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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
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 Intel Corp. | |
6 | * | |
60c778b2 | 7 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
8 | * |
9 | * These are definitions needed by the state machine. | |
10 | * | |
60c778b2 | 11 | * This SCTP implementation is free software; |
1da177e4 LT |
12 | * 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 | * | |
60c778b2 | 17 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
18 | * 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 | |
24 | * along with GNU CC; see the file COPYING. If not, write to | |
25 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
26 | * Boston, MA 02111-1307, USA. | |
27 | * | |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email addresses: | |
30 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
31 | * | |
32 | * Or submit a bug report through the following website: | |
33 | * http://www.sf.net/projects/lksctp | |
34 | * | |
35 | * Written or modified by: | |
36 | * La Monte H.P. Yarroll <piggy@acm.org> | |
37 | * Karl Knutson <karl@athena.chicago.il.us> | |
38 | * Xingang Guo <xingang.guo@intel.com> | |
39 | * Jon Grimm <jgrimm@us.ibm.com> | |
40 | * Dajiang Zhang <dajiang.zhang@nokia.com> | |
41 | * Sridhar Samudrala <sri@us.ibm.com> | |
42 | * Daisy Chang <daisyc@us.ibm.com> | |
43 | * Ardelle Fan <ardelle.fan@intel.com> | |
44 | * Kevin Gao <kevin.gao@intel.com> | |
45 | * | |
46 | * Any bugs reported given to us we will try to fix... any fixes shared will | |
47 | * be incorporated into the next SCTP release. | |
48 | */ | |
49 | ||
50 | #include <linux/types.h> | |
51 | #include <linux/compiler.h> | |
52 | #include <linux/slab.h> | |
53 | #include <linux/in.h> | |
54 | #include <net/sctp/command.h> | |
55 | #include <net/sctp/sctp.h> | |
56 | ||
57 | #ifndef __sctp_sm_h__ | |
58 | #define __sctp_sm_h__ | |
59 | ||
60 | /* | |
61 | * Possible values for the disposition are: | |
62 | */ | |
63 | typedef enum { | |
64 | SCTP_DISPOSITION_DISCARD, /* No further processing. */ | |
65 | SCTP_DISPOSITION_CONSUME, /* Process return values normally. */ | |
66 | SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */ | |
67 | SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */ | |
68 | SCTP_DISPOSITION_ABORT, /* Close the association NOW. */ | |
69 | SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */ | |
70 | SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */ | |
71 | SCTP_DISPOSITION_ERROR, /* This is plain old user error. */ | |
72 | SCTP_DISPOSITION_BUG, /* This is a bug. */ | |
73 | } sctp_disposition_t; | |
74 | ||
75 | typedef struct { | |
76 | int name; | |
77 | int action; | |
78 | } sctp_sm_command_t; | |
79 | ||
80 | typedef sctp_disposition_t (sctp_state_fn_t) (const struct sctp_endpoint *, | |
81 | const struct sctp_association *, | |
82 | const sctp_subtype_t type, | |
83 | void *arg, | |
84 | sctp_cmd_seq_t *); | |
85 | typedef void (sctp_timer_event_t) (unsigned long); | |
86 | typedef struct { | |
87 | sctp_state_fn_t *fn; | |
88 | const char *name; | |
89 | } sctp_sm_table_entry_t; | |
90 | ||
91 | /* A naming convention of "sctp_sf_xxx" applies to all the state functions | |
92 | * currently in use. | |
93 | */ | |
94 | ||
95 | /* Prototypes for generic state functions. */ | |
96 | sctp_state_fn_t sctp_sf_not_impl; | |
97 | sctp_state_fn_t sctp_sf_bug; | |
98 | ||
99 | /* Prototypes for gener timer state functions. */ | |
100 | sctp_state_fn_t sctp_sf_timer_ignore; | |
101 | ||
102 | /* Prototypes for chunk state functions. */ | |
103 | sctp_state_fn_t sctp_sf_do_9_1_abort; | |
104 | sctp_state_fn_t sctp_sf_cookie_wait_abort; | |
105 | sctp_state_fn_t sctp_sf_cookie_echoed_abort; | |
106 | sctp_state_fn_t sctp_sf_shutdown_pending_abort; | |
107 | sctp_state_fn_t sctp_sf_shutdown_sent_abort; | |
108 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; | |
109 | sctp_state_fn_t sctp_sf_do_5_1B_init; | |
110 | sctp_state_fn_t sctp_sf_do_5_1C_ack; | |
111 | sctp_state_fn_t sctp_sf_do_5_1D_ce; | |
112 | sctp_state_fn_t sctp_sf_do_5_1E_ca; | |
113 | sctp_state_fn_t sctp_sf_do_4_C; | |
114 | sctp_state_fn_t sctp_sf_eat_data_6_2; | |
115 | sctp_state_fn_t sctp_sf_eat_data_fast_4_4; | |
116 | sctp_state_fn_t sctp_sf_eat_sack_6_2; | |
1da177e4 | 117 | sctp_state_fn_t sctp_sf_operr_notify; |
3f7a87d2 FF |
118 | sctp_state_fn_t sctp_sf_t1_init_timer_expire; |
119 | sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; | |
1da177e4 LT |
120 | sctp_state_fn_t sctp_sf_t2_timer_expire; |
121 | sctp_state_fn_t sctp_sf_t4_timer_expire; | |
122 | sctp_state_fn_t sctp_sf_t5_timer_expire; | |
123 | sctp_state_fn_t sctp_sf_sendbeat_8_3; | |
124 | sctp_state_fn_t sctp_sf_beat_8_3; | |
125 | sctp_state_fn_t sctp_sf_backbeat_8_3; | |
126 | sctp_state_fn_t sctp_sf_do_9_2_final; | |
127 | sctp_state_fn_t sctp_sf_do_9_2_shutdown; | |
2e3f92da | 128 | sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; |
1da177e4 LT |
129 | sctp_state_fn_t sctp_sf_do_ecn_cwr; |
130 | sctp_state_fn_t sctp_sf_do_ecne; | |
131 | sctp_state_fn_t sctp_sf_ootb; | |
132 | sctp_state_fn_t sctp_sf_pdiscard; | |
133 | sctp_state_fn_t sctp_sf_violation; | |
1da177e4 LT |
134 | sctp_state_fn_t sctp_sf_discard_chunk; |
135 | sctp_state_fn_t sctp_sf_do_5_2_1_siminit; | |
136 | sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; | |
610ab73a | 137 | sctp_state_fn_t sctp_sf_do_5_2_3_initack; |
1da177e4 LT |
138 | sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; |
139 | sctp_state_fn_t sctp_sf_unk_chunk; | |
140 | sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; | |
141 | sctp_state_fn_t sctp_sf_cookie_echoed_err; | |
142 | sctp_state_fn_t sctp_sf_do_asconf; | |
143 | sctp_state_fn_t sctp_sf_do_asconf_ack; | |
144 | sctp_state_fn_t sctp_sf_do_9_2_reshutack; | |
145 | sctp_state_fn_t sctp_sf_eat_fwd_tsn; | |
146 | sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; | |
bbd0d598 | 147 | sctp_state_fn_t sctp_sf_eat_auth; |
1da177e4 LT |
148 | |
149 | /* Prototypes for primitive event state functions. */ | |
150 | sctp_state_fn_t sctp_sf_do_prm_asoc; | |
151 | sctp_state_fn_t sctp_sf_do_prm_send; | |
152 | sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; | |
153 | sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; | |
154 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; | |
155 | sctp_state_fn_t sctp_sf_do_9_1_prm_abort; | |
156 | sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; | |
157 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; | |
158 | sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; | |
159 | sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; | |
160 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; | |
161 | sctp_state_fn_t sctp_sf_error_closed; | |
162 | sctp_state_fn_t sctp_sf_error_shutdown; | |
163 | sctp_state_fn_t sctp_sf_ignore_primitive; | |
164 | sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; | |
165 | sctp_state_fn_t sctp_sf_do_prm_asconf; | |
166 | ||
167 | /* Prototypes for other event state functions. */ | |
e1cdd553 | 168 | sctp_state_fn_t sctp_sf_do_no_pending_tsn; |
1da177e4 LT |
169 | sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; |
170 | sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; | |
171 | sctp_state_fn_t sctp_sf_ignore_other; | |
172 | sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; | |
173 | ||
174 | /* Prototypes for timeout event state functions. */ | |
175 | sctp_state_fn_t sctp_sf_do_6_3_3_rtx; | |
176 | sctp_state_fn_t sctp_sf_do_6_2_sack; | |
177 | sctp_state_fn_t sctp_sf_autoclose_timer_expire; | |
178 | ||
179 | /* Prototypes for utility support functions. */ | |
180 | __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); | |
181 | const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t, | |
182 | sctp_state_t, | |
183 | sctp_subtype_t); | |
184 | int sctp_chunk_iif(const struct sctp_chunk *); | |
185 | struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, | |
186 | struct sctp_chunk *, | |
dd0fc66f | 187 | gfp_t gfp); |
1da177e4 LT |
188 | __u32 sctp_generate_verification_tag(void); |
189 | void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); | |
190 | ||
191 | /* Prototypes for chunk-building functions. */ | |
192 | struct sctp_chunk *sctp_make_init(const struct sctp_association *, | |
193 | const struct sctp_bind_addr *, | |
dd0fc66f | 194 | gfp_t gfp, int vparam_len); |
1da177e4 LT |
195 | struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, |
196 | const struct sctp_chunk *, | |
dd0fc66f | 197 | const gfp_t gfp, |
1da177e4 LT |
198 | const int unkparam_len); |
199 | struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, | |
200 | const struct sctp_chunk *); | |
201 | struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, | |
202 | const struct sctp_chunk *); | |
203 | struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, | |
204 | const __u32 lowest_tsn, | |
205 | const struct sctp_chunk *); | |
206 | struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, | |
207 | const struct sctp_sndrcvinfo *sinfo, | |
208 | int len, const __u8 flags, | |
209 | __u16 ssn); | |
210 | struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, | |
211 | const __u32); | |
212 | struct sctp_chunk *sctp_make_sack(const struct sctp_association *); | |
213 | struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, | |
214 | const struct sctp_chunk *chunk); | |
215 | struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, | |
216 | const struct sctp_chunk *); | |
217 | struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, | |
218 | const struct sctp_chunk *); | |
00f1c2df | 219 | void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); |
1da177e4 LT |
220 | struct sctp_chunk *sctp_make_abort(const struct sctp_association *, |
221 | const struct sctp_chunk *, | |
222 | const size_t hint); | |
223 | struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, | |
224 | const struct sctp_chunk *, | |
225 | __u32 tsn); | |
226 | struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, | |
c164a9ba | 227 | const struct msghdr *, size_t msg_len); |
1da177e4 LT |
228 | struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, |
229 | const struct sctp_chunk *, | |
230 | const __u8 *, | |
231 | const size_t ); | |
ba016670 WY |
232 | struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, |
233 | const struct sctp_chunk *, | |
234 | struct sctp_paramhdr *); | |
1da177e4 | 235 | struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, |
92c73af5 | 236 | const struct sctp_transport *); |
1da177e4 LT |
237 | struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, |
238 | const struct sctp_chunk *, | |
239 | const void *payload, | |
240 | const size_t paylen); | |
241 | struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, | |
242 | const struct sctp_chunk *chunk, | |
63706c5c | 243 | __be16 cause_code, |
1da177e4 | 244 | const void *payload, |
6383cfb3 VY |
245 | size_t paylen, |
246 | size_t reserve_tail); | |
1da177e4 LT |
247 | |
248 | struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, | |
249 | union sctp_addr *, | |
250 | struct sockaddr *, | |
dbc16db1 | 251 | int, __be16); |
1da177e4 LT |
252 | struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, |
253 | union sctp_addr *addr); | |
6f4c618d WY |
254 | int sctp_verify_asconf(const struct sctp_association *asoc, |
255 | struct sctp_paramhdr *param_hdr, void *chunk_end, | |
256 | struct sctp_paramhdr **errp); | |
1da177e4 LT |
257 | struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, |
258 | struct sctp_chunk *asconf); | |
259 | int sctp_process_asconf_ack(struct sctp_association *asoc, | |
260 | struct sctp_chunk *asconf_ack); | |
261 | struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, | |
262 | __u32 new_cum_tsn, size_t nstreams, | |
263 | struct sctp_fwdtsn_skip *skiplist); | |
4cd57c80 | 264 | struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); |
1da177e4 LT |
265 | |
266 | void sctp_chunk_assign_tsn(struct sctp_chunk *); | |
267 | void sctp_chunk_assign_ssn(struct sctp_chunk *); | |
268 | ||
1da177e4 LT |
269 | /* Prototypes for statetable processing. */ |
270 | ||
271 | int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype, | |
272 | sctp_state_t state, | |
273 | struct sctp_endpoint *, | |
274 | struct sctp_association *asoc, | |
275 | void *event_arg, | |
dd0fc66f | 276 | gfp_t gfp); |
1da177e4 LT |
277 | |
278 | /* 2nd level prototypes */ | |
279 | void sctp_generate_t3_rtx_event(unsigned long peer); | |
280 | void sctp_generate_heartbeat_event(unsigned long peer); | |
50b5d6ad | 281 | void sctp_generate_proto_unreach_event(unsigned long peer); |
1da177e4 LT |
282 | |
283 | void sctp_ootb_pkt_free(struct sctp_packet *); | |
284 | ||
285 | struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, | |
286 | const struct sctp_association *, | |
3182cd84 | 287 | struct sctp_chunk *, |
dd0fc66f | 288 | gfp_t gfp, int *err, |
1da177e4 LT |
289 | struct sctp_chunk **err_chk_p); |
290 | int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, | |
291 | struct sockaddr_storage*, int); | |
292 | ||
293 | /* 3rd level prototypes */ | |
294 | __u32 sctp_generate_tag(const struct sctp_endpoint *); | |
295 | __u32 sctp_generate_tsn(const struct sctp_endpoint *); | |
296 | ||
297 | /* Extern declarations for major data structures. */ | |
298 | extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; | |
299 | ||
300 | ||
301 | /* Get the size of a DATA chunk payload. */ | |
302 | static inline __u16 sctp_data_size(struct sctp_chunk *chunk) | |
303 | { | |
304 | __u16 size; | |
305 | ||
306 | size = ntohs(chunk->chunk_hdr->length); | |
307 | size -= sizeof(sctp_data_chunk_t); | |
308 | ||
309 | return size; | |
310 | } | |
311 | ||
312 | /* Compare two TSNs */ | |
313 | ||
314 | /* RFC 1982 - Serial Number Arithmetic | |
315 | * | |
316 | * 2. Comparison | |
317 | * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, | |
318 | * in all other cases, s1 is not equal to s2. | |
319 | * | |
320 | * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, | |
321 | * and | |
322 | * | |
323 | * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or | |
324 | * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) | |
325 | * | |
326 | * s1 is said to be greater than s2 if, and only if, s1 is not equal to | |
327 | * s2, and | |
328 | * | |
329 | * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or | |
330 | * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) | |
331 | */ | |
332 | ||
333 | /* | |
334 | * RFC 2960 | |
335 | * 1.6 Serial Number Arithmetic | |
336 | * | |
337 | * Comparisons and arithmetic on TSNs in this document SHOULD use Serial | |
338 | * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. | |
339 | */ | |
340 | ||
341 | enum { | |
342 | TSN_SIGN_BIT = (1<<31) | |
343 | }; | |
344 | ||
345 | static inline int TSN_lt(__u32 s, __u32 t) | |
346 | { | |
a02cec21 | 347 | return ((s) - (t)) & TSN_SIGN_BIT; |
1da177e4 LT |
348 | } |
349 | ||
350 | static inline int TSN_lte(__u32 s, __u32 t) | |
351 | { | |
a02cec21 | 352 | return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); |
1da177e4 LT |
353 | } |
354 | ||
355 | /* Compare two SSNs */ | |
356 | ||
357 | /* | |
358 | * RFC 2960 | |
359 | * 1.6 Serial Number Arithmetic | |
360 | * | |
361 | * Comparisons and arithmetic on Stream Sequence Numbers in this document | |
362 | * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where | |
363 | * SERIAL_BITS = 16. | |
364 | */ | |
365 | enum { | |
366 | SSN_SIGN_BIT = (1<<15) | |
367 | }; | |
368 | ||
369 | static inline int SSN_lt(__u16 s, __u16 t) | |
370 | { | |
a02cec21 | 371 | return ((s) - (t)) & SSN_SIGN_BIT; |
1da177e4 LT |
372 | } |
373 | ||
374 | static inline int SSN_lte(__u16 s, __u16 t) | |
375 | { | |
a02cec21 | 376 | return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); |
1da177e4 LT |
377 | } |
378 | ||
379 | /* | |
380 | * ADDIP 3.1.1 | |
381 | * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial | |
382 | * Numbers wrap back to 0 after reaching 4294967295. | |
383 | */ | |
384 | enum { | |
385 | ADDIP_SERIAL_SIGN_BIT = (1<<31) | |
386 | }; | |
387 | ||
388 | static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) | |
389 | { | |
a02cec21 | 390 | return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); |
1da177e4 LT |
391 | } |
392 | ||
1da177e4 LT |
393 | /* Check VTAG of the packet matches the sender's own tag. */ |
394 | static inline int | |
395 | sctp_vtag_verify(const struct sctp_chunk *chunk, | |
396 | const struct sctp_association *asoc) | |
397 | { | |
398 | /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint | |
399 | * MUST ensure that the value in the Verification Tag field of | |
400 | * the received SCTP packet matches its own Tag. If the received | |
401 | * Verification Tag value does not match the receiver's own | |
402 | * tag value, the receiver shall silently discard the packet... | |
403 | */ | |
404 | if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) | |
405 | return 1; | |
406 | ||
407 | return 0; | |
408 | } | |
409 | ||
047a2428 JF |
410 | /* Check VTAG of the packet matches the sender's own tag and the T bit is |
411 | * not set, OR its peer's tag and the T bit is set in the Chunk Flags. | |
1da177e4 LT |
412 | */ |
413 | static inline int | |
414 | sctp_vtag_verify_either(const struct sctp_chunk *chunk, | |
415 | const struct sctp_association *asoc) | |
416 | { | |
047a2428 | 417 | /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 |
1da177e4 | 418 | * |
047a2428 JF |
419 | * B) The receiver of a ABORT MUST accept the packet |
420 | * if the Verification Tag field of the packet matches its own tag | |
421 | * and the T bit is not set | |
422 | * OR | |
423 | * it is set to its peer's tag and the T bit is set in the Chunk | |
424 | * Flags. | |
425 | * Otherwise, the receiver MUST silently discard the packet | |
426 | * and take no further action. | |
1da177e4 | 427 | * |
047a2428 JF |
428 | * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet |
429 | * if the Verification Tag field of the packet matches its own tag | |
430 | * and the T bit is not set | |
431 | * OR | |
432 | * it is set to its peer's tag and the T bit is set in the Chunk | |
433 | * Flags. | |
434 | * Otherwise, the receiver MUST silently discard the packet | |
435 | * and take no further action. An endpoint MUST ignore the | |
436 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. | |
1da177e4 | 437 | */ |
047a2428 JF |
438 | if ((!sctp_test_T_bit(chunk) && |
439 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || | |
52688d6e | 440 | (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && |
047a2428 | 441 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { |
1da177e4 LT |
442 | return 1; |
443 | } | |
444 | ||
445 | return 0; | |
446 | } | |
447 | ||
448 | #endif /* __sctp_sm_h__ */ |