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 /* Previously already marked? */
174 if (unlikely(chunk->pdiscard))
176 if (unlikely(chunk_length < required_length))
182 /**********************************************************
183 * These are the state functions for handling chunk events.
184 **********************************************************/
187 * Process the final SHUTDOWN COMPLETE.
189 * Section: 4 (C) (diagram), 9.2
190 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
191 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
192 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
193 * should stop the T2-shutdown timer and remove all knowledge of the
194 * association (and thus the association enters the CLOSED state).
196 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
197 * C) Rules for packet carrying SHUTDOWN COMPLETE:
199 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
200 * if the Verification Tag field of the packet matches its own tag and
201 * the T bit is not set
203 * it is set to its peer's tag and the T bit is set in the Chunk
205 * Otherwise, the receiver MUST silently discard the packet
206 * and take no further action. An endpoint MUST ignore the
207 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
210 * (endpoint, asoc, chunk)
213 * (asoc, reply_msg, msg_up, timers, counters)
215 * The return value is the disposition of the chunk.
217 sctp_disposition_t sctp_sf_do_4_C(struct net *net,
218 const struct sctp_endpoint *ep,
219 const struct sctp_association *asoc,
220 const sctp_subtype_t type,
222 sctp_cmd_seq_t *commands)
224 struct sctp_chunk *chunk = arg;
225 struct sctp_ulpevent *ev;
227 if (!sctp_vtag_verify_either(chunk, asoc))
228 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
230 /* RFC 2960 6.10 Bundling
232 * An endpoint MUST NOT bundle INIT, INIT ACK or
233 * SHUTDOWN COMPLETE with any other chunks.
235 if (!chunk->singleton)
236 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
238 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
239 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
240 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
243 /* RFC 2960 10.2 SCTP-to-ULP
245 * H) SHUTDOWN COMPLETE notification
247 * When SCTP completes the shutdown procedures (section 9.2) this
248 * notification is passed to the upper layer.
250 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
251 0, 0, 0, NULL, GFP_ATOMIC);
253 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
256 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
257 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
258 * not the chunk should be discarded. If the endpoint is in
259 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
260 * T2-shutdown timer and remove all knowledge of the
261 * association (and thus the association enters the CLOSED
264 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
265 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
267 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
268 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
270 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
271 SCTP_STATE(SCTP_STATE_CLOSED));
273 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
274 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
276 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
278 return SCTP_DISPOSITION_DELETE_TCB;
282 * Respond to a normal INIT chunk.
283 * We are the side that is being asked for an association.
285 * Section: 5.1 Normal Establishment of an Association, B
286 * B) "Z" shall respond immediately with an INIT ACK chunk. The
287 * destination IP address of the INIT ACK MUST be set to the source
288 * IP address of the INIT to which this INIT ACK is responding. In
289 * the response, besides filling in other parameters, "Z" must set the
290 * Verification Tag field to Tag_A, and also provide its own
291 * Verification Tag (Tag_Z) in the Initiate Tag field.
293 * Verification Tag: Must be 0.
296 * (endpoint, asoc, chunk)
299 * (asoc, reply_msg, msg_up, timers, counters)
301 * The return value is the disposition of the chunk.
303 sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
304 const struct sctp_endpoint *ep,
305 const struct sctp_association *asoc,
306 const sctp_subtype_t type,
308 sctp_cmd_seq_t *commands)
310 struct sctp_chunk *chunk = arg;
311 struct sctp_chunk *repl;
312 struct sctp_association *new_asoc;
313 struct sctp_chunk *err_chunk;
314 struct sctp_packet *packet;
315 sctp_unrecognized_param_t *unk_param;
319 * An endpoint MUST NOT bundle INIT, INIT ACK or
320 * SHUTDOWN COMPLETE with any other chunks.
323 * Furthermore, we require that the receiver of an INIT chunk MUST
324 * enforce these rules by silently discarding an arriving packet
325 * with an INIT chunk that is bundled with other chunks.
327 if (!chunk->singleton)
328 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
330 /* If the packet is an OOTB packet which is temporarily on the
331 * control endpoint, respond with an ABORT.
333 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
334 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
335 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
338 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
341 if (chunk->sctp_hdr->vtag != 0)
342 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
344 /* Make sure that the INIT chunk has a valid length.
345 * Normally, this would cause an ABORT with a Protocol Violation
346 * error, but since we don't have an association, we'll
347 * just discard the packet.
349 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
350 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
352 /* If the INIT is coming toward a closing socket, we'll send back
353 * and ABORT. Essentially, this catches the race of INIT being
354 * backloged to the socket at the same time as the user isses close().
355 * Since the socket and all its associations are going away, we
356 * can treat this OOTB
358 if (sctp_sstate(ep->base.sk, CLOSING))
359 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
361 /* Verify the INIT chunk before processing it. */
363 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
364 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
366 /* This chunk contains fatal error. It is to be discarded.
367 * Send an ABORT, with causes if there is any.
370 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
371 (__u8 *)(err_chunk->chunk_hdr) +
372 sizeof(sctp_chunkhdr_t),
373 ntohs(err_chunk->chunk_hdr->length) -
374 sizeof(sctp_chunkhdr_t));
376 sctp_chunk_free(err_chunk);
379 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
380 SCTP_PACKET(packet));
381 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
382 return SCTP_DISPOSITION_CONSUME;
384 return SCTP_DISPOSITION_NOMEM;
387 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
392 /* Grab the INIT header. */
393 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
395 /* Tag the variable length parameters. */
396 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
398 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
402 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
403 sctp_scope(sctp_source(chunk)),
407 /* The call, sctp_process_init(), can fail on memory allocation. */
408 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
409 (sctp_init_chunk_t *)chunk->chunk_hdr,
413 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
415 /* If there are errors need to be reported for unknown parameters,
416 * make sure to reserve enough room in the INIT ACK for them.
420 len = ntohs(err_chunk->chunk_hdr->length) -
421 sizeof(sctp_chunkhdr_t);
423 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
427 /* If there are errors need to be reported for unknown parameters,
428 * include them in the outgoing INIT ACK as "Unrecognized parameter"
432 /* Get the "Unrecognized parameter" parameter(s) out of the
433 * ERROR chunk generated by sctp_verify_init(). Since the
434 * error cause code for "unknown parameter" and the
435 * "Unrecognized parameter" type is the same, we can
436 * construct the parameters in INIT ACK by copying the
439 unk_param = (sctp_unrecognized_param_t *)
440 ((__u8 *)(err_chunk->chunk_hdr) +
441 sizeof(sctp_chunkhdr_t));
442 /* Replace the cause code with the "Unrecognized parameter"
445 sctp_addto_chunk(repl, len, unk_param);
446 sctp_chunk_free(err_chunk);
449 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
451 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
454 * Note: After sending out INIT ACK with the State Cookie parameter,
455 * "Z" MUST NOT allocate any resources, nor keep any states for the
456 * new association. Otherwise, "Z" will be vulnerable to resource
459 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
461 return SCTP_DISPOSITION_DELETE_TCB;
464 sctp_association_free(new_asoc);
467 sctp_chunk_free(err_chunk);
468 return SCTP_DISPOSITION_NOMEM;
472 * Respond to a normal INIT ACK chunk.
473 * We are the side that is initiating the association.
475 * Section: 5.1 Normal Establishment of an Association, C
476 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
477 * timer and leave COOKIE-WAIT state. "A" shall then send the State
478 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
479 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
481 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
482 * DATA chunks, but it MUST be the first chunk in the packet and
483 * until the COOKIE ACK is returned the sender MUST NOT send any
484 * other packets to the peer.
486 * Verification Tag: 3.3.3
487 * If the value of the Initiate Tag in a received INIT ACK chunk is
488 * found to be 0, the receiver MUST treat it as an error and close the
489 * association by transmitting an ABORT.
492 * (endpoint, asoc, chunk)
495 * (asoc, reply_msg, msg_up, timers, counters)
497 * The return value is the disposition of the chunk.
499 sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
500 const struct sctp_endpoint *ep,
501 const struct sctp_association *asoc,
502 const sctp_subtype_t type,
504 sctp_cmd_seq_t *commands)
506 struct sctp_chunk *chunk = arg;
507 sctp_init_chunk_t *initchunk;
508 struct sctp_chunk *err_chunk;
509 struct sctp_packet *packet;
511 if (!sctp_vtag_verify(chunk, asoc))
512 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
515 * An endpoint MUST NOT bundle INIT, INIT ACK or
516 * SHUTDOWN COMPLETE with any other chunks.
518 if (!chunk->singleton)
519 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
521 /* Make sure that the INIT-ACK chunk has a valid length */
522 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
523 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
525 /* Grab the INIT header. */
526 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
528 /* Verify the INIT chunk before processing it. */
530 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
531 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
534 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
536 /* This chunk contains fatal error. It is to be discarded.
537 * Send an ABORT, with causes. If there are no causes,
538 * then there wasn't enough memory. Just terminate
542 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
543 (__u8 *)(err_chunk->chunk_hdr) +
544 sizeof(sctp_chunkhdr_t),
545 ntohs(err_chunk->chunk_hdr->length) -
546 sizeof(sctp_chunkhdr_t));
548 sctp_chunk_free(err_chunk);
551 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
552 SCTP_PACKET(packet));
553 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
554 error = SCTP_ERROR_INV_PARAM;
558 /* SCTP-AUTH, Section 6.3:
559 * It should be noted that if the receiver wants to tear
560 * down an association in an authenticated way only, the
561 * handling of malformed packets should not result in
562 * tearing down the association.
564 * This means that if we only want to abort associations
565 * in an authenticated way (i.e AUTH+ABORT), then we
566 * can't destroy this association just because the packet
569 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
570 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
572 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
573 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
574 asoc, chunk->transport);
577 /* Tag the variable length parameters. Note that we never
578 * convert the parameters in an INIT chunk.
580 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
582 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
584 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
585 SCTP_PEER_INIT(initchunk));
587 /* Reset init error count upon receipt of INIT-ACK. */
588 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
590 /* 5.1 C) "A" shall stop the T1-init timer and leave
591 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
592 * timer, and enter the COOKIE-ECHOED state.
594 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
595 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
596 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
597 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
598 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
599 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
601 /* SCTP-AUTH: genereate the assocition shared keys so that
602 * we can potentially signe the COOKIE-ECHO.
604 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
606 /* 5.1 C) "A" shall then send the State Cookie received in the
607 * INIT ACK chunk in a COOKIE ECHO chunk, ...
609 /* If there is any errors to report, send the ERROR chunk generated
610 * for unknown parameters as well.
612 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
613 SCTP_CHUNK(err_chunk));
615 return SCTP_DISPOSITION_CONSUME;
619 * Respond to a normal COOKIE ECHO chunk.
620 * We are the side that is being asked for an association.
622 * Section: 5.1 Normal Establishment of an Association, D
623 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
624 * with a COOKIE ACK chunk after building a TCB and moving to
625 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
626 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
627 * chunk MUST be the first chunk in the packet.
629 * IMPLEMENTATION NOTE: An implementation may choose to send the
630 * Communication Up notification to the SCTP user upon reception
631 * of a valid COOKIE ECHO chunk.
633 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
634 * D) Rules for packet carrying a COOKIE ECHO
636 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
637 * Initial Tag received in the INIT ACK.
639 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
642 * (endpoint, asoc, chunk)
645 * (asoc, reply_msg, msg_up, timers, counters)
647 * The return value is the disposition of the chunk.
649 sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
650 const struct sctp_endpoint *ep,
651 const struct sctp_association *asoc,
652 const sctp_subtype_t type, void *arg,
653 sctp_cmd_seq_t *commands)
655 struct sctp_chunk *chunk = arg;
656 struct sctp_association *new_asoc;
657 sctp_init_chunk_t *peer_init;
658 struct sctp_chunk *repl;
659 struct sctp_ulpevent *ev, *ai_ev = NULL;
661 struct sctp_chunk *err_chk_p;
664 /* If the packet is an OOTB packet which is temporarily on the
665 * control endpoint, respond with an ABORT.
667 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
668 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
669 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
672 /* Make sure that the COOKIE_ECHO chunk has a valid length.
673 * In this case, we check that we have enough for at least a
674 * chunk header. More detailed verification is done
675 * in sctp_unpack_cookie().
677 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
678 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
680 /* If the endpoint is not listening or if the number of associations
681 * on the TCP-style socket exceed the max backlog, respond with an
685 if (!sctp_sstate(sk, LISTENING) ||
686 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
687 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
689 /* "Decode" the chunk. We have no optional parameters so we
692 chunk->subh.cookie_hdr =
693 (struct sctp_signed_cookie *)chunk->skb->data;
694 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
695 sizeof(sctp_chunkhdr_t)))
698 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
699 * "Z" will reply with a COOKIE ACK chunk after building a TCB
700 * and moving to the ESTABLISHED state.
702 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
706 * If the re-build failed, what is the proper error path
709 * [We should abort the association. --piggy]
712 /* FIXME: Several errors are possible. A bad cookie should
713 * be silently discarded, but think about logging it too.
716 case -SCTP_IERROR_NOMEM:
719 case -SCTP_IERROR_STALE_COOKIE:
720 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
722 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
724 case -SCTP_IERROR_BAD_SIG:
726 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
731 /* Delay state machine commands until later.
733 * Re-build the bind address for the association is done in
734 * the sctp_unpack_cookie() already.
736 /* This is a brand-new association, so these are not yet side
737 * effects--it is safe to run them here.
739 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
741 if (!sctp_process_init(new_asoc, chunk,
742 &chunk->subh.cookie_hdr->c.peer_addr,
743 peer_init, GFP_ATOMIC))
746 /* SCTP-AUTH: Now that we've populate required fields in
747 * sctp_process_init, set up the assocaition shared keys as
748 * necessary so that we can potentially authenticate the ACK
750 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
754 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
755 * is supposed to be authenticated and we have to do delayed
756 * authentication. We've just recreated the association using
757 * the information in the cookie and now it's much easier to
758 * do the authentication.
760 if (chunk->auth_chunk) {
761 struct sctp_chunk auth;
764 /* Make sure that we and the peer are AUTH capable */
765 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
766 sctp_association_free(new_asoc);
767 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
770 /* set-up our fake chunk so that we can process it */
771 auth.skb = chunk->auth_chunk;
772 auth.asoc = chunk->asoc;
773 auth.sctp_hdr = chunk->sctp_hdr;
774 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
775 sizeof(sctp_chunkhdr_t));
776 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
777 auth.transport = chunk->transport;
779 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
780 if (ret != SCTP_IERROR_NO_ERROR) {
781 sctp_association_free(new_asoc);
782 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
786 repl = sctp_make_cookie_ack(new_asoc, chunk);
790 /* RFC 2960 5.1 Normal Establishment of an Association
792 * D) IMPLEMENTATION NOTE: An implementation may choose to
793 * send the Communication Up notification to the SCTP user
794 * upon reception of a valid COOKIE ECHO chunk.
796 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
797 new_asoc->c.sinit_num_ostreams,
798 new_asoc->c.sinit_max_instreams,
803 /* Sockets API Draft Section 5.3.1.6
804 * When a peer sends a Adaptation Layer Indication parameter , SCTP
805 * delivers this notification to inform the application that of the
806 * peers requested adaptation layer.
808 if (new_asoc->peer.adaptation_ind) {
809 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
815 /* Add all the state machine commands now since we've created
816 * everything. This way we don't introduce memory corruptions
817 * during side-effect processing and correclty count established
820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
821 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
822 SCTP_STATE(SCTP_STATE_ESTABLISHED));
823 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
824 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
825 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
827 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
828 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
829 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
831 /* This will send the COOKIE ACK */
832 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
834 /* Queue the ASSOC_CHANGE event */
835 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
837 /* Send up the Adaptation Layer Indication event */
839 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
840 SCTP_ULPEVENT(ai_ev));
842 return SCTP_DISPOSITION_CONSUME;
845 sctp_ulpevent_free(ev);
847 sctp_chunk_free(repl);
849 sctp_association_free(new_asoc);
851 return SCTP_DISPOSITION_NOMEM;
855 * Respond to a normal COOKIE ACK chunk.
856 * We are the side that is asking for an association.
858 * RFC 2960 5.1 Normal Establishment of an Association
860 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
861 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
862 * timer. It may also notify its ULP about the successful
863 * establishment of the association with a Communication Up
864 * notification (see Section 10).
868 * (endpoint, asoc, chunk)
871 * (asoc, reply_msg, msg_up, timers, counters)
873 * The return value is the disposition of the chunk.
875 sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
876 const struct sctp_endpoint *ep,
877 const struct sctp_association *asoc,
878 const sctp_subtype_t type, void *arg,
879 sctp_cmd_seq_t *commands)
881 struct sctp_chunk *chunk = arg;
882 struct sctp_ulpevent *ev;
884 if (!sctp_vtag_verify(chunk, asoc))
885 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
887 /* Verify that the chunk length for the COOKIE-ACK is OK.
888 * If we don't do this, any bundled chunks may be junked.
890 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
891 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
894 /* Reset init error count upon receipt of COOKIE-ACK,
895 * to avoid problems with the managemement of this
896 * counter in stale cookie situations when a transition back
897 * from the COOKIE-ECHOED state to the COOKIE-WAIT
898 * state is performed.
900 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
902 /* RFC 2960 5.1 Normal Establishment of an Association
904 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
905 * from the COOKIE-ECHOED state to the ESTABLISHED state,
906 * stopping the T1-cookie timer.
908 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
909 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
910 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
911 SCTP_STATE(SCTP_STATE_ESTABLISHED));
912 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
913 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
914 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
915 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
916 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
917 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
919 /* It may also notify its ULP about the successful
920 * establishment of the association with a Communication Up
921 * notification (see Section 10).
923 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
924 0, asoc->c.sinit_num_ostreams,
925 asoc->c.sinit_max_instreams,
931 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
933 /* Sockets API Draft Section 5.3.1.6
934 * When a peer sends a Adaptation Layer Indication parameter , SCTP
935 * delivers this notification to inform the application that of the
936 * peers requested adaptation layer.
938 if (asoc->peer.adaptation_ind) {
939 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
943 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
947 return SCTP_DISPOSITION_CONSUME;
949 return SCTP_DISPOSITION_NOMEM;
952 /* Generate and sendout a heartbeat packet. */
953 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
954 const struct sctp_association *asoc,
955 const sctp_subtype_t type,
957 sctp_cmd_seq_t *commands)
959 struct sctp_transport *transport = (struct sctp_transport *) arg;
960 struct sctp_chunk *reply;
962 /* Send a heartbeat to our peer. */
963 reply = sctp_make_heartbeat(asoc, transport);
965 return SCTP_DISPOSITION_NOMEM;
967 /* Set rto_pending indicating that an RTT measurement
968 * is started with this heartbeat chunk.
970 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
971 SCTP_TRANSPORT(transport));
973 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
974 return SCTP_DISPOSITION_CONSUME;
977 /* Generate a HEARTBEAT packet on the given transport. */
978 sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
979 const struct sctp_endpoint *ep,
980 const struct sctp_association *asoc,
981 const sctp_subtype_t type,
983 sctp_cmd_seq_t *commands)
985 struct sctp_transport *transport = (struct sctp_transport *) arg;
987 if (asoc->overall_error_count >= asoc->max_retrans) {
988 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
989 SCTP_ERROR(ETIMEDOUT));
990 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
991 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
992 SCTP_PERR(SCTP_ERROR_NO_ERROR));
993 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
994 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
995 return SCTP_DISPOSITION_DELETE_TCB;
999 * The Sender-specific Heartbeat Info field should normally include
1000 * information about the sender's current time when this HEARTBEAT
1001 * chunk is sent and the destination transport address to which this
1002 * HEARTBEAT is sent (see Section 8.3).
1005 if (transport->param_flags & SPP_HB_ENABLE) {
1006 if (SCTP_DISPOSITION_NOMEM ==
1007 sctp_sf_heartbeat(ep, asoc, type, arg,
1009 return SCTP_DISPOSITION_NOMEM;
1011 /* Set transport error counter and association error counter
1012 * when sending heartbeat.
1014 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1015 SCTP_TRANSPORT(transport));
1017 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1018 SCTP_TRANSPORT(transport));
1019 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1020 SCTP_TRANSPORT(transport));
1022 return SCTP_DISPOSITION_CONSUME;
1026 * Process an heartbeat request.
1028 * Section: 8.3 Path Heartbeat
1029 * The receiver of the HEARTBEAT should immediately respond with a
1030 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1031 * from the received HEARTBEAT chunk.
1033 * Verification Tag: 8.5 Verification Tag [Normal verification]
1034 * When receiving an SCTP packet, the endpoint MUST ensure that the
1035 * value in the Verification Tag field of the received SCTP packet
1036 * matches its own Tag. If the received Verification Tag value does not
1037 * match the receiver's own tag value, the receiver shall silently
1038 * discard the packet and shall not process it any further except for
1039 * those cases listed in Section 8.5.1 below.
1042 * (endpoint, asoc, chunk)
1045 * (asoc, reply_msg, msg_up, timers, counters)
1047 * The return value is the disposition of the chunk.
1049 sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1050 const struct sctp_endpoint *ep,
1051 const struct sctp_association *asoc,
1052 const sctp_subtype_t type,
1054 sctp_cmd_seq_t *commands)
1056 sctp_paramhdr_t *param_hdr;
1057 struct sctp_chunk *chunk = arg;
1058 struct sctp_chunk *reply;
1061 if (!sctp_vtag_verify(chunk, asoc))
1062 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1064 /* Make sure that the HEARTBEAT chunk has a valid length. */
1065 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1066 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1069 /* 8.3 The receiver of the HEARTBEAT should immediately
1070 * respond with a HEARTBEAT ACK that contains the Heartbeat
1071 * Information field copied from the received HEARTBEAT chunk.
1073 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1074 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
1075 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1077 if (ntohs(param_hdr->length) > paylen)
1078 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1079 param_hdr, commands);
1081 if (!pskb_pull(chunk->skb, paylen))
1084 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1088 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1089 return SCTP_DISPOSITION_CONSUME;
1092 return SCTP_DISPOSITION_NOMEM;
1096 * Process the returning HEARTBEAT ACK.
1098 * Section: 8.3 Path Heartbeat
1099 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1100 * should clear the error counter of the destination transport
1101 * address to which the HEARTBEAT was sent, and mark the destination
1102 * transport address as active if it is not so marked. The endpoint may
1103 * optionally report to the upper layer when an inactive destination
1104 * address is marked as active due to the reception of the latest
1105 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1106 * clear the association overall error count as well (as defined
1109 * The receiver of the HEARTBEAT ACK should also perform an RTT
1110 * measurement for that destination transport address using the time
1111 * value carried in the HEARTBEAT ACK chunk.
1113 * Verification Tag: 8.5 Verification Tag [Normal verification]
1116 * (endpoint, asoc, chunk)
1119 * (asoc, reply_msg, msg_up, timers, counters)
1121 * The return value is the disposition of the chunk.
1123 sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1124 const struct sctp_endpoint *ep,
1125 const struct sctp_association *asoc,
1126 const sctp_subtype_t type,
1128 sctp_cmd_seq_t *commands)
1130 struct sctp_chunk *chunk = arg;
1131 union sctp_addr from_addr;
1132 struct sctp_transport *link;
1133 sctp_sender_hb_info_t *hbinfo;
1134 unsigned long max_interval;
1136 if (!sctp_vtag_verify(chunk, asoc))
1137 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1139 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1140 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1141 sizeof(sctp_sender_hb_info_t)))
1142 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1145 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1146 /* Make sure that the length of the parameter is what we expect */
1147 if (ntohs(hbinfo->param_hdr.length) !=
1148 sizeof(sctp_sender_hb_info_t)) {
1149 return SCTP_DISPOSITION_DISCARD;
1152 from_addr = hbinfo->daddr;
1153 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1155 /* This should never happen, but lets log it if so. */
1156 if (unlikely(!link)) {
1157 if (from_addr.sa.sa_family == AF_INET6) {
1158 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1161 &from_addr.v6.sin6_addr);
1163 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1166 &from_addr.v4.sin_addr.s_addr);
1168 return SCTP_DISPOSITION_DISCARD;
1171 /* Validate the 64-bit random nonce. */
1172 if (hbinfo->hb_nonce != link->hb_nonce)
1173 return SCTP_DISPOSITION_DISCARD;
1175 max_interval = link->hbinterval + link->rto;
1177 /* Check if the timestamp looks valid. */
1178 if (time_after(hbinfo->sent_at, jiffies) ||
1179 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1180 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1181 "for transport:%p\n", __func__, link);
1183 return SCTP_DISPOSITION_DISCARD;
1186 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1187 * the HEARTBEAT should clear the error counter of the
1188 * destination transport address to which the HEARTBEAT was
1189 * sent and mark the destination transport address as active if
1190 * it is not so marked.
1192 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1194 return SCTP_DISPOSITION_CONSUME;
1197 /* Helper function to send out an abort for the restart
1200 static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1201 struct sctp_chunk *init,
1202 sctp_cmd_seq_t *commands)
1205 struct sctp_packet *pkt;
1206 union sctp_addr_param *addrparm;
1207 struct sctp_errhdr *errhdr;
1208 struct sctp_endpoint *ep;
1209 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1210 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1212 /* Build the error on the stack. We are way to malloc crazy
1213 * throughout the code today.
1215 errhdr = (struct sctp_errhdr *)buffer;
1216 addrparm = (union sctp_addr_param *)errhdr->variable;
1218 /* Copy into a parm format. */
1219 len = af->to_addr_param(ssa, addrparm);
1220 len += sizeof(sctp_errhdr_t);
1222 errhdr->cause = SCTP_ERROR_RESTART;
1223 errhdr->length = htons(len);
1225 /* Assign to the control socket. */
1226 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1228 /* Association is NULL since this may be a restart attack and we
1229 * want to send back the attacker's vtag.
1231 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1235 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1237 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1239 /* Discard the rest of the inbound packet. */
1240 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1243 /* Even if there is no memory, treat as a failure so
1244 * the packet will get dropped.
1249 static bool list_has_sctp_addr(const struct list_head *list,
1250 union sctp_addr *ipaddr)
1252 struct sctp_transport *addr;
1254 list_for_each_entry(addr, list, transports) {
1255 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1261 /* A restart is occurring, check to make sure no new addresses
1262 * are being added as we may be under a takeover attack.
1264 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1265 const struct sctp_association *asoc,
1266 struct sctp_chunk *init,
1267 sctp_cmd_seq_t *commands)
1269 struct net *net = sock_net(new_asoc->base.sk);
1270 struct sctp_transport *new_addr;
1273 /* Implementor's Guide - Section 5.2.2
1275 * Before responding the endpoint MUST check to see if the
1276 * unexpected INIT adds new addresses to the association. If new
1277 * addresses are added to the association, the endpoint MUST respond
1281 /* Search through all current addresses and make sure
1282 * we aren't adding any new ones.
1284 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1286 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1287 &new_addr->ipaddr)) {
1288 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
1295 /* Return success if all addresses were found. */
1299 /* Populate the verification/tie tags based on overlapping INIT
1302 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1304 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1305 const struct sctp_association *asoc)
1307 switch (asoc->state) {
1309 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1311 case SCTP_STATE_COOKIE_WAIT:
1312 new_asoc->c.my_vtag = asoc->c.my_vtag;
1313 new_asoc->c.my_ttag = asoc->c.my_vtag;
1314 new_asoc->c.peer_ttag = 0;
1317 case SCTP_STATE_COOKIE_ECHOED:
1318 new_asoc->c.my_vtag = asoc->c.my_vtag;
1319 new_asoc->c.my_ttag = asoc->c.my_vtag;
1320 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1323 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1324 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1327 new_asoc->c.my_ttag = asoc->c.my_vtag;
1328 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1332 /* Other parameters for the endpoint SHOULD be copied from the
1333 * existing parameters of the association (e.g. number of
1334 * outbound streams) into the INIT ACK and cookie.
1336 new_asoc->rwnd = asoc->rwnd;
1337 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1338 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1339 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1343 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1346 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1348 * Returns value representing action to be taken. These action values
1349 * correspond to Action/Description values in RFC 2960, Table 2.
1351 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1352 const struct sctp_association *asoc)
1354 /* In this case, the peer may have restarted. */
1355 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1356 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1357 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1358 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1361 /* Collision case B. */
1362 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1363 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1364 (0 == asoc->c.peer_vtag))) {
1368 /* Collision case D. */
1369 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1370 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1373 /* Collision case C. */
1374 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1375 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1376 (0 == new_asoc->c.my_ttag) &&
1377 (0 == new_asoc->c.peer_ttag))
1380 /* No match to any of the special cases; discard this packet. */
1384 /* Common helper routine for both duplicate and simulataneous INIT
1387 static sctp_disposition_t sctp_sf_do_unexpected_init(
1389 const struct sctp_endpoint *ep,
1390 const struct sctp_association *asoc,
1391 const sctp_subtype_t type,
1392 void *arg, sctp_cmd_seq_t *commands)
1394 sctp_disposition_t retval;
1395 struct sctp_chunk *chunk = arg;
1396 struct sctp_chunk *repl;
1397 struct sctp_association *new_asoc;
1398 struct sctp_chunk *err_chunk;
1399 struct sctp_packet *packet;
1400 sctp_unrecognized_param_t *unk_param;
1404 * An endpoint MUST NOT bundle INIT, INIT ACK or
1405 * SHUTDOWN COMPLETE with any other chunks.
1408 * Furthermore, we require that the receiver of an INIT chunk MUST
1409 * enforce these rules by silently discarding an arriving packet
1410 * with an INIT chunk that is bundled with other chunks.
1412 if (!chunk->singleton)
1413 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1415 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1418 if (chunk->sctp_hdr->vtag != 0)
1419 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1421 /* Make sure that the INIT chunk has a valid length.
1422 * In this case, we generate a protocol violation since we have
1423 * an association established.
1425 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1426 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1428 /* Grab the INIT header. */
1429 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1431 /* Tag the variable length parameters. */
1432 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1434 /* Verify the INIT chunk before processing it. */
1436 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1437 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1439 /* This chunk contains fatal error. It is to be discarded.
1440 * Send an ABORT, with causes if there is any.
1443 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1444 (__u8 *)(err_chunk->chunk_hdr) +
1445 sizeof(sctp_chunkhdr_t),
1446 ntohs(err_chunk->chunk_hdr->length) -
1447 sizeof(sctp_chunkhdr_t));
1450 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1451 SCTP_PACKET(packet));
1452 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1453 retval = SCTP_DISPOSITION_CONSUME;
1455 retval = SCTP_DISPOSITION_NOMEM;
1459 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1465 * Other parameters for the endpoint SHOULD be copied from the
1466 * existing parameters of the association (e.g. number of
1467 * outbound streams) into the INIT ACK and cookie.
1468 * FIXME: We are copying parameters from the endpoint not the
1471 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1475 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1476 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1479 /* In the outbound INIT ACK the endpoint MUST copy its current
1480 * Verification Tag and Peers Verification tag into a reserved
1481 * place (local tie-tag and per tie-tag) within the state cookie.
1483 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1484 (sctp_init_chunk_t *)chunk->chunk_hdr,
1488 /* Make sure no new addresses are being added during the
1489 * restart. Do not do this check for COOKIE-WAIT state,
1490 * since there are no peer addresses to check against.
1491 * Upon return an ABORT will have been sent if needed.
1493 if (!sctp_state(asoc, COOKIE_WAIT)) {
1494 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1496 retval = SCTP_DISPOSITION_CONSUME;
1501 sctp_tietags_populate(new_asoc, asoc);
1503 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1505 /* If there are errors need to be reported for unknown parameters,
1506 * make sure to reserve enough room in the INIT ACK for them.
1510 len = ntohs(err_chunk->chunk_hdr->length) -
1511 sizeof(sctp_chunkhdr_t);
1514 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1518 /* If there are errors need to be reported for unknown parameters,
1519 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1523 /* Get the "Unrecognized parameter" parameter(s) out of the
1524 * ERROR chunk generated by sctp_verify_init(). Since the
1525 * error cause code for "unknown parameter" and the
1526 * "Unrecognized parameter" type is the same, we can
1527 * construct the parameters in INIT ACK by copying the
1528 * ERROR causes over.
1530 unk_param = (sctp_unrecognized_param_t *)
1531 ((__u8 *)(err_chunk->chunk_hdr) +
1532 sizeof(sctp_chunkhdr_t));
1533 /* Replace the cause code with the "Unrecognized parameter"
1536 sctp_addto_chunk(repl, len, unk_param);
1539 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1540 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1543 * Note: After sending out INIT ACK with the State Cookie parameter,
1544 * "Z" MUST NOT allocate any resources for this new association.
1545 * Otherwise, "Z" will be vulnerable to resource attacks.
1547 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1548 retval = SCTP_DISPOSITION_CONSUME;
1553 retval = SCTP_DISPOSITION_NOMEM;
1556 sctp_association_free(new_asoc);
1559 sctp_chunk_free(err_chunk);
1564 * Handle simultaneous INIT.
1565 * This means we started an INIT and then we got an INIT request from
1568 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1569 * This usually indicates an initialization collision, i.e., each
1570 * endpoint is attempting, at about the same time, to establish an
1571 * association with the other endpoint.
1573 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1574 * endpoint MUST respond with an INIT ACK using the same parameters it
1575 * sent in its original INIT chunk (including its Verification Tag,
1576 * unchanged). These original parameters are combined with those from the
1577 * newly received INIT chunk. The endpoint shall also generate a State
1578 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1579 * INIT to calculate the State Cookie.
1581 * After that, the endpoint MUST NOT change its state, the T1-init
1582 * timer shall be left running and the corresponding TCB MUST NOT be
1583 * destroyed. The normal procedures for handling State Cookies when
1584 * a TCB exists will resolve the duplicate INITs to a single association.
1586 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1587 * its Tie-Tags with the Tag information of itself and its peer (see
1588 * section 5.2.2 for a description of the Tie-Tags).
1590 * Verification Tag: Not explicit, but an INIT can not have a valid
1591 * verification tag, so we skip the check.
1594 * (endpoint, asoc, chunk)
1597 * (asoc, reply_msg, msg_up, timers, counters)
1599 * The return value is the disposition of the chunk.
1601 sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1602 const struct sctp_endpoint *ep,
1603 const struct sctp_association *asoc,
1604 const sctp_subtype_t type,
1606 sctp_cmd_seq_t *commands)
1608 /* Call helper to do the real work for both simulataneous and
1609 * duplicate INIT chunk handling.
1611 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1615 * Handle duplicated INIT messages. These are usually delayed
1618 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1619 * COOKIE-ECHOED and COOKIE-WAIT
1621 * Unless otherwise stated, upon reception of an unexpected INIT for
1622 * this association, the endpoint shall generate an INIT ACK with a
1623 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1624 * current Verification Tag and peer's Verification Tag into a reserved
1625 * place within the state cookie. We shall refer to these locations as
1626 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1627 * containing this INIT ACK MUST carry a Verification Tag value equal to
1628 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1629 * MUST contain a new Initiation Tag (randomly generated see Section
1630 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1631 * existing parameters of the association (e.g. number of outbound
1632 * streams) into the INIT ACK and cookie.
1634 * After sending out the INIT ACK, the endpoint shall take no further
1635 * actions, i.e., the existing association, including its current state,
1636 * and the corresponding TCB MUST NOT be changed.
1638 * Note: Only when a TCB exists and the association is not in a COOKIE-
1639 * WAIT state are the Tie-Tags populated. For a normal association INIT
1640 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1641 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1642 * State Cookie are populated as specified in section 5.2.1.
1644 * Verification Tag: Not specified, but an INIT has no way of knowing
1645 * what the verification tag could be, so we ignore it.
1648 * (endpoint, asoc, chunk)
1651 * (asoc, reply_msg, msg_up, timers, counters)
1653 * The return value is the disposition of the chunk.
1655 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1656 const struct sctp_endpoint *ep,
1657 const struct sctp_association *asoc,
1658 const sctp_subtype_t type,
1660 sctp_cmd_seq_t *commands)
1662 /* Call helper to do the real work for both simulataneous and
1663 * duplicate INIT chunk handling.
1665 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1670 * Unexpected INIT-ACK handler.
1673 * If an INIT ACK received by an endpoint in any state other than the
1674 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1675 * An unexpected INIT ACK usually indicates the processing of an old or
1676 * duplicated INIT chunk.
1678 sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1679 const struct sctp_endpoint *ep,
1680 const struct sctp_association *asoc,
1681 const sctp_subtype_t type,
1682 void *arg, sctp_cmd_seq_t *commands)
1684 /* Per the above section, we'll discard the chunk if we have an
1685 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1687 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
1688 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
1690 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
1693 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1696 * A) In this case, the peer may have restarted.
1698 static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1699 const struct sctp_endpoint *ep,
1700 const struct sctp_association *asoc,
1701 struct sctp_chunk *chunk,
1702 sctp_cmd_seq_t *commands,
1703 struct sctp_association *new_asoc)
1705 sctp_init_chunk_t *peer_init;
1706 struct sctp_ulpevent *ev;
1707 struct sctp_chunk *repl;
1708 struct sctp_chunk *err;
1709 sctp_disposition_t disposition;
1711 /* new_asoc is a brand-new association, so these are not yet
1712 * side effects--it is safe to run them here.
1714 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1716 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1720 /* Make sure no new addresses are being added during the
1721 * restart. Though this is a pretty complicated attack
1722 * since you'd have to get inside the cookie.
1724 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1725 return SCTP_DISPOSITION_CONSUME;
1728 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1729 * the peer has restarted (Action A), it MUST NOT setup a new
1730 * association but instead resend the SHUTDOWN ACK and send an ERROR
1731 * chunk with a "Cookie Received while Shutting Down" error cause to
1734 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1735 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1736 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1738 if (SCTP_DISPOSITION_NOMEM == disposition)
1741 err = sctp_make_op_error(asoc, chunk,
1742 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1745 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1748 return SCTP_DISPOSITION_CONSUME;
1751 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1752 * data. Consider the optional choice of resending of this data.
1754 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1755 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1756 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1757 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1759 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1760 * and ASCONF-ACK cache.
1762 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1763 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1764 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1766 repl = sctp_make_cookie_ack(new_asoc, chunk);
1770 /* Report association restart to upper layer. */
1771 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1772 new_asoc->c.sinit_num_ostreams,
1773 new_asoc->c.sinit_max_instreams,
1778 /* Update the content of current association. */
1779 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1780 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1781 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
1782 (sctp_sstate(asoc->base.sk, CLOSING) ||
1783 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1784 /* if were currently in SHUTDOWN_PENDING, but the socket
1785 * has been closed by user, don't transition to ESTABLISHED.
1786 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1788 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1789 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1790 SCTP_ST_CHUNK(0), NULL,
1793 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1794 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1795 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1797 return SCTP_DISPOSITION_CONSUME;
1800 sctp_chunk_free(repl);
1802 return SCTP_DISPOSITION_NOMEM;
1805 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1808 * B) In this case, both sides may be attempting to start an association
1809 * at about the same time but the peer endpoint started its INIT
1810 * after responding to the local endpoint's INIT
1812 /* This case represents an initialization collision. */
1813 static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1814 const struct sctp_endpoint *ep,
1815 const struct sctp_association *asoc,
1816 struct sctp_chunk *chunk,
1817 sctp_cmd_seq_t *commands,
1818 struct sctp_association *new_asoc)
1820 sctp_init_chunk_t *peer_init;
1821 struct sctp_chunk *repl;
1823 /* new_asoc is a brand-new association, so these are not yet
1824 * side effects--it is safe to run them here.
1826 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1827 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1831 /* Update the content of current association. */
1832 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1833 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1834 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1835 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1836 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1838 repl = sctp_make_cookie_ack(new_asoc, chunk);
1842 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1844 /* RFC 2960 5.1 Normal Establishment of an Association
1846 * D) IMPLEMENTATION NOTE: An implementation may choose to
1847 * send the Communication Up notification to the SCTP user
1848 * upon reception of a valid COOKIE ECHO chunk.
1850 * Sadly, this needs to be implemented as a side-effect, because
1851 * we are not guaranteed to have set the association id of the real
1852 * association and so these notifications need to be delayed until
1853 * the association id is allocated.
1856 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1858 /* Sockets API Draft Section 5.3.1.6
1859 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1860 * delivers this notification to inform the application that of the
1861 * peers requested adaptation layer.
1863 * This also needs to be done as a side effect for the same reason as
1866 if (asoc->peer.adaptation_ind)
1867 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1869 return SCTP_DISPOSITION_CONSUME;
1872 return SCTP_DISPOSITION_NOMEM;
1875 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1878 * C) In this case, the local endpoint's cookie has arrived late.
1879 * Before it arrived, the local endpoint sent an INIT and received an
1880 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1881 * but a new tag of its own.
1883 /* This case represents an initialization collision. */
1884 static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1885 const struct sctp_endpoint *ep,
1886 const struct sctp_association *asoc,
1887 struct sctp_chunk *chunk,
1888 sctp_cmd_seq_t *commands,
1889 struct sctp_association *new_asoc)
1891 /* The cookie should be silently discarded.
1892 * The endpoint SHOULD NOT change states and should leave
1893 * any timers running.
1895 return SCTP_DISPOSITION_DISCARD;
1898 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1902 * D) When both local and remote tags match the endpoint should always
1903 * enter the ESTABLISHED state, if it has not already done so.
1905 /* This case represents an initialization collision. */
1906 static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1907 const struct sctp_endpoint *ep,
1908 const struct sctp_association *asoc,
1909 struct sctp_chunk *chunk,
1910 sctp_cmd_seq_t *commands,
1911 struct sctp_association *new_asoc)
1913 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1914 struct sctp_chunk *repl;
1916 /* Clarification from Implementor's Guide:
1917 * D) When both local and remote tags match the endpoint should
1918 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1919 * It should stop any cookie timer that may be running and send
1923 /* Don't accidentally move back into established state. */
1924 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1925 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1926 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1927 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1928 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1929 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1930 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1933 /* RFC 2960 5.1 Normal Establishment of an Association
1935 * D) IMPLEMENTATION NOTE: An implementation may choose
1936 * to send the Communication Up notification to the
1937 * SCTP user upon reception of a valid COOKIE
1940 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1942 asoc->c.sinit_num_ostreams,
1943 asoc->c.sinit_max_instreams,
1948 /* Sockets API Draft Section 5.3.1.6
1949 * When a peer sends a Adaptation Layer Indication parameter,
1950 * SCTP delivers this notification to inform the application
1951 * that of the peers requested adaptation layer.
1953 if (asoc->peer.adaptation_ind) {
1954 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1962 repl = sctp_make_cookie_ack(new_asoc, chunk);
1966 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1969 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1972 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1973 SCTP_ULPEVENT(ai_ev));
1975 return SCTP_DISPOSITION_CONSUME;
1979 sctp_ulpevent_free(ai_ev);
1981 sctp_ulpevent_free(ev);
1982 return SCTP_DISPOSITION_NOMEM;
1986 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1987 * chunk was retransmitted and then delayed in the network.
1989 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1991 * Verification Tag: None. Do cookie validation.
1994 * (endpoint, asoc, chunk)
1997 * (asoc, reply_msg, msg_up, timers, counters)
1999 * The return value is the disposition of the chunk.
2001 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
2002 const struct sctp_endpoint *ep,
2003 const struct sctp_association *asoc,
2004 const sctp_subtype_t type,
2006 sctp_cmd_seq_t *commands)
2008 sctp_disposition_t retval;
2009 struct sctp_chunk *chunk = arg;
2010 struct sctp_association *new_asoc;
2013 struct sctp_chunk *err_chk_p;
2015 /* Make sure that the chunk has a valid length from the protocol
2016 * perspective. In this case check to make sure we have at least
2017 * enough for the chunk header. Cookie length verification is
2020 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2021 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2024 /* "Decode" the chunk. We have no optional parameters so we
2025 * are in good shape.
2027 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2028 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2029 sizeof(sctp_chunkhdr_t)))
2032 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2033 * of a duplicate COOKIE ECHO match the Verification Tags of the
2034 * current association, consider the State Cookie valid even if
2035 * the lifespan is exceeded.
2037 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2041 * If the re-build failed, what is the proper error path
2044 * [We should abort the association. --piggy]
2047 /* FIXME: Several errors are possible. A bad cookie should
2048 * be silently discarded, but think about logging it too.
2051 case -SCTP_IERROR_NOMEM:
2054 case -SCTP_IERROR_STALE_COOKIE:
2055 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2057 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2058 case -SCTP_IERROR_BAD_SIG:
2060 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2064 /* Compare the tie_tag in cookie with the verification tag of
2065 * current association.
2067 action = sctp_tietags_compare(new_asoc, asoc);
2070 case 'A': /* Association restart. */
2071 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2075 case 'B': /* Collision case B. */
2076 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2080 case 'C': /* Collision case C. */
2081 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2085 case 'D': /* Collision case D. */
2086 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2090 default: /* Discard packet for all others. */
2091 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2095 /* Delete the tempory new association. */
2096 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2097 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2099 /* Restore association pointer to provide SCTP command interpeter
2100 * with a valid context in case it needs to manipulate
2102 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2103 SCTP_ASOC((struct sctp_association *)asoc));
2108 return SCTP_DISPOSITION_NOMEM;
2112 * Process an ABORT. (SHUTDOWN-PENDING state)
2114 * See sctp_sf_do_9_1_abort().
2116 sctp_disposition_t sctp_sf_shutdown_pending_abort(
2118 const struct sctp_endpoint *ep,
2119 const struct sctp_association *asoc,
2120 const sctp_subtype_t type,
2122 sctp_cmd_seq_t *commands)
2124 struct sctp_chunk *chunk = arg;
2126 if (!sctp_vtag_verify_either(chunk, asoc))
2127 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2129 /* Make sure that the ABORT chunk has a valid length.
2130 * Since this is an ABORT chunk, we have to discard it
2131 * because of the following text:
2132 * RFC 2960, Section 3.3.7
2133 * If an endpoint receives an ABORT with a format error or for an
2134 * association that doesn't exist, it MUST silently discard it.
2135 * Because the length is "invalid", we can't really discard just
2136 * as we do not know its true length. So, to be safe, discard the
2139 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2140 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2142 /* ADD-IP: Special case for ABORT chunks
2143 * F4) One special consideration is that ABORT Chunks arriving
2144 * destined to the IP address being deleted MUST be
2145 * ignored (see Section 5.3.1 for further details).
2147 if (SCTP_ADDR_DEL ==
2148 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2149 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2151 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2155 * Process an ABORT. (SHUTDOWN-SENT state)
2157 * See sctp_sf_do_9_1_abort().
2159 sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2160 const struct sctp_endpoint *ep,
2161 const struct sctp_association *asoc,
2162 const sctp_subtype_t type,
2164 sctp_cmd_seq_t *commands)
2166 struct sctp_chunk *chunk = arg;
2168 if (!sctp_vtag_verify_either(chunk, asoc))
2169 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2171 /* Make sure that the ABORT chunk has a valid length.
2172 * Since this is an ABORT chunk, we have to discard it
2173 * because of the following text:
2174 * RFC 2960, Section 3.3.7
2175 * If an endpoint receives an ABORT with a format error or for an
2176 * association that doesn't exist, it MUST silently discard it.
2177 * Because the length is "invalid", we can't really discard just
2178 * as we do not know its true length. So, to be safe, discard the
2181 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2182 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2184 /* ADD-IP: Special case for ABORT chunks
2185 * F4) One special consideration is that ABORT Chunks arriving
2186 * destined to the IP address being deleted MUST be
2187 * ignored (see Section 5.3.1 for further details).
2189 if (SCTP_ADDR_DEL ==
2190 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2191 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2193 /* Stop the T2-shutdown timer. */
2194 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2195 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2197 /* Stop the T5-shutdown guard timer. */
2198 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2199 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2201 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2205 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2207 * See sctp_sf_do_9_1_abort().
2209 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2211 const struct sctp_endpoint *ep,
2212 const struct sctp_association *asoc,
2213 const sctp_subtype_t type,
2215 sctp_cmd_seq_t *commands)
2217 /* The same T2 timer, so we should be able to use
2218 * common function with the SHUTDOWN-SENT state.
2220 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2224 * Handle an Error received in COOKIE_ECHOED state.
2226 * Only handle the error type of stale COOKIE Error, the other errors will
2230 * (endpoint, asoc, chunk)
2233 * (asoc, reply_msg, msg_up, timers, counters)
2235 * The return value is the disposition of the chunk.
2237 sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2238 const struct sctp_endpoint *ep,
2239 const struct sctp_association *asoc,
2240 const sctp_subtype_t type,
2242 sctp_cmd_seq_t *commands)
2244 struct sctp_chunk *chunk = arg;
2247 if (!sctp_vtag_verify(chunk, asoc))
2248 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2250 /* Make sure that the ERROR chunk has a valid length.
2251 * The parameter walking depends on this as well.
2253 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2254 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2257 /* Process the error here */
2258 /* FUTURE FIXME: When PR-SCTP related and other optional
2259 * parms are emitted, this will have to change to handle multiple
2262 sctp_walk_errors(err, chunk->chunk_hdr) {
2263 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2264 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2268 /* It is possible to have malformed error causes, and that
2269 * will cause us to end the walk early. However, since
2270 * we are discarding the packet, there should be no adverse
2273 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2277 * Handle a Stale COOKIE Error
2279 * Section: 5.2.6 Handle Stale COOKIE Error
2280 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2281 * one of the following three alternatives.
2283 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2284 * Preservative parameter requesting an extension to the lifetime of
2285 * the State Cookie. When calculating the time extension, an
2286 * implementation SHOULD use the RTT information measured based on the
2287 * previous COOKIE ECHO / ERROR exchange, and should add no more
2288 * than 1 second beyond the measured RTT, due to long State Cookie
2289 * lifetimes making the endpoint more subject to a replay attack.
2291 * Verification Tag: Not explicit, but safe to ignore.
2294 * (endpoint, asoc, chunk)
2297 * (asoc, reply_msg, msg_up, timers, counters)
2299 * The return value is the disposition of the chunk.
2301 static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2302 const struct sctp_endpoint *ep,
2303 const struct sctp_association *asoc,
2304 const sctp_subtype_t type,
2306 sctp_cmd_seq_t *commands)
2308 struct sctp_chunk *chunk = arg;
2310 sctp_cookie_preserve_param_t bht;
2312 struct sctp_chunk *reply;
2313 struct sctp_bind_addr *bp;
2314 int attempts = asoc->init_err_counter + 1;
2316 if (attempts > asoc->max_init_attempts) {
2317 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2318 SCTP_ERROR(ETIMEDOUT));
2319 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2320 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2321 return SCTP_DISPOSITION_DELETE_TCB;
2324 err = (sctp_errhdr_t *)(chunk->skb->data);
2326 /* When calculating the time extension, an implementation
2327 * SHOULD use the RTT information measured based on the
2328 * previous COOKIE ECHO / ERROR exchange, and should add no
2329 * more than 1 second beyond the measured RTT, due to long
2330 * State Cookie lifetimes making the endpoint more subject to
2332 * Measure of Staleness's unit is usec. (1/1000000 sec)
2333 * Suggested Cookie Life-span Increment's unit is msec.
2335 * In general, if you use the suggested cookie life, the value
2336 * found in the field of measure of staleness should be doubled
2337 * to give ample time to retransmit the new cookie and thus
2338 * yield a higher probability of success on the reattempt.
2340 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2341 stale = (stale * 2) / 1000;
2343 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2344 bht.param_hdr.length = htons(sizeof(bht));
2345 bht.lifespan_increment = htonl(stale);
2347 /* Build that new INIT chunk. */
2348 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2349 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2353 sctp_addto_chunk(reply, sizeof(bht), &bht);
2355 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2356 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2358 /* Stop pending T3-rtx and heartbeat timers */
2359 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2360 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2362 /* Delete non-primary peer ip addresses since we are transitioning
2363 * back to the COOKIE-WAIT state
2365 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2367 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2370 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2371 SCTP_TRANSPORT(asoc->peer.primary_path));
2373 /* Cast away the const modifier, as we want to just
2374 * rerun it through as a sideffect.
2376 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2378 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2379 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2380 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2381 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2382 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2383 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2385 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2387 return SCTP_DISPOSITION_CONSUME;
2390 return SCTP_DISPOSITION_NOMEM;
2397 * After checking the Verification Tag, the receiving endpoint shall
2398 * remove the association from its record, and shall report the
2399 * termination to its upper layer.
2401 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2402 * B) Rules for packet carrying ABORT:
2404 * - The endpoint shall always fill in the Verification Tag field of the
2405 * outbound packet with the destination endpoint's tag value if it
2408 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2409 * MUST follow the procedure described in Section 8.4.
2411 * - The receiver MUST accept the packet if the Verification Tag
2412 * matches either its own tag, OR the tag of its peer. Otherwise, the
2413 * receiver MUST silently discard the packet and take no further
2417 * (endpoint, asoc, chunk)
2420 * (asoc, reply_msg, msg_up, timers, counters)
2422 * The return value is the disposition of the chunk.
2424 sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2425 const struct sctp_endpoint *ep,
2426 const struct sctp_association *asoc,
2427 const sctp_subtype_t type,
2429 sctp_cmd_seq_t *commands)
2431 struct sctp_chunk *chunk = arg;
2433 if (!sctp_vtag_verify_either(chunk, asoc))
2434 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2436 /* Make sure that the ABORT chunk has a valid length.
2437 * Since this is an ABORT chunk, we have to discard it
2438 * because of the following text:
2439 * RFC 2960, Section 3.3.7
2440 * If an endpoint receives an ABORT with a format error or for an
2441 * association that doesn't exist, it MUST silently discard it.
2442 * Because the length is "invalid", we can't really discard just
2443 * as we do not know its true length. So, to be safe, discard the
2446 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2447 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2449 /* ADD-IP: Special case for ABORT chunks
2450 * F4) One special consideration is that ABORT Chunks arriving
2451 * destined to the IP address being deleted MUST be
2452 * ignored (see Section 5.3.1 for further details).
2454 if (SCTP_ADDR_DEL ==
2455 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2456 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2458 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2461 static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2462 const struct sctp_endpoint *ep,
2463 const struct sctp_association *asoc,
2464 const sctp_subtype_t type,
2466 sctp_cmd_seq_t *commands)
2468 struct sctp_chunk *chunk = arg;
2470 __be16 error = SCTP_ERROR_NO_ERROR;
2472 /* See if we have an error cause code in the chunk. */
2473 len = ntohs(chunk->chunk_hdr->length);
2474 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2477 sctp_walk_errors(err, chunk->chunk_hdr);
2478 if ((void *)err != (void *)chunk->chunk_end)
2479 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2481 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2484 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2485 /* ASSOC_FAILED will DELETE_TCB. */
2486 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2487 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2488 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2490 return SCTP_DISPOSITION_ABORT;
2494 * Process an ABORT. (COOKIE-WAIT state)
2496 * See sctp_sf_do_9_1_abort() above.
2498 sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2499 const struct sctp_endpoint *ep,
2500 const struct sctp_association *asoc,
2501 const sctp_subtype_t type,
2503 sctp_cmd_seq_t *commands)
2505 struct sctp_chunk *chunk = arg;
2507 __be16 error = SCTP_ERROR_NO_ERROR;
2509 if (!sctp_vtag_verify_either(chunk, asoc))
2510 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2512 /* Make sure that the ABORT chunk has a valid length.
2513 * Since this is an ABORT chunk, we have to discard it
2514 * because of the following text:
2515 * RFC 2960, Section 3.3.7
2516 * If an endpoint receives an ABORT with a format error or for an
2517 * association that doesn't exist, it MUST silently discard it.
2518 * Because the length is "invalid", we can't really discard just
2519 * as we do not know its true length. So, to be safe, discard the
2522 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2523 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2525 /* See if we have an error cause code in the chunk. */
2526 len = ntohs(chunk->chunk_hdr->length);
2527 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2528 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2530 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2535 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2537 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2538 const struct sctp_endpoint *ep,
2539 const struct sctp_association *asoc,
2540 const sctp_subtype_t type,
2542 sctp_cmd_seq_t *commands)
2544 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2546 (struct sctp_transport *)arg);
2550 * Process an ABORT. (COOKIE-ECHOED state)
2552 sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2553 const struct sctp_endpoint *ep,
2554 const struct sctp_association *asoc,
2555 const sctp_subtype_t type,
2557 sctp_cmd_seq_t *commands)
2559 /* There is a single T1 timer, so we should be able to use
2560 * common function with the COOKIE-WAIT state.
2562 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2566 * Stop T1 timer and abort association with "INIT failed".
2568 * This is common code called by several sctp_sf_*_abort() functions above.
2570 static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2571 sctp_cmd_seq_t *commands,
2572 __be16 error, int sk_err,
2573 const struct sctp_association *asoc,
2574 struct sctp_transport *transport)
2576 pr_debug("%s: ABORT received (INIT)\n", __func__);
2578 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2579 SCTP_STATE(SCTP_STATE_CLOSED));
2580 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2581 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2582 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2583 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2584 /* CMD_INIT_FAILED will DELETE_TCB. */
2585 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2588 return SCTP_DISPOSITION_ABORT;
2592 * sctp_sf_do_9_2_shut
2595 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2596 * - enter the SHUTDOWN-RECEIVED state,
2598 * - stop accepting new data from its SCTP user
2600 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2601 * that all its outstanding DATA chunks have been received by the
2604 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2605 * send a SHUTDOWN in response to a ULP request. And should discard
2606 * subsequent SHUTDOWN chunks.
2608 * If there are still outstanding DATA chunks left, the SHUTDOWN
2609 * receiver shall continue to follow normal data transmission
2610 * procedures defined in Section 6 until all outstanding DATA chunks
2611 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2612 * new data from its SCTP user.
2614 * Verification Tag: 8.5 Verification Tag [Normal verification]
2617 * (endpoint, asoc, chunk)
2620 * (asoc, reply_msg, msg_up, timers, counters)
2622 * The return value is the disposition of the chunk.
2624 sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2625 const struct sctp_endpoint *ep,
2626 const struct sctp_association *asoc,
2627 const sctp_subtype_t type,
2629 sctp_cmd_seq_t *commands)
2631 struct sctp_chunk *chunk = arg;
2632 sctp_shutdownhdr_t *sdh;
2633 sctp_disposition_t disposition;
2634 struct sctp_ulpevent *ev;
2637 if (!sctp_vtag_verify(chunk, asoc))
2638 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2640 /* Make sure that the SHUTDOWN chunk has a valid length. */
2641 if (!sctp_chunk_length_valid(chunk,
2642 sizeof(struct sctp_shutdown_chunk_t)))
2643 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2646 /* Convert the elaborate header. */
2647 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2648 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2649 chunk->subh.shutdown_hdr = sdh;
2650 ctsn = ntohl(sdh->cum_tsn_ack);
2652 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2653 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2654 asoc->ctsn_ack_point);
2656 return SCTP_DISPOSITION_DISCARD;
2659 /* If Cumulative TSN Ack beyond the max tsn currently
2660 * send, terminating the association and respond to the
2661 * sender with an ABORT.
2663 if (!TSN_lt(ctsn, asoc->next_tsn))
2664 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2666 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2667 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2668 * inform the application that it should cease sending data.
2670 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2672 disposition = SCTP_DISPOSITION_NOMEM;
2675 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2677 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2678 * - enter the SHUTDOWN-RECEIVED state,
2679 * - stop accepting new data from its SCTP user
2681 * [This is implicit in the new state.]
2683 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2684 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2685 disposition = SCTP_DISPOSITION_CONSUME;
2687 if (sctp_outq_is_empty(&asoc->outqueue)) {
2688 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2692 if (SCTP_DISPOSITION_NOMEM == disposition)
2695 /* - verify, by checking the Cumulative TSN Ack field of the
2696 * chunk, that all its outstanding DATA chunks have been
2697 * received by the SHUTDOWN sender.
2699 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2700 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2707 * sctp_sf_do_9_2_shut_ctsn
2709 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2710 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2711 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2712 * MUST be processed.
2714 sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2715 const struct sctp_endpoint *ep,
2716 const struct sctp_association *asoc,
2717 const sctp_subtype_t type,
2719 sctp_cmd_seq_t *commands)
2721 struct sctp_chunk *chunk = arg;
2722 sctp_shutdownhdr_t *sdh;
2725 if (!sctp_vtag_verify(chunk, asoc))
2726 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2728 /* Make sure that the SHUTDOWN chunk has a valid length. */
2729 if (!sctp_chunk_length_valid(chunk,
2730 sizeof(struct sctp_shutdown_chunk_t)))
2731 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2734 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2735 ctsn = ntohl(sdh->cum_tsn_ack);
2737 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2738 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2739 asoc->ctsn_ack_point);
2741 return SCTP_DISPOSITION_DISCARD;
2744 /* If Cumulative TSN Ack beyond the max tsn currently
2745 * send, terminating the association and respond to the
2746 * sender with an ABORT.
2748 if (!TSN_lt(ctsn, asoc->next_tsn))
2749 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2751 /* verify, by checking the Cumulative TSN Ack field of the
2752 * chunk, that all its outstanding DATA chunks have been
2753 * received by the SHUTDOWN sender.
2755 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2756 SCTP_BE32(sdh->cum_tsn_ack));
2758 return SCTP_DISPOSITION_CONSUME;
2762 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2763 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2764 * transport addresses (either in the IP addresses or in the INIT chunk)
2765 * that belong to this association, it should discard the INIT chunk and
2766 * retransmit the SHUTDOWN ACK chunk.
2768 sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2769 const struct sctp_endpoint *ep,
2770 const struct sctp_association *asoc,
2771 const sctp_subtype_t type,
2773 sctp_cmd_seq_t *commands)
2775 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2776 struct sctp_chunk *reply;
2778 /* Make sure that the chunk has a valid length */
2779 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2780 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2783 /* Since we are not going to really process this INIT, there
2784 * is no point in verifying chunk boundries. Just generate
2787 reply = sctp_make_shutdown_ack(asoc, chunk);
2791 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2792 * the T2-SHUTDOWN timer.
2794 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2796 /* and restart the T2-shutdown timer. */
2797 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2798 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2800 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2802 return SCTP_DISPOSITION_CONSUME;
2804 return SCTP_DISPOSITION_NOMEM;
2808 * sctp_sf_do_ecn_cwr
2810 * Section: Appendix A: Explicit Congestion Notification
2814 * RFC 2481 details a specific bit for a sender to send in the header of
2815 * its next outbound TCP segment to indicate to its peer that it has
2816 * reduced its congestion window. This is termed the CWR bit. For
2817 * SCTP the same indication is made by including the CWR chunk.
2818 * This chunk contains one data element, i.e. the TSN number that
2819 * was sent in the ECNE chunk. This element represents the lowest
2820 * TSN number in the datagram that was originally marked with the
2823 * Verification Tag: 8.5 Verification Tag [Normal verification]
2825 * (endpoint, asoc, chunk)
2828 * (asoc, reply_msg, msg_up, timers, counters)
2830 * The return value is the disposition of the chunk.
2832 sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2833 const struct sctp_endpoint *ep,
2834 const struct sctp_association *asoc,
2835 const sctp_subtype_t type,
2837 sctp_cmd_seq_t *commands)
2840 struct sctp_chunk *chunk = arg;
2843 if (!sctp_vtag_verify(chunk, asoc))
2844 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2846 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2847 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2850 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2851 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2853 lowest_tsn = ntohl(cwr->lowest_tsn);
2855 /* Does this CWR ack the last sent congestion notification? */
2856 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2857 /* Stop sending ECNE. */
2858 sctp_add_cmd_sf(commands,
2860 SCTP_U32(lowest_tsn));
2862 return SCTP_DISPOSITION_CONSUME;
2868 * Section: Appendix A: Explicit Congestion Notification
2872 * RFC 2481 details a specific bit for a receiver to send back in its
2873 * TCP acknowledgements to notify the sender of the Congestion
2874 * Experienced (CE) bit having arrived from the network. For SCTP this
2875 * same indication is made by including the ECNE chunk. This chunk
2876 * contains one data element, i.e. the lowest TSN associated with the IP
2877 * datagram marked with the CE bit.....
2879 * Verification Tag: 8.5 Verification Tag [Normal verification]
2881 * (endpoint, asoc, chunk)
2884 * (asoc, reply_msg, msg_up, timers, counters)
2886 * The return value is the disposition of the chunk.
2888 sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2889 const struct sctp_endpoint *ep,
2890 const struct sctp_association *asoc,
2891 const sctp_subtype_t type,
2893 sctp_cmd_seq_t *commands)
2895 sctp_ecnehdr_t *ecne;
2896 struct sctp_chunk *chunk = arg;
2898 if (!sctp_vtag_verify(chunk, asoc))
2899 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2901 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2902 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2905 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2906 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2908 /* If this is a newer ECNE than the last CWR packet we sent out */
2909 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2910 SCTP_U32(ntohl(ecne->lowest_tsn)));
2912 return SCTP_DISPOSITION_CONSUME;
2916 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2918 * The SCTP endpoint MUST always acknowledge the reception of each valid
2921 * The guidelines on delayed acknowledgement algorithm specified in
2922 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2923 * acknowledgement SHOULD be generated for at least every second packet
2924 * (not every second DATA chunk) received, and SHOULD be generated within
2925 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2926 * situations it may be beneficial for an SCTP transmitter to be more
2927 * conservative than the algorithms detailed in this document allow.
2928 * However, an SCTP transmitter MUST NOT be more aggressive than the
2929 * following algorithms allow.
2931 * A SCTP receiver MUST NOT generate more than one SACK for every
2932 * incoming packet, other than to update the offered window as the
2933 * receiving application consumes new data.
2935 * Verification Tag: 8.5 Verification Tag [Normal verification]
2938 * (endpoint, asoc, chunk)
2941 * (asoc, reply_msg, msg_up, timers, counters)
2943 * The return value is the disposition of the chunk.
2945 sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2946 const struct sctp_endpoint *ep,
2947 const struct sctp_association *asoc,
2948 const sctp_subtype_t type,
2950 sctp_cmd_seq_t *commands)
2952 struct sctp_chunk *chunk = arg;
2953 sctp_arg_t force = SCTP_NOFORCE();
2956 if (!sctp_vtag_verify(chunk, asoc)) {
2957 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2959 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2962 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2963 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2966 error = sctp_eat_data(asoc, chunk, commands);
2968 case SCTP_IERROR_NO_ERROR:
2970 case SCTP_IERROR_HIGH_TSN:
2971 case SCTP_IERROR_BAD_STREAM:
2972 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2973 goto discard_noforce;
2974 case SCTP_IERROR_DUP_TSN:
2975 case SCTP_IERROR_IGNORE_TSN:
2976 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2978 case SCTP_IERROR_NO_DATA:
2980 case SCTP_IERROR_PROTO_VIOLATION:
2981 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
2982 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
2987 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2988 force = SCTP_FORCE();
2990 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
2991 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2992 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2995 /* If this is the last chunk in a packet, we need to count it
2996 * toward sack generation. Note that we need to SACK every
2997 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2998 * THEM. We elect to NOT generate SACK's if the chunk fails
2999 * the verification tag test.
3001 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3003 * The SCTP endpoint MUST always acknowledge the reception of
3004 * each valid DATA chunk.
3006 * The guidelines on delayed acknowledgement algorithm
3007 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3008 * Specifically, an acknowledgement SHOULD be generated for at
3009 * least every second packet (not every second DATA chunk)
3010 * received, and SHOULD be generated within 200 ms of the
3011 * arrival of any unacknowledged DATA chunk. In some
3012 * situations it may be beneficial for an SCTP transmitter to
3013 * be more conservative than the algorithms detailed in this
3014 * document allow. However, an SCTP transmitter MUST NOT be
3015 * more aggressive than the following algorithms allow.
3017 if (chunk->end_of_packet)
3018 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3020 return SCTP_DISPOSITION_CONSUME;
3023 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3025 * When a packet arrives with duplicate DATA chunk(s) and with
3026 * no new DATA chunk(s), the endpoint MUST immediately send a
3027 * SACK with no delay. If a packet arrives with duplicate
3028 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3029 * MAY immediately send a SACK. Normally receipt of duplicate
3030 * DATA chunks will occur when the original SACK chunk was lost
3031 * and the peer's RTO has expired. The duplicate TSN number(s)
3032 * SHOULD be reported in the SACK as duplicate.
3034 /* In our case, we split the MAY SACK advice up whether or not
3035 * the last chunk is a duplicate.'
3037 if (chunk->end_of_packet)
3038 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3039 return SCTP_DISPOSITION_DISCARD;
3042 if (chunk->end_of_packet)
3043 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3045 return SCTP_DISPOSITION_DISCARD;
3047 return SCTP_DISPOSITION_CONSUME;
3052 * sctp_sf_eat_data_fast_4_4
3055 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3056 * DATA chunks without delay.
3058 * Verification Tag: 8.5 Verification Tag [Normal verification]
3060 * (endpoint, asoc, chunk)
3063 * (asoc, reply_msg, msg_up, timers, counters)
3065 * The return value is the disposition of the chunk.
3067 sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3068 const struct sctp_endpoint *ep,
3069 const struct sctp_association *asoc,
3070 const sctp_subtype_t type,
3072 sctp_cmd_seq_t *commands)
3074 struct sctp_chunk *chunk = arg;
3077 if (!sctp_vtag_verify(chunk, asoc)) {
3078 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3080 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3083 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3084 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3087 error = sctp_eat_data(asoc, chunk, commands);
3089 case SCTP_IERROR_NO_ERROR:
3090 case SCTP_IERROR_HIGH_TSN:
3091 case SCTP_IERROR_DUP_TSN:
3092 case SCTP_IERROR_IGNORE_TSN:
3093 case SCTP_IERROR_BAD_STREAM:
3095 case SCTP_IERROR_NO_DATA:
3097 case SCTP_IERROR_PROTO_VIOLATION:
3098 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3099 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3104 /* Go a head and force a SACK, since we are shutting down. */
3106 /* Implementor's Guide.
3108 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3109 * respond to each received packet containing one or more DATA chunk(s)
3110 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3112 if (chunk->end_of_packet) {
3113 /* We must delay the chunk creation since the cumulative
3114 * TSN has not been updated yet.
3116 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3117 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3118 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3119 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3123 return SCTP_DISPOSITION_CONSUME;
3127 * Section: 6.2 Processing a Received SACK
3128 * D) Any time a SACK arrives, the endpoint performs the following:
3130 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3131 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3132 * increasing, a SACK whose Cumulative TSN Ack is less than the
3133 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3135 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3136 * of bytes still outstanding after processing the Cumulative TSN Ack
3137 * and the Gap Ack Blocks.
3139 * iii) If the SACK is missing a TSN that was previously
3140 * acknowledged via a Gap Ack Block (e.g., the data receiver
3141 * reneged on the data), then mark the corresponding DATA chunk
3142 * as available for retransmit: Mark it as missing for fast
3143 * retransmit as described in Section 7.2.4 and if no retransmit
3144 * timer is running for the destination address to which the DATA
3145 * chunk was originally transmitted, then T3-rtx is started for
3146 * that destination address.
3148 * Verification Tag: 8.5 Verification Tag [Normal verification]
3151 * (endpoint, asoc, chunk)
3154 * (asoc, reply_msg, msg_up, timers, counters)
3156 * The return value is the disposition of the chunk.
3158 sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3159 const struct sctp_endpoint *ep,
3160 const struct sctp_association *asoc,
3161 const sctp_subtype_t type,
3163 sctp_cmd_seq_t *commands)
3165 struct sctp_chunk *chunk = arg;
3166 sctp_sackhdr_t *sackh;
3169 if (!sctp_vtag_verify(chunk, asoc))
3170 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3172 /* Make sure that the SACK chunk has a valid length. */
3173 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3174 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3177 /* Pull the SACK chunk from the data buffer */
3178 sackh = sctp_sm_pull_sack(chunk);
3179 /* Was this a bogus SACK? */
3181 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3182 chunk->subh.sack_hdr = sackh;
3183 ctsn = ntohl(sackh->cum_tsn_ack);
3185 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3186 * Ack Point, then drop the SACK. Since Cumulative TSN
3187 * Ack is monotonically increasing, a SACK whose
3188 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3189 * Point indicates an out-of-order SACK.
3191 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3192 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3193 asoc->ctsn_ack_point);
3195 return SCTP_DISPOSITION_DISCARD;
3198 /* If Cumulative TSN Ack beyond the max tsn currently
3199 * send, terminating the association and respond to the
3200 * sender with an ABORT.
3202 if (!TSN_lt(ctsn, asoc->next_tsn))
3203 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3205 /* Return this SACK for further processing. */
3206 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3208 /* Note: We do the rest of the work on the PROCESS_SACK
3211 return SCTP_DISPOSITION_CONSUME;
3215 * Generate an ABORT in response to a packet.
3217 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3219 * 8) The receiver should respond to the sender of the OOTB packet with
3220 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3221 * MUST fill in the Verification Tag field of the outbound packet
3222 * with the value found in the Verification Tag field of the OOTB
3223 * packet and set the T-bit in the Chunk Flags to indicate that the
3224 * Verification Tag is reflected. After sending this ABORT, the
3225 * receiver of the OOTB packet shall discard the OOTB packet and take
3226 * no further action.
3230 * The return value is the disposition of the chunk.
3232 static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3233 const struct sctp_endpoint *ep,
3234 const struct sctp_association *asoc,
3235 const sctp_subtype_t type,
3237 sctp_cmd_seq_t *commands)
3239 struct sctp_packet *packet = NULL;
3240 struct sctp_chunk *chunk = arg;
3241 struct sctp_chunk *abort;
3243 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3246 /* Make an ABORT. The T bit will be set if the asoc
3249 abort = sctp_make_abort(asoc, chunk, 0);
3251 sctp_ootb_pkt_free(packet);
3252 return SCTP_DISPOSITION_NOMEM;
3255 /* Reflect vtag if T-Bit is set */
3256 if (sctp_test_T_bit(abort))
3257 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3259 /* Set the skb to the belonging sock for accounting. */
3260 abort->skb->sk = ep->base.sk;
3262 sctp_packet_append_chunk(packet, abort);
3264 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3265 SCTP_PACKET(packet));
3267 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3269 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3270 return SCTP_DISPOSITION_CONSUME;
3273 return SCTP_DISPOSITION_NOMEM;
3277 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3278 * event as ULP notification for each cause included in the chunk.
3280 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3282 * The return value is the disposition of the chunk.
3284 sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3285 const struct sctp_endpoint *ep,
3286 const struct sctp_association *asoc,
3287 const sctp_subtype_t type,
3289 sctp_cmd_seq_t *commands)
3291 struct sctp_chunk *chunk = arg;
3294 if (!sctp_vtag_verify(chunk, asoc))
3295 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3297 /* Make sure that the ERROR chunk has a valid length. */
3298 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3299 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3301 sctp_walk_errors(err, chunk->chunk_hdr);
3302 if ((void *)err != (void *)chunk->chunk_end)
3303 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3304 (void *)err, commands);
3306 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3309 return SCTP_DISPOSITION_CONSUME;
3313 * Process an inbound SHUTDOWN ACK.
3316 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3317 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3318 * peer, and remove all record of the association.
3320 * The return value is the disposition.
3322 sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3323 const struct sctp_endpoint *ep,
3324 const struct sctp_association *asoc,
3325 const sctp_subtype_t type,
3327 sctp_cmd_seq_t *commands)
3329 struct sctp_chunk *chunk = arg;
3330 struct sctp_chunk *reply;
3331 struct sctp_ulpevent *ev;
3333 if (!sctp_vtag_verify(chunk, asoc))
3334 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3336 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3337 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3338 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3340 /* 10.2 H) SHUTDOWN COMPLETE notification
3342 * When SCTP completes the shutdown procedures (section 9.2) this
3343 * notification is passed to the upper layer.
3345 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3346 0, 0, 0, NULL, GFP_ATOMIC);
3350 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3351 reply = sctp_make_shutdown_complete(asoc, chunk);
3355 /* Do all the commands now (after allocation), so that we
3356 * have consistent state if memory allocation failes
3358 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3360 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3361 * stop the T2-shutdown timer,
3363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3364 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3366 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3367 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3369 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3370 SCTP_STATE(SCTP_STATE_CLOSED));
3371 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3372 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3373 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3375 /* ...and remove all record of the association. */
3376 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3377 return SCTP_DISPOSITION_DELETE_TCB;
3380 sctp_ulpevent_free(ev);
3382 return SCTP_DISPOSITION_NOMEM;
3386 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3388 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3389 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3390 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3391 * packet must fill in the Verification Tag field of the outbound
3392 * packet with the Verification Tag received in the SHUTDOWN ACK and
3393 * set the T-bit in the Chunk Flags to indicate that the Verification
3396 * 8) The receiver should respond to the sender of the OOTB packet with
3397 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3398 * MUST fill in the Verification Tag field of the outbound packet
3399 * with the value found in the Verification Tag field of the OOTB
3400 * packet and set the T-bit in the Chunk Flags to indicate that the
3401 * Verification Tag is reflected. After sending this ABORT, the
3402 * receiver of the OOTB packet shall discard the OOTB packet and take
3403 * no further action.
3405 sctp_disposition_t sctp_sf_ootb(struct net *net,
3406 const struct sctp_endpoint *ep,
3407 const struct sctp_association *asoc,
3408 const sctp_subtype_t type,
3410 sctp_cmd_seq_t *commands)
3412 struct sctp_chunk *chunk = arg;
3413 struct sk_buff *skb = chunk->skb;
3414 sctp_chunkhdr_t *ch;
3417 int ootb_shut_ack = 0;
3418 int ootb_cookie_ack = 0;
3420 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3422 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3424 /* Report violation if the chunk is less then minimal */
3425 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3426 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3429 /* Now that we know we at least have a chunk header,
3430 * do things that are type appropriate.
3432 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3435 /* RFC 2960, Section 3.3.7
3436 * Moreover, under any circumstances, an endpoint that
3437 * receives an ABORT MUST NOT respond to that ABORT by
3438 * sending an ABORT of its own.
3440 if (SCTP_CID_ABORT == ch->type)
3441 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3443 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3444 * or a COOKIE ACK the SCTP Packet should be silently
3448 if (SCTP_CID_COOKIE_ACK == ch->type)
3449 ootb_cookie_ack = 1;
3451 if (SCTP_CID_ERROR == ch->type) {
3452 sctp_walk_errors(err, ch) {
3453 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3454 ootb_cookie_ack = 1;
3460 /* Report violation if chunk len overflows */
3461 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3462 if (ch_end > skb_tail_pointer(skb))
3463 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3466 ch = (sctp_chunkhdr_t *) ch_end;
3467 } while (ch_end < skb_tail_pointer(skb));
3470 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3471 else if (ootb_cookie_ack)
3472 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3474 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3478 * Handle an "Out of the blue" SHUTDOWN ACK.
3480 * Section: 8.4 5, sctpimpguide 2.41.
3482 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3483 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3484 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3485 * packet must fill in the Verification Tag field of the outbound
3486 * packet with the Verification Tag received in the SHUTDOWN ACK and
3487 * set the T-bit in the Chunk Flags to indicate that the Verification
3491 * (endpoint, asoc, type, arg, commands)
3494 * (sctp_disposition_t)
3496 * The return value is the disposition of the chunk.
3498 static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3499 const struct sctp_endpoint *ep,
3500 const struct sctp_association *asoc,
3501 const sctp_subtype_t type,
3503 sctp_cmd_seq_t *commands)
3505 struct sctp_packet *packet = NULL;
3506 struct sctp_chunk *chunk = arg;
3507 struct sctp_chunk *shut;
3509 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3512 /* Make an SHUTDOWN_COMPLETE.
3513 * The T bit will be set if the asoc is NULL.
3515 shut = sctp_make_shutdown_complete(asoc, chunk);
3517 sctp_ootb_pkt_free(packet);
3518 return SCTP_DISPOSITION_NOMEM;
3521 /* Reflect vtag if T-Bit is set */
3522 if (sctp_test_T_bit(shut))
3523 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3525 /* Set the skb to the belonging sock for accounting. */
3526 shut->skb->sk = ep->base.sk;
3528 sctp_packet_append_chunk(packet, shut);
3530 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3531 SCTP_PACKET(packet));
3533 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3535 /* If the chunk length is invalid, we don't want to process
3536 * the reset of the packet.
3538 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3539 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3541 /* We need to discard the rest of the packet to prevent
3542 * potential bomming attacks from additional bundled chunks.
3543 * This is documented in SCTP Threats ID.
3545 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3548 return SCTP_DISPOSITION_NOMEM;
3552 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3554 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3555 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3556 * procedures in section 8.4 SHOULD be followed, in other words it
3557 * should be treated as an Out Of The Blue packet.
3558 * [This means that we do NOT check the Verification Tag on these
3562 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3563 const struct sctp_endpoint *ep,
3564 const struct sctp_association *asoc,
3565 const sctp_subtype_t type,
3567 sctp_cmd_seq_t *commands)
3569 struct sctp_chunk *chunk = arg;
3571 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3572 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3573 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3576 /* Although we do have an association in this case, it corresponds
3577 * to a restarted association. So the packet is treated as an OOTB
3578 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3579 * called with a NULL association.
3581 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3583 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3586 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3587 sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3588 const struct sctp_endpoint *ep,
3589 const struct sctp_association *asoc,
3590 const sctp_subtype_t type, void *arg,
3591 sctp_cmd_seq_t *commands)
3593 struct sctp_chunk *chunk = arg;
3594 struct sctp_chunk *asconf_ack = NULL;
3595 struct sctp_paramhdr *err_param = NULL;
3596 sctp_addiphdr_t *hdr;
3599 if (!sctp_vtag_verify(chunk, asoc)) {
3600 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3602 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3605 /* ADD-IP: Section 4.1.1
3606 * This chunk MUST be sent in an authenticated way by using
3607 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3608 * is received unauthenticated it MUST be silently discarded as
3609 * described in [I-D.ietf-tsvwg-sctp-auth].
3611 if (!net->sctp.addip_noauth && !chunk->auth)
3612 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3614 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3615 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3616 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3619 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3620 serial = ntohl(hdr->serial);
3622 /* Verify the ASCONF chunk before processing it. */
3623 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
3624 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3625 (void *)err_param, commands);
3627 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3628 * the endpoint stored in a new association variable
3629 * 'Peer-Serial-Number'.
3631 if (serial == asoc->peer.addip_serial + 1) {
3632 /* If this is the first instance of ASCONF in the packet,
3633 * we can clean our old ASCONF-ACKs.
3635 if (!chunk->has_asconf)
3636 sctp_assoc_clean_asconf_ack_cache(asoc);
3638 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3639 * expected, process the ASCONF as described below and after
3640 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3641 * the response packet and cache a copy of it (in the event it
3642 * later needs to be retransmitted).
3644 * Essentially, do V1-V5.
3646 asconf_ack = sctp_process_asconf((struct sctp_association *)
3649 return SCTP_DISPOSITION_NOMEM;
3650 } else if (serial < asoc->peer.addip_serial + 1) {
3652 * If the value found in the Sequence Number is less than the
3653 * ('Peer- Sequence-Number' + 1), simply skip to the next
3654 * ASCONF, and include in the outbound response packet
3655 * any previously cached ASCONF-ACK response that was
3656 * sent and saved that matches the Sequence Number of the
3657 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3658 * Chunk exists. This will occur when an older ASCONF
3659 * arrives out of order. In such a case, the receiver
3660 * should skip the ASCONF Chunk and not include ASCONF-ACK
3661 * Chunk for that chunk.
3663 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3665 return SCTP_DISPOSITION_DISCARD;
3667 /* Reset the transport so that we select the correct one
3668 * this time around. This is to make sure that we don't
3669 * accidentally use a stale transport that's been removed.
3671 asconf_ack->transport = NULL;
3673 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3674 * it must be either a stale packet or from an attacker.
3676 return SCTP_DISPOSITION_DISCARD;
3679 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3680 * containing the ASCONF-ACK Chunks MUST be the source address of
3681 * the SCTP packet that held the ASCONF Chunks.
3683 * To do this properly, we'll set the destination address of the chunk
3684 * and at the transmit time, will try look up the transport to use.
3685 * Since ASCONFs may be bundled, the correct transport may not be
3686 * created until we process the entire packet, thus this workaround.
3688 asconf_ack->dest = chunk->source;
3689 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3690 if (asoc->new_transport) {
3691 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3692 ((struct sctp_association *)asoc)->new_transport = NULL;
3695 return SCTP_DISPOSITION_CONSUME;
3699 * ADDIP Section 4.3 General rules for address manipulation
3700 * When building TLV parameters for the ASCONF Chunk that will add or
3701 * delete IP addresses the D0 to D13 rules should be applied:
3703 sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3704 const struct sctp_endpoint *ep,
3705 const struct sctp_association *asoc,
3706 const sctp_subtype_t type, void *arg,
3707 sctp_cmd_seq_t *commands)
3709 struct sctp_chunk *asconf_ack = arg;
3710 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3711 struct sctp_chunk *abort;
3712 struct sctp_paramhdr *err_param = NULL;
3713 sctp_addiphdr_t *addip_hdr;
3714 __u32 sent_serial, rcvd_serial;
3716 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3717 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3719 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3722 /* ADD-IP, Section 4.1.2:
3723 * This chunk MUST be sent in an authenticated way by using
3724 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3725 * is received unauthenticated it MUST be silently discarded as
3726 * described in [I-D.ietf-tsvwg-sctp-auth].
3728 if (!net->sctp.addip_noauth && !asconf_ack->auth)
3729 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
3731 /* Make sure that the ADDIP chunk has a valid length. */
3732 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3733 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3736 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3737 rcvd_serial = ntohl(addip_hdr->serial);
3739 /* Verify the ASCONF-ACK chunk before processing it. */
3740 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
3741 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3742 (void *)err_param, commands);
3745 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3746 sent_serial = ntohl(addip_hdr->serial);
3748 sent_serial = asoc->addip_serial - 1;
3751 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3752 * equal to the next serial number to be used but no ASCONF chunk is
3753 * outstanding the endpoint MUST ABORT the association. Note that a
3754 * sequence number is greater than if it is no more than 2^^31-1
3755 * larger than the current sequence number (using serial arithmetic).
3757 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3758 !(asoc->addip_last_asconf)) {
3759 abort = sctp_make_abort(asoc, asconf_ack,
3760 sizeof(sctp_errhdr_t));
3762 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3763 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3766 /* We are going to ABORT, so we might as well stop
3767 * processing the rest of the chunks in the packet.
3769 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3770 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3771 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3772 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3773 SCTP_ERROR(ECONNABORTED));
3774 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3775 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3776 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3777 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3778 return SCTP_DISPOSITION_ABORT;
3781 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3782 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3783 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3785 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3787 /* Successfully processed ASCONF_ACK. We can
3788 * release the next asconf if we have one.
3790 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3792 return SCTP_DISPOSITION_CONSUME;
3795 abort = sctp_make_abort(asoc, asconf_ack,
3796 sizeof(sctp_errhdr_t));
3798 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3799 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3802 /* We are going to ABORT, so we might as well stop
3803 * processing the rest of the chunks in the packet.
3805 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3806 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3807 SCTP_ERROR(ECONNABORTED));
3808 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3809 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3810 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3811 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3812 return SCTP_DISPOSITION_ABORT;
3815 return SCTP_DISPOSITION_DISCARD;
3819 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3821 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3822 * its cumulative TSN point to the value carried in the FORWARD TSN
3823 * chunk, and then MUST further advance its cumulative TSN point locally
3825 * After the above processing, the data receiver MUST stop reporting any
3826 * missing TSNs earlier than or equal to the new cumulative TSN point.
3828 * Verification Tag: 8.5 Verification Tag [Normal verification]
3830 * The return value is the disposition of the chunk.
3832 sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3833 const struct sctp_endpoint *ep,
3834 const struct sctp_association *asoc,
3835 const sctp_subtype_t type,
3837 sctp_cmd_seq_t *commands)
3839 struct sctp_chunk *chunk = arg;
3840 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3841 struct sctp_fwdtsn_skip *skip;
3845 if (!sctp_vtag_verify(chunk, asoc)) {
3846 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3848 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3851 /* Make sure that the FORWARD_TSN chunk has valid length. */
3852 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3853 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3856 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3857 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3858 len = ntohs(chunk->chunk_hdr->length);
3859 len -= sizeof(struct sctp_chunkhdr);
3860 skb_pull(chunk->skb, len);
3862 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3863 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3865 /* The TSN is too high--silently discard the chunk and count on it
3866 * getting retransmitted later.
3868 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3869 goto discard_noforce;
3871 /* Silently discard the chunk if stream-id is not valid */
3872 sctp_walk_fwdtsn(skip, chunk) {
3873 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3874 goto discard_noforce;
3877 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3878 if (len > sizeof(struct sctp_fwdtsn_hdr))
3879 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3882 /* Count this as receiving DATA. */
3883 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3884 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3885 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3888 /* FIXME: For now send a SACK, but DATA processing may
3891 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3893 return SCTP_DISPOSITION_CONSUME;
3896 return SCTP_DISPOSITION_DISCARD;
3899 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3901 const struct sctp_endpoint *ep,
3902 const struct sctp_association *asoc,
3903 const sctp_subtype_t type,
3905 sctp_cmd_seq_t *commands)
3907 struct sctp_chunk *chunk = arg;
3908 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3909 struct sctp_fwdtsn_skip *skip;
3913 if (!sctp_vtag_verify(chunk, asoc)) {
3914 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3916 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3919 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3920 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3921 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3924 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3925 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3926 len = ntohs(chunk->chunk_hdr->length);
3927 len -= sizeof(struct sctp_chunkhdr);
3928 skb_pull(chunk->skb, len);
3930 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3931 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
3933 /* The TSN is too high--silently discard the chunk and count on it
3934 * getting retransmitted later.
3936 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3939 /* Silently discard the chunk if stream-id is not valid */
3940 sctp_walk_fwdtsn(skip, chunk) {
3941 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3945 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3946 if (len > sizeof(struct sctp_fwdtsn_hdr))
3947 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3950 /* Go a head and force a SACK, since we are shutting down. */
3952 /* Implementor's Guide.
3954 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3955 * respond to each received packet containing one or more DATA chunk(s)
3956 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3958 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3959 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3960 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3961 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3963 return SCTP_DISPOSITION_CONSUME;
3967 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3969 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3970 * Identifier field. If this algorithm was not specified by the
3971 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3972 * during association setup, the AUTH chunk and all chunks after it MUST
3973 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3974 * defined in Section 4.1.
3976 * If an endpoint with no shared key receives a Shared Key Identifier
3977 * other than 0, it MUST silently discard all authenticated chunks. If
3978 * the endpoint has at least one endpoint pair shared key for the peer,
3979 * it MUST use the key specified by the Shared Key Identifier if a
3980 * key has been configured for that Shared Key Identifier. If no
3981 * endpoint pair shared key has been configured for that Shared Key
3982 * Identifier, all authenticated chunks MUST be silently discarded.
3984 * Verification Tag: 8.5 Verification Tag [Normal verification]
3986 * The return value is the disposition of the chunk.
3988 static sctp_ierror_t sctp_sf_authenticate(struct net *net,
3989 const struct sctp_endpoint *ep,
3990 const struct sctp_association *asoc,
3991 const sctp_subtype_t type,
3992 struct sctp_chunk *chunk)
3994 struct sctp_authhdr *auth_hdr;
3995 struct sctp_hmac *hmac;
3996 unsigned int sig_len;
4001 /* Pull in the auth header, so we can do some more verification */
4002 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4003 chunk->subh.auth_hdr = auth_hdr;
4004 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4006 /* Make sure that we support the HMAC algorithm from the auth
4009 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4010 return SCTP_IERROR_AUTH_BAD_HMAC;
4012 /* Make sure that the provided shared key identifier has been
4015 key_id = ntohs(auth_hdr->shkey_id);
4016 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4017 return SCTP_IERROR_AUTH_BAD_KEYID;
4020 /* Make sure that the length of the signature matches what
4023 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4024 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4025 if (sig_len != hmac->hmac_len)
4026 return SCTP_IERROR_PROTO_VIOLATION;
4028 /* Now that we've done validation checks, we can compute and
4029 * verify the hmac. The steps involved are:
4030 * 1. Save the digest from the chunk.
4031 * 2. Zero out the digest in the chunk.
4032 * 3. Compute the new digest
4033 * 4. Compare saved and new digests.
4035 digest = auth_hdr->hmac;
4036 skb_pull(chunk->skb, sig_len);
4038 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4042 memset(digest, 0, sig_len);
4044 sctp_auth_calculate_hmac(asoc, chunk->skb,
4045 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4048 /* Discard the packet if the digests do not match */
4049 if (memcmp(save_digest, digest, sig_len)) {
4051 return SCTP_IERROR_BAD_SIG;
4057 return SCTP_IERROR_NO_ERROR;
4059 return SCTP_IERROR_NOMEM;
4062 sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4063 const struct sctp_endpoint *ep,
4064 const struct sctp_association *asoc,
4065 const sctp_subtype_t type,
4067 sctp_cmd_seq_t *commands)
4069 struct sctp_authhdr *auth_hdr;
4070 struct sctp_chunk *chunk = arg;
4071 struct sctp_chunk *err_chunk;
4072 sctp_ierror_t error;
4074 /* Make sure that the peer has AUTH capable */
4075 if (!asoc->peer.auth_capable)
4076 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4078 if (!sctp_vtag_verify(chunk, asoc)) {
4079 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4081 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4084 /* Make sure that the AUTH chunk has valid length. */
4085 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4086 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4089 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4090 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
4092 case SCTP_IERROR_AUTH_BAD_HMAC:
4093 /* Generate the ERROR chunk and discard the rest
4096 err_chunk = sctp_make_op_error(asoc, chunk,
4097 SCTP_ERROR_UNSUP_HMAC,
4101 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4102 SCTP_CHUNK(err_chunk));
4105 case SCTP_IERROR_AUTH_BAD_KEYID:
4106 case SCTP_IERROR_BAD_SIG:
4107 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4109 case SCTP_IERROR_PROTO_VIOLATION:
4110 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4113 case SCTP_IERROR_NOMEM:
4114 return SCTP_DISPOSITION_NOMEM;
4116 default: /* Prevent gcc warnings */
4120 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4121 struct sctp_ulpevent *ev;
4123 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4124 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4129 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4133 return SCTP_DISPOSITION_CONSUME;
4137 * Process an unknown chunk.
4139 * Section: 3.2. Also, 2.1 in the implementor's guide.
4141 * Chunk Types are encoded such that the highest-order two bits specify
4142 * the action that must be taken if the processing endpoint does not
4143 * recognize the Chunk Type.
4145 * 00 - Stop processing this SCTP packet and discard it, do not process
4146 * any further chunks within it.
4148 * 01 - Stop processing this SCTP packet and discard it, do not process
4149 * any further chunks within it, and report the unrecognized
4150 * chunk in an 'Unrecognized Chunk Type'.
4152 * 10 - Skip this chunk and continue processing.
4154 * 11 - Skip this chunk and continue processing, but report in an ERROR
4155 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4157 * The return value is the disposition of the chunk.
4159 sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4160 const struct sctp_endpoint *ep,
4161 const struct sctp_association *asoc,
4162 const sctp_subtype_t type,
4164 sctp_cmd_seq_t *commands)
4166 struct sctp_chunk *unk_chunk = arg;
4167 struct sctp_chunk *err_chunk;
4168 sctp_chunkhdr_t *hdr;
4170 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4172 if (!sctp_vtag_verify(unk_chunk, asoc))
4173 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4175 /* Make sure that the chunk has a valid length.
4176 * Since we don't know the chunk type, we use a general
4177 * chunkhdr structure to make a comparison.
4179 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4180 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4183 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4184 case SCTP_CID_ACTION_DISCARD:
4185 /* Discard the packet. */
4186 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4187 case SCTP_CID_ACTION_DISCARD_ERR:
4188 /* Generate an ERROR chunk as response. */
4189 hdr = unk_chunk->chunk_hdr;
4190 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4191 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4192 WORD_ROUND(ntohs(hdr->length)),
4195 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4196 SCTP_CHUNK(err_chunk));
4199 /* Discard the packet. */
4200 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4201 return SCTP_DISPOSITION_CONSUME;
4202 case SCTP_CID_ACTION_SKIP:
4203 /* Skip the chunk. */
4204 return SCTP_DISPOSITION_DISCARD;
4205 case SCTP_CID_ACTION_SKIP_ERR:
4206 /* Generate an ERROR chunk as response. */
4207 hdr = unk_chunk->chunk_hdr;
4208 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4209 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4210 WORD_ROUND(ntohs(hdr->length)),
4213 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4214 SCTP_CHUNK(err_chunk));
4216 /* Skip the chunk. */
4217 return SCTP_DISPOSITION_CONSUME;
4222 return SCTP_DISPOSITION_DISCARD;
4226 * Discard the chunk.
4228 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4229 * [Too numerous to mention...]
4230 * Verification Tag: No verification needed.
4232 * (endpoint, asoc, chunk)
4235 * (asoc, reply_msg, msg_up, timers, counters)
4237 * The return value is the disposition of the chunk.
4239 sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4240 const struct sctp_endpoint *ep,
4241 const struct sctp_association *asoc,
4242 const sctp_subtype_t type,
4244 sctp_cmd_seq_t *commands)
4246 struct sctp_chunk *chunk = arg;
4248 /* Make sure that the chunk has a valid length.
4249 * Since we don't know the chunk type, we use a general
4250 * chunkhdr structure to make a comparison.
4252 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4253 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4256 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4258 return SCTP_DISPOSITION_DISCARD;
4262 * Discard the whole packet.
4266 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4267 * silently discard the OOTB packet and take no further action.
4269 * Verification Tag: No verification necessary
4272 * (endpoint, asoc, chunk)
4275 * (asoc, reply_msg, msg_up, timers, counters)
4277 * The return value is the disposition of the chunk.
4279 sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4280 const struct sctp_endpoint *ep,
4281 const struct sctp_association *asoc,
4282 const sctp_subtype_t type,
4284 sctp_cmd_seq_t *commands)
4286 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4287 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4289 return SCTP_DISPOSITION_CONSUME;
4294 * The other end is violating protocol.
4296 * Section: Not specified
4297 * Verification Tag: Not specified
4299 * (endpoint, asoc, chunk)
4302 * (asoc, reply_msg, msg_up, timers, counters)
4304 * We simply tag the chunk as a violation. The state machine will log
4305 * the violation and continue.
4307 sctp_disposition_t sctp_sf_violation(struct net *net,
4308 const struct sctp_endpoint *ep,
4309 const struct sctp_association *asoc,
4310 const sctp_subtype_t type,
4312 sctp_cmd_seq_t *commands)
4314 struct sctp_chunk *chunk = arg;
4316 /* Make sure that the chunk has a valid length. */
4317 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4318 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4321 return SCTP_DISPOSITION_VIOLATION;
4325 * Common function to handle a protocol violation.
4327 static sctp_disposition_t sctp_sf_abort_violation(
4329 const struct sctp_endpoint *ep,
4330 const struct sctp_association *asoc,
4332 sctp_cmd_seq_t *commands,
4333 const __u8 *payload,
4334 const size_t paylen)
4336 struct sctp_packet *packet = NULL;
4337 struct sctp_chunk *chunk = arg;
4338 struct sctp_chunk *abort = NULL;
4340 /* SCTP-AUTH, Section 6.3:
4341 * It should be noted that if the receiver wants to tear
4342 * down an association in an authenticated way only, the
4343 * handling of malformed packets should not result in
4344 * tearing down the association.
4346 * This means that if we only want to abort associations
4347 * in an authenticated way (i.e AUTH+ABORT), then we
4348 * can't destroy this association just because the packet
4351 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4354 /* Make the abort chunk. */
4355 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4360 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4361 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4362 !asoc->peer.i.init_tag) {
4363 sctp_initack_chunk_t *initack;
4365 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4366 if (!sctp_chunk_length_valid(chunk,
4367 sizeof(sctp_initack_chunk_t)))
4368 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4370 unsigned int inittag;
4372 inittag = ntohl(initack->init_hdr.init_tag);
4373 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4378 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4379 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4381 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4382 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4383 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4384 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4385 SCTP_ERROR(ECONNREFUSED));
4386 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4387 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4389 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4390 SCTP_ERROR(ECONNABORTED));
4391 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4392 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4393 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4396 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4401 if (sctp_test_T_bit(abort))
4402 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4404 abort->skb->sk = ep->base.sk;
4406 sctp_packet_append_chunk(packet, abort);
4408 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4409 SCTP_PACKET(packet));
4411 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4414 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4417 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4418 return SCTP_DISPOSITION_ABORT;
4421 sctp_chunk_free(abort);
4423 return SCTP_DISPOSITION_NOMEM;
4427 * Handle a protocol violation when the chunk length is invalid.
4428 * "Invalid" length is identified as smaller than the minimal length a
4429 * given chunk can be. For example, a SACK chunk has invalid length
4430 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4432 * We inform the other end by sending an ABORT with a Protocol Violation
4435 * Section: Not specified
4436 * Verification Tag: Nothing to do
4438 * (endpoint, asoc, chunk)
4441 * (reply_msg, msg_up, counters)
4443 * Generate an ABORT chunk and terminate the association.
4445 static sctp_disposition_t sctp_sf_violation_chunklen(
4447 const struct sctp_endpoint *ep,
4448 const struct sctp_association *asoc,
4449 const sctp_subtype_t type,
4451 sctp_cmd_seq_t *commands)
4453 static const char err_str[] = "The following chunk had invalid length:";
4455 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4460 * Handle a protocol violation when the parameter length is invalid.
4461 * If the length is smaller than the minimum length of a given parameter,
4462 * or accumulated length in multi parameters exceeds the end of the chunk,
4463 * the length is considered as invalid.
4465 static sctp_disposition_t sctp_sf_violation_paramlen(
4467 const struct sctp_endpoint *ep,
4468 const struct sctp_association *asoc,
4469 const sctp_subtype_t type,
4470 void *arg, void *ext,
4471 sctp_cmd_seq_t *commands)
4473 struct sctp_chunk *chunk = arg;
4474 struct sctp_paramhdr *param = ext;
4475 struct sctp_chunk *abort = NULL;
4477 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4480 /* Make the abort chunk. */
4481 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4485 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4486 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4488 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4489 SCTP_ERROR(ECONNABORTED));
4490 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4491 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4492 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4493 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4496 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4497 return SCTP_DISPOSITION_ABORT;
4499 return SCTP_DISPOSITION_NOMEM;
4502 /* Handle a protocol violation when the peer trying to advance the
4503 * cumulative tsn ack to a point beyond the max tsn currently sent.
4505 * We inform the other end by sending an ABORT with a Protocol Violation
4508 static sctp_disposition_t sctp_sf_violation_ctsn(
4510 const struct sctp_endpoint *ep,
4511 const struct sctp_association *asoc,
4512 const sctp_subtype_t type,
4514 sctp_cmd_seq_t *commands)
4516 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4518 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4522 /* Handle protocol violation of an invalid chunk bundling. For example,
4523 * when we have an association and we receive bundled INIT-ACK, or
4524 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4525 * statement from the specs. Additionally, there might be an attacker
4526 * on the path and we may not want to continue this communication.
4528 static sctp_disposition_t sctp_sf_violation_chunk(
4530 const struct sctp_endpoint *ep,
4531 const struct sctp_association *asoc,
4532 const sctp_subtype_t type,
4534 sctp_cmd_seq_t *commands)
4536 static const char err_str[] = "The following chunk violates protocol:";
4539 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
4541 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4544 /***************************************************************************
4545 * These are the state functions for handling primitive (Section 10) events.
4546 ***************************************************************************/
4548 * sctp_sf_do_prm_asoc
4550 * Section: 10.1 ULP-to-SCTP
4553 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4554 * outbound stream count)
4555 * -> association id [,destination transport addr list] [,outbound stream
4558 * This primitive allows the upper layer to initiate an association to a
4559 * specific peer endpoint.
4561 * The peer endpoint shall be specified by one of the transport addresses
4562 * which defines the endpoint (see Section 1.4). If the local SCTP
4563 * instance has not been initialized, the ASSOCIATE is considered an
4565 * [This is not relevant for the kernel implementation since we do all
4566 * initialization at boot time. It we hadn't initialized we wouldn't
4567 * get anywhere near this code.]
4569 * An association id, which is a local handle to the SCTP association,
4570 * will be returned on successful establishment of the association. If
4571 * SCTP is not able to open an SCTP association with the peer endpoint,
4572 * an error is returned.
4573 * [In the kernel implementation, the struct sctp_association needs to
4574 * be created BEFORE causing this primitive to run.]
4576 * Other association parameters may be returned, including the
4577 * complete destination transport addresses of the peer as well as the
4578 * outbound stream count of the local endpoint. One of the transport
4579 * address from the returned destination addresses will be selected by
4580 * the local endpoint as default primary path for sending SCTP packets
4581 * to this peer. The returned "destination transport addr list" can
4582 * be used by the ULP to change the default primary path or to force
4583 * sending a packet to a specific transport address. [All of this
4584 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4587 * Mandatory attributes:
4589 * o local SCTP instance name - obtained from the INITIALIZE operation.
4590 * [This is the argument asoc.]
4591 * o destination transport addr - specified as one of the transport
4592 * addresses of the peer endpoint with which the association is to be
4594 * [This is asoc->peer.active_path.]
4595 * o outbound stream count - the number of outbound streams the ULP
4596 * would like to open towards this peer endpoint.
4597 * [BUG: This is not currently implemented.]
4598 * Optional attributes:
4602 * The return value is a disposition.
4604 sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4605 const struct sctp_endpoint *ep,
4606 const struct sctp_association *asoc,
4607 const sctp_subtype_t type,
4609 sctp_cmd_seq_t *commands)
4611 struct sctp_chunk *repl;
4612 struct sctp_association *my_asoc;
4614 /* The comment below says that we enter COOKIE-WAIT AFTER
4615 * sending the INIT, but that doesn't actually work in our
4618 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4619 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4621 /* RFC 2960 5.1 Normal Establishment of an Association
4623 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4624 * must provide its Verification Tag (Tag_A) in the Initiate
4625 * Tag field. Tag_A SHOULD be a random number in the range of
4626 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4629 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4633 /* Choose transport for INIT. */
4634 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4637 /* Cast away the const modifier, as we want to just
4638 * rerun it through as a sideffect.
4640 my_asoc = (struct sctp_association *)asoc;
4641 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4643 /* After sending the INIT, "A" starts the T1-init timer and
4644 * enters the COOKIE-WAIT state.
4646 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4647 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4648 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4649 return SCTP_DISPOSITION_CONSUME;
4652 return SCTP_DISPOSITION_NOMEM;
4656 * Process the SEND primitive.
4658 * Section: 10.1 ULP-to-SCTP
4661 * Format: SEND(association id, buffer address, byte count [,context]
4662 * [,stream id] [,life time] [,destination transport address]
4663 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4666 * This is the main method to send user data via SCTP.
4668 * Mandatory attributes:
4670 * o association id - local handle to the SCTP association
4672 * o buffer address - the location where the user message to be
4673 * transmitted is stored;
4675 * o byte count - The size of the user data in number of bytes;
4677 * Optional attributes:
4679 * o context - an optional 32 bit integer that will be carried in the
4680 * sending failure notification to the ULP if the transportation of
4681 * this User Message fails.
4683 * o stream id - to indicate which stream to send the data on. If not
4684 * specified, stream 0 will be used.
4686 * o life time - specifies the life time of the user data. The user data
4687 * will not be sent by SCTP after the life time expires. This
4688 * parameter can be used to avoid efforts to transmit stale
4689 * user messages. SCTP notifies the ULP if the data cannot be
4690 * initiated to transport (i.e. sent to the destination via SCTP's
4691 * send primitive) within the life time variable. However, the
4692 * user data will be transmitted if SCTP has attempted to transmit a
4693 * chunk before the life time expired.
4695 * o destination transport address - specified as one of the destination
4696 * transport addresses of the peer endpoint to which this packet
4697 * should be sent. Whenever possible, SCTP should use this destination
4698 * transport address for sending the packets, instead of the current
4701 * o unorder flag - this flag, if present, indicates that the user
4702 * would like the data delivered in an unordered fashion to the peer
4703 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4706 * o no-bundle flag - instructs SCTP not to bundle this user data with
4707 * other outbound DATA chunks. SCTP MAY still bundle even when
4708 * this flag is present, when faced with network congestion.
4710 * o payload protocol-id - A 32 bit unsigned integer that is to be
4711 * passed to the peer indicating the type of payload protocol data
4712 * being transmitted. This value is passed as opaque data by SCTP.
4714 * The return value is the disposition.
4716 sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4717 const struct sctp_endpoint *ep,
4718 const struct sctp_association *asoc,
4719 const sctp_subtype_t type,
4721 sctp_cmd_seq_t *commands)
4723 struct sctp_datamsg *msg = arg;
4725 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4726 return SCTP_DISPOSITION_CONSUME;
4730 * Process the SHUTDOWN primitive.
4735 * Format: SHUTDOWN(association id)
4738 * Gracefully closes an association. Any locally queued user data
4739 * will be delivered to the peer. The association will be terminated only
4740 * after the peer acknowledges all the SCTP packets sent. A success code
4741 * will be returned on successful termination of the association. If
4742 * attempting to terminate the association results in a failure, an error
4743 * code shall be returned.
4745 * Mandatory attributes:
4747 * o association id - local handle to the SCTP association
4749 * Optional attributes:
4753 * The return value is the disposition.
4755 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4757 const struct sctp_endpoint *ep,
4758 const struct sctp_association *asoc,
4759 const sctp_subtype_t type,
4761 sctp_cmd_seq_t *commands)
4765 /* From 9.2 Shutdown of an Association
4766 * Upon receipt of the SHUTDOWN primitive from its upper
4767 * layer, the endpoint enters SHUTDOWN-PENDING state and
4768 * remains there until all outstanding data has been
4769 * acknowledged by its peer. The endpoint accepts no new data
4770 * from its upper layer, but retransmits data to the far end
4771 * if necessary to fill gaps.
4773 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4774 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4776 disposition = SCTP_DISPOSITION_CONSUME;
4777 if (sctp_outq_is_empty(&asoc->outqueue)) {
4778 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
4785 * Process the ABORT primitive.
4790 * Format: Abort(association id [, cause code])
4793 * Ungracefully closes an association. Any locally queued user data
4794 * will be discarded and an ABORT chunk is sent to the peer. A success code
4795 * will be returned on successful abortion of the association. If
4796 * attempting to abort the association results in a failure, an error
4797 * code shall be returned.
4799 * Mandatory attributes:
4801 * o association id - local handle to the SCTP association
4803 * Optional attributes:
4805 * o cause code - reason of the abort to be passed to the peer
4809 * The return value is the disposition.
4811 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4813 const struct sctp_endpoint *ep,
4814 const struct sctp_association *asoc,
4815 const sctp_subtype_t type,
4817 sctp_cmd_seq_t *commands)
4819 /* From 9.1 Abort of an Association
4820 * Upon receipt of the ABORT primitive from its upper
4821 * layer, the endpoint enters CLOSED state and
4822 * discard all outstanding data has been
4823 * acknowledged by its peer. The endpoint accepts no new data
4824 * from its upper layer, but retransmits data to the far end
4825 * if necessary to fill gaps.
4827 struct sctp_chunk *abort = arg;
4828 sctp_disposition_t retval;
4830 retval = SCTP_DISPOSITION_CONSUME;
4832 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4834 /* Even if we can't send the ABORT due to low memory delete the
4835 * TCB. This is a departure from our typical NOMEM handling.
4838 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4839 SCTP_ERROR(ECONNABORTED));
4840 /* Delete the established association. */
4841 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4842 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4844 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4845 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4850 /* We tried an illegal operation on an association which is closed. */
4851 sctp_disposition_t sctp_sf_error_closed(struct net *net,
4852 const struct sctp_endpoint *ep,
4853 const struct sctp_association *asoc,
4854 const sctp_subtype_t type,
4856 sctp_cmd_seq_t *commands)
4858 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4859 return SCTP_DISPOSITION_CONSUME;
4862 /* We tried an illegal operation on an association which is shutting
4865 sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4866 const struct sctp_endpoint *ep,
4867 const struct sctp_association *asoc,
4868 const sctp_subtype_t type,
4870 sctp_cmd_seq_t *commands)
4872 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4873 SCTP_ERROR(-ESHUTDOWN));
4874 return SCTP_DISPOSITION_CONSUME;
4878 * sctp_cookie_wait_prm_shutdown
4880 * Section: 4 Note: 2
4885 * The RFC does not explicitly address this issue, but is the route through the
4886 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4891 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4893 const struct sctp_endpoint *ep,
4894 const struct sctp_association *asoc,
4895 const sctp_subtype_t type,
4897 sctp_cmd_seq_t *commands)
4899 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4900 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4902 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4903 SCTP_STATE(SCTP_STATE_CLOSED));
4905 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
4907 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4909 return SCTP_DISPOSITION_DELETE_TCB;
4913 * sctp_cookie_echoed_prm_shutdown
4915 * Section: 4 Note: 2
4920 * The RFC does not explcitly address this issue, but is the route through the
4921 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4926 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4928 const struct sctp_endpoint *ep,
4929 const struct sctp_association *asoc,
4930 const sctp_subtype_t type,
4931 void *arg, sctp_cmd_seq_t *commands)
4933 /* There is a single T1 timer, so we should be able to use
4934 * common function with the COOKIE-WAIT state.
4936 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
4940 * sctp_sf_cookie_wait_prm_abort
4942 * Section: 4 Note: 2
4947 * The RFC does not explicitly address this issue, but is the route through the
4948 * state table when someone issues an abort while in COOKIE_WAIT state.
4953 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4955 const struct sctp_endpoint *ep,
4956 const struct sctp_association *asoc,
4957 const sctp_subtype_t type,
4959 sctp_cmd_seq_t *commands)
4961 struct sctp_chunk *abort = arg;
4962 sctp_disposition_t retval;
4964 /* Stop T1-init timer */
4965 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4966 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4967 retval = SCTP_DISPOSITION_CONSUME;
4969 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4971 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4972 SCTP_STATE(SCTP_STATE_CLOSED));
4974 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4976 /* Even if we can't send the ABORT due to low memory delete the
4977 * TCB. This is a departure from our typical NOMEM handling.
4980 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4981 SCTP_ERROR(ECONNREFUSED));
4982 /* Delete the established association. */
4983 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4984 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4990 * sctp_sf_cookie_echoed_prm_abort
4992 * Section: 4 Note: 3
4997 * The RFC does not explcitly address this issue, but is the route through the
4998 * state table when someone issues an abort while in COOKIE_ECHOED state.
5003 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
5005 const struct sctp_endpoint *ep,
5006 const struct sctp_association *asoc,
5007 const sctp_subtype_t type,
5009 sctp_cmd_seq_t *commands)
5011 /* There is a single T1 timer, so we should be able to use
5012 * common function with the COOKIE-WAIT state.
5014 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5018 * sctp_sf_shutdown_pending_prm_abort
5023 * The RFC does not explicitly address this issue, but is the route through the
5024 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5029 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
5031 const struct sctp_endpoint *ep,
5032 const struct sctp_association *asoc,
5033 const sctp_subtype_t type,
5035 sctp_cmd_seq_t *commands)
5037 /* Stop the T5-shutdown guard timer. */
5038 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5039 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5041 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5045 * sctp_sf_shutdown_sent_prm_abort
5050 * The RFC does not explicitly address this issue, but is the route through the
5051 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5056 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
5058 const struct sctp_endpoint *ep,
5059 const struct sctp_association *asoc,
5060 const sctp_subtype_t type,
5062 sctp_cmd_seq_t *commands)
5064 /* Stop the T2-shutdown timer. */
5065 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5066 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5068 /* Stop the T5-shutdown guard timer. */
5069 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5070 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5072 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5076 * sctp_sf_cookie_echoed_prm_abort
5081 * The RFC does not explcitly address this issue, but is the route through the
5082 * state table when someone issues an abort while in COOKIE_ECHOED state.
5087 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
5089 const struct sctp_endpoint *ep,
5090 const struct sctp_association *asoc,
5091 const sctp_subtype_t type,
5093 sctp_cmd_seq_t *commands)
5095 /* The same T2 timer, so we should be able to use
5096 * common function with the SHUTDOWN-SENT state.
5098 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5102 * Process the REQUESTHEARTBEAT primitive
5105 * J) Request Heartbeat
5107 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5111 * Instructs the local endpoint to perform a HeartBeat on the specified
5112 * destination transport address of the given association. The returned
5113 * result should indicate whether the transmission of the HEARTBEAT
5114 * chunk to the destination address is successful.
5116 * Mandatory attributes:
5118 * o association id - local handle to the SCTP association
5120 * o destination transport address - the transport address of the
5121 * association on which a heartbeat should be issued.
5123 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5125 const struct sctp_endpoint *ep,
5126 const struct sctp_association *asoc,
5127 const sctp_subtype_t type,
5129 sctp_cmd_seq_t *commands)
5131 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5132 (struct sctp_transport *)arg, commands))
5133 return SCTP_DISPOSITION_NOMEM;
5136 * RFC 2960 (bis), section 8.3
5138 * D) Request an on-demand HEARTBEAT on a specific destination
5139 * transport address of a given association.
5141 * The endpoint should increment the respective error counter of
5142 * the destination transport address each time a HEARTBEAT is sent
5143 * to that address and not acknowledged within one RTO.
5146 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5147 SCTP_TRANSPORT(arg));
5148 return SCTP_DISPOSITION_CONSUME;
5152 * ADDIP Section 4.1 ASCONF Chunk Procedures
5153 * When an endpoint has an ASCONF signaled change to be sent to the
5154 * remote endpoint it should do A1 to A9
5156 sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5157 const struct sctp_endpoint *ep,
5158 const struct sctp_association *asoc,
5159 const sctp_subtype_t type,
5161 sctp_cmd_seq_t *commands)
5163 struct sctp_chunk *chunk = arg;
5165 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5166 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5167 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5168 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5169 return SCTP_DISPOSITION_CONSUME;
5173 * Ignore the primitive event
5175 * The return value is the disposition of the primitive.
5177 sctp_disposition_t sctp_sf_ignore_primitive(
5179 const struct sctp_endpoint *ep,
5180 const struct sctp_association *asoc,
5181 const sctp_subtype_t type,
5183 sctp_cmd_seq_t *commands)
5185 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5188 return SCTP_DISPOSITION_DISCARD;
5191 /***************************************************************************
5192 * These are the state functions for the OTHER events.
5193 ***************************************************************************/
5196 * When the SCTP stack has no more user data to send or retransmit, this
5197 * notification is given to the user. Also, at the time when a user app
5198 * subscribes to this event, if there is no data to be sent or
5199 * retransmit, the stack will immediately send up this notification.
5201 sctp_disposition_t sctp_sf_do_no_pending_tsn(
5203 const struct sctp_endpoint *ep,
5204 const struct sctp_association *asoc,
5205 const sctp_subtype_t type,
5207 sctp_cmd_seq_t *commands)
5209 struct sctp_ulpevent *event;
5211 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5213 return SCTP_DISPOSITION_NOMEM;
5215 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5217 return SCTP_DISPOSITION_CONSUME;
5221 * Start the shutdown negotiation.
5224 * Once all its outstanding data has been acknowledged, the endpoint
5225 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5226 * TSN Ack field the last sequential TSN it has received from the peer.
5227 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5228 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5229 * with the updated last sequential TSN received from its peer.
5231 * The return value is the disposition.
5233 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5235 const struct sctp_endpoint *ep,
5236 const struct sctp_association *asoc,
5237 const sctp_subtype_t type,
5239 sctp_cmd_seq_t *commands)
5241 struct sctp_chunk *reply;
5243 /* Once all its outstanding data has been acknowledged, the
5244 * endpoint shall send a SHUTDOWN chunk to its peer including
5245 * in the Cumulative TSN Ack field the last sequential TSN it
5246 * has received from the peer.
5248 reply = sctp_make_shutdown(asoc, NULL);
5252 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5253 * T2-shutdown timer.
5255 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5257 /* It shall then start the T2-shutdown timer */
5258 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5259 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5261 /* RFC 4960 Section 9.2
5262 * The sender of the SHUTDOWN MAY also start an overall guard timer
5263 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5265 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5266 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5268 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5269 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5270 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5272 /* and enter the SHUTDOWN-SENT state. */
5273 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5274 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5276 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5278 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5281 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5283 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5285 return SCTP_DISPOSITION_CONSUME;
5288 return SCTP_DISPOSITION_NOMEM;
5292 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5296 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5297 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5298 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5299 * endpoint must re-send the SHUTDOWN ACK.
5301 * The return value is the disposition.
5303 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5305 const struct sctp_endpoint *ep,
5306 const struct sctp_association *asoc,
5307 const sctp_subtype_t type,
5309 sctp_cmd_seq_t *commands)
5311 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5312 struct sctp_chunk *reply;
5314 /* There are 2 ways of getting here:
5315 * 1) called in response to a SHUTDOWN chunk
5316 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5318 * For the case (2), the arg parameter is set to NULL. We need
5319 * to check that we have a chunk before accessing it's fields.
5322 if (!sctp_vtag_verify(chunk, asoc))
5323 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
5325 /* Make sure that the SHUTDOWN chunk has a valid length. */
5326 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5327 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
5331 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5332 * shall send a SHUTDOWN ACK ...
5334 reply = sctp_make_shutdown_ack(asoc, chunk);
5338 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5339 * the T2-shutdown timer.
5341 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5343 /* and start/restart a T2-shutdown timer of its own, */
5344 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5345 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5347 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5348 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5349 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5351 /* Enter the SHUTDOWN-ACK-SENT state. */
5352 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5353 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5355 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5357 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5360 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5362 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5364 return SCTP_DISPOSITION_CONSUME;
5367 return SCTP_DISPOSITION_NOMEM;
5371 * Ignore the event defined as other
5373 * The return value is the disposition of the event.
5375 sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5376 const struct sctp_endpoint *ep,
5377 const struct sctp_association *asoc,
5378 const sctp_subtype_t type,
5380 sctp_cmd_seq_t *commands)
5382 pr_debug("%s: the event other type:%d is ignored\n",
5383 __func__, type.other);
5385 return SCTP_DISPOSITION_DISCARD;
5388 /************************************************************
5389 * These are the state functions for handling timeout events.
5390 ************************************************************/
5395 * Section: 6.3.3 Handle T3-rtx Expiration
5397 * Whenever the retransmission timer T3-rtx expires for a destination
5398 * address, do the following:
5401 * The return value is the disposition of the chunk.
5403 sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5404 const struct sctp_endpoint *ep,
5405 const struct sctp_association *asoc,
5406 const sctp_subtype_t type,
5408 sctp_cmd_seq_t *commands)
5410 struct sctp_transport *transport = arg;
5412 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5414 if (asoc->overall_error_count >= asoc->max_retrans) {
5415 if (asoc->peer.zero_window_announced &&
5416 asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5418 * We are here likely because the receiver had its rwnd
5419 * closed for a while and we have not been able to
5420 * transmit the locally queued data within the maximum
5421 * retransmission attempts limit. Start the T5
5422 * shutdown guard timer to give the receiver one last
5423 * chance and some additional time to recover before
5426 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5427 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5429 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5430 SCTP_ERROR(ETIMEDOUT));
5431 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5432 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5433 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5434 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5435 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5436 return SCTP_DISPOSITION_DELETE_TCB;
5440 /* E1) For the destination address for which the timer
5441 * expires, adjust its ssthresh with rules defined in Section
5442 * 7.2.3 and set the cwnd <- MTU.
5445 /* E2) For the destination address for which the timer
5446 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5447 * maximum value discussed in rule C7 above (RTO.max) may be
5448 * used to provide an upper bound to this doubling operation.
5451 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5452 * outstanding DATA chunks for the address for which the
5453 * T3-rtx has expired will fit into a single packet, subject
5454 * to the MTU constraint for the path corresponding to the
5455 * destination transport address to which the retransmission
5456 * is being sent (this may be different from the address for
5457 * which the timer expires [see Section 6.4]). Call this
5458 * value K. Bundle and retransmit those K DATA chunks in a
5459 * single packet to the destination endpoint.
5461 * Note: Any DATA chunks that were sent to the address for
5462 * which the T3-rtx timer expired but did not fit in one MTU
5463 * (rule E3 above), should be marked for retransmission and
5464 * sent as soon as cwnd allows (normally when a SACK arrives).
5467 /* Do some failure management (Section 8.2). */
5468 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5470 /* NB: Rules E4 and F1 are implicit in R1. */
5471 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5473 return SCTP_DISPOSITION_CONSUME;
5477 * Generate delayed SACK on timeout
5479 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5481 * The guidelines on delayed acknowledgement algorithm specified in
5482 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5483 * acknowledgement SHOULD be generated for at least every second packet
5484 * (not every second DATA chunk) received, and SHOULD be generated
5485 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5486 * some situations it may be beneficial for an SCTP transmitter to be
5487 * more conservative than the algorithms detailed in this document
5488 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5489 * the following algorithms allow.
5491 sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5492 const struct sctp_endpoint *ep,
5493 const struct sctp_association *asoc,
5494 const sctp_subtype_t type,
5496 sctp_cmd_seq_t *commands)
5498 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5499 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5500 return SCTP_DISPOSITION_CONSUME;
5504 * sctp_sf_t1_init_timer_expire
5506 * Section: 4 Note: 2
5511 * RFC 2960 Section 4 Notes
5512 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5513 * and re-start the T1-init timer without changing state. This MUST
5514 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5515 * endpoint MUST abort the initialization process and report the
5516 * error to SCTP user.
5522 sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5523 const struct sctp_endpoint *ep,
5524 const struct sctp_association *asoc,
5525 const sctp_subtype_t type,
5527 sctp_cmd_seq_t *commands)
5529 struct sctp_chunk *repl = NULL;
5530 struct sctp_bind_addr *bp;
5531 int attempts = asoc->init_err_counter + 1;
5533 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5535 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5537 if (attempts <= asoc->max_init_attempts) {
5538 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5539 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5541 return SCTP_DISPOSITION_NOMEM;
5543 /* Choose transport for INIT. */
5544 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5547 /* Issue a sideeffect to do the needed accounting. */
5548 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5549 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5551 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5553 pr_debug("%s: giving up on INIT, attempts:%d "
5554 "max_init_attempts:%d\n", __func__, attempts,
5555 asoc->max_init_attempts);
5557 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5558 SCTP_ERROR(ETIMEDOUT));
5559 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5560 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5561 return SCTP_DISPOSITION_DELETE_TCB;
5564 return SCTP_DISPOSITION_CONSUME;
5568 * sctp_sf_t1_cookie_timer_expire
5570 * Section: 4 Note: 2
5575 * RFC 2960 Section 4 Notes
5576 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5577 * COOKIE ECHO and re-start the T1-cookie timer without changing
5578 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5579 * After that, the endpoint MUST abort the initialization process and
5580 * report the error to SCTP user.
5586 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5587 const struct sctp_endpoint *ep,
5588 const struct sctp_association *asoc,
5589 const sctp_subtype_t type,
5591 sctp_cmd_seq_t *commands)
5593 struct sctp_chunk *repl = NULL;
5594 int attempts = asoc->init_err_counter + 1;
5596 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5598 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5600 if (attempts <= asoc->max_init_attempts) {
5601 repl = sctp_make_cookie_echo(asoc, NULL);
5603 return SCTP_DISPOSITION_NOMEM;
5605 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5607 /* Issue a sideeffect to do the needed accounting. */
5608 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5609 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5611 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5613 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5614 SCTP_ERROR(ETIMEDOUT));
5615 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5616 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5617 return SCTP_DISPOSITION_DELETE_TCB;
5620 return SCTP_DISPOSITION_CONSUME;
5623 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5624 * with the updated last sequential TSN received from its peer.
5626 * An endpoint should limit the number of retransmissions of the
5627 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5628 * If this threshold is exceeded the endpoint should destroy the TCB and
5629 * MUST report the peer endpoint unreachable to the upper layer (and
5630 * thus the association enters the CLOSED state). The reception of any
5631 * packet from its peer (i.e. as the peer sends all of its queued DATA
5632 * chunks) should clear the endpoint's retransmission count and restart
5633 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5634 * all of its queued DATA chunks that have not yet been sent.
5636 sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5637 const struct sctp_endpoint *ep,
5638 const struct sctp_association *asoc,
5639 const sctp_subtype_t type,
5641 sctp_cmd_seq_t *commands)
5643 struct sctp_chunk *reply = NULL;
5645 pr_debug("%s: timer T2 expired\n", __func__);
5647 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5649 ((struct sctp_association *)asoc)->shutdown_retries++;
5651 if (asoc->overall_error_count >= asoc->max_retrans) {
5652 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5653 SCTP_ERROR(ETIMEDOUT));
5654 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5655 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5656 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5657 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5658 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5659 return SCTP_DISPOSITION_DELETE_TCB;
5662 switch (asoc->state) {
5663 case SCTP_STATE_SHUTDOWN_SENT:
5664 reply = sctp_make_shutdown(asoc, NULL);
5667 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5668 reply = sctp_make_shutdown_ack(asoc, NULL);
5679 /* Do some failure management (Section 8.2).
5680 * If we remove the transport an SHUTDOWN was last sent to, don't
5681 * do failure management.
5683 if (asoc->shutdown_last_sent_to)
5684 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5685 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5687 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5688 * the T2-shutdown timer.
5690 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5692 /* Restart the T2-shutdown timer. */
5693 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5694 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5695 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5696 return SCTP_DISPOSITION_CONSUME;
5699 return SCTP_DISPOSITION_NOMEM;
5703 * ADDIP Section 4.1 ASCONF CHunk Procedures
5704 * If the T4 RTO timer expires the endpoint should do B1 to B5
5706 sctp_disposition_t sctp_sf_t4_timer_expire(
5708 const struct sctp_endpoint *ep,
5709 const struct sctp_association *asoc,
5710 const sctp_subtype_t type,
5712 sctp_cmd_seq_t *commands)
5714 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5715 struct sctp_transport *transport = chunk->transport;
5717 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
5719 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5720 * detection on the appropriate destination address as defined in
5721 * RFC2960 [5] section 8.1 and 8.2.
5724 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5725 SCTP_TRANSPORT(transport));
5727 /* Reconfig T4 timer and transport. */
5728 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5730 /* ADDIP 4.1 B2) Increment the association error counters and perform
5731 * endpoint failure detection on the association as defined in
5732 * RFC2960 [5] section 8.1 and 8.2.
5733 * association error counter is incremented in SCTP_CMD_STRIKE.
5735 if (asoc->overall_error_count >= asoc->max_retrans) {
5736 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5737 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5738 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5739 SCTP_ERROR(ETIMEDOUT));
5740 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5741 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5742 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5743 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5744 return SCTP_DISPOSITION_ABORT;
5747 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5748 * the ASCONF chunk was sent by doubling the RTO timer value.
5749 * This is done in SCTP_CMD_STRIKE.
5752 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5753 * choose an alternate destination address (please refer to RFC2960
5754 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5755 * chunk, it MUST be the same (including its serial number) as the last
5758 sctp_chunk_hold(asoc->addip_last_asconf);
5759 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5760 SCTP_CHUNK(asoc->addip_last_asconf));
5762 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5763 * destination is selected, then the RTO used will be that of the new
5764 * destination address.
5766 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5767 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5769 return SCTP_DISPOSITION_CONSUME;
5772 /* sctpimpguide-05 Section 2.12.2
5773 * The sender of the SHUTDOWN MAY also start an overall guard timer
5774 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5775 * At the expiration of this timer the sender SHOULD abort the association
5776 * by sending an ABORT chunk.
5778 sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5779 const struct sctp_endpoint *ep,
5780 const struct sctp_association *asoc,
5781 const sctp_subtype_t type,
5783 sctp_cmd_seq_t *commands)
5785 struct sctp_chunk *reply = NULL;
5787 pr_debug("%s: timer T5 expired\n", __func__);
5789 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5791 reply = sctp_make_abort(asoc, NULL, 0);
5795 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5796 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5797 SCTP_ERROR(ETIMEDOUT));
5798 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5799 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5801 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5802 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5804 return SCTP_DISPOSITION_DELETE_TCB;
5806 return SCTP_DISPOSITION_NOMEM;
5809 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5810 * the association is automatically closed by starting the shutdown process.
5811 * The work that needs to be done is same as when SHUTDOWN is initiated by
5812 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5814 sctp_disposition_t sctp_sf_autoclose_timer_expire(
5816 const struct sctp_endpoint *ep,
5817 const struct sctp_association *asoc,
5818 const sctp_subtype_t type,
5820 sctp_cmd_seq_t *commands)
5824 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
5826 /* From 9.2 Shutdown of an Association
5827 * Upon receipt of the SHUTDOWN primitive from its upper
5828 * layer, the endpoint enters SHUTDOWN-PENDING state and
5829 * remains there until all outstanding data has been
5830 * acknowledged by its peer. The endpoint accepts no new data
5831 * from its upper layer, but retransmits data to the far end
5832 * if necessary to fill gaps.
5834 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5835 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5837 disposition = SCTP_DISPOSITION_CONSUME;
5838 if (sctp_outq_is_empty(&asoc->outqueue)) {
5839 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
5845 /*****************************************************************************
5846 * These are sa state functions which could apply to all types of events.
5847 ****************************************************************************/
5850 * This table entry is not implemented.
5853 * (endpoint, asoc, chunk)
5855 * The return value is the disposition of the chunk.
5857 sctp_disposition_t sctp_sf_not_impl(struct net *net,
5858 const struct sctp_endpoint *ep,
5859 const struct sctp_association *asoc,
5860 const sctp_subtype_t type,
5862 sctp_cmd_seq_t *commands)
5864 return SCTP_DISPOSITION_NOT_IMPL;
5868 * This table entry represents a bug.
5871 * (endpoint, asoc, chunk)
5873 * The return value is the disposition of the chunk.
5875 sctp_disposition_t sctp_sf_bug(struct net *net,
5876 const struct sctp_endpoint *ep,
5877 const struct sctp_association *asoc,
5878 const sctp_subtype_t type,
5880 sctp_cmd_seq_t *commands)
5882 return SCTP_DISPOSITION_BUG;
5886 * This table entry represents the firing of a timer in the wrong state.
5887 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5888 * when the association is in the wrong state. This event should
5889 * be ignored, so as to prevent any rearming of the timer.
5892 * (endpoint, asoc, chunk)
5894 * The return value is the disposition of the chunk.
5896 sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5897 const struct sctp_endpoint *ep,
5898 const struct sctp_association *asoc,
5899 const sctp_subtype_t type,
5901 sctp_cmd_seq_t *commands)
5903 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
5905 return SCTP_DISPOSITION_CONSUME;
5908 /********************************************************************
5909 * 2nd Level Abstractions
5910 ********************************************************************/
5912 /* Pull the SACK chunk based on the SACK header. */
5913 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5915 struct sctp_sackhdr *sack;
5920 /* Protect ourselves from reading too far into
5921 * the skb from a bogus sender.
5923 sack = (struct sctp_sackhdr *) chunk->skb->data;
5925 num_blocks = ntohs(sack->num_gap_ack_blocks);
5926 num_dup_tsns = ntohs(sack->num_dup_tsns);
5927 len = sizeof(struct sctp_sackhdr);
5928 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5929 if (len > chunk->skb->len)
5932 skb_pull(chunk->skb, len);
5937 /* Create an ABORT packet to be sent as a response, with the specified
5940 static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
5941 const struct sctp_endpoint *ep,
5942 const struct sctp_association *asoc,
5943 struct sctp_chunk *chunk,
5944 const void *payload,
5947 struct sctp_packet *packet;
5948 struct sctp_chunk *abort;
5950 packet = sctp_ootb_pkt_new(net, asoc, chunk);
5954 * The T bit will be set if the asoc is NULL.
5956 abort = sctp_make_abort(asoc, chunk, paylen);
5958 sctp_ootb_pkt_free(packet);
5962 /* Reflect vtag if T-Bit is set */
5963 if (sctp_test_T_bit(abort))
5964 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5966 /* Add specified error causes, i.e., payload, to the
5969 sctp_addto_chunk(abort, paylen, payload);
5971 /* Set the skb to the belonging sock for accounting. */
5972 abort->skb->sk = ep->base.sk;
5974 sctp_packet_append_chunk(packet, abort);
5981 /* Allocate a packet for responding in the OOTB conditions. */
5982 static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5983 const struct sctp_association *asoc,
5984 const struct sctp_chunk *chunk)
5986 struct sctp_packet *packet;
5987 struct sctp_transport *transport;
5992 /* Get the source and destination port from the inbound packet. */
5993 sport = ntohs(chunk->sctp_hdr->dest);
5994 dport = ntohs(chunk->sctp_hdr->source);
5996 /* The V-tag is going to be the same as the inbound packet if no
5997 * association exists, otherwise, use the peer's vtag.
6000 /* Special case the INIT-ACK as there is no peer's vtag
6003 switch (chunk->chunk_hdr->type) {
6004 case SCTP_CID_INIT_ACK:
6006 sctp_initack_chunk_t *initack;
6008 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6009 vtag = ntohl(initack->init_hdr.init_tag);
6013 vtag = asoc->peer.i.init_tag;
6017 /* Special case the INIT and stale COOKIE_ECHO as there is no
6020 switch (chunk->chunk_hdr->type) {
6023 sctp_init_chunk_t *init;
6025 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6026 vtag = ntohl(init->init_hdr.init_tag);
6030 vtag = ntohl(chunk->sctp_hdr->vtag);
6035 /* Make a transport for the bucket, Eliza... */
6036 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6040 /* Cache a route for the transport with the chunk's destination as
6041 * the source address.
6043 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6044 sctp_sk(net->sctp.ctl_sock));
6046 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
6047 packet = sctp_packet_config(packet, vtag, 0);
6055 /* Free the packet allocated earlier for responding in the OOTB condition. */
6056 void sctp_ootb_pkt_free(struct sctp_packet *packet)
6058 sctp_transport_free(packet->transport);
6061 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6062 static void sctp_send_stale_cookie_err(struct net *net,
6063 const struct sctp_endpoint *ep,
6064 const struct sctp_association *asoc,
6065 const struct sctp_chunk *chunk,
6066 sctp_cmd_seq_t *commands,
6067 struct sctp_chunk *err_chunk)
6069 struct sctp_packet *packet;
6072 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6074 struct sctp_signed_cookie *cookie;
6076 /* Override the OOTB vtag from the cookie. */
6077 cookie = chunk->subh.cookie_hdr;
6078 packet->vtag = cookie->c.peer_vtag;
6080 /* Set the skb to the belonging sock for accounting. */
6081 err_chunk->skb->sk = ep->base.sk;
6082 sctp_packet_append_chunk(packet, err_chunk);
6083 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6084 SCTP_PACKET(packet));
6085 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6087 sctp_chunk_free (err_chunk);
6092 /* Process a data chunk */
6093 static int sctp_eat_data(const struct sctp_association *asoc,
6094 struct sctp_chunk *chunk,
6095 sctp_cmd_seq_t *commands)
6097 sctp_datahdr_t *data_hdr;
6098 struct sctp_chunk *err;
6100 sctp_verb_t deliver;
6103 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6104 struct sock *sk = asoc->base.sk;
6105 struct net *net = sock_net(sk);
6110 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6111 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6113 tsn = ntohl(data_hdr->tsn);
6114 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6116 /* ASSERT: Now skb->data is really the user data. */
6118 /* Process ECN based congestion.
6120 * Since the chunk structure is reused for all chunks within
6121 * a packet, we use ecn_ce_done to track if we've already
6122 * done CE processing for this packet.
6124 * We need to do ECN processing even if we plan to discard the
6128 if (!chunk->ecn_ce_done) {
6130 chunk->ecn_ce_done = 1;
6132 af = sctp_get_af_specific(
6133 ipver2af(ip_hdr(chunk->skb)->version));
6135 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6136 /* Do real work as sideffect. */
6137 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6142 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6144 /* The TSN is too high--silently discard the chunk and
6145 * count on it getting retransmitted later.
6148 chunk->asoc->stats.outofseqtsns++;
6149 return SCTP_IERROR_HIGH_TSN;
6150 } else if (tmp > 0) {
6151 /* This is a duplicate. Record it. */
6152 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6153 return SCTP_IERROR_DUP_TSN;
6156 /* This is a new TSN. */
6158 /* Discard if there is no room in the receive window.
6159 * Actually, allow a little bit of overflow (up to a MTU).
6161 datalen = ntohs(chunk->chunk_hdr->length);
6162 datalen -= sizeof(sctp_data_chunk_t);
6164 deliver = SCTP_CMD_CHUNK_ULP;
6166 /* Think about partial delivery. */
6167 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6169 /* Even if we don't accept this chunk there is
6172 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6175 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6176 * seems a bit troublesome in that frag_point varies based on
6177 * PMTU. In cases, such as loopback, this might be a rather
6180 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6181 (datalen > asoc->rwnd + asoc->frag_point))) {
6183 /* If this is the next TSN, consider reneging to make
6184 * room. Note: Playing nice with a confused sender. A
6185 * malicious sender can still eat up all our buffer
6186 * space and in the future we may want to detect and
6187 * do more drastic reneging.
6189 if (sctp_tsnmap_has_gap(map) &&
6190 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6191 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6192 deliver = SCTP_CMD_RENEGE;
6194 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6195 __func__, tsn, datalen, asoc->rwnd);
6197 return SCTP_IERROR_IGNORE_TSN;
6202 * Also try to renege to limit our memory usage in the event that
6203 * we are under memory pressure
6204 * If we can't renege, don't worry about it, the sk_rmem_schedule
6205 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6206 * memory usage too much
6208 if (*sk->sk_prot_creator->memory_pressure) {
6209 if (sctp_tsnmap_has_gap(map) &&
6210 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6211 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6213 deliver = SCTP_CMD_RENEGE;
6218 * Section 3.3.10.9 No User Data (9)
6222 * No User Data: This error cause is returned to the originator of a
6223 * DATA chunk if a received DATA chunk has no user data.
6225 if (unlikely(0 == datalen)) {
6226 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6228 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6231 /* We are going to ABORT, so we might as well stop
6232 * processing the rest of the chunks in the packet.
6234 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6235 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6236 SCTP_ERROR(ECONNABORTED));
6237 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6238 SCTP_PERR(SCTP_ERROR_NO_DATA));
6239 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6240 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6241 return SCTP_IERROR_NO_DATA;
6244 chunk->data_accepted = 1;
6246 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6247 * if we renege and the chunk arrives again.
6249 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6250 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6252 chunk->asoc->stats.iuodchunks++;
6254 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6256 chunk->asoc->stats.iodchunks++;
6260 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6262 * If an endpoint receive a DATA chunk with an invalid stream
6263 * identifier, it shall acknowledge the reception of the DATA chunk
6264 * following the normal procedure, immediately send an ERROR chunk
6265 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6266 * and discard the DATA chunk.
6268 sid = ntohs(data_hdr->stream);
6269 if (sid >= asoc->c.sinit_max_instreams) {
6270 /* Mark tsn as received even though we drop it */
6271 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6273 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6275 sizeof(data_hdr->stream),
6278 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6280 return SCTP_IERROR_BAD_STREAM;
6283 /* Check to see if the SSN is possible for this TSN.
6284 * The biggest gap we can record is 4K wide. Since SSNs wrap
6285 * at an unsigned short, there is no way that an SSN can
6286 * wrap and for a valid TSN. We can simply check if the current
6287 * SSN is smaller then the next expected one. If it is, it wrapped
6290 ssn = ntohs(data_hdr->ssn);
6291 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6292 return SCTP_IERROR_PROTO_VIOLATION;
6295 /* Send the data up to the user. Note: Schedule the
6296 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6297 * chunk needs the updated rwnd.
6299 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6301 return SCTP_IERROR_NO_ERROR;