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_operr_notify; 118 sctp_state_fn_t sctp_sf_t1_init_timer_expire; 119 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 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; 128 sctp_state_fn_t sctp_sf_do_ecn_cwr; 129 sctp_state_fn_t sctp_sf_do_ecne; 130 sctp_state_fn_t sctp_sf_ootb; 131 sctp_state_fn_t sctp_sf_pdiscard; 132 sctp_state_fn_t sctp_sf_violation; 133 sctp_state_fn_t sctp_sf_discard_chunk; 134 sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 135 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 136 sctp_state_fn_t sctp_sf_do_5_2_3_initack; 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, 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 int sctp_verify_asconf(const struct sctp_association *asoc, 250 struct sctp_paramhdr *param_hdr, void *chunk_end, 251 struct sctp_paramhdr **errp); 252 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 253 struct sctp_chunk *asconf); 254 int sctp_process_asconf_ack(struct sctp_association *asoc, 255 struct sctp_chunk *asconf_ack); 256 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 257 __u32 new_cum_tsn, size_t nstreams, 258 struct sctp_fwdtsn_skip *skiplist); 259 260 void sctp_chunk_assign_tsn(struct sctp_chunk *); 261 void sctp_chunk_assign_ssn(struct sctp_chunk *); 262 263 /* Prototypes for statetable processing. */ 264 265 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype, 266 sctp_state_t state, 267 struct sctp_endpoint *, 268 struct sctp_association *asoc, 269 void *event_arg, 270 gfp_t gfp); 271 272 /* 2nd level prototypes */ 273 void sctp_generate_t3_rtx_event(unsigned long peer); 274 void sctp_generate_heartbeat_event(unsigned long peer); 275 276 void sctp_ootb_pkt_free(struct sctp_packet *); 277 278 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, 279 const struct sctp_association *, 280 struct sctp_chunk *, 281 gfp_t gfp, int *err, 282 struct sctp_chunk **err_chk_p); 283 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, 284 struct sockaddr_storage*, int); 285 286 /* 3rd level prototypes */ 287 __u32 sctp_generate_tag(const struct sctp_endpoint *); 288 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 289 290 /* Extern declarations for major data structures. */ 291 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 292 293 294 /* Get the size of a DATA chunk payload. */ 295 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 296 { 297 __u16 size; 298 299 size = ntohs(chunk->chunk_hdr->length); 300 size -= sizeof(sctp_data_chunk_t); 301 302 return size; 303 } 304 305 /* Compare two TSNs */ 306 307 /* RFC 1982 - Serial Number Arithmetic 308 * 309 * 2. Comparison 310 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, 311 * in all other cases, s1 is not equal to s2. 312 * 313 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, 314 * and 315 * 316 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or 317 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) 318 * 319 * s1 is said to be greater than s2 if, and only if, s1 is not equal to 320 * s2, and 321 * 322 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or 323 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) 324 */ 325 326 /* 327 * RFC 2960 328 * 1.6 Serial Number Arithmetic 329 * 330 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial 331 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. 332 */ 333 334 enum { 335 TSN_SIGN_BIT = (1<<31) 336 }; 337 338 static inline int TSN_lt(__u32 s, __u32 t) 339 { 340 return (((s) - (t)) & TSN_SIGN_BIT); 341 } 342 343 static inline int TSN_lte(__u32 s, __u32 t) 344 { 345 return (((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT)); 346 } 347 348 /* Compare two SSNs */ 349 350 /* 351 * RFC 2960 352 * 1.6 Serial Number Arithmetic 353 * 354 * Comparisons and arithmetic on Stream Sequence Numbers in this document 355 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where 356 * SERIAL_BITS = 16. 357 */ 358 enum { 359 SSN_SIGN_BIT = (1<<15) 360 }; 361 362 static inline int SSN_lt(__u16 s, __u16 t) 363 { 364 return (((s) - (t)) & SSN_SIGN_BIT); 365 } 366 367 static inline int SSN_lte(__u16 s, __u16 t) 368 { 369 return (((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT)); 370 } 371 372 /* 373 * ADDIP 3.1.1 374 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial 375 * Numbers wrap back to 0 after reaching 4294967295. 376 */ 377 enum { 378 ADDIP_SERIAL_SIGN_BIT = (1<<31) 379 }; 380 381 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) 382 { 383 return (((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT)); 384 } 385 386 387 /* Run sctp_add_cmd() generating a BUG() if there is a failure. */ 388 static inline void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj) 389 { 390 if (unlikely(!sctp_add_cmd(seq, verb, obj))) 391 BUG(); 392 } 393 394 /* Check VTAG of the packet matches the sender's own tag. */ 395 static inline int 396 sctp_vtag_verify(const struct sctp_chunk *chunk, 397 const struct sctp_association *asoc) 398 { 399 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 400 * MUST ensure that the value in the Verification Tag field of 401 * the received SCTP packet matches its own Tag. If the received 402 * Verification Tag value does not match the receiver's own 403 * tag value, the receiver shall silently discard the packet... 404 */ 405 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 406 return 1; 407 408 return 0; 409 } 410 411 /* Check VTAG of the packet matches the sender's own tag and the T bit is 412 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 413 */ 414 static inline int 415 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 416 const struct sctp_association *asoc) 417 { 418 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 419 * 420 * B) The receiver of a ABORT MUST accept the packet 421 * if the Verification Tag field of the packet matches its own tag 422 * and the T bit is not set 423 * OR 424 * it is set to its peer's tag and the T bit is set in the Chunk 425 * Flags. 426 * Otherwise, the receiver MUST silently discard the packet 427 * and take no further action. 428 * 429 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 430 * if the Verification Tag field of the packet matches its own tag 431 * and the T bit is not set 432 * OR 433 * it is set to its peer's tag and the T bit is set in the Chunk 434 * Flags. 435 * Otherwise, the receiver MUST silently discard the packet 436 * and take no further action. An endpoint MUST ignore the 437 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 438 */ 439 if ((!sctp_test_T_bit(chunk) && 440 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 441 (sctp_test_T_bit(chunk) && 442 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 443 return 1; 444 } 445 446 return 0; 447 } 448 449 #endif /* __sctp_sm_h__ */ 450