1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * These are definitions needed by the state machine. 11 * 12 * Please send any bug reports or fixes you make to the 13 * email addresses: 14 * lksctp developers <linux-sctp@vger.kernel.org> 15 * 16 * Written or modified by: 17 * La Monte H.P. Yarroll <piggy@acm.org> 18 * Karl Knutson <karl@athena.chicago.il.us> 19 * Xingang Guo <xingang.guo@intel.com> 20 * Jon Grimm <jgrimm@us.ibm.com> 21 * Dajiang Zhang <dajiang.zhang@nokia.com> 22 * Sridhar Samudrala <sri@us.ibm.com> 23 * Daisy Chang <daisyc@us.ibm.com> 24 * Ardelle Fan <ardelle.fan@intel.com> 25 * Kevin Gao <kevin.gao@intel.com> 26 */ 27 28 #include <linux/types.h> 29 #include <linux/compiler.h> 30 #include <linux/slab.h> 31 #include <linux/in.h> 32 #include <net/sctp/command.h> 33 #include <net/sctp/sctp.h> 34 35 #ifndef __sctp_sm_h__ 36 #define __sctp_sm_h__ 37 38 /* 39 * Possible values for the disposition are: 40 */ 41 enum sctp_disposition { 42 SCTP_DISPOSITION_DISCARD, /* No further processing. */ 43 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */ 44 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */ 45 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */ 46 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */ 47 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */ 48 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */ 49 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */ 50 SCTP_DISPOSITION_BUG, /* This is a bug. */ 51 }; 52 53 typedef enum sctp_disposition (sctp_state_fn_t) ( 54 struct net *net, 55 const struct sctp_endpoint *ep, 56 const struct sctp_association *asoc, 57 const union sctp_subtype type, 58 void *arg, 59 struct sctp_cmd_seq *commands); 60 typedef void (sctp_timer_event_t) (struct timer_list *); 61 struct sctp_sm_table_entry { 62 sctp_state_fn_t *fn; 63 const char *name; 64 }; 65 66 /* A naming convention of "sctp_sf_xxx" applies to all the state functions 67 * currently in use. 68 */ 69 70 /* Prototypes for generic state functions. */ 71 sctp_state_fn_t sctp_sf_not_impl; 72 sctp_state_fn_t sctp_sf_bug; 73 74 /* Prototypes for gener timer state functions. */ 75 sctp_state_fn_t sctp_sf_timer_ignore; 76 77 /* Prototypes for chunk state functions. */ 78 sctp_state_fn_t sctp_sf_do_9_1_abort; 79 sctp_state_fn_t sctp_sf_cookie_wait_abort; 80 sctp_state_fn_t sctp_sf_cookie_echoed_abort; 81 sctp_state_fn_t sctp_sf_shutdown_pending_abort; 82 sctp_state_fn_t sctp_sf_shutdown_sent_abort; 83 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; 84 sctp_state_fn_t sctp_sf_do_5_1B_init; 85 sctp_state_fn_t sctp_sf_do_5_1C_ack; 86 sctp_state_fn_t sctp_sf_do_5_1D_ce; 87 sctp_state_fn_t sctp_sf_do_5_1E_ca; 88 sctp_state_fn_t sctp_sf_do_4_C; 89 sctp_state_fn_t sctp_sf_eat_data_6_2; 90 sctp_state_fn_t sctp_sf_eat_data_fast_4_4; 91 sctp_state_fn_t sctp_sf_eat_sack_6_2; 92 sctp_state_fn_t sctp_sf_operr_notify; 93 sctp_state_fn_t sctp_sf_t1_init_timer_expire; 94 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 95 sctp_state_fn_t sctp_sf_t2_timer_expire; 96 sctp_state_fn_t sctp_sf_t4_timer_expire; 97 sctp_state_fn_t sctp_sf_t5_timer_expire; 98 sctp_state_fn_t sctp_sf_sendbeat_8_3; 99 sctp_state_fn_t sctp_sf_beat_8_3; 100 sctp_state_fn_t sctp_sf_backbeat_8_3; 101 sctp_state_fn_t sctp_sf_do_9_2_final; 102 sctp_state_fn_t sctp_sf_do_9_2_shutdown; 103 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 104 sctp_state_fn_t sctp_sf_do_ecn_cwr; 105 sctp_state_fn_t sctp_sf_do_ecne; 106 sctp_state_fn_t sctp_sf_ootb; 107 sctp_state_fn_t sctp_sf_pdiscard; 108 sctp_state_fn_t sctp_sf_violation; 109 sctp_state_fn_t sctp_sf_discard_chunk; 110 sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 111 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 112 sctp_state_fn_t sctp_sf_do_5_2_3_initack; 113 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 114 sctp_state_fn_t sctp_sf_unk_chunk; 115 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 116 sctp_state_fn_t sctp_sf_cookie_echoed_err; 117 sctp_state_fn_t sctp_sf_do_asconf; 118 sctp_state_fn_t sctp_sf_do_asconf_ack; 119 sctp_state_fn_t sctp_sf_do_reconf; 120 sctp_state_fn_t sctp_sf_do_9_2_reshutack; 121 sctp_state_fn_t sctp_sf_eat_fwd_tsn; 122 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; 123 sctp_state_fn_t sctp_sf_eat_auth; 124 125 /* Prototypes for primitive event state functions. */ 126 sctp_state_fn_t sctp_sf_do_prm_asoc; 127 sctp_state_fn_t sctp_sf_do_prm_send; 128 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; 129 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; 130 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; 131 sctp_state_fn_t sctp_sf_do_9_1_prm_abort; 132 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; 133 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; 134 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; 135 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; 136 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; 137 sctp_state_fn_t sctp_sf_error_closed; 138 sctp_state_fn_t sctp_sf_error_shutdown; 139 sctp_state_fn_t sctp_sf_ignore_primitive; 140 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; 141 sctp_state_fn_t sctp_sf_do_prm_asconf; 142 sctp_state_fn_t sctp_sf_do_prm_reconf; 143 144 /* Prototypes for other event state functions. */ 145 sctp_state_fn_t sctp_sf_do_no_pending_tsn; 146 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 147 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 148 sctp_state_fn_t sctp_sf_ignore_other; 149 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 150 151 /* Prototypes for timeout event state functions. */ 152 sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 153 sctp_state_fn_t sctp_sf_send_reconf; 154 sctp_state_fn_t sctp_sf_do_6_2_sack; 155 sctp_state_fn_t sctp_sf_autoclose_timer_expire; 156 157 /* Prototypes for utility support functions. */ 158 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk); 159 const struct sctp_sm_table_entry *sctp_sm_lookup_event( 160 struct net *net, 161 enum sctp_event_type event_type, 162 enum sctp_state state, 163 union sctp_subtype event_subtype); 164 int sctp_chunk_iif(const struct sctp_chunk *); 165 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, 166 struct sctp_chunk *, 167 gfp_t gfp); 168 __u32 sctp_generate_verification_tag(void); 169 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); 170 171 /* Prototypes for chunk-building functions. */ 172 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 173 const struct sctp_bind_addr *bp, 174 gfp_t gfp, int vparam_len); 175 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 176 const struct sctp_chunk *chunk, 177 const gfp_t gfp, const int unkparam_len); 178 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 179 const struct sctp_chunk *chunk); 180 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 181 const struct sctp_chunk *chunk); 182 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 183 const __u32 lowest_tsn, 184 const struct sctp_chunk *chunk); 185 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 186 __u8 flags, int paylen, gfp_t gfp); 187 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 188 __u32 new_cum_tsn, size_t nstreams, 189 struct sctp_ifwdtsn_skip *skiplist); 190 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 191 const struct sctp_sndrcvinfo *sinfo, 192 int len, __u8 flags, gfp_t gfp); 193 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 194 const __u32 lowest_tsn); 195 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc); 196 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 197 const struct sctp_chunk *chunk); 198 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 199 const struct sctp_chunk *chunk); 200 struct sctp_chunk *sctp_make_shutdown_complete( 201 const struct sctp_association *asoc, 202 const struct sctp_chunk *chunk); 203 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen); 204 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 205 const struct sctp_chunk *chunk, 206 const size_t hint); 207 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc, 208 const struct sctp_chunk *chunk, 209 __u32 tsn); 210 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 211 struct msghdr *msg, size_t msg_len); 212 struct sctp_chunk *sctp_make_abort_violation( 213 const struct sctp_association *asoc, 214 const struct sctp_chunk *chunk, 215 const __u8 *payload, 216 const size_t paylen); 217 struct sctp_chunk *sctp_make_violation_paramlen( 218 const struct sctp_association *asoc, 219 const struct sctp_chunk *chunk, 220 struct sctp_paramhdr *param); 221 struct sctp_chunk *sctp_make_violation_max_retrans( 222 const struct sctp_association *asoc, 223 const struct sctp_chunk *chunk); 224 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 225 const struct sctp_transport *transport); 226 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 227 const struct sctp_chunk *chunk, 228 const void *payload, 229 const size_t paylen); 230 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 231 const struct sctp_chunk *chunk, 232 __be16 cause_code, const void *payload, 233 size_t paylen, size_t reserve_tail); 234 235 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 236 union sctp_addr *laddr, 237 struct sockaddr *addrs, 238 int addrcnt, __be16 flags); 239 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 240 union sctp_addr *addr); 241 bool sctp_verify_asconf(const struct sctp_association *asoc, 242 struct sctp_chunk *chunk, bool addr_param_needed, 243 struct sctp_paramhdr **errp); 244 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 245 struct sctp_chunk *asconf); 246 int sctp_process_asconf_ack(struct sctp_association *asoc, 247 struct sctp_chunk *asconf_ack); 248 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 249 __u32 new_cum_tsn, size_t nstreams, 250 struct sctp_fwdtsn_skip *skiplist); 251 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 252 __u16 key_id); 253 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc, 254 __u16 stream_num, __be16 *stream_list, 255 bool out, bool in); 256 struct sctp_chunk *sctp_make_strreset_tsnreq( 257 const struct sctp_association *asoc); 258 struct sctp_chunk *sctp_make_strreset_addstrm( 259 const struct sctp_association *asoc, 260 __u16 out, __u16 in); 261 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 262 __u32 result, __u32 sn); 263 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 264 __u32 result, __u32 sn, 265 __u32 sender_tsn, 266 __u32 receiver_tsn); 267 bool sctp_verify_reconf(const struct sctp_association *asoc, 268 struct sctp_chunk *chunk, 269 struct sctp_paramhdr **errp); 270 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk); 271 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk); 272 273 /* Prototypes for stream-processing functions. */ 274 struct sctp_chunk *sctp_process_strreset_outreq( 275 struct sctp_association *asoc, 276 union sctp_params param, 277 struct sctp_ulpevent **evp); 278 struct sctp_chunk *sctp_process_strreset_inreq( 279 struct sctp_association *asoc, 280 union sctp_params param, 281 struct sctp_ulpevent **evp); 282 struct sctp_chunk *sctp_process_strreset_tsnreq( 283 struct sctp_association *asoc, 284 union sctp_params param, 285 struct sctp_ulpevent **evp); 286 struct sctp_chunk *sctp_process_strreset_addstrm_out( 287 struct sctp_association *asoc, 288 union sctp_params param, 289 struct sctp_ulpevent **evp); 290 struct sctp_chunk *sctp_process_strreset_addstrm_in( 291 struct sctp_association *asoc, 292 union sctp_params param, 293 struct sctp_ulpevent **evp); 294 struct sctp_chunk *sctp_process_strreset_resp( 295 struct sctp_association *asoc, 296 union sctp_params param, 297 struct sctp_ulpevent **evp); 298 299 /* Prototypes for statetable processing. */ 300 301 int sctp_do_sm(struct net *net, enum sctp_event_type event_type, 302 union sctp_subtype subtype, enum sctp_state state, 303 struct sctp_endpoint *ep, struct sctp_association *asoc, 304 void *event_arg, gfp_t gfp); 305 306 /* 2nd level prototypes */ 307 void sctp_generate_t3_rtx_event(struct timer_list *t); 308 void sctp_generate_heartbeat_event(struct timer_list *t); 309 void sctp_generate_reconf_event(struct timer_list *t); 310 void sctp_generate_proto_unreach_event(struct timer_list *t); 311 312 void sctp_ootb_pkt_free(struct sctp_packet *packet); 313 314 struct sctp_association *sctp_unpack_cookie( 315 const struct sctp_endpoint *ep, 316 const struct sctp_association *asoc, 317 struct sctp_chunk *chunk, 318 gfp_t gfp, int *err, 319 struct sctp_chunk **err_chk_p); 320 321 /* 3rd level prototypes */ 322 __u32 sctp_generate_tag(const struct sctp_endpoint *ep); 323 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep); 324 325 /* Extern declarations for major data structures. */ 326 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 327 328 329 /* Get the size of a DATA chunk payload. */ 330 static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 331 { 332 __u16 size; 333 334 size = ntohs(chunk->chunk_hdr->length); 335 size -= sctp_datachk_len(&chunk->asoc->stream); 336 337 return size; 338 } 339 340 /* Compare two TSNs */ 341 #define TSN_lt(a,b) \ 342 (typecheck(__u32, a) && \ 343 typecheck(__u32, b) && \ 344 ((__s32)((a) - (b)) < 0)) 345 346 #define TSN_lte(a,b) \ 347 (typecheck(__u32, a) && \ 348 typecheck(__u32, b) && \ 349 ((__s32)((a) - (b)) <= 0)) 350 351 /* Compare two MIDs */ 352 #define MID_lt(a, b) \ 353 (typecheck(__u32, a) && \ 354 typecheck(__u32, b) && \ 355 ((__s32)((a) - (b)) < 0)) 356 357 /* Compare two SSNs */ 358 #define SSN_lt(a,b) \ 359 (typecheck(__u16, a) && \ 360 typecheck(__u16, b) && \ 361 ((__s16)((a) - (b)) < 0)) 362 363 /* ADDIP 3.1.1 */ 364 #define ADDIP_SERIAL_gte(a,b) \ 365 (typecheck(__u32, a) && \ 366 typecheck(__u32, b) && \ 367 ((__s32)((b) - (a)) <= 0)) 368 369 /* Check VTAG of the packet matches the sender's own tag. */ 370 static inline int 371 sctp_vtag_verify(const struct sctp_chunk *chunk, 372 const struct sctp_association *asoc) 373 { 374 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 375 * MUST ensure that the value in the Verification Tag field of 376 * the received SCTP packet matches its own Tag. If the received 377 * Verification Tag value does not match the receiver's own 378 * tag value, the receiver shall silently discard the packet... 379 */ 380 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 381 return 1; 382 383 return 0; 384 } 385 386 /* Check VTAG of the packet matches the sender's own tag and the T bit is 387 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 388 */ 389 static inline int 390 sctp_vtag_verify_either(const struct sctp_chunk *chunk, 391 const struct sctp_association *asoc) 392 { 393 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 394 * 395 * B) The receiver of a ABORT MUST accept the packet 396 * if the Verification Tag field of the packet matches its own tag 397 * and the T bit is not set 398 * OR 399 * it is set to its peer's tag and the T bit is set in the Chunk 400 * Flags. 401 * Otherwise, the receiver MUST silently discard the packet 402 * and take no further action. 403 * 404 * C) The receiver of a SHUTDOWN COMPLETE shall 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. An endpoint MUST ignore the 412 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 413 */ 414 if ((!sctp_test_T_bit(chunk) && 415 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 416 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 417 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 418 return 1; 419 } 420 421 return 0; 422 } 423 424 #endif /* __sctp_sm_h__ */ 425