Commit | Line | Data |
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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 | |
4b2f13a2 JK |
24 | * along with GNU CC; see the file COPYING. If not, see |
25 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
26 | * |
27 | * Please send any bug reports or fixes you make to the | |
28 | * email addresses: | |
91705c61 | 29 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 30 | * |
1da177e4 LT |
31 | * 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> | |
1da177e4 LT |
41 | */ |
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 | */ | |
56 | typedef 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 | ||
68 | typedef struct { | |
69 | int name; | |
70 | int action; | |
71 | } sctp_sm_command_t; | |
72 | ||
24cb81a6 EB |
73 | typedef sctp_disposition_t (sctp_state_fn_t) (struct net *, |
74 | const struct sctp_endpoint *, | |
1da177e4 LT |
75 | const struct sctp_association *, |
76 | const sctp_subtype_t type, | |
77 | void *arg, | |
78 | sctp_cmd_seq_t *); | |
79 | typedef void (sctp_timer_event_t) (unsigned long); | |
80 | typedef 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. */ | |
90 | sctp_state_fn_t sctp_sf_not_impl; | |
91 | sctp_state_fn_t sctp_sf_bug; | |
92 | ||
93 | /* Prototypes for gener timer state functions. */ | |
94 | sctp_state_fn_t sctp_sf_timer_ignore; | |
95 | ||
96 | /* Prototypes for chunk state functions. */ | |
97 | sctp_state_fn_t sctp_sf_do_9_1_abort; | |
98 | sctp_state_fn_t sctp_sf_cookie_wait_abort; | |
99 | sctp_state_fn_t sctp_sf_cookie_echoed_abort; | |
100 | sctp_state_fn_t sctp_sf_shutdown_pending_abort; | |
101 | sctp_state_fn_t sctp_sf_shutdown_sent_abort; | |
102 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; | |
103 | sctp_state_fn_t sctp_sf_do_5_1B_init; | |
104 | sctp_state_fn_t sctp_sf_do_5_1C_ack; | |
105 | sctp_state_fn_t sctp_sf_do_5_1D_ce; | |
106 | sctp_state_fn_t sctp_sf_do_5_1E_ca; | |
107 | sctp_state_fn_t sctp_sf_do_4_C; | |
108 | sctp_state_fn_t sctp_sf_eat_data_6_2; | |
109 | sctp_state_fn_t sctp_sf_eat_data_fast_4_4; | |
110 | sctp_state_fn_t sctp_sf_eat_sack_6_2; | |
1da177e4 | 111 | sctp_state_fn_t sctp_sf_operr_notify; |
3f7a87d2 FF |
112 | sctp_state_fn_t sctp_sf_t1_init_timer_expire; |
113 | sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; | |
1da177e4 LT |
114 | sctp_state_fn_t sctp_sf_t2_timer_expire; |
115 | sctp_state_fn_t sctp_sf_t4_timer_expire; | |
116 | sctp_state_fn_t sctp_sf_t5_timer_expire; | |
117 | sctp_state_fn_t sctp_sf_sendbeat_8_3; | |
118 | sctp_state_fn_t sctp_sf_beat_8_3; | |
119 | sctp_state_fn_t sctp_sf_backbeat_8_3; | |
120 | sctp_state_fn_t sctp_sf_do_9_2_final; | |
121 | sctp_state_fn_t sctp_sf_do_9_2_shutdown; | |
2e3f92da | 122 | sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; |
1da177e4 LT |
123 | sctp_state_fn_t sctp_sf_do_ecn_cwr; |
124 | sctp_state_fn_t sctp_sf_do_ecne; | |
125 | sctp_state_fn_t sctp_sf_ootb; | |
126 | sctp_state_fn_t sctp_sf_pdiscard; | |
127 | sctp_state_fn_t sctp_sf_violation; | |
1da177e4 LT |
128 | sctp_state_fn_t sctp_sf_discard_chunk; |
129 | sctp_state_fn_t sctp_sf_do_5_2_1_siminit; | |
130 | sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; | |
610ab73a | 131 | sctp_state_fn_t sctp_sf_do_5_2_3_initack; |
1da177e4 LT |
132 | sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; |
133 | sctp_state_fn_t sctp_sf_unk_chunk; | |
134 | sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; | |
135 | sctp_state_fn_t sctp_sf_cookie_echoed_err; | |
136 | sctp_state_fn_t sctp_sf_do_asconf; | |
137 | sctp_state_fn_t sctp_sf_do_asconf_ack; | |
138 | sctp_state_fn_t sctp_sf_do_9_2_reshutack; | |
139 | sctp_state_fn_t sctp_sf_eat_fwd_tsn; | |
140 | sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; | |
bbd0d598 | 141 | sctp_state_fn_t sctp_sf_eat_auth; |
1da177e4 LT |
142 | |
143 | /* Prototypes for primitive event state functions. */ | |
144 | sctp_state_fn_t sctp_sf_do_prm_asoc; | |
145 | sctp_state_fn_t sctp_sf_do_prm_send; | |
146 | sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; | |
147 | sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; | |
148 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; | |
149 | sctp_state_fn_t sctp_sf_do_9_1_prm_abort; | |
150 | sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; | |
151 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; | |
152 | sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; | |
153 | sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; | |
154 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; | |
155 | sctp_state_fn_t sctp_sf_error_closed; | |
156 | sctp_state_fn_t sctp_sf_error_shutdown; | |
157 | sctp_state_fn_t sctp_sf_ignore_primitive; | |
158 | sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; | |
159 | sctp_state_fn_t sctp_sf_do_prm_asconf; | |
160 | ||
161 | /* Prototypes for other event state functions. */ | |
e1cdd553 | 162 | sctp_state_fn_t sctp_sf_do_no_pending_tsn; |
1da177e4 LT |
163 | sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; |
164 | sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; | |
165 | sctp_state_fn_t sctp_sf_ignore_other; | |
166 | sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; | |
167 | ||
168 | /* Prototypes for timeout event state functions. */ | |
169 | sctp_state_fn_t sctp_sf_do_6_3_3_rtx; | |
170 | sctp_state_fn_t sctp_sf_do_6_2_sack; | |
171 | sctp_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); | |
55e26eb9 EB |
175 | const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, |
176 | sctp_event_t, | |
1da177e4 LT |
177 | sctp_state_t, |
178 | sctp_subtype_t); | |
179 | int sctp_chunk_iif(const struct sctp_chunk *); | |
180 | struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, | |
181 | struct sctp_chunk *, | |
dd0fc66f | 182 | gfp_t gfp); |
1da177e4 LT |
183 | __u32 sctp_generate_verification_tag(void); |
184 | void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); | |
185 | ||
186 | /* Prototypes for chunk-building functions. */ | |
187 | struct sctp_chunk *sctp_make_init(const struct sctp_association *, | |
188 | const struct sctp_bind_addr *, | |
dd0fc66f | 189 | gfp_t gfp, int vparam_len); |
1da177e4 LT |
190 | struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, |
191 | const struct sctp_chunk *, | |
dd0fc66f | 192 | const gfp_t gfp, |
1da177e4 LT |
193 | const int unkparam_len); |
194 | struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, | |
195 | const struct sctp_chunk *); | |
196 | struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, | |
197 | const struct sctp_chunk *); | |
198 | struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, | |
199 | const __u32 lowest_tsn, | |
200 | const struct sctp_chunk *); | |
201 | struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, | |
202 | const struct sctp_sndrcvinfo *sinfo, | |
203 | int len, const __u8 flags, | |
204 | __u16 ssn); | |
205 | struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, | |
206 | const __u32); | |
207 | struct sctp_chunk *sctp_make_sack(const struct sctp_association *); | |
208 | struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, | |
209 | const struct sctp_chunk *chunk); | |
210 | struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, | |
211 | const struct sctp_chunk *); | |
212 | struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, | |
213 | const struct sctp_chunk *); | |
00f1c2df | 214 | void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); |
1da177e4 LT |
215 | struct sctp_chunk *sctp_make_abort(const struct sctp_association *, |
216 | const struct sctp_chunk *, | |
217 | const size_t hint); | |
218 | struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, | |
219 | const struct sctp_chunk *, | |
220 | __u32 tsn); | |
221 | struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, | |
6ce8e9ce | 222 | struct msghdr *, size_t msg_len); |
1da177e4 LT |
223 | struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, |
224 | const struct sctp_chunk *, | |
225 | const __u8 *, | |
226 | const size_t ); | |
ba016670 WY |
227 | struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, |
228 | const struct sctp_chunk *, | |
229 | struct sctp_paramhdr *); | |
de4594a5 NH |
230 | struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, |
231 | const struct sctp_chunk *); | |
1da177e4 | 232 | struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, |
92c73af5 | 233 | const struct sctp_transport *); |
1da177e4 LT |
234 | struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, |
235 | const struct sctp_chunk *, | |
236 | const void *payload, | |
237 | const size_t paylen); | |
238 | struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, | |
239 | const struct sctp_chunk *chunk, | |
63706c5c | 240 | __be16 cause_code, |
1da177e4 | 241 | const void *payload, |
6383cfb3 VY |
242 | size_t paylen, |
243 | size_t reserve_tail); | |
1da177e4 LT |
244 | |
245 | struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, | |
246 | union sctp_addr *, | |
247 | struct sockaddr *, | |
dbc16db1 | 248 | int, __be16); |
1da177e4 LT |
249 | struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, |
250 | union sctp_addr *addr); | |
9de7922b DB |
251 | bool sctp_verify_asconf(const struct sctp_association *asoc, |
252 | struct sctp_chunk *chunk, bool addr_param_needed, | |
253 | struct sctp_paramhdr **errp); | |
1da177e4 LT |
254 | struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, |
255 | struct sctp_chunk *asconf); | |
256 | int sctp_process_asconf_ack(struct sctp_association *asoc, | |
257 | struct sctp_chunk *asconf_ack); | |
258 | struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, | |
259 | __u32 new_cum_tsn, size_t nstreams, | |
260 | struct sctp_fwdtsn_skip *skiplist); | |
4cd57c80 | 261 | struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); |
1da177e4 LT |
262 | |
263 | void sctp_chunk_assign_tsn(struct sctp_chunk *); | |
264 | void sctp_chunk_assign_ssn(struct sctp_chunk *); | |
265 | ||
1da177e4 LT |
266 | /* Prototypes for statetable processing. */ |
267 | ||
55e26eb9 | 268 | int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, |
1da177e4 LT |
269 | sctp_state_t state, |
270 | struct sctp_endpoint *, | |
271 | struct sctp_association *asoc, | |
272 | void *event_arg, | |
dd0fc66f | 273 | gfp_t gfp); |
1da177e4 LT |
274 | |
275 | /* 2nd level prototypes */ | |
276 | void sctp_generate_t3_rtx_event(unsigned long peer); | |
277 | void sctp_generate_heartbeat_event(unsigned long peer); | |
50b5d6ad | 278 | void sctp_generate_proto_unreach_event(unsigned long peer); |
1da177e4 LT |
279 | |
280 | void sctp_ootb_pkt_free(struct sctp_packet *); | |
281 | ||
282 | struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, | |
283 | const struct sctp_association *, | |
3182cd84 | 284 | struct sctp_chunk *, |
dd0fc66f | 285 | gfp_t gfp, int *err, |
1da177e4 LT |
286 | struct sctp_chunk **err_chk_p); |
287 | int 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. */ | |
295 | extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; | |
296 | ||
297 | ||
298 | /* Get the size of a DATA chunk payload. */ | |
299 | static 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 | ||
338 | enum { | |
339 | TSN_SIGN_BIT = (1<<31) | |
340 | }; | |
341 | ||
342 | static inline int TSN_lt(__u32 s, __u32 t) | |
343 | { | |
a02cec21 | 344 | return ((s) - (t)) & TSN_SIGN_BIT; |
1da177e4 LT |
345 | } |
346 | ||
347 | static inline int TSN_lte(__u32 s, __u32 t) | |
348 | { | |
a02cec21 | 349 | return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); |
1da177e4 LT |
350 | } |
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 | */ | |
362 | enum { | |
363 | SSN_SIGN_BIT = (1<<15) | |
364 | }; | |
365 | ||
366 | static inline int SSN_lt(__u16 s, __u16 t) | |
367 | { | |
a02cec21 | 368 | return ((s) - (t)) & SSN_SIGN_BIT; |
1da177e4 LT |
369 | } |
370 | ||
371 | static inline int SSN_lte(__u16 s, __u16 t) | |
372 | { | |
a02cec21 | 373 | return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); |
1da177e4 LT |
374 | } |
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 | */ | |
381 | enum { | |
382 | ADDIP_SERIAL_SIGN_BIT = (1<<31) | |
383 | }; | |
384 | ||
385 | static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) | |
386 | { | |
a02cec21 | 387 | return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); |
1da177e4 LT |
388 | } |
389 | ||
1da177e4 LT |
390 | /* Check VTAG of the packet matches the sender's own tag. */ |
391 | static inline int | |
392 | sctp_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 | ||
047a2428 JF |
407 | /* 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. | |
1da177e4 LT |
409 | */ |
410 | static inline int | |
411 | sctp_vtag_verify_either(const struct sctp_chunk *chunk, | |
412 | const struct sctp_association *asoc) | |
413 | { | |
047a2428 | 414 | /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 |
1da177e4 | 415 | * |
047a2428 JF |
416 | * 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. | |
1da177e4 | 424 | * |
047a2428 JF |
425 | * 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. | |
1da177e4 | 434 | */ |
047a2428 JF |
435 | if ((!sctp_test_T_bit(chunk) && |
436 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || | |
52688d6e | 437 | (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && |
047a2428 | 438 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { |
1da177e4 LT |
439 | return 1; |
440 | } | |
441 | ||
442 | return 0; | |
443 | } | |
444 | ||
445 | #endif /* __sctp_sm_h__ */ |