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 #define CREATE_TRACE_POINTS
63 #include <trace/events/sctp.h>
65 static struct sctp_packet *sctp_abort_pkt_new(
67 const struct sctp_endpoint *ep,
68 const struct sctp_association *asoc,
69 struct sctp_chunk *chunk,
70 const void *payload, size_t paylen);
71 static int sctp_eat_data(const struct sctp_association *asoc,
72 struct sctp_chunk *chunk,
73 struct sctp_cmd_seq *commands);
74 static struct sctp_packet *sctp_ootb_pkt_new(
76 const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78 static void sctp_send_stale_cookie_err(struct net *net,
79 const struct sctp_endpoint *ep,
80 const struct sctp_association *asoc,
81 const struct sctp_chunk *chunk,
82 struct sctp_cmd_seq *commands,
83 struct sctp_chunk *err_chunk);
84 static enum sctp_disposition sctp_sf_do_5_2_6_stale(
86 const struct sctp_endpoint *ep,
87 const struct sctp_association *asoc,
88 const union sctp_subtype type,
90 struct sctp_cmd_seq *commands);
91 static enum sctp_disposition sctp_sf_shut_8_4_5(
93 const struct sctp_endpoint *ep,
94 const struct sctp_association *asoc,
95 const union sctp_subtype type,
97 struct sctp_cmd_seq *commands);
98 static enum sctp_disposition sctp_sf_tabort_8_4_8(
100 const struct sctp_endpoint *ep,
101 const struct sctp_association *asoc,
102 const union sctp_subtype type,
104 struct sctp_cmd_seq *commands);
105 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
107 static enum sctp_disposition sctp_stop_t1_and_abort(
109 struct sctp_cmd_seq *commands,
110 __be16 error, int sk_err,
111 const struct sctp_association *asoc,
112 struct sctp_transport *transport);
114 static enum sctp_disposition sctp_sf_abort_violation(
116 const struct sctp_endpoint *ep,
117 const struct sctp_association *asoc,
119 struct sctp_cmd_seq *commands,
121 const size_t paylen);
123 static enum sctp_disposition sctp_sf_violation_chunklen(
125 const struct sctp_endpoint *ep,
126 const struct sctp_association *asoc,
127 const union sctp_subtype type,
129 struct sctp_cmd_seq *commands);
131 static enum sctp_disposition sctp_sf_violation_paramlen(
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const union sctp_subtype type,
136 void *arg, void *ext,
137 struct sctp_cmd_seq *commands);
139 static enum sctp_disposition sctp_sf_violation_ctsn(
141 const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const union sctp_subtype type,
145 struct sctp_cmd_seq *commands);
147 static enum sctp_disposition sctp_sf_violation_chunk(
149 const struct sctp_endpoint *ep,
150 const struct sctp_association *asoc,
151 const union sctp_subtype type,
153 struct sctp_cmd_seq *commands);
155 static enum sctp_ierror sctp_sf_authenticate(
157 const struct sctp_endpoint *ep,
158 const struct sctp_association *asoc,
159 const union sctp_subtype type,
160 struct sctp_chunk *chunk);
162 static enum sctp_disposition __sctp_sf_do_9_1_abort(
164 const struct sctp_endpoint *ep,
165 const struct sctp_association *asoc,
166 const union sctp_subtype type,
168 struct sctp_cmd_seq *commands);
170 /* Small helper function that checks if the chunk length
171 * is of the appropriate length. The 'required_length' argument
172 * is set to be the size of a specific chunk we are testing.
173 * Return Values: true = Valid length
174 * false = Invalid length
177 static inline bool sctp_chunk_length_valid(struct sctp_chunk *chunk,
178 __u16 required_length)
180 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
182 /* Previously already marked? */
183 if (unlikely(chunk->pdiscard))
185 if (unlikely(chunk_length < required_length))
191 /**********************************************************
192 * These are the state functions for handling chunk events.
193 **********************************************************/
196 * Process the final SHUTDOWN COMPLETE.
198 * Section: 4 (C) (diagram), 9.2
199 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
200 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
201 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
202 * should stop the T2-shutdown timer and remove all knowledge of the
203 * association (and thus the association enters the CLOSED state).
205 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
206 * C) Rules for packet carrying SHUTDOWN COMPLETE:
208 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
209 * if the Verification Tag field of the packet matches its own tag and
210 * the T bit is not set
212 * it is set to its peer's tag and the T bit is set in the Chunk
214 * Otherwise, the receiver MUST silently discard the packet
215 * and take no further action. An endpoint MUST ignore the
216 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
219 * (endpoint, asoc, chunk)
222 * (asoc, reply_msg, msg_up, timers, counters)
224 * The return value is the disposition of the chunk.
226 enum sctp_disposition sctp_sf_do_4_C(struct net *net,
227 const struct sctp_endpoint *ep,
228 const struct sctp_association *asoc,
229 const union sctp_subtype type,
230 void *arg, struct sctp_cmd_seq *commands)
232 struct sctp_chunk *chunk = arg;
233 struct sctp_ulpevent *ev;
235 if (!sctp_vtag_verify_either(chunk, asoc))
236 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
238 /* RFC 2960 6.10 Bundling
240 * An endpoint MUST NOT bundle INIT, INIT ACK or
241 * SHUTDOWN COMPLETE with any other chunks.
243 if (!chunk->singleton)
244 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
246 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
247 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
248 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
251 /* RFC 2960 10.2 SCTP-to-ULP
253 * H) SHUTDOWN COMPLETE notification
255 * When SCTP completes the shutdown procedures (section 9.2) this
256 * notification is passed to the upper layer.
258 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
259 0, 0, 0, NULL, GFP_ATOMIC);
261 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
264 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
265 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
266 * not the chunk should be discarded. If the endpoint is in
267 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
268 * T2-shutdown timer and remove all knowledge of the
269 * association (and thus the association enters the CLOSED
272 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
273 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
275 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
276 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
278 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
279 SCTP_STATE(SCTP_STATE_CLOSED));
281 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
282 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
284 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
286 return SCTP_DISPOSITION_DELETE_TCB;
290 * Respond to a normal INIT chunk.
291 * We are the side that is being asked for an association.
293 * Section: 5.1 Normal Establishment of an Association, B
294 * B) "Z" shall respond immediately with an INIT ACK chunk. The
295 * destination IP address of the INIT ACK MUST be set to the source
296 * IP address of the INIT to which this INIT ACK is responding. In
297 * the response, besides filling in other parameters, "Z" must set the
298 * Verification Tag field to Tag_A, and also provide its own
299 * Verification Tag (Tag_Z) in the Initiate Tag field.
301 * Verification Tag: Must be 0.
304 * (endpoint, asoc, chunk)
307 * (asoc, reply_msg, msg_up, timers, counters)
309 * The return value is the disposition of the chunk.
311 enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
312 const struct sctp_endpoint *ep,
313 const struct sctp_association *asoc,
314 const union sctp_subtype type,
316 struct sctp_cmd_seq *commands)
318 struct sctp_chunk *chunk = arg, *repl, *err_chunk;
319 struct sctp_unrecognized_param *unk_param;
320 struct sctp_association *new_asoc;
321 struct sctp_packet *packet;
324 /* Update socket peer label if first association. */
325 if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
327 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
330 * An endpoint MUST NOT bundle INIT, INIT ACK or
331 * SHUTDOWN COMPLETE with any other chunks.
334 * Furthermore, we require that the receiver of an INIT chunk MUST
335 * enforce these rules by silently discarding an arriving packet
336 * with an INIT chunk that is bundled with other chunks.
338 if (!chunk->singleton)
339 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
341 /* If the packet is an OOTB packet which is temporarily on the
342 * control endpoint, respond with an ABORT.
344 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
345 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
346 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
349 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
352 if (chunk->sctp_hdr->vtag != 0)
353 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
355 /* Make sure that the INIT chunk has a valid length.
356 * Normally, this would cause an ABORT with a Protocol Violation
357 * error, but since we don't have an association, we'll
358 * just discard the packet.
360 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
361 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
363 /* If the INIT is coming toward a closing socket, we'll send back
364 * and ABORT. Essentially, this catches the race of INIT being
365 * backloged to the socket at the same time as the user isses close().
366 * Since the socket and all its associations are going away, we
367 * can treat this OOTB
369 if (sctp_sstate(ep->base.sk, CLOSING))
370 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
372 /* Verify the INIT chunk before processing it. */
374 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
375 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
377 /* This chunk contains fatal error. It is to be discarded.
378 * Send an ABORT, with causes if there is any.
381 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
382 (__u8 *)(err_chunk->chunk_hdr) +
383 sizeof(struct sctp_chunkhdr),
384 ntohs(err_chunk->chunk_hdr->length) -
385 sizeof(struct sctp_chunkhdr));
387 sctp_chunk_free(err_chunk);
390 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
391 SCTP_PACKET(packet));
392 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
393 return SCTP_DISPOSITION_CONSUME;
395 return SCTP_DISPOSITION_NOMEM;
398 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
403 /* Grab the INIT header. */
404 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
406 /* Tag the variable length parameters. */
407 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
409 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
413 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
414 sctp_scope(sctp_source(chunk)),
418 /* The call, sctp_process_init(), can fail on memory allocation. */
419 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
420 (struct sctp_init_chunk *)chunk->chunk_hdr,
424 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
426 /* If there are errors need to be reported for unknown parameters,
427 * make sure to reserve enough room in the INIT ACK for them.
431 len = ntohs(err_chunk->chunk_hdr->length) -
432 sizeof(struct sctp_chunkhdr);
434 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
438 /* If there are errors need to be reported for unknown parameters,
439 * include them in the outgoing INIT ACK as "Unrecognized parameter"
443 /* Get the "Unrecognized parameter" parameter(s) out of the
444 * ERROR chunk generated by sctp_verify_init(). Since the
445 * error cause code for "unknown parameter" and the
446 * "Unrecognized parameter" type is the same, we can
447 * construct the parameters in INIT ACK by copying the
450 unk_param = (struct sctp_unrecognized_param *)
451 ((__u8 *)(err_chunk->chunk_hdr) +
452 sizeof(struct sctp_chunkhdr));
453 /* Replace the cause code with the "Unrecognized parameter"
456 sctp_addto_chunk(repl, len, unk_param);
457 sctp_chunk_free(err_chunk);
460 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
462 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
465 * Note: After sending out INIT ACK with the State Cookie parameter,
466 * "Z" MUST NOT allocate any resources, nor keep any states for the
467 * new association. Otherwise, "Z" will be vulnerable to resource
470 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
472 return SCTP_DISPOSITION_DELETE_TCB;
475 sctp_association_free(new_asoc);
478 sctp_chunk_free(err_chunk);
479 return SCTP_DISPOSITION_NOMEM;
483 * Respond to a normal INIT ACK chunk.
484 * We are the side that is initiating the association.
486 * Section: 5.1 Normal Establishment of an Association, C
487 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
488 * timer and leave COOKIE-WAIT state. "A" shall then send the State
489 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
490 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
492 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
493 * DATA chunks, but it MUST be the first chunk in the packet and
494 * until the COOKIE ACK is returned the sender MUST NOT send any
495 * other packets to the peer.
497 * Verification Tag: 3.3.3
498 * If the value of the Initiate Tag in a received INIT ACK chunk is
499 * found to be 0, the receiver MUST treat it as an error and close the
500 * association by transmitting an ABORT.
503 * (endpoint, asoc, chunk)
506 * (asoc, reply_msg, msg_up, timers, counters)
508 * The return value is the disposition of the chunk.
510 enum sctp_disposition sctp_sf_do_5_1C_ack(struct net *net,
511 const struct sctp_endpoint *ep,
512 const struct sctp_association *asoc,
513 const union sctp_subtype type,
515 struct sctp_cmd_seq *commands)
517 struct sctp_init_chunk *initchunk;
518 struct sctp_chunk *chunk = arg;
519 struct sctp_chunk *err_chunk;
520 struct sctp_packet *packet;
522 if (!sctp_vtag_verify(chunk, asoc))
523 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
526 * An endpoint MUST NOT bundle INIT, INIT ACK or
527 * SHUTDOWN COMPLETE with any other chunks.
529 if (!chunk->singleton)
530 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
532 /* Make sure that the INIT-ACK chunk has a valid length */
533 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_initack_chunk)))
534 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
536 /* Grab the INIT header. */
537 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
539 /* Verify the INIT chunk before processing it. */
541 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
542 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
545 enum sctp_error error = SCTP_ERROR_NO_RESOURCE;
547 /* This chunk contains fatal error. It is to be discarded.
548 * Send an ABORT, with causes. If there are no causes,
549 * then there wasn't enough memory. Just terminate
553 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
554 (__u8 *)(err_chunk->chunk_hdr) +
555 sizeof(struct sctp_chunkhdr),
556 ntohs(err_chunk->chunk_hdr->length) -
557 sizeof(struct sctp_chunkhdr));
559 sctp_chunk_free(err_chunk);
562 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
563 SCTP_PACKET(packet));
564 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
565 error = SCTP_ERROR_INV_PARAM;
569 /* SCTP-AUTH, Section 6.3:
570 * It should be noted that if the receiver wants to tear
571 * down an association in an authenticated way only, the
572 * handling of malformed packets should not result in
573 * tearing down the association.
575 * This means that if we only want to abort associations
576 * in an authenticated way (i.e AUTH+ABORT), then we
577 * can't destroy this association just because the packet
580 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
581 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
583 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
584 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
585 asoc, chunk->transport);
588 /* Tag the variable length parameters. Note that we never
589 * convert the parameters in an INIT chunk.
591 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
593 initchunk = (struct sctp_init_chunk *)chunk->chunk_hdr;
595 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
596 SCTP_PEER_INIT(initchunk));
598 /* Reset init error count upon receipt of INIT-ACK. */
599 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
601 /* 5.1 C) "A" shall stop the T1-init timer and leave
602 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
603 * timer, and enter the COOKIE-ECHOED state.
605 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
606 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
607 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
608 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
609 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
610 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
612 /* SCTP-AUTH: genereate the assocition shared keys so that
613 * we can potentially signe the COOKIE-ECHO.
615 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
617 /* 5.1 C) "A" shall then send the State Cookie received in the
618 * INIT ACK chunk in a COOKIE ECHO chunk, ...
620 /* If there is any errors to report, send the ERROR chunk generated
621 * for unknown parameters as well.
623 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
624 SCTP_CHUNK(err_chunk));
626 return SCTP_DISPOSITION_CONSUME;
630 * Respond to a normal COOKIE ECHO chunk.
631 * We are the side that is being asked for an association.
633 * Section: 5.1 Normal Establishment of an Association, D
634 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
635 * with a COOKIE ACK chunk after building a TCB and moving to
636 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
637 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
638 * chunk MUST be the first chunk in the packet.
640 * IMPLEMENTATION NOTE: An implementation may choose to send the
641 * Communication Up notification to the SCTP user upon reception
642 * of a valid COOKIE ECHO chunk.
644 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
645 * D) Rules for packet carrying a COOKIE ECHO
647 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
648 * Initial Tag received in the INIT ACK.
650 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
653 * (endpoint, asoc, chunk)
656 * (asoc, reply_msg, msg_up, timers, counters)
658 * The return value is the disposition of the chunk.
660 enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
661 const struct sctp_endpoint *ep,
662 const struct sctp_association *asoc,
663 const union sctp_subtype type,
665 struct sctp_cmd_seq *commands)
667 struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL;
668 struct sctp_association *new_asoc;
669 struct sctp_init_chunk *peer_init;
670 struct sctp_chunk *chunk = arg;
671 struct sctp_chunk *err_chk_p;
672 struct sctp_chunk *repl;
676 /* If the packet is an OOTB packet which is temporarily on the
677 * control endpoint, respond with an ABORT.
679 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
680 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
681 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
684 /* Make sure that the COOKIE_ECHO chunk has a valid length.
685 * In this case, we check that we have enough for at least a
686 * chunk header. More detailed verification is done
687 * in sctp_unpack_cookie().
689 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
690 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
692 /* If the endpoint is not listening or if the number of associations
693 * on the TCP-style socket exceed the max backlog, respond with an
697 if (!sctp_sstate(sk, LISTENING) ||
698 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
699 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
701 /* "Decode" the chunk. We have no optional parameters so we
704 chunk->subh.cookie_hdr =
705 (struct sctp_signed_cookie *)chunk->skb->data;
706 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
707 sizeof(struct sctp_chunkhdr)))
710 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
711 * "Z" will reply with a COOKIE ACK chunk after building a TCB
712 * and moving to the ESTABLISHED state.
714 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
718 * If the re-build failed, what is the proper error path
721 * [We should abort the association. --piggy]
724 /* FIXME: Several errors are possible. A bad cookie should
725 * be silently discarded, but think about logging it too.
728 case -SCTP_IERROR_NOMEM:
731 case -SCTP_IERROR_STALE_COOKIE:
732 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
734 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
736 case -SCTP_IERROR_BAD_SIG:
738 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
743 /* Delay state machine commands until later.
745 * Re-build the bind address for the association is done in
746 * the sctp_unpack_cookie() already.
748 /* This is a brand-new association, so these are not yet side
749 * effects--it is safe to run them here.
751 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
753 if (!sctp_process_init(new_asoc, chunk,
754 &chunk->subh.cookie_hdr->c.peer_addr,
755 peer_init, GFP_ATOMIC))
758 /* SCTP-AUTH: Now that we've populate required fields in
759 * sctp_process_init, set up the assocaition shared keys as
760 * necessary so that we can potentially authenticate the ACK
762 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
766 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
767 * is supposed to be authenticated and we have to do delayed
768 * authentication. We've just recreated the association using
769 * the information in the cookie and now it's much easier to
770 * do the authentication.
772 if (chunk->auth_chunk) {
773 struct sctp_chunk auth;
774 enum sctp_ierror ret;
776 /* Make sure that we and the peer are AUTH capable */
777 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
778 sctp_association_free(new_asoc);
779 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
782 /* set-up our fake chunk so that we can process it */
783 auth.skb = chunk->auth_chunk;
784 auth.asoc = chunk->asoc;
785 auth.sctp_hdr = chunk->sctp_hdr;
786 auth.chunk_hdr = (struct sctp_chunkhdr *)
787 skb_push(chunk->auth_chunk,
788 sizeof(struct sctp_chunkhdr));
789 skb_pull(chunk->auth_chunk, sizeof(struct sctp_chunkhdr));
790 auth.transport = chunk->transport;
792 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
793 if (ret != SCTP_IERROR_NO_ERROR) {
794 sctp_association_free(new_asoc);
795 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
799 repl = sctp_make_cookie_ack(new_asoc, chunk);
803 /* RFC 2960 5.1 Normal Establishment of an Association
805 * D) IMPLEMENTATION NOTE: An implementation may choose to
806 * send the Communication Up notification to the SCTP user
807 * upon reception of a valid COOKIE ECHO chunk.
809 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
810 new_asoc->c.sinit_num_ostreams,
811 new_asoc->c.sinit_max_instreams,
816 /* Sockets API Draft Section 5.3.1.6
817 * When a peer sends a Adaptation Layer Indication parameter , SCTP
818 * delivers this notification to inform the application that of the
819 * peers requested adaptation layer.
821 if (new_asoc->peer.adaptation_ind) {
822 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
828 if (!new_asoc->peer.auth_capable) {
829 auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0,
836 /* Add all the state machine commands now since we've created
837 * everything. This way we don't introduce memory corruptions
838 * during side-effect processing and correclty count established
841 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
842 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
843 SCTP_STATE(SCTP_STATE_ESTABLISHED));
844 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
845 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
846 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
848 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
849 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
850 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
852 /* This will send the COOKIE ACK */
853 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
855 /* Queue the ASSOC_CHANGE event */
856 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
858 /* Send up the Adaptation Layer Indication event */
860 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
861 SCTP_ULPEVENT(ai_ev));
864 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
865 SCTP_ULPEVENT(auth_ev));
867 return SCTP_DISPOSITION_CONSUME;
870 sctp_ulpevent_free(ai_ev);
872 sctp_ulpevent_free(ev);
874 sctp_chunk_free(repl);
876 sctp_association_free(new_asoc);
878 return SCTP_DISPOSITION_NOMEM;
882 * Respond to a normal COOKIE ACK chunk.
883 * We are the side that is asking for an association.
885 * RFC 2960 5.1 Normal Establishment of an Association
887 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
888 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
889 * timer. It may also notify its ULP about the successful
890 * establishment of the association with a Communication Up
891 * notification (see Section 10).
895 * (endpoint, asoc, chunk)
898 * (asoc, reply_msg, msg_up, timers, counters)
900 * The return value is the disposition of the chunk.
902 enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net,
903 const struct sctp_endpoint *ep,
904 const struct sctp_association *asoc,
905 const union sctp_subtype type,
907 struct sctp_cmd_seq *commands)
909 struct sctp_chunk *chunk = arg;
910 struct sctp_ulpevent *ev;
912 if (!sctp_vtag_verify(chunk, asoc))
913 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
915 /* Verify that the chunk length for the COOKIE-ACK is OK.
916 * If we don't do this, any bundled chunks may be junked.
918 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
919 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
922 /* Reset init error count upon receipt of COOKIE-ACK,
923 * to avoid problems with the managemement of this
924 * counter in stale cookie situations when a transition back
925 * from the COOKIE-ECHOED state to the COOKIE-WAIT
926 * state is performed.
928 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
930 /* Set peer label for connection. */
931 security_inet_conn_established(ep->base.sk, chunk->skb);
933 /* RFC 2960 5.1 Normal Establishment of an Association
935 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
936 * from the COOKIE-ECHOED state to the ESTABLISHED state,
937 * stopping the T1-cookie timer.
939 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
940 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
941 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
942 SCTP_STATE(SCTP_STATE_ESTABLISHED));
943 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
944 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
945 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
946 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
947 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
948 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
950 /* It may also notify its ULP about the successful
951 * establishment of the association with a Communication Up
952 * notification (see Section 10).
954 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
955 0, asoc->c.sinit_num_ostreams,
956 asoc->c.sinit_max_instreams,
962 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
964 /* Sockets API Draft Section 5.3.1.6
965 * When a peer sends a Adaptation Layer Indication parameter , SCTP
966 * delivers this notification to inform the application that of the
967 * peers requested adaptation layer.
969 if (asoc->peer.adaptation_ind) {
970 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
974 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
978 if (!asoc->peer.auth_capable) {
979 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH,
983 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
987 return SCTP_DISPOSITION_CONSUME;
989 return SCTP_DISPOSITION_NOMEM;
992 /* Generate and sendout a heartbeat packet. */
993 static enum sctp_disposition sctp_sf_heartbeat(
994 const struct sctp_endpoint *ep,
995 const struct sctp_association *asoc,
996 const union sctp_subtype type,
998 struct sctp_cmd_seq *commands)
1000 struct sctp_transport *transport = (struct sctp_transport *) arg;
1001 struct sctp_chunk *reply;
1003 /* Send a heartbeat to our peer. */
1004 reply = sctp_make_heartbeat(asoc, transport);
1006 return SCTP_DISPOSITION_NOMEM;
1008 /* Set rto_pending indicating that an RTT measurement
1009 * is started with this heartbeat chunk.
1011 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
1012 SCTP_TRANSPORT(transport));
1014 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1015 return SCTP_DISPOSITION_CONSUME;
1018 /* Generate a HEARTBEAT packet on the given transport. */
1019 enum sctp_disposition sctp_sf_sendbeat_8_3(struct net *net,
1020 const struct sctp_endpoint *ep,
1021 const struct sctp_association *asoc,
1022 const union sctp_subtype type,
1024 struct sctp_cmd_seq *commands)
1026 struct sctp_transport *transport = (struct sctp_transport *) arg;
1028 if (asoc->overall_error_count >= asoc->max_retrans) {
1029 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1030 SCTP_ERROR(ETIMEDOUT));
1031 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1032 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1033 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1034 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1035 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1036 return SCTP_DISPOSITION_DELETE_TCB;
1040 * The Sender-specific Heartbeat Info field should normally include
1041 * information about the sender's current time when this HEARTBEAT
1042 * chunk is sent and the destination transport address to which this
1043 * HEARTBEAT is sent (see Section 8.3).
1046 if (transport->param_flags & SPP_HB_ENABLE) {
1047 if (SCTP_DISPOSITION_NOMEM ==
1048 sctp_sf_heartbeat(ep, asoc, type, arg,
1050 return SCTP_DISPOSITION_NOMEM;
1052 /* Set transport error counter and association error counter
1053 * when sending heartbeat.
1055 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1056 SCTP_TRANSPORT(transport));
1058 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1059 SCTP_TRANSPORT(transport));
1060 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1061 SCTP_TRANSPORT(transport));
1063 return SCTP_DISPOSITION_CONSUME;
1066 /* resend asoc strreset_chunk. */
1067 enum sctp_disposition sctp_sf_send_reconf(struct net *net,
1068 const struct sctp_endpoint *ep,
1069 const struct sctp_association *asoc,
1070 const union sctp_subtype type,
1072 struct sctp_cmd_seq *commands)
1074 struct sctp_transport *transport = arg;
1076 if (asoc->overall_error_count >= asoc->max_retrans) {
1077 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1078 SCTP_ERROR(ETIMEDOUT));
1079 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1080 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1081 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1082 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1083 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1084 return SCTP_DISPOSITION_DELETE_TCB;
1087 sctp_chunk_hold(asoc->strreset_chunk);
1088 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1089 SCTP_CHUNK(asoc->strreset_chunk));
1090 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
1092 return SCTP_DISPOSITION_CONSUME;
1096 * Process an heartbeat request.
1098 * Section: 8.3 Path Heartbeat
1099 * The receiver of the HEARTBEAT should immediately respond with a
1100 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1101 * from the received HEARTBEAT chunk.
1103 * Verification Tag: 8.5 Verification Tag [Normal verification]
1104 * When receiving an SCTP packet, the endpoint MUST ensure that the
1105 * value in the Verification Tag field of the received SCTP packet
1106 * matches its own Tag. If the received Verification Tag value does not
1107 * match the receiver's own tag value, the receiver shall silently
1108 * discard the packet and shall not process it any further except for
1109 * those cases listed in Section 8.5.1 below.
1112 * (endpoint, asoc, chunk)
1115 * (asoc, reply_msg, msg_up, timers, counters)
1117 * The return value is the disposition of the chunk.
1119 enum sctp_disposition sctp_sf_beat_8_3(struct net *net,
1120 const struct sctp_endpoint *ep,
1121 const struct sctp_association *asoc,
1122 const union sctp_subtype type,
1123 void *arg, struct sctp_cmd_seq *commands)
1125 struct sctp_paramhdr *param_hdr;
1126 struct sctp_chunk *chunk = arg;
1127 struct sctp_chunk *reply;
1130 if (!sctp_vtag_verify(chunk, asoc))
1131 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1133 /* Make sure that the HEARTBEAT chunk has a valid length. */
1134 if (!sctp_chunk_length_valid(chunk,
1135 sizeof(struct sctp_heartbeat_chunk)))
1136 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1139 /* 8.3 The receiver of the HEARTBEAT should immediately
1140 * respond with a HEARTBEAT ACK that contains the Heartbeat
1141 * Information field copied from the received HEARTBEAT chunk.
1143 chunk->subh.hb_hdr = (struct sctp_heartbeathdr *)chunk->skb->data;
1144 param_hdr = (struct sctp_paramhdr *)chunk->subh.hb_hdr;
1145 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(struct sctp_chunkhdr);
1147 if (ntohs(param_hdr->length) > paylen)
1148 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1149 param_hdr, commands);
1151 if (!pskb_pull(chunk->skb, paylen))
1154 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1158 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1159 return SCTP_DISPOSITION_CONSUME;
1162 return SCTP_DISPOSITION_NOMEM;
1166 * Process the returning HEARTBEAT ACK.
1168 * Section: 8.3 Path Heartbeat
1169 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1170 * should clear the error counter of the destination transport
1171 * address to which the HEARTBEAT was sent, and mark the destination
1172 * transport address as active if it is not so marked. The endpoint may
1173 * optionally report to the upper layer when an inactive destination
1174 * address is marked as active due to the reception of the latest
1175 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1176 * clear the association overall error count as well (as defined
1179 * The receiver of the HEARTBEAT ACK should also perform an RTT
1180 * measurement for that destination transport address using the time
1181 * value carried in the HEARTBEAT ACK chunk.
1183 * Verification Tag: 8.5 Verification Tag [Normal verification]
1186 * (endpoint, asoc, chunk)
1189 * (asoc, reply_msg, msg_up, timers, counters)
1191 * The return value is the disposition of the chunk.
1193 enum sctp_disposition sctp_sf_backbeat_8_3(struct net *net,
1194 const struct sctp_endpoint *ep,
1195 const struct sctp_association *asoc,
1196 const union sctp_subtype type,
1198 struct sctp_cmd_seq *commands)
1200 struct sctp_sender_hb_info *hbinfo;
1201 struct sctp_chunk *chunk = arg;
1202 struct sctp_transport *link;
1203 unsigned long max_interval;
1204 union sctp_addr from_addr;
1206 if (!sctp_vtag_verify(chunk, asoc))
1207 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1209 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1210 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr) +
1212 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1215 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
1216 /* Make sure that the length of the parameter is what we expect */
1217 if (ntohs(hbinfo->param_hdr.length) != sizeof(*hbinfo))
1218 return SCTP_DISPOSITION_DISCARD;
1220 from_addr = hbinfo->daddr;
1221 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1223 /* This should never happen, but lets log it if so. */
1224 if (unlikely(!link)) {
1225 if (from_addr.sa.sa_family == AF_INET6) {
1226 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1229 &from_addr.v6.sin6_addr);
1231 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1234 &from_addr.v4.sin_addr.s_addr);
1236 return SCTP_DISPOSITION_DISCARD;
1239 /* Validate the 64-bit random nonce. */
1240 if (hbinfo->hb_nonce != link->hb_nonce)
1241 return SCTP_DISPOSITION_DISCARD;
1243 max_interval = link->hbinterval + link->rto;
1245 /* Check if the timestamp looks valid. */
1246 if (time_after(hbinfo->sent_at, jiffies) ||
1247 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1248 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1249 "for transport:%p\n", __func__, link);
1251 return SCTP_DISPOSITION_DISCARD;
1254 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1255 * the HEARTBEAT should clear the error counter of the
1256 * destination transport address to which the HEARTBEAT was
1257 * sent and mark the destination transport address as active if
1258 * it is not so marked.
1260 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1262 return SCTP_DISPOSITION_CONSUME;
1265 /* Helper function to send out an abort for the restart
1268 static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1269 struct sctp_chunk *init,
1270 struct sctp_cmd_seq *commands)
1272 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1273 union sctp_addr_param *addrparm;
1274 struct sctp_errhdr *errhdr;
1275 char buffer[sizeof(*errhdr) + sizeof(*addrparm)];
1276 struct sctp_endpoint *ep;
1277 struct sctp_packet *pkt;
1280 /* Build the error on the stack. We are way to malloc crazy
1281 * throughout the code today.
1283 errhdr = (struct sctp_errhdr *)buffer;
1284 addrparm = (union sctp_addr_param *)errhdr->variable;
1286 /* Copy into a parm format. */
1287 len = af->to_addr_param(ssa, addrparm);
1288 len += sizeof(*errhdr);
1290 errhdr->cause = SCTP_ERROR_RESTART;
1291 errhdr->length = htons(len);
1293 /* Assign to the control socket. */
1294 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1296 /* Association is NULL since this may be a restart attack and we
1297 * want to send back the attacker's vtag.
1299 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1303 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1305 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1307 /* Discard the rest of the inbound packet. */
1308 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1311 /* Even if there is no memory, treat as a failure so
1312 * the packet will get dropped.
1317 static bool list_has_sctp_addr(const struct list_head *list,
1318 union sctp_addr *ipaddr)
1320 struct sctp_transport *addr;
1322 list_for_each_entry(addr, list, transports) {
1323 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1329 /* A restart is occurring, check to make sure no new addresses
1330 * are being added as we may be under a takeover attack.
1332 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1333 const struct sctp_association *asoc,
1334 struct sctp_chunk *init,
1335 struct sctp_cmd_seq *commands)
1337 struct net *net = sock_net(new_asoc->base.sk);
1338 struct sctp_transport *new_addr;
1341 /* Implementor's Guide - Section 5.2.2
1343 * Before responding the endpoint MUST check to see if the
1344 * unexpected INIT adds new addresses to the association. If new
1345 * addresses are added to the association, the endpoint MUST respond
1349 /* Search through all current addresses and make sure
1350 * we aren't adding any new ones.
1352 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1354 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1355 &new_addr->ipaddr)) {
1356 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
1363 /* Return success if all addresses were found. */
1367 /* Populate the verification/tie tags based on overlapping INIT
1370 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1372 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1373 const struct sctp_association *asoc)
1375 switch (asoc->state) {
1377 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1379 case SCTP_STATE_COOKIE_WAIT:
1380 new_asoc->c.my_vtag = asoc->c.my_vtag;
1381 new_asoc->c.my_ttag = asoc->c.my_vtag;
1382 new_asoc->c.peer_ttag = 0;
1385 case SCTP_STATE_COOKIE_ECHOED:
1386 new_asoc->c.my_vtag = asoc->c.my_vtag;
1387 new_asoc->c.my_ttag = asoc->c.my_vtag;
1388 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1391 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1392 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1395 new_asoc->c.my_ttag = asoc->c.my_vtag;
1396 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1400 /* Other parameters for the endpoint SHOULD be copied from the
1401 * existing parameters of the association (e.g. number of
1402 * outbound streams) into the INIT ACK and cookie.
1404 new_asoc->rwnd = asoc->rwnd;
1405 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1406 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1407 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1411 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1414 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1416 * Returns value representing action to be taken. These action values
1417 * correspond to Action/Description values in RFC 2960, Table 2.
1419 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1420 const struct sctp_association *asoc)
1422 /* In this case, the peer may have restarted. */
1423 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1424 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1425 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1426 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1429 /* Collision case B. */
1430 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1431 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1432 (0 == asoc->c.peer_vtag))) {
1436 /* Collision case D. */
1437 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1438 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1441 /* Collision case C. */
1442 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1443 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1444 (0 == new_asoc->c.my_ttag) &&
1445 (0 == new_asoc->c.peer_ttag))
1448 /* No match to any of the special cases; discard this packet. */
1452 /* Common helper routine for both duplicate and simulataneous INIT
1455 static enum sctp_disposition sctp_sf_do_unexpected_init(
1457 const struct sctp_endpoint *ep,
1458 const struct sctp_association *asoc,
1459 const union sctp_subtype type,
1461 struct sctp_cmd_seq *commands)
1463 struct sctp_chunk *chunk = arg, *repl, *err_chunk;
1464 struct sctp_unrecognized_param *unk_param;
1465 struct sctp_association *new_asoc;
1466 enum sctp_disposition retval;
1467 struct sctp_packet *packet;
1470 /* Update socket peer label if first association. */
1471 if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
1473 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1476 * An endpoint MUST NOT bundle INIT, INIT ACK or
1477 * SHUTDOWN COMPLETE with any other chunks.
1480 * Furthermore, we require that the receiver of an INIT chunk MUST
1481 * enforce these rules by silently discarding an arriving packet
1482 * with an INIT chunk that is bundled with other chunks.
1484 if (!chunk->singleton)
1485 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1487 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1490 if (chunk->sctp_hdr->vtag != 0)
1491 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1493 /* Make sure that the INIT chunk has a valid length.
1494 * In this case, we generate a protocol violation since we have
1495 * an association established.
1497 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
1498 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1500 /* Grab the INIT header. */
1501 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
1503 /* Tag the variable length parameters. */
1504 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
1506 /* Verify the INIT chunk before processing it. */
1508 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1509 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
1511 /* This chunk contains fatal error. It is to be discarded.
1512 * Send an ABORT, with causes if there is any.
1515 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1516 (__u8 *)(err_chunk->chunk_hdr) +
1517 sizeof(struct sctp_chunkhdr),
1518 ntohs(err_chunk->chunk_hdr->length) -
1519 sizeof(struct sctp_chunkhdr));
1522 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1523 SCTP_PACKET(packet));
1524 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1525 retval = SCTP_DISPOSITION_CONSUME;
1527 retval = SCTP_DISPOSITION_NOMEM;
1531 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1537 * Other parameters for the endpoint SHOULD be copied from the
1538 * existing parameters of the association (e.g. number of
1539 * outbound streams) into the INIT ACK and cookie.
1540 * FIXME: We are copying parameters from the endpoint not the
1543 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1547 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1548 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1551 /* In the outbound INIT ACK the endpoint MUST copy its current
1552 * Verification Tag and Peers Verification tag into a reserved
1553 * place (local tie-tag and per tie-tag) within the state cookie.
1555 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1556 (struct sctp_init_chunk *)chunk->chunk_hdr,
1560 /* Make sure no new addresses are being added during the
1561 * restart. Do not do this check for COOKIE-WAIT state,
1562 * since there are no peer addresses to check against.
1563 * Upon return an ABORT will have been sent if needed.
1565 if (!sctp_state(asoc, COOKIE_WAIT)) {
1566 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1568 retval = SCTP_DISPOSITION_CONSUME;
1573 sctp_tietags_populate(new_asoc, asoc);
1575 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1577 /* If there are errors need to be reported for unknown parameters,
1578 * make sure to reserve enough room in the INIT ACK for them.
1582 len = ntohs(err_chunk->chunk_hdr->length) -
1583 sizeof(struct sctp_chunkhdr);
1586 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1590 /* If there are errors need to be reported for unknown parameters,
1591 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1595 /* Get the "Unrecognized parameter" parameter(s) out of the
1596 * ERROR chunk generated by sctp_verify_init(). Since the
1597 * error cause code for "unknown parameter" and the
1598 * "Unrecognized parameter" type is the same, we can
1599 * construct the parameters in INIT ACK by copying the
1600 * ERROR causes over.
1602 unk_param = (struct sctp_unrecognized_param *)
1603 ((__u8 *)(err_chunk->chunk_hdr) +
1604 sizeof(struct sctp_chunkhdr));
1605 /* Replace the cause code with the "Unrecognized parameter"
1608 sctp_addto_chunk(repl, len, unk_param);
1611 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1612 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1615 * Note: After sending out INIT ACK with the State Cookie parameter,
1616 * "Z" MUST NOT allocate any resources for this new association.
1617 * Otherwise, "Z" will be vulnerable to resource attacks.
1619 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1620 retval = SCTP_DISPOSITION_CONSUME;
1625 retval = SCTP_DISPOSITION_NOMEM;
1628 sctp_association_free(new_asoc);
1631 sctp_chunk_free(err_chunk);
1636 * Handle simultaneous INIT.
1637 * This means we started an INIT and then we got an INIT request from
1640 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1641 * This usually indicates an initialization collision, i.e., each
1642 * endpoint is attempting, at about the same time, to establish an
1643 * association with the other endpoint.
1645 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1646 * endpoint MUST respond with an INIT ACK using the same parameters it
1647 * sent in its original INIT chunk (including its Verification Tag,
1648 * unchanged). These original parameters are combined with those from the
1649 * newly received INIT chunk. The endpoint shall also generate a State
1650 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1651 * INIT to calculate the State Cookie.
1653 * After that, the endpoint MUST NOT change its state, the T1-init
1654 * timer shall be left running and the corresponding TCB MUST NOT be
1655 * destroyed. The normal procedures for handling State Cookies when
1656 * a TCB exists will resolve the duplicate INITs to a single association.
1658 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1659 * its Tie-Tags with the Tag information of itself and its peer (see
1660 * section 5.2.2 for a description of the Tie-Tags).
1662 * Verification Tag: Not explicit, but an INIT can not have a valid
1663 * verification tag, so we skip the check.
1666 * (endpoint, asoc, chunk)
1669 * (asoc, reply_msg, msg_up, timers, counters)
1671 * The return value is the disposition of the chunk.
1673 enum sctp_disposition sctp_sf_do_5_2_1_siminit(
1675 const struct sctp_endpoint *ep,
1676 const struct sctp_association *asoc,
1677 const union sctp_subtype type,
1679 struct sctp_cmd_seq *commands)
1681 /* Call helper to do the real work for both simulataneous and
1682 * duplicate INIT chunk handling.
1684 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1688 * Handle duplicated INIT messages. These are usually delayed
1691 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1692 * COOKIE-ECHOED and COOKIE-WAIT
1694 * Unless otherwise stated, upon reception of an unexpected INIT for
1695 * this association, the endpoint shall generate an INIT ACK with a
1696 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1697 * current Verification Tag and peer's Verification Tag into a reserved
1698 * place within the state cookie. We shall refer to these locations as
1699 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1700 * containing this INIT ACK MUST carry a Verification Tag value equal to
1701 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1702 * MUST contain a new Initiation Tag (randomly generated see Section
1703 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1704 * existing parameters of the association (e.g. number of outbound
1705 * streams) into the INIT ACK and cookie.
1707 * After sending out the INIT ACK, the endpoint shall take no further
1708 * actions, i.e., the existing association, including its current state,
1709 * and the corresponding TCB MUST NOT be changed.
1711 * Note: Only when a TCB exists and the association is not in a COOKIE-
1712 * WAIT state are the Tie-Tags populated. For a normal association INIT
1713 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1714 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1715 * State Cookie are populated as specified in section 5.2.1.
1717 * Verification Tag: Not specified, but an INIT has no way of knowing
1718 * what the verification tag could be, so we ignore it.
1721 * (endpoint, asoc, chunk)
1724 * (asoc, reply_msg, msg_up, timers, counters)
1726 * The return value is the disposition of the chunk.
1728 enum sctp_disposition sctp_sf_do_5_2_2_dupinit(
1730 const struct sctp_endpoint *ep,
1731 const struct sctp_association *asoc,
1732 const union sctp_subtype type,
1734 struct sctp_cmd_seq *commands)
1736 /* Call helper to do the real work for both simulataneous and
1737 * duplicate INIT chunk handling.
1739 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1744 * Unexpected INIT-ACK handler.
1747 * If an INIT ACK received by an endpoint in any state other than the
1748 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1749 * An unexpected INIT ACK usually indicates the processing of an old or
1750 * duplicated INIT chunk.
1752 enum sctp_disposition sctp_sf_do_5_2_3_initack(
1754 const struct sctp_endpoint *ep,
1755 const struct sctp_association *asoc,
1756 const union sctp_subtype type,
1758 struct sctp_cmd_seq *commands)
1760 /* Per the above section, we'll discard the chunk if we have an
1761 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1763 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
1764 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
1766 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
1769 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1772 * A) In this case, the peer may have restarted.
1774 static enum sctp_disposition sctp_sf_do_dupcook_a(
1776 const struct sctp_endpoint *ep,
1777 const struct sctp_association *asoc,
1778 struct sctp_chunk *chunk,
1779 struct sctp_cmd_seq *commands,
1780 struct sctp_association *new_asoc)
1782 struct sctp_init_chunk *peer_init;
1783 enum sctp_disposition disposition;
1784 struct sctp_ulpevent *ev;
1785 struct sctp_chunk *repl;
1786 struct sctp_chunk *err;
1788 /* new_asoc is a brand-new association, so these are not yet
1789 * side effects--it is safe to run them here.
1791 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1793 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1797 /* Make sure no new addresses are being added during the
1798 * restart. Though this is a pretty complicated attack
1799 * since you'd have to get inside the cookie.
1801 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1802 return SCTP_DISPOSITION_CONSUME;
1805 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1806 * the peer has restarted (Action A), it MUST NOT setup a new
1807 * association but instead resend the SHUTDOWN ACK and send an ERROR
1808 * chunk with a "Cookie Received while Shutting Down" error cause to
1811 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1812 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1813 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1815 if (SCTP_DISPOSITION_NOMEM == disposition)
1818 err = sctp_make_op_error(asoc, chunk,
1819 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1822 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1825 return SCTP_DISPOSITION_CONSUME;
1828 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1829 * data. Consider the optional choice of resending of this data.
1831 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1832 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1833 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1834 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1836 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1837 * and ASCONF-ACK cache.
1839 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1840 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1841 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1843 repl = sctp_make_cookie_ack(new_asoc, chunk);
1847 /* Report association restart to upper layer. */
1848 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1849 new_asoc->c.sinit_num_ostreams,
1850 new_asoc->c.sinit_max_instreams,
1855 /* Update the content of current association. */
1856 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1857 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1858 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
1859 (sctp_sstate(asoc->base.sk, CLOSING) ||
1860 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1861 /* if were currently in SHUTDOWN_PENDING, but the socket
1862 * has been closed by user, don't transition to ESTABLISHED.
1863 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1865 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1866 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1867 SCTP_ST_CHUNK(0), NULL,
1870 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1871 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1872 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1874 return SCTP_DISPOSITION_CONSUME;
1877 sctp_chunk_free(repl);
1879 return SCTP_DISPOSITION_NOMEM;
1882 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1885 * B) In this case, both sides may be attempting to start an association
1886 * at about the same time but the peer endpoint started its INIT
1887 * after responding to the local endpoint's INIT
1889 /* This case represents an initialization collision. */
1890 static enum sctp_disposition sctp_sf_do_dupcook_b(
1892 const struct sctp_endpoint *ep,
1893 const struct sctp_association *asoc,
1894 struct sctp_chunk *chunk,
1895 struct sctp_cmd_seq *commands,
1896 struct sctp_association *new_asoc)
1898 struct sctp_init_chunk *peer_init;
1899 struct sctp_chunk *repl;
1901 /* new_asoc is a brand-new association, so these are not yet
1902 * side effects--it is safe to run them here.
1904 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1905 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1909 /* Update the content of current association. */
1910 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1911 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1912 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1913 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1914 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1916 repl = sctp_make_cookie_ack(new_asoc, chunk);
1920 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1922 /* RFC 2960 5.1 Normal Establishment of an Association
1924 * D) IMPLEMENTATION NOTE: An implementation may choose to
1925 * send the Communication Up notification to the SCTP user
1926 * upon reception of a valid COOKIE ECHO chunk.
1928 * Sadly, this needs to be implemented as a side-effect, because
1929 * we are not guaranteed to have set the association id of the real
1930 * association and so these notifications need to be delayed until
1931 * the association id is allocated.
1934 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1936 /* Sockets API Draft Section 5.3.1.6
1937 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1938 * delivers this notification to inform the application that of the
1939 * peers requested adaptation layer.
1941 * This also needs to be done as a side effect for the same reason as
1944 if (asoc->peer.adaptation_ind)
1945 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1947 if (!asoc->peer.auth_capable)
1948 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL());
1950 return SCTP_DISPOSITION_CONSUME;
1953 return SCTP_DISPOSITION_NOMEM;
1956 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1959 * C) In this case, the local endpoint's cookie has arrived late.
1960 * Before it arrived, the local endpoint sent an INIT and received an
1961 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1962 * but a new tag of its own.
1964 /* This case represents an initialization collision. */
1965 static enum sctp_disposition sctp_sf_do_dupcook_c(
1967 const struct sctp_endpoint *ep,
1968 const struct sctp_association *asoc,
1969 struct sctp_chunk *chunk,
1970 struct sctp_cmd_seq *commands,
1971 struct sctp_association *new_asoc)
1973 /* The cookie should be silently discarded.
1974 * The endpoint SHOULD NOT change states and should leave
1975 * any timers running.
1977 return SCTP_DISPOSITION_DISCARD;
1980 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1984 * D) When both local and remote tags match the endpoint should always
1985 * enter the ESTABLISHED state, if it has not already done so.
1987 /* This case represents an initialization collision. */
1988 static enum sctp_disposition sctp_sf_do_dupcook_d(
1990 const struct sctp_endpoint *ep,
1991 const struct sctp_association *asoc,
1992 struct sctp_chunk *chunk,
1993 struct sctp_cmd_seq *commands,
1994 struct sctp_association *new_asoc)
1996 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL;
1997 struct sctp_chunk *repl;
1999 /* Clarification from Implementor's Guide:
2000 * D) When both local and remote tags match the endpoint should
2001 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
2002 * It should stop any cookie timer that may be running and send
2006 /* Don't accidentally move back into established state. */
2007 if (asoc->state < SCTP_STATE_ESTABLISHED) {
2008 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2009 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2010 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2011 SCTP_STATE(SCTP_STATE_ESTABLISHED));
2012 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
2013 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
2016 /* RFC 2960 5.1 Normal Establishment of an Association
2018 * D) IMPLEMENTATION NOTE: An implementation may choose
2019 * to send the Communication Up notification to the
2020 * SCTP user upon reception of a valid COOKIE
2023 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
2025 asoc->c.sinit_num_ostreams,
2026 asoc->c.sinit_max_instreams,
2031 /* Sockets API Draft Section 5.3.1.6
2032 * When a peer sends a Adaptation Layer Indication parameter,
2033 * SCTP delivers this notification to inform the application
2034 * that of the peers requested adaptation layer.
2036 if (asoc->peer.adaptation_ind) {
2037 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
2044 if (!asoc->peer.auth_capable) {
2045 auth_ev = sctp_ulpevent_make_authkey(asoc, 0,
2053 repl = sctp_make_cookie_ack(new_asoc, chunk);
2057 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
2060 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2063 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2064 SCTP_ULPEVENT(ai_ev));
2066 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2067 SCTP_ULPEVENT(auth_ev));
2069 return SCTP_DISPOSITION_CONSUME;
2073 sctp_ulpevent_free(auth_ev);
2075 sctp_ulpevent_free(ai_ev);
2077 sctp_ulpevent_free(ev);
2078 return SCTP_DISPOSITION_NOMEM;
2082 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2083 * chunk was retransmitted and then delayed in the network.
2085 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2087 * Verification Tag: None. Do cookie validation.
2090 * (endpoint, asoc, chunk)
2093 * (asoc, reply_msg, msg_up, timers, counters)
2095 * The return value is the disposition of the chunk.
2097 enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
2099 const struct sctp_endpoint *ep,
2100 const struct sctp_association *asoc,
2101 const union sctp_subtype type,
2103 struct sctp_cmd_seq *commands)
2105 struct sctp_association *new_asoc;
2106 struct sctp_chunk *chunk = arg;
2107 enum sctp_disposition retval;
2108 struct sctp_chunk *err_chk_p;
2112 /* Make sure that the chunk has a valid length from the protocol
2113 * perspective. In this case check to make sure we have at least
2114 * enough for the chunk header. Cookie length verification is
2117 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
2118 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2121 /* "Decode" the chunk. We have no optional parameters so we
2122 * are in good shape.
2124 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2125 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2126 sizeof(struct sctp_chunkhdr)))
2129 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2130 * of a duplicate COOKIE ECHO match the Verification Tags of the
2131 * current association, consider the State Cookie valid even if
2132 * the lifespan is exceeded.
2134 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2138 * If the re-build failed, what is the proper error path
2141 * [We should abort the association. --piggy]
2144 /* FIXME: Several errors are possible. A bad cookie should
2145 * be silently discarded, but think about logging it too.
2148 case -SCTP_IERROR_NOMEM:
2151 case -SCTP_IERROR_STALE_COOKIE:
2152 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2154 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2155 case -SCTP_IERROR_BAD_SIG:
2157 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2161 /* Update socket peer label if first association. */
2162 if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
2164 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2166 /* Set temp so that it won't be added into hashtable */
2169 /* Compare the tie_tag in cookie with the verification tag of
2170 * current association.
2172 action = sctp_tietags_compare(new_asoc, asoc);
2175 case 'A': /* Association restart. */
2176 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2180 case 'B': /* Collision case B. */
2181 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2185 case 'C': /* Collision case C. */
2186 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2190 case 'D': /* Collision case D. */
2191 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2195 default: /* Discard packet for all others. */
2196 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2200 /* Delete the tempory new association. */
2201 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2202 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2204 /* Restore association pointer to provide SCTP command interpeter
2205 * with a valid context in case it needs to manipulate
2207 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2208 SCTP_ASOC((struct sctp_association *)asoc));
2213 return SCTP_DISPOSITION_NOMEM;
2217 * Process an ABORT. (SHUTDOWN-PENDING state)
2219 * See sctp_sf_do_9_1_abort().
2221 enum sctp_disposition sctp_sf_shutdown_pending_abort(
2223 const struct sctp_endpoint *ep,
2224 const struct sctp_association *asoc,
2225 const union sctp_subtype type,
2227 struct sctp_cmd_seq *commands)
2229 struct sctp_chunk *chunk = arg;
2231 if (!sctp_vtag_verify_either(chunk, asoc))
2232 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2234 /* Make sure that the ABORT chunk has a valid length.
2235 * Since this is an ABORT chunk, we have to discard it
2236 * because of the following text:
2237 * RFC 2960, Section 3.3.7
2238 * If an endpoint receives an ABORT with a format error or for an
2239 * association that doesn't exist, it MUST silently discard it.
2240 * Because the length is "invalid", we can't really discard just
2241 * as we do not know its true length. So, to be safe, discard the
2244 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2245 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2247 /* ADD-IP: Special case for ABORT chunks
2248 * F4) One special consideration is that ABORT Chunks arriving
2249 * destined to the IP address being deleted MUST be
2250 * ignored (see Section 5.3.1 for further details).
2252 if (SCTP_ADDR_DEL ==
2253 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2254 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2256 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2260 * Process an ABORT. (SHUTDOWN-SENT state)
2262 * See sctp_sf_do_9_1_abort().
2264 enum sctp_disposition sctp_sf_shutdown_sent_abort(
2266 const struct sctp_endpoint *ep,
2267 const struct sctp_association *asoc,
2268 const union sctp_subtype type,
2270 struct sctp_cmd_seq *commands)
2272 struct sctp_chunk *chunk = arg;
2274 if (!sctp_vtag_verify_either(chunk, asoc))
2275 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2277 /* Make sure that the ABORT chunk has a valid length.
2278 * Since this is an ABORT chunk, we have to discard it
2279 * because of the following text:
2280 * RFC 2960, Section 3.3.7
2281 * If an endpoint receives an ABORT with a format error or for an
2282 * association that doesn't exist, it MUST silently discard it.
2283 * Because the length is "invalid", we can't really discard just
2284 * as we do not know its true length. So, to be safe, discard the
2287 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2288 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2290 /* ADD-IP: Special case for ABORT chunks
2291 * F4) One special consideration is that ABORT Chunks arriving
2292 * destined to the IP address being deleted MUST be
2293 * ignored (see Section 5.3.1 for further details).
2295 if (SCTP_ADDR_DEL ==
2296 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2297 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2299 /* Stop the T2-shutdown timer. */
2300 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2301 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2303 /* Stop the T5-shutdown guard timer. */
2304 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2305 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2307 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2311 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2313 * See sctp_sf_do_9_1_abort().
2315 enum sctp_disposition sctp_sf_shutdown_ack_sent_abort(
2317 const struct sctp_endpoint *ep,
2318 const struct sctp_association *asoc,
2319 const union sctp_subtype type,
2321 struct sctp_cmd_seq *commands)
2323 /* The same T2 timer, so we should be able to use
2324 * common function with the SHUTDOWN-SENT state.
2326 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2330 * Handle an Error received in COOKIE_ECHOED state.
2332 * Only handle the error type of stale COOKIE Error, the other errors will
2336 * (endpoint, asoc, chunk)
2339 * (asoc, reply_msg, msg_up, timers, counters)
2341 * The return value is the disposition of the chunk.
2343 enum sctp_disposition sctp_sf_cookie_echoed_err(
2345 const struct sctp_endpoint *ep,
2346 const struct sctp_association *asoc,
2347 const union sctp_subtype type,
2349 struct sctp_cmd_seq *commands)
2351 struct sctp_chunk *chunk = arg;
2352 struct sctp_errhdr *err;
2354 if (!sctp_vtag_verify(chunk, asoc))
2355 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2357 /* Make sure that the ERROR chunk has a valid length.
2358 * The parameter walking depends on this as well.
2360 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
2361 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2364 /* Process the error here */
2365 /* FUTURE FIXME: When PR-SCTP related and other optional
2366 * parms are emitted, this will have to change to handle multiple
2369 sctp_walk_errors(err, chunk->chunk_hdr) {
2370 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2371 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2375 /* It is possible to have malformed error causes, and that
2376 * will cause us to end the walk early. However, since
2377 * we are discarding the packet, there should be no adverse
2380 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2384 * Handle a Stale COOKIE Error
2386 * Section: 5.2.6 Handle Stale COOKIE Error
2387 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2388 * one of the following three alternatives.
2390 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2391 * Preservative parameter requesting an extension to the lifetime of
2392 * the State Cookie. When calculating the time extension, an
2393 * implementation SHOULD use the RTT information measured based on the
2394 * previous COOKIE ECHO / ERROR exchange, and should add no more
2395 * than 1 second beyond the measured RTT, due to long State Cookie
2396 * lifetimes making the endpoint more subject to a replay attack.
2398 * Verification Tag: Not explicit, but safe to ignore.
2401 * (endpoint, asoc, chunk)
2404 * (asoc, reply_msg, msg_up, timers, counters)
2406 * The return value is the disposition of the chunk.
2408 static enum sctp_disposition sctp_sf_do_5_2_6_stale(
2410 const struct sctp_endpoint *ep,
2411 const struct sctp_association *asoc,
2412 const union sctp_subtype type,
2414 struct sctp_cmd_seq *commands)
2416 int attempts = asoc->init_err_counter + 1;
2417 struct sctp_chunk *chunk = arg, *reply;
2418 struct sctp_cookie_preserve_param bht;
2419 struct sctp_bind_addr *bp;
2420 struct sctp_errhdr *err;
2423 if (attempts > asoc->max_init_attempts) {
2424 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2425 SCTP_ERROR(ETIMEDOUT));
2426 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2427 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2428 return SCTP_DISPOSITION_DELETE_TCB;
2431 err = (struct sctp_errhdr *)(chunk->skb->data);
2433 /* When calculating the time extension, an implementation
2434 * SHOULD use the RTT information measured based on the
2435 * previous COOKIE ECHO / ERROR exchange, and should add no
2436 * more than 1 second beyond the measured RTT, due to long
2437 * State Cookie lifetimes making the endpoint more subject to
2439 * Measure of Staleness's unit is usec. (1/1000000 sec)
2440 * Suggested Cookie Life-span Increment's unit is msec.
2442 * In general, if you use the suggested cookie life, the value
2443 * found in the field of measure of staleness should be doubled
2444 * to give ample time to retransmit the new cookie and thus
2445 * yield a higher probability of success on the reattempt.
2447 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err)));
2448 stale = (stale * 2) / 1000;
2450 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2451 bht.param_hdr.length = htons(sizeof(bht));
2452 bht.lifespan_increment = htonl(stale);
2454 /* Build that new INIT chunk. */
2455 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2456 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2460 sctp_addto_chunk(reply, sizeof(bht), &bht);
2462 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2463 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2465 /* Stop pending T3-rtx and heartbeat timers */
2466 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2467 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2469 /* Delete non-primary peer ip addresses since we are transitioning
2470 * back to the COOKIE-WAIT state
2472 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2474 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2477 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2478 SCTP_TRANSPORT(asoc->peer.primary_path));
2480 /* Cast away the const modifier, as we want to just
2481 * rerun it through as a sideffect.
2483 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2485 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2486 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2487 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2488 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2489 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2490 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2492 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2494 return SCTP_DISPOSITION_CONSUME;
2497 return SCTP_DISPOSITION_NOMEM;
2504 * After checking the Verification Tag, the receiving endpoint shall
2505 * remove the association from its record, and shall report the
2506 * termination to its upper layer.
2508 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2509 * B) Rules for packet carrying ABORT:
2511 * - The endpoint shall always fill in the Verification Tag field of the
2512 * outbound packet with the destination endpoint's tag value if it
2515 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2516 * MUST follow the procedure described in Section 8.4.
2518 * - The receiver MUST accept the packet if the Verification Tag
2519 * matches either its own tag, OR the tag of its peer. Otherwise, the
2520 * receiver MUST silently discard the packet and take no further
2524 * (endpoint, asoc, chunk)
2527 * (asoc, reply_msg, msg_up, timers, counters)
2529 * The return value is the disposition of the chunk.
2531 enum sctp_disposition sctp_sf_do_9_1_abort(
2533 const struct sctp_endpoint *ep,
2534 const struct sctp_association *asoc,
2535 const union sctp_subtype type,
2537 struct sctp_cmd_seq *commands)
2539 struct sctp_chunk *chunk = arg;
2541 if (!sctp_vtag_verify_either(chunk, asoc))
2542 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2544 /* Make sure that the ABORT chunk has a valid length.
2545 * Since this is an ABORT chunk, we have to discard it
2546 * because of the following text:
2547 * RFC 2960, Section 3.3.7
2548 * If an endpoint receives an ABORT with a format error or for an
2549 * association that doesn't exist, it MUST silently discard it.
2550 * Because the length is "invalid", we can't really discard just
2551 * as we do not know its true length. So, to be safe, discard the
2554 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2555 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2557 /* ADD-IP: Special case for ABORT chunks
2558 * F4) One special consideration is that ABORT Chunks arriving
2559 * destined to the IP address being deleted MUST be
2560 * ignored (see Section 5.3.1 for further details).
2562 if (SCTP_ADDR_DEL ==
2563 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2564 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
2566 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2569 static enum sctp_disposition __sctp_sf_do_9_1_abort(
2571 const struct sctp_endpoint *ep,
2572 const struct sctp_association *asoc,
2573 const union sctp_subtype type,
2575 struct sctp_cmd_seq *commands)
2577 __be16 error = SCTP_ERROR_NO_ERROR;
2578 struct sctp_chunk *chunk = arg;
2581 /* See if we have an error cause code in the chunk. */
2582 len = ntohs(chunk->chunk_hdr->length);
2583 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2584 struct sctp_errhdr *err;
2586 sctp_walk_errors(err, chunk->chunk_hdr);
2587 if ((void *)err != (void *)chunk->chunk_end)
2588 return sctp_sf_pdiscard(net, ep, asoc, type, arg,
2591 error = ((struct sctp_errhdr *)chunk->skb->data)->cause;
2594 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2595 /* ASSOC_FAILED will DELETE_TCB. */
2596 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2597 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2598 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2600 return SCTP_DISPOSITION_ABORT;
2604 * Process an ABORT. (COOKIE-WAIT state)
2606 * See sctp_sf_do_9_1_abort() above.
2608 enum sctp_disposition sctp_sf_cookie_wait_abort(
2610 const struct sctp_endpoint *ep,
2611 const struct sctp_association *asoc,
2612 const union sctp_subtype type,
2614 struct sctp_cmd_seq *commands)
2616 __be16 error = SCTP_ERROR_NO_ERROR;
2617 struct sctp_chunk *chunk = arg;
2620 if (!sctp_vtag_verify_either(chunk, asoc))
2621 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2623 /* Make sure that the ABORT chunk has a valid length.
2624 * Since this is an ABORT chunk, we have to discard it
2625 * because of the following text:
2626 * RFC 2960, Section 3.3.7
2627 * If an endpoint receives an ABORT with a format error or for an
2628 * association that doesn't exist, it MUST silently discard it.
2629 * Because the length is "invalid", we can't really discard just
2630 * as we do not know its true length. So, to be safe, discard the
2633 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2634 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2636 /* See if we have an error cause code in the chunk. */
2637 len = ntohs(chunk->chunk_hdr->length);
2638 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2639 error = ((struct sctp_errhdr *)chunk->skb->data)->cause;
2641 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2646 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2648 enum sctp_disposition sctp_sf_cookie_wait_icmp_abort(
2650 const struct sctp_endpoint *ep,
2651 const struct sctp_association *asoc,
2652 const union sctp_subtype type,
2654 struct sctp_cmd_seq *commands)
2656 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2658 (struct sctp_transport *)arg);
2662 * Process an ABORT. (COOKIE-ECHOED state)
2664 enum sctp_disposition sctp_sf_cookie_echoed_abort(
2666 const struct sctp_endpoint *ep,
2667 const struct sctp_association *asoc,
2668 const union sctp_subtype type,
2670 struct sctp_cmd_seq *commands)
2672 /* There is a single T1 timer, so we should be able to use
2673 * common function with the COOKIE-WAIT state.
2675 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2679 * Stop T1 timer and abort association with "INIT failed".
2681 * This is common code called by several sctp_sf_*_abort() functions above.
2683 static enum sctp_disposition sctp_stop_t1_and_abort(
2685 struct sctp_cmd_seq *commands,
2686 __be16 error, int sk_err,
2687 const struct sctp_association *asoc,
2688 struct sctp_transport *transport)
2690 pr_debug("%s: ABORT received (INIT)\n", __func__);
2692 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2693 SCTP_STATE(SCTP_STATE_CLOSED));
2694 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2695 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2696 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2697 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2698 /* CMD_INIT_FAILED will DELETE_TCB. */
2699 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2702 return SCTP_DISPOSITION_ABORT;
2706 * sctp_sf_do_9_2_shut
2709 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2710 * - enter the SHUTDOWN-RECEIVED state,
2712 * - stop accepting new data from its SCTP user
2714 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2715 * that all its outstanding DATA chunks have been received by the
2718 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2719 * send a SHUTDOWN in response to a ULP request. And should discard
2720 * subsequent SHUTDOWN chunks.
2722 * If there are still outstanding DATA chunks left, the SHUTDOWN
2723 * receiver shall continue to follow normal data transmission
2724 * procedures defined in Section 6 until all outstanding DATA chunks
2725 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2726 * new data from its SCTP user.
2728 * Verification Tag: 8.5 Verification Tag [Normal verification]
2731 * (endpoint, asoc, chunk)
2734 * (asoc, reply_msg, msg_up, timers, counters)
2736 * The return value is the disposition of the chunk.
2738 enum sctp_disposition sctp_sf_do_9_2_shutdown(
2740 const struct sctp_endpoint *ep,
2741 const struct sctp_association *asoc,
2742 const union sctp_subtype type,
2744 struct sctp_cmd_seq *commands)
2746 enum sctp_disposition disposition;
2747 struct sctp_chunk *chunk = arg;
2748 struct sctp_shutdownhdr *sdh;
2749 struct sctp_ulpevent *ev;
2752 if (!sctp_vtag_verify(chunk, asoc))
2753 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2755 /* Make sure that the SHUTDOWN chunk has a valid length. */
2756 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
2757 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2760 /* Convert the elaborate header. */
2761 sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
2762 skb_pull(chunk->skb, sizeof(*sdh));
2763 chunk->subh.shutdown_hdr = sdh;
2764 ctsn = ntohl(sdh->cum_tsn_ack);
2766 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2767 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2768 asoc->ctsn_ack_point);
2770 return SCTP_DISPOSITION_DISCARD;
2773 /* If Cumulative TSN Ack beyond the max tsn currently
2774 * send, terminating the association and respond to the
2775 * sender with an ABORT.
2777 if (!TSN_lt(ctsn, asoc->next_tsn))
2778 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2780 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2781 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2782 * inform the application that it should cease sending data.
2784 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2786 disposition = SCTP_DISPOSITION_NOMEM;
2789 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2791 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2792 * - enter the SHUTDOWN-RECEIVED state,
2793 * - stop accepting new data from its SCTP user
2795 * [This is implicit in the new state.]
2797 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2798 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2799 disposition = SCTP_DISPOSITION_CONSUME;
2801 if (sctp_outq_is_empty(&asoc->outqueue)) {
2802 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2806 if (SCTP_DISPOSITION_NOMEM == disposition)
2809 /* - verify, by checking the Cumulative TSN Ack field of the
2810 * chunk, that all its outstanding DATA chunks have been
2811 * received by the SHUTDOWN sender.
2813 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2814 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2821 * sctp_sf_do_9_2_shut_ctsn
2823 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2824 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2825 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2826 * MUST be processed.
2828 enum sctp_disposition sctp_sf_do_9_2_shut_ctsn(
2830 const struct sctp_endpoint *ep,
2831 const struct sctp_association *asoc,
2832 const union sctp_subtype type,
2834 struct sctp_cmd_seq *commands)
2836 struct sctp_chunk *chunk = arg;
2837 struct sctp_shutdownhdr *sdh;
2840 if (!sctp_vtag_verify(chunk, asoc))
2841 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2843 /* Make sure that the SHUTDOWN chunk has a valid length. */
2844 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
2845 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2848 sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
2849 ctsn = ntohl(sdh->cum_tsn_ack);
2851 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2852 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2853 asoc->ctsn_ack_point);
2855 return SCTP_DISPOSITION_DISCARD;
2858 /* If Cumulative TSN Ack beyond the max tsn currently
2859 * send, terminating the association and respond to the
2860 * sender with an ABORT.
2862 if (!TSN_lt(ctsn, asoc->next_tsn))
2863 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2865 /* verify, by checking the Cumulative TSN Ack field of the
2866 * chunk, that all its outstanding DATA chunks have been
2867 * received by the SHUTDOWN sender.
2869 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2870 SCTP_BE32(sdh->cum_tsn_ack));
2872 return SCTP_DISPOSITION_CONSUME;
2876 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2877 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2878 * transport addresses (either in the IP addresses or in the INIT chunk)
2879 * that belong to this association, it should discard the INIT chunk and
2880 * retransmit the SHUTDOWN ACK chunk.
2882 enum sctp_disposition sctp_sf_do_9_2_reshutack(
2884 const struct sctp_endpoint *ep,
2885 const struct sctp_association *asoc,
2886 const union sctp_subtype type,
2888 struct sctp_cmd_seq *commands)
2890 struct sctp_chunk *chunk = arg;
2891 struct sctp_chunk *reply;
2893 /* Make sure that the chunk has a valid length */
2894 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
2895 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2898 /* Since we are not going to really process this INIT, there
2899 * is no point in verifying chunk boundries. Just generate
2902 reply = sctp_make_shutdown_ack(asoc, chunk);
2906 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2907 * the T2-SHUTDOWN timer.
2909 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2911 /* and restart the T2-shutdown timer. */
2912 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2913 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2915 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2917 return SCTP_DISPOSITION_CONSUME;
2919 return SCTP_DISPOSITION_NOMEM;
2923 * sctp_sf_do_ecn_cwr
2925 * Section: Appendix A: Explicit Congestion Notification
2929 * RFC 2481 details a specific bit for a sender to send in the header of
2930 * its next outbound TCP segment to indicate to its peer that it has
2931 * reduced its congestion window. This is termed the CWR bit. For
2932 * SCTP the same indication is made by including the CWR chunk.
2933 * This chunk contains one data element, i.e. the TSN number that
2934 * was sent in the ECNE chunk. This element represents the lowest
2935 * TSN number in the datagram that was originally marked with the
2938 * Verification Tag: 8.5 Verification Tag [Normal verification]
2940 * (endpoint, asoc, chunk)
2943 * (asoc, reply_msg, msg_up, timers, counters)
2945 * The return value is the disposition of the chunk.
2947 enum sctp_disposition sctp_sf_do_ecn_cwr(struct net *net,
2948 const struct sctp_endpoint *ep,
2949 const struct sctp_association *asoc,
2950 const union sctp_subtype type,
2952 struct sctp_cmd_seq *commands)
2954 struct sctp_chunk *chunk = arg;
2955 struct sctp_cwrhdr *cwr;
2958 if (!sctp_vtag_verify(chunk, asoc))
2959 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2961 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
2962 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2965 cwr = (struct sctp_cwrhdr *)chunk->skb->data;
2966 skb_pull(chunk->skb, sizeof(*cwr));
2968 lowest_tsn = ntohl(cwr->lowest_tsn);
2970 /* Does this CWR ack the last sent congestion notification? */
2971 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2972 /* Stop sending ECNE. */
2973 sctp_add_cmd_sf(commands,
2975 SCTP_U32(lowest_tsn));
2977 return SCTP_DISPOSITION_CONSUME;
2983 * Section: Appendix A: Explicit Congestion Notification
2987 * RFC 2481 details a specific bit for a receiver to send back in its
2988 * TCP acknowledgements to notify the sender of the Congestion
2989 * Experienced (CE) bit having arrived from the network. For SCTP this
2990 * same indication is made by including the ECNE chunk. This chunk
2991 * contains one data element, i.e. the lowest TSN associated with the IP
2992 * datagram marked with the CE bit.....
2994 * Verification Tag: 8.5 Verification Tag [Normal verification]
2996 * (endpoint, asoc, chunk)
2999 * (asoc, reply_msg, msg_up, timers, counters)
3001 * The return value is the disposition of the chunk.
3003 enum sctp_disposition sctp_sf_do_ecne(struct net *net,
3004 const struct sctp_endpoint *ep,
3005 const struct sctp_association *asoc,
3006 const union sctp_subtype type,
3007 void *arg, struct sctp_cmd_seq *commands)
3009 struct sctp_chunk *chunk = arg;
3010 struct sctp_ecnehdr *ecne;
3012 if (!sctp_vtag_verify(chunk, asoc))
3013 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3015 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
3016 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3019 ecne = (struct sctp_ecnehdr *)chunk->skb->data;
3020 skb_pull(chunk->skb, sizeof(*ecne));
3022 /* If this is a newer ECNE than the last CWR packet we sent out */
3023 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
3024 SCTP_U32(ntohl(ecne->lowest_tsn)));
3026 return SCTP_DISPOSITION_CONSUME;
3030 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
3032 * The SCTP endpoint MUST always acknowledge the reception of each valid
3035 * The guidelines on delayed acknowledgement algorithm specified in
3036 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
3037 * acknowledgement SHOULD be generated for at least every second packet
3038 * (not every second DATA chunk) received, and SHOULD be generated within
3039 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
3040 * situations it may be beneficial for an SCTP transmitter to be more
3041 * conservative than the algorithms detailed in this document allow.
3042 * However, an SCTP transmitter MUST NOT be more aggressive than the
3043 * following algorithms allow.
3045 * A SCTP receiver MUST NOT generate more than one SACK for every
3046 * incoming packet, other than to update the offered window as the
3047 * receiving application consumes new data.
3049 * Verification Tag: 8.5 Verification Tag [Normal verification]
3052 * (endpoint, asoc, chunk)
3055 * (asoc, reply_msg, msg_up, timers, counters)
3057 * The return value is the disposition of the chunk.
3059 enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net,
3060 const struct sctp_endpoint *ep,
3061 const struct sctp_association *asoc,
3062 const union sctp_subtype type,
3064 struct sctp_cmd_seq *commands)
3066 union sctp_arg force = SCTP_NOFORCE();
3067 struct sctp_chunk *chunk = arg;
3070 if (!sctp_vtag_verify(chunk, asoc)) {
3071 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3073 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3076 if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
3077 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3080 error = sctp_eat_data(asoc, chunk, commands);
3082 case SCTP_IERROR_NO_ERROR:
3084 case SCTP_IERROR_HIGH_TSN:
3085 case SCTP_IERROR_BAD_STREAM:
3086 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3087 goto discard_noforce;
3088 case SCTP_IERROR_DUP_TSN:
3089 case SCTP_IERROR_IGNORE_TSN:
3090 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3092 case SCTP_IERROR_NO_DATA:
3093 return SCTP_DISPOSITION_ABORT;
3094 case SCTP_IERROR_PROTO_VIOLATION:
3095 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3096 (u8 *)chunk->subh.data_hdr,
3097 sctp_datahdr_len(&asoc->stream));
3102 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
3103 force = SCTP_FORCE();
3105 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3106 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3107 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3110 /* If this is the last chunk in a packet, we need to count it
3111 * toward sack generation. Note that we need to SACK every
3112 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3113 * THEM. We elect to NOT generate SACK's if the chunk fails
3114 * the verification tag test.
3116 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3118 * The SCTP endpoint MUST always acknowledge the reception of
3119 * each valid DATA chunk.
3121 * The guidelines on delayed acknowledgement algorithm
3122 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3123 * Specifically, an acknowledgement SHOULD be generated for at
3124 * least every second packet (not every second DATA chunk)
3125 * received, and SHOULD be generated within 200 ms of the
3126 * arrival of any unacknowledged DATA chunk. In some
3127 * situations it may be beneficial for an SCTP transmitter to
3128 * be more conservative than the algorithms detailed in this
3129 * document allow. However, an SCTP transmitter MUST NOT be
3130 * more aggressive than the following algorithms allow.
3132 if (chunk->end_of_packet)
3133 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3135 return SCTP_DISPOSITION_CONSUME;
3138 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3140 * When a packet arrives with duplicate DATA chunk(s) and with
3141 * no new DATA chunk(s), the endpoint MUST immediately send a
3142 * SACK with no delay. If a packet arrives with duplicate
3143 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3144 * MAY immediately send a SACK. Normally receipt of duplicate
3145 * DATA chunks will occur when the original SACK chunk was lost
3146 * and the peer's RTO has expired. The duplicate TSN number(s)
3147 * SHOULD be reported in the SACK as duplicate.
3149 /* In our case, we split the MAY SACK advice up whether or not
3150 * the last chunk is a duplicate.'
3152 if (chunk->end_of_packet)
3153 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3154 return SCTP_DISPOSITION_DISCARD;
3157 if (chunk->end_of_packet)
3158 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3160 return SCTP_DISPOSITION_DISCARD;
3164 * sctp_sf_eat_data_fast_4_4
3167 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3168 * DATA chunks without delay.
3170 * Verification Tag: 8.5 Verification Tag [Normal verification]
3172 * (endpoint, asoc, chunk)
3175 * (asoc, reply_msg, msg_up, timers, counters)
3177 * The return value is the disposition of the chunk.
3179 enum sctp_disposition sctp_sf_eat_data_fast_4_4(
3181 const struct sctp_endpoint *ep,
3182 const struct sctp_association *asoc,
3183 const union sctp_subtype type,
3185 struct sctp_cmd_seq *commands)
3187 struct sctp_chunk *chunk = arg;
3190 if (!sctp_vtag_verify(chunk, asoc)) {
3191 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3193 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3196 if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
3197 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3200 error = sctp_eat_data(asoc, chunk, commands);
3202 case SCTP_IERROR_NO_ERROR:
3203 case SCTP_IERROR_HIGH_TSN:
3204 case SCTP_IERROR_DUP_TSN:
3205 case SCTP_IERROR_IGNORE_TSN:
3206 case SCTP_IERROR_BAD_STREAM:
3208 case SCTP_IERROR_NO_DATA:
3209 return SCTP_DISPOSITION_ABORT;
3210 case SCTP_IERROR_PROTO_VIOLATION:
3211 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3212 (u8 *)chunk->subh.data_hdr,
3213 sctp_datahdr_len(&asoc->stream));
3218 /* Go a head and force a SACK, since we are shutting down. */
3220 /* Implementor's Guide.
3222 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3223 * respond to each received packet containing one or more DATA chunk(s)
3224 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3226 if (chunk->end_of_packet) {
3227 /* We must delay the chunk creation since the cumulative
3228 * TSN has not been updated yet.
3230 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3231 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3232 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3233 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3236 return SCTP_DISPOSITION_CONSUME;
3240 * Section: 6.2 Processing a Received SACK
3241 * D) Any time a SACK arrives, the endpoint performs the following:
3243 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3244 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3245 * increasing, a SACK whose Cumulative TSN Ack is less than the
3246 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3248 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3249 * of bytes still outstanding after processing the Cumulative TSN Ack
3250 * and the Gap Ack Blocks.
3252 * iii) If the SACK is missing a TSN that was previously
3253 * acknowledged via a Gap Ack Block (e.g., the data receiver
3254 * reneged on the data), then mark the corresponding DATA chunk
3255 * as available for retransmit: Mark it as missing for fast
3256 * retransmit as described in Section 7.2.4 and if no retransmit
3257 * timer is running for the destination address to which the DATA
3258 * chunk was originally transmitted, then T3-rtx is started for
3259 * that destination address.
3261 * Verification Tag: 8.5 Verification Tag [Normal verification]
3264 * (endpoint, asoc, chunk)
3267 * (asoc, reply_msg, msg_up, timers, counters)
3269 * The return value is the disposition of the chunk.
3271 enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
3272 const struct sctp_endpoint *ep,
3273 const struct sctp_association *asoc,
3274 const union sctp_subtype type,
3276 struct sctp_cmd_seq *commands)
3278 struct sctp_chunk *chunk = arg;
3279 struct sctp_sackhdr *sackh;
3282 trace_sctp_probe(ep, asoc, chunk);
3284 if (!sctp_vtag_verify(chunk, asoc))
3285 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3287 /* Make sure that the SACK chunk has a valid length. */
3288 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_sack_chunk)))
3289 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3292 /* Pull the SACK chunk from the data buffer */
3293 sackh = sctp_sm_pull_sack(chunk);
3294 /* Was this a bogus SACK? */
3296 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3297 chunk->subh.sack_hdr = sackh;
3298 ctsn = ntohl(sackh->cum_tsn_ack);
3300 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3301 * Ack Point, then drop the SACK. Since Cumulative TSN
3302 * Ack is monotonically increasing, a SACK whose
3303 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3304 * Point indicates an out-of-order SACK.
3306 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3307 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3308 asoc->ctsn_ack_point);
3310 return SCTP_DISPOSITION_DISCARD;
3313 /* If Cumulative TSN Ack beyond the max tsn currently
3314 * send, terminating the association and respond to the
3315 * sender with an ABORT.
3317 if (!TSN_lt(ctsn, asoc->next_tsn))
3318 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3320 /* Return this SACK for further processing. */
3321 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3323 /* Note: We do the rest of the work on the PROCESS_SACK
3326 return SCTP_DISPOSITION_CONSUME;
3330 * Generate an ABORT in response to a packet.
3332 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3334 * 8) The receiver should respond to the sender of the OOTB packet with
3335 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3336 * MUST fill in the Verification Tag field of the outbound packet
3337 * with the value found in the Verification Tag field of the OOTB
3338 * packet and set the T-bit in the Chunk Flags to indicate that the
3339 * Verification Tag is reflected. After sending this ABORT, the
3340 * receiver of the OOTB packet shall discard the OOTB packet and take
3341 * no further action.
3345 * The return value is the disposition of the chunk.
3347 static enum sctp_disposition sctp_sf_tabort_8_4_8(
3349 const struct sctp_endpoint *ep,
3350 const struct sctp_association *asoc,
3351 const union sctp_subtype type,
3353 struct sctp_cmd_seq *commands)
3355 struct sctp_packet *packet = NULL;
3356 struct sctp_chunk *chunk = arg;
3357 struct sctp_chunk *abort;
3359 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3361 return SCTP_DISPOSITION_NOMEM;
3363 /* Make an ABORT. The T bit will be set if the asoc
3366 abort = sctp_make_abort(asoc, chunk, 0);
3368 sctp_ootb_pkt_free(packet);
3369 return SCTP_DISPOSITION_NOMEM;
3372 /* Reflect vtag if T-Bit is set */
3373 if (sctp_test_T_bit(abort))
3374 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3376 /* Set the skb to the belonging sock for accounting. */
3377 abort->skb->sk = ep->base.sk;
3379 sctp_packet_append_chunk(packet, abort);
3381 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3382 SCTP_PACKET(packet));
3384 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3386 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3387 return SCTP_DISPOSITION_CONSUME;
3391 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3392 * event as ULP notification for each cause included in the chunk.
3394 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3396 * The return value is the disposition of the chunk.
3398 enum sctp_disposition sctp_sf_operr_notify(struct net *net,
3399 const struct sctp_endpoint *ep,
3400 const struct sctp_association *asoc,
3401 const union sctp_subtype type,
3403 struct sctp_cmd_seq *commands)
3405 struct sctp_chunk *chunk = arg;
3406 struct sctp_errhdr *err;
3408 if (!sctp_vtag_verify(chunk, asoc))
3409 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3411 /* Make sure that the ERROR chunk has a valid length. */
3412 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
3413 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3415 sctp_walk_errors(err, chunk->chunk_hdr);
3416 if ((void *)err != (void *)chunk->chunk_end)
3417 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3418 (void *)err, commands);
3420 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3423 return SCTP_DISPOSITION_CONSUME;
3427 * Process an inbound SHUTDOWN ACK.
3430 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3431 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3432 * peer, and remove all record of the association.
3434 * The return value is the disposition.
3436 enum sctp_disposition sctp_sf_do_9_2_final(struct net *net,
3437 const struct sctp_endpoint *ep,
3438 const struct sctp_association *asoc,
3439 const union sctp_subtype type,
3441 struct sctp_cmd_seq *commands)
3443 struct sctp_chunk *chunk = arg;
3444 struct sctp_chunk *reply;
3445 struct sctp_ulpevent *ev;
3447 if (!sctp_vtag_verify(chunk, asoc))
3448 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3450 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3451 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
3452 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3454 /* 10.2 H) SHUTDOWN COMPLETE notification
3456 * When SCTP completes the shutdown procedures (section 9.2) this
3457 * notification is passed to the upper layer.
3459 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3460 0, 0, 0, NULL, GFP_ATOMIC);
3464 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3465 reply = sctp_make_shutdown_complete(asoc, chunk);
3469 /* Do all the commands now (after allocation), so that we
3470 * have consistent state if memory allocation failes
3472 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3474 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3475 * stop the T2-shutdown timer,
3477 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3478 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3480 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3481 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3483 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3484 SCTP_STATE(SCTP_STATE_CLOSED));
3485 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3486 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3487 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3489 /* ...and remove all record of the association. */
3490 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3491 return SCTP_DISPOSITION_DELETE_TCB;
3494 sctp_ulpevent_free(ev);
3496 return SCTP_DISPOSITION_NOMEM;
3500 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3502 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3503 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3504 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3505 * packet must fill in the Verification Tag field of the outbound
3506 * packet with the Verification Tag received in the SHUTDOWN ACK and
3507 * set the T-bit in the Chunk Flags to indicate that the Verification
3510 * 8) The receiver should respond to the sender of the OOTB packet with
3511 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3512 * MUST fill in the Verification Tag field of the outbound packet
3513 * with the value found in the Verification Tag field of the OOTB
3514 * packet and set the T-bit in the Chunk Flags to indicate that the
3515 * Verification Tag is reflected. After sending this ABORT, the
3516 * receiver of the OOTB packet shall discard the OOTB packet and take
3517 * no further action.
3519 enum sctp_disposition sctp_sf_ootb(struct net *net,
3520 const struct sctp_endpoint *ep,
3521 const struct sctp_association *asoc,
3522 const union sctp_subtype type,
3523 void *arg, struct sctp_cmd_seq *commands)
3525 struct sctp_chunk *chunk = arg;
3526 struct sk_buff *skb = chunk->skb;
3527 struct sctp_chunkhdr *ch;
3528 struct sctp_errhdr *err;
3529 int ootb_cookie_ack = 0;
3530 int ootb_shut_ack = 0;
3533 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3535 ch = (struct sctp_chunkhdr *)chunk->chunk_hdr;
3537 /* Report violation if the chunk is less then minimal */
3538 if (ntohs(ch->length) < sizeof(*ch))
3539 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3542 /* Report violation if chunk len overflows */
3543 ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
3544 if (ch_end > skb_tail_pointer(skb))
3545 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3548 /* Now that we know we at least have a chunk header,
3549 * do things that are type appropriate.
3551 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3554 /* RFC 2960, Section 3.3.7
3555 * Moreover, under any circumstances, an endpoint that
3556 * receives an ABORT MUST NOT respond to that ABORT by
3557 * sending an ABORT of its own.
3559 if (SCTP_CID_ABORT == ch->type)
3560 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3562 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3563 * or a COOKIE ACK the SCTP Packet should be silently
3567 if (SCTP_CID_COOKIE_ACK == ch->type)
3568 ootb_cookie_ack = 1;
3570 if (SCTP_CID_ERROR == ch->type) {
3571 sctp_walk_errors(err, ch) {
3572 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3573 ootb_cookie_ack = 1;
3579 ch = (struct sctp_chunkhdr *)ch_end;
3580 } while (ch_end < skb_tail_pointer(skb));
3583 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3584 else if (ootb_cookie_ack)
3585 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3587 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3591 * Handle an "Out of the blue" SHUTDOWN ACK.
3593 * Section: 8.4 5, sctpimpguide 2.41.
3595 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3596 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3597 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3598 * packet must fill in the Verification Tag field of the outbound
3599 * packet with the Verification Tag received in the SHUTDOWN ACK and
3600 * set the T-bit in the Chunk Flags to indicate that the Verification
3604 * (endpoint, asoc, type, arg, commands)
3607 * (enum sctp_disposition)
3609 * The return value is the disposition of the chunk.
3611 static enum sctp_disposition sctp_sf_shut_8_4_5(
3613 const struct sctp_endpoint *ep,
3614 const struct sctp_association *asoc,
3615 const union sctp_subtype type,
3617 struct sctp_cmd_seq *commands)
3619 struct sctp_packet *packet = NULL;
3620 struct sctp_chunk *chunk = arg;
3621 struct sctp_chunk *shut;
3623 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3625 return SCTP_DISPOSITION_NOMEM;
3627 /* Make an SHUTDOWN_COMPLETE.
3628 * The T bit will be set if the asoc is NULL.
3630 shut = sctp_make_shutdown_complete(asoc, chunk);
3632 sctp_ootb_pkt_free(packet);
3633 return SCTP_DISPOSITION_NOMEM;
3636 /* Reflect vtag if T-Bit is set */
3637 if (sctp_test_T_bit(shut))
3638 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3640 /* Set the skb to the belonging sock for accounting. */
3641 shut->skb->sk = ep->base.sk;
3643 sctp_packet_append_chunk(packet, shut);
3645 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3646 SCTP_PACKET(packet));
3648 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3650 /* If the chunk length is invalid, we don't want to process
3651 * the reset of the packet.
3653 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
3654 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3656 /* We need to discard the rest of the packet to prevent
3657 * potential bomming attacks from additional bundled chunks.
3658 * This is documented in SCTP Threats ID.
3660 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3664 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3666 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3667 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3668 * procedures in section 8.4 SHOULD be followed, in other words it
3669 * should be treated as an Out Of The Blue packet.
3670 * [This means that we do NOT check the Verification Tag on these
3674 enum sctp_disposition sctp_sf_do_8_5_1_E_sa(struct net *net,
3675 const struct sctp_endpoint *ep,
3676 const struct sctp_association *asoc,
3677 const union sctp_subtype type,
3679 struct sctp_cmd_seq *commands)
3681 struct sctp_chunk *chunk = arg;
3683 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3684 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
3685 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3688 /* Although we do have an association in this case, it corresponds
3689 * to a restarted association. So the packet is treated as an OOTB
3690 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3691 * called with a NULL association.
3693 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3695 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3698 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3699 enum sctp_disposition sctp_sf_do_asconf(struct net *net,
3700 const struct sctp_endpoint *ep,
3701 const struct sctp_association *asoc,
3702 const union sctp_subtype type,
3704 struct sctp_cmd_seq *commands)
3706 struct sctp_paramhdr *err_param = NULL;
3707 struct sctp_chunk *asconf_ack = NULL;
3708 struct sctp_chunk *chunk = arg;
3709 struct sctp_addiphdr *hdr;
3712 if (!sctp_vtag_verify(chunk, asoc)) {
3713 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3715 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3718 /* ADD-IP: Section 4.1.1
3719 * This chunk MUST be sent in an authenticated way by using
3720 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3721 * is received unauthenticated it MUST be silently discarded as
3722 * described in [I-D.ietf-tsvwg-sctp-auth].
3724 if (!net->sctp.addip_noauth && !chunk->auth)
3725 return sctp_sf_discard_chunk(net, ep, asoc, type, arg,
3728 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3729 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk)))
3730 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3733 hdr = (struct sctp_addiphdr *)chunk->skb->data;
3734 serial = ntohl(hdr->serial);
3736 /* Verify the ASCONF chunk before processing it. */
3737 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
3738 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3739 (void *)err_param, commands);
3741 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3742 * the endpoint stored in a new association variable
3743 * 'Peer-Serial-Number'.
3745 if (serial == asoc->peer.addip_serial + 1) {
3746 /* If this is the first instance of ASCONF in the packet,
3747 * we can clean our old ASCONF-ACKs.
3749 if (!chunk->has_asconf)
3750 sctp_assoc_clean_asconf_ack_cache(asoc);
3752 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3753 * expected, process the ASCONF as described below and after
3754 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3755 * the response packet and cache a copy of it (in the event it
3756 * later needs to be retransmitted).
3758 * Essentially, do V1-V5.
3760 asconf_ack = sctp_process_asconf((struct sctp_association *)
3763 return SCTP_DISPOSITION_NOMEM;
3764 } else if (serial < asoc->peer.addip_serial + 1) {
3766 * If the value found in the Sequence Number is less than the
3767 * ('Peer- Sequence-Number' + 1), simply skip to the next
3768 * ASCONF, and include in the outbound response packet
3769 * any previously cached ASCONF-ACK response that was
3770 * sent and saved that matches the Sequence Number of the
3771 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3772 * Chunk exists. This will occur when an older ASCONF
3773 * arrives out of order. In such a case, the receiver
3774 * should skip the ASCONF Chunk and not include ASCONF-ACK
3775 * Chunk for that chunk.
3777 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3779 return SCTP_DISPOSITION_DISCARD;
3781 /* Reset the transport so that we select the correct one
3782 * this time around. This is to make sure that we don't
3783 * accidentally use a stale transport that's been removed.
3785 asconf_ack->transport = NULL;
3787 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3788 * it must be either a stale packet or from an attacker.
3790 return SCTP_DISPOSITION_DISCARD;
3793 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3794 * containing the ASCONF-ACK Chunks MUST be the source address of
3795 * the SCTP packet that held the ASCONF Chunks.
3797 * To do this properly, we'll set the destination address of the chunk
3798 * and at the transmit time, will try look up the transport to use.
3799 * Since ASCONFs may be bundled, the correct transport may not be
3800 * created until we process the entire packet, thus this workaround.
3802 asconf_ack->dest = chunk->source;
3803 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3804 if (asoc->new_transport) {
3805 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3806 ((struct sctp_association *)asoc)->new_transport = NULL;
3809 return SCTP_DISPOSITION_CONSUME;
3813 * ADDIP Section 4.3 General rules for address manipulation
3814 * When building TLV parameters for the ASCONF Chunk that will add or
3815 * delete IP addresses the D0 to D13 rules should be applied:
3817 enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net,
3818 const struct sctp_endpoint *ep,
3819 const struct sctp_association *asoc,
3820 const union sctp_subtype type,
3822 struct sctp_cmd_seq *commands)
3824 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3825 struct sctp_paramhdr *err_param = NULL;
3826 struct sctp_chunk *asconf_ack = arg;
3827 struct sctp_addiphdr *addip_hdr;
3828 __u32 sent_serial, rcvd_serial;
3829 struct sctp_chunk *abort;
3831 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3832 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3834 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3837 /* ADD-IP, Section 4.1.2:
3838 * This chunk MUST be sent in an authenticated way by using
3839 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3840 * is received unauthenticated it MUST be silently discarded as
3841 * described in [I-D.ietf-tsvwg-sctp-auth].
3843 if (!net->sctp.addip_noauth && !asconf_ack->auth)
3844 return sctp_sf_discard_chunk(net, ep, asoc, type, arg,
3847 /* Make sure that the ADDIP chunk has a valid length. */
3848 if (!sctp_chunk_length_valid(asconf_ack,
3849 sizeof(struct sctp_addip_chunk)))
3850 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3853 addip_hdr = (struct sctp_addiphdr *)asconf_ack->skb->data;
3854 rcvd_serial = ntohl(addip_hdr->serial);
3856 /* Verify the ASCONF-ACK chunk before processing it. */
3857 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
3858 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3859 (void *)err_param, commands);
3862 addip_hdr = (struct sctp_addiphdr *)last_asconf->subh.addip_hdr;
3863 sent_serial = ntohl(addip_hdr->serial);
3865 sent_serial = asoc->addip_serial - 1;
3868 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3869 * equal to the next serial number to be used but no ASCONF chunk is
3870 * outstanding the endpoint MUST ABORT the association. Note that a
3871 * sequence number is greater than if it is no more than 2^^31-1
3872 * larger than the current sequence number (using serial arithmetic).
3874 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3875 !(asoc->addip_last_asconf)) {
3876 abort = sctp_make_abort(asoc, asconf_ack,
3877 sizeof(struct sctp_errhdr));
3879 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3880 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3883 /* We are going to ABORT, so we might as well stop
3884 * processing the rest of the chunks in the packet.
3886 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3887 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3888 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3889 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3890 SCTP_ERROR(ECONNABORTED));
3891 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3892 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3893 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3894 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3895 return SCTP_DISPOSITION_ABORT;
3898 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3899 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3900 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3902 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3904 /* Successfully processed ASCONF_ACK. We can
3905 * release the next asconf if we have one.
3907 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3909 return SCTP_DISPOSITION_CONSUME;
3912 abort = sctp_make_abort(asoc, asconf_ack,
3913 sizeof(struct sctp_errhdr));
3915 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3916 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3919 /* We are going to ABORT, so we might as well stop
3920 * processing the rest of the chunks in the packet.
3922 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3923 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3924 SCTP_ERROR(ECONNABORTED));
3925 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3926 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3927 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3928 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3929 return SCTP_DISPOSITION_ABORT;
3932 return SCTP_DISPOSITION_DISCARD;
3935 /* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
3936 enum sctp_disposition sctp_sf_do_reconf(struct net *net,
3937 const struct sctp_endpoint *ep,
3938 const struct sctp_association *asoc,
3939 const union sctp_subtype type,
3941 struct sctp_cmd_seq *commands)
3943 struct sctp_paramhdr *err_param = NULL;
3944 struct sctp_chunk *chunk = arg;
3945 struct sctp_reconf_chunk *hdr;
3946 union sctp_params param;
3948 if (!sctp_vtag_verify(chunk, asoc)) {
3949 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3951 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3954 /* Make sure that the RECONF chunk has a valid length. */
3955 if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
3956 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3959 if (!sctp_verify_reconf(asoc, chunk, &err_param))
3960 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3961 (void *)err_param, commands);
3963 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3964 sctp_walk_params(param, hdr, params) {
3965 struct sctp_chunk *reply = NULL;
3966 struct sctp_ulpevent *ev = NULL;
3968 if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
3969 reply = sctp_process_strreset_outreq(
3970 (struct sctp_association *)asoc, param, &ev);
3971 else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
3972 reply = sctp_process_strreset_inreq(
3973 (struct sctp_association *)asoc, param, &ev);
3974 else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
3975 reply = sctp_process_strreset_tsnreq(
3976 (struct sctp_association *)asoc, param, &ev);
3977 else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
3978 reply = sctp_process_strreset_addstrm_out(
3979 (struct sctp_association *)asoc, param, &ev);
3980 else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
3981 reply = sctp_process_strreset_addstrm_in(
3982 (struct sctp_association *)asoc, param, &ev);
3983 else if (param.p->type == SCTP_PARAM_RESET_RESPONSE)
3984 reply = sctp_process_strreset_resp(
3985 (struct sctp_association *)asoc, param, &ev);
3988 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3992 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3996 return SCTP_DISPOSITION_CONSUME;
4000 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
4002 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
4003 * its cumulative TSN point to the value carried in the FORWARD TSN
4004 * chunk, and then MUST further advance its cumulative TSN point locally
4006 * After the above processing, the data receiver MUST stop reporting any
4007 * missing TSNs earlier than or equal to the new cumulative TSN point.
4009 * Verification Tag: 8.5 Verification Tag [Normal verification]
4011 * The return value is the disposition of the chunk.
4013 enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
4014 const struct sctp_endpoint *ep,
4015 const struct sctp_association *asoc,
4016 const union sctp_subtype type,
4018 struct sctp_cmd_seq *commands)
4020 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
4021 struct sctp_chunk *chunk = arg;
4025 if (!sctp_vtag_verify(chunk, asoc)) {
4026 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4028 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4031 if (!asoc->peer.prsctp_capable)
4032 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4034 /* Make sure that the FORWARD_TSN chunk has valid length. */
4035 if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
4036 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4039 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4040 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4041 len = ntohs(chunk->chunk_hdr->length);
4042 len -= sizeof(struct sctp_chunkhdr);
4043 skb_pull(chunk->skb, len);
4045 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
4046 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
4048 /* The TSN is too high--silently discard the chunk and count on it
4049 * getting retransmitted later.
4051 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4052 goto discard_noforce;
4054 if (!asoc->stream.si->validate_ftsn(chunk))
4055 goto discard_noforce;
4057 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4058 if (len > sctp_ftsnhdr_len(&asoc->stream))
4059 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
4062 /* Count this as receiving DATA. */
4063 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
4064 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4065 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4068 /* FIXME: For now send a SACK, but DATA processing may
4071 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
4073 return SCTP_DISPOSITION_CONSUME;
4076 return SCTP_DISPOSITION_DISCARD;
4079 enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
4081 const struct sctp_endpoint *ep,
4082 const struct sctp_association *asoc,
4083 const union sctp_subtype type,
4085 struct sctp_cmd_seq *commands)
4087 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
4088 struct sctp_chunk *chunk = arg;
4092 if (!sctp_vtag_verify(chunk, asoc)) {
4093 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4095 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4098 if (!asoc->peer.prsctp_capable)
4099 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4101 /* Make sure that the FORWARD_TSN chunk has a valid length. */
4102 if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
4103 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4106 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4107 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4108 len = ntohs(chunk->chunk_hdr->length);
4109 len -= sizeof(struct sctp_chunkhdr);
4110 skb_pull(chunk->skb, len);
4112 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
4113 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
4115 /* The TSN is too high--silently discard the chunk and count on it
4116 * getting retransmitted later.
4118 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4121 if (!asoc->stream.si->validate_ftsn(chunk))
4124 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4125 if (len > sctp_ftsnhdr_len(&asoc->stream))
4126 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
4129 /* Go a head and force a SACK, since we are shutting down. */
4131 /* Implementor's Guide.
4133 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
4134 * respond to each received packet containing one or more DATA chunk(s)
4135 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
4137 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
4138 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4139 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4140 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4142 return SCTP_DISPOSITION_CONSUME;
4146 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
4148 * The receiver MUST use the HMAC algorithm indicated in the HMAC
4149 * Identifier field. If this algorithm was not specified by the
4150 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
4151 * during association setup, the AUTH chunk and all chunks after it MUST
4152 * be discarded and an ERROR chunk SHOULD be sent with the error cause
4153 * defined in Section 4.1.
4155 * If an endpoint with no shared key receives a Shared Key Identifier
4156 * other than 0, it MUST silently discard all authenticated chunks. If
4157 * the endpoint has at least one endpoint pair shared key for the peer,
4158 * it MUST use the key specified by the Shared Key Identifier if a
4159 * key has been configured for that Shared Key Identifier. If no
4160 * endpoint pair shared key has been configured for that Shared Key
4161 * Identifier, all authenticated chunks MUST be silently discarded.
4163 * Verification Tag: 8.5 Verification Tag [Normal verification]
4165 * The return value is the disposition of the chunk.
4167 static enum sctp_ierror sctp_sf_authenticate(
4169 const struct sctp_endpoint *ep,
4170 const struct sctp_association *asoc,
4171 const union sctp_subtype type,
4172 struct sctp_chunk *chunk)
4174 struct sctp_shared_key *sh_key = NULL;
4175 struct sctp_authhdr *auth_hdr;
4176 __u8 *save_digest, *digest;
4177 struct sctp_hmac *hmac;
4178 unsigned int sig_len;
4181 /* Pull in the auth header, so we can do some more verification */
4182 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4183 chunk->subh.auth_hdr = auth_hdr;
4184 skb_pull(chunk->skb, sizeof(*auth_hdr));
4186 /* Make sure that we support the HMAC algorithm from the auth
4189 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4190 return SCTP_IERROR_AUTH_BAD_HMAC;
4192 /* Make sure that the provided shared key identifier has been
4195 key_id = ntohs(auth_hdr->shkey_id);
4196 if (key_id != asoc->active_key_id) {
4197 sh_key = sctp_auth_get_shkey(asoc, key_id);
4199 return SCTP_IERROR_AUTH_BAD_KEYID;
4202 /* Make sure that the length of the signature matches what
4205 sig_len = ntohs(chunk->chunk_hdr->length) -
4206 sizeof(struct sctp_auth_chunk);
4207 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4208 if (sig_len != hmac->hmac_len)
4209 return SCTP_IERROR_PROTO_VIOLATION;
4211 /* Now that we've done validation checks, we can compute and
4212 * verify the hmac. The steps involved are:
4213 * 1. Save the digest from the chunk.
4214 * 2. Zero out the digest in the chunk.
4215 * 3. Compute the new digest
4216 * 4. Compare saved and new digests.
4218 digest = auth_hdr->hmac;
4219 skb_pull(chunk->skb, sig_len);
4221 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4225 memset(digest, 0, sig_len);
4227 sctp_auth_calculate_hmac(asoc, chunk->skb,
4228 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4229 sh_key, GFP_ATOMIC);
4231 /* Discard the packet if the digests do not match */
4232 if (memcmp(save_digest, digest, sig_len)) {
4234 return SCTP_IERROR_BAD_SIG;
4240 return SCTP_IERROR_NO_ERROR;
4242 return SCTP_IERROR_NOMEM;
4245 enum sctp_disposition sctp_sf_eat_auth(struct net *net,
4246 const struct sctp_endpoint *ep,
4247 const struct sctp_association *asoc,
4248 const union sctp_subtype type,
4249 void *arg, struct sctp_cmd_seq *commands)
4251 struct sctp_chunk *chunk = arg;
4252 struct sctp_authhdr *auth_hdr;
4253 struct sctp_chunk *err_chunk;
4254 enum sctp_ierror error;
4256 /* Make sure that the peer has AUTH capable */
4257 if (!asoc->peer.auth_capable)
4258 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4260 if (!sctp_vtag_verify(chunk, asoc)) {
4261 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4263 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4266 /* Make sure that the AUTH chunk has valid length. */
4267 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4268 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4271 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4272 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
4274 case SCTP_IERROR_AUTH_BAD_HMAC:
4275 /* Generate the ERROR chunk and discard the rest
4278 err_chunk = sctp_make_op_error(asoc, chunk,
4279 SCTP_ERROR_UNSUP_HMAC,
4283 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4284 SCTP_CHUNK(err_chunk));
4287 case SCTP_IERROR_AUTH_BAD_KEYID:
4288 case SCTP_IERROR_BAD_SIG:
4289 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4291 case SCTP_IERROR_PROTO_VIOLATION:
4292 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4295 case SCTP_IERROR_NOMEM:
4296 return SCTP_DISPOSITION_NOMEM;
4298 default: /* Prevent gcc warnings */
4302 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4303 struct sctp_ulpevent *ev;
4305 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4306 SCTP_AUTH_NEW_KEY, GFP_ATOMIC);
4311 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4315 return SCTP_DISPOSITION_CONSUME;
4319 * Process an unknown chunk.
4321 * Section: 3.2. Also, 2.1 in the implementor's guide.
4323 * Chunk Types are encoded such that the highest-order two bits specify
4324 * the action that must be taken if the processing endpoint does not
4325 * recognize the Chunk Type.
4327 * 00 - Stop processing this SCTP packet and discard it, do not process
4328 * any further chunks within it.
4330 * 01 - Stop processing this SCTP packet and discard it, do not process
4331 * any further chunks within it, and report the unrecognized
4332 * chunk in an 'Unrecognized Chunk Type'.
4334 * 10 - Skip this chunk and continue processing.
4336 * 11 - Skip this chunk and continue processing, but report in an ERROR
4337 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4339 * The return value is the disposition of the chunk.
4341 enum sctp_disposition sctp_sf_unk_chunk(struct net *net,
4342 const struct sctp_endpoint *ep,
4343 const struct sctp_association *asoc,
4344 const union sctp_subtype type,
4346 struct sctp_cmd_seq *commands)
4348 struct sctp_chunk *unk_chunk = arg;
4349 struct sctp_chunk *err_chunk;
4350 struct sctp_chunkhdr *hdr;
4352 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4354 if (!sctp_vtag_verify(unk_chunk, asoc))
4355 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4357 /* Make sure that the chunk has a valid length.
4358 * Since we don't know the chunk type, we use a general
4359 * chunkhdr structure to make a comparison.
4361 if (!sctp_chunk_length_valid(unk_chunk, sizeof(*hdr)))
4362 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4365 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4366 case SCTP_CID_ACTION_DISCARD:
4367 /* Discard the packet. */
4368 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4369 case SCTP_CID_ACTION_DISCARD_ERR:
4370 /* Generate an ERROR chunk as response. */
4371 hdr = unk_chunk->chunk_hdr;
4372 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4373 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4374 SCTP_PAD4(ntohs(hdr->length)),
4377 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4378 SCTP_CHUNK(err_chunk));
4381 /* Discard the packet. */
4382 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4383 return SCTP_DISPOSITION_CONSUME;
4384 case SCTP_CID_ACTION_SKIP:
4385 /* Skip the chunk. */
4386 return SCTP_DISPOSITION_DISCARD;
4387 case SCTP_CID_ACTION_SKIP_ERR:
4388 /* Generate an ERROR chunk as response. */
4389 hdr = unk_chunk->chunk_hdr;
4390 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4391 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4392 SCTP_PAD4(ntohs(hdr->length)),
4395 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4396 SCTP_CHUNK(err_chunk));
4398 /* Skip the chunk. */
4399 return SCTP_DISPOSITION_CONSUME;
4404 return SCTP_DISPOSITION_DISCARD;
4408 * Discard the chunk.
4410 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4411 * [Too numerous to mention...]
4412 * Verification Tag: No verification needed.
4414 * (endpoint, asoc, chunk)
4417 * (asoc, reply_msg, msg_up, timers, counters)
4419 * The return value is the disposition of the chunk.
4421 enum sctp_disposition sctp_sf_discard_chunk(struct net *net,
4422 const struct sctp_endpoint *ep,
4423 const struct sctp_association *asoc,
4424 const union sctp_subtype type,
4426 struct sctp_cmd_seq *commands)
4428 struct sctp_chunk *chunk = arg;
4430 /* Make sure that the chunk has a valid length.
4431 * Since we don't know the chunk type, we use a general
4432 * chunkhdr structure to make a comparison.
4434 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
4435 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4438 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4440 return SCTP_DISPOSITION_DISCARD;
4444 * Discard the whole packet.
4448 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4449 * silently discard the OOTB packet and take no further action.
4451 * Verification Tag: No verification necessary
4454 * (endpoint, asoc, chunk)
4457 * (asoc, reply_msg, msg_up, timers, counters)
4459 * The return value is the disposition of the chunk.
4461 enum sctp_disposition sctp_sf_pdiscard(struct net *net,
4462 const struct sctp_endpoint *ep,
4463 const struct sctp_association *asoc,
4464 const union sctp_subtype type,
4465 void *arg, struct sctp_cmd_seq *commands)
4467 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4468 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4470 return SCTP_DISPOSITION_CONSUME;
4475 * The other end is violating protocol.
4477 * Section: Not specified
4478 * Verification Tag: Not specified
4480 * (endpoint, asoc, chunk)
4483 * (asoc, reply_msg, msg_up, timers, counters)
4485 * We simply tag the chunk as a violation. The state machine will log
4486 * the violation and continue.
4488 enum sctp_disposition sctp_sf_violation(struct net *net,
4489 const struct sctp_endpoint *ep,
4490 const struct sctp_association *asoc,
4491 const union sctp_subtype type,
4493 struct sctp_cmd_seq *commands)
4495 struct sctp_chunk *chunk = arg;
4497 /* Make sure that the chunk has a valid length. */
4498 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
4499 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4502 return SCTP_DISPOSITION_VIOLATION;
4506 * Common function to handle a protocol violation.
4508 static enum sctp_disposition sctp_sf_abort_violation(
4510 const struct sctp_endpoint *ep,
4511 const struct sctp_association *asoc,
4513 struct sctp_cmd_seq *commands,
4514 const __u8 *payload,
4515 const size_t paylen)
4517 struct sctp_packet *packet = NULL;
4518 struct sctp_chunk *chunk = arg;
4519 struct sctp_chunk *abort = NULL;
4521 /* SCTP-AUTH, Section 6.3:
4522 * It should be noted that if the receiver wants to tear
4523 * down an association in an authenticated way only, the
4524 * handling of malformed packets should not result in
4525 * tearing down the association.
4527 * This means that if we only want to abort associations
4528 * in an authenticated way (i.e AUTH+ABORT), then we
4529 * can't destroy this association just because the packet
4532 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4535 /* Make the abort chunk. */
4536 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4541 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4542 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4543 !asoc->peer.i.init_tag) {
4544 struct sctp_initack_chunk *initack;
4546 initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
4547 if (!sctp_chunk_length_valid(chunk, sizeof(*initack)))
4548 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4550 unsigned int inittag;
4552 inittag = ntohl(initack->init_hdr.init_tag);
4553 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4558 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4559 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4561 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4562 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4563 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4564 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4565 SCTP_ERROR(ECONNREFUSED));
4566 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4567 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4569 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4570 SCTP_ERROR(ECONNABORTED));
4571 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4572 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4573 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4576 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4581 if (sctp_test_T_bit(abort))
4582 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4584 abort->skb->sk = ep->base.sk;
4586 sctp_packet_append_chunk(packet, abort);
4588 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4589 SCTP_PACKET(packet));
4591 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4594 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4597 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4598 return SCTP_DISPOSITION_ABORT;
4601 sctp_chunk_free(abort);
4603 return SCTP_DISPOSITION_NOMEM;
4607 * Handle a protocol violation when the chunk length is invalid.
4608 * "Invalid" length is identified as smaller than the minimal length a
4609 * given chunk can be. For example, a SACK chunk has invalid length
4610 * if its length is set to be smaller than the size of struct sctp_sack_chunk.
4612 * We inform the other end by sending an ABORT with a Protocol Violation
4615 * Section: Not specified
4616 * Verification Tag: Nothing to do
4618 * (endpoint, asoc, chunk)
4621 * (reply_msg, msg_up, counters)
4623 * Generate an ABORT chunk and terminate the association.
4625 static enum sctp_disposition sctp_sf_violation_chunklen(
4627 const struct sctp_endpoint *ep,
4628 const struct sctp_association *asoc,
4629 const union sctp_subtype type,
4631 struct sctp_cmd_seq *commands)
4633 static const char err_str[] = "The following chunk had invalid length:";
4635 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4640 * Handle a protocol violation when the parameter length is invalid.
4641 * If the length is smaller than the minimum length of a given parameter,
4642 * or accumulated length in multi parameters exceeds the end of the chunk,
4643 * the length is considered as invalid.
4645 static enum sctp_disposition sctp_sf_violation_paramlen(
4647 const struct sctp_endpoint *ep,
4648 const struct sctp_association *asoc,
4649 const union sctp_subtype type,
4650 void *arg, void *ext,
4651 struct sctp_cmd_seq *commands)
4653 struct sctp_paramhdr *param = ext;
4654 struct sctp_chunk *abort = NULL;
4655 struct sctp_chunk *chunk = arg;
4657 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4660 /* Make the abort chunk. */
4661 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4665 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4666 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4668 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4669 SCTP_ERROR(ECONNABORTED));
4670 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4671 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4672 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4673 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4676 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4677 return SCTP_DISPOSITION_ABORT;
4679 return SCTP_DISPOSITION_NOMEM;
4682 /* Handle a protocol violation when the peer trying to advance the
4683 * cumulative tsn ack to a point beyond the max tsn currently sent.
4685 * We inform the other end by sending an ABORT with a Protocol Violation
4688 static enum sctp_disposition sctp_sf_violation_ctsn(
4690 const struct sctp_endpoint *ep,
4691 const struct sctp_association *asoc,
4692 const union sctp_subtype type,
4694 struct sctp_cmd_seq *commands)
4696 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4698 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4702 /* Handle protocol violation of an invalid chunk bundling. For example,
4703 * when we have an association and we receive bundled INIT-ACK, or
4704 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4705 * statement from the specs. Additionally, there might be an attacker
4706 * on the path and we may not want to continue this communication.
4708 static enum sctp_disposition sctp_sf_violation_chunk(
4710 const struct sctp_endpoint *ep,
4711 const struct sctp_association *asoc,
4712 const union sctp_subtype type,
4714 struct sctp_cmd_seq *commands)
4716 static const char err_str[] = "The following chunk violates protocol:";
4719 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
4721 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4724 /***************************************************************************
4725 * These are the state functions for handling primitive (Section 10) events.
4726 ***************************************************************************/
4728 * sctp_sf_do_prm_asoc
4730 * Section: 10.1 ULP-to-SCTP
4733 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4734 * outbound stream count)
4735 * -> association id [,destination transport addr list] [,outbound stream
4738 * This primitive allows the upper layer to initiate an association to a
4739 * specific peer endpoint.
4741 * The peer endpoint shall be specified by one of the transport addresses
4742 * which defines the endpoint (see Section 1.4). If the local SCTP
4743 * instance has not been initialized, the ASSOCIATE is considered an
4745 * [This is not relevant for the kernel implementation since we do all
4746 * initialization at boot time. It we hadn't initialized we wouldn't
4747 * get anywhere near this code.]
4749 * An association id, which is a local handle to the SCTP association,
4750 * will be returned on successful establishment of the association. If
4751 * SCTP is not able to open an SCTP association with the peer endpoint,
4752 * an error is returned.
4753 * [In the kernel implementation, the struct sctp_association needs to
4754 * be created BEFORE causing this primitive to run.]
4756 * Other association parameters may be returned, including the
4757 * complete destination transport addresses of the peer as well as the
4758 * outbound stream count of the local endpoint. One of the transport
4759 * address from the returned destination addresses will be selected by
4760 * the local endpoint as default primary path for sending SCTP packets
4761 * to this peer. The returned "destination transport addr list" can
4762 * be used by the ULP to change the default primary path or to force
4763 * sending a packet to a specific transport address. [All of this
4764 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4767 * Mandatory attributes:
4769 * o local SCTP instance name - obtained from the INITIALIZE operation.
4770 * [This is the argument asoc.]
4771 * o destination transport addr - specified as one of the transport
4772 * addresses of the peer endpoint with which the association is to be
4774 * [This is asoc->peer.active_path.]
4775 * o outbound stream count - the number of outbound streams the ULP
4776 * would like to open towards this peer endpoint.
4777 * [BUG: This is not currently implemented.]
4778 * Optional attributes:
4782 * The return value is a disposition.
4784 enum sctp_disposition sctp_sf_do_prm_asoc(struct net *net,
4785 const struct sctp_endpoint *ep,
4786 const struct sctp_association *asoc,
4787 const union sctp_subtype type,
4789 struct sctp_cmd_seq *commands)
4791 struct sctp_association *my_asoc;
4792 struct sctp_chunk *repl;
4794 /* The comment below says that we enter COOKIE-WAIT AFTER
4795 * sending the INIT, but that doesn't actually work in our
4798 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4799 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4801 /* RFC 2960 5.1 Normal Establishment of an Association
4803 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4804 * must provide its Verification Tag (Tag_A) in the Initiate
4805 * Tag field. Tag_A SHOULD be a random number in the range of
4806 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4809 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4813 /* Choose transport for INIT. */
4814 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4817 /* Cast away the const modifier, as we want to just
4818 * rerun it through as a sideffect.
4820 my_asoc = (struct sctp_association *)asoc;
4821 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4823 /* After sending the INIT, "A" starts the T1-init timer and
4824 * enters the COOKIE-WAIT state.
4826 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4827 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4828 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4829 return SCTP_DISPOSITION_CONSUME;
4832 return SCTP_DISPOSITION_NOMEM;
4836 * Process the SEND primitive.
4838 * Section: 10.1 ULP-to-SCTP
4841 * Format: SEND(association id, buffer address, byte count [,context]
4842 * [,stream id] [,life time] [,destination transport address]
4843 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4846 * This is the main method to send user data via SCTP.
4848 * Mandatory attributes:
4850 * o association id - local handle to the SCTP association
4852 * o buffer address - the location where the user message to be
4853 * transmitted is stored;
4855 * o byte count - The size of the user data in number of bytes;
4857 * Optional attributes:
4859 * o context - an optional 32 bit integer that will be carried in the
4860 * sending failure notification to the ULP if the transportation of
4861 * this User Message fails.
4863 * o stream id - to indicate which stream to send the data on. If not
4864 * specified, stream 0 will be used.
4866 * o life time - specifies the life time of the user data. The user data
4867 * will not be sent by SCTP after the life time expires. This
4868 * parameter can be used to avoid efforts to transmit stale
4869 * user messages. SCTP notifies the ULP if the data cannot be
4870 * initiated to transport (i.e. sent to the destination via SCTP's
4871 * send primitive) within the life time variable. However, the
4872 * user data will be transmitted if SCTP has attempted to transmit a
4873 * chunk before the life time expired.
4875 * o destination transport address - specified as one of the destination
4876 * transport addresses of the peer endpoint to which this packet
4877 * should be sent. Whenever possible, SCTP should use this destination
4878 * transport address for sending the packets, instead of the current
4881 * o unorder flag - this flag, if present, indicates that the user
4882 * would like the data delivered in an unordered fashion to the peer
4883 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4886 * o no-bundle flag - instructs SCTP not to bundle this user data with
4887 * other outbound DATA chunks. SCTP MAY still bundle even when
4888 * this flag is present, when faced with network congestion.
4890 * o payload protocol-id - A 32 bit unsigned integer that is to be
4891 * passed to the peer indicating the type of payload protocol data
4892 * being transmitted. This value is passed as opaque data by SCTP.
4894 * The return value is the disposition.
4896 enum sctp_disposition sctp_sf_do_prm_send(struct net *net,
4897 const struct sctp_endpoint *ep,
4898 const struct sctp_association *asoc,
4899 const union sctp_subtype type,
4901 struct sctp_cmd_seq *commands)
4903 struct sctp_datamsg *msg = arg;
4905 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4906 return SCTP_DISPOSITION_CONSUME;
4910 * Process the SHUTDOWN primitive.
4915 * Format: SHUTDOWN(association id)
4918 * Gracefully closes an association. Any locally queued user data
4919 * will be delivered to the peer. The association will be terminated only
4920 * after the peer acknowledges all the SCTP packets sent. A success code
4921 * will be returned on successful termination of the association. If
4922 * attempting to terminate the association results in a failure, an error
4923 * code shall be returned.
4925 * Mandatory attributes:
4927 * o association id - local handle to the SCTP association
4929 * Optional attributes:
4933 * The return value is the disposition.
4935 enum sctp_disposition sctp_sf_do_9_2_prm_shutdown(
4937 const struct sctp_endpoint *ep,
4938 const struct sctp_association *asoc,
4939 const union sctp_subtype type,
4941 struct sctp_cmd_seq *commands)
4943 enum sctp_disposition disposition;
4945 /* From 9.2 Shutdown of an Association
4946 * Upon receipt of the SHUTDOWN primitive from its upper
4947 * layer, the endpoint enters SHUTDOWN-PENDING state and
4948 * remains there until all outstanding data has been
4949 * acknowledged by its peer. The endpoint accepts no new data
4950 * from its upper layer, but retransmits data to the far end
4951 * if necessary to fill gaps.
4953 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4954 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4956 disposition = SCTP_DISPOSITION_CONSUME;
4957 if (sctp_outq_is_empty(&asoc->outqueue)) {
4958 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
4966 * Process the ABORT primitive.
4971 * Format: Abort(association id [, cause code])
4974 * Ungracefully closes an association. Any locally queued user data
4975 * will be discarded and an ABORT chunk is sent to the peer. A success code
4976 * will be returned on successful abortion of the association. If
4977 * attempting to abort the association results in a failure, an error
4978 * code shall be returned.
4980 * Mandatory attributes:
4982 * o association id - local handle to the SCTP association
4984 * Optional attributes:
4986 * o cause code - reason of the abort to be passed to the peer
4990 * The return value is the disposition.
4992 enum sctp_disposition sctp_sf_do_9_1_prm_abort(
4994 const struct sctp_endpoint *ep,
4995 const struct sctp_association *asoc,
4996 const union sctp_subtype type,
4998 struct sctp_cmd_seq *commands)
5000 /* From 9.1 Abort of an Association
5001 * Upon receipt of the ABORT primitive from its upper
5002 * layer, the endpoint enters CLOSED state and
5003 * discard all outstanding data has been
5004 * acknowledged by its peer. The endpoint accepts no new data
5005 * from its upper layer, but retransmits data to the far end
5006 * if necessary to fill gaps.
5008 struct sctp_chunk *abort = arg;
5011 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
5013 /* Even if we can't send the ABORT due to low memory delete the
5014 * TCB. This is a departure from our typical NOMEM handling.
5017 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5018 SCTP_ERROR(ECONNABORTED));
5019 /* Delete the established association. */
5020 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5021 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5023 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5024 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5026 return SCTP_DISPOSITION_ABORT;
5029 /* We tried an illegal operation on an association which is closed. */
5030 enum sctp_disposition sctp_sf_error_closed(struct net *net,
5031 const struct sctp_endpoint *ep,
5032 const struct sctp_association *asoc,
5033 const union sctp_subtype type,
5035 struct sctp_cmd_seq *commands)
5037 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
5038 return SCTP_DISPOSITION_CONSUME;
5041 /* We tried an illegal operation on an association which is shutting
5044 enum sctp_disposition sctp_sf_error_shutdown(
5046 const struct sctp_endpoint *ep,
5047 const struct sctp_association *asoc,
5048 const union sctp_subtype type,
5050 struct sctp_cmd_seq *commands)
5052 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
5053 SCTP_ERROR(-ESHUTDOWN));
5054 return SCTP_DISPOSITION_CONSUME;
5058 * sctp_cookie_wait_prm_shutdown
5060 * Section: 4 Note: 2
5065 * The RFC does not explicitly address this issue, but is the route through the
5066 * state table when someone issues a shutdown while in COOKIE_WAIT state.
5071 enum sctp_disposition sctp_sf_cookie_wait_prm_shutdown(
5073 const struct sctp_endpoint *ep,
5074 const struct sctp_association *asoc,
5075 const union sctp_subtype type,
5077 struct sctp_cmd_seq *commands)
5079 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5080 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5082 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5083 SCTP_STATE(SCTP_STATE_CLOSED));
5085 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
5087 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
5089 return SCTP_DISPOSITION_DELETE_TCB;
5093 * sctp_cookie_echoed_prm_shutdown
5095 * Section: 4 Note: 2
5100 * The RFC does not explcitly address this issue, but is the route through the
5101 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
5106 enum sctp_disposition sctp_sf_cookie_echoed_prm_shutdown(
5108 const struct sctp_endpoint *ep,
5109 const struct sctp_association *asoc,
5110 const union sctp_subtype type,
5112 struct sctp_cmd_seq *commands)
5114 /* There is a single T1 timer, so we should be able to use
5115 * common function with the COOKIE-WAIT state.
5117 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
5121 * sctp_sf_cookie_wait_prm_abort
5123 * Section: 4 Note: 2
5128 * The RFC does not explicitly address this issue, but is the route through the
5129 * state table when someone issues an abort while in COOKIE_WAIT state.
5134 enum sctp_disposition sctp_sf_cookie_wait_prm_abort(
5136 const struct sctp_endpoint *ep,
5137 const struct sctp_association *asoc,
5138 const union sctp_subtype type,
5140 struct sctp_cmd_seq *commands)
5142 struct sctp_chunk *abort = arg;
5144 /* Stop T1-init timer */
5145 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5146 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5149 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
5151 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5152 SCTP_STATE(SCTP_STATE_CLOSED));
5154 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5156 /* Even if we can't send the ABORT due to low memory delete the
5157 * TCB. This is a departure from our typical NOMEM handling.
5160 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5161 SCTP_ERROR(ECONNREFUSED));
5162 /* Delete the established association. */
5163 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5164 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5166 return SCTP_DISPOSITION_ABORT;
5170 * sctp_sf_cookie_echoed_prm_abort
5172 * Section: 4 Note: 3
5177 * The RFC does not explcitly address this issue, but is the route through the
5178 * state table when someone issues an abort while in COOKIE_ECHOED state.
5183 enum sctp_disposition sctp_sf_cookie_echoed_prm_abort(
5185 const struct sctp_endpoint *ep,
5186 const struct sctp_association *asoc,
5187 const union sctp_subtype type,
5189 struct sctp_cmd_seq *commands)
5191 /* There is a single T1 timer, so we should be able to use
5192 * common function with the COOKIE-WAIT state.
5194 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5198 * sctp_sf_shutdown_pending_prm_abort
5203 * The RFC does not explicitly address this issue, but is the route through the
5204 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5209 enum sctp_disposition sctp_sf_shutdown_pending_prm_abort(
5211 const struct sctp_endpoint *ep,
5212 const struct sctp_association *asoc,
5213 const union sctp_subtype type,
5215 struct sctp_cmd_seq *commands)
5217 /* Stop the T5-shutdown guard timer. */
5218 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5219 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5221 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5225 * sctp_sf_shutdown_sent_prm_abort
5230 * The RFC does not explicitly address this issue, but is the route through the
5231 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5236 enum sctp_disposition sctp_sf_shutdown_sent_prm_abort(
5238 const struct sctp_endpoint *ep,
5239 const struct sctp_association *asoc,
5240 const union sctp_subtype type,
5242 struct sctp_cmd_seq *commands)
5244 /* Stop the T2-shutdown timer. */
5245 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5246 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5248 /* Stop the T5-shutdown guard timer. */
5249 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5250 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5252 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5256 * sctp_sf_cookie_echoed_prm_abort
5261 * The RFC does not explcitly address this issue, but is the route through the
5262 * state table when someone issues an abort while in COOKIE_ECHOED state.
5267 enum sctp_disposition sctp_sf_shutdown_ack_sent_prm_abort(
5269 const struct sctp_endpoint *ep,
5270 const struct sctp_association *asoc,
5271 const union sctp_subtype type,
5273 struct sctp_cmd_seq *commands)
5275 /* The same T2 timer, so we should be able to use
5276 * common function with the SHUTDOWN-SENT state.
5278 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5282 * Process the REQUESTHEARTBEAT primitive
5285 * J) Request Heartbeat
5287 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5291 * Instructs the local endpoint to perform a HeartBeat on the specified
5292 * destination transport address of the given association. The returned
5293 * result should indicate whether the transmission of the HEARTBEAT
5294 * chunk to the destination address is successful.
5296 * Mandatory attributes:
5298 * o association id - local handle to the SCTP association
5300 * o destination transport address - the transport address of the
5301 * association on which a heartbeat should be issued.
5303 enum sctp_disposition sctp_sf_do_prm_requestheartbeat(
5305 const struct sctp_endpoint *ep,
5306 const struct sctp_association *asoc,
5307 const union sctp_subtype type,
5309 struct sctp_cmd_seq *commands)
5311 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5312 (struct sctp_transport *)arg, commands))
5313 return SCTP_DISPOSITION_NOMEM;
5316 * RFC 2960 (bis), section 8.3
5318 * D) Request an on-demand HEARTBEAT on a specific destination
5319 * transport address of a given association.
5321 * The endpoint should increment the respective error counter of
5322 * the destination transport address each time a HEARTBEAT is sent
5323 * to that address and not acknowledged within one RTO.
5326 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5327 SCTP_TRANSPORT(arg));
5328 return SCTP_DISPOSITION_CONSUME;
5332 * ADDIP Section 4.1 ASCONF Chunk Procedures
5333 * When an endpoint has an ASCONF signaled change to be sent to the
5334 * remote endpoint it should do A1 to A9
5336 enum sctp_disposition sctp_sf_do_prm_asconf(struct net *net,
5337 const struct sctp_endpoint *ep,
5338 const struct sctp_association *asoc,
5339 const union sctp_subtype type,
5341 struct sctp_cmd_seq *commands)
5343 struct sctp_chunk *chunk = arg;
5345 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5347 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5348 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5349 return SCTP_DISPOSITION_CONSUME;
5352 /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5353 enum sctp_disposition sctp_sf_do_prm_reconf(struct net *net,
5354 const struct sctp_endpoint *ep,
5355 const struct sctp_association *asoc,
5356 const union sctp_subtype type,
5358 struct sctp_cmd_seq *commands)
5360 struct sctp_chunk *chunk = arg;
5362 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5363 return SCTP_DISPOSITION_CONSUME;
5367 * Ignore the primitive event
5369 * The return value is the disposition of the primitive.
5371 enum sctp_disposition sctp_sf_ignore_primitive(
5373 const struct sctp_endpoint *ep,
5374 const struct sctp_association *asoc,
5375 const union sctp_subtype type,
5377 struct sctp_cmd_seq *commands)
5379 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5382 return SCTP_DISPOSITION_DISCARD;
5385 /***************************************************************************
5386 * These are the state functions for the OTHER events.
5387 ***************************************************************************/
5390 * When the SCTP stack has no more user data to send or retransmit, this
5391 * notification is given to the user. Also, at the time when a user app
5392 * subscribes to this event, if there is no data to be sent or
5393 * retransmit, the stack will immediately send up this notification.
5395 enum sctp_disposition sctp_sf_do_no_pending_tsn(
5397 const struct sctp_endpoint *ep,
5398 const struct sctp_association *asoc,
5399 const union sctp_subtype type,
5401 struct sctp_cmd_seq *commands)
5403 struct sctp_ulpevent *event;
5405 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5407 return SCTP_DISPOSITION_NOMEM;
5409 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5411 return SCTP_DISPOSITION_CONSUME;
5415 * Start the shutdown negotiation.
5418 * Once all its outstanding data has been acknowledged, the endpoint
5419 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5420 * TSN Ack field the last sequential TSN it has received from the peer.
5421 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5422 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5423 * with the updated last sequential TSN received from its peer.
5425 * The return value is the disposition.
5427 enum sctp_disposition sctp_sf_do_9_2_start_shutdown(
5429 const struct sctp_endpoint *ep,
5430 const struct sctp_association *asoc,
5431 const union sctp_subtype type,
5433 struct sctp_cmd_seq *commands)
5435 struct sctp_chunk *reply;
5437 /* Once all its outstanding data has been acknowledged, the
5438 * endpoint shall send a SHUTDOWN chunk to its peer including
5439 * in the Cumulative TSN Ack field the last sequential TSN it
5440 * has received from the peer.
5442 reply = sctp_make_shutdown(asoc, NULL);
5446 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5447 * T2-shutdown timer.
5449 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5451 /* It shall then start the T2-shutdown timer */
5452 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5453 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5455 /* RFC 4960 Section 9.2
5456 * The sender of the SHUTDOWN MAY also start an overall guard timer
5457 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5459 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5460 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5462 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5463 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5464 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5466 /* and enter the SHUTDOWN-SENT state. */
5467 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5468 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5470 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5472 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5475 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5477 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5479 return SCTP_DISPOSITION_CONSUME;
5482 return SCTP_DISPOSITION_NOMEM;
5486 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5490 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5491 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5492 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5493 * endpoint must re-send the SHUTDOWN ACK.
5495 * The return value is the disposition.
5497 enum sctp_disposition sctp_sf_do_9_2_shutdown_ack(
5499 const struct sctp_endpoint *ep,
5500 const struct sctp_association *asoc,
5501 const union sctp_subtype type,
5503 struct sctp_cmd_seq *commands)
5505 struct sctp_chunk *chunk = arg;
5506 struct sctp_chunk *reply;
5508 /* There are 2 ways of getting here:
5509 * 1) called in response to a SHUTDOWN chunk
5510 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5512 * For the case (2), the arg parameter is set to NULL. We need
5513 * to check that we have a chunk before accessing it's fields.
5516 if (!sctp_vtag_verify(chunk, asoc))
5517 return sctp_sf_pdiscard(net, ep, asoc, type, arg,
5520 /* Make sure that the SHUTDOWN chunk has a valid length. */
5521 if (!sctp_chunk_length_valid(
5522 chunk, sizeof(struct sctp_shutdown_chunk)))
5523 return sctp_sf_violation_chunklen(net, ep, asoc, type,
5527 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5528 * shall send a SHUTDOWN ACK ...
5530 reply = sctp_make_shutdown_ack(asoc, chunk);
5534 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5535 * the T2-shutdown timer.
5537 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5539 /* and start/restart a T2-shutdown timer of its own, */
5540 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5541 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5543 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5544 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5545 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5547 /* Enter the SHUTDOWN-ACK-SENT state. */
5548 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5549 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5551 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5553 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5556 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5558 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5560 return SCTP_DISPOSITION_CONSUME;
5563 return SCTP_DISPOSITION_NOMEM;
5567 * Ignore the event defined as other
5569 * The return value is the disposition of the event.
5571 enum sctp_disposition sctp_sf_ignore_other(struct net *net,
5572 const struct sctp_endpoint *ep,
5573 const struct sctp_association *asoc,
5574 const union sctp_subtype type,
5576 struct sctp_cmd_seq *commands)
5578 pr_debug("%s: the event other type:%d is ignored\n",
5579 __func__, type.other);
5581 return SCTP_DISPOSITION_DISCARD;
5584 /************************************************************
5585 * These are the state functions for handling timeout events.
5586 ************************************************************/
5591 * Section: 6.3.3 Handle T3-rtx Expiration
5593 * Whenever the retransmission timer T3-rtx expires for a destination
5594 * address, do the following:
5597 * The return value is the disposition of the chunk.
5599 enum sctp_disposition sctp_sf_do_6_3_3_rtx(struct net *net,
5600 const struct sctp_endpoint *ep,
5601 const struct sctp_association *asoc,
5602 const union sctp_subtype type,
5604 struct sctp_cmd_seq *commands)
5606 struct sctp_transport *transport = arg;
5608 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5610 if (asoc->overall_error_count >= asoc->max_retrans) {
5611 if (asoc->peer.zero_window_announced &&
5612 asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5614 * We are here likely because the receiver had its rwnd
5615 * closed for a while and we have not been able to
5616 * transmit the locally queued data within the maximum
5617 * retransmission attempts limit. Start the T5
5618 * shutdown guard timer to give the receiver one last
5619 * chance and some additional time to recover before
5622 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5623 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5625 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5626 SCTP_ERROR(ETIMEDOUT));
5627 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5628 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5629 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5630 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5631 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5632 return SCTP_DISPOSITION_DELETE_TCB;
5636 /* E1) For the destination address for which the timer
5637 * expires, adjust its ssthresh with rules defined in Section
5638 * 7.2.3 and set the cwnd <- MTU.
5641 /* E2) For the destination address for which the timer
5642 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5643 * maximum value discussed in rule C7 above (RTO.max) may be
5644 * used to provide an upper bound to this doubling operation.
5647 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5648 * outstanding DATA chunks for the address for which the
5649 * T3-rtx has expired will fit into a single packet, subject
5650 * to the MTU constraint for the path corresponding to the
5651 * destination transport address to which the retransmission
5652 * is being sent (this may be different from the address for
5653 * which the timer expires [see Section 6.4]). Call this
5654 * value K. Bundle and retransmit those K DATA chunks in a
5655 * single packet to the destination endpoint.
5657 * Note: Any DATA chunks that were sent to the address for
5658 * which the T3-rtx timer expired but did not fit in one MTU
5659 * (rule E3 above), should be marked for retransmission and
5660 * sent as soon as cwnd allows (normally when a SACK arrives).
5663 /* Do some failure management (Section 8.2). */
5664 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5666 /* NB: Rules E4 and F1 are implicit in R1. */
5667 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5669 return SCTP_DISPOSITION_CONSUME;
5673 * Generate delayed SACK on timeout
5675 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5677 * The guidelines on delayed acknowledgement algorithm specified in
5678 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5679 * acknowledgement SHOULD be generated for at least every second packet
5680 * (not every second DATA chunk) received, and SHOULD be generated
5681 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5682 * some situations it may be beneficial for an SCTP transmitter to be
5683 * more conservative than the algorithms detailed in this document
5684 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5685 * the following algorithms allow.
5687 enum sctp_disposition sctp_sf_do_6_2_sack(struct net *net,
5688 const struct sctp_endpoint *ep,
5689 const struct sctp_association *asoc,
5690 const union sctp_subtype type,
5692 struct sctp_cmd_seq *commands)
5694 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5695 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5696 return SCTP_DISPOSITION_CONSUME;
5700 * sctp_sf_t1_init_timer_expire
5702 * Section: 4 Note: 2
5707 * RFC 2960 Section 4 Notes
5708 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5709 * and re-start the T1-init timer without changing state. This MUST
5710 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5711 * endpoint MUST abort the initialization process and report the
5712 * error to SCTP user.
5718 enum sctp_disposition sctp_sf_t1_init_timer_expire(
5720 const struct sctp_endpoint *ep,
5721 const struct sctp_association *asoc,
5722 const union sctp_subtype type,
5724 struct sctp_cmd_seq *commands)
5726 int attempts = asoc->init_err_counter + 1;
5727 struct sctp_chunk *repl = NULL;
5728 struct sctp_bind_addr *bp;
5730 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5732 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5734 if (attempts <= asoc->max_init_attempts) {
5735 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5736 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5738 return SCTP_DISPOSITION_NOMEM;
5740 /* Choose transport for INIT. */
5741 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5744 /* Issue a sideeffect to do the needed accounting. */
5745 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5746 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5748 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5750 pr_debug("%s: giving up on INIT, attempts:%d "
5751 "max_init_attempts:%d\n", __func__, attempts,
5752 asoc->max_init_attempts);
5754 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5755 SCTP_ERROR(ETIMEDOUT));
5756 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5757 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5758 return SCTP_DISPOSITION_DELETE_TCB;
5761 return SCTP_DISPOSITION_CONSUME;
5765 * sctp_sf_t1_cookie_timer_expire
5767 * Section: 4 Note: 2
5772 * RFC 2960 Section 4 Notes
5773 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5774 * COOKIE ECHO and re-start the T1-cookie timer without changing
5775 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5776 * After that, the endpoint MUST abort the initialization process and
5777 * report the error to SCTP user.
5783 enum sctp_disposition sctp_sf_t1_cookie_timer_expire(
5785 const struct sctp_endpoint *ep,
5786 const struct sctp_association *asoc,
5787 const union sctp_subtype type,
5789 struct sctp_cmd_seq *commands)
5791 int attempts = asoc->init_err_counter + 1;
5792 struct sctp_chunk *repl = NULL;
5794 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5796 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5798 if (attempts <= asoc->max_init_attempts) {
5799 repl = sctp_make_cookie_echo(asoc, NULL);
5801 return SCTP_DISPOSITION_NOMEM;
5803 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5805 /* Issue a sideeffect to do the needed accounting. */
5806 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5807 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5809 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5811 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5812 SCTP_ERROR(ETIMEDOUT));
5813 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5814 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5815 return SCTP_DISPOSITION_DELETE_TCB;
5818 return SCTP_DISPOSITION_CONSUME;
5821 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5822 * with the updated last sequential TSN received from its peer.
5824 * An endpoint should limit the number of retransmissions of the
5825 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5826 * If this threshold is exceeded the endpoint should destroy the TCB and
5827 * MUST report the peer endpoint unreachable to the upper layer (and
5828 * thus the association enters the CLOSED state). The reception of any
5829 * packet from its peer (i.e. as the peer sends all of its queued DATA
5830 * chunks) should clear the endpoint's retransmission count and restart
5831 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5832 * all of its queued DATA chunks that have not yet been sent.
5834 enum sctp_disposition sctp_sf_t2_timer_expire(
5836 const struct sctp_endpoint *ep,
5837 const struct sctp_association *asoc,
5838 const union sctp_subtype type,
5840 struct sctp_cmd_seq *commands)
5842 struct sctp_chunk *reply = NULL;
5844 pr_debug("%s: timer T2 expired\n", __func__);
5846 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5848 ((struct sctp_association *)asoc)->shutdown_retries++;
5850 if (asoc->overall_error_count >= asoc->max_retrans) {
5851 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5852 SCTP_ERROR(ETIMEDOUT));
5853 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5854 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5855 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5856 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5857 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5858 return SCTP_DISPOSITION_DELETE_TCB;
5861 switch (asoc->state) {
5862 case SCTP_STATE_SHUTDOWN_SENT:
5863 reply = sctp_make_shutdown(asoc, NULL);
5866 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5867 reply = sctp_make_shutdown_ack(asoc, NULL);
5878 /* Do some failure management (Section 8.2).
5879 * If we remove the transport an SHUTDOWN was last sent to, don't
5880 * do failure management.
5882 if (asoc->shutdown_last_sent_to)
5883 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5884 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5886 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5887 * the T2-shutdown timer.
5889 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5891 /* Restart the T2-shutdown timer. */
5892 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5893 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5894 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5895 return SCTP_DISPOSITION_CONSUME;
5898 return SCTP_DISPOSITION_NOMEM;
5902 * ADDIP Section 4.1 ASCONF CHunk Procedures
5903 * If the T4 RTO timer expires the endpoint should do B1 to B5
5905 enum sctp_disposition sctp_sf_t4_timer_expire(
5907 const struct sctp_endpoint *ep,
5908 const struct sctp_association *asoc,
5909 const union sctp_subtype type,
5911 struct sctp_cmd_seq *commands)
5913 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5914 struct sctp_transport *transport = chunk->transport;
5916 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
5918 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5919 * detection on the appropriate destination address as defined in
5920 * RFC2960 [5] section 8.1 and 8.2.
5923 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5924 SCTP_TRANSPORT(transport));
5926 /* Reconfig T4 timer and transport. */
5927 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5929 /* ADDIP 4.1 B2) Increment the association error counters and perform
5930 * endpoint failure detection on the association as defined in
5931 * RFC2960 [5] section 8.1 and 8.2.
5932 * association error counter is incremented in SCTP_CMD_STRIKE.
5934 if (asoc->overall_error_count >= asoc->max_retrans) {
5935 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5936 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5937 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5938 SCTP_ERROR(ETIMEDOUT));
5939 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5940 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5941 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5942 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5943 return SCTP_DISPOSITION_ABORT;
5946 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5947 * the ASCONF chunk was sent by doubling the RTO timer value.
5948 * This is done in SCTP_CMD_STRIKE.
5951 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5952 * choose an alternate destination address (please refer to RFC2960
5953 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5954 * chunk, it MUST be the same (including its serial number) as the last
5957 sctp_chunk_hold(asoc->addip_last_asconf);
5958 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5959 SCTP_CHUNK(asoc->addip_last_asconf));
5961 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5962 * destination is selected, then the RTO used will be that of the new
5963 * destination address.
5965 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5966 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5968 return SCTP_DISPOSITION_CONSUME;
5971 /* sctpimpguide-05 Section 2.12.2
5972 * The sender of the SHUTDOWN MAY also start an overall guard timer
5973 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5974 * At the expiration of this timer the sender SHOULD abort the association
5975 * by sending an ABORT chunk.
5977 enum sctp_disposition sctp_sf_t5_timer_expire(
5979 const struct sctp_endpoint *ep,
5980 const struct sctp_association *asoc,
5981 const union sctp_subtype type,
5983 struct sctp_cmd_seq *commands)
5985 struct sctp_chunk *reply = NULL;
5987 pr_debug("%s: timer T5 expired\n", __func__);
5989 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5991 reply = sctp_make_abort(asoc, NULL, 0);
5995 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5996 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5997 SCTP_ERROR(ETIMEDOUT));
5998 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5999 SCTP_PERR(SCTP_ERROR_NO_ERROR));
6001 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6002 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6004 return SCTP_DISPOSITION_DELETE_TCB;
6006 return SCTP_DISPOSITION_NOMEM;
6009 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
6010 * the association is automatically closed by starting the shutdown process.
6011 * The work that needs to be done is same as when SHUTDOWN is initiated by
6012 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
6014 enum sctp_disposition sctp_sf_autoclose_timer_expire(
6016 const struct sctp_endpoint *ep,
6017 const struct sctp_association *asoc,
6018 const union sctp_subtype type,
6020 struct sctp_cmd_seq *commands)
6022 enum sctp_disposition disposition;
6024 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
6026 /* From 9.2 Shutdown of an Association
6027 * Upon receipt of the SHUTDOWN primitive from its upper
6028 * layer, the endpoint enters SHUTDOWN-PENDING state and
6029 * remains there until all outstanding data has been
6030 * acknowledged by its peer. The endpoint accepts no new data
6031 * from its upper layer, but retransmits data to the far end
6032 * if necessary to fill gaps.
6034 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
6035 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
6037 disposition = SCTP_DISPOSITION_CONSUME;
6038 if (sctp_outq_is_empty(&asoc->outqueue)) {
6039 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
6046 /*****************************************************************************
6047 * These are sa state functions which could apply to all types of events.
6048 ****************************************************************************/
6051 * This table entry is not implemented.
6054 * (endpoint, asoc, chunk)
6056 * The return value is the disposition of the chunk.
6058 enum sctp_disposition sctp_sf_not_impl(struct net *net,
6059 const struct sctp_endpoint *ep,
6060 const struct sctp_association *asoc,
6061 const union sctp_subtype type,
6062 void *arg, struct sctp_cmd_seq *commands)
6064 return SCTP_DISPOSITION_NOT_IMPL;
6068 * This table entry represents a bug.
6071 * (endpoint, asoc, chunk)
6073 * The return value is the disposition of the chunk.
6075 enum sctp_disposition sctp_sf_bug(struct net *net,
6076 const struct sctp_endpoint *ep,
6077 const struct sctp_association *asoc,
6078 const union sctp_subtype type,
6079 void *arg, struct sctp_cmd_seq *commands)
6081 return SCTP_DISPOSITION_BUG;
6085 * This table entry represents the firing of a timer in the wrong state.
6086 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
6087 * when the association is in the wrong state. This event should
6088 * be ignored, so as to prevent any rearming of the timer.
6091 * (endpoint, asoc, chunk)
6093 * The return value is the disposition of the chunk.
6095 enum sctp_disposition sctp_sf_timer_ignore(struct net *net,
6096 const struct sctp_endpoint *ep,
6097 const struct sctp_association *asoc,
6098 const union sctp_subtype type,
6100 struct sctp_cmd_seq *commands)
6102 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
6104 return SCTP_DISPOSITION_CONSUME;
6107 /********************************************************************
6108 * 2nd Level Abstractions
6109 ********************************************************************/
6111 /* Pull the SACK chunk based on the SACK header. */
6112 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
6114 struct sctp_sackhdr *sack;
6119 /* Protect ourselves from reading too far into
6120 * the skb from a bogus sender.
6122 sack = (struct sctp_sackhdr *) chunk->skb->data;
6124 num_blocks = ntohs(sack->num_gap_ack_blocks);
6125 num_dup_tsns = ntohs(sack->num_dup_tsns);
6126 len = sizeof(struct sctp_sackhdr);
6127 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
6128 if (len > chunk->skb->len)
6131 skb_pull(chunk->skb, len);
6136 /* Create an ABORT packet to be sent as a response, with the specified
6139 static struct sctp_packet *sctp_abort_pkt_new(
6141 const struct sctp_endpoint *ep,
6142 const struct sctp_association *asoc,
6143 struct sctp_chunk *chunk,
6144 const void *payload, size_t paylen)
6146 struct sctp_packet *packet;
6147 struct sctp_chunk *abort;
6149 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6153 * The T bit will be set if the asoc is NULL.
6155 abort = sctp_make_abort(asoc, chunk, paylen);
6157 sctp_ootb_pkt_free(packet);
6161 /* Reflect vtag if T-Bit is set */
6162 if (sctp_test_T_bit(abort))
6163 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
6165 /* Add specified error causes, i.e., payload, to the
6168 sctp_addto_chunk(abort, paylen, payload);
6170 /* Set the skb to the belonging sock for accounting. */
6171 abort->skb->sk = ep->base.sk;
6173 sctp_packet_append_chunk(packet, abort);
6180 /* Allocate a packet for responding in the OOTB conditions. */
6181 static struct sctp_packet *sctp_ootb_pkt_new(
6183 const struct sctp_association *asoc,
6184 const struct sctp_chunk *chunk)
6186 struct sctp_transport *transport;
6187 struct sctp_packet *packet;
6191 /* Get the source and destination port from the inbound packet. */
6192 sport = ntohs(chunk->sctp_hdr->dest);
6193 dport = ntohs(chunk->sctp_hdr->source);
6195 /* The V-tag is going to be the same as the inbound packet if no
6196 * association exists, otherwise, use the peer's vtag.
6199 /* Special case the INIT-ACK as there is no peer's vtag
6202 switch (chunk->chunk_hdr->type) {
6203 case SCTP_CID_INIT_ACK:
6205 struct sctp_initack_chunk *initack;
6207 initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
6208 vtag = ntohl(initack->init_hdr.init_tag);
6212 vtag = asoc->peer.i.init_tag;
6216 /* Special case the INIT and stale COOKIE_ECHO as there is no
6219 switch (chunk->chunk_hdr->type) {
6222 struct sctp_init_chunk *init;
6224 init = (struct sctp_init_chunk *)chunk->chunk_hdr;
6225 vtag = ntohl(init->init_hdr.init_tag);
6229 vtag = ntohl(chunk->sctp_hdr->vtag);
6234 /* Make a transport for the bucket, Eliza... */
6235 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6239 /* Cache a route for the transport with the chunk's destination as
6240 * the source address.
6242 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6243 sctp_sk(net->sctp.ctl_sock));
6245 packet = &transport->packet;
6246 sctp_packet_init(packet, transport, sport, dport);
6247 sctp_packet_config(packet, vtag, 0);
6255 /* Free the packet allocated earlier for responding in the OOTB condition. */
6256 void sctp_ootb_pkt_free(struct sctp_packet *packet)
6258 sctp_transport_free(packet->transport);
6261 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6262 static void sctp_send_stale_cookie_err(struct net *net,
6263 const struct sctp_endpoint *ep,
6264 const struct sctp_association *asoc,
6265 const struct sctp_chunk *chunk,
6266 struct sctp_cmd_seq *commands,
6267 struct sctp_chunk *err_chunk)
6269 struct sctp_packet *packet;
6272 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6274 struct sctp_signed_cookie *cookie;
6276 /* Override the OOTB vtag from the cookie. */
6277 cookie = chunk->subh.cookie_hdr;
6278 packet->vtag = cookie->c.peer_vtag;
6280 /* Set the skb to the belonging sock for accounting. */
6281 err_chunk->skb->sk = ep->base.sk;
6282 sctp_packet_append_chunk(packet, err_chunk);
6283 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6284 SCTP_PACKET(packet));
6285 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6287 sctp_chunk_free (err_chunk);
6292 /* Process a data chunk */
6293 static int sctp_eat_data(const struct sctp_association *asoc,
6294 struct sctp_chunk *chunk,
6295 struct sctp_cmd_seq *commands)
6297 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6298 struct sock *sk = asoc->base.sk;
6299 struct net *net = sock_net(sk);
6300 struct sctp_datahdr *data_hdr;
6301 struct sctp_chunk *err;
6302 enum sctp_verb deliver;
6307 data_hdr = (struct sctp_datahdr *)chunk->skb->data;
6308 chunk->subh.data_hdr = data_hdr;
6309 skb_pull(chunk->skb, sctp_datahdr_len(&asoc->stream));
6311 tsn = ntohl(data_hdr->tsn);
6312 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6314 /* ASSERT: Now skb->data is really the user data. */
6316 /* Process ECN based congestion.
6318 * Since the chunk structure is reused for all chunks within
6319 * a packet, we use ecn_ce_done to track if we've already
6320 * done CE processing for this packet.
6322 * We need to do ECN processing even if we plan to discard the
6326 if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) {
6327 struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af;
6328 chunk->ecn_ce_done = 1;
6330 if (af->is_ce(sctp_gso_headskb(chunk->skb))) {
6331 /* Do real work as sideffect. */
6332 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6337 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6339 /* The TSN is too high--silently discard the chunk and
6340 * count on it getting retransmitted later.
6343 chunk->asoc->stats.outofseqtsns++;
6344 return SCTP_IERROR_HIGH_TSN;
6345 } else if (tmp > 0) {
6346 /* This is a duplicate. Record it. */
6347 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6348 return SCTP_IERROR_DUP_TSN;
6351 /* This is a new TSN. */
6353 /* Discard if there is no room in the receive window.
6354 * Actually, allow a little bit of overflow (up to a MTU).
6356 datalen = ntohs(chunk->chunk_hdr->length);
6357 datalen -= sctp_datachk_len(&asoc->stream);
6359 deliver = SCTP_CMD_CHUNK_ULP;
6361 /* Think about partial delivery. */
6362 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6364 /* Even if we don't accept this chunk there is
6367 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6370 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6371 * seems a bit troublesome in that frag_point varies based on
6372 * PMTU. In cases, such as loopback, this might be a rather
6375 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6376 (datalen > asoc->rwnd + asoc->frag_point))) {
6378 /* If this is the next TSN, consider reneging to make
6379 * room. Note: Playing nice with a confused sender. A
6380 * malicious sender can still eat up all our buffer
6381 * space and in the future we may want to detect and
6382 * do more drastic reneging.
6384 if (sctp_tsnmap_has_gap(map) &&
6385 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6386 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6387 deliver = SCTP_CMD_RENEGE;
6389 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6390 __func__, tsn, datalen, asoc->rwnd);
6392 return SCTP_IERROR_IGNORE_TSN;
6397 * Also try to renege to limit our memory usage in the event that
6398 * we are under memory pressure
6399 * If we can't renege, don't worry about it, the sk_rmem_schedule
6400 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6401 * memory usage too much
6403 if (*sk->sk_prot_creator->memory_pressure) {
6404 if (sctp_tsnmap_has_gap(map) &&
6405 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6406 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6408 deliver = SCTP_CMD_RENEGE;
6413 * Section 3.3.10.9 No User Data (9)
6417 * No User Data: This error cause is returned to the originator of a
6418 * DATA chunk if a received DATA chunk has no user data.
6420 if (unlikely(0 == datalen)) {
6421 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6423 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6426 /* We are going to ABORT, so we might as well stop
6427 * processing the rest of the chunks in the packet.
6429 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6430 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6431 SCTP_ERROR(ECONNABORTED));
6432 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6433 SCTP_PERR(SCTP_ERROR_NO_DATA));
6434 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6435 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6436 return SCTP_IERROR_NO_DATA;
6439 chunk->data_accepted = 1;
6441 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6442 * if we renege and the chunk arrives again.
6444 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6445 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6447 chunk->asoc->stats.iuodchunks++;
6449 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6451 chunk->asoc->stats.iodchunks++;
6454 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6456 * If an endpoint receive a DATA chunk with an invalid stream
6457 * identifier, it shall acknowledge the reception of the DATA chunk
6458 * following the normal procedure, immediately send an ERROR chunk
6459 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6460 * and discard the DATA chunk.
6462 if (ntohs(data_hdr->stream) >= asoc->stream.incnt) {
6463 /* Mark tsn as received even though we drop it */
6464 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6466 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6468 sizeof(data_hdr->stream),
6471 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6473 return SCTP_IERROR_BAD_STREAM;
6476 /* Check to see if the SSN is possible for this TSN.
6477 * The biggest gap we can record is 4K wide. Since SSNs wrap
6478 * at an unsigned short, there is no way that an SSN can
6479 * wrap and for a valid TSN. We can simply check if the current
6480 * SSN is smaller then the next expected one. If it is, it wrapped
6483 if (!asoc->stream.si->validate_data(chunk))
6484 return SCTP_IERROR_PROTO_VIOLATION;
6486 /* Send the data up to the user. Note: Schedule the
6487 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6488 * chunk needs the updated rwnd.
6490 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6492 return SCTP_IERROR_NO_ERROR;