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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; | |
2040d3d7 | 138 | sctp_state_fn_t sctp_sf_do_reconf; |
1da177e4 LT |
139 | sctp_state_fn_t sctp_sf_do_9_2_reshutack; |
140 | sctp_state_fn_t sctp_sf_eat_fwd_tsn; | |
141 | sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; | |
bbd0d598 | 142 | sctp_state_fn_t sctp_sf_eat_auth; |
1da177e4 LT |
143 | |
144 | /* Prototypes for primitive event state functions. */ | |
145 | sctp_state_fn_t sctp_sf_do_prm_asoc; | |
146 | sctp_state_fn_t sctp_sf_do_prm_send; | |
147 | sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; | |
148 | sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; | |
149 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; | |
150 | sctp_state_fn_t sctp_sf_do_9_1_prm_abort; | |
151 | sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; | |
152 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; | |
153 | sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; | |
154 | sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; | |
155 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; | |
156 | sctp_state_fn_t sctp_sf_error_closed; | |
157 | sctp_state_fn_t sctp_sf_error_shutdown; | |
158 | sctp_state_fn_t sctp_sf_ignore_primitive; | |
159 | sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; | |
160 | sctp_state_fn_t sctp_sf_do_prm_asconf; | |
7a090b04 | 161 | sctp_state_fn_t sctp_sf_do_prm_reconf; |
1da177e4 LT |
162 | |
163 | /* Prototypes for other event state functions. */ | |
e1cdd553 | 164 | sctp_state_fn_t sctp_sf_do_no_pending_tsn; |
1da177e4 LT |
165 | sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; |
166 | sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; | |
167 | sctp_state_fn_t sctp_sf_ignore_other; | |
168 | sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; | |
169 | ||
170 | /* Prototypes for timeout event state functions. */ | |
171 | sctp_state_fn_t sctp_sf_do_6_3_3_rtx; | |
7b9438de | 172 | sctp_state_fn_t sctp_sf_send_reconf; |
1da177e4 LT |
173 | sctp_state_fn_t sctp_sf_do_6_2_sack; |
174 | sctp_state_fn_t sctp_sf_autoclose_timer_expire; | |
175 | ||
176 | /* Prototypes for utility support functions. */ | |
177 | __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); | |
55e26eb9 EB |
178 | const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, |
179 | sctp_event_t, | |
1da177e4 LT |
180 | sctp_state_t, |
181 | sctp_subtype_t); | |
182 | int sctp_chunk_iif(const struct sctp_chunk *); | |
183 | struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, | |
184 | struct sctp_chunk *, | |
dd0fc66f | 185 | gfp_t gfp); |
1da177e4 LT |
186 | __u32 sctp_generate_verification_tag(void); |
187 | void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); | |
188 | ||
189 | /* Prototypes for chunk-building functions. */ | |
190 | struct sctp_chunk *sctp_make_init(const struct sctp_association *, | |
191 | const struct sctp_bind_addr *, | |
dd0fc66f | 192 | gfp_t gfp, int vparam_len); |
1da177e4 LT |
193 | struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, |
194 | const struct sctp_chunk *, | |
dd0fc66f | 195 | const gfp_t gfp, |
1da177e4 LT |
196 | const int unkparam_len); |
197 | struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, | |
198 | const struct sctp_chunk *); | |
199 | struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, | |
200 | const struct sctp_chunk *); | |
201 | struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, | |
202 | const __u32 lowest_tsn, | |
203 | const struct sctp_chunk *); | |
204 | struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, | |
205 | const struct sctp_sndrcvinfo *sinfo, | |
206 | int len, const __u8 flags, | |
cea8768f | 207 | __u16 ssn, gfp_t gfp); |
1da177e4 LT |
208 | struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, |
209 | const __u32); | |
210 | struct sctp_chunk *sctp_make_sack(const struct sctp_association *); | |
211 | struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, | |
212 | const struct sctp_chunk *chunk); | |
213 | struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, | |
214 | const struct sctp_chunk *); | |
215 | struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, | |
216 | const struct sctp_chunk *); | |
00f1c2df | 217 | void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); |
1da177e4 LT |
218 | struct sctp_chunk *sctp_make_abort(const struct sctp_association *, |
219 | const struct sctp_chunk *, | |
220 | const size_t hint); | |
221 | struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, | |
222 | const struct sctp_chunk *, | |
223 | __u32 tsn); | |
224 | struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, | |
6ce8e9ce | 225 | struct msghdr *, size_t msg_len); |
1da177e4 LT |
226 | struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, |
227 | const struct sctp_chunk *, | |
228 | const __u8 *, | |
229 | const size_t ); | |
ba016670 WY |
230 | struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, |
231 | const struct sctp_chunk *, | |
232 | struct sctp_paramhdr *); | |
de4594a5 NH |
233 | struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, |
234 | const struct sctp_chunk *); | |
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); | |
9de7922b DB |
254 | bool sctp_verify_asconf(const struct sctp_association *asoc, |
255 | struct sctp_chunk *chunk, bool addr_param_needed, | |
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); |
cc16f00f XL |
265 | struct sctp_chunk *sctp_make_strreset_req( |
266 | const struct sctp_association *asoc, | |
267 | __u16 stream_num, __u16 *stream_list, | |
268 | bool out, bool in); | |
c56480a1 XL |
269 | struct sctp_chunk *sctp_make_strreset_tsnreq( |
270 | const struct sctp_association *asoc); | |
78098117 XL |
271 | struct sctp_chunk *sctp_make_strreset_addstrm( |
272 | const struct sctp_association *asoc, | |
273 | __u16 out, __u16 in); | |
bd4b9f8b XL |
274 | struct sctp_chunk *sctp_make_strreset_resp( |
275 | const struct sctp_association *asoc, | |
276 | __u32 result, __u32 sn); | |
277 | struct sctp_chunk *sctp_make_strreset_tsnresp( | |
278 | struct sctp_association *asoc, | |
279 | __u32 result, __u32 sn, | |
280 | __u32 sender_tsn, __u32 receiver_tsn); | |
ea625043 XL |
281 | bool sctp_verify_reconf(const struct sctp_association *asoc, |
282 | struct sctp_chunk *chunk, | |
283 | struct sctp_paramhdr **errp); | |
1da177e4 LT |
284 | void sctp_chunk_assign_tsn(struct sctp_chunk *); |
285 | void sctp_chunk_assign_ssn(struct sctp_chunk *); | |
286 | ||
81054476 XL |
287 | /* Prototypes for stream-processing functions. */ |
288 | struct sctp_chunk *sctp_process_strreset_outreq( | |
289 | struct sctp_association *asoc, | |
290 | union sctp_params param, | |
291 | struct sctp_ulpevent **evp); | |
16e1a919 XL |
292 | struct sctp_chunk *sctp_process_strreset_inreq( |
293 | struct sctp_association *asoc, | |
294 | union sctp_params param, | |
295 | struct sctp_ulpevent **evp); | |
692787ce XL |
296 | struct sctp_chunk *sctp_process_strreset_tsnreq( |
297 | struct sctp_association *asoc, | |
298 | union sctp_params param, | |
299 | struct sctp_ulpevent **evp); | |
50a41591 XL |
300 | struct sctp_chunk *sctp_process_strreset_addstrm_out( |
301 | struct sctp_association *asoc, | |
302 | union sctp_params param, | |
303 | struct sctp_ulpevent **evp); | |
81054476 | 304 | |
1da177e4 LT |
305 | /* Prototypes for statetable processing. */ |
306 | ||
55e26eb9 | 307 | int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, |
1da177e4 LT |
308 | sctp_state_t state, |
309 | struct sctp_endpoint *, | |
310 | struct sctp_association *asoc, | |
311 | void *event_arg, | |
dd0fc66f | 312 | gfp_t gfp); |
1da177e4 LT |
313 | |
314 | /* 2nd level prototypes */ | |
315 | void sctp_generate_t3_rtx_event(unsigned long peer); | |
316 | void sctp_generate_heartbeat_event(unsigned long peer); | |
7b9438de | 317 | void sctp_generate_reconf_event(unsigned long peer); |
50b5d6ad | 318 | void sctp_generate_proto_unreach_event(unsigned long peer); |
1da177e4 LT |
319 | |
320 | void sctp_ootb_pkt_free(struct sctp_packet *); | |
321 | ||
322 | struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, | |
323 | const struct sctp_association *, | |
3182cd84 | 324 | struct sctp_chunk *, |
dd0fc66f | 325 | gfp_t gfp, int *err, |
1da177e4 LT |
326 | struct sctp_chunk **err_chk_p); |
327 | int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, | |
328 | struct sockaddr_storage*, int); | |
329 | ||
330 | /* 3rd level prototypes */ | |
331 | __u32 sctp_generate_tag(const struct sctp_endpoint *); | |
332 | __u32 sctp_generate_tsn(const struct sctp_endpoint *); | |
333 | ||
334 | /* Extern declarations for major data structures. */ | |
335 | extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; | |
336 | ||
337 | ||
338 | /* Get the size of a DATA chunk payload. */ | |
339 | static inline __u16 sctp_data_size(struct sctp_chunk *chunk) | |
340 | { | |
341 | __u16 size; | |
342 | ||
343 | size = ntohs(chunk->chunk_hdr->length); | |
344 | size -= sizeof(sctp_data_chunk_t); | |
345 | ||
346 | return size; | |
347 | } | |
348 | ||
349 | /* Compare two TSNs */ | |
182691d0 MRL |
350 | #define TSN_lt(a,b) \ |
351 | (typecheck(__u32, a) && \ | |
352 | typecheck(__u32, b) && \ | |
353 | ((__s32)((a) - (b)) < 0)) | |
1da177e4 | 354 | |
182691d0 MRL |
355 | #define TSN_lte(a,b) \ |
356 | (typecheck(__u32, a) && \ | |
357 | typecheck(__u32, b) && \ | |
358 | ((__s32)((a) - (b)) <= 0)) | |
1da177e4 LT |
359 | |
360 | /* Compare two SSNs */ | |
182691d0 MRL |
361 | #define SSN_lt(a,b) \ |
362 | (typecheck(__u16, a) && \ | |
363 | typecheck(__u16, b) && \ | |
364 | ((__s16)((a) - (b)) < 0)) | |
365 | ||
366 | /* ADDIP 3.1.1 */ | |
367 | #define ADDIP_SERIAL_gte(a,b) \ | |
368 | (typecheck(__u32, a) && \ | |
369 | typecheck(__u32, b) && \ | |
370 | ((__s32)((b) - (a)) <= 0)) | |
1da177e4 | 371 | |
1da177e4 LT |
372 | /* Check VTAG of the packet matches the sender's own tag. */ |
373 | static inline int | |
374 | sctp_vtag_verify(const struct sctp_chunk *chunk, | |
375 | const struct sctp_association *asoc) | |
376 | { | |
377 | /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint | |
378 | * MUST ensure that the value in the Verification Tag field of | |
379 | * the received SCTP packet matches its own Tag. If the received | |
380 | * Verification Tag value does not match the receiver's own | |
381 | * tag value, the receiver shall silently discard the packet... | |
382 | */ | |
383 | if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) | |
384 | return 1; | |
385 | ||
386 | return 0; | |
387 | } | |
388 | ||
047a2428 JF |
389 | /* Check VTAG of the packet matches the sender's own tag and the T bit is |
390 | * not set, OR its peer's tag and the T bit is set in the Chunk Flags. | |
1da177e4 LT |
391 | */ |
392 | static inline int | |
393 | sctp_vtag_verify_either(const struct sctp_chunk *chunk, | |
394 | const struct sctp_association *asoc) | |
395 | { | |
047a2428 | 396 | /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 |
1da177e4 | 397 | * |
047a2428 JF |
398 | * B) The receiver of a ABORT MUST accept the packet |
399 | * if the Verification Tag field of the packet matches its own tag | |
400 | * and the T bit is not set | |
401 | * OR | |
402 | * it is set to its peer's tag and the T bit is set in the Chunk | |
403 | * Flags. | |
404 | * Otherwise, the receiver MUST silently discard the packet | |
405 | * and take no further action. | |
1da177e4 | 406 | * |
047a2428 JF |
407 | * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet |
408 | * if the Verification Tag field of the packet matches its own tag | |
409 | * and the T bit is not set | |
410 | * OR | |
411 | * it is set to its peer's tag and the T bit is set in the Chunk | |
412 | * Flags. | |
413 | * Otherwise, the receiver MUST silently discard the packet | |
414 | * and take no further action. An endpoint MUST ignore the | |
415 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. | |
1da177e4 | 416 | */ |
047a2428 JF |
417 | if ((!sctp_test_T_bit(chunk) && |
418 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || | |
52688d6e | 419 | (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && |
047a2428 | 420 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { |
1da177e4 LT |
421 | return 1; |
422 | } | |
423 | ||
424 | return 0; | |
425 | } | |
426 | ||
427 | #endif /* __sctp_sm_h__ */ |