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, see 25 * <http://www.gnu.org/licenses/>. 26 * 27 * Please send any bug reports or fixes you make to the 28 * email addresses: 29 * lksctp developers <linux-sctp@vger.kernel.org> 30 * 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> 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 73 typedef sctp_disposition_t (sctp_state_fn_t) (struct net *, 74 const struct sctp_endpoint *, 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; 111 sctp_state_fn_t sctp_sf_operr_notify; 112 sctp_state_fn_t sctp_sf_t1_init_timer_expire; 113 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 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; 122 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 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; 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; 131 sctp_state_fn_t sctp_sf_do_5_2_3_initack; 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; 141 sctp_state_fn_t sctp_sf_eat_auth; 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. */ 162 sctp_state_fn_t sctp_sf_do_no_pending_tsn; 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); 175 const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, 176 sctp_event_t, 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 *, 182 gfp_t gfp); 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 *, 189 gfp_t gfp, int vparam_len); 190 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, 191 const struct sctp_chunk *, 192 const gfp_t gfp, 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 *); 214 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); 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 *, 222 struct msghdr *, size_t msg_len); 223 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, 224 const struct sctp_chunk *, 225 const __u8 *, 226 const size_t ); 227 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, 228 const struct sctp_chunk *, 229 struct sctp_paramhdr *); 230 struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, 231 const struct sctp_chunk *); 232 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, 233 const struct sctp_transport *); 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, 240 __be16 cause_code, 241 const void *payload, 242 size_t paylen, 243 size_t reserve_tail); 244 245 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 246 union sctp_addr *, 247 struct sockaddr *, 248 int, __be16); 249 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 250 union sctp_addr *addr); 251 bool sctp_verify_asconf(const struct sctp_association *asoc, 252 struct sctp_chunk *chunk, bool addr_param_needed, 253 struct sctp_paramhdr **errp); 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); 261 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); 262 263 void sctp_chunk_assign_tsn(struct sctp_chunk *); 264 void sctp_chunk_assign_ssn(struct sctp_chunk *); 265 266 /* Prototypes for statetable processing. */ 267 268 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 269 sctp_state_t state, 270 struct sctp_endpoint *, 271 struct sctp_association *asoc, 272 void *event_arg, 273 gfp_t gfp); 274 275 /* 2nd level prototypes */ 276 void sctp_generate_t3_rtx_event(unsigned long peer); 277 void sctp_generate_heartbeat_event(unsigned long peer); 278 void sctp_generate_proto_unreach_event(unsigned long peer); 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 *, 284 struct sctp_chunk *, 285 gfp_t gfp, int *err, 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 { 344 return ((s) - (t)) & TSN_SIGN_BIT; 345 } 346 347 static inline int TSN_lte(__u32 s, __u32 t) 348 { 349 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 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 { 368 return ((s) - (t)) & SSN_SIGN_BIT; 369 } 370 371 static inline int SSN_lte(__u16 s, __u16 t) 372 { 373 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); 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 { 387 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); 388 } 389 390 /* 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 } 406 407 /* 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. 409 */ 410 static inline int 411 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 412 const struct sctp_association *asoc) 413 { 414 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 415 * 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. 424 * 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. 434 */ 435 if ((!sctp_test_T_bit(chunk) && 436 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 437 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 438 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 439 return 1; 440 } 441 442 return 0; 443 } 444 445 #endif /* __sctp_sm_h__ */ 446