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 <linux-sctp@vger.kernel.org> 31 * 32 * Written or modified by: 33 * La Monte H.P. Yarroll <piggy@acm.org> 34 * Karl Knutson <karl@athena.chicago.il.us> 35 * Xingang Guo <xingang.guo@intel.com> 36 * Jon Grimm <jgrimm@us.ibm.com> 37 * Dajiang Zhang <dajiang.zhang@nokia.com> 38 * Sridhar Samudrala <sri@us.ibm.com> 39 * Daisy Chang <daisyc@us.ibm.com> 40 * Ardelle Fan <ardelle.fan@intel.com> 41 * Kevin Gao <kevin.gao@intel.com> 42 */ 43 44 #include <linux/types.h> 45 #include <linux/compiler.h> 46 #include <linux/slab.h> 47 #include <linux/in.h> 48 #include <net/sctp/command.h> 49 #include <net/sctp/sctp.h> 50 51 #ifndef __sctp_sm_h__ 52 #define __sctp_sm_h__ 53 54 /* 55 * Possible values for the disposition are: 56 */ 57 typedef enum { 58 SCTP_DISPOSITION_DISCARD, /* No further processing. */ 59 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */ 60 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */ 61 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */ 62 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */ 63 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */ 64 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */ 65 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */ 66 SCTP_DISPOSITION_BUG, /* This is a bug. */ 67 } sctp_disposition_t; 68 69 typedef struct { 70 int name; 71 int action; 72 } sctp_sm_command_t; 73 74 typedef sctp_disposition_t (sctp_state_fn_t) (struct net *, 75 const struct sctp_endpoint *, 76 const struct sctp_association *, 77 const sctp_subtype_t type, 78 void *arg, 79 sctp_cmd_seq_t *); 80 typedef void (sctp_timer_event_t) (unsigned long); 81 typedef struct { 82 sctp_state_fn_t *fn; 83 const char *name; 84 } sctp_sm_table_entry_t; 85 86 /* A naming convention of "sctp_sf_xxx" applies to all the state functions 87 * currently in use. 88 */ 89 90 /* Prototypes for generic state functions. */ 91 sctp_state_fn_t sctp_sf_not_impl; 92 sctp_state_fn_t sctp_sf_bug; 93 94 /* Prototypes for gener timer state functions. */ 95 sctp_state_fn_t sctp_sf_timer_ignore; 96 97 /* Prototypes for chunk state functions. */ 98 sctp_state_fn_t sctp_sf_do_9_1_abort; 99 sctp_state_fn_t sctp_sf_cookie_wait_abort; 100 sctp_state_fn_t sctp_sf_cookie_echoed_abort; 101 sctp_state_fn_t sctp_sf_shutdown_pending_abort; 102 sctp_state_fn_t sctp_sf_shutdown_sent_abort; 103 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; 104 sctp_state_fn_t sctp_sf_do_5_1B_init; 105 sctp_state_fn_t sctp_sf_do_5_1C_ack; 106 sctp_state_fn_t sctp_sf_do_5_1D_ce; 107 sctp_state_fn_t sctp_sf_do_5_1E_ca; 108 sctp_state_fn_t sctp_sf_do_4_C; 109 sctp_state_fn_t sctp_sf_eat_data_6_2; 110 sctp_state_fn_t sctp_sf_eat_data_fast_4_4; 111 sctp_state_fn_t sctp_sf_eat_sack_6_2; 112 sctp_state_fn_t sctp_sf_operr_notify; 113 sctp_state_fn_t sctp_sf_t1_init_timer_expire; 114 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 115 sctp_state_fn_t sctp_sf_t2_timer_expire; 116 sctp_state_fn_t sctp_sf_t4_timer_expire; 117 sctp_state_fn_t sctp_sf_t5_timer_expire; 118 sctp_state_fn_t sctp_sf_sendbeat_8_3; 119 sctp_state_fn_t sctp_sf_beat_8_3; 120 sctp_state_fn_t sctp_sf_backbeat_8_3; 121 sctp_state_fn_t sctp_sf_do_9_2_final; 122 sctp_state_fn_t sctp_sf_do_9_2_shutdown; 123 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 124 sctp_state_fn_t sctp_sf_do_ecn_cwr; 125 sctp_state_fn_t sctp_sf_do_ecne; 126 sctp_state_fn_t sctp_sf_ootb; 127 sctp_state_fn_t sctp_sf_pdiscard; 128 sctp_state_fn_t sctp_sf_violation; 129 sctp_state_fn_t sctp_sf_discard_chunk; 130 sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 131 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 132 sctp_state_fn_t sctp_sf_do_5_2_3_initack; 133 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 134 sctp_state_fn_t sctp_sf_unk_chunk; 135 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 136 sctp_state_fn_t sctp_sf_cookie_echoed_err; 137 sctp_state_fn_t sctp_sf_do_asconf; 138 sctp_state_fn_t sctp_sf_do_asconf_ack; 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; 142 sctp_state_fn_t sctp_sf_eat_auth; 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; 161 162 /* Prototypes for other event state functions. */ 163 sctp_state_fn_t sctp_sf_do_no_pending_tsn; 164 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 165 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 166 sctp_state_fn_t sctp_sf_ignore_other; 167 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 168 169 /* Prototypes for timeout event state functions. */ 170 sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 171 sctp_state_fn_t sctp_sf_do_6_2_sack; 172 sctp_state_fn_t sctp_sf_autoclose_timer_expire; 173 174 /* Prototypes for utility support functions. */ 175 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); 176 const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, 177 sctp_event_t, 178 sctp_state_t, 179 sctp_subtype_t); 180 int sctp_chunk_iif(const struct sctp_chunk *); 181 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, 182 struct sctp_chunk *, 183 gfp_t gfp); 184 __u32 sctp_generate_verification_tag(void); 185 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); 186 187 /* Prototypes for chunk-building functions. */ 188 struct sctp_chunk *sctp_make_init(const struct sctp_association *, 189 const struct sctp_bind_addr *, 190 gfp_t gfp, int vparam_len); 191 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, 192 const struct sctp_chunk *, 193 const gfp_t gfp, 194 const int unkparam_len); 195 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, 196 const struct sctp_chunk *); 197 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, 198 const struct sctp_chunk *); 199 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, 200 const __u32 lowest_tsn, 201 const struct sctp_chunk *); 202 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, 203 const struct sctp_sndrcvinfo *sinfo, 204 int len, const __u8 flags, 205 __u16 ssn); 206 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, 207 const __u32); 208 struct sctp_chunk *sctp_make_sack(const struct sctp_association *); 209 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 210 const struct sctp_chunk *chunk); 211 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 212 const struct sctp_chunk *); 213 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, 214 const struct sctp_chunk *); 215 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); 216 struct sctp_chunk *sctp_make_abort(const struct sctp_association *, 217 const struct sctp_chunk *, 218 const size_t hint); 219 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, 220 const struct sctp_chunk *, 221 __u32 tsn); 222 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, 223 const struct msghdr *, size_t msg_len); 224 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, 225 const struct sctp_chunk *, 226 const __u8 *, 227 const size_t ); 228 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, 229 const struct sctp_chunk *, 230 struct sctp_paramhdr *); 231 struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, 232 const struct sctp_chunk *); 233 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, 234 const struct sctp_transport *); 235 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, 236 const struct sctp_chunk *, 237 const void *payload, 238 const size_t paylen); 239 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, 240 const struct sctp_chunk *chunk, 241 __be16 cause_code, 242 const void *payload, 243 size_t paylen, 244 size_t reserve_tail); 245 246 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 247 union sctp_addr *, 248 struct sockaddr *, 249 int, __be16); 250 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 251 union sctp_addr *addr); 252 int sctp_verify_asconf(const struct sctp_association *asoc, 253 struct sctp_paramhdr *param_hdr, void *chunk_end, 254 struct sctp_paramhdr **errp); 255 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 256 struct sctp_chunk *asconf); 257 int sctp_process_asconf_ack(struct sctp_association *asoc, 258 struct sctp_chunk *asconf_ack); 259 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 260 __u32 new_cum_tsn, size_t nstreams, 261 struct sctp_fwdtsn_skip *skiplist); 262 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); 263 264 void sctp_chunk_assign_tsn(struct sctp_chunk *); 265 void sctp_chunk_assign_ssn(struct sctp_chunk *); 266 267 /* Prototypes for statetable processing. */ 268 269 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 270 sctp_state_t state, 271 struct sctp_endpoint *, 272 struct sctp_association *asoc, 273 void *event_arg, 274 gfp_t gfp); 275 276 /* 2nd level prototypes */ 277 void sctp_generate_t3_rtx_event(unsigned long peer); 278 void sctp_generate_heartbeat_event(unsigned long peer); 279 void sctp_generate_proto_unreach_event(unsigned long peer); 280 281 void sctp_ootb_pkt_free(struct sctp_packet *); 282 283 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, 284 const struct sctp_association *, 285 struct sctp_chunk *, 286 gfp_t gfp, int *err, 287 struct sctp_chunk **err_chk_p); 288 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, 289 struct sockaddr_storage*, int); 290 291 /* 3rd level prototypes */ 292 __u32 sctp_generate_tag(const struct sctp_endpoint *); 293 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 294 295 /* Extern declarations for major data structures. */ 296 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 297 298 299 /* Get the size of a DATA chunk payload. */ 300 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 301 { 302 __u16 size; 303 304 size = ntohs(chunk->chunk_hdr->length); 305 size -= sizeof(sctp_data_chunk_t); 306 307 return size; 308 } 309 310 /* Compare two TSNs */ 311 312 /* RFC 1982 - Serial Number Arithmetic 313 * 314 * 2. Comparison 315 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, 316 * in all other cases, s1 is not equal to s2. 317 * 318 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, 319 * and 320 * 321 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or 322 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) 323 * 324 * s1 is said to be greater than s2 if, and only if, s1 is not equal to 325 * s2, and 326 * 327 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or 328 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) 329 */ 330 331 /* 332 * RFC 2960 333 * 1.6 Serial Number Arithmetic 334 * 335 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial 336 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. 337 */ 338 339 enum { 340 TSN_SIGN_BIT = (1<<31) 341 }; 342 343 static inline int TSN_lt(__u32 s, __u32 t) 344 { 345 return ((s) - (t)) & TSN_SIGN_BIT; 346 } 347 348 static inline int TSN_lte(__u32 s, __u32 t) 349 { 350 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 351 } 352 353 /* Compare two SSNs */ 354 355 /* 356 * RFC 2960 357 * 1.6 Serial Number Arithmetic 358 * 359 * Comparisons and arithmetic on Stream Sequence Numbers in this document 360 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where 361 * SERIAL_BITS = 16. 362 */ 363 enum { 364 SSN_SIGN_BIT = (1<<15) 365 }; 366 367 static inline int SSN_lt(__u16 s, __u16 t) 368 { 369 return ((s) - (t)) & SSN_SIGN_BIT; 370 } 371 372 static inline int SSN_lte(__u16 s, __u16 t) 373 { 374 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); 375 } 376 377 /* 378 * ADDIP 3.1.1 379 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial 380 * Numbers wrap back to 0 after reaching 4294967295. 381 */ 382 enum { 383 ADDIP_SERIAL_SIGN_BIT = (1<<31) 384 }; 385 386 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) 387 { 388 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); 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) && asoc->c.peer_vtag && 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