1 /* SCTP kernel reference 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 reference Implementation 8 * 9 * These are definitions needed by the state machine. 10 * 11 * The SCTP reference 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 * The SCTP reference 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) (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; 117 sctp_state_fn_t sctp_sf_tabort_8_4_8; 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_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; 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; 137 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 138 sctp_state_fn_t sctp_sf_unk_chunk; 139 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 140 sctp_state_fn_t sctp_sf_cookie_echoed_err; 141 sctp_state_fn_t sctp_sf_do_asconf; 142 sctp_state_fn_t sctp_sf_do_asconf_ack; 143 sctp_state_fn_t sctp_sf_do_9_2_reshutack; 144 sctp_state_fn_t sctp_sf_eat_fwd_tsn; 145 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; 146 147 /* Prototypes for primitive event state functions. */ 148 sctp_state_fn_t sctp_sf_do_prm_asoc; 149 sctp_state_fn_t sctp_sf_do_prm_send; 150 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; 151 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; 152 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; 153 sctp_state_fn_t sctp_sf_do_9_1_prm_abort; 154 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; 155 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; 156 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; 157 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; 158 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; 159 sctp_state_fn_t sctp_sf_error_closed; 160 sctp_state_fn_t sctp_sf_error_shutdown; 161 sctp_state_fn_t sctp_sf_ignore_primitive; 162 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; 163 sctp_state_fn_t sctp_sf_do_prm_asconf; 164 165 /* Prototypes for other event state functions. */ 166 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 167 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 168 sctp_state_fn_t sctp_sf_ignore_other; 169 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 170 171 /* Prototypes for timeout event state functions. */ 172 sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 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); 178 const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t, 179 sctp_state_t, 180 sctp_subtype_t); 181 int sctp_chunk_iif(const struct sctp_chunk *); 182 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, 183 struct sctp_chunk *, 184 gfp_t gfp); 185 __u32 sctp_generate_verification_tag(void); 186 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); 187 188 /* Prototypes for chunk-building functions. */ 189 struct sctp_chunk *sctp_make_init(const struct sctp_association *, 190 const struct sctp_bind_addr *, 191 gfp_t gfp, int vparam_len); 192 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, 193 const struct sctp_chunk *, 194 const gfp_t gfp, 195 const int unkparam_len); 196 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, 197 const struct sctp_chunk *); 198 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, 199 const struct sctp_chunk *); 200 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, 201 const __u32 lowest_tsn, 202 const struct sctp_chunk *); 203 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, 204 const struct sctp_sndrcvinfo *sinfo, 205 int len, const __u8 flags, 206 __u16 ssn); 207 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, 208 const __u32); 209 struct sctp_chunk *sctp_make_sack(const struct sctp_association *); 210 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 211 const struct sctp_chunk *chunk); 212 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 213 const struct sctp_chunk *); 214 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, 215 const struct sctp_chunk *); 216 void sctp_init_cause(struct sctp_chunk *, __be16 cause, const void *, size_t); 217 struct sctp_chunk *sctp_make_abort(const struct sctp_association *, 218 const struct sctp_chunk *, 219 const size_t hint); 220 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, 221 const struct sctp_chunk *, 222 __u32 tsn); 223 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, 224 const struct msghdr *, size_t msg_len); 225 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, 226 const struct sctp_chunk *, 227 const __u8 *, 228 const size_t ); 229 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, 230 const struct sctp_transport *, 231 const void *payload, 232 const size_t paylen); 233 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, 234 const struct sctp_chunk *, 235 const void *payload, 236 const size_t paylen); 237 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, 238 const struct sctp_chunk *chunk, 239 __be16 cause_code, 240 const void *payload, 241 size_t paylen); 242 243 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 244 union sctp_addr *, 245 struct sockaddr *, 246 int, __be16); 247 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 248 union sctp_addr *addr); 249 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 250 struct sctp_chunk *asconf); 251 int sctp_process_asconf_ack(struct sctp_association *asoc, 252 struct sctp_chunk *asconf_ack); 253 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 254 __u32 new_cum_tsn, size_t nstreams, 255 struct sctp_fwdtsn_skip *skiplist); 256 257 void sctp_chunk_assign_tsn(struct sctp_chunk *); 258 void sctp_chunk_assign_ssn(struct sctp_chunk *); 259 260 /* Prototypes for statetable processing. */ 261 262 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype, 263 sctp_state_t state, 264 struct sctp_endpoint *, 265 struct sctp_association *asoc, 266 void *event_arg, 267 gfp_t gfp); 268 269 /* 2nd level prototypes */ 270 void sctp_generate_t3_rtx_event(unsigned long peer); 271 void sctp_generate_heartbeat_event(unsigned long peer); 272 273 void sctp_ootb_pkt_free(struct sctp_packet *); 274 275 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, 276 const struct sctp_association *, 277 struct sctp_chunk *, 278 gfp_t gfp, int *err, 279 struct sctp_chunk **err_chk_p); 280 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, 281 struct sockaddr_storage*, int); 282 283 /* 3rd level prototypes */ 284 __u32 sctp_generate_tag(const struct sctp_endpoint *); 285 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 286 287 /* Extern declarations for major data structures. */ 288 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 289 290 291 /* Get the size of a DATA chunk payload. */ 292 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 293 { 294 __u16 size; 295 296 size = ntohs(chunk->chunk_hdr->length); 297 size -= sizeof(sctp_data_chunk_t); 298 299 return size; 300 } 301 302 /* Compare two TSNs */ 303 304 /* RFC 1982 - Serial Number Arithmetic 305 * 306 * 2. Comparison 307 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, 308 * in all other cases, s1 is not equal to s2. 309 * 310 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, 311 * and 312 * 313 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or 314 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) 315 * 316 * s1 is said to be greater than s2 if, and only if, s1 is not equal to 317 * s2, and 318 * 319 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or 320 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) 321 */ 322 323 /* 324 * RFC 2960 325 * 1.6 Serial Number Arithmetic 326 * 327 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial 328 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. 329 */ 330 331 enum { 332 TSN_SIGN_BIT = (1<<31) 333 }; 334 335 static inline int TSN_lt(__u32 s, __u32 t) 336 { 337 return (((s) - (t)) & TSN_SIGN_BIT); 338 } 339 340 static inline int TSN_lte(__u32 s, __u32 t) 341 { 342 return (((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT)); 343 } 344 345 /* Compare two SSNs */ 346 347 /* 348 * RFC 2960 349 * 1.6 Serial Number Arithmetic 350 * 351 * Comparisons and arithmetic on Stream Sequence Numbers in this document 352 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where 353 * SERIAL_BITS = 16. 354 */ 355 enum { 356 SSN_SIGN_BIT = (1<<15) 357 }; 358 359 static inline int SSN_lt(__u16 s, __u16 t) 360 { 361 return (((s) - (t)) & SSN_SIGN_BIT); 362 } 363 364 static inline int SSN_lte(__u16 s, __u16 t) 365 { 366 return (((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT)); 367 } 368 369 /* 370 * ADDIP 3.1.1 371 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial 372 * Numbers wrap back to 0 after reaching 4294967295. 373 */ 374 enum { 375 ADDIP_SERIAL_SIGN_BIT = (1<<31) 376 }; 377 378 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) 379 { 380 return (((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT)); 381 } 382 383 384 /* Run sctp_add_cmd() generating a BUG() if there is a failure. */ 385 static inline void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj) 386 { 387 if (unlikely(!sctp_add_cmd(seq, verb, obj))) 388 BUG(); 389 } 390 391 /* Check VTAG of the packet matches the sender's own tag. */ 392 static inline int 393 sctp_vtag_verify(const struct sctp_chunk *chunk, 394 const struct sctp_association *asoc) 395 { 396 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 397 * MUST ensure that the value in the Verification Tag field of 398 * the received SCTP packet matches its own Tag. If the received 399 * Verification Tag value does not match the receiver's own 400 * tag value, the receiver shall silently discard the packet... 401 */ 402 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 403 return 1; 404 405 return 0; 406 } 407 408 /* Check VTAG of the packet matches the sender's own tag and the T bit is 409 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 410 */ 411 static inline int 412 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 413 const struct sctp_association *asoc) 414 { 415 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 416 * 417 * B) The receiver of a ABORT MUST accept the packet 418 * if the Verification Tag field of the packet matches its own tag 419 * and the T bit is not set 420 * OR 421 * it is set to its peer's tag and the T bit is set in the Chunk 422 * Flags. 423 * Otherwise, the receiver MUST silently discard the packet 424 * and take no further action. 425 * 426 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 427 * if the Verification Tag field of the packet matches its own tag 428 * and the T bit is not set 429 * OR 430 * it is set to its peer's tag and the T bit is set in the Chunk 431 * Flags. 432 * Otherwise, the receiver MUST silently discard the packet 433 * and take no further action. An endpoint MUST ignore the 434 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 435 */ 436 if ((!sctp_test_T_bit(chunk) && 437 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 438 (sctp_test_T_bit(chunk) && 439 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 440 return 1; 441 } 442 443 return 0; 444 } 445 446 #endif /* __sctp_sm_h__ */ 447