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_heartbeat(const struct sctp_association *, 238 const struct sctp_transport *); 239 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, 240 const struct sctp_chunk *, 241 const void *payload, 242 const size_t paylen); 243 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, 244 const struct sctp_chunk *chunk, 245 __be16 cause_code, 246 const void *payload, 247 size_t paylen, 248 size_t reserve_tail); 249 250 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 251 union sctp_addr *, 252 struct sockaddr *, 253 int, __be16); 254 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 255 union sctp_addr *addr); 256 int sctp_verify_asconf(const struct sctp_association *asoc, 257 struct sctp_paramhdr *param_hdr, void *chunk_end, 258 struct sctp_paramhdr **errp); 259 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 260 struct sctp_chunk *asconf); 261 int sctp_process_asconf_ack(struct sctp_association *asoc, 262 struct sctp_chunk *asconf_ack); 263 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 264 __u32 new_cum_tsn, size_t nstreams, 265 struct sctp_fwdtsn_skip *skiplist); 266 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); 267 268 void sctp_chunk_assign_tsn(struct sctp_chunk *); 269 void sctp_chunk_assign_ssn(struct sctp_chunk *); 270 271 /* Prototypes for statetable processing. */ 272 273 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 274 sctp_state_t state, 275 struct sctp_endpoint *, 276 struct sctp_association *asoc, 277 void *event_arg, 278 gfp_t gfp); 279 280 /* 2nd level prototypes */ 281 void sctp_generate_t3_rtx_event(unsigned long peer); 282 void sctp_generate_heartbeat_event(unsigned long peer); 283 void sctp_generate_proto_unreach_event(unsigned long peer); 284 285 void sctp_ootb_pkt_free(struct sctp_packet *); 286 287 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, 288 const struct sctp_association *, 289 struct sctp_chunk *, 290 gfp_t gfp, int *err, 291 struct sctp_chunk **err_chk_p); 292 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, 293 struct sockaddr_storage*, int); 294 295 /* 3rd level prototypes */ 296 __u32 sctp_generate_tag(const struct sctp_endpoint *); 297 __u32 sctp_generate_tsn(const struct sctp_endpoint *); 298 299 /* Extern declarations for major data structures. */ 300 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 301 302 303 /* Get the size of a DATA chunk payload. */ 304 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 305 { 306 __u16 size; 307 308 size = ntohs(chunk->chunk_hdr->length); 309 size -= sizeof(sctp_data_chunk_t); 310 311 return size; 312 } 313 314 /* Compare two TSNs */ 315 316 /* RFC 1982 - Serial Number Arithmetic 317 * 318 * 2. Comparison 319 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, 320 * in all other cases, s1 is not equal to s2. 321 * 322 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, 323 * and 324 * 325 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or 326 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) 327 * 328 * s1 is said to be greater than s2 if, and only if, s1 is not equal to 329 * s2, and 330 * 331 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or 332 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) 333 */ 334 335 /* 336 * RFC 2960 337 * 1.6 Serial Number Arithmetic 338 * 339 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial 340 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. 341 */ 342 343 enum { 344 TSN_SIGN_BIT = (1<<31) 345 }; 346 347 static inline int TSN_lt(__u32 s, __u32 t) 348 { 349 return ((s) - (t)) & TSN_SIGN_BIT; 350 } 351 352 static inline int TSN_lte(__u32 s, __u32 t) 353 { 354 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 355 } 356 357 /* Compare two SSNs */ 358 359 /* 360 * RFC 2960 361 * 1.6 Serial Number Arithmetic 362 * 363 * Comparisons and arithmetic on Stream Sequence Numbers in this document 364 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where 365 * SERIAL_BITS = 16. 366 */ 367 enum { 368 SSN_SIGN_BIT = (1<<15) 369 }; 370 371 static inline int SSN_lt(__u16 s, __u16 t) 372 { 373 return ((s) - (t)) & SSN_SIGN_BIT; 374 } 375 376 static inline int SSN_lte(__u16 s, __u16 t) 377 { 378 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); 379 } 380 381 /* 382 * ADDIP 3.1.1 383 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial 384 * Numbers wrap back to 0 after reaching 4294967295. 385 */ 386 enum { 387 ADDIP_SERIAL_SIGN_BIT = (1<<31) 388 }; 389 390 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) 391 { 392 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); 393 } 394 395 /* Check VTAG of the packet matches the sender's own tag. */ 396 static inline int 397 sctp_vtag_verify(const struct sctp_chunk *chunk, 398 const struct sctp_association *asoc) 399 { 400 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 401 * MUST ensure that the value in the Verification Tag field of 402 * the received SCTP packet matches its own Tag. If the received 403 * Verification Tag value does not match the receiver's own 404 * tag value, the receiver shall silently discard the packet... 405 */ 406 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 407 return 1; 408 409 return 0; 410 } 411 412 /* Check VTAG of the packet matches the sender's own tag and the T bit is 413 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 414 */ 415 static inline int 416 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 417 const struct sctp_association *asoc) 418 { 419 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 420 * 421 * B) The receiver of a ABORT MUST accept the packet 422 * if the Verification Tag field of the packet matches its own tag 423 * and the T bit is not set 424 * OR 425 * it is set to its peer's tag and the T bit is set in the Chunk 426 * Flags. 427 * Otherwise, the receiver MUST silently discard the packet 428 * and take no further action. 429 * 430 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 431 * if the Verification Tag field of the packet matches its own tag 432 * and the T bit is not set 433 * OR 434 * it is set to its peer's tag and the T bit is set in the Chunk 435 * Flags. 436 * Otherwise, the receiver MUST silently discard the packet 437 * and take no further action. An endpoint MUST ignore the 438 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 439 */ 440 if ((!sctp_test_T_bit(chunk) && 441 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 442 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 443 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 444 return 1; 445 } 446 447 return 0; 448 } 449 450 #endif /* __sctp_sm_h__ */ 451