| 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 Intel Corp. |
| 6 | * |
| 7 | * This file is part of the SCTP kernel implementation |
| 8 | * |
| 9 | * These are definitions needed by the state machine. |
| 10 | * |
| 11 | * This SCTP implementation is free software; |
| 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 | * |
| 17 | * This SCTP implementation is distributed in the hope that it |
| 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) (struct net *, |
| 81 | const struct sctp_endpoint *, |
| 82 | const struct sctp_association *, |
| 83 | const sctp_subtype_t type, |
| 84 | void *arg, |
| 85 | sctp_cmd_seq_t *); |
| 86 | typedef void (sctp_timer_event_t) (unsigned long); |
| 87 | typedef struct { |
| 88 | sctp_state_fn_t *fn; |
| 89 | const char *name; |
| 90 | } sctp_sm_table_entry_t; |
| 91 | |
| 92 | /* A naming convention of "sctp_sf_xxx" applies to all the state functions |
| 93 | * currently in use. |
| 94 | */ |
| 95 | |
| 96 | /* Prototypes for generic state functions. */ |
| 97 | sctp_state_fn_t sctp_sf_not_impl; |
| 98 | sctp_state_fn_t sctp_sf_bug; |
| 99 | |
| 100 | /* Prototypes for gener timer state functions. */ |
| 101 | sctp_state_fn_t sctp_sf_timer_ignore; |
| 102 | |
| 103 | /* Prototypes for chunk state functions. */ |
| 104 | sctp_state_fn_t sctp_sf_do_9_1_abort; |
| 105 | sctp_state_fn_t sctp_sf_cookie_wait_abort; |
| 106 | sctp_state_fn_t sctp_sf_cookie_echoed_abort; |
| 107 | sctp_state_fn_t sctp_sf_shutdown_pending_abort; |
| 108 | sctp_state_fn_t sctp_sf_shutdown_sent_abort; |
| 109 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; |
| 110 | sctp_state_fn_t sctp_sf_do_5_1B_init; |
| 111 | sctp_state_fn_t sctp_sf_do_5_1C_ack; |
| 112 | sctp_state_fn_t sctp_sf_do_5_1D_ce; |
| 113 | sctp_state_fn_t sctp_sf_do_5_1E_ca; |
| 114 | sctp_state_fn_t sctp_sf_do_4_C; |
| 115 | sctp_state_fn_t sctp_sf_eat_data_6_2; |
| 116 | sctp_state_fn_t sctp_sf_eat_data_fast_4_4; |
| 117 | sctp_state_fn_t sctp_sf_eat_sack_6_2; |
| 118 | sctp_state_fn_t sctp_sf_operr_notify; |
| 119 | sctp_state_fn_t sctp_sf_t1_init_timer_expire; |
| 120 | sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; |
| 121 | sctp_state_fn_t sctp_sf_t2_timer_expire; |
| 122 | sctp_state_fn_t sctp_sf_t4_timer_expire; |
| 123 | sctp_state_fn_t sctp_sf_t5_timer_expire; |
| 124 | sctp_state_fn_t sctp_sf_sendbeat_8_3; |
| 125 | sctp_state_fn_t sctp_sf_beat_8_3; |
| 126 | sctp_state_fn_t sctp_sf_backbeat_8_3; |
| 127 | sctp_state_fn_t sctp_sf_do_9_2_final; |
| 128 | sctp_state_fn_t sctp_sf_do_9_2_shutdown; |
| 129 | sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; |
| 130 | sctp_state_fn_t sctp_sf_do_ecn_cwr; |
| 131 | sctp_state_fn_t sctp_sf_do_ecne; |
| 132 | sctp_state_fn_t sctp_sf_ootb; |
| 133 | sctp_state_fn_t sctp_sf_pdiscard; |
| 134 | sctp_state_fn_t sctp_sf_violation; |
| 135 | sctp_state_fn_t sctp_sf_discard_chunk; |
| 136 | sctp_state_fn_t sctp_sf_do_5_2_1_siminit; |
| 137 | sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; |
| 138 | sctp_state_fn_t sctp_sf_do_5_2_3_initack; |
| 139 | sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; |
| 140 | sctp_state_fn_t sctp_sf_unk_chunk; |
| 141 | sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; |
| 142 | sctp_state_fn_t sctp_sf_cookie_echoed_err; |
| 143 | sctp_state_fn_t sctp_sf_do_asconf; |
| 144 | sctp_state_fn_t sctp_sf_do_asconf_ack; |
| 145 | sctp_state_fn_t sctp_sf_do_9_2_reshutack; |
| 146 | sctp_state_fn_t sctp_sf_eat_fwd_tsn; |
| 147 | sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; |
| 148 | sctp_state_fn_t sctp_sf_eat_auth; |
| 149 | |
| 150 | /* Prototypes for primitive event state functions. */ |
| 151 | sctp_state_fn_t sctp_sf_do_prm_asoc; |
| 152 | sctp_state_fn_t sctp_sf_do_prm_send; |
| 153 | sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; |
| 154 | sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; |
| 155 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; |
| 156 | sctp_state_fn_t sctp_sf_do_9_1_prm_abort; |
| 157 | sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; |
| 158 | sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; |
| 159 | sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; |
| 160 | sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; |
| 161 | sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; |
| 162 | sctp_state_fn_t sctp_sf_error_closed; |
| 163 | sctp_state_fn_t sctp_sf_error_shutdown; |
| 164 | sctp_state_fn_t sctp_sf_ignore_primitive; |
| 165 | sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; |
| 166 | sctp_state_fn_t sctp_sf_do_prm_asconf; |
| 167 | |
| 168 | /* Prototypes for other event state functions. */ |
| 169 | sctp_state_fn_t sctp_sf_do_no_pending_tsn; |
| 170 | sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; |
| 171 | sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; |
| 172 | sctp_state_fn_t sctp_sf_ignore_other; |
| 173 | sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; |
| 174 | |
| 175 | /* Prototypes for timeout event state functions. */ |
| 176 | sctp_state_fn_t sctp_sf_do_6_3_3_rtx; |
| 177 | sctp_state_fn_t sctp_sf_do_6_2_sack; |
| 178 | sctp_state_fn_t sctp_sf_autoclose_timer_expire; |
| 179 | |
| 180 | /* Prototypes for utility support functions. */ |
| 181 | __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); |
| 182 | const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, |
| 183 | sctp_event_t, |
| 184 | sctp_state_t, |
| 185 | sctp_subtype_t); |
| 186 | int sctp_chunk_iif(const struct sctp_chunk *); |
| 187 | struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, |
| 188 | struct sctp_chunk *, |
| 189 | gfp_t gfp); |
| 190 | __u32 sctp_generate_verification_tag(void); |
| 191 | void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); |
| 192 | |
| 193 | /* Prototypes for chunk-building functions. */ |
| 194 | struct sctp_chunk *sctp_make_init(const struct sctp_association *, |
| 195 | const struct sctp_bind_addr *, |
| 196 | gfp_t gfp, int vparam_len); |
| 197 | struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, |
| 198 | const struct sctp_chunk *, |
| 199 | const gfp_t gfp, |
| 200 | const int unkparam_len); |
| 201 | struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, |
| 202 | const struct sctp_chunk *); |
| 203 | struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, |
| 204 | const struct sctp_chunk *); |
| 205 | struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, |
| 206 | const __u32 lowest_tsn, |
| 207 | const struct sctp_chunk *); |
| 208 | struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, |
| 209 | const struct sctp_sndrcvinfo *sinfo, |
| 210 | int len, const __u8 flags, |
| 211 | __u16 ssn); |
| 212 | struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, |
| 213 | const __u32); |
| 214 | struct sctp_chunk *sctp_make_sack(const struct sctp_association *); |
| 215 | struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, |
| 216 | const struct sctp_chunk *chunk); |
| 217 | struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, |
| 218 | const struct sctp_chunk *); |
| 219 | struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, |
| 220 | const struct sctp_chunk *); |
| 221 | void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); |
| 222 | struct sctp_chunk *sctp_make_abort(const struct sctp_association *, |
| 223 | const struct sctp_chunk *, |
| 224 | const size_t hint); |
| 225 | struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, |
| 226 | const struct sctp_chunk *, |
| 227 | __u32 tsn); |
| 228 | struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, |
| 229 | const struct msghdr *, size_t msg_len); |
| 230 | struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, |
| 231 | const struct sctp_chunk *, |
| 232 | const __u8 *, |
| 233 | const size_t ); |
| 234 | struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, |
| 235 | const struct sctp_chunk *, |
| 236 | struct sctp_paramhdr *); |
| 237 | struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, |
| 238 | const struct sctp_chunk *); |
| 239 | struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, |
| 240 | const struct sctp_transport *); |
| 241 | struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, |
| 242 | const struct sctp_chunk *, |
| 243 | const void *payload, |
| 244 | const size_t paylen); |
| 245 | struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, |
| 246 | const struct sctp_chunk *chunk, |
| 247 | __be16 cause_code, |
| 248 | const void *payload, |
| 249 | size_t paylen, |
| 250 | size_t reserve_tail); |
| 251 | |
| 252 | struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, |
| 253 | union sctp_addr *, |
| 254 | struct sockaddr *, |
| 255 | int, __be16); |
| 256 | struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, |
| 257 | union sctp_addr *addr); |
| 258 | bool sctp_verify_asconf(const struct sctp_association *asoc, |
| 259 | struct sctp_chunk *chunk, bool addr_param_needed, |
| 260 | struct sctp_paramhdr **errp); |
| 261 | struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, |
| 262 | struct sctp_chunk *asconf); |
| 263 | int sctp_process_asconf_ack(struct sctp_association *asoc, |
| 264 | struct sctp_chunk *asconf_ack); |
| 265 | struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, |
| 266 | __u32 new_cum_tsn, size_t nstreams, |
| 267 | struct sctp_fwdtsn_skip *skiplist); |
| 268 | struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); |
| 269 | |
| 270 | void sctp_chunk_assign_tsn(struct sctp_chunk *); |
| 271 | void sctp_chunk_assign_ssn(struct sctp_chunk *); |
| 272 | |
| 273 | /* Prototypes for statetable processing. */ |
| 274 | |
| 275 | int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, |
| 276 | sctp_state_t state, |
| 277 | struct sctp_endpoint *, |
| 278 | struct sctp_association *asoc, |
| 279 | void *event_arg, |
| 280 | gfp_t gfp); |
| 281 | |
| 282 | /* 2nd level prototypes */ |
| 283 | void sctp_generate_t3_rtx_event(unsigned long peer); |
| 284 | void sctp_generate_heartbeat_event(unsigned long peer); |
| 285 | void sctp_generate_proto_unreach_event(unsigned long peer); |
| 286 | |
| 287 | void sctp_ootb_pkt_free(struct sctp_packet *); |
| 288 | |
| 289 | struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, |
| 290 | const struct sctp_association *, |
| 291 | struct sctp_chunk *, |
| 292 | gfp_t gfp, int *err, |
| 293 | struct sctp_chunk **err_chk_p); |
| 294 | int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, |
| 295 | struct sockaddr_storage*, int); |
| 296 | |
| 297 | /* 3rd level prototypes */ |
| 298 | __u32 sctp_generate_tag(const struct sctp_endpoint *); |
| 299 | __u32 sctp_generate_tsn(const struct sctp_endpoint *); |
| 300 | |
| 301 | /* Extern declarations for major data structures. */ |
| 302 | extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; |
| 303 | |
| 304 | |
| 305 | /* Get the size of a DATA chunk payload. */ |
| 306 | static inline __u16 sctp_data_size(struct sctp_chunk *chunk) |
| 307 | { |
| 308 | __u16 size; |
| 309 | |
| 310 | size = ntohs(chunk->chunk_hdr->length); |
| 311 | size -= sizeof(sctp_data_chunk_t); |
| 312 | |
| 313 | return size; |
| 314 | } |
| 315 | |
| 316 | /* Compare two TSNs */ |
| 317 | |
| 318 | /* RFC 1982 - Serial Number Arithmetic |
| 319 | * |
| 320 | * 2. Comparison |
| 321 | * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, |
| 322 | * in all other cases, s1 is not equal to s2. |
| 323 | * |
| 324 | * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, |
| 325 | * and |
| 326 | * |
| 327 | * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or |
| 328 | * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) |
| 329 | * |
| 330 | * s1 is said to be greater than s2 if, and only if, s1 is not equal to |
| 331 | * s2, and |
| 332 | * |
| 333 | * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or |
| 334 | * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) |
| 335 | */ |
| 336 | |
| 337 | /* |
| 338 | * RFC 2960 |
| 339 | * 1.6 Serial Number Arithmetic |
| 340 | * |
| 341 | * Comparisons and arithmetic on TSNs in this document SHOULD use Serial |
| 342 | * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. |
| 343 | */ |
| 344 | |
| 345 | enum { |
| 346 | TSN_SIGN_BIT = (1<<31) |
| 347 | }; |
| 348 | |
| 349 | static inline int TSN_lt(__u32 s, __u32 t) |
| 350 | { |
| 351 | return ((s) - (t)) & TSN_SIGN_BIT; |
| 352 | } |
| 353 | |
| 354 | static inline int TSN_lte(__u32 s, __u32 t) |
| 355 | { |
| 356 | return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); |
| 357 | } |
| 358 | |
| 359 | /* Compare two SSNs */ |
| 360 | |
| 361 | /* |
| 362 | * RFC 2960 |
| 363 | * 1.6 Serial Number Arithmetic |
| 364 | * |
| 365 | * Comparisons and arithmetic on Stream Sequence Numbers in this document |
| 366 | * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where |
| 367 | * SERIAL_BITS = 16. |
| 368 | */ |
| 369 | enum { |
| 370 | SSN_SIGN_BIT = (1<<15) |
| 371 | }; |
| 372 | |
| 373 | static inline int SSN_lt(__u16 s, __u16 t) |
| 374 | { |
| 375 | return ((s) - (t)) & SSN_SIGN_BIT; |
| 376 | } |
| 377 | |
| 378 | static inline int SSN_lte(__u16 s, __u16 t) |
| 379 | { |
| 380 | return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * ADDIP 3.1.1 |
| 385 | * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial |
| 386 | * Numbers wrap back to 0 after reaching 4294967295. |
| 387 | */ |
| 388 | enum { |
| 389 | ADDIP_SERIAL_SIGN_BIT = (1<<31) |
| 390 | }; |
| 391 | |
| 392 | static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) |
| 393 | { |
| 394 | return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); |
| 395 | } |
| 396 | |
| 397 | /* Check VTAG of the packet matches the sender's own tag. */ |
| 398 | static inline int |
| 399 | sctp_vtag_verify(const struct sctp_chunk *chunk, |
| 400 | const struct sctp_association *asoc) |
| 401 | { |
| 402 | /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint |
| 403 | * MUST ensure that the value in the Verification Tag field of |
| 404 | * the received SCTP packet matches its own Tag. If the received |
| 405 | * Verification Tag value does not match the receiver's own |
| 406 | * tag value, the receiver shall silently discard the packet... |
| 407 | */ |
| 408 | if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) |
| 409 | return 1; |
| 410 | |
| 411 | return 0; |
| 412 | } |
| 413 | |
| 414 | /* Check VTAG of the packet matches the sender's own tag and the T bit is |
| 415 | * not set, OR its peer's tag and the T bit is set in the Chunk Flags. |
| 416 | */ |
| 417 | static inline int |
| 418 | sctp_vtag_verify_either(const struct sctp_chunk *chunk, |
| 419 | const struct sctp_association *asoc) |
| 420 | { |
| 421 | /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 |
| 422 | * |
| 423 | * B) The receiver of a ABORT MUST accept the packet |
| 424 | * if the Verification Tag field of the packet matches its own tag |
| 425 | * and the T bit is not set |
| 426 | * OR |
| 427 | * it is set to its peer's tag and the T bit is set in the Chunk |
| 428 | * Flags. |
| 429 | * Otherwise, the receiver MUST silently discard the packet |
| 430 | * and take no further action. |
| 431 | * |
| 432 | * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet |
| 433 | * if the Verification Tag field of the packet matches its own tag |
| 434 | * and the T bit is not set |
| 435 | * OR |
| 436 | * it is set to its peer's tag and the T bit is set in the Chunk |
| 437 | * Flags. |
| 438 | * Otherwise, the receiver MUST silently discard the packet |
| 439 | * and take no further action. An endpoint MUST ignore the |
| 440 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. |
| 441 | */ |
| 442 | if ((!sctp_test_T_bit(chunk) && |
| 443 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || |
| 444 | (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && |
| 445 | (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { |
| 446 | return 1; |
| 447 | } |
| 448 | |
| 449 | return 0; |
| 450 | } |
| 451 | |
| 452 | #endif /* __sctp_sm_h__ */ |