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 enum sctp_disposition { 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 }; 67 68 typedef enum sctp_disposition (sctp_state_fn_t) ( 69 struct net *net, 70 const struct sctp_endpoint *ep, 71 const struct sctp_association *asoc, 72 const union sctp_subtype type, 73 void *arg, 74 struct sctp_cmd_seq *commands); 75 typedef void (sctp_timer_event_t) (struct timer_list *); 76 struct sctp_sm_table_entry { 77 sctp_state_fn_t *fn; 78 const char *name; 79 }; 80 81 /* A naming convention of "sctp_sf_xxx" applies to all the state functions 82 * currently in use. 83 */ 84 85 /* Prototypes for generic state functions. */ 86 sctp_state_fn_t sctp_sf_not_impl; 87 sctp_state_fn_t sctp_sf_bug; 88 89 /* Prototypes for gener timer state functions. */ 90 sctp_state_fn_t sctp_sf_timer_ignore; 91 92 /* Prototypes for chunk state functions. */ 93 sctp_state_fn_t sctp_sf_do_9_1_abort; 94 sctp_state_fn_t sctp_sf_cookie_wait_abort; 95 sctp_state_fn_t sctp_sf_cookie_echoed_abort; 96 sctp_state_fn_t sctp_sf_shutdown_pending_abort; 97 sctp_state_fn_t sctp_sf_shutdown_sent_abort; 98 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; 99 sctp_state_fn_t sctp_sf_do_5_1B_init; 100 sctp_state_fn_t sctp_sf_do_5_1C_ack; 101 sctp_state_fn_t sctp_sf_do_5_1D_ce; 102 sctp_state_fn_t sctp_sf_do_5_1E_ca; 103 sctp_state_fn_t sctp_sf_do_4_C; 104 sctp_state_fn_t sctp_sf_eat_data_6_2; 105 sctp_state_fn_t sctp_sf_eat_data_fast_4_4; 106 sctp_state_fn_t sctp_sf_eat_sack_6_2; 107 sctp_state_fn_t sctp_sf_operr_notify; 108 sctp_state_fn_t sctp_sf_t1_init_timer_expire; 109 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 110 sctp_state_fn_t sctp_sf_t2_timer_expire; 111 sctp_state_fn_t sctp_sf_t4_timer_expire; 112 sctp_state_fn_t sctp_sf_t5_timer_expire; 113 sctp_state_fn_t sctp_sf_sendbeat_8_3; 114 sctp_state_fn_t sctp_sf_beat_8_3; 115 sctp_state_fn_t sctp_sf_backbeat_8_3; 116 sctp_state_fn_t sctp_sf_do_9_2_final; 117 sctp_state_fn_t sctp_sf_do_9_2_shutdown; 118 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 119 sctp_state_fn_t sctp_sf_do_ecn_cwr; 120 sctp_state_fn_t sctp_sf_do_ecne; 121 sctp_state_fn_t sctp_sf_ootb; 122 sctp_state_fn_t sctp_sf_pdiscard; 123 sctp_state_fn_t sctp_sf_violation; 124 sctp_state_fn_t sctp_sf_discard_chunk; 125 sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 126 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 127 sctp_state_fn_t sctp_sf_do_5_2_3_initack; 128 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 129 sctp_state_fn_t sctp_sf_unk_chunk; 130 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 131 sctp_state_fn_t sctp_sf_cookie_echoed_err; 132 sctp_state_fn_t sctp_sf_do_asconf; 133 sctp_state_fn_t sctp_sf_do_asconf_ack; 134 sctp_state_fn_t sctp_sf_do_reconf; 135 sctp_state_fn_t sctp_sf_do_9_2_reshutack; 136 sctp_state_fn_t sctp_sf_eat_fwd_tsn; 137 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; 138 sctp_state_fn_t sctp_sf_eat_auth; 139 140 /* Prototypes for primitive event state functions. */ 141 sctp_state_fn_t sctp_sf_do_prm_asoc; 142 sctp_state_fn_t sctp_sf_do_prm_send; 143 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; 144 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; 145 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; 146 sctp_state_fn_t sctp_sf_do_9_1_prm_abort; 147 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; 148 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; 149 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; 150 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; 151 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; 152 sctp_state_fn_t sctp_sf_error_closed; 153 sctp_state_fn_t sctp_sf_error_shutdown; 154 sctp_state_fn_t sctp_sf_ignore_primitive; 155 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; 156 sctp_state_fn_t sctp_sf_do_prm_asconf; 157 sctp_state_fn_t sctp_sf_do_prm_reconf; 158 159 /* Prototypes for other event state functions. */ 160 sctp_state_fn_t sctp_sf_do_no_pending_tsn; 161 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 162 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 163 sctp_state_fn_t sctp_sf_ignore_other; 164 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 165 166 /* Prototypes for timeout event state functions. */ 167 sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 168 sctp_state_fn_t sctp_sf_send_reconf; 169 sctp_state_fn_t sctp_sf_do_6_2_sack; 170 sctp_state_fn_t sctp_sf_autoclose_timer_expire; 171 172 /* Prototypes for utility support functions. */ 173 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); 174 const struct sctp_sm_table_entry *sctp_sm_lookup_event( 175 struct net *net, 176 enum sctp_event event_type, 177 enum sctp_state state, 178 union sctp_subtype event_subtype); 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 *asoc, 188 const struct sctp_bind_addr *bp, 189 gfp_t gfp, int vparam_len); 190 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 191 const struct sctp_chunk *chunk, 192 const gfp_t gfp, const int unkparam_len); 193 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 194 const struct sctp_chunk *chunk); 195 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 196 const struct sctp_chunk *chunk); 197 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 198 const __u32 lowest_tsn, 199 const struct sctp_chunk *chunk); 200 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 201 const struct sctp_sndrcvinfo *sinfo, 202 int len, const __u8 flags, 203 __u16 ssn, gfp_t gfp); 204 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 205 const __u32 lowest_tsn); 206 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc); 207 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 208 const struct sctp_chunk *chunk); 209 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 210 const struct sctp_chunk *chunk); 211 struct sctp_chunk *sctp_make_shutdown_complete( 212 const struct sctp_association *asoc, 213 const struct sctp_chunk *chunk); 214 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen); 215 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 216 const struct sctp_chunk *chunk, 217 const size_t hint); 218 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc, 219 const struct sctp_chunk *chunk, 220 __u32 tsn); 221 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 222 struct msghdr *msg, size_t msg_len); 223 struct sctp_chunk *sctp_make_abort_violation( 224 const struct sctp_association *asoc, 225 const struct sctp_chunk *chunk, 226 const __u8 *payload, 227 const size_t paylen); 228 struct sctp_chunk *sctp_make_violation_paramlen( 229 const struct sctp_association *asoc, 230 const struct sctp_chunk *chunk, 231 struct sctp_paramhdr *param); 232 struct sctp_chunk *sctp_make_violation_max_retrans( 233 const struct sctp_association *asoc, 234 const struct sctp_chunk *chunk); 235 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 236 const struct sctp_transport *transport); 237 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 238 const struct sctp_chunk *chunk, 239 const void *payload, 240 const size_t paylen); 241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 242 const struct sctp_chunk *chunk, 243 __be16 cause_code, const void *payload, 244 size_t paylen, size_t reserve_tail); 245 246 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 247 union sctp_addr *laddr, 248 struct sockaddr *addrs, 249 int addrcnt, __be16 flags); 250 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 251 union sctp_addr *addr); 252 bool sctp_verify_asconf(const struct sctp_association *asoc, 253 struct sctp_chunk *chunk, bool addr_param_needed, 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 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc, 264 __u16 stream_num, __be16 *stream_list, 265 bool out, bool in); 266 struct sctp_chunk *sctp_make_strreset_tsnreq( 267 const struct sctp_association *asoc); 268 struct sctp_chunk *sctp_make_strreset_addstrm( 269 const struct sctp_association *asoc, 270 __u16 out, __u16 in); 271 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 272 __u32 result, __u32 sn); 273 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 274 __u32 result, __u32 sn, 275 __u32 sender_tsn, 276 __u32 receiver_tsn); 277 bool sctp_verify_reconf(const struct sctp_association *asoc, 278 struct sctp_chunk *chunk, 279 struct sctp_paramhdr **errp); 280 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk); 281 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk); 282 283 /* Prototypes for stream-processing functions. */ 284 struct sctp_chunk *sctp_process_strreset_outreq( 285 struct sctp_association *asoc, 286 union sctp_params param, 287 struct sctp_ulpevent **evp); 288 struct sctp_chunk *sctp_process_strreset_inreq( 289 struct sctp_association *asoc, 290 union sctp_params param, 291 struct sctp_ulpevent **evp); 292 struct sctp_chunk *sctp_process_strreset_tsnreq( 293 struct sctp_association *asoc, 294 union sctp_params param, 295 struct sctp_ulpevent **evp); 296 struct sctp_chunk *sctp_process_strreset_addstrm_out( 297 struct sctp_association *asoc, 298 union sctp_params param, 299 struct sctp_ulpevent **evp); 300 struct sctp_chunk *sctp_process_strreset_addstrm_in( 301 struct sctp_association *asoc, 302 union sctp_params param, 303 struct sctp_ulpevent **evp); 304 struct sctp_chunk *sctp_process_strreset_resp( 305 struct sctp_association *asoc, 306 union sctp_params param, 307 struct sctp_ulpevent **evp); 308 309 /* Prototypes for statetable processing. */ 310 311 int sctp_do_sm(struct net *net, enum sctp_event event_type, 312 union sctp_subtype subtype, enum sctp_state state, 313 struct sctp_endpoint *ep, struct sctp_association *asoc, 314 void *event_arg, gfp_t gfp); 315 316 /* 2nd level prototypes */ 317 void sctp_generate_t3_rtx_event(struct timer_list *t); 318 void sctp_generate_heartbeat_event(struct timer_list *t); 319 void sctp_generate_reconf_event(struct timer_list *t); 320 void sctp_generate_proto_unreach_event(struct timer_list *t); 321 322 void sctp_ootb_pkt_free(struct sctp_packet *packet); 323 324 struct sctp_association *sctp_unpack_cookie( 325 const struct sctp_endpoint *ep, 326 const struct sctp_association *asoc, 327 struct sctp_chunk *chunk, 328 gfp_t gfp, int *err, 329 struct sctp_chunk **err_chk_p); 330 331 /* 3rd level prototypes */ 332 __u32 sctp_generate_tag(const struct sctp_endpoint *ep); 333 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep); 334 335 /* Extern declarations for major data structures. */ 336 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 337 338 339 /* Get the size of a DATA chunk payload. */ 340 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 341 { 342 __u16 size; 343 344 size = ntohs(chunk->chunk_hdr->length); 345 size -= sizeof(struct sctp_data_chunk); 346 347 return size; 348 } 349 350 /* Compare two TSNs */ 351 #define TSN_lt(a,b) \ 352 (typecheck(__u32, a) && \ 353 typecheck(__u32, b) && \ 354 ((__s32)((a) - (b)) < 0)) 355 356 #define TSN_lte(a,b) \ 357 (typecheck(__u32, a) && \ 358 typecheck(__u32, b) && \ 359 ((__s32)((a) - (b)) <= 0)) 360 361 /* Compare two SSNs */ 362 #define SSN_lt(a,b) \ 363 (typecheck(__u16, a) && \ 364 typecheck(__u16, b) && \ 365 ((__s16)((a) - (b)) < 0)) 366 367 /* ADDIP 3.1.1 */ 368 #define ADDIP_SERIAL_gte(a,b) \ 369 (typecheck(__u32, a) && \ 370 typecheck(__u32, b) && \ 371 ((__s32)((b) - (a)) <= 0)) 372 373 /* Check VTAG of the packet matches the sender's own tag. */ 374 static inline int 375 sctp_vtag_verify(const struct sctp_chunk *chunk, 376 const struct sctp_association *asoc) 377 { 378 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 379 * MUST ensure that the value in the Verification Tag field of 380 * the received SCTP packet matches its own Tag. If the received 381 * Verification Tag value does not match the receiver's own 382 * tag value, the receiver shall silently discard the packet... 383 */ 384 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 385 return 1; 386 387 return 0; 388 } 389 390 /* Check VTAG of the packet matches the sender's own tag and the T bit is 391 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 392 */ 393 static inline int 394 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 395 const struct sctp_association *asoc) 396 { 397 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 398 * 399 * B) The receiver of a ABORT MUST accept the packet 400 * if the Verification Tag field of the packet matches its own tag 401 * and the T bit is not set 402 * OR 403 * it is set to its peer's tag and the T bit is set in the Chunk 404 * Flags. 405 * Otherwise, the receiver MUST silently discard the packet 406 * and take no further action. 407 * 408 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 409 * if the Verification Tag field of the packet matches its own tag 410 * and the T bit is not set 411 * OR 412 * it is set to its peer's tag and the T bit is set in the Chunk 413 * Flags. 414 * Otherwise, the receiver MUST silently discard the packet 415 * and take no further action. An endpoint MUST ignore the 416 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 417 */ 418 if ((!sctp_test_T_bit(chunk) && 419 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 420 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 421 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 422 return 1; 423 } 424 425 return 0; 426 } 427 428 #endif /* __sctp_sm_h__ */ 429