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_reconf; 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 sctp_state_fn_t sctp_sf_do_prm_reconf; 162 163 /* Prototypes for other event state functions. */ 164 sctp_state_fn_t sctp_sf_do_no_pending_tsn; 165 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 166 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 167 sctp_state_fn_t sctp_sf_ignore_other; 168 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 169 170 /* Prototypes for timeout event state functions. */ 171 sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 172 sctp_state_fn_t sctp_sf_send_reconf; 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(struct net *, 179 sctp_event_t, 180 sctp_state_t, 181 sctp_subtype_t); 182 int sctp_chunk_iif(const struct sctp_chunk *); 183 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, 184 struct sctp_chunk *, 185 gfp_t gfp); 186 __u32 sctp_generate_verification_tag(void); 187 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); 188 189 /* Prototypes for chunk-building functions. */ 190 struct sctp_chunk *sctp_make_init(const struct sctp_association *, 191 const struct sctp_bind_addr *, 192 gfp_t gfp, int vparam_len); 193 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, 194 const struct sctp_chunk *, 195 const gfp_t gfp, 196 const int unkparam_len); 197 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, 198 const struct sctp_chunk *); 199 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, 200 const struct sctp_chunk *); 201 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, 202 const __u32 lowest_tsn, 203 const struct sctp_chunk *); 204 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, 205 const struct sctp_sndrcvinfo *sinfo, 206 int len, const __u8 flags, 207 __u16 ssn, gfp_t gfp); 208 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, 209 const __u32); 210 struct sctp_chunk *sctp_make_sack(const struct sctp_association *); 211 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 212 const struct sctp_chunk *chunk); 213 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 214 const struct sctp_chunk *); 215 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, 216 const struct sctp_chunk *); 217 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); 218 struct sctp_chunk *sctp_make_abort(const struct sctp_association *, 219 const struct sctp_chunk *, 220 const size_t hint); 221 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, 222 const struct sctp_chunk *, 223 __u32 tsn); 224 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, 225 struct msghdr *, size_t msg_len); 226 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, 227 const struct sctp_chunk *, 228 const __u8 *, 229 const size_t ); 230 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, 231 const struct sctp_chunk *, 232 struct sctp_paramhdr *); 233 struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, 234 const struct sctp_chunk *); 235 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, 236 const struct sctp_transport *); 237 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, 238 const struct sctp_chunk *, 239 const void *payload, 240 const size_t paylen); 241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, 242 const struct sctp_chunk *chunk, 243 __be16 cause_code, 244 const void *payload, 245 size_t paylen, 246 size_t reserve_tail); 247 248 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 249 union sctp_addr *, 250 struct sockaddr *, 251 int, __be16); 252 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 253 union sctp_addr *addr); 254 bool sctp_verify_asconf(const struct sctp_association *asoc, 255 struct sctp_chunk *chunk, bool addr_param_needed, 256 struct sctp_paramhdr **errp); 257 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 258 struct sctp_chunk *asconf); 259 int sctp_process_asconf_ack(struct sctp_association *asoc, 260 struct sctp_chunk *asconf_ack); 261 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 262 __u32 new_cum_tsn, size_t nstreams, 263 struct sctp_fwdtsn_skip *skiplist); 264 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); 265 struct sctp_chunk *sctp_make_strreset_req( 266 const struct sctp_association *asoc, 267 __u16 stream_num, __u16 *stream_list, 268 bool out, bool in); 269 struct sctp_chunk *sctp_make_strreset_tsnreq( 270 const struct sctp_association *asoc); 271 struct sctp_chunk *sctp_make_strreset_addstrm( 272 const struct sctp_association *asoc, 273 __u16 out, __u16 in); 274 struct sctp_chunk *sctp_make_strreset_resp( 275 const struct sctp_association *asoc, 276 __u32 result, __u32 sn); 277 struct sctp_chunk *sctp_make_strreset_tsnresp( 278 struct sctp_association *asoc, 279 __u32 result, __u32 sn, 280 __u32 sender_tsn, __u32 receiver_tsn); 281 bool sctp_verify_reconf(const struct sctp_association *asoc, 282 struct sctp_chunk *chunk, 283 struct sctp_paramhdr **errp); 284 void sctp_chunk_assign_tsn(struct sctp_chunk *); 285 void sctp_chunk_assign_ssn(struct sctp_chunk *); 286 287 /* Prototypes for stream-processing functions. */ 288 struct sctp_chunk *sctp_process_strreset_outreq( 289 struct sctp_association *asoc, 290 union sctp_params param, 291 struct sctp_ulpevent **evp); 292 struct sctp_chunk *sctp_process_strreset_inreq( 293 struct sctp_association *asoc, 294 union sctp_params param, 295 struct sctp_ulpevent **evp); 296 struct sctp_chunk *sctp_process_strreset_tsnreq( 297 struct sctp_association *asoc, 298 union sctp_params param, 299 struct sctp_ulpevent **evp); 300 struct sctp_chunk *sctp_process_strreset_addstrm_out( 301 struct sctp_association *asoc, 302 union sctp_params param, 303 struct sctp_ulpevent **evp); 304 struct sctp_chunk *sctp_process_strreset_addstrm_in( 305 struct sctp_association *asoc, 306 union sctp_params param, 307 struct sctp_ulpevent **evp); 308 struct sctp_chunk *sctp_process_strreset_resp( 309 struct sctp_association *asoc, 310 union sctp_params param, 311 struct sctp_ulpevent **evp); 312 313 /* Prototypes for statetable processing. */ 314 315 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 316 sctp_state_t state, 317 struct sctp_endpoint *, 318 struct sctp_association *asoc, 319 void *event_arg, 320 gfp_t gfp); 321 322 /* 2nd level prototypes */ 323 void sctp_generate_t3_rtx_event(unsigned long peer); 324 void sctp_generate_heartbeat_event(unsigned long peer); 325 void sctp_generate_reconf_event(unsigned long peer); 326 void sctp_generate_proto_unreach_event(unsigned long peer); 327 328 void sctp_ootb_pkt_free(struct sctp_packet *packet); 329 330 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *ep, 331 const struct sctp_association *asoc, 332 struct sctp_chunk *chunk, 333 gfp_t gfp, int *err, 334 struct sctp_chunk **err_chk_p); 335 336 /* 3rd level prototypes */ 337 __u32 sctp_generate_tag(const struct sctp_endpoint *ep); 338 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep); 339 340 /* Extern declarations for major data structures. */ 341 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 342 343 344 /* Get the size of a DATA chunk payload. */ 345 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 346 { 347 __u16 size; 348 349 size = ntohs(chunk->chunk_hdr->length); 350 size -= sizeof(struct sctp_data_chunk); 351 352 return size; 353 } 354 355 /* Compare two TSNs */ 356 #define TSN_lt(a,b) \ 357 (typecheck(__u32, a) && \ 358 typecheck(__u32, b) && \ 359 ((__s32)((a) - (b)) < 0)) 360 361 #define TSN_lte(a,b) \ 362 (typecheck(__u32, a) && \ 363 typecheck(__u32, b) && \ 364 ((__s32)((a) - (b)) <= 0)) 365 366 /* Compare two SSNs */ 367 #define SSN_lt(a,b) \ 368 (typecheck(__u16, a) && \ 369 typecheck(__u16, b) && \ 370 ((__s16)((a) - (b)) < 0)) 371 372 /* ADDIP 3.1.1 */ 373 #define ADDIP_SERIAL_gte(a,b) \ 374 (typecheck(__u32, a) && \ 375 typecheck(__u32, b) && \ 376 ((__s32)((b) - (a)) <= 0)) 377 378 /* Check VTAG of the packet matches the sender's own tag. */ 379 static inline int 380 sctp_vtag_verify(const struct sctp_chunk *chunk, 381 const struct sctp_association *asoc) 382 { 383 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 384 * MUST ensure that the value in the Verification Tag field of 385 * the received SCTP packet matches its own Tag. If the received 386 * Verification Tag value does not match the receiver's own 387 * tag value, the receiver shall silently discard the packet... 388 */ 389 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 390 return 1; 391 392 return 0; 393 } 394 395 /* Check VTAG of the packet matches the sender's own tag and the T bit is 396 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 397 */ 398 static inline int 399 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 400 const struct sctp_association *asoc) 401 { 402 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 403 * 404 * B) The receiver of a ABORT MUST accept the packet 405 * if the Verification Tag field of the packet matches its own tag 406 * and the T bit is not set 407 * OR 408 * it is set to its peer's tag and the T bit is set in the Chunk 409 * Flags. 410 * Otherwise, the receiver MUST silently discard the packet 411 * and take no further action. 412 * 413 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 414 * if the Verification Tag field of the packet matches its own tag 415 * and the T bit is not set 416 * OR 417 * it is set to its peer's tag and the T bit is set in the Chunk 418 * Flags. 419 * Otherwise, the receiver MUST silently discard the packet 420 * and take no further action. An endpoint MUST ignore the 421 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 422 */ 423 if ((!sctp_test_T_bit(chunk) && 424 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 425 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 426 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 427 return 1; 428 } 429 430 return 0; 431 } 432 433 #endif /* __sctp_sm_h__ */ 434