NOMEM;
3370 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3372 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3373 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3374 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3375 * packet must fill in the Verification Tag field of the outbound
3376 * packet with the Verification Tag received in the SHUTDOWN ACK and
3377 * set the T-bit in the Chunk Flags to indicate that the Verification
3380 * 8) The receiver should respond to the sender of the OOTB packet with
3381 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3382 * MUST fill in the Verification Tag field of the outbound packet
3383 * with the value found in the Verification Tag field of the OOTB
3384 * packet and set the T-bit in the Chunk Flags to indicate that the
3385 * Verification Tag is reflected. After sending this ABORT, the
3386 * receiver of the OOTB packet shall discard the OOTB packet and take
3387 * no further action.
3389 sctp_disposition_t sctp_sf_ootb(struct net *net,
3390 const struct sctp_endpoint *ep,
3391 const struct sctp_association *asoc,
3392 const sctp_subtype_t type,
3394 sctp_cmd_seq_t *commands)
3396 struct sctp_chunk *chunk = arg;
3397 struct sk_buff *skb = chunk->skb;
3398 sctp_chunkhdr_t *ch;
3401 int ootb_shut_ack = 0;
3402 int ootb_cookie_ack = 0;
3404 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3406 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3408 /* Report violation if the chunk is less then minimal */
3409 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3410 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3413 /* Now that we know we at least have a chunk header,
3414 * do things that are type appropriate.
3416 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3419 /* RFC 2960, Section 3.3.7
3420 * Moreover, under any circumstances, an endpoint that
3421 * receives an ABORT MUST NOT respond to that ABORT by
3422 * sending an ABORT of its own.
3424 if (SCTP_CID_ABORT == ch->type)
3425 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3427 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3428 * or a COOKIE ACK the SCTP Packet should be silently
3432 if (SCTP_CID_COOKIE_ACK == ch->type)
3433 ootb_cookie_ack = 1;
3435 if (SCTP_CID_ERROR == ch->type) {
3436 sctp_walk_errors(err, ch) {
3437 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3438 ootb_cookie_ack = 1;
3444 /* Report violation if chunk len overflows */
3445 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3446 if (ch_end > skb_tail_pointer(skb))
3447 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3450 ch = (sctp_chunkhdr_t *) ch_end;
3451 } while (ch_end < skb_tail_pointer(skb));
3454 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3455 else if (ootb_cookie_ack)
3456 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3458 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3462 * Handle an "Out of the blue" SHUTDOWN ACK.
3464 * Section: 8.4 5, sctpimpguide 2.41.
3466 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3467 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3468 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3469 * packet must fill in the Verification Tag field of the outbound
3470 * packet with the Verification Tag received in the SHUTDOWN ACK and
3471 * set the T-bit in the Chunk Flags to indicate that the Verification
3475 * (endpoint, asoc, type, arg, commands)
3478 * (sctp_disposition_t)
3480 * The return value is the disposition of the chunk.
3482 static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3483 const struct sctp_endpoint *ep,
3484 const struct sctp_association *asoc,
3485 const sctp_subtype_t type,
3487 sctp_cmd_seq_t *commands)
3489 struct sctp_packet *packet = NULL;
3490 struct sctp_chunk *chunk = arg;
3491 struct sctp_chunk *shut;
3493 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3496 /* Make an SHUTDOWN_COMPLETE.
3497 * The T bit will be set if the asoc is NULL.
3499 shut = sctp_make_shutdown_complete(asoc, chunk);
3501 sctp_ootb_pkt_free(packet);
3502 return SCTP_DISPOSITION_NOMEM;
3505 /* Reflect vtag if T-Bit is set */
3506 if (sctp_test_T_bit(shut))
3507 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3509 /* Set the skb to the belonging sock for accounting. */
3510 shut->skb->sk = ep->base.sk;
3512 sctp_packet_append_chunk(packet, shut);
3514 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3515 SCTP_PACKET(packet));
3517 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3519 /* If the chunk length is invalid, we don't want to process
3520 * the reset of the packet.
3522 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3523 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3525 /* We need to discard the rest of the packet to prevent
3526 * potential bomming attacks from additional bundled chunks.
3527 * This is documented in SCTP Threats ID.
3529 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3532 return SCTP_DISPOSITION_NOMEM;
3536 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3538 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3539 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3540 * procedures in section 8.4 SHOULD be followed, in other words it
3541 * should be treated as an Out Of The Blue packet.
3542 * [This means that we do NOT check the Verification Tag on these
3546 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3547 const struct sctp_endpoint *ep,
3548 const struct sctp_association *asoc,
3549 const sctp_subtype_t type,
3551 sctp_cmd_seq_t *commands)
3553 struct sctp_chunk *chunk = arg;
3555 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3556 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3557 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3560 /* Although we do have an association in this case, it corresponds
3561 * to a restarted association. So the packet is treated as an OOTB
3562 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3563 * called with a NULL association.
3565 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3567 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3570 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3571 sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3572 const struct sctp_endpoint *ep,
3573 const struct sctp_association *asoc,
3574 const sctp_subtype_t type, void *arg,
3575 sctp_cmd_seq_t *commands)
3577 struct sctp_chunk *chunk = arg;
3578 struct sctp_chunk *asconf_ack = NULL;
3579 struct sctp_paramhdr *err_param = NULL;
3580 sctp_addiphdr_t *hdr;
3581 union sctp_addr_param *addr_param;
3585 if (!sctp_vtag_verify(chunk, asoc)) {
3586 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3588 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3591 /* ADD-IP: Section 4.1.1
3592 * This chunk MUST be sent in an authenticated way by using
3593 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3594 * is received unauthenticated it MUST be silently discarded as
3595 * described in [I-D.ietf-tsvwg-sctp-auth].
3597 if (!net->sctp.addip_noauth && !chunk->auth)
3598 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3600 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3601 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3602 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3605 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3606 serial = ntohl(hdr->serial);
3608 addr_param = (union sctp_addr_param *)hdr->params;
3609 length = ntohs(addr_param->p.length);
3610 if (length < sizeof(sctp_paramhdr_t))
3611 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3612 (void *)addr_param, commands);
3614 /* Verify the ASCONF chunk before processing it. */
3615 if (!sctp_verify_asconf(asoc,
3616 (sctp_paramhdr_t *)((void *)addr_param + length),
3617 (void *)chunk->chunk_end,
3619 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3620 (void *)err_param, commands);
3622 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3623 * the endpoint stored in a new association variable
3624 * 'Peer-Serial-Number'.
3626 if (serial == asoc->peer.addip_serial + 1) {
3627 /* If this is the first instance of ASCONF in the packet,
3628 * we can clean our old ASCONF-ACKs.
3630 if (!chunk->has_asconf)
3631 sctp_assoc_clean_asconf_ack_cache(asoc);
3633 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3634 * expected, process the ASCONF as described below and after
3635 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3636 * the response packet and cache a copy of it (in the event it
3637 * later needs to be retransmitted).
3639 * Essentially, do V1-V5.
3641 asconf_ack = sctp_process_asconf((struct sctp_association *)
3644 return SCTP_DISPOSITION_NOMEM;
3645 } else if (serial < asoc->peer.addip_serial + 1) {
3647 * If the value found in the Sequence Number is less than the
3648 * ('Peer- Sequence-Number' + 1), simply skip to the next
3649 * ASCONF, and include in the outbound response packet
3650 * any previously cached ASCONF-ACK response that was
3651 * sent and saved that matches the Sequence Number of the
3652 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3653 * Chunk exists. This will occur when an older ASCONF
3654 * arrives out of order. In such a case, the receiver
3655 * should skip the ASCONF Chunk and not include ASCONF-ACK
3656 * Chunk for that chunk.
3658 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3660 return SCTP_DISPOSITION_DISCARD;
3662 /* Reset the transport so that we select the correct one
3663 * this time around. This is to make sure that we don't
3664 * accidentally use a stale transport that's been removed.
3666 asconf_ack->transport = NULL;
3668 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3669 * it must be either a stale packet or from an attacker.
3671 return SCTP_DISPOSITION_DISCARD;
3674 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3675 * containing the ASCONF-ACK Chunks MUST be the source address of
3676 * the SCTP packet that held the ASCONF Chunks.
3678 * To do this properly, we'll set the destination address of the chunk
3679 * and at the transmit time, will try look up the transport to use.
3680 * Since ASCONFs may be bundled, the correct transport may not be
3681 * created until we process the entire packet, thus this workaround.
3683 asconf_ack->dest = chunk->source;
3684 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3685 if (asoc->new_transport) {
3686 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3687 ((struct sctp_association *)asoc)->new_transport = NULL;
3690 return SCTP_DISPOSITION_CONSUME;
3694 * ADDIP Section 4.3 General rules for address manipulation
3695 * When building TLV parameters for the ASCONF Chunk that will add or
3696 * delete IP addresses the D0 to D13 rules should be applied:
3698 sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3699 const struct sctp_endpoint *ep,
3700 const struct sctp_association *asoc,
3701 const sctp_subtype_t type, void *arg,
3702 sctp_cmd_seq_t *commands)
3704 struct sctp_chunk *asconf_ack = arg;
3705 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3706 struct sctp_chunk *abort;
3707 struct sctp_paramhdr *err_param = NULL;
3708 sctp_addiphdr_t *addip_hdr;
3709 __u32 sent_serial, rcvd_serial;
3711 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3712 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3714 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3717 /* ADD-IP, Section 4.1.2:
3718 * This chunk MUST be sent in an authenticated way by using
3719 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3720 * is received unauthenticated it MUST be silently discarded as
3721 * described in [I-D.ietf-tsvwg-sctp-auth].
3723 if (!net->sctp.addip_noauth && !asconf_ack->auth)
3724 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3726 /* Make sure that the ADDIP chunk has a valid length. */
3727 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3728 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3731 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3732 rcvd_serial = ntohl(addip_hdr->serial);
3734 /* Verify the ASCONF-ACK chunk before processing it. */
3735 if (!sctp_verify_asconf(asoc,
3736 (sctp_paramhdr_t *)addip_hdr->params,
3737 (void *)asconf_ack->chunk_end,
3739 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3740 (void *)err_param, commands);
3743 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3744 sent_serial = ntohl(addip_hdr->serial);
3746 sent_serial = asoc->addip_serial - 1;
3749 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3750 * equal to the next serial number to be used but no ASCONF chunk is
3751 * outstanding the endpoint MUST ABORT the association. Note that a
3752 * sequence number is greater than if it is no more than 2^^31-1
3753 * larger than the current sequence number (using serial arithmetic).
3755 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3756 !(asoc->addip_last_asconf)) {
3757 abort = sctp_make_abort(asoc, asconf_ack,
3758 sizeof(sctp_errhdr_t));
3760 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3761 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3764 /* We are going to ABORT, so we might as well stop
3765 * processing the rest of the chunks in the packet.
3767 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3768 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3769 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3770 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3771 SCTP_ERROR(ECONNABORTED));
3772 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3773 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3774 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3775 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3776 return SCTP_DISPOSITION_ABORT;
3779 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3781 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3783 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3785 /* Successfully processed ASCONF_ACK. We can
3786 * release the next asconf if we have one.
3788 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3790 return SCTP_DISPOSITION_CONSUME;
3793 abort = sctp_make_abort(asoc, asconf_ack,
3794 sizeof(sctp_errhdr_t));
3796 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3797 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3800 /* We are going to ABORT, so we might as well stop
3801 * processing the rest of the chunks in the packet.
3803 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3804 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3805 SCTP_ERROR(ECONNABORTED));
3806 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3807 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3808 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3809 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3810 return SCTP_DISPOSITION_ABORT;
3813 return SCTP_DISPOSITION_DISCARD;
3817 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3819 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3820 * its cumulative TSN point to the value carried in the FORWARD TSN
3821 * chunk, and then MUST further advance its cumulative TSN point locally
3823 * After the above processing, the data receiver MUST stop reporting any
3824 * missing TSNs earlier than or equal to the new cumulative TSN point.
3826 * Verification Tag: 8.5 Verification Tag [Normal verification]
3828 * The return value is the disposition of the chunk.
3830 sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3831 const struct sctp_endpoint *ep,
3832 const struct sctp_association *asoc,
3833 const sctp_subtype_t type,
3835 sctp_cmd_seq_t *commands)
3837 struct sctp_chunk *chunk = arg;
3838 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3839 struct sctp_fwdtsn_skip *skip;
3843 if (!sctp_vtag_verify(chunk, asoc)) {
3844 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3846 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3849 /* Make sure that the FORWARD_TSN chunk has valid length. */
3850 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3851 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3854 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3855 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3856 len = ntohs(chunk->chunk_hdr->length);
3857 len -= sizeof(struct sctp_chunkhdr);
3858 skb_pull(chunk->skb, len);
3860 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3861 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3863 /* The TSN is too high--silently discard the chunk and count on it
3864 * getting retransmitted later.
3866 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3867 goto discard_noforce;
3869 /* Silently discard the chunk if stream-id is not valid */
3870 sctp_walk_fwdtsn(skip, chunk) {
3871 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3872 goto discard_noforce;
3875 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3876 if (len > sizeof(struct sctp_fwdtsn_hdr))
3877 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3880 /* Count this as receiving DATA. */
3881 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3882 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3883 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3886 /* FIXME: For now send a SACK, but DATA processing may
3889 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3891 return SCTP_DISPOSITION_CONSUME;
3894 return SCTP_DISPOSITION_DISCARD;
3897 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3899 const struct sctp_endpoint *ep,
3900 const struct sctp_association *asoc,
3901 const sctp_subtype_t type,
3903 sctp_cmd_seq_t *commands)
3905 struct sctp_chunk *chunk = arg;
3906 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3907 struct sctp_fwdtsn_skip *skip;
3911 if (!sctp_vtag_verify(chunk, asoc)) {
3912 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3914 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3917 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3918 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3919 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3922 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3923 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3924 len = ntohs(chunk->chunk_hdr->length);
3925 len -= sizeof(struct sctp_chunkhdr);
3926 skb_pull(chunk->skb, len);
3928 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3929 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3931 /* The TSN is too high--silently discard the chunk and count on it
3932 * getting retransmitted later.
3934 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3937 /* Silently discard the chunk if stream-id is not valid */
3938 sctp_walk_fwdtsn(skip, chunk) {
3939 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3943 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3944 if (len > sizeof(struct sctp_fwdtsn_hdr))
3945 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3948 /* Go a head and force a SACK, since we are shutting down. */
3950 /* Implementor's Guide.
3952 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3953 * respond to each received packet containing one or more DATA chunk(s)
3954 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3956 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3957 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3958 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3959 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3961 return SCTP_DISPOSITION_CONSUME;
3965 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3967 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3968 * Identifier field. If this algorithm was not specified by the
3969 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3970 * during association setup, the AUTH chunk and all chunks after it MUST
3971 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3972 * defined in Section 4.1.
3974 * If an endpoint with no shared key receives a Shared Key Identifier
3975 * other than 0, it MUST silently discard all authenticated chunks. If
3976 * the endpoint has at least one endpoint pair shared key for the peer,
3977 * it MUST use the key specified by the Shared Key Identifier if a
3978 * key has been configured for that Shared Key Identifier. If no
3979 * endpoint pair shared key has been configured for that Shared Key
3980 * Identifier, all authenticated chunks MUST be silently discarded.
3982 * Verification Tag: 8.5 Verification Tag [Normal verification]
3984 * The return value is the disposition of the chunk.
3986 static sctp_ierror_t sctp_sf_authenticate(struct net *net,
3987 const struct sctp_endpoint *ep,
3988 const struct sctp_association *asoc,
3989 const sctp_subtype_t type,
3990 struct sctp_chunk *chunk)
3992 struct sctp_authhdr *auth_hdr;
3993 struct sctp_hmac *hmac;
3994 unsigned int sig_len;
3999 /* Pull in the auth header, so we can do some more verification */
4000 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4001 chunk->subh.auth_hdr = auth_hdr;
4002 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4004 /* Make sure that we support the HMAC algorithm from the auth
4007 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4008 return SCTP_IERROR_AUTH_BAD_HMAC;
4010 /* Make sure that the provided shared key identifier has been
4013 key_id = ntohs(auth_hdr->shkey_id);
4014 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4015 return SCTP_IERROR_AUTH_BAD_KEYID;
4018 /* Make sure that the length of the signature matches what
4021 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4022 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4023 if (sig_len != hmac->hmac_len)
4024 return SCTP_IERROR_PROTO_VIOLATION;
4026 /* Now that we've done validation checks, we can compute and
4027 * verify the hmac. The steps involved are:
4028 * 1. Save the digest from the chunk.
4029 * 2. Zero out the digest in the chunk.
4030 * 3. Compute the new digest
4031 * 4. Compare saved and new digests.
4033 digest = auth_hdr->hmac;
4034 skb_pull(chunk->skb, sig_len);
4036 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4040 memset(digest, 0, sig_len);
4042 sctp_auth_calculate_hmac(asoc, chunk->skb,
4043 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4046 /* Discard the packet if the digests do not match */
4047 if (memcmp(save_digest, digest, sig_len)) {
4049 return SCTP_IERROR_BAD_SIG;
4055 return SCTP_IERROR_NO_ERROR;
4057 return SCTP_IERROR_NOMEM;
4060 sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4061 const struct sctp_endpoint *ep,
4062 const struct sctp_association *asoc,
4063 const sctp_subtype_t type,
4065 sctp_cmd_seq_t *commands)
4067 struct sctp_authhdr *auth_hdr;
4068 struct sctp_chunk *chunk = arg;
4069 struct sctp_chunk *err_chunk;
4070 sctp_ierror_t error;
4072 /* Make sure that the peer has AUTH capable */
4073 if (!asoc->peer.auth_capable)
4074 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4076 if (!sctp_vtag_verify(chunk, asoc)) {
4077 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4079 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4082 /* Make sure that the AUTH chunk has valid length. */
4083 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4084 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4087 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4088 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
4090 case SCTP_IERROR_AUTH_BAD_HMAC:
4091 /* Generate the ERROR chunk and discard the rest
4094 err_chunk = sctp_make_op_error(asoc, chunk,
4095 SCTP_ERROR_UNSUP_HMAC,
4099 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4100 SCTP_CHUNK(err_chunk));
4103 case SCTP_IERROR_AUTH_BAD_KEYID:
4104 case SCTP_IERROR_BAD_SIG:
4105 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4107 case SCTP_IERROR_PROTO_VIOLATION:
4108 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4111 case SCTP_IERROR_NOMEM:
4112 return SCTP_DISPOSITION_NOMEM;
4114 default: /* Prevent gcc warnings */
4118 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4119 struct sctp_ulpevent *ev;
4121 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4122 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4127 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4131 return SCTP_DISPOSITION_CONSUME;
4135 * Process an unknown chunk.
4137 * Section: 3.2. Also, 2.1 in the implementor's guide.
4139 * Chunk Types are encoded such that the highest-order two bits specify
4140 * the action that must be taken if the processing endpoint does not
4141 * recognize the Chunk Type.
4143 * 00 - Stop processing this SCTP packet and discard it, do not process
4144 * any further chunks within it.
4146 * 01 - Stop processing this SCTP packet and discard it, do not process
4147 * any further chunks within it, and report the unrecognized
4148 * chunk in an 'Unrecognized Chunk Type'.
4150 * 10 - Skip this chunk and continue processing.
4152 * 11 - Skip this chunk and continue processing, but report in an ERROR
4153 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4155 * The return value is the disposition of the chunk.
4157 sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4158 const struct sctp_endpoint *ep,
4159 const struct sctp_association *asoc,
4160 const sctp_subtype_t type,
4162 sctp_cmd_seq_t *commands)
4164 struct sctp_chunk *unk_chunk = arg;
4165 struct sctp_chunk *err_chunk;
4166 sctp_chunkhdr_t *hdr;
4168 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4170 if (!sctp_vtag_verify(unk_chunk, asoc))
4171 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4173 /* Make sure that the chunk has a valid length.
4174 * Since we don't know the chunk type, we use a general
4175 * chunkhdr structure to make a comparison.
4177 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4178 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4181 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4182 case SCTP_CID_ACTION_DISCARD:
4183 /* Discard the packet. */
4184 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4185 case SCTP_CID_ACTION_DISCARD_ERR:
4186 /* Generate an ERROR chunk as response. */
4187 hdr = unk_chunk->chunk_hdr;
4188 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4189 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4190 WORD_ROUND(ntohs(hdr->length)),
4193 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4194 SCTP_CHUNK(err_chunk));
4197 /* Discard the packet. */
4198 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4199 return SCTP_DISPOSITION_CONSUME;
4200 case SCTP_CID_ACTION_SKIP:
4201 /* Skip the chunk. */
4202 return SCTP_DISPOSITION_DISCARD;
4203 case SCTP_CID_ACTION_SKIP_ERR:
4204 /* Generate an ERROR chunk as response. */
4205 hdr = unk_chunk->chunk_hdr;
4206 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4207 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4208 WORD_ROUND(ntohs(hdr->length)),
4211 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4212 SCTP_CHUNK(err_chunk));
4214 /* Skip the chunk. */
4215 return SCTP_DISPOSITION_CONSUME;
4220 return SCTP_DISPOSITION_DISCARD;
4224 * Discard the chunk.
4226 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4227 * [Too numerous to mention...]
4228 * Verification Tag: No verification needed.
4230 * (endpoint, asoc, chunk)
4233 * (asoc, reply_msg, msg_up, timers, counters)
4235 * The return value is the disposition of the chunk.
4237 sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4238 const struct sctp_endpoint *ep,
4239 const struct sctp_association *asoc,
4240 const sctp_subtype_t type,
4242 sctp_cmd_seq_t *commands)
4244 struct sctp_chunk *chunk = arg;
4246 /* Make sure that the chunk has a valid length.
4247 * Since we don't know the chunk type, we use a general
4248 * chunkhdr structure to make a comparison.
4250 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4251 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4254 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4256 return SCTP_DISPOSITION_DISCARD;
4260 * Discard the whole packet.
4264 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4265 * silently discard the OOTB packet and take no further action.
4267 * Verification Tag: No verification necessary
4270 * (endpoint, asoc, chunk)
4273 * (asoc, reply_msg, msg_up, timers, counters)
4275 * The return value is the disposition of the chunk.
4277 sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4278 const struct sctp_endpoint *ep,
4279 const struct sctp_association *asoc,
4280 const sctp_subtype_t type,
4282 sctp_cmd_seq_t *commands)
4284 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4285 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4287 return SCTP_DISPOSITION_CONSUME;
4292 * The other end is violating protocol.
4294 * Section: Not specified
4295 * Verification Tag: Not specified
4297 * (endpoint, asoc, chunk)
4300 * (asoc, reply_msg, msg_up, timers, counters)
4302 * We simply tag the chunk as a violation. The state machine will log
4303 * the violation and continue.
4305 sctp_disposition_t sctp_sf_violation(struct net *net,
4306 const struct sctp_endpoint *ep,
4307 const struct sctp_association *asoc,
4308 const sctp_subtype_t type,
4310 sctp_cmd_seq_t *commands)
4312 struct sctp_chunk *chunk = arg;
4314 /* Make sure that the chunk has a valid length. */
4315 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4316 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4319 return SCTP_DISPOSITION_VIOLATION;
4323 * Common function to handle a protocol violation.
4325 static sctp_disposition_t sctp_sf_abort_violation(
4327 const struct sctp_endpoint *ep,
4328 const struct sctp_association *asoc,
4330 sctp_cmd_seq_t *commands,
4331 const __u8 *payload,
4332 const size_t paylen)
4334 struct sctp_packet *packet = NULL;
4335 struct sctp_chunk *chunk = arg;
4336 struct sctp_chunk *abort = NULL;
4338 /* SCTP-AUTH, Section 6.3:
4339 * It should be noted that if the receiver wants to tear
4340 * down an association in an authenticated way only, the
4341 * handling of malformed packets should not result in
4342 * tearing down the association.
4344 * This means that if we only want to abort associations
4345 * in an authenticated way (i.e AUTH+ABORT), then we
4346 * can't destroy this association just because the packet
4349 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4352 /* Make the abort chunk. */
4353 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4358 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4359 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4360 !asoc->peer.i.init_tag) {
4361 sctp_initack_chunk_t *initack;
4363 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4364 if (!sctp_chunk_length_valid(chunk,
4365 sizeof(sctp_initack_chunk_t)))
4366 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4368 unsigned int inittag;
4370 inittag = ntohl(initack->init_hdr.init_tag);
4371 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4376 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4377 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4379 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4380 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4381 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4382 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4383 SCTP_ERROR(ECONNREFUSED));
4384 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4385 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4387 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4388 SCTP_ERROR(ECONNABORTED));
4389 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4390 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4391 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4394 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4399 if (sctp_test_T_bit(abort))
4400 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4402 abort->skb->sk = ep->base.sk;
4404 sctp_packet_append_chunk(packet, abort);
4406 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4407 SCTP_PACKET(packet));
4409 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4412 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4415 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4416 return SCTP_DISPOSITION_ABORT;
4419 sctp_chunk_free(abort);
4421 return SCTP_DISPOSITION_NOMEM;
4425 * Handle a protocol violation when the chunk length is invalid.
4426 * "Invalid" length is identified as smaller than the minimal length a
4427 * given chunk can be. For example, a SACK chunk has invalid length
4428 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4430 * We inform the other end by sending an ABORT with a Protocol Violation
4433 * Section: Not specified
4434 * Verification Tag: Nothing to do
4436 * (endpoint, asoc, chunk)
4439 * (reply_msg, msg_up, counters)
4441 * Generate an ABORT chunk and terminate the association.
4443 static sctp_disposition_t sctp_sf_violation_chunklen(
4445 const struct sctp_endpoint *ep,
4446 const struct sctp_association *asoc,
4447 const sctp_subtype_t type,
4449 sctp_cmd_seq_t *commands)
4451 static const char err_str[] = "The following chunk had invalid length:";
4453 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4458 * Handle a protocol violation when the parameter length is invalid.
4459 * If the length is smaller than the minimum length of a given parameter,
4460 * or accumulated length in multi parameters exceeds the end of the chunk,
4461 * the length is considered as invalid.
4463 static sctp_disposition_t sctp_sf_violation_paramlen(
4465 const struct sctp_endpoint *ep,
4466 const struct sctp_association *asoc,
4467 const sctp_subtype_t type,
4468 void *arg, void *ext,
4469 sctp_cmd_seq_t *commands)
4471 struct sctp_chunk *chunk = arg;
4472 struct sctp_paramhdr *param = ext;
4473 struct sctp_chunk *abort = NULL;
4475 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4478 /* Make the abort chunk. */
4479 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4483 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4484 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4486 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4487 SCTP_ERROR(ECONNABORTED));
4488 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4489 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4490 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4491 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4494 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4495 return SCTP_DISPOSITION_ABORT;
4497 return SCTP_DISPOSITION_NOMEM;
4500 /* Handle a protocol violation when the peer trying to advance the
4501 * cumulative tsn ack to a point beyond the max tsn currently sent.
4503 * We inform the other end by sending an ABORT with a Protocol Violation
4506 static sctp_disposition_t sctp_sf_violation_ctsn(
4508 const struct sctp_endpoint *ep,
4509 const struct sctp_association *asoc,
4510 const sctp_subtype_t type,
4512 sctp_cmd_seq_t *commands)
4514 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4516 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4520 /* Handle protocol violation of an invalid chunk bundling. For example,
4521 * when we have an association and we receive bundled INIT-ACK, or
4522 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4523 * statement from the specs. Additionally, there might be an attacker
4524 * on the path and we may not want to continue this communication.
4526 static sctp_disposition_t sctp_sf_violation_chunk(
4528 const struct sctp_endpoint *ep,
4529 const struct sctp_association *asoc,
4530 const sctp_subtype_t type,
4532 sctp_cmd_seq_t *commands)
4534 static const char err_str[] = "The following chunk violates protocol:";
4537 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
4539 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4542 /***************************************************************************
4543 * These are the state functions for handling primitive (Section 10) events.
4544 ***************************************************************************/
4546 * sctp_sf_do_prm_asoc
4548 * Section: 10.1 ULP-to-SCTP
4551 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4552 * outbound stream count)
4553 * -> association id [,destination transport addr list] [,outbound stream
4556 * This primitive allows the upper layer to initiate an association to a
4557 * specific peer endpoint.
4559 * The peer endpoint shall be specified by one of the transport addresses
4560 * which defines the endpoint (see Section 1.4). If the local SCTP
4561 * instance has not been initialized, the ASSOCIATE is considered an
4563 * [This is not relevant for the kernel implementation since we do all
4564 * initialization at boot time. It we hadn't initialized we wouldn't
4565 * get anywhere near this code.]
4567 * An association id, which is a local handle to the SCTP association,
4568 * will be returned on successful establishment of the association. If
4569 * SCTP is not able to open an SCTP association with the peer endpoint,
4570 * an error is returned.
4571 * [In the kernel implementation, the struct sctp_association needs to
4572 * be created BEFORE causing this primitive to run.]
4574 * Other association parameters may be returned, including the
4575 * complete destination transport addresses of the peer as well as the
4576 * outbound stream count of the local endpoint. One of the transport
4577 * address from the returned destination addresses will be selected by
4578 * the local endpoint as default primary path for sending SCTP packets
4579 * to this peer. The returned "destination transport addr list" can
4580 * be used by the ULP to change the default primary path or to force
4581 * sending a packet to a specific transport address. [All of this
4582 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4585 * Mandatory attributes:
4587 * o local SCTP instance name - obtained from the INITIALIZE operation.
4588 * [This is the argument asoc.]
4589 * o destination transport addr - specified as one of the transport
4590 * addresses of the peer endpoint with which the association is to be
4592 * [This is asoc->peer.active_path.]
4593 * o outbound stream count - the number of outbound streams the ULP
4594 * would like to open towards this peer endpoint.
4595 * [BUG: This is not currently implemented.]
4596 * Optional attributes:
4600 * The return value is a disposition.
4602 sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4603 const struct sctp_endpoint *ep,
4604 const struct sctp_association *asoc,
4605 const sctp_subtype_t type,
4607 sctp_cmd_seq_t *commands)
4609 struct sctp_chunk *repl;
4610 struct sctp_association *my_asoc;
4612 /* The comment below says that we enter COOKIE-WAIT AFTER
4613 * sending the INIT, but that doesn't actually work in our
4616 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4617 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4619 /* RFC 2960 5.1 Normal Establishment of an Association
4621 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4622 * must provide its Verification Tag (Tag_A) in the Initiate
4623 * Tag field. Tag_A SHOULD be a random number in the range of
4624 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4627 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4631 /* Choose transport for INIT. */
4632 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4635 /* Cast away the const modifier, as we want to just
4636 * rerun it through as a sideffect.
4638 my_asoc = (struct sctp_association *)asoc;
4639 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4641 /* After sending the INIT, "A" starts the T1-init timer and
4642 * enters the COOKIE-WAIT state.
4644 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4645 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4646 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4647 return SCTP_DISPOSITION_CONSUME;
4650 return SCTP_DISPOSITION_NOMEM;
4654 * Process the SEND primitive.
4656 * Section: 10.1 ULP-to-SCTP
4659 * Format: SEND(association id, buffer address, byte count [,context]
4660 * [,stream id] [,life time] [,destination transport address]
4661 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4664 * This is the main method to send user data via SCTP.
4666 * Mandatory attributes:
4668 * o association id - local handle to the SCTP association
4670 * o buffer address - the location where the user message to be
4671 * transmitted is stored;
4673 * o byte count - The size of the user data in number of bytes;
4675 * Optional attributes:
4677 * o context - an optional 32 bit integer that will be carried in the
4678 * sending failure notification to the ULP if the transportation of
4679 * this User Message fails.
4681 * o stream id - to indicate which stream to send the data on. If not
4682 * specified, stream 0 will be used.
4684 * o life time - specifies the life time of the user data. The user data
4685 * will not be sent by SCTP after the life time expires. This
4686 * parameter can be used to avoid efforts to transmit stale
4687 * user messages. SCTP notifies the ULP if the data cannot be
4688 * initiated to transport (i.e. sent to the destination via SCTP's
4689 * send primitive) within the life time variable. However, the
4690 * user data will be transmitted if SCTP has attempted to transmit a
4691 * chunk before the life time expired.
4693 * o destination transport address - specified as one of the destination
4694 * transport addresses of the peer endpoint to which this packet
4695 * should be sent. Whenever possible, SCTP should use this destination
4696 * transport address for sending the packets, instead of the current
4699 * o unorder flag - this flag, if present, indicates that the user
4700 * would like the data delivered in an unordered fashion to the peer
4701 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4704 * o no-bundle flag - instructs SCTP not to bundle this user data with
4705 * other outbound DATA chunks. SCTP MAY still bundle even when
4706 * this flag is present, when faced with network congestion.
4708 * o payload protocol-id - A 32 bit unsigned integer that is to be
4709 * passed to the peer indicating the type of payload protocol data
4710 * being transmitted. This value is passed as opaque data by SCTP.
4712 * The return value is the disposition.
4714 sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4715 const struct sctp_endpoint *ep,
4716 const struct sctp_association *asoc,
4717 const sctp_subtype_t type,
4719 sctp_cmd_seq_t *commands)
4721 struct sctp_datamsg *msg = arg;
4723 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4724 return SCTP_DISPOSITION_CONSUME;
4728 * Process the SHUTDOWN primitive.
4733 * Format: SHUTDOWN(association id)
4736 * Gracefully closes an association. Any locally queued user data
4737 * will be delivered to the peer. The association will be terminated only
4738 * after the peer acknowledges all the SCTP packets sent. A success code
4739 * will be returned on successful termination of the association. If
4740 * attempting to terminate the association results in a failure, an error
4741 * code shall be returned.
4743 * Mandatory attributes:
4745 * o association id - local handle to the SCTP association
4747 * Optional attributes:
4751 * The return value is the disposition.
4753 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4755 const struct sctp_endpoint *ep,
4756 const struct sctp_association *asoc,
4757 const sctp_subtype_t type,
4759 sctp_cmd_seq_t *commands)
4763 /* From 9.2 Shutdown of an Association
4764 * Upon receipt of the SHUTDOWN primitive from its upper
4765 * layer, the endpoint enters SHUTDOWN-PENDING state and
4766 * remains there until all outstanding data has been
4767 * acknowledged by its peer. The endpoint accepts no new data
4768 * from its upper layer, but retransmits data to the far end
4769 * if necessary to fill gaps.
4771 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4772 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4774 disposition = SCTP_DISPOSITION_CONSUME;
4775 if (sctp_outq_is_empty(&asoc->outqueue)) {
4776 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
4783 * Process the ABORT primitive.
4788 * Format: Abort(association id [, cause code])
4791 * Ungracefully closes an association. Any locally queued user data
4792 * will be discarded and an ABORT chunk is sent to the peer. A success code
4793 * will be returned on successful abortion of the association. If
4794 * attempting to abort the association results in a failure, an error
4795 * code shall be returned.
4797 * Mandatory attributes:
4799 * o association id - local handle to the SCTP association
4801 * Optional attributes:
4803 * o cause code - reason of the abort to be passed to the peer
4807 * The return value is the disposition.
4809 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4811 const struct sctp_endpoint *ep,
4812 const struct sctp_association *asoc,
4813 const sctp_subtype_t type,
4815 sctp_cmd_seq_t *commands)
4817 /* From 9.1 Abort of an Association
4818 * Upon receipt of the ABORT primitive from its upper
4819 * layer, the endpoint enters CLOSED state and
4820 * discard all outstanding data has been
4821 * acknowledged by its peer. The endpoint accepts no new data
4822 * from its upper layer, but retransmits data to the far end
4823 * if necessary to fill gaps.
4825 struct sctp_chunk *abort = arg;
4826 sctp_disposition_t retval;
4828 retval = SCTP_DISPOSITION_CONSUME;
4830 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4832 /* Even if we can't send the ABORT due to low memory delete the
4833 * TCB. This is a departure from our typical NOMEM handling.
4836 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4837 SCTP_ERROR(ECONNABORTED));
4838 /* Delete the established association. */
4839 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4840 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4842 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4843 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4848 /* We tried an illegal operation on an association which is closed. */
4849 sctp_disposition_t sctp_sf_error_closed(struct net *net,
4850 const struct sctp_endpoint *ep,
4851 const struct sctp_association *asoc,
4852 const sctp_subtype_t type,
4854 sctp_cmd_seq_t *commands)
4856 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4857 return SCTP_DISPOSITION_CONSUME;
4860 /* We tried an illegal operation on an association which is shutting
4863 sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4864 const struct sctp_endpoint *ep,
4865 const struct sctp_association *asoc,
4866 const sctp_subtype_t type,
4868 sctp_cmd_seq_t *commands)
4870 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4871 SCTP_ERROR(-ESHUTDOWN));
4872 return SCTP_DISPOSITION_CONSUME;
4876 * sctp_cookie_wait_prm_shutdown
4878 * Section: 4 Note: 2
4883 * The RFC does not explicitly address this issue, but is the route through the
4884 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4889 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4891 const struct sctp_endpoint *ep,
4892 const struct sctp_association *asoc,
4893 const sctp_subtype_t type,
4895 sctp_cmd_seq_t *commands)
4897 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4898 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4900 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4901 SCTP_STATE(SCTP_STATE_CLOSED));
4903 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
4905 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4907 return SCTP_DISPOSITION_DELETE_TCB;
4911 * sctp_cookie_echoed_prm_shutdown
4913 * Section: 4 Note: 2
4918 * The RFC does not explcitly address this issue, but is the route through the
4919 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4924 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4926 const struct sctp_endpoint *ep,
4927 const struct sctp_association *asoc,
4928 const sctp_subtype_t type,
4929 void *arg, sctp_cmd_seq_t *commands)
4931 /* There is a single T1 timer, so we should be able to use
4932 * common function with the COOKIE-WAIT state.
4934 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
4938 * sctp_sf_cookie_wait_prm_abort
4940 * Section: 4 Note: 2
4945 * The RFC does not explicitly address this issue, but is the route through the
4946 * state table when someone issues an abort while in COOKIE_WAIT state.
4951 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4953 const struct sctp_endpoint *ep,
4954 const struct sctp_association *asoc,
4955 const sctp_subtype_t type,
4957 sctp_cmd_seq_t *commands)
4959 struct sctp_chunk *abort = arg;
4960 sctp_disposition_t retval;
4962 /* Stop T1-init timer */
4963 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4964 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4965 retval = SCTP_DISPOSITION_CONSUME;
4967 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4969 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4970 SCTP_STATE(SCTP_STATE_CLOSED));
4972 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4974 /* Even if we can't send the ABORT due to low memory delete the
4975 * TCB. This is a departure from our typical NOMEM handling.
4978 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4979 SCTP_ERROR(ECONNREFUSED));
4980 /* Delete the established association. */
4981 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4982 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4988 * sctp_sf_cookie_echoed_prm_abort
4990 * Section: 4 Note: 3
4995 * The RFC does not explcitly address this issue, but is the route through the
4996 * state table when someone issues an abort while in COOKIE_ECHOED state.
5001 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
5003 const struct sctp_endpoint *ep,
5004 const struct sctp_association *asoc,
5005 const sctp_subtype_t type,
5007 sctp_cmd_seq_t *commands)
5009 /* There is a single T1 timer, so we should be able to use
5010 * common function with the COOKIE-WAIT state.
5012 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5016 * sctp_sf_shutdown_pending_prm_abort
5021 * The RFC does not explicitly address this issue, but is the route through the
5022 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5027 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
5029 const struct sctp_endpoint *ep,
5030 const struct sctp_association *asoc,
5031 const sctp_subtype_t type,
5033 sctp_cmd_seq_t *commands)
5035 /* Stop the T5-shutdown guard timer. */
5036 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5037 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5039 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5043 * sctp_sf_shutdown_sent_prm_abort
5048 * The RFC does not explicitly address this issue, but is the route through the
5049 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5054 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
5056 const struct sctp_endpoint *ep,
5057 const struct sctp_association *asoc,
5058 const sctp_subtype_t type,
5060 sctp_cmd_seq_t *commands)
5062 /* Stop the T2-shutdown timer. */
5063 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5064 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5066 /* Stop the T5-shutdown guard timer. */
5067 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5068 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5070 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5074 * sctp_sf_cookie_echoed_prm_abort
5079 * The RFC does not explcitly address this issue, but is the route through the
5080 * state table when someone issues an abort while in COOKIE_ECHOED state.
5085 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
5087 const struct sctp_endpoint *ep,
5088 const struct sctp_association *asoc,
5089 const sctp_subtype_t type,
5091 sctp_cmd_seq_t *commands)
5093 /* The same T2 timer, so we should be able to use
5094 * common function with the SHUTDOWN-SENT state.
5096 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5100 * Process the REQUESTHEARTBEAT primitive
5103 * J) Request Heartbeat
5105 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5109 * Instructs the local endpoint to perform a HeartBeat on the specified
5110 * destination transport address of the given association. The returned
5111 * result should indicate whether the transmission of the HEARTBEAT
5112 * chunk to the destination address is successful.
5114 * Mandatory attributes:
5116 * o association id - local handle to the SCTP association
5118 * o destination transport address - the transport address of the
5119 * association on which a heartbeat should be issued.
5121 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5123 const struct sctp_endpoint *ep,
5124 const struct sctp_association *asoc,
5125 const sctp_subtype_t type,
5127 sctp_cmd_seq_t *commands)
5129 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5130 (struct sctp_transport *)arg, commands))
5131 return SCTP_DISPOSITION_NOMEM;
5134 * RFC 2960 (bis), section 8.3
5136 * D) Request an on-demand HEARTBEAT on a specific destination
5137 * transport address of a given association.
5139 * The endpoint should increment the respective error counter of
5140 * the destination transport address each time a HEARTBEAT is sent
5141 * to that address and not acknowledged within one RTO.
5144 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5145 SCTP_TRANSPORT(arg));
5146 return SCTP_DISPOSITION_CONSUME;
5150 * ADDIP Section 4.1 ASCONF Chunk Procedures
5151 * When an endpoint has an ASCONF signaled change to be sent to the
5152 * remote endpoint it should do A1 to A9
5154 sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5155 const struct sctp_endpoint *ep,
5156 const struct sctp_association *asoc,
5157 const sctp_subtype_t type,
5159 sctp_cmd_seq_t *commands)
5161 struct sctp_chunk *chunk = arg;
5163 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5164 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5165 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5166 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5167 return SCTP_DISPOSITION_CONSUME;
5171 * Ignore the primitive event
5173 * The return value is the disposition of the primitive.
5175 sctp_disposition_t sctp_sf_ignore_primitive(
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 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5186 return SCTP_DISPOSITION_DISCARD;
5189 /***************************************************************************
5190 * These are the state functions for the OTHER events.
5191 ***************************************************************************/
5194 * When the SCTP stack has no more user data to send or retransmit, this
5195 * notification is given to the user. Also, at the time when a user app
5196 * subscribes to this event, if there is no data to be sent or
5197 * retransmit, the stack will immediately send up this notification.
5199 sctp_disposition_t sctp_sf_do_no_pending_tsn(
5201 const struct sctp_endpoint *ep,
5202 const struct sctp_association *asoc,
5203 const sctp_subtype_t type,
5205 sctp_cmd_seq_t *commands)
5207 struct sctp_ulpevent *event;
5209 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5211 return SCTP_DISPOSITION_NOMEM;
5213 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5215 return SCTP_DISPOSITION_CONSUME;
5219 * Start the shutdown negotiation.
5222 * Once all its outstanding data has been acknowledged, the endpoint
5223 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5224 * TSN Ack field the last sequential TSN it has received from the peer.
5225 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5226 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5227 * with the updated last sequential TSN received from its peer.
5229 * The return value is the disposition.
5231 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5233 const struct sctp_endpoint *ep,
5234 const struct sctp_association *asoc,
5235 const sctp_subtype_t type,
5237 sctp_cmd_seq_t *commands)
5239 struct sctp_chunk *reply;
5241 /* Once all its outstanding data has been acknowledged, the
5242 * endpoint shall send a SHUTDOWN chunk to its peer including
5243 * in the Cumulative TSN Ack field the last sequential TSN it
5244 * has received from the peer.
5246 reply = sctp_make_shutdown(asoc, NULL);
5250 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5251 * T2-shutdown timer.
5253 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5255 /* It shall then start the T2-shutdown timer */
5256 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5257 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5259 /* RFC 4960 Section 9.2
5260 * The sender of the SHUTDOWN MAY also start an overall guard timer
5261 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5263 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5264 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5266 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5267 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5268 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5270 /* and enter the SHUTDOWN-SENT state. */
5271 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5272 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5274 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5276 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5279 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5281 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5283 return SCTP_DISPOSITION_CONSUME;
5286 return SCTP_DISPOSITION_NOMEM;
5290 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5294 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5295 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5296 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5297 * endpoint must re-send the SHUTDOWN ACK.
5299 * The return value is the disposition.
5301 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5303 const struct sctp_endpoint *ep,
5304 const struct sctp_association *asoc,
5305 const sctp_subtype_t type,
5307 sctp_cmd_seq_t *commands)
5309 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5310 struct sctp_chunk *reply;
5312 /* There are 2 ways of getting here:
5313 * 1) called in response to a SHUTDOWN chunk
5314 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5316 * For the case (2), the arg parameter is set to NULL. We need
5317 * to check that we have a chunk before accessing it's fields.
5320 if (!sctp_vtag_verify(chunk, asoc))
5321 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
5323 /* Make sure that the SHUTDOWN chunk has a valid length. */
5324 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5325 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
5329 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5330 * shall send a SHUTDOWN ACK ...
5332 reply = sctp_make_shutdown_ack(asoc, chunk);
5336 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5337 * the T2-shutdown timer.
5339 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5341 /* and start/restart a T2-shutdown timer of its own, */
5342 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5343 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5345 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5347 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5349 /* Enter the SHUTDOWN-ACK-SENT state. */
5350 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5351 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5353 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5355 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5358 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5360 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5362 return SCTP_DISPOSITION_CONSUME;
5365 return SCTP_DISPOSITION_NOMEM;
5369 * Ignore the event defined as other
5371 * The return value is the disposition of the event.
5373 sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5374 const struct sctp_endpoint *ep,
5375 const struct sctp_association *asoc,
5376 const sctp_subtype_t type,
5378 sctp_cmd_seq_t *commands)
5380 pr_debug("%s: the event other type:%d is ignored\n",
5381 __func__, type.other);
5383 return SCTP_DISPOSITION_DISCARD;
5386 /************************************************************
5387 * These are the state functions for handling timeout events.
5388 ************************************************************/
5393 * Section: 6.3.3 Handle T3-rtx Expiration
5395 * Whenever the retransmission timer T3-rtx expires for a destination
5396 * address, do the following:
5399 * The return value is the disposition of the chunk.
5401 sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5402 const struct sctp_endpoint *ep,
5403 const struct sctp_association *asoc,
5404 const sctp_subtype_t type,
5406 sctp_cmd_seq_t *commands)
5408 struct sctp_transport *transport = arg;
5410 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5412 if (asoc->overall_error_count >= asoc->max_retrans) {
5413 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5415 * We are here likely because the receiver had its rwnd
5416 * closed for a while and we have not been able to
5417 * transmit the locally queued data within the maximum
5418 * retransmission attempts limit. Start the T5
5419 * shutdown guard timer to give the receiver one last
5420 * chance and some additional time to recover before
5423 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5424 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5426 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5427 SCTP_ERROR(ETIMEDOUT));
5428 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5429 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5430 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5431 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5432 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5433 return SCTP_DISPOSITION_DELETE_TCB;
5437 /* E1) For the destination address for which the timer
5438 * expires, adjust its ssthresh with rules defined in Section
5439 * 7.2.3 and set the cwnd <- MTU.
5442 /* E2) For the destination address for which the timer
5443 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5444 * maximum value discussed in rule C7 above (RTO.max) may be
5445 * used to provide an upper bound to this doubling operation.
5448 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5449 * outstanding DATA chunks for the address for which the
5450 * T3-rtx has expired will fit into a single packet, subject
5451 * to the MTU constraint for the path corresponding to the
5452 * destination transport address to which the retransmission
5453 * is being sent (this may be different from the address for
5454 * which the timer expires [see Section 6.4]). Call this
5455 * value K. Bundle and retransmit those K DATA chunks in a
5456 * single packet to the destination endpoint.
5458 * Note: Any DATA chunks that were sent to the address for
5459 * which the T3-rtx timer expired but did not fit in one MTU
5460 * (rule E3 above), should be marked for retransmission and
5461 * sent as soon as cwnd allows (normally when a SACK arrives).
5464 /* Do some failure management (Section 8.2). */
5465 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5467 /* NB: Rules E4 and F1 are implicit in R1. */
5468 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5470 return SCTP_DISPOSITION_CONSUME;
5474 * Generate delayed SACK on timeout
5476 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5478 * The guidelines on delayed acknowledgement algorithm specified in
5479 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5480 * acknowledgement SHOULD be generated for at least every second packet
5481 * (not every second DATA chunk) received, and SHOULD be generated
5482 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5483 * some situations it may be beneficial for an SCTP transmitter to be
5484 * more conservative than the algorithms detailed in this document
5485 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5486 * the following algorithms allow.
5488 sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5489 const struct sctp_endpoint *ep,
5490 const struct sctp_association *asoc,
5491 const sctp_subtype_t type,
5493 sctp_cmd_seq_t *commands)
5495 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5496 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5497 return SCTP_DISPOSITION_CONSUME;
5501 * sctp_sf_t1_init_timer_expire
5503 * Section: 4 Note: 2
5508 * RFC 2960 Section 4 Notes
5509 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5510 * and re-start the T1-init timer without changing state. This MUST
5511 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5512 * endpoint MUST abort the initialization process and report the
5513 * error to SCTP user.
5519 sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5520 const struct sctp_endpoint *ep,
5521 const struct sctp_association *asoc,
5522 const sctp_subtype_t type,
5524 sctp_cmd_seq_t *commands)
5526 struct sctp_chunk *repl = NULL;
5527 struct sctp_bind_addr *bp;
5528 int attempts = asoc->init_err_counter + 1;
5530 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5532 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5534 if (attempts <= asoc->max_init_attempts) {
5535 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5536 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5538 return SCTP_DISPOSITION_NOMEM;
5540 /* Choose transport for INIT. */
5541 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5544 /* Issue a sideeffect to do the needed accounting. */
5545 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5546 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5548 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5550 pr_debug("%s: giving up on INIT, attempts:%d "
5551 "max_init_attempts:%d\n", __func__, attempts,
5552 asoc->max_init_attempts);
5554 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5555 SCTP_ERROR(ETIMEDOUT));
5556 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5557 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5558 return SCTP_DISPOSITION_DELETE_TCB;
5561 return SCTP_DISPOSITION_CONSUME;
5565 * sctp_sf_t1_cookie_timer_expire
5567 * Section: 4 Note: 2
5572 * RFC 2960 Section 4 Notes
5573 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5574 * COOKIE ECHO and re-start the T1-cookie timer without changing
5575 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5576 * After that, the endpoint MUST abort the initialization process and
5577 * report the error to SCTP user.
5583 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5584 const struct sctp_endpoint *ep,
5585 const struct sctp_association *asoc,
5586 const sctp_subtype_t type,
5588 sctp_cmd_seq_t *commands)
5590 struct sctp_chunk *repl = NULL;
5591 int attempts = asoc->init_err_counter + 1;
5593 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5595 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5597 if (attempts <= asoc->max_init_attempts) {
5598 repl = sctp_make_cookie_echo(asoc, NULL);
5600 return SCTP_DISPOSITION_NOMEM;
5602 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5604 /* Issue a sideeffect to do the needed accounting. */
5605 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5606 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5608 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5610 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5611 SCTP_ERROR(ETIMEDOUT));
5612 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5613 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5614 return SCTP_DISPOSITION_DELETE_TCB;
5617 return SCTP_DISPOSITION_CONSUME;
5620 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5621 * with the updated last sequential TSN received from its peer.
5623 * An endpoint should limit the number of retransmissions of the
5624 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5625 * If this threshold is exceeded the endpoint should destroy the TCB and
5626 * MUST report the peer endpoint unreachable to the upper layer (and
5627 * thus the association enters the CLOSED state). The reception of any
5628 * packet from its peer (i.e. as the peer sends all of its queued DATA
5629 * chunks) should clear the endpoint's retransmission count and restart
5630 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5631 * all of its queued DATA chunks that have not yet been sent.
5633 sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5634 const struct sctp_endpoint *ep,
5635 const struct sctp_association *asoc,
5636 const sctp_subtype_t type,
5638 sctp_cmd_seq_t *commands)
5640 struct sctp_chunk *reply = NULL;
5642 pr_debug("%s: timer T2 expired\n", __func__);
5644 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5646 ((struct sctp_association *)asoc)->shutdown_retries++;
5648 if (asoc->overall_error_count >= asoc->max_retrans) {
5649 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5650 SCTP_ERROR(ETIMEDOUT));
5651 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5652 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5653 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5654 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5655 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5656 return SCTP_DISPOSITION_DELETE_TCB;
5659 switch (asoc->state) {
5660 case SCTP_STATE_SHUTDOWN_SENT:
5661 reply = sctp_make_shutdown(asoc, NULL);
5664 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5665 reply = sctp_make_shutdown_ack(asoc, NULL);
5676 /* Do some failure management (Section 8.2).
5677 * If we remove the transport an SHUTDOWN was last sent to, don't
5678 * do failure management.
5680 if (asoc->shutdown_last_sent_to)
5681 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5682 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5684 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5685 * the T2-shutdown timer.
5687 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5689 /* Restart the T2-shutdown timer. */
5690 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5691 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5693 return SCTP_DISPOSITION_CONSUME;
5696 return SCTP_DISPOSITION_NOMEM;
5700 * ADDIP Section 4.1 ASCONF CHunk Procedures
5701 * If the T4 RTO timer expires the endpoint should do B1 to B5
5703 sctp_disposition_t sctp_sf_t4_timer_expire(
5705 const struct sctp_endpoint *ep,
5706 const struct sctp_association *asoc,
5707 const sctp_subtype_t type,
5709 sctp_cmd_seq_t *commands)
5711 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5712 struct sctp_transport *transport = chunk->transport;
5714 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
5716 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5717 * detection on the appropriate destination address as defined in
5718 * RFC2960 [5] section 8.1 and 8.2.
5721 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5722 SCTP_TRANSPORT(transport));
5724 /* Reconfig T4 timer and transport. */
5725 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5727 /* ADDIP 4.1 B2) Increment the association error counters and perform
5728 * endpoint failure detection on the association as defined in
5729 * RFC2960 [5] section 8.1 and 8.2.
5730 * association error counter is incremented in SCTP_CMD_STRIKE.
5732 if (asoc->overall_error_count >= asoc->max_retrans) {
5733 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5734 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5735 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5736 SCTP_ERROR(ETIMEDOUT));
5737 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5738 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5739 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5740 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5741 return SCTP_DISPOSITION_ABORT;
5744 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5745 * the ASCONF chunk was sent by doubling the RTO timer value.
5746 * This is done in SCTP_CMD_STRIKE.
5749 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5750 * choose an alternate destination address (please refer to RFC2960
5751 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5752 * chunk, it MUST be the same (including its serial number) as the last
5755 sctp_chunk_hold(asoc->addip_last_asconf);
5756 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5757 SCTP_CHUNK(asoc->addip_last_asconf));
5759 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5760 * destination is selected, then the RTO used will be that of the new
5761 * destination address.
5763 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5764 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5766 return SCTP_DISPOSITION_CONSUME;
5769 /* sctpimpguide-05 Section 2.12.2
5770 * The sender of the SHUTDOWN MAY also start an overall guard timer
5771 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5772 * At the expiration of this timer the sender SHOULD abort the association
5773 * by sending an ABORT chunk.
5775 sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5776 const struct sctp_endpoint *ep,
5777 const struct sctp_association *asoc,
5778 const sctp_subtype_t type,
5780 sctp_cmd_seq_t *commands)
5782 struct sctp_chunk *reply = NULL;
5784 pr_debug("%s: timer T5 expired\n", __func__);
5786 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5788 reply = sctp_make_abort(asoc, NULL, 0);
5792 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5793 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5794 SCTP_ERROR(ETIMEDOUT));
5795 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5796 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5798 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5799 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5801 return SCTP_DISPOSITION_DELETE_TCB;
5803 return SCTP_DISPOSITION_NOMEM;
5806 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5807 * the association is automatically closed by starting the shutdown process.
5808 * The work that needs to be done is same as when SHUTDOWN is initiated by
5809 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5811 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5813 const struct sctp_endpoint *ep,
5814 const struct sctp_association *asoc,
5815 const sctp_subtype_t type,
5817 sctp_cmd_seq_t *commands)
5821 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
5823 /* From 9.2 Shutdown of an Association
5824 * Upon receipt of the SHUTDOWN primitive from its upper
5825 * layer, the endpoint enters SHUTDOWN-PENDING state and
5826 * remains there until all outstanding data has been
5827 * acknowledged by its peer. The endpoint accepts no new data
5828 * from its upper layer, but retransmits data to the far end
5829 * if necessary to fill gaps.
5831 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5832 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5834 disposition = SCTP_DISPOSITION_CONSUME;
5835 if (sctp_outq_is_empty(&asoc->outqueue)) {
5836 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
5842 /*****************************************************************************
5843 * These are sa state functions which could apply to all types of events.
5844 ****************************************************************************/
5847 * This table entry is not implemented.
5850 * (endpoint, asoc, chunk)
5852 * The return value is the disposition of the chunk.
5854 sctp_disposition_t sctp_sf_not_impl(struct net *net,
5855 const struct sctp_endpoint *ep,
5856 const struct sctp_association *asoc,
5857 const sctp_subtype_t type,
5859 sctp_cmd_seq_t *commands)
5861 return SCTP_DISPOSITION_NOT_IMPL;
5865 * This table entry represents a bug.
5868 * (endpoint, asoc, chunk)
5870 * The return value is the disposition of the chunk.
5872 sctp_disposition_t sctp_sf_bug(struct net *net,
5873 const struct sctp_endpoint *ep,
5874 const struct sctp_association *asoc,
5875 const sctp_subtype_t type,
5877 sctp_cmd_seq_t *commands)
5879 return SCTP_DISPOSITION_BUG;
5883 * This table entry represents the firing of a timer in the wrong state.
5884 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5885 * when the association is in the wrong state. This event should
5886 * be ignored, so as to prevent any rearming of the timer.
5889 * (endpoint, asoc, chunk)
5891 * The return value is the disposition of the chunk.
5893 sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5894 const struct sctp_endpoint *ep,
5895 const struct sctp_association *asoc,
5896 const sctp_subtype_t type,
5898 sctp_cmd_seq_t *commands)
5900 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
5902 return SCTP_DISPOSITION_CONSUME;
5905 /********************************************************************
5906 * 2nd Level Abstractions
5907 ********************************************************************/
5909 /* Pull the SACK chunk based on the SACK header. */
5910 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5912 struct sctp_sackhdr *sack;
5917 /* Protect ourselves from reading too far into
5918 * the skb from a bogus sender.
5920 sack = (struct sctp_sackhdr *) chunk->skb->data;
5922 num_blocks = ntohs(sack->num_gap_ack_blocks);
5923 num_dup_tsns = ntohs(sack->num_dup_tsns);
5924 len = sizeof(struct sctp_sackhdr);
5925 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5926 if (len > chunk->skb->len)
5929 skb_pull(chunk->skb, len);
5934 /* Create an ABORT packet to be sent as a response, with the specified
5937 static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
5938 const struct sctp_endpoint *ep,
5939 const struct sctp_association *asoc,
5940 struct sctp_chunk *chunk,
5941 const void *payload,
5944 struct sctp_packet *packet;
5945 struct sctp_chunk *abort;
5947 packet = sctp_ootb_pkt_new(net, asoc, chunk);
5951 * The T bit will be set if the asoc is NULL.
5953 abort = sctp_make_abort(asoc, chunk, paylen);
5955 sctp_ootb_pkt_free(packet);
5959 /* Reflect vtag if T-Bit is set */
5960 if (sctp_test_T_bit(abort))
5961 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5963 /* Add specified error causes, i.e., payload, to the
5966 sctp_addto_chunk(abort, paylen, payload);
5968 /* Set the skb to the belonging sock for accounting. */
5969 abort->skb->sk = ep->base.sk;
5971 sctp_packet_append_chunk(packet, abort);
5978 /* Allocate a packet for responding in the OOTB conditions. */
5979 static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5980 const struct sctp_association *asoc,
5981 const struct sctp_chunk *chunk)
5983 struct sctp_packet *packet;
5984 struct sctp_transport *transport;
5989 /* Get the source and destination port from the inbound packet. */
5990 sport = ntohs(chunk->sctp_hdr->dest);
5991 dport = ntohs(chunk->sctp_hdr->source);
5993 /* The V-tag is going to be the same as the inbound packet if no
5994 * association exists, otherwise, use the peer's vtag.
5997 /* Special case the INIT-ACK as there is no peer's vtag
6000 switch (chunk->chunk_hdr->type) {
6001 case SCTP_CID_INIT_ACK:
6003 sctp_initack_chunk_t *initack;
6005 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6006 vtag = ntohl(initack->init_hdr.init_tag);
6010 vtag = asoc->peer.i.init_tag;
6014 /* Special case the INIT and stale COOKIE_ECHO as there is no
6017 switch (chunk->chunk_hdr->type) {
6020 sctp_init_chunk_t *init;
6022 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6023 vtag = ntohl(init->init_hdr.init_tag);
6027 vtag = ntohl(chunk->sctp_hdr->vtag);
6032 /* Make a transport for the bucket, Eliza... */
6033 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6037 /* Cache a route for the transport with the chunk's destination as
6038 * the source address.
6040 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6041 sctp_sk(net->sctp.ctl_sock));
6043 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
6044 packet = sctp_packet_config(packet, vtag, 0);
6052 /* Free the packet allocated earlier for responding in the OOTB condition. */
6053 void sctp_ootb_pkt_free(struct sctp_packet *packet)
6055 sctp_transport_free(packet->transport);
6058 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6059 static void sctp_send_stale_cookie_err(struct net *net,
6060 const struct sctp_endpoint *ep,
6061 const struct sctp_association *asoc,
6062 const struct sctp_chunk *chunk,
6063 sctp_cmd_seq_t *commands,
6064 struct sctp_chunk *err_chunk)
6066 struct sctp_packet *packet;
6069 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6071 struct sctp_signed_cookie *cookie;
6073 /* Override the OOTB vtag from the cookie. */
6074 cookie = chunk->subh.cookie_hdr;
6075 packet->vtag = cookie->c.peer_vtag;
6077 /* Set the skb to the belonging sock for accounting. */
6078 err_chunk->skb->sk = ep->base.sk;
6079 sctp_packet_append_chunk(packet, err_chunk);
6080 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6081 SCTP_PACKET(packet));
6082 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6084 sctp_chunk_free (err_chunk);
6089 /* Process a data chunk */
6090 static int sctp_eat_data(const struct sctp_association *asoc,
6091 struct sctp_chunk *chunk,
6092 sctp_cmd_seq_t *commands)
6094 sctp_datahdr_t *data_hdr;
6095 struct sctp_chunk *err;
6097 sctp_verb_t deliver;
6100 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6101 struct sock *sk = asoc->base.sk;
6102 struct net *net = sock_net(sk);
6107 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6108 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6110 tsn = ntohl(data_hdr->tsn);
6111 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6113 /* ASSERT: Now skb->data is really the user data. */
6115 /* Process ECN based congestion.
6117 * Since the chunk structure is reused for all chunks within
6118 * a packet, we use ecn_ce_done to track if we've already
6119 * done CE processing for this packet.
6121 * We need to do ECN processing even if we plan to discard the
6125 if (!chunk->ecn_ce_done) {
6127 chunk->ecn_ce_done = 1;
6129 af = sctp_get_af_specific(
6130 ipver2af(ip_hdr(chunk->skb)->version));
6132 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6133 /* Do real work as sideffect. */
6134 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6139 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6141 /* The TSN is too high--silently discard the chunk and
6142 * count on it getting retransmitted later.
6145 chunk->asoc->stats.outofseqtsns++;
6146 return SCTP_IERROR_HIGH_TSN;
6147 } else if (tmp > 0) {
6148 /* This is a duplicate. Record it. */
6149 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6150 return SCTP_IERROR_DUP_TSN;
6153 /* This is a new TSN. */
6155 /* Discard if there is no room in the receive window.
6156 * Actually, allow a little bit of overflow (up to a MTU).
6158 datalen = ntohs(chunk->chunk_hdr->length);
6159 datalen -= sizeof(sctp_data_chunk_t);
6161 deliver = SCTP_CMD_CHUNK_ULP;
6163 /* Think about partial delivery. */
6164 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6166 /* Even if we don't accept this chunk there is
6169 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6172 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6173 * seems a bit troublesome in that frag_point varies based on
6174 * PMTU. In cases, such as loopback, this might be a rather
6177 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6178 (datalen > asoc->rwnd + asoc->frag_point))) {
6180 /* If this is the next TSN, consider reneging to make
6181 * room. Note: Playing nice with a confused sender. A
6182 * malicious sender can still eat up all our buffer
6183 * space and in the future we may want to detect and
6184 * do more drastic reneging.
6186 if (sctp_tsnmap_has_gap(map) &&
6187 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6188 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6189 deliver = SCTP_CMD_RENEGE;
6191 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6192 __func__, tsn, datalen, asoc->rwnd);
6194 return SCTP_IERROR_IGNORE_TSN;
6199 * Also try to renege to limit our memory usage in the event that
6200 * we are under memory pressure
6201 * If we can't renege, don't worry about it, the sk_rmem_schedule
6202 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6203 * memory usage too much
6205 if (*sk->sk_prot_creator->memory_pressure) {
6206 if (sctp_tsnmap_has_gap(map) &&
6207 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6208 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6210 deliver = SCTP_CMD_RENEGE;
6215 * Section 3.3.10.9 No User Data (9)
6219 * No User Data: This error cause is returned to the originator of a
6220 * DATA chunk if a received DATA chunk has no user data.
6222 if (unlikely(0 == datalen)) {
6223 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6225 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6228 /* We are going to ABORT, so we might as well stop
6229 * processing the rest of the chunks in the packet.
6231 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6232 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6233 SCTP_ERROR(ECONNABORTED));
6234 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6235 SCTP_PERR(SCTP_ERROR_NO_DATA));
6236 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6237 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6238 return SCTP_IERROR_NO_DATA;
6241 chunk->data_accepted = 1;
6243 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6244 * if we renege and the chunk arrives again.
6246 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6247 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6249 chunk->asoc->stats.iuodchunks++;
6251 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6253 chunk->asoc->stats.iodchunks++;
6257 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6259 * If an endpoint receive a DATA chunk with an invalid stream
6260 * identifier, it shall acknowledge the reception of the DATA chunk
6261 * following the normal procedure, immediately send an ERROR chunk
6262 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6263 * and discard the DATA chunk.
6265 sid = ntohs(data_hdr->stream);
6266 if (sid >= asoc->c.sinit_max_instreams) {
6267 /* Mark tsn as received even though we drop it */
6268 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6270 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6272 sizeof(data_hdr->stream),
6275 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6277 return SCTP_IERROR_BAD_STREAM;
6280 /* Check to see if the SSN is possible for this TSN.
6281 * The biggest gap we can record is 4K wide. Since SSNs wrap
6282 * at an unsigned short, there is no way that an SSN can
6283 * wrap and for a valid TSN. We can simply check if the current
6284 * SSN is smaller then the next expected one. If it is, it wrapped
6287 ssn = ntohs(data_hdr->ssn);
6288 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6289 return SCTP_IERROR_PROTO_VIOLATION;
6292 /* Send the data up to the user. Note: Schedule the
6293 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6294 * chunk needs the updated rwnd.
6296 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6298 return SCTP_IERROR_NO_ERROR;