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 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
1779 (sctp_sstate(asoc->base.sk, CLOSING) ||
1780 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1781 /* if were currently in SHUTDOWN_PENDING, but the socket
1782 * has been closed by user, don't transition to ESTABLISHED.
1783 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1785 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1786 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1787 SCTP_ST_CHUNK(0), NULL,
1790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1792 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1794 return SCTP_DISPOSITION_CONSUME;
1797 sctp_chunk_free(repl);
1799 return SCTP_DISPOSITION_NOMEM;
1802 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1805 * B) In this case, both sides may be attempting to start an association
1806 * at about the same time but the peer endpoint started its INIT
1807 * after responding to the local endpoint's INIT
1809 /* This case represents an initialization collision. */
1810 static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1811 const struct sctp_endpoint *ep,
1812 const struct sctp_association *asoc,
1813 struct sctp_chunk *chunk,
1814 sctp_cmd_seq_t *commands,
1815 struct sctp_association *new_asoc)
1817 sctp_init_chunk_t *peer_init;
1818 struct sctp_chunk *repl;
1820 /* new_asoc is a brand-new association, so these are not yet
1821 * side effects--it is safe to run them here.
1823 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1824 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1828 /* Update the content of current association. */
1829 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1830 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1831 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1832 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1833 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1835 repl = sctp_make_cookie_ack(new_asoc, chunk);
1839 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1841 /* RFC 2960 5.1 Normal Establishment of an Association
1843 * D) IMPLEMENTATION NOTE: An implementation may choose to
1844 * send the Communication Up notification to the SCTP user
1845 * upon reception of a valid COOKIE ECHO chunk.
1847 * Sadly, this needs to be implemented as a side-effect, because
1848 * we are not guaranteed to have set the association id of the real
1849 * association and so these notifications need to be delayed until
1850 * the association id is allocated.
1853 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1855 /* Sockets API Draft Section 5.3.1.6
1856 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1857 * delivers this notification to inform the application that of the
1858 * peers requested adaptation layer.
1860 * This also needs to be done as a side effect for the same reason as
1863 if (asoc->peer.adaptation_ind)
1864 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1866 return SCTP_DISPOSITION_CONSUME;
1869 return SCTP_DISPOSITION_NOMEM;
1872 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1875 * C) In this case, the local endpoint's cookie has arrived late.
1876 * Before it arrived, the local endpoint sent an INIT and received an
1877 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1878 * but a new tag of its own.
1880 /* This case represents an initialization collision. */
1881 static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1882 const struct sctp_endpoint *ep,
1883 const struct sctp_association *asoc,
1884 struct sctp_chunk *chunk,
1885 sctp_cmd_seq_t *commands,
1886 struct sctp_association *new_asoc)
1888 /* The cookie should be silently discarded.
1889 * The endpoint SHOULD NOT change states and should leave
1890 * any timers running.
1892 return SCTP_DISPOSITION_DISCARD;
1895 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1899 * D) When both local and remote tags match the endpoint should always
1900 * enter the ESTABLISHED state, if it has not already done so.
1902 /* This case represents an initialization collision. */
1903 static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1904 const struct sctp_endpoint *ep,
1905 const struct sctp_association *asoc,
1906 struct sctp_chunk *chunk,
1907 sctp_cmd_seq_t *commands,
1908 struct sctp_association *new_asoc)
1910 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1911 struct sctp_chunk *repl;
1913 /* Clarification from Implementor's Guide:
1914 * D) When both local and remote tags match the endpoint should
1915 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1916 * It should stop any cookie timer that may be running and send
1920 /* Don't accidentally move back into established state. */
1921 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1922 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1923 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1924 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1925 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1926 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1927 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1930 /* RFC 2960 5.1 Normal Establishment of an Association
1932 * D) IMPLEMENTATION NOTE: An implementation may choose
1933 * to send the Communication Up notification to the
1934 * SCTP user upon reception of a valid COOKIE
1937 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1939 asoc->c.sinit_num_ostreams,
1940 asoc->c.sinit_max_instreams,
1945 /* Sockets API Draft Section 5.3.1.6
1946 * When a peer sends a Adaptation Layer Indication parameter,
1947 * SCTP delivers this notification to inform the application
1948 * that of the peers requested adaptation layer.
1950 if (asoc->peer.adaptation_ind) {
1951 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1959 repl = sctp_make_cookie_ack(new_asoc, chunk);
1963 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1966 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1969 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1970 SCTP_ULPEVENT(ai_ev));
1972 return SCTP_DISPOSITION_CONSUME;
1976 sctp_ulpevent_free(ai_ev);
1978 sctp_ulpevent_free(ev);
1979 return SCTP_DISPOSITION_NOMEM;
1983 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1984 * chunk was retransmitted and then delayed in the network.
1986 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1988 * Verification Tag: None. Do cookie validation.
1991 * (endpoint, asoc, chunk)
1994 * (asoc, reply_msg, msg_up, timers, counters)
1996 * The return value is the disposition of the chunk.
1998 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
1999 const struct sctp_endpoint *ep,
2000 const struct sctp_association *asoc,
2001 const sctp_subtype_t type,
2003 sctp_cmd_seq_t *commands)
2005 sctp_disposition_t retval;
2006 struct sctp_chunk *chunk = arg;
2007 struct sctp_association *new_asoc;
2010 struct sctp_chunk *err_chk_p;
2012 /* Make sure that the chunk has a valid length from the protocol
2013 * perspective. In this case check to make sure we have at least
2014 * enough for the chunk header. Cookie length verification is
2017 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2018 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2021 /* "Decode" the chunk. We have no optional parameters so we
2022 * are in good shape.
2024 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2025 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2026 sizeof(sctp_chunkhdr_t)))
2029 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2030 * of a duplicate COOKIE ECHO match the Verification Tags of the
2031 * current association, consider the State Cookie valid even if
2032 * the lifespan is exceeded.
2034 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2038 * If the re-build failed, what is the proper error path
2041 * [We should abort the association. --piggy]
2044 /* FIXME: Several errors are possible. A bad cookie should
2045 * be silently discarded, but think about logging it too.
2048 case -SCTP_IERROR_NOMEM:
2051 case -SCTP_IERROR_STALE_COOKIE:
2052 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2054 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2055 case -SCTP_IERROR_BAD_SIG:
2057 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2061 /* Compare the tie_tag in cookie with the verification tag of
2062 * current association.
2064 action = sctp_tietags_compare(new_asoc, asoc);
2067 case 'A': /* Association restart. */
2068 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2072 case 'B': /* Collision case B. */
2073 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2077 case 'C': /* Collision case C. */
2078 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2082 case 'D': /* Collision case D. */
2083 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2087 default: /* Discard packet for all others. */
2088 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2092 /* Delete the tempory new association. */
2093 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2094 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2096 /* Restore association pointer to provide SCTP command interpeter
2097 * with a valid context in case it needs to manipulate
2099 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2100 SCTP_ASOC((struct sctp_association *)asoc));
2105 return SCTP_DISPOSITION_NOMEM;
2109 * Process an ABORT. (SHUTDOWN-PENDING state)
2111 * See sctp_sf_do_9_1_abort().
2113 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2115 const struct sctp_endpoint *ep,
2116 const struct sctp_association *asoc,
2117 const sctp_subtype_t type,
2119 sctp_cmd_seq_t *commands)
2121 struct sctp_chunk *chunk = arg;
2123 if (!sctp_vtag_verify_either(chunk, asoc))
2124 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2126 /* Make sure that the ABORT chunk has a valid length.
2127 * Since this is an ABORT chunk, we have to discard it
2128 * because of the following text:
2129 * RFC 2960, Section 3.3.7
2130 * If an endpoint receives an ABORT with a format error or for an
2131 * association that doesn't exist, it MUST silently discard it.
2132 * Because the length is "invalid", we can't really discard just
2133 * as we do not know its true length. So, to be safe, discard the
2136 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2137 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2139 /* ADD-IP: Special case for ABORT chunks
2140 * F4) One special consideration is that ABORT Chunks arriving
2141 * destined to the IP address being deleted MUST be
2142 * ignored (see Section 5.3.1 for further details).
2144 if (SCTP_ADDR_DEL ==
2145 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2146 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2148 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2152 * Process an ABORT. (SHUTDOWN-SENT state)
2154 * See sctp_sf_do_9_1_abort().
2156 sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2157 const struct sctp_endpoint *ep,
2158 const struct sctp_association *asoc,
2159 const sctp_subtype_t type,
2161 sctp_cmd_seq_t *commands)
2163 struct sctp_chunk *chunk = arg;
2165 if (!sctp_vtag_verify_either(chunk, asoc))
2166 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2168 /* Make sure that the ABORT chunk has a valid length.
2169 * Since this is an ABORT chunk, we have to discard it
2170 * because of the following text:
2171 * RFC 2960, Section 3.3.7
2172 * If an endpoint receives an ABORT with a format error or for an
2173 * association that doesn't exist, it MUST silently discard it.
2174 * Because the length is "invalid", we can't really discard just
2175 * as we do not know its true length. So, to be safe, discard the
2178 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2179 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2181 /* ADD-IP: Special case for ABORT chunks
2182 * F4) One special consideration is that ABORT Chunks arriving
2183 * destined to the IP address being deleted MUST be
2184 * ignored (see Section 5.3.1 for further details).
2186 if (SCTP_ADDR_DEL ==
2187 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2188 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2190 /* Stop the T2-shutdown timer. */
2191 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2192 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2194 /* Stop the T5-shutdown guard timer. */
2195 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2196 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2198 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2202 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2204 * See sctp_sf_do_9_1_abort().
2206 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2208 const struct sctp_endpoint *ep,
2209 const struct sctp_association *asoc,
2210 const sctp_subtype_t type,
2212 sctp_cmd_seq_t *commands)
2214 /* The same T2 timer, so we should be able to use
2215 * common function with the SHUTDOWN-SENT state.
2217 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2221 * Handle an Error received in COOKIE_ECHOED state.
2223 * Only handle the error type of stale COOKIE Error, the other errors will
2227 * (endpoint, asoc, chunk)
2230 * (asoc, reply_msg, msg_up, timers, counters)
2232 * The return value is the disposition of the chunk.
2234 sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2235 const struct sctp_endpoint *ep,
2236 const struct sctp_association *asoc,
2237 const sctp_subtype_t type,
2239 sctp_cmd_seq_t *commands)
2241 struct sctp_chunk *chunk = arg;
2244 if (!sctp_vtag_verify(chunk, asoc))
2245 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2247 /* Make sure that the ERROR chunk has a valid length.
2248 * The parameter walking depends on this as well.
2250 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2251 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2254 /* Process the error here */
2255 /* FUTURE FIXME: When PR-SCTP related and other optional
2256 * parms are emitted, this will have to change to handle multiple
2259 sctp_walk_errors(err, chunk->chunk_hdr) {
2260 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2261 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2265 /* It is possible to have malformed error causes, and that
2266 * will cause us to end the walk early. However, since
2267 * we are discarding the packet, there should be no adverse
2270 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2274 * Handle a Stale COOKIE Error
2276 * Section: 5.2.6 Handle Stale COOKIE Error
2277 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2278 * one of the following three alternatives.
2280 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2281 * Preservative parameter requesting an extension to the lifetime of
2282 * the State Cookie. When calculating the time extension, an
2283 * implementation SHOULD use the RTT information measured based on the
2284 * previous COOKIE ECHO / ERROR exchange, and should add no more
2285 * than 1 second beyond the measured RTT, due to long State Cookie
2286 * lifetimes making the endpoint more subject to a replay attack.
2288 * Verification Tag: Not explicit, but safe to ignore.
2291 * (endpoint, asoc, chunk)
2294 * (asoc, reply_msg, msg_up, timers, counters)
2296 * The return value is the disposition of the chunk.
2298 static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2299 const struct sctp_endpoint *ep,
2300 const struct sctp_association *asoc,
2301 const sctp_subtype_t type,
2303 sctp_cmd_seq_t *commands)
2305 struct sctp_chunk *chunk = arg;
2307 sctp_cookie_preserve_param_t bht;
2309 struct sctp_chunk *reply;
2310 struct sctp_bind_addr *bp;
2311 int attempts = asoc->init_err_counter + 1;
2313 if (attempts > asoc->max_init_attempts) {
2314 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2315 SCTP_ERROR(ETIMEDOUT));
2316 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2317 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2318 return SCTP_DISPOSITION_DELETE_TCB;
2321 err = (sctp_errhdr_t *)(chunk->skb->data);
2323 /* When calculating the time extension, an implementation
2324 * SHOULD use the RTT information measured based on the
2325 * previous COOKIE ECHO / ERROR exchange, and should add no
2326 * more than 1 second beyond the measured RTT, due to long
2327 * State Cookie lifetimes making the endpoint more subject to
2329 * Measure of Staleness's unit is usec. (1/1000000 sec)
2330 * Suggested Cookie Life-span Increment's unit is msec.
2332 * In general, if you use the suggested cookie life, the value
2333 * found in the field of measure of staleness should be doubled
2334 * to give ample time to retransmit the new cookie and thus
2335 * yield a higher probability of success on the reattempt.
2337 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2338 stale = (stale * 2) / 1000;
2340 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2341 bht.param_hdr.length = htons(sizeof(bht));
2342 bht.lifespan_increment = htonl(stale);
2344 /* Build that new INIT chunk. */
2345 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2346 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2350 sctp_addto_chunk(reply, sizeof(bht), &bht);
2352 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2353 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2355 /* Stop pending T3-rtx and heartbeat timers */
2356 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2357 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2359 /* Delete non-primary peer ip addresses since we are transitioning
2360 * back to the COOKIE-WAIT state
2362 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2364 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2367 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2368 SCTP_TRANSPORT(asoc->peer.primary_path));
2370 /* Cast away the const modifier, as we want to just
2371 * rerun it through as a sideffect.
2373 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2375 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2376 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2377 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2378 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2379 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2380 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2382 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2384 return SCTP_DISPOSITION_CONSUME;
2387 return SCTP_DISPOSITION_NOMEM;
2394 * After checking the Verification Tag, the receiving endpoint shall
2395 * remove the association from its record, and shall report the
2396 * termination to its upper layer.
2398 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2399 * B) Rules for packet carrying ABORT:
2401 * - The endpoint shall always fill in the Verification Tag field of the
2402 * outbound packet with the destination endpoint's tag value if it
2405 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2406 * MUST follow the procedure described in Section 8.4.
2408 * - The receiver MUST accept the packet if the Verification Tag
2409 * matches either its own tag, OR the tag of its peer. Otherwise, the
2410 * receiver MUST silently discard the packet and take no further
2414 * (endpoint, asoc, chunk)
2417 * (asoc, reply_msg, msg_up, timers, counters)
2419 * The return value is the disposition of the chunk.
2421 sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2422 const struct sctp_endpoint *ep,
2423 const struct sctp_association *asoc,
2424 const sctp_subtype_t type,
2426 sctp_cmd_seq_t *commands)
2428 struct sctp_chunk *chunk = arg;
2430 if (!sctp_vtag_verify_either(chunk, asoc))
2431 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2433 /* Make sure that the ABORT chunk has a valid length.
2434 * Since this is an ABORT chunk, we have to discard it
2435 * because of the following text:
2436 * RFC 2960, Section 3.3.7
2437 * If an endpoint receives an ABORT with a format error or for an
2438 * association that doesn't exist, it MUST silently discard it.
2439 * Because the length is "invalid", we can't really discard just
2440 * as we do not know its true length. So, to be safe, discard the
2443 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2444 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2446 /* ADD-IP: Special case for ABORT chunks
2447 * F4) One special consideration is that ABORT Chunks arriving
2448 * destined to the IP address being deleted MUST be
2449 * ignored (see Section 5.3.1 for further details).
2451 if (SCTP_ADDR_DEL ==
2452 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2453 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2455 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2458 static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2459 const struct sctp_endpoint *ep,
2460 const struct sctp_association *asoc,
2461 const sctp_subtype_t type,
2463 sctp_cmd_seq_t *commands)
2465 struct sctp_chunk *chunk = arg;
2467 __be16 error = SCTP_ERROR_NO_ERROR;
2469 /* See if we have an error cause code in the chunk. */
2470 len = ntohs(chunk->chunk_hdr->length);
2471 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2474 sctp_walk_errors(err, chunk->chunk_hdr);
2475 if ((void *)err != (void *)chunk->chunk_end)
2476 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2478 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2481 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2482 /* ASSOC_FAILED will DELETE_TCB. */
2483 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2484 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2485 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2487 return SCTP_DISPOSITION_ABORT;
2491 * Process an ABORT. (COOKIE-WAIT state)
2493 * See sctp_sf_do_9_1_abort() above.
2495 sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2496 const struct sctp_endpoint *ep,
2497 const struct sctp_association *asoc,
2498 const sctp_subtype_t type,
2500 sctp_cmd_seq_t *commands)
2502 struct sctp_chunk *chunk = arg;
2504 __be16 error = SCTP_ERROR_NO_ERROR;
2506 if (!sctp_vtag_verify_either(chunk, asoc))
2507 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2509 /* Make sure that the ABORT chunk has a valid length.
2510 * Since this is an ABORT chunk, we have to discard it
2511 * because of the following text:
2512 * RFC 2960, Section 3.3.7
2513 * If an endpoint receives an ABORT with a format error or for an
2514 * association that doesn't exist, it MUST silently discard it.
2515 * Because the length is "invalid", we can't really discard just
2516 * as we do not know its true length. So, to be safe, discard the
2519 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2520 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2522 /* See if we have an error cause code in the chunk. */
2523 len = ntohs(chunk->chunk_hdr->length);
2524 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2525 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2527 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2532 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2534 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2535 const struct sctp_endpoint *ep,
2536 const struct sctp_association *asoc,
2537 const sctp_subtype_t type,
2539 sctp_cmd_seq_t *commands)
2541 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2543 (struct sctp_transport *)arg);
2547 * Process an ABORT. (COOKIE-ECHOED state)
2549 sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2550 const struct sctp_endpoint *ep,
2551 const struct sctp_association *asoc,
2552 const sctp_subtype_t type,
2554 sctp_cmd_seq_t *commands)
2556 /* There is a single T1 timer, so we should be able to use
2557 * common function with the COOKIE-WAIT state.
2559 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2563 * Stop T1 timer and abort association with "INIT failed".
2565 * This is common code called by several sctp_sf_*_abort() functions above.
2567 static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2568 sctp_cmd_seq_t *commands,
2569 __be16 error, int sk_err,
2570 const struct sctp_association *asoc,
2571 struct sctp_transport *transport)
2573 pr_debug("%s: ABORT received (INIT)\n", __func__);
2575 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2576 SCTP_STATE(SCTP_STATE_CLOSED));
2577 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2578 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2579 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2580 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2581 /* CMD_INIT_FAILED will DELETE_TCB. */
2582 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2585 return SCTP_DISPOSITION_ABORT;
2589 * sctp_sf_do_9_2_shut
2592 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2593 * - enter the SHUTDOWN-RECEIVED state,
2595 * - stop accepting new data from its SCTP user
2597 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2598 * that all its outstanding DATA chunks have been received by the
2601 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2602 * send a SHUTDOWN in response to a ULP request. And should discard
2603 * subsequent SHUTDOWN chunks.
2605 * If there are still outstanding DATA chunks left, the SHUTDOWN
2606 * receiver shall continue to follow normal data transmission
2607 * procedures defined in Section 6 until all outstanding DATA chunks
2608 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2609 * new data from its SCTP user.
2611 * Verification Tag: 8.5 Verification Tag [Normal verification]
2614 * (endpoint, asoc, chunk)
2617 * (asoc, reply_msg, msg_up, timers, counters)
2619 * The return value is the disposition of the chunk.
2621 sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2622 const struct sctp_endpoint *ep,
2623 const struct sctp_association *asoc,
2624 const sctp_subtype_t type,
2626 sctp_cmd_seq_t *commands)
2628 struct sctp_chunk *chunk = arg;
2629 sctp_shutdownhdr_t *sdh;
2630 sctp_disposition_t disposition;
2631 struct sctp_ulpevent *ev;
2634 if (!sctp_vtag_verify(chunk, asoc))
2635 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2637 /* Make sure that the SHUTDOWN chunk has a valid length. */
2638 if (!sctp_chunk_length_valid(chunk,
2639 sizeof(struct sctp_shutdown_chunk_t)))
2640 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2643 /* Convert the elaborate header. */
2644 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2645 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2646 chunk->subh.shutdown_hdr = sdh;
2647 ctsn = ntohl(sdh->cum_tsn_ack);
2649 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2650 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2651 asoc->ctsn_ack_point);
2653 return SCTP_DISPOSITION_DISCARD;
2656 /* If Cumulative TSN Ack beyond the max tsn currently
2657 * send, terminating the association and respond to the
2658 * sender with an ABORT.
2660 if (!TSN_lt(ctsn, asoc->next_tsn))
2661 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2663 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2664 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2665 * inform the application that it should cease sending data.
2667 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2669 disposition = SCTP_DISPOSITION_NOMEM;
2672 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2674 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2675 * - enter the SHUTDOWN-RECEIVED state,
2676 * - stop accepting new data from its SCTP user
2678 * [This is implicit in the new state.]
2680 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2681 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2682 disposition = SCTP_DISPOSITION_CONSUME;
2684 if (sctp_outq_is_empty(&asoc->outqueue)) {
2685 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2689 if (SCTP_DISPOSITION_NOMEM == disposition)
2692 /* - verify, by checking the Cumulative TSN Ack field of the
2693 * chunk, that all its outstanding DATA chunks have been
2694 * received by the SHUTDOWN sender.
2696 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2697 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2704 * sctp_sf_do_9_2_shut_ctsn
2706 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2707 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2708 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2709 * MUST be processed.
2711 sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2712 const struct sctp_endpoint *ep,
2713 const struct sctp_association *asoc,
2714 const sctp_subtype_t type,
2716 sctp_cmd_seq_t *commands)
2718 struct sctp_chunk *chunk = arg;
2719 sctp_shutdownhdr_t *sdh;
2722 if (!sctp_vtag_verify(chunk, asoc))
2723 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2725 /* Make sure that the SHUTDOWN chunk has a valid length. */
2726 if (!sctp_chunk_length_valid(chunk,
2727 sizeof(struct sctp_shutdown_chunk_t)))
2728 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2731 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2732 ctsn = ntohl(sdh->cum_tsn_ack);
2734 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2735 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2736 asoc->ctsn_ack_point);
2738 return SCTP_DISPOSITION_DISCARD;
2741 /* If Cumulative TSN Ack beyond the max tsn currently
2742 * send, terminating the association and respond to the
2743 * sender with an ABORT.
2745 if (!TSN_lt(ctsn, asoc->next_tsn))
2746 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2748 /* verify, by checking the Cumulative TSN Ack field of the
2749 * chunk, that all its outstanding DATA chunks have been
2750 * received by the SHUTDOWN sender.
2752 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2753 SCTP_BE32(sdh->cum_tsn_ack));
2755 return SCTP_DISPOSITION_CONSUME;
2759 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2760 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2761 * transport addresses (either in the IP addresses or in the INIT chunk)
2762 * that belong to this association, it should discard the INIT chunk and
2763 * retransmit the SHUTDOWN ACK chunk.
2765 sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2766 const struct sctp_endpoint *ep,
2767 const struct sctp_association *asoc,
2768 const sctp_subtype_t type,
2770 sctp_cmd_seq_t *commands)
2772 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2773 struct sctp_chunk *reply;
2775 /* Make sure that the chunk has a valid length */
2776 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2777 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2780 /* Since we are not going to really process this INIT, there
2781 * is no point in verifying chunk boundries. Just generate
2784 reply = sctp_make_shutdown_ack(asoc, chunk);
2788 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2789 * the T2-SHUTDOWN timer.
2791 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2793 /* and restart the T2-shutdown timer. */
2794 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2795 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2797 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2799 return SCTP_DISPOSITION_CONSUME;
2801 return SCTP_DISPOSITION_NOMEM;
2805 * sctp_sf_do_ecn_cwr
2807 * Section: Appendix A: Explicit Congestion Notification
2811 * RFC 2481 details a specific bit for a sender to send in the header of
2812 * its next outbound TCP segment to indicate to its peer that it has
2813 * reduced its congestion window. This is termed the CWR bit. For
2814 * SCTP the same indication is made by including the CWR chunk.
2815 * This chunk contains one data element, i.e. the TSN number that
2816 * was sent in the ECNE chunk. This element represents the lowest
2817 * TSN number in the datagram that was originally marked with the
2820 * Verification Tag: 8.5 Verification Tag [Normal verification]
2822 * (endpoint, asoc, chunk)
2825 * (asoc, reply_msg, msg_up, timers, counters)
2827 * The return value is the disposition of the chunk.
2829 sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2830 const struct sctp_endpoint *ep,
2831 const struct sctp_association *asoc,
2832 const sctp_subtype_t type,
2834 sctp_cmd_seq_t *commands)
2837 struct sctp_chunk *chunk = arg;
2840 if (!sctp_vtag_verify(chunk, asoc))
2841 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2843 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2844 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2847 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2848 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2850 lowest_tsn = ntohl(cwr->lowest_tsn);
2852 /* Does this CWR ack the last sent congestion notification? */
2853 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2854 /* Stop sending ECNE. */
2855 sctp_add_cmd_sf(commands,
2857 SCTP_U32(lowest_tsn));
2859 return SCTP_DISPOSITION_CONSUME;
2865 * Section: Appendix A: Explicit Congestion Notification
2869 * RFC 2481 details a specific bit for a receiver to send back in its
2870 * TCP acknowledgements to notify the sender of the Congestion
2871 * Experienced (CE) bit having arrived from the network. For SCTP this
2872 * same indication is made by including the ECNE chunk. This chunk
2873 * contains one data element, i.e. the lowest TSN associated with the IP
2874 * datagram marked with the CE bit.....
2876 * Verification Tag: 8.5 Verification Tag [Normal verification]
2878 * (endpoint, asoc, chunk)
2881 * (asoc, reply_msg, msg_up, timers, counters)
2883 * The return value is the disposition of the chunk.
2885 sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2886 const struct sctp_endpoint *ep,
2887 const struct sctp_association *asoc,
2888 const sctp_subtype_t type,
2890 sctp_cmd_seq_t *commands)
2892 sctp_ecnehdr_t *ecne;
2893 struct sctp_chunk *chunk = arg;
2895 if (!sctp_vtag_verify(chunk, asoc))
2896 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2898 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2899 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2902 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2903 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2905 /* If this is a newer ECNE than the last CWR packet we sent out */
2906 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2907 SCTP_U32(ntohl(ecne->lowest_tsn)));
2909 return SCTP_DISPOSITION_CONSUME;
2913 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2915 * The SCTP endpoint MUST always acknowledge the reception of each valid
2918 * The guidelines on delayed acknowledgement algorithm specified in
2919 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2920 * acknowledgement SHOULD be generated for at least every second packet
2921 * (not every second DATA chunk) received, and SHOULD be generated within
2922 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2923 * situations it may be beneficial for an SCTP transmitter to be more
2924 * conservative than the algorithms detailed in this document allow.
2925 * However, an SCTP transmitter MUST NOT be more aggressive than the
2926 * following algorithms allow.
2928 * A SCTP receiver MUST NOT generate more than one SACK for every
2929 * incoming packet, other than to update the offered window as the
2930 * receiving application consumes new data.
2932 * Verification Tag: 8.5 Verification Tag [Normal verification]
2935 * (endpoint, asoc, chunk)
2938 * (asoc, reply_msg, msg_up, timers, counters)
2940 * The return value is the disposition of the chunk.
2942 sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2943 const struct sctp_endpoint *ep,
2944 const struct sctp_association *asoc,
2945 const sctp_subtype_t type,
2947 sctp_cmd_seq_t *commands)
2949 struct sctp_chunk *chunk = arg;
2950 sctp_arg_t force = SCTP_NOFORCE();
2953 if (!sctp_vtag_verify(chunk, asoc)) {
2954 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2956 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2959 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2960 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2963 error = sctp_eat_data(asoc, chunk, commands);
2965 case SCTP_IERROR_NO_ERROR:
2967 case SCTP_IERROR_HIGH_TSN:
2968 case SCTP_IERROR_BAD_STREAM:
2969 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2970 goto discard_noforce;
2971 case SCTP_IERROR_DUP_TSN:
2972 case SCTP_IERROR_IGNORE_TSN:
2973 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2975 case SCTP_IERROR_NO_DATA:
2977 case SCTP_IERROR_PROTO_VIOLATION:
2978 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
2979 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
2984 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2985 force = SCTP_FORCE();
2987 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
2988 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2989 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2992 /* If this is the last chunk in a packet, we need to count it
2993 * toward sack generation. Note that we need to SACK every
2994 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2995 * THEM. We elect to NOT generate SACK's if the chunk fails
2996 * the verification tag test.
2998 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3000 * The SCTP endpoint MUST always acknowledge the reception of
3001 * each valid DATA chunk.
3003 * The guidelines on delayed acknowledgement algorithm
3004 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3005 * Specifically, an acknowledgement SHOULD be generated for at
3006 * least every second packet (not every second DATA chunk)
3007 * received, and SHOULD be generated within 200 ms of the
3008 * arrival of any unacknowledged DATA chunk. In some
3009 * situations it may be beneficial for an SCTP transmitter to
3010 * be more conservative than the algorithms detailed in this
3011 * document allow. However, an SCTP transmitter MUST NOT be
3012 * more aggressive than the following algorithms allow.
3014 if (chunk->end_of_packet)
3015 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3017 return SCTP_DISPOSITION_CONSUME;
3020 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3022 * When a packet arrives with duplicate DATA chunk(s) and with
3023 * no new DATA chunk(s), the endpoint MUST immediately send a
3024 * SACK with no delay. If a packet arrives with duplicate
3025 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3026 * MAY immediately send a SACK. Normally receipt of duplicate
3027 * DATA chunks will occur when the original SACK chunk was lost
3028 * and the peer's RTO has expired. The duplicate TSN number(s)
3029 * SHOULD be reported in the SACK as duplicate.
3031 /* In our case, we split the MAY SACK advice up whether or not
3032 * the last chunk is a duplicate.'
3034 if (chunk->end_of_packet)
3035 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3036 return SCTP_DISPOSITION_DISCARD;
3039 if (chunk->end_of_packet)
3040 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3042 return SCTP_DISPOSITION_DISCARD;
3044 return SCTP_DISPOSITION_CONSUME;
3049 * sctp_sf_eat_data_fast_4_4
3052 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3053 * DATA chunks without delay.
3055 * Verification Tag: 8.5 Verification Tag [Normal verification]
3057 * (endpoint, asoc, chunk)
3060 * (asoc, reply_msg, msg_up, timers, counters)
3062 * The return value is the disposition of the chunk.
3064 sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3065 const struct sctp_endpoint *ep,
3066 const struct sctp_association *asoc,
3067 const sctp_subtype_t type,
3069 sctp_cmd_seq_t *commands)
3071 struct sctp_chunk *chunk = arg;
3074 if (!sctp_vtag_verify(chunk, asoc)) {
3075 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3077 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3080 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3081 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3084 error = sctp_eat_data(asoc, chunk, commands);
3086 case SCTP_IERROR_NO_ERROR:
3087 case SCTP_IERROR_HIGH_TSN:
3088 case SCTP_IERROR_DUP_TSN:
3089 case SCTP_IERROR_IGNORE_TSN:
3090 case SCTP_IERROR_BAD_STREAM:
3092 case SCTP_IERROR_NO_DATA:
3094 case SCTP_IERROR_PROTO_VIOLATION:
3095 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3096 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3101 /* Go a head and force a SACK, since we are shutting down. */
3103 /* Implementor's Guide.
3105 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3106 * respond to each received packet containing one or more DATA chunk(s)
3107 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3109 if (chunk->end_of_packet) {
3110 /* We must delay the chunk creation since the cumulative
3111 * TSN has not been updated yet.
3113 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3114 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3115 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3116 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3120 return SCTP_DISPOSITION_CONSUME;
3124 * Section: 6.2 Processing a Received SACK
3125 * D) Any time a SACK arrives, the endpoint performs the following:
3127 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3128 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3129 * increasing, a SACK whose Cumulative TSN Ack is less than the
3130 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3132 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3133 * of bytes still outstanding after processing the Cumulative TSN Ack
3134 * and the Gap Ack Blocks.
3136 * iii) If the SACK is missing a TSN that was previously
3137 * acknowledged via a Gap Ack Block (e.g., the data receiver
3138 * reneged on the data), then mark the corresponding DATA chunk
3139 * as available for retransmit: Mark it as missing for fast
3140 * retransmit as described in Section 7.2.4 and if no retransmit
3141 * timer is running for the destination address to which the DATA
3142 * chunk was originally transmitted, then T3-rtx is started for
3143 * that destination address.
3145 * Verification Tag: 8.5 Verification Tag [Normal verification]
3148 * (endpoint, asoc, chunk)
3151 * (asoc, reply_msg, msg_up, timers, counters)
3153 * The return value is the disposition of the chunk.
3155 sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3156 const struct sctp_endpoint *ep,
3157 const struct sctp_association *asoc,
3158 const sctp_subtype_t type,
3160 sctp_cmd_seq_t *commands)
3162 struct sctp_chunk *chunk = arg;
3163 sctp_sackhdr_t *sackh;
3166 if (!sctp_vtag_verify(chunk, asoc))
3167 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3169 /* Make sure that the SACK chunk has a valid length. */
3170 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3171 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3174 /* Pull the SACK chunk from the data buffer */
3175 sackh = sctp_sm_pull_sack(chunk);
3176 /* Was this a bogus SACK? */
3178 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3179 chunk->subh.sack_hdr = sackh;
3180 ctsn = ntohl(sackh->cum_tsn_ack);
3182 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3183 * Ack Point, then drop the SACK. Since Cumulative TSN
3184 * Ack is monotonically increasing, a SACK whose
3185 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3186 * Point indicates an out-of-order SACK.
3188 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3189 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3190 asoc->ctsn_ack_point);
3192 return SCTP_DISPOSITION_DISCARD;
3195 /* If Cumulative TSN Ack beyond the max tsn currently
3196 * send, terminating the association and respond to the
3197 * sender with an ABORT.
3199 if (!TSN_lt(ctsn, asoc->next_tsn))
3200 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3202 /* Return this SACK for further processing. */
3203 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3205 /* Note: We do the rest of the work on the PROCESS_SACK
3208 return SCTP_DISPOSITION_CONSUME;
3212 * Generate an ABORT in response to a packet.
3214 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3216 * 8) The receiver should respond to the sender of the OOTB packet with
3217 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3218 * MUST fill in the Verification Tag field of the outbound packet
3219 * with the value found in the Verification Tag field of the OOTB
3220 * packet and set the T-bit in the Chunk Flags to indicate that the
3221 * Verification Tag is reflected. After sending this ABORT, the
3222 * receiver of the OOTB packet shall discard the OOTB packet and take
3223 * no further action.
3227 * The return value is the disposition of the chunk.
3229 static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3230 const struct sctp_endpoint *ep,
3231 const struct sctp_association *asoc,
3232 const sctp_subtype_t type,
3234 sctp_cmd_seq_t *commands)
3236 struct sctp_packet *packet = NULL;
3237 struct sctp_chunk *chunk = arg;
3238 struct sctp_chunk *abort;
3240 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3243 /* Make an ABORT. The T bit will be set if the asoc
3246 abort = sctp_make_abort(asoc, chunk, 0);
3248 sctp_ootb_pkt_free(packet);
3249 return SCTP_DISPOSITION_NOMEM;
3252 /* Reflect vtag if T-Bit is set */
3253 if (sctp_test_T_bit(abort))
3254 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3256 /* Set the skb to the belonging sock for accounting. */
3257 abort->skb->sk = ep->base.sk;
3259 sctp_packet_append_chunk(packet, abort);
3261 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3262 SCTP_PACKET(packet));
3264 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3266 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3267 return SCTP_DISPOSITION_CONSUME;
3270 return SCTP_DISPOSITION_NOMEM;
3274 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3275 * event as ULP notification for each cause included in the chunk.
3277 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3279 * The return value is the disposition of the chunk.
3281 sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3282 const struct sctp_endpoint *ep,
3283 const struct sctp_association *asoc,
3284 const sctp_subtype_t type,
3286 sctp_cmd_seq_t *commands)
3288 struct sctp_chunk *chunk = arg;
3291 if (!sctp_vtag_verify(chunk, asoc))
3292 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3294 /* Make sure that the ERROR chunk has a valid length. */
3295 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3296 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3298 sctp_walk_errors(err, chunk->chunk_hdr);
3299 if ((void *)err != (void *)chunk->chunk_end)
3300 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3301 (void *)err, commands);
3303 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3306 return SCTP_DISPOSITION_CONSUME;
3310 * Process an inbound SHUTDOWN ACK.
3313 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3314 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3315 * peer, and remove all record of the association.
3317 * The return value is the disposition.
3319 sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3320 const struct sctp_endpoint *ep,
3321 const struct sctp_association *asoc,
3322 const sctp_subtype_t type,
3324 sctp_cmd_seq_t *commands)
3326 struct sctp_chunk *chunk = arg;
3327 struct sctp_chunk *reply;
3328 struct sctp_ulpevent *ev;
3330 if (!sctp_vtag_verify(chunk, asoc))
3331 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3333 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3334 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3335 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3337 /* 10.2 H) SHUTDOWN COMPLETE notification
3339 * When SCTP completes the shutdown procedures (section 9.2) this
3340 * notification is passed to the upper layer.
3342 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3343 0, 0, 0, NULL, GFP_ATOMIC);
3347 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3348 reply = sctp_make_shutdown_complete(asoc, chunk);
3352 /* Do all the commands now (after allocation), so that we
3353 * have consistent state if memory allocation failes
3355 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3357 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3358 * stop the T2-shutdown timer,
3360 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3361 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3364 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3366 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3367 SCTP_STATE(SCTP_STATE_CLOSED));
3368 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3369 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3370 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3372 /* ...and remove all record of the association. */
3373 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3374 return SCTP_DISPOSITION_DELETE_TCB;
3377 sctp_ulpevent_free(ev);
3379 return SCTP_DISPOSITION_NOMEM;
3383 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3385 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3386 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3387 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3388 * packet must fill in the Verification Tag field of the outbound
3389 * packet with the Verification Tag received in the SHUTDOWN ACK and
3390 * set the T-bit in the Chunk Flags to indicate that the Verification
3393 * 8) The receiver should respond to the sender of the OOTB packet with
3394 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3395 * MUST fill in the Verification Tag field of the outbound packet
3396 * with the value found in the Verification Tag field of the OOTB
3397 * packet and set the T-bit in the Chunk Flags to indicate that the
3398 * Verification Tag is reflected. After sending this ABORT, the
3399 * receiver of the OOTB packet shall discard the OOTB packet and take
3400 * no further action.
3402 sctp_disposition_t sctp_sf_ootb(struct net *net,
3403 const struct sctp_endpoint *ep,
3404 const struct sctp_association *asoc,
3405 const sctp_subtype_t type,
3407 sctp_cmd_seq_t *commands)
3409 struct sctp_chunk *chunk = arg;
3410 struct sk_buff *skb = chunk->skb;
3411 sctp_chunkhdr_t *ch;
3414 int ootb_shut_ack = 0;
3415 int ootb_cookie_ack = 0;
3417 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3419 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3421 /* Report violation if the chunk is less then minimal */
3422 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3423 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3426 /* Now that we know we at least have a chunk header,
3427 * do things that are type appropriate.
3429 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3432 /* RFC 2960, Section 3.3.7
3433 * Moreover, under any circumstances, an endpoint that
3434 * receives an ABORT MUST NOT respond to that ABORT by
3435 * sending an ABORT of its own.
3437 if (SCTP_CID_ABORT == ch->type)
3438 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3440 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3441 * or a COOKIE ACK the SCTP Packet should be silently
3445 if (SCTP_CID_COOKIE_ACK == ch->type)
3446 ootb_cookie_ack = 1;
3448 if (SCTP_CID_ERROR == ch->type) {
3449 sctp_walk_errors(err, ch) {
3450 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3451 ootb_cookie_ack = 1;
3457 /* Report violation if chunk len overflows */
3458 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3459 if (ch_end > skb_tail_pointer(skb))
3460 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3463 ch = (sctp_chunkhdr_t *) ch_end;
3464 } while (ch_end < skb_tail_pointer(skb));
3467 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3468 else if (ootb_cookie_ack)
3469 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3471 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3475 * Handle an "Out of the blue" SHUTDOWN ACK.
3477 * Section: 8.4 5, sctpimpguide 2.41.
3479 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3480 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3481 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3482 * packet must fill in the Verification Tag field of the outbound
3483 * packet with the Verification Tag received in the SHUTDOWN ACK and
3484 * set the T-bit in the Chunk Flags to indicate that the Verification
3488 * (endpoint, asoc, type, arg, commands)
3491 * (sctp_disposition_t)
3493 * The return value is the disposition of the chunk.
3495 static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3496 const struct sctp_endpoint *ep,
3497 const struct sctp_association *asoc,
3498 const sctp_subtype_t type,
3500 sctp_cmd_seq_t *commands)
3502 struct sctp_packet *packet = NULL;
3503 struct sctp_chunk *chunk = arg;
3504 struct sctp_chunk *shut;
3506 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3509 /* Make an SHUTDOWN_COMPLETE.
3510 * The T bit will be set if the asoc is NULL.
3512 shut = sctp_make_shutdown_complete(asoc, chunk);
3514 sctp_ootb_pkt_free(packet);
3515 return SCTP_DISPOSITION_NOMEM;
3518 /* Reflect vtag if T-Bit is set */
3519 if (sctp_test_T_bit(shut))
3520 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3522 /* Set the skb to the belonging sock for accounting. */
3523 shut->skb->sk = ep->base.sk;
3525 sctp_packet_append_chunk(packet, shut);
3527 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3528 SCTP_PACKET(packet));
3530 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3532 /* If the chunk length is invalid, we don't want to process
3533 * the reset of the packet.
3535 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3536 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3538 /* We need to discard the rest of the packet to prevent
3539 * potential bomming attacks from additional bundled chunks.
3540 * This is documented in SCTP Threats ID.
3542 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3545 return SCTP_DISPOSITION_NOMEM;
3549 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3551 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3552 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3553 * procedures in section 8.4 SHOULD be followed, in other words it
3554 * should be treated as an Out Of The Blue packet.
3555 * [This means that we do NOT check the Verification Tag on these
3559 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3560 const struct sctp_endpoint *ep,
3561 const struct sctp_association *asoc,
3562 const sctp_subtype_t type,
3564 sctp_cmd_seq_t *commands)
3566 struct sctp_chunk *chunk = arg;
3568 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3569 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3570 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3573 /* Although we do have an association in this case, it corresponds
3574 * to a restarted association. So the packet is treated as an OOTB
3575 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3576 * called with a NULL association.
3578 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3580 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3583 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3584 sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3585 const struct sctp_endpoint *ep,
3586 const struct sctp_association *asoc,
3587 const sctp_subtype_t type, void *arg,
3588 sctp_cmd_seq_t *commands)
3590 struct sctp_chunk *chunk = arg;
3591 struct sctp_chunk *asconf_ack = NULL;
3592 struct sctp_paramhdr *err_param = NULL;
3593 sctp_addiphdr_t *hdr;
3594 union sctp_addr_param *addr_param;
3598 if (!sctp_vtag_verify(chunk, asoc)) {
3599 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3601 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3604 /* ADD-IP: Section 4.1.1
3605 * This chunk MUST be sent in an authenticated way by using
3606 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3607 * is received unauthenticated it MUST be silently discarded as
3608 * described in [I-D.ietf-tsvwg-sctp-auth].
3610 if (!net->sctp.addip_noauth && !chunk->auth)
3611 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3613 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3614 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3615 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3618 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3619 serial = ntohl(hdr->serial);
3621 addr_param = (union sctp_addr_param *)hdr->params;
3622 length = ntohs(addr_param->p.length);
3623 if (length < sizeof(sctp_paramhdr_t))
3624 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3625 (void *)addr_param, commands);
3627 /* Verify the ASCONF chunk before processing it. */
3628 if (!sctp_verify_asconf(asoc,
3629 (sctp_paramhdr_t *)((void *)addr_param + length),
3630 (void *)chunk->chunk_end,
3632 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3633 (void *)err_param, commands);
3635 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3636 * the endpoint stored in a new association variable
3637 * 'Peer-Serial-Number'.
3639 if (serial == asoc->peer.addip_serial + 1) {
3640 /* If this is the first instance of ASCONF in the packet,
3641 * we can clean our old ASCONF-ACKs.
3643 if (!chunk->has_asconf)
3644 sctp_assoc_clean_asconf_ack_cache(asoc);
3646 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3647 * expected, process the ASCONF as described below and after
3648 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3649 * the response packet and cache a copy of it (in the event it
3650 * later needs to be retransmitted).
3652 * Essentially, do V1-V5.
3654 asconf_ack = sctp_process_asconf((struct sctp_association *)
3657 return SCTP_DISPOSITION_NOMEM;
3658 } else if (serial < asoc->peer.addip_serial + 1) {
3660 * If the value found in the Sequence Number is less than the
3661 * ('Peer- Sequence-Number' + 1), simply skip to the next
3662 * ASCONF, and include in the outbound response packet
3663 * any previously cached ASCONF-ACK response that was
3664 * sent and saved that matches the Sequence Number of the
3665 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3666 * Chunk exists. This will occur when an older ASCONF
3667 * arrives out of order. In such a case, the receiver
3668 * should skip the ASCONF Chunk and not include ASCONF-ACK
3669 * Chunk for that chunk.
3671 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3673 return SCTP_DISPOSITION_DISCARD;
3675 /* Reset the transport so that we select the correct one
3676 * this time around. This is to make sure that we don't
3677 * accidentally use a stale transport that's been removed.
3679 asconf_ack->transport = NULL;
3681 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3682 * it must be either a stale packet or from an attacker.
3684 return SCTP_DISPOSITION_DISCARD;
3687 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3688 * containing the ASCONF-ACK Chunks MUST be the source address of
3689 * the SCTP packet that held the ASCONF Chunks.
3691 * To do this properly, we'll set the destination address of the chunk
3692 * and at the transmit time, will try look up the transport to use.
3693 * Since ASCONFs may be bundled, the correct transport may not be
3694 * created until we process the entire packet, thus this workaround.
3696 asconf_ack->dest = chunk->source;
3697 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3698 if (asoc->new_transport) {
3699 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3700 ((struct sctp_association *)asoc)->new_transport = NULL;
3703 return SCTP_DISPOSITION_CONSUME;
3707 * ADDIP Section 4.3 General rules for address manipulation
3708 * When building TLV parameters for the ASCONF Chunk that will add or
3709 * delete IP addresses the D0 to D13 rules should be applied:
3711 sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3712 const struct sctp_endpoint *ep,
3713 const struct sctp_association *asoc,
3714 const sctp_subtype_t type, void *arg,
3715 sctp_cmd_seq_t *commands)
3717 struct sctp_chunk *asconf_ack = arg;
3718 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3719 struct sctp_chunk *abort;
3720 struct sctp_paramhdr *err_param = NULL;
3721 sctp_addiphdr_t *addip_hdr;
3722 __u32 sent_serial, rcvd_serial;
3724 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3725 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3727 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3730 /* ADD-IP, Section 4.1.2:
3731 * This chunk MUST be sent in an authenticated way by using
3732 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3733 * is received unauthenticated it MUST be silently discarded as
3734 * described in [I-D.ietf-tsvwg-sctp-auth].
3736 if (!net->sctp.addip_noauth && !asconf_ack->auth)
3737 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3739 /* Make sure that the ADDIP chunk has a valid length. */
3740 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3741 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3744 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3745 rcvd_serial = ntohl(addip_hdr->serial);
3747 /* Verify the ASCONF-ACK chunk before processing it. */
3748 if (!sctp_verify_asconf(asoc,
3749 (sctp_paramhdr_t *)addip_hdr->params,
3750 (void *)asconf_ack->chunk_end,
3752 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3753 (void *)err_param, commands);
3756 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3757 sent_serial = ntohl(addip_hdr->serial);
3759 sent_serial = asoc->addip_serial - 1;
3762 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3763 * equal to the next serial number to be used but no ASCONF chunk is
3764 * outstanding the endpoint MUST ABORT the association. Note that a
3765 * sequence number is greater than if it is no more than 2^^31-1
3766 * larger than the current sequence number (using serial arithmetic).
3768 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3769 !(asoc->addip_last_asconf)) {
3770 abort = sctp_make_abort(asoc, asconf_ack,
3771 sizeof(sctp_errhdr_t));
3773 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3774 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3777 /* We are going to ABORT, so we might as well stop
3778 * processing the rest of the chunks in the packet.
3780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3781 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3782 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3783 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3784 SCTP_ERROR(ECONNABORTED));
3785 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3786 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3787 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3788 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3789 return SCTP_DISPOSITION_ABORT;
3792 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3793 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3794 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3796 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3798 /* Successfully processed ASCONF_ACK. We can
3799 * release the next asconf if we have one.
3801 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3803 return SCTP_DISPOSITION_CONSUME;
3806 abort = sctp_make_abort(asoc, asconf_ack,
3807 sizeof(sctp_errhdr_t));
3809 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3810 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3813 /* We are going to ABORT, so we might as well stop
3814 * processing the rest of the chunks in the packet.
3816 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3817 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3818 SCTP_ERROR(ECONNABORTED));
3819 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3820 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3821 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3822 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3823 return SCTP_DISPOSITION_ABORT;
3826 return SCTP_DISPOSITION_DISCARD;
3830 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3832 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3833 * its cumulative TSN point to the value carried in the FORWARD TSN
3834 * chunk, and then MUST further advance its cumulative TSN point locally
3836 * After the above processing, the data receiver MUST stop reporting any
3837 * missing TSNs earlier than or equal to the new cumulative TSN point.
3839 * Verification Tag: 8.5 Verification Tag [Normal verification]
3841 * The return value is the disposition of the chunk.
3843 sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3844 const struct sctp_endpoint *ep,
3845 const struct sctp_association *asoc,
3846 const sctp_subtype_t type,
3848 sctp_cmd_seq_t *commands)
3850 struct sctp_chunk *chunk = arg;
3851 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3852 struct sctp_fwdtsn_skip *skip;
3856 if (!sctp_vtag_verify(chunk, asoc)) {
3857 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3859 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3862 /* Make sure that the FORWARD_TSN chunk has valid length. */
3863 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3864 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3867 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3868 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3869 len = ntohs(chunk->chunk_hdr->length);
3870 len -= sizeof(struct sctp_chunkhdr);
3871 skb_pull(chunk->skb, len);
3873 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3874 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3876 /* The TSN is too high--silently discard the chunk and count on it
3877 * getting retransmitted later.
3879 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3880 goto discard_noforce;
3882 /* Silently discard the chunk if stream-id is not valid */
3883 sctp_walk_fwdtsn(skip, chunk) {
3884 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3885 goto discard_noforce;
3888 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3889 if (len > sizeof(struct sctp_fwdtsn_hdr))
3890 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3893 /* Count this as receiving DATA. */
3894 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3895 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3896 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3899 /* FIXME: For now send a SACK, but DATA processing may
3902 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3904 return SCTP_DISPOSITION_CONSUME;
3907 return SCTP_DISPOSITION_DISCARD;
3910 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3912 const struct sctp_endpoint *ep,
3913 const struct sctp_association *asoc,
3914 const sctp_subtype_t type,
3916 sctp_cmd_seq_t *commands)
3918 struct sctp_chunk *chunk = arg;
3919 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3920 struct sctp_fwdtsn_skip *skip;
3924 if (!sctp_vtag_verify(chunk, asoc)) {
3925 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3927 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3930 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3931 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3932 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3935 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3936 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3937 len = ntohs(chunk->chunk_hdr->length);
3938 len -= sizeof(struct sctp_chunkhdr);
3939 skb_pull(chunk->skb, len);
3941 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3942 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3944 /* The TSN is too high--silently discard the chunk and count on it
3945 * getting retransmitted later.
3947 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3950 /* Silently discard the chunk if stream-id is not valid */
3951 sctp_walk_fwdtsn(skip, chunk) {
3952 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3956 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3957 if (len > sizeof(struct sctp_fwdtsn_hdr))
3958 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3961 /* Go a head and force a SACK, since we are shutting down. */
3963 /* Implementor's Guide.
3965 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3966 * respond to each received packet containing one or more DATA chunk(s)
3967 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3969 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3970 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3971 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3972 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3974 return SCTP_DISPOSITION_CONSUME;
3978 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3980 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3981 * Identifier field. If this algorithm was not specified by the
3982 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3983 * during association setup, the AUTH chunk and all chunks after it MUST
3984 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3985 * defined in Section 4.1.
3987 * If an endpoint with no shared key receives a Shared Key Identifier
3988 * other than 0, it MUST silently discard all authenticated chunks. If
3989 * the endpoint has at least one endpoint pair shared key for the peer,
3990 * it MUST use the key specified by the Shared Key Identifier if a
3991 * key has been configured for that Shared Key Identifier. If no
3992 * endpoint pair shared key has been configured for that Shared Key
3993 * Identifier, all authenticated chunks MUST be silently discarded.
3995 * Verification Tag: 8.5 Verification Tag [Normal verification]
3997 * The return value is the disposition of the chunk.
3999 static sctp_ierror_t sctp_sf_authenticate(struct net *net,
4000 const struct sctp_endpoint *ep,
4001 const struct sctp_association *asoc,
4002 const sctp_subtype_t type,
4003 struct sctp_chunk *chunk)
4005 struct sctp_authhdr *auth_hdr;
4006 struct sctp_hmac *hmac;
4007 unsigned int sig_len;
4012 /* Pull in the auth header, so we can do some more verification */
4013 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4014 chunk->subh.auth_hdr = auth_hdr;
4015 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4017 /* Make sure that we support the HMAC algorithm from the auth
4020 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4021 return SCTP_IERROR_AUTH_BAD_HMAC;
4023 /* Make sure that the provided shared key identifier has been
4026 key_id = ntohs(auth_hdr->shkey_id);
4027 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4028 return SCTP_IERROR_AUTH_BAD_KEYID;
4031 /* Make sure that the length of the signature matches what
4034 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4035 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4036 if (sig_len != hmac->hmac_len)
4037 return SCTP_IERROR_PROTO_VIOLATION;
4039 /* Now that we've done validation checks, we can compute and
4040 * verify the hmac. The steps involved are:
4041 * 1. Save the digest from the chunk.
4042 * 2. Zero out the digest in the chunk.
4043 * 3. Compute the new digest
4044 * 4. Compare saved and new digests.
4046 digest = auth_hdr->hmac;
4047 skb_pull(chunk->skb, sig_len);
4049 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4053 memset(digest, 0, sig_len);
4055 sctp_auth_calculate_hmac(asoc, chunk->skb,
4056 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4059 /* Discard the packet if the digests do not match */
4060 if (memcmp(save_digest, digest, sig_len)) {
4062 return SCTP_IERROR_BAD_SIG;
4068 return SCTP_IERROR_NO_ERROR;
4070 return SCTP_IERROR_NOMEM;
4073 sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4074 const struct sctp_endpoint *ep,
4075 const struct sctp_association *asoc,
4076 const sctp_subtype_t type,
4078 sctp_cmd_seq_t *commands)
4080 struct sctp_authhdr *auth_hdr;
4081 struct sctp_chunk *chunk = arg;
4082 struct sctp_chunk *err_chunk;
4083 sctp_ierror_t error;
4085 /* Make sure that the peer has AUTH capable */
4086 if (!asoc->peer.auth_capable)
4087 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4089 if (!sctp_vtag_verify(chunk, asoc)) {
4090 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4092 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4095 /* Make sure that the AUTH chunk has valid length. */
4096 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4097 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4100 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4101 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
4103 case SCTP_IERROR_AUTH_BAD_HMAC:
4104 /* Generate the ERROR chunk and discard the rest
4107 err_chunk = sctp_make_op_error(asoc, chunk,
4108 SCTP_ERROR_UNSUP_HMAC,
4112 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4113 SCTP_CHUNK(err_chunk));
4116 case SCTP_IERROR_AUTH_BAD_KEYID:
4117 case SCTP_IERROR_BAD_SIG:
4118 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4120 case SCTP_IERROR_PROTO_VIOLATION:
4121 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4124 case SCTP_IERROR_NOMEM:
4125 return SCTP_DISPOSITION_NOMEM;
4127 default: /* Prevent gcc warnings */
4131 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4132 struct sctp_ulpevent *ev;
4134 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4135 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4140 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4144 return SCTP_DISPOSITION_CONSUME;
4148 * Process an unknown chunk.
4150 * Section: 3.2. Also, 2.1 in the implementor's guide.
4152 * Chunk Types are encoded such that the highest-order two bits specify
4153 * the action that must be taken if the processing endpoint does not
4154 * recognize the Chunk Type.
4156 * 00 - Stop processing this SCTP packet and discard it, do not process
4157 * any further chunks within it.
4159 * 01 - Stop processing this SCTP packet and discard it, do not process
4160 * any further chunks within it, and report the unrecognized
4161 * chunk in an 'Unrecognized Chunk Type'.
4163 * 10 - Skip this chunk and continue processing.
4165 * 11 - Skip this chunk and continue processing, but report in an ERROR
4166 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4168 * The return value is the disposition of the chunk.
4170 sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4171 const struct sctp_endpoint *ep,
4172 const struct sctp_association *asoc,
4173 const sctp_subtype_t type,
4175 sctp_cmd_seq_t *commands)
4177 struct sctp_chunk *unk_chunk = arg;
4178 struct sctp_chunk *err_chunk;
4179 sctp_chunkhdr_t *hdr;
4181 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4183 if (!sctp_vtag_verify(unk_chunk, asoc))
4184 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4186 /* Make sure that the chunk has a valid length.
4187 * Since we don't know the chunk type, we use a general
4188 * chunkhdr structure to make a comparison.
4190 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4191 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4194 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4195 case SCTP_CID_ACTION_DISCARD:
4196 /* Discard the packet. */
4197 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4199 case SCTP_CID_ACTION_DISCARD_ERR:
4200 /* Generate an ERROR chunk as response. */
4201 hdr = unk_chunk->chunk_hdr;
4202 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4203 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4204 WORD_ROUND(ntohs(hdr->length)),
4207 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4208 SCTP_CHUNK(err_chunk));
4211 /* Discard the packet. */
4212 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4213 return SCTP_DISPOSITION_CONSUME;
4215 case SCTP_CID_ACTION_SKIP:
4216 /* Skip the chunk. */
4217 return SCTP_DISPOSITION_DISCARD;
4219 case SCTP_CID_ACTION_SKIP_ERR:
4220 /* Generate an ERROR chunk as response. */
4221 hdr = unk_chunk->chunk_hdr;
4222 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4223 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4224 WORD_ROUND(ntohs(hdr->length)),
4227 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4228 SCTP_CHUNK(err_chunk));
4230 /* Skip the chunk. */
4231 return SCTP_DISPOSITION_CONSUME;
4237 return SCTP_DISPOSITION_DISCARD;
4241 * Discard the chunk.
4243 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4244 * [Too numerous to mention...]
4245 * Verification Tag: No verification needed.
4247 * (endpoint, asoc, chunk)
4250 * (asoc, reply_msg, msg_up, timers, counters)
4252 * The return value is the disposition of the chunk.
4254 sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4255 const struct sctp_endpoint *ep,
4256 const struct sctp_association *asoc,
4257 const sctp_subtype_t type,
4259 sctp_cmd_seq_t *commands)
4261 struct sctp_chunk *chunk = arg;
4263 /* Make sure that the chunk has a valid length.
4264 * Since we don't know the chunk type, we use a general
4265 * chunkhdr structure to make a comparison.
4267 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4268 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4271 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4273 return SCTP_DISPOSITION_DISCARD;
4277 * Discard the whole packet.
4281 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4282 * silently discard the OOTB packet and take no further action.
4284 * Verification Tag: No verification necessary
4287 * (endpoint, asoc, chunk)
4290 * (asoc, reply_msg, msg_up, timers, counters)
4292 * The return value is the disposition of the chunk.
4294 sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4295 const struct sctp_endpoint *ep,
4296 const struct sctp_association *asoc,
4297 const sctp_subtype_t type,
4299 sctp_cmd_seq_t *commands)
4301 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4302 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4304 return SCTP_DISPOSITION_CONSUME;
4309 * The other end is violating protocol.
4311 * Section: Not specified
4312 * Verification Tag: Not specified
4314 * (endpoint, asoc, chunk)
4317 * (asoc, reply_msg, msg_up, timers, counters)
4319 * We simply tag the chunk as a violation. The state machine will log
4320 * the violation and continue.
4322 sctp_disposition_t sctp_sf_violation(struct net *net,
4323 const struct sctp_endpoint *ep,
4324 const struct sctp_association *asoc,
4325 const sctp_subtype_t type,
4327 sctp_cmd_seq_t *commands)
4329 struct sctp_chunk *chunk = arg;
4331 /* Make sure that the chunk has a valid length. */
4332 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4333 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4336 return SCTP_DISPOSITION_VIOLATION;
4340 * Common function to handle a protocol violation.
4342 static sctp_disposition_t sctp_sf_abort_violation(
4344 const struct sctp_endpoint *ep,
4345 const struct sctp_association *asoc,
4347 sctp_cmd_seq_t *commands,
4348 const __u8 *payload,
4349 const size_t paylen)
4351 struct sctp_packet *packet = NULL;
4352 struct sctp_chunk *chunk = arg;
4353 struct sctp_chunk *abort = NULL;
4355 /* SCTP-AUTH, Section 6.3:
4356 * It should be noted that if the receiver wants to tear
4357 * down an association in an authenticated way only, the
4358 * handling of malformed packets should not result in
4359 * tearing down the association.
4361 * This means that if we only want to abort associations
4362 * in an authenticated way (i.e AUTH+ABORT), then we
4363 * can't destroy this association just because the packet
4366 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4369 /* Make the abort chunk. */
4370 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4375 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4376 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4377 !asoc->peer.i.init_tag) {
4378 sctp_initack_chunk_t *initack;
4380 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4381 if (!sctp_chunk_length_valid(chunk,
4382 sizeof(sctp_initack_chunk_t)))
4383 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4385 unsigned int inittag;
4387 inittag = ntohl(initack->init_hdr.init_tag);
4388 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4393 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4394 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4396 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4397 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4398 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4399 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4400 SCTP_ERROR(ECONNREFUSED));
4401 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4402 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4404 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4405 SCTP_ERROR(ECONNABORTED));
4406 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4407 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4408 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4411 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4416 if (sctp_test_T_bit(abort))
4417 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4419 abort->skb->sk = ep->base.sk;
4421 sctp_packet_append_chunk(packet, abort);
4423 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4424 SCTP_PACKET(packet));
4426 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4429 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4432 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4433 return SCTP_DISPOSITION_ABORT;
4436 sctp_chunk_free(abort);
4438 return SCTP_DISPOSITION_NOMEM;
4442 * Handle a protocol violation when the chunk length is invalid.
4443 * "Invalid" length is identified as smaller than the minimal length a
4444 * given chunk can be. For example, a SACK chunk has invalid length
4445 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4447 * We inform the other end by sending an ABORT with a Protocol Violation
4450 * Section: Not specified
4451 * Verification Tag: Nothing to do
4453 * (endpoint, asoc, chunk)
4456 * (reply_msg, msg_up, counters)
4458 * Generate an ABORT chunk and terminate the association.
4460 static sctp_disposition_t sctp_sf_violation_chunklen(
4462 const struct sctp_endpoint *ep,
4463 const struct sctp_association *asoc,
4464 const sctp_subtype_t type,
4466 sctp_cmd_seq_t *commands)
4468 static const char err_str[] = "The following chunk had invalid length:";
4470 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4475 * Handle a protocol violation when the parameter length is invalid.
4476 * If the length is smaller than the minimum length of a given parameter,
4477 * or accumulated length in multi parameters exceeds the end of the chunk,
4478 * the length is considered as invalid.
4480 static sctp_disposition_t sctp_sf_violation_paramlen(
4482 const struct sctp_endpoint *ep,
4483 const struct sctp_association *asoc,
4484 const sctp_subtype_t type,
4485 void *arg, void *ext,
4486 sctp_cmd_seq_t *commands)
4488 struct sctp_chunk *chunk = arg;
4489 struct sctp_paramhdr *param = ext;
4490 struct sctp_chunk *abort = NULL;
4492 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4495 /* Make the abort chunk. */
4496 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4500 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4501 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4503 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4504 SCTP_ERROR(ECONNABORTED));
4505 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4506 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4507 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4508 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4511 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4512 return SCTP_DISPOSITION_ABORT;
4514 return SCTP_DISPOSITION_NOMEM;
4517 /* Handle a protocol violation when the peer trying to advance the
4518 * cumulative tsn ack to a point beyond the max tsn currently sent.
4520 * We inform the other end by sending an ABORT with a Protocol Violation
4523 static sctp_disposition_t sctp_sf_violation_ctsn(
4525 const struct sctp_endpoint *ep,
4526 const struct sctp_association *asoc,
4527 const sctp_subtype_t type,
4529 sctp_cmd_seq_t *commands)
4531 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4533 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4537 /* Handle protocol violation of an invalid chunk bundling. For example,
4538 * when we have an association and we receive bundled INIT-ACK, or
4539 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4540 * statement from the specs. Additionally, there might be an attacker
4541 * on the path and we may not want to continue this communication.
4543 static sctp_disposition_t sctp_sf_violation_chunk(
4545 const struct sctp_endpoint *ep,
4546 const struct sctp_association *asoc,
4547 const sctp_subtype_t type,
4549 sctp_cmd_seq_t *commands)
4551 static const char err_str[] = "The following chunk violates protocol:";
4554 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
4556 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4559 /***************************************************************************
4560 * These are the state functions for handling primitive (Section 10) events.
4561 ***************************************************************************/
4563 * sctp_sf_do_prm_asoc
4565 * Section: 10.1 ULP-to-SCTP
4568 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4569 * outbound stream count)
4570 * -> association id [,destination transport addr list] [,outbound stream
4573 * This primitive allows the upper layer to initiate an association to a
4574 * specific peer endpoint.
4576 * The peer endpoint shall be specified by one of the transport addresses
4577 * which defines the endpoint (see Section 1.4). If the local SCTP
4578 * instance has not been initialized, the ASSOCIATE is considered an
4580 * [This is not relevant for the kernel implementation since we do all
4581 * initialization at boot time. It we hadn't initialized we wouldn't
4582 * get anywhere near this code.]
4584 * An association id, which is a local handle to the SCTP association,
4585 * will be returned on successful establishment of the association. If
4586 * SCTP is not able to open an SCTP association with the peer endpoint,
4587 * an error is returned.
4588 * [In the kernel implementation, the struct sctp_association needs to
4589 * be created BEFORE causing this primitive to run.]
4591 * Other association parameters may be returned, including the
4592 * complete destination transport addresses of the peer as well as the
4593 * outbound stream count of the local endpoint. One of the transport
4594 * address from the returned destination addresses will be selected by
4595 * the local endpoint as default primary path for sending SCTP packets
4596 * to this peer. The returned "destination transport addr list" can
4597 * be used by the ULP to change the default primary path or to force
4598 * sending a packet to a specific transport address. [All of this
4599 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4602 * Mandatory attributes:
4604 * o local SCTP instance name - obtained from the INITIALIZE operation.
4605 * [This is the argument asoc.]
4606 * o destination transport addr - specified as one of the transport
4607 * addresses of the peer endpoint with which the association is to be
4609 * [This is asoc->peer.active_path.]
4610 * o outbound stream count - the number of outbound streams the ULP
4611 * would like to open towards this peer endpoint.
4612 * [BUG: This is not currently implemented.]
4613 * Optional attributes:
4617 * The return value is a disposition.
4619 sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4620 const struct sctp_endpoint *ep,
4621 const struct sctp_association *asoc,
4622 const sctp_subtype_t type,
4624 sctp_cmd_seq_t *commands)
4626 struct sctp_chunk *repl;
4627 struct sctp_association *my_asoc;
4629 /* The comment below says that we enter COOKIE-WAIT AFTER
4630 * sending the INIT, but that doesn't actually work in our
4633 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4634 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4636 /* RFC 2960 5.1 Normal Establishment of an Association
4638 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4639 * must provide its Verification Tag (Tag_A) in the Initiate
4640 * Tag field. Tag_A SHOULD be a random number in the range of
4641 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4644 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4648 /* Choose transport for INIT. */
4649 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4652 /* Cast away the const modifier, as we want to just
4653 * rerun it through as a sideffect.
4655 my_asoc = (struct sctp_association *)asoc;
4656 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4658 /* After sending the INIT, "A" starts the T1-init timer and
4659 * enters the COOKIE-WAIT state.
4661 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4662 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4663 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4664 return SCTP_DISPOSITION_CONSUME;
4667 return SCTP_DISPOSITION_NOMEM;
4671 * Process the SEND primitive.
4673 * Section: 10.1 ULP-to-SCTP
4676 * Format: SEND(association id, buffer address, byte count [,context]
4677 * [,stream id] [,life time] [,destination transport address]
4678 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4681 * This is the main method to send user data via SCTP.
4683 * Mandatory attributes:
4685 * o association id - local handle to the SCTP association
4687 * o buffer address - the location where the user message to be
4688 * transmitted is stored;
4690 * o byte count - The size of the user data in number of bytes;
4692 * Optional attributes:
4694 * o context - an optional 32 bit integer that will be carried in the
4695 * sending failure notification to the ULP if the transportation of
4696 * this User Message fails.
4698 * o stream id - to indicate which stream to send the data on. If not
4699 * specified, stream 0 will be used.
4701 * o life time - specifies the life time of the user data. The user data
4702 * will not be sent by SCTP after the life time expires. This
4703 * parameter can be used to avoid efforts to transmit stale
4704 * user messages. SCTP notifies the ULP if the data cannot be
4705 * initiated to transport (i.e. sent to the destination via SCTP's
4706 * send primitive) within the life time variable. However, the
4707 * user data will be transmitted if SCTP has attempted to transmit a
4708 * chunk before the life time expired.
4710 * o destination transport address - specified as one of the destination
4711 * transport addresses of the peer endpoint to which this packet
4712 * should be sent. Whenever possible, SCTP should use this destination
4713 * transport address for sending the packets, instead of the current
4716 * o unorder flag - this flag, if present, indicates that the user
4717 * would like the data delivered in an unordered fashion to the peer
4718 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4721 * o no-bundle flag - instructs SCTP not to bundle this user data with
4722 * other outbound DATA chunks. SCTP MAY still bundle even when
4723 * this flag is present, when faced with network congestion.
4725 * o payload protocol-id - A 32 bit unsigned integer that is to be
4726 * passed to the peer indicating the type of payload protocol data
4727 * being transmitted. This value is passed as opaque data by SCTP.
4729 * The return value is the disposition.
4731 sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4732 const struct sctp_endpoint *ep,
4733 const struct sctp_association *asoc,
4734 const sctp_subtype_t type,
4736 sctp_cmd_seq_t *commands)
4738 struct sctp_datamsg *msg = arg;
4740 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4741 return SCTP_DISPOSITION_CONSUME;
4745 * Process the SHUTDOWN primitive.
4750 * Format: SHUTDOWN(association id)
4753 * Gracefully closes an association. Any locally queued user data
4754 * will be delivered to the peer. The association will be terminated only
4755 * after the peer acknowledges all the SCTP packets sent. A success code
4756 * will be returned on successful termination of the association. If
4757 * attempting to terminate the association results in a failure, an error
4758 * code shall be returned.
4760 * Mandatory attributes:
4762 * o association id - local handle to the SCTP association
4764 * Optional attributes:
4768 * The return value is the disposition.
4770 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4772 const struct sctp_endpoint *ep,
4773 const struct sctp_association *asoc,
4774 const sctp_subtype_t type,
4776 sctp_cmd_seq_t *commands)
4780 /* From 9.2 Shutdown of an Association
4781 * Upon receipt of the SHUTDOWN primitive from its upper
4782 * layer, the endpoint enters SHUTDOWN-PENDING state and
4783 * remains there until all outstanding data has been
4784 * acknowledged by its peer. The endpoint accepts no new data
4785 * from its upper layer, but retransmits data to the far end
4786 * if necessary to fill gaps.
4788 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4789 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4791 disposition = SCTP_DISPOSITION_CONSUME;
4792 if (sctp_outq_is_empty(&asoc->outqueue)) {
4793 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
4800 * Process the ABORT primitive.
4805 * Format: Abort(association id [, cause code])
4808 * Ungracefully closes an association. Any locally queued user data
4809 * will be discarded and an ABORT chunk is sent to the peer. A success code
4810 * will be returned on successful abortion of the association. If
4811 * attempting to abort the association results in a failure, an error
4812 * code shall be returned.
4814 * Mandatory attributes:
4816 * o association id - local handle to the SCTP association
4818 * Optional attributes:
4820 * o cause code - reason of the abort to be passed to the peer
4824 * The return value is the disposition.
4826 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4828 const struct sctp_endpoint *ep,
4829 const struct sctp_association *asoc,
4830 const sctp_subtype_t type,
4832 sctp_cmd_seq_t *commands)
4834 /* From 9.1 Abort of an Association
4835 * Upon receipt of the ABORT primitive from its upper
4836 * layer, the endpoint enters CLOSED state and
4837 * discard all outstanding data has been
4838 * acknowledged by its peer. The endpoint accepts no new data
4839 * from its upper layer, but retransmits data to the far end
4840 * if necessary to fill gaps.
4842 struct sctp_chunk *abort = arg;
4843 sctp_disposition_t retval;
4845 retval = SCTP_DISPOSITION_CONSUME;
4847 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4849 /* Even if we can't send the ABORT due to low memory delete the
4850 * TCB. This is a departure from our typical NOMEM handling.
4853 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4854 SCTP_ERROR(ECONNABORTED));
4855 /* Delete the established association. */
4856 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4857 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4859 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4860 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4865 /* We tried an illegal operation on an association which is closed. */
4866 sctp_disposition_t sctp_sf_error_closed(struct net *net,
4867 const struct sctp_endpoint *ep,
4868 const struct sctp_association *asoc,
4869 const sctp_subtype_t type,
4871 sctp_cmd_seq_t *commands)
4873 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4874 return SCTP_DISPOSITION_CONSUME;
4877 /* We tried an illegal operation on an association which is shutting
4880 sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4881 const struct sctp_endpoint *ep,
4882 const struct sctp_association *asoc,
4883 const sctp_subtype_t type,
4885 sctp_cmd_seq_t *commands)
4887 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4888 SCTP_ERROR(-ESHUTDOWN));
4889 return SCTP_DISPOSITION_CONSUME;
4893 * sctp_cookie_wait_prm_shutdown
4895 * Section: 4 Note: 2
4900 * The RFC does not explicitly address this issue, but is the route through the
4901 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4906 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4908 const struct sctp_endpoint *ep,
4909 const struct sctp_association *asoc,
4910 const sctp_subtype_t type,
4912 sctp_cmd_seq_t *commands)
4914 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4915 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4917 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4918 SCTP_STATE(SCTP_STATE_CLOSED));
4920 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
4922 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4924 return SCTP_DISPOSITION_DELETE_TCB;
4928 * sctp_cookie_echoed_prm_shutdown
4930 * Section: 4 Note: 2
4935 * The RFC does not explcitly address this issue, but is the route through the
4936 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4941 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4943 const struct sctp_endpoint *ep,
4944 const struct sctp_association *asoc,
4945 const sctp_subtype_t type,
4946 void *arg, sctp_cmd_seq_t *commands)
4948 /* There is a single T1 timer, so we should be able to use
4949 * common function with the COOKIE-WAIT state.
4951 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
4955 * sctp_sf_cookie_wait_prm_abort
4957 * Section: 4 Note: 2
4962 * The RFC does not explicitly address this issue, but is the route through the
4963 * state table when someone issues an abort while in COOKIE_WAIT state.
4968 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4970 const struct sctp_endpoint *ep,
4971 const struct sctp_association *asoc,
4972 const sctp_subtype_t type,
4974 sctp_cmd_seq_t *commands)
4976 struct sctp_chunk *abort = arg;
4977 sctp_disposition_t retval;
4979 /* Stop T1-init timer */
4980 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4981 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4982 retval = SCTP_DISPOSITION_CONSUME;
4984 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4986 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4987 SCTP_STATE(SCTP_STATE_CLOSED));
4989 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4991 /* Even if we can't send the ABORT due to low memory delete the
4992 * TCB. This is a departure from our typical NOMEM handling.
4995 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4996 SCTP_ERROR(ECONNREFUSED));
4997 /* Delete the established association. */
4998 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4999 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5005 * sctp_sf_cookie_echoed_prm_abort
5007 * Section: 4 Note: 3
5012 * The RFC does not explcitly address this issue, but is the route through the
5013 * state table when someone issues an abort while in COOKIE_ECHOED state.
5018 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
5020 const struct sctp_endpoint *ep,
5021 const struct sctp_association *asoc,
5022 const sctp_subtype_t type,
5024 sctp_cmd_seq_t *commands)
5026 /* There is a single T1 timer, so we should be able to use
5027 * common function with the COOKIE-WAIT state.
5029 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5033 * sctp_sf_shutdown_pending_prm_abort
5038 * The RFC does not explicitly address this issue, but is the route through the
5039 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5044 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
5046 const struct sctp_endpoint *ep,
5047 const struct sctp_association *asoc,
5048 const sctp_subtype_t type,
5050 sctp_cmd_seq_t *commands)
5052 /* Stop the T5-shutdown guard timer. */
5053 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5054 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5056 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5060 * sctp_sf_shutdown_sent_prm_abort
5065 * The RFC does not explicitly address this issue, but is the route through the
5066 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5071 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
5073 const struct sctp_endpoint *ep,
5074 const struct sctp_association *asoc,
5075 const sctp_subtype_t type,
5077 sctp_cmd_seq_t *commands)
5079 /* Stop the T2-shutdown timer. */
5080 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5081 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5083 /* Stop the T5-shutdown guard timer. */
5084 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5085 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5087 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5091 * sctp_sf_cookie_echoed_prm_abort
5096 * The RFC does not explcitly address this issue, but is the route through the
5097 * state table when someone issues an abort while in COOKIE_ECHOED state.
5102 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
5104 const struct sctp_endpoint *ep,
5105 const struct sctp_association *asoc,
5106 const sctp_subtype_t type,
5108 sctp_cmd_seq_t *commands)
5110 /* The same T2 timer, so we should be able to use
5111 * common function with the SHUTDOWN-SENT state.
5113 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5117 * Process the REQUESTHEARTBEAT primitive
5120 * J) Request Heartbeat
5122 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5126 * Instructs the local endpoint to perform a HeartBeat on the specified
5127 * destination transport address of the given association. The returned
5128 * result should indicate whether the transmission of the HEARTBEAT
5129 * chunk to the destination address is successful.
5131 * Mandatory attributes:
5133 * o association id - local handle to the SCTP association
5135 * o destination transport address - the transport address of the
5136 * association on which a heartbeat should be issued.
5138 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5140 const struct sctp_endpoint *ep,
5141 const struct sctp_association *asoc,
5142 const sctp_subtype_t type,
5144 sctp_cmd_seq_t *commands)
5146 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5147 (struct sctp_transport *)arg, commands))
5148 return SCTP_DISPOSITION_NOMEM;
5151 * RFC 2960 (bis), section 8.3
5153 * D) Request an on-demand HEARTBEAT on a specific destination
5154 * transport address of a given association.
5156 * The endpoint should increment the respective error counter of
5157 * the destination transport address each time a HEARTBEAT is sent
5158 * to that address and not acknowledged within one RTO.
5161 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5162 SCTP_TRANSPORT(arg));
5163 return SCTP_DISPOSITION_CONSUME;
5167 * ADDIP Section 4.1 ASCONF Chunk Procedures
5168 * When an endpoint has an ASCONF signaled change to be sent to the
5169 * remote endpoint it should do A1 to A9
5171 sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5172 const struct sctp_endpoint *ep,
5173 const struct sctp_association *asoc,
5174 const sctp_subtype_t type,
5176 sctp_cmd_seq_t *commands)
5178 struct sctp_chunk *chunk = arg;
5180 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5181 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5182 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5183 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5184 return SCTP_DISPOSITION_CONSUME;
5188 * Ignore the primitive event
5190 * The return value is the disposition of the primitive.
5192 sctp_disposition_t sctp_sf_ignore_primitive(
5194 const struct sctp_endpoint *ep,
5195 const struct sctp_association *asoc,
5196 const sctp_subtype_t type,
5198 sctp_cmd_seq_t *commands)
5200 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5203 return SCTP_DISPOSITION_DISCARD;
5206 /***************************************************************************
5207 * These are the state functions for the OTHER events.
5208 ***************************************************************************/
5211 * When the SCTP stack has no more user data to send or retransmit, this
5212 * notification is given to the user. Also, at the time when a user app
5213 * subscribes to this event, if there is no data to be sent or
5214 * retransmit, the stack will immediately send up this notification.
5216 sctp_disposition_t sctp_sf_do_no_pending_tsn(
5218 const struct sctp_endpoint *ep,
5219 const struct sctp_association *asoc,
5220 const sctp_subtype_t type,
5222 sctp_cmd_seq_t *commands)
5224 struct sctp_ulpevent *event;
5226 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5228 return SCTP_DISPOSITION_NOMEM;
5230 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5232 return SCTP_DISPOSITION_CONSUME;
5236 * Start the shutdown negotiation.
5239 * Once all its outstanding data has been acknowledged, the endpoint
5240 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5241 * TSN Ack field the last sequential TSN it has received from the peer.
5242 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5243 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5244 * with the updated last sequential TSN received from its peer.
5246 * The return value is the disposition.
5248 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5250 const struct sctp_endpoint *ep,
5251 const struct sctp_association *asoc,
5252 const sctp_subtype_t type,
5254 sctp_cmd_seq_t *commands)
5256 struct sctp_chunk *reply;
5258 /* Once all its outstanding data has been acknowledged, the
5259 * endpoint shall send a SHUTDOWN chunk to its peer including
5260 * in the Cumulative TSN Ack field the last sequential TSN it
5261 * has received from the peer.
5263 reply = sctp_make_shutdown(asoc, NULL);
5267 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5268 * T2-shutdown timer.
5270 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5272 /* It shall then start the T2-shutdown timer */
5273 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5274 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5276 /* RFC 4960 Section 9.2
5277 * The sender of the SHUTDOWN MAY also start an overall guard timer
5278 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5280 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5281 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5283 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5284 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5285 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5287 /* and enter the SHUTDOWN-SENT state. */
5288 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5289 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5291 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5293 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5296 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5298 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5300 return SCTP_DISPOSITION_CONSUME;
5303 return SCTP_DISPOSITION_NOMEM;
5307 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5311 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5312 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5313 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5314 * endpoint must re-send the SHUTDOWN ACK.
5316 * The return value is the disposition.
5318 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5320 const struct sctp_endpoint *ep,
5321 const struct sctp_association *asoc,
5322 const sctp_subtype_t type,
5324 sctp_cmd_seq_t *commands)
5326 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5327 struct sctp_chunk *reply;
5329 /* There are 2 ways of getting here:
5330 * 1) called in response to a SHUTDOWN chunk
5331 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5333 * For the case (2), the arg parameter is set to NULL. We need
5334 * to check that we have a chunk before accessing it's fields.
5337 if (!sctp_vtag_verify(chunk, asoc))
5338 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
5340 /* Make sure that the SHUTDOWN chunk has a valid length. */
5341 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5342 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
5346 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5347 * shall send a SHUTDOWN ACK ...
5349 reply = sctp_make_shutdown_ack(asoc, chunk);
5353 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5354 * the T2-shutdown timer.
5356 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5358 /* and start/restart a T2-shutdown timer of its own, */
5359 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5360 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5362 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5364 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5366 /* Enter the SHUTDOWN-ACK-SENT state. */
5367 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5368 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5370 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5372 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5375 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5377 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5379 return SCTP_DISPOSITION_CONSUME;
5382 return SCTP_DISPOSITION_NOMEM;
5386 * Ignore the event defined as other
5388 * The return value is the disposition of the event.
5390 sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5391 const struct sctp_endpoint *ep,
5392 const struct sctp_association *asoc,
5393 const sctp_subtype_t type,
5395 sctp_cmd_seq_t *commands)
5397 pr_debug("%s: the event other type:%d is ignored\n",
5398 __func__, type.other);
5400 return SCTP_DISPOSITION_DISCARD;
5403 /************************************************************
5404 * These are the state functions for handling timeout events.
5405 ************************************************************/
5410 * Section: 6.3.3 Handle T3-rtx Expiration
5412 * Whenever the retransmission timer T3-rtx expires for a destination
5413 * address, do the following:
5416 * The return value is the disposition of the chunk.
5418 sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5419 const struct sctp_endpoint *ep,
5420 const struct sctp_association *asoc,
5421 const sctp_subtype_t type,
5423 sctp_cmd_seq_t *commands)
5425 struct sctp_transport *transport = arg;
5427 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5429 if (asoc->overall_error_count >= asoc->max_retrans) {
5430 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5432 * We are here likely because the receiver had its rwnd
5433 * closed for a while and we have not been able to
5434 * transmit the locally queued data within the maximum
5435 * retransmission attempts limit. Start the T5
5436 * shutdown guard timer to give the receiver one last
5437 * chance and some additional time to recover before
5440 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5441 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5443 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5444 SCTP_ERROR(ETIMEDOUT));
5445 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5446 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5447 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5448 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5449 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5450 return SCTP_DISPOSITION_DELETE_TCB;
5454 /* E1) For the destination address for which the timer
5455 * expires, adjust its ssthresh with rules defined in Section
5456 * 7.2.3 and set the cwnd <- MTU.
5459 /* E2) For the destination address for which the timer
5460 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5461 * maximum value discussed in rule C7 above (RTO.max) may be
5462 * used to provide an upper bound to this doubling operation.
5465 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5466 * outstanding DATA chunks for the address for which the
5467 * T3-rtx has expired will fit into a single packet, subject
5468 * to the MTU constraint for the path corresponding to the
5469 * destination transport address to which the retransmission
5470 * is being sent (this may be different from the address for
5471 * which the timer expires [see Section 6.4]). Call this
5472 * value K. Bundle and retransmit those K DATA chunks in a
5473 * single packet to the destination endpoint.
5475 * Note: Any DATA chunks that were sent to the address for
5476 * which the T3-rtx timer expired but did not fit in one MTU
5477 * (rule E3 above), should be marked for retransmission and
5478 * sent as soon as cwnd allows (normally when a SACK arrives).
5481 /* Do some failure management (Section 8.2). */
5482 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5484 /* NB: Rules E4 and F1 are implicit in R1. */
5485 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5487 return SCTP_DISPOSITION_CONSUME;
5491 * Generate delayed SACK on timeout
5493 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5495 * The guidelines on delayed acknowledgement algorithm specified in
5496 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5497 * acknowledgement SHOULD be generated for at least every second packet
5498 * (not every second DATA chunk) received, and SHOULD be generated
5499 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5500 * some situations it may be beneficial for an SCTP transmitter to be
5501 * more conservative than the algorithms detailed in this document
5502 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5503 * the following algorithms allow.
5505 sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5506 const struct sctp_endpoint *ep,
5507 const struct sctp_association *asoc,
5508 const sctp_subtype_t type,
5510 sctp_cmd_seq_t *commands)
5512 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5513 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5514 return SCTP_DISPOSITION_CONSUME;
5518 * sctp_sf_t1_init_timer_expire
5520 * Section: 4 Note: 2
5525 * RFC 2960 Section 4 Notes
5526 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5527 * and re-start the T1-init timer without changing state. This MUST
5528 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5529 * endpoint MUST abort the initialization process and report the
5530 * error to SCTP user.
5536 sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5537 const struct sctp_endpoint *ep,
5538 const struct sctp_association *asoc,
5539 const sctp_subtype_t type,
5541 sctp_cmd_seq_t *commands)
5543 struct sctp_chunk *repl = NULL;
5544 struct sctp_bind_addr *bp;
5545 int attempts = asoc->init_err_counter + 1;
5547 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5549 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5551 if (attempts <= asoc->max_init_attempts) {
5552 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5553 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5555 return SCTP_DISPOSITION_NOMEM;
5557 /* Choose transport for INIT. */
5558 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5561 /* Issue a sideeffect to do the needed accounting. */
5562 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5563 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5565 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5567 pr_debug("%s: giving up on INIT, attempts:%d "
5568 "max_init_attempts:%d\n", __func__, attempts,
5569 asoc->max_init_attempts);
5571 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5572 SCTP_ERROR(ETIMEDOUT));
5573 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5574 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5575 return SCTP_DISPOSITION_DELETE_TCB;
5578 return SCTP_DISPOSITION_CONSUME;
5582 * sctp_sf_t1_cookie_timer_expire
5584 * Section: 4 Note: 2
5589 * RFC 2960 Section 4 Notes
5590 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5591 * COOKIE ECHO and re-start the T1-cookie timer without changing
5592 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5593 * After that, the endpoint MUST abort the initialization process and
5594 * report the error to SCTP user.
5600 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5601 const struct sctp_endpoint *ep,
5602 const struct sctp_association *asoc,
5603 const sctp_subtype_t type,
5605 sctp_cmd_seq_t *commands)
5607 struct sctp_chunk *repl = NULL;
5608 int attempts = asoc->init_err_counter + 1;
5610 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5612 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5614 if (attempts <= asoc->max_init_attempts) {
5615 repl = sctp_make_cookie_echo(asoc, NULL);
5617 return SCTP_DISPOSITION_NOMEM;
5619 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5621 /* Issue a sideeffect to do the needed accounting. */
5622 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5623 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5625 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5627 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5628 SCTP_ERROR(ETIMEDOUT));
5629 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5630 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5631 return SCTP_DISPOSITION_DELETE_TCB;
5634 return SCTP_DISPOSITION_CONSUME;
5637 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5638 * with the updated last sequential TSN received from its peer.
5640 * An endpoint should limit the number of retransmissions of the
5641 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5642 * If this threshold is exceeded the endpoint should destroy the TCB and
5643 * MUST report the peer endpoint unreachable to the upper layer (and
5644 * thus the association enters the CLOSED state). The reception of any
5645 * packet from its peer (i.e. as the peer sends all of its queued DATA
5646 * chunks) should clear the endpoint's retransmission count and restart
5647 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5648 * all of its queued DATA chunks that have not yet been sent.
5650 sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5651 const struct sctp_endpoint *ep,
5652 const struct sctp_association *asoc,
5653 const sctp_subtype_t type,
5655 sctp_cmd_seq_t *commands)
5657 struct sctp_chunk *reply = NULL;
5659 pr_debug("%s: timer T2 expired\n", __func__);
5661 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5663 ((struct sctp_association *)asoc)->shutdown_retries++;
5665 if (asoc->overall_error_count >= asoc->max_retrans) {
5666 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5667 SCTP_ERROR(ETIMEDOUT));
5668 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5669 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5670 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5671 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5672 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5673 return SCTP_DISPOSITION_DELETE_TCB;
5676 switch (asoc->state) {
5677 case SCTP_STATE_SHUTDOWN_SENT:
5678 reply = sctp_make_shutdown(asoc, NULL);
5681 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5682 reply = sctp_make_shutdown_ack(asoc, NULL);
5693 /* Do some failure management (Section 8.2).
5694 * If we remove the transport an SHUTDOWN was last sent to, don't
5695 * do failure management.
5697 if (asoc->shutdown_last_sent_to)
5698 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5699 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5701 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5702 * the T2-shutdown timer.
5704 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5706 /* Restart the T2-shutdown timer. */
5707 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5708 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5709 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5710 return SCTP_DISPOSITION_CONSUME;
5713 return SCTP_DISPOSITION_NOMEM;
5717 * ADDIP Section 4.1 ASCONF CHunk Procedures
5718 * If the T4 RTO timer expires the endpoint should do B1 to B5
5720 sctp_disposition_t sctp_sf_t4_timer_expire(
5722 const struct sctp_endpoint *ep,
5723 const struct sctp_association *asoc,
5724 const sctp_subtype_t type,
5726 sctp_cmd_seq_t *commands)
5728 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5729 struct sctp_transport *transport = chunk->transport;
5731 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
5733 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5734 * detection on the appropriate destination address as defined in
5735 * RFC2960 [5] section 8.1 and 8.2.
5738 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5739 SCTP_TRANSPORT(transport));
5741 /* Reconfig T4 timer and transport. */
5742 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5744 /* ADDIP 4.1 B2) Increment the association error counters and perform
5745 * endpoint failure detection on the association as defined in
5746 * RFC2960 [5] section 8.1 and 8.2.
5747 * association error counter is incremented in SCTP_CMD_STRIKE.
5749 if (asoc->overall_error_count >= asoc->max_retrans) {
5750 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5751 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5752 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5753 SCTP_ERROR(ETIMEDOUT));
5754 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5755 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5756 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5757 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5758 return SCTP_DISPOSITION_ABORT;
5761 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5762 * the ASCONF chunk was sent by doubling the RTO timer value.
5763 * This is done in SCTP_CMD_STRIKE.
5766 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5767 * choose an alternate destination address (please refer to RFC2960
5768 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5769 * chunk, it MUST be the same (including its serial number) as the last
5772 sctp_chunk_hold(asoc->addip_last_asconf);
5773 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5774 SCTP_CHUNK(asoc->addip_last_asconf));
5776 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5777 * destination is selected, then the RTO used will be that of the new
5778 * destination address.
5780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5781 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5783 return SCTP_DISPOSITION_CONSUME;
5786 /* sctpimpguide-05 Section 2.12.2
5787 * The sender of the SHUTDOWN MAY also start an overall guard timer
5788 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5789 * At the expiration of this timer the sender SHOULD abort the association
5790 * by sending an ABORT chunk.
5792 sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5793 const struct sctp_endpoint *ep,
5794 const struct sctp_association *asoc,
5795 const sctp_subtype_t type,
5797 sctp_cmd_seq_t *commands)
5799 struct sctp_chunk *reply = NULL;
5801 pr_debug("%s: timer T5 expired\n", __func__);
5803 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5805 reply = sctp_make_abort(asoc, NULL, 0);
5809 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5810 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5811 SCTP_ERROR(ETIMEDOUT));
5812 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5813 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5815 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5816 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5818 return SCTP_DISPOSITION_DELETE_TCB;
5820 return SCTP_DISPOSITION_NOMEM;
5823 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5824 * the association is automatically closed by starting the shutdown process.
5825 * The work that needs to be done is same as when SHUTDOWN is initiated by
5826 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5828 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5830 const struct sctp_endpoint *ep,
5831 const struct sctp_association *asoc,
5832 const sctp_subtype_t type,
5834 sctp_cmd_seq_t *commands)
5838 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
5840 /* From 9.2 Shutdown of an Association
5841 * Upon receipt of the SHUTDOWN primitive from its upper
5842 * layer, the endpoint enters SHUTDOWN-PENDING state and
5843 * remains there until all outstanding data has been
5844 * acknowledged by its peer. The endpoint accepts no new data
5845 * from its upper layer, but retransmits data to the far end
5846 * if necessary to fill gaps.
5848 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5849 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5851 disposition = SCTP_DISPOSITION_CONSUME;
5852 if (sctp_outq_is_empty(&asoc->outqueue)) {
5853 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
5859 /*****************************************************************************
5860 * These are sa state functions which could apply to all types of events.
5861 ****************************************************************************/
5864 * This table entry is not implemented.
5867 * (endpoint, asoc, chunk)
5869 * The return value is the disposition of the chunk.
5871 sctp_disposition_t sctp_sf_not_impl(struct net *net,
5872 const struct sctp_endpoint *ep,
5873 const struct sctp_association *asoc,
5874 const sctp_subtype_t type,
5876 sctp_cmd_seq_t *commands)
5878 return SCTP_DISPOSITION_NOT_IMPL;
5882 * This table entry represents a bug.
5885 * (endpoint, asoc, chunk)
5887 * The return value is the disposition of the chunk.
5889 sctp_disposition_t sctp_sf_bug(struct net *net,
5890 const struct sctp_endpoint *ep,
5891 const struct sctp_association *asoc,
5892 const sctp_subtype_t type,
5894 sctp_cmd_seq_t *commands)
5896 return SCTP_DISPOSITION_BUG;
5900 * This table entry represents the firing of a timer in the wrong state.
5901 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5902 * when the association is in the wrong state. This event should
5903 * be ignored, so as to prevent any rearming of the timer.
5906 * (endpoint, asoc, chunk)
5908 * The return value is the disposition of the chunk.
5910 sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5911 const struct sctp_endpoint *ep,
5912 const struct sctp_association *asoc,
5913 const sctp_subtype_t type,
5915 sctp_cmd_seq_t *commands)
5917 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
5919 return SCTP_DISPOSITION_CONSUME;
5922 /********************************************************************
5923 * 2nd Level Abstractions
5924 ********************************************************************/
5926 /* Pull the SACK chunk based on the SACK header. */
5927 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5929 struct sctp_sackhdr *sack;
5934 /* Protect ourselves from reading too far into
5935 * the skb from a bogus sender.
5937 sack = (struct sctp_sackhdr *) chunk->skb->data;
5939 num_blocks = ntohs(sack->num_gap_ack_blocks);
5940 num_dup_tsns = ntohs(sack->num_dup_tsns);
5941 len = sizeof(struct sctp_sackhdr);
5942 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5943 if (len > chunk->skb->len)
5946 skb_pull(chunk->skb, len);
5951 /* Create an ABORT packet to be sent as a response, with the specified
5954 static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
5955 const struct sctp_endpoint *ep,
5956 const struct sctp_association *asoc,
5957 struct sctp_chunk *chunk,
5958 const void *payload,
5961 struct sctp_packet *packet;
5962 struct sctp_chunk *abort;
5964 packet = sctp_ootb_pkt_new(net, asoc, chunk);
5968 * The T bit will be set if the asoc is NULL.
5970 abort = sctp_make_abort(asoc, chunk, paylen);
5972 sctp_ootb_pkt_free(packet);
5976 /* Reflect vtag if T-Bit is set */
5977 if (sctp_test_T_bit(abort))
5978 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5980 /* Add specified error causes, i.e., payload, to the
5983 sctp_addto_chunk(abort, paylen, payload);
5985 /* Set the skb to the belonging sock for accounting. */
5986 abort->skb->sk = ep->base.sk;
5988 sctp_packet_append_chunk(packet, abort);
5995 /* Allocate a packet for responding in the OOTB conditions. */
5996 static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5997 const struct sctp_association *asoc,
5998 const struct sctp_chunk *chunk)
6000 struct sctp_packet *packet;
6001 struct sctp_transport *transport;
6006 /* Get the source and destination port from the inbound packet. */
6007 sport = ntohs(chunk->sctp_hdr->dest);
6008 dport = ntohs(chunk->sctp_hdr->source);
6010 /* The V-tag is going to be the same as the inbound packet if no
6011 * association exists, otherwise, use the peer's vtag.
6014 /* Special case the INIT-ACK as there is no peer's vtag
6017 switch (chunk->chunk_hdr->type) {
6018 case SCTP_CID_INIT_ACK:
6020 sctp_initack_chunk_t *initack;
6022 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6023 vtag = ntohl(initack->init_hdr.init_tag);
6027 vtag = asoc->peer.i.init_tag;
6031 /* Special case the INIT and stale COOKIE_ECHO as there is no
6034 switch (chunk->chunk_hdr->type) {
6037 sctp_init_chunk_t *init;
6039 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6040 vtag = ntohl(init->init_hdr.init_tag);
6044 vtag = ntohl(chunk->sctp_hdr->vtag);
6049 /* Make a transport for the bucket, Eliza... */
6050 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6054 /* Cache a route for the transport with the chunk's destination as
6055 * the source address.
6057 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6058 sctp_sk(net->sctp.ctl_sock));
6060 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
6061 packet = sctp_packet_config(packet, vtag, 0);
6069 /* Free the packet allocated earlier for responding in the OOTB condition. */
6070 void sctp_ootb_pkt_free(struct sctp_packet *packet)
6072 sctp_transport_free(packet->transport);
6075 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6076 static void sctp_send_stale_cookie_err(struct net *net,
6077 const struct sctp_endpoint *ep,
6078 const struct sctp_association *asoc,
6079 const struct sctp_chunk *chunk,
6080 sctp_cmd_seq_t *commands,
6081 struct sctp_chunk *err_chunk)
6083 struct sctp_packet *packet;
6086 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6088 struct sctp_signed_cookie *cookie;
6090 /* Override the OOTB vtag from the cookie. */
6091 cookie = chunk->subh.cookie_hdr;
6092 packet->vtag = cookie->c.peer_vtag;
6094 /* Set the skb to the belonging sock for accounting. */
6095 err_chunk->skb->sk = ep->base.sk;
6096 sctp_packet_append_chunk(packet, err_chunk);
6097 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6098 SCTP_PACKET(packet));
6099 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6101 sctp_chunk_free (err_chunk);
6106 /* Process a data chunk */
6107 static int sctp_eat_data(const struct sctp_association *asoc,
6108 struct sctp_chunk *chunk,
6109 sctp_cmd_seq_t *commands)
6111 sctp_datahdr_t *data_hdr;
6112 struct sctp_chunk *err;
6114 sctp_verb_t deliver;
6117 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6118 struct sock *sk = asoc->base.sk;
6119 struct net *net = sock_net(sk);
6124 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6125 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6127 tsn = ntohl(data_hdr->tsn);
6128 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6130 /* ASSERT: Now skb->data is really the user data. */
6132 /* Process ECN based congestion.
6134 * Since the chunk structure is reused for all chunks within
6135 * a packet, we use ecn_ce_done to track if we've already
6136 * done CE processing for this packet.
6138 * We need to do ECN processing even if we plan to discard the
6142 if (!chunk->ecn_ce_done) {
6144 chunk->ecn_ce_done = 1;
6146 af = sctp_get_af_specific(
6147 ipver2af(ip_hdr(chunk->skb)->version));
6149 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6150 /* Do real work as sideffect. */
6151 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6156 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6158 /* The TSN is too high--silently discard the chunk and
6159 * count on it getting retransmitted later.
6162 chunk->asoc->stats.outofseqtsns++;
6163 return SCTP_IERROR_HIGH_TSN;
6164 } else if (tmp > 0) {
6165 /* This is a duplicate. Record it. */
6166 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6167 return SCTP_IERROR_DUP_TSN;
6170 /* This is a new TSN. */
6172 /* Discard if there is no room in the receive window.
6173 * Actually, allow a little bit of overflow (up to a MTU).
6175 datalen = ntohs(chunk->chunk_hdr->length);
6176 datalen -= sizeof(sctp_data_chunk_t);
6178 deliver = SCTP_CMD_CHUNK_ULP;
6180 /* Think about partial delivery. */
6181 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6183 /* Even if we don't accept this chunk there is
6186 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6189 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6190 * seems a bit troublesome in that frag_point varies based on
6191 * PMTU. In cases, such as loopback, this might be a rather
6194 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6195 (datalen > asoc->rwnd + asoc->frag_point))) {
6197 /* If this is the next TSN, consider reneging to make
6198 * room. Note: Playing nice with a confused sender. A
6199 * malicious sender can still eat up all our buffer
6200 * space and in the future we may want to detect and
6201 * do more drastic reneging.
6203 if (sctp_tsnmap_has_gap(map) &&
6204 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6205 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6206 deliver = SCTP_CMD_RENEGE;
6208 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6209 __func__, tsn, datalen, asoc->rwnd);
6211 return SCTP_IERROR_IGNORE_TSN;
6216 * Also try to renege to limit our memory usage in the event that
6217 * we are under memory pressure
6218 * If we can't renege, don't worry about it, the sk_rmem_schedule
6219 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6220 * memory usage too much
6222 if (*sk->sk_prot_creator->memory_pressure) {
6223 if (sctp_tsnmap_has_gap(map) &&
6224 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6225 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6227 deliver = SCTP_CMD_RENEGE;
6232 * Section 3.3.10.9 No User Data (9)
6236 * No User Data: This error cause is returned to the originator of a
6237 * DATA chunk if a received DATA chunk has no user data.
6239 if (unlikely(0 == datalen)) {
6240 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6242 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6245 /* We are going to ABORT, so we might as well stop
6246 * processing the rest of the chunks in the packet.
6248 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6249 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6250 SCTP_ERROR(ECONNABORTED));
6251 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6252 SCTP_PERR(SCTP_ERROR_NO_DATA));
6253 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6254 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6255 return SCTP_IERROR_NO_DATA;
6258 chunk->data_accepted = 1;
6260 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6261 * if we renege and the chunk arrives again.
6263 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6264 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6266 chunk->asoc->stats.iuodchunks++;
6268 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6270 chunk->asoc->stats.iodchunks++;
6274 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6276 * If an endpoint receive a DATA chunk with an invalid stream
6277 * identifier, it shall acknowledge the reception of the DATA chunk
6278 * following the normal procedure, immediately send an ERROR chunk
6279 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6280 * and discard the DATA chunk.
6282 sid = ntohs(data_hdr->stream);
6283 if (sid >= asoc->c.sinit_max_instreams) {
6284 /* Mark tsn as received even though we drop it */
6285 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6287 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6289 sizeof(data_hdr->stream),
6292 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6294 return SCTP_IERROR_BAD_STREAM;
6297 /* Check to see if the SSN is possible for this TSN.
6298 * The biggest gap we can record is 4K wide. Since SSNs wrap
6299 * at an unsigned short, there is no way that an SSN can
6300 * wrap and for a valid TSN. We can simply check if the current
6301 * SSN is smaller then the next expected one. If it is, it wrapped
6304 ssn = ntohs(data_hdr->ssn);
6305 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6306 return SCTP_IERROR_PROTO_VIOLATION;
6309 /* Send the data up to the user. Note: Schedule the
6310 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6311 * chunk needs the updated rwnd.
6313 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6315 return SCTP_IERROR_NO_ERROR;