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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05007 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * These are definitions needed by the state machine.
10 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050011 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050017 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080024 * along with GNU CC; see the file COPYING. If not, see
25 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 *
27 * Please send any bug reports or fixes you make to the
28 * email addresses:
Daniel Borkmann91705c62013-07-23 14:51:47 +020029 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Karl Knutson <karl@athena.chicago.il.us>
34 * Xingang Guo <xingang.guo@intel.com>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Dajiang Zhang <dajiang.zhang@nokia.com>
37 * Sridhar Samudrala <sri@us.ibm.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Ardelle Fan <ardelle.fan@intel.com>
40 * Kevin Gao <kevin.gao@intel.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 */
42
43#include <linux/types.h>
44#include <linux/compiler.h>
45#include <linux/slab.h>
46#include <linux/in.h>
47#include <net/sctp/command.h>
48#include <net/sctp/sctp.h>
49
50#ifndef __sctp_sm_h__
51#define __sctp_sm_h__
52
53/*
54 * Possible values for the disposition are:
55 */
56typedef enum {
57 SCTP_DISPOSITION_DISCARD, /* No further processing. */
58 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */
59 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */
60 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */
61 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */
62 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */
63 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */
64 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */
65 SCTP_DISPOSITION_BUG, /* This is a bug. */
66} sctp_disposition_t;
67
68typedef struct {
69 int name;
70 int action;
71} sctp_sm_command_t;
72
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000073typedef sctp_disposition_t (sctp_state_fn_t) (struct net *,
74 const struct sctp_endpoint *,
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 const struct sctp_association *,
76 const sctp_subtype_t type,
77 void *arg,
78 sctp_cmd_seq_t *);
79typedef void (sctp_timer_event_t) (unsigned long);
80typedef struct {
81 sctp_state_fn_t *fn;
82 const char *name;
83} sctp_sm_table_entry_t;
84
85/* A naming convention of "sctp_sf_xxx" applies to all the state functions
86 * currently in use.
87 */
88
89/* Prototypes for generic state functions. */
90sctp_state_fn_t sctp_sf_not_impl;
91sctp_state_fn_t sctp_sf_bug;
92
93/* Prototypes for gener timer state functions. */
94sctp_state_fn_t sctp_sf_timer_ignore;
95
96/* Prototypes for chunk state functions. */
97sctp_state_fn_t sctp_sf_do_9_1_abort;
98sctp_state_fn_t sctp_sf_cookie_wait_abort;
99sctp_state_fn_t sctp_sf_cookie_echoed_abort;
100sctp_state_fn_t sctp_sf_shutdown_pending_abort;
101sctp_state_fn_t sctp_sf_shutdown_sent_abort;
102sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
103sctp_state_fn_t sctp_sf_do_5_1B_init;
104sctp_state_fn_t sctp_sf_do_5_1C_ack;
105sctp_state_fn_t sctp_sf_do_5_1D_ce;
106sctp_state_fn_t sctp_sf_do_5_1E_ca;
107sctp_state_fn_t sctp_sf_do_4_C;
108sctp_state_fn_t sctp_sf_eat_data_6_2;
109sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
110sctp_state_fn_t sctp_sf_eat_sack_6_2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111sctp_state_fn_t sctp_sf_operr_notify;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700112sctp_state_fn_t sctp_sf_t1_init_timer_expire;
113sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114sctp_state_fn_t sctp_sf_t2_timer_expire;
115sctp_state_fn_t sctp_sf_t4_timer_expire;
116sctp_state_fn_t sctp_sf_t5_timer_expire;
117sctp_state_fn_t sctp_sf_sendbeat_8_3;
118sctp_state_fn_t sctp_sf_beat_8_3;
119sctp_state_fn_t sctp_sf_backbeat_8_3;
120sctp_state_fn_t sctp_sf_do_9_2_final;
121sctp_state_fn_t sctp_sf_do_9_2_shutdown;
Wei Yongjun2e3f92d2008-10-23 01:01:18 -0700122sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123sctp_state_fn_t sctp_sf_do_ecn_cwr;
124sctp_state_fn_t sctp_sf_do_ecne;
125sctp_state_fn_t sctp_sf_ootb;
126sctp_state_fn_t sctp_sf_pdiscard;
127sctp_state_fn_t sctp_sf_violation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128sctp_state_fn_t sctp_sf_discard_chunk;
129sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
130sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
Vlad Yasevich610ab732007-01-15 19:18:30 -0800131sctp_state_fn_t sctp_sf_do_5_2_3_initack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
133sctp_state_fn_t sctp_sf_unk_chunk;
134sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
135sctp_state_fn_t sctp_sf_cookie_echoed_err;
136sctp_state_fn_t sctp_sf_do_asconf;
137sctp_state_fn_t sctp_sf_do_asconf_ack;
138sctp_state_fn_t sctp_sf_do_9_2_reshutack;
139sctp_state_fn_t sctp_sf_eat_fwd_tsn;
140sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700141sctp_state_fn_t sctp_sf_eat_auth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143/* Prototypes for primitive event state functions. */
144sctp_state_fn_t sctp_sf_do_prm_asoc;
145sctp_state_fn_t sctp_sf_do_prm_send;
146sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
147sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
148sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
149sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
150sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
151sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
152sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
153sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
154sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
155sctp_state_fn_t sctp_sf_error_closed;
156sctp_state_fn_t sctp_sf_error_shutdown;
157sctp_state_fn_t sctp_sf_ignore_primitive;
158sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
159sctp_state_fn_t sctp_sf_do_prm_asconf;
160
161/* Prototypes for other event state functions. */
Wei Yongjune1cdd552011-04-17 17:29:03 +0000162sctp_state_fn_t sctp_sf_do_no_pending_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
164sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
165sctp_state_fn_t sctp_sf_ignore_other;
166sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
167
168/* Prototypes for timeout event state functions. */
169sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
170sctp_state_fn_t sctp_sf_do_6_2_sack;
171sctp_state_fn_t sctp_sf_autoclose_timer_expire;
172
173/* Prototypes for utility support functions. */
174__u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
Eric W. Biederman55e26eb2012-08-07 07:25:24 +0000175const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *,
176 sctp_event_t,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 sctp_state_t,
178 sctp_subtype_t);
179int sctp_chunk_iif(const struct sctp_chunk *);
180struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
181 struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100182 gfp_t gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183__u32 sctp_generate_verification_tag(void);
184void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
185
186/* Prototypes for chunk-building functions. */
187struct sctp_chunk *sctp_make_init(const struct sctp_association *,
188 const struct sctp_bind_addr *,
Al Virodd0fc662005-10-07 07:46:04 +0100189 gfp_t gfp, int vparam_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,
191 const struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100192 const gfp_t gfp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 const int unkparam_len);
194struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,
195 const struct sctp_chunk *);
196struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,
197 const struct sctp_chunk *);
198struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,
199 const __u32 lowest_tsn,
200 const struct sctp_chunk *);
201struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,
202 const struct sctp_sndrcvinfo *sinfo,
203 int len, const __u8 flags,
204 __u16 ssn);
205struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
206 const __u32);
207struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
208struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
209 const struct sctp_chunk *chunk);
210struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
211 const struct sctp_chunk *);
212struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
213 const struct sctp_chunk *);
Wei Yongjun00f1c2d2007-08-21 15:50:01 +0800214void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
216 const struct sctp_chunk *,
217 const size_t hint);
218struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,
219 const struct sctp_chunk *,
220 __u32 tsn);
221struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,
Al Viro6ce8e9c2014-04-06 21:25:44 -0400222 struct msghdr *, size_t msg_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
224 const struct sctp_chunk *,
225 const __u8 *,
226 const size_t );
Wei Yongjunba016672008-09-30 05:32:24 -0700227struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
228 const struct sctp_chunk *,
229 struct sctp_paramhdr *);
Neil Hormande4594a2012-11-20 10:14:30 +0000230struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *,
231 const struct sctp_chunk *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
Wei Yongjun92c73af2011-04-19 21:31:47 +0000233 const struct sctp_transport *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
235 const struct sctp_chunk *,
236 const void *payload,
237 const size_t paylen);
238struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,
239 const struct sctp_chunk *chunk,
Al Viro63706c52006-11-20 17:00:05 -0800240 __be16 cause_code,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 const void *payload,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -0500242 size_t paylen,
243 size_t reserve_tail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
245struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
246 union sctp_addr *,
247 struct sockaddr *,
Al Virodbc16db2006-11-20 17:01:42 -0800248 int, __be16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
250 union sctp_addr *addr);
Daniel Borkmann9de79222014-10-09 22:55:31 +0200251bool sctp_verify_asconf(const struct sctp_association *asoc,
252 struct sctp_chunk *chunk, bool addr_param_needed,
253 struct sctp_paramhdr **errp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
255 struct sctp_chunk *asconf);
256int sctp_process_asconf_ack(struct sctp_association *asoc,
257 struct sctp_chunk *asconf_ack);
258struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
259 __u32 new_cum_tsn, size_t nstreams,
260 struct sctp_fwdtsn_skip *skiplist);
Vlad Yasevich4cd57c82007-09-16 19:32:45 -0700261struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263void sctp_chunk_assign_tsn(struct sctp_chunk *);
264void sctp_chunk_assign_ssn(struct sctp_chunk *);
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266/* Prototypes for statetable processing. */
267
Eric W. Biederman55e26eb2012-08-07 07:25:24 +0000268int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 sctp_state_t state,
270 struct sctp_endpoint *,
271 struct sctp_association *asoc,
272 void *event_arg,
Al Virodd0fc662005-10-07 07:46:04 +0100273 gfp_t gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275/* 2nd level prototypes */
276void sctp_generate_t3_rtx_event(unsigned long peer);
277void sctp_generate_heartbeat_event(unsigned long peer);
Vlad Yasevich50b5d6a2010-05-06 00:56:07 -0700278void sctp_generate_proto_unreach_event(unsigned long peer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280void sctp_ootb_pkt_free(struct sctp_packet *);
281
282struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,
283 const struct sctp_association *,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -0700284 struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100285 gfp_t gfp, int *err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 struct sctp_chunk **err_chk_p);
287int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,
288 struct sockaddr_storage*, int);
289
290/* 3rd level prototypes */
291__u32 sctp_generate_tag(const struct sctp_endpoint *);
292__u32 sctp_generate_tsn(const struct sctp_endpoint *);
293
294/* Extern declarations for major data structures. */
295extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
296
297
298/* Get the size of a DATA chunk payload. */
299static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
300{
301 __u16 size;
302
303 size = ntohs(chunk->chunk_hdr->length);
304 size -= sizeof(sctp_data_chunk_t);
305
306 return size;
307}
308
309/* Compare two TSNs */
310
311/* RFC 1982 - Serial Number Arithmetic
312 *
313 * 2. Comparison
314 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,
315 * in all other cases, s1 is not equal to s2.
316 *
317 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,
318 * and
319 *
320 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or
321 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))
322 *
323 * s1 is said to be greater than s2 if, and only if, s1 is not equal to
324 * s2, and
325 *
326 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or
327 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))
328 */
329
330/*
331 * RFC 2960
332 * 1.6 Serial Number Arithmetic
333 *
334 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial
335 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.
336 */
337
338enum {
339 TSN_SIGN_BIT = (1<<31)
340};
341
342static inline int TSN_lt(__u32 s, __u32 t)
343{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000344 return ((s) - (t)) & TSN_SIGN_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345}
346
347static inline int TSN_lte(__u32 s, __u32 t)
348{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000349 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351
352/* Compare two SSNs */
353
354/*
355 * RFC 2960
356 * 1.6 Serial Number Arithmetic
357 *
358 * Comparisons and arithmetic on Stream Sequence Numbers in this document
359 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where
360 * SERIAL_BITS = 16.
361 */
362enum {
363 SSN_SIGN_BIT = (1<<15)
364};
365
366static inline int SSN_lt(__u16 s, __u16 t)
367{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000368 return ((s) - (t)) & SSN_SIGN_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369}
370
371static inline int SSN_lte(__u16 s, __u16 t)
372{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000373 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374}
375
376/*
377 * ADDIP 3.1.1
378 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial
379 * Numbers wrap back to 0 after reaching 4294967295.
380 */
381enum {
382 ADDIP_SERIAL_SIGN_BIT = (1<<31)
383};
384
385static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)
386{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000387 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388}
389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390/* Check VTAG of the packet matches the sender's own tag. */
391static inline int
392sctp_vtag_verify(const struct sctp_chunk *chunk,
393 const struct sctp_association *asoc)
394{
395 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
396 * MUST ensure that the value in the Verification Tag field of
397 * the received SCTP packet matches its own Tag. If the received
398 * Verification Tag value does not match the receiver's own
399 * tag value, the receiver shall silently discard the packet...
400 */
401 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
402 return 1;
403
404 return 0;
405}
406
Jerome Forissier047a2422005-04-28 11:58:43 -0700407/* Check VTAG of the packet matches the sender's own tag and the T bit is
408 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 */
410static inline int
411sctp_vtag_verify_either(const struct sctp_chunk *chunk,
412 const struct sctp_association *asoc)
413{
Jerome Forissier047a2422005-04-28 11:58:43 -0700414 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700416 * B) The receiver of a ABORT MUST accept the packet
417 * if the Verification Tag field of the packet matches its own tag
418 * and the T bit is not set
419 * OR
420 * it is set to its peer's tag and the T bit is set in the Chunk
421 * Flags.
422 * Otherwise, the receiver MUST silently discard the packet
423 * and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700425 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
426 * if the Verification Tag field of the packet matches its own tag
427 * and the T bit is not set
428 * OR
429 * it is set to its peer's tag and the T bit is set in the Chunk
430 * Flags.
431 * Otherwise, the receiver MUST silently discard the packet
432 * and take no further action. An endpoint MUST ignore the
433 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 */
Jerome Forissier047a2422005-04-28 11:58:43 -0700435 if ((!sctp_test_T_bit(chunk) &&
436 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
Wei Yongjun52688d62010-04-30 21:42:44 -0400437 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
Jerome Forissier047a2422005-04-28 11:58:43 -0700438 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 return 1;
440 }
441
442 return 0;
443}
444
445#endif /* __sctp_sm_h__ */