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 */ 41enum 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 53typedef 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); 60typedef void (sctp_timer_event_t) (struct timer_list *); 61struct 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. */ 71sctp_state_fn_t sctp_sf_not_impl; 72sctp_state_fn_t sctp_sf_bug; 73 74/* Prototypes for gener timer state functions. */ 75sctp_state_fn_t sctp_sf_timer_ignore; 76 77/* Prototypes for chunk state functions. */ 78sctp_state_fn_t sctp_sf_do_9_1_abort; 79sctp_state_fn_t sctp_sf_cookie_wait_abort; 80sctp_state_fn_t sctp_sf_cookie_echoed_abort; 81sctp_state_fn_t sctp_sf_shutdown_pending_abort; 82sctp_state_fn_t sctp_sf_shutdown_sent_abort; 83sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; 84sctp_state_fn_t sctp_sf_do_5_1B_init; 85sctp_state_fn_t sctp_sf_do_5_1C_ack; 86sctp_state_fn_t sctp_sf_do_5_1D_ce; 87sctp_state_fn_t sctp_sf_do_5_1E_ca; 88sctp_state_fn_t sctp_sf_do_4_C; 89sctp_state_fn_t sctp_sf_eat_data_6_2; 90sctp_state_fn_t sctp_sf_eat_data_fast_4_4; 91sctp_state_fn_t sctp_sf_eat_sack_6_2; 92sctp_state_fn_t sctp_sf_operr_notify; 93sctp_state_fn_t sctp_sf_t1_init_timer_expire; 94sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 95sctp_state_fn_t sctp_sf_t2_timer_expire; 96sctp_state_fn_t sctp_sf_t4_timer_expire; 97sctp_state_fn_t sctp_sf_t5_timer_expire; 98sctp_state_fn_t sctp_sf_sendbeat_8_3; 99sctp_state_fn_t sctp_sf_beat_8_3; 100sctp_state_fn_t sctp_sf_backbeat_8_3; 101sctp_state_fn_t sctp_sf_do_9_2_final; 102sctp_state_fn_t sctp_sf_do_9_2_shutdown; 103sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 104sctp_state_fn_t sctp_sf_do_ecn_cwr; 105sctp_state_fn_t sctp_sf_do_ecne; 106sctp_state_fn_t sctp_sf_ootb; 107sctp_state_fn_t sctp_sf_pdiscard; 108sctp_state_fn_t sctp_sf_violation; 109sctp_state_fn_t sctp_sf_discard_chunk; 110sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 111sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 112sctp_state_fn_t sctp_sf_do_5_2_3_initack; 113sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 114sctp_state_fn_t sctp_sf_unk_chunk; 115sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 116sctp_state_fn_t sctp_sf_cookie_echoed_err; 117sctp_state_fn_t sctp_sf_do_asconf; 118sctp_state_fn_t sctp_sf_do_asconf_ack; 119sctp_state_fn_t sctp_sf_do_reconf; 120sctp_state_fn_t sctp_sf_do_9_2_reshutack; 121sctp_state_fn_t sctp_sf_eat_fwd_tsn; 122sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; 123sctp_state_fn_t sctp_sf_eat_auth; 124 125/* Prototypes for primitive event state functions. */ 126sctp_state_fn_t sctp_sf_do_prm_asoc; 127sctp_state_fn_t sctp_sf_do_prm_send; 128sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; 129sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; 130sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; 131sctp_state_fn_t sctp_sf_do_9_1_prm_abort; 132sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; 133sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; 134sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; 135sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; 136sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; 137sctp_state_fn_t sctp_sf_error_closed; 138sctp_state_fn_t sctp_sf_error_shutdown; 139sctp_state_fn_t sctp_sf_ignore_primitive; 140sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; 141sctp_state_fn_t sctp_sf_do_prm_asconf; 142sctp_state_fn_t sctp_sf_do_prm_reconf; 143 144/* Prototypes for other event state functions. */ 145sctp_state_fn_t sctp_sf_do_no_pending_tsn; 146sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 147sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 148sctp_state_fn_t sctp_sf_ignore_other; 149sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 150 151/* Prototypes for timeout event state functions. */ 152sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 153sctp_state_fn_t sctp_sf_send_reconf; 154sctp_state_fn_t sctp_sf_send_probe; 155sctp_state_fn_t sctp_sf_do_6_2_sack; 156sctp_state_fn_t sctp_sf_autoclose_timer_expire; 157 158/* Prototypes for utility support functions. */ 159const 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); 164int sctp_chunk_iif(const struct sctp_chunk *); 165struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *, 166 struct sctp_chunk *, 167 gfp_t gfp); 168 169/* Prototypes for chunk-building functions. */ 170struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 171 const struct sctp_bind_addr *bp, 172 gfp_t gfp, int vparam_len); 173struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 174 const struct sctp_chunk *chunk, 175 const gfp_t gfp, const int unkparam_len); 176struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 177 const struct sctp_chunk *chunk); 178struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 179 const struct sctp_chunk *chunk); 180struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 181 const __u32 lowest_tsn, 182 const struct sctp_chunk *chunk); 183struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 184 __u8 flags, int paylen, gfp_t gfp); 185struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 186 __u32 new_cum_tsn, size_t nstreams, 187 struct sctp_ifwdtsn_skip *skiplist); 188struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 189 const struct sctp_sndrcvinfo *sinfo, 190 int len, __u8 flags, gfp_t gfp); 191struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 192 const __u32 lowest_tsn); 193struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc); 194struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 195 const struct sctp_chunk *chunk); 196struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 197 const struct sctp_chunk *chunk); 198struct sctp_chunk *sctp_make_shutdown_complete( 199 const struct sctp_association *asoc, 200 const struct sctp_chunk *chunk); 201int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen); 202struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 203 const struct sctp_chunk *chunk, 204 const size_t hint); 205struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc, 206 const struct sctp_chunk *chunk, 207 __u32 tsn); 208struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 209 struct msghdr *msg, size_t msg_len); 210struct sctp_chunk *sctp_make_abort_violation( 211 const struct sctp_association *asoc, 212 const struct sctp_chunk *chunk, 213 const __u8 *payload, 214 const size_t paylen); 215struct sctp_chunk *sctp_make_violation_paramlen( 216 const struct sctp_association *asoc, 217 const struct sctp_chunk *chunk, 218 struct sctp_paramhdr *param); 219struct sctp_chunk *sctp_make_violation_max_retrans( 220 const struct sctp_association *asoc, 221 const struct sctp_chunk *chunk); 222struct sctp_chunk *sctp_make_new_encap_port( 223 const struct sctp_association *asoc, 224 const struct sctp_chunk *chunk); 225struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 226 const struct sctp_transport *transport, 227 __u32 probe_size); 228struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 229 const struct sctp_chunk *chunk, 230 const void *payload, 231 const size_t paylen); 232struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len); 233struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 234 const struct sctp_chunk *chunk, 235 __be16 cause_code, const void *payload, 236 size_t paylen, size_t reserve_tail); 237 238struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 239 union sctp_addr *laddr, 240 struct sockaddr *addrs, 241 int addrcnt, __be16 flags); 242struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 243 union sctp_addr *addr); 244bool sctp_verify_asconf(const struct sctp_association *asoc, 245 struct sctp_chunk *chunk, bool addr_param_needed, 246 struct sctp_paramhdr **errp); 247struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 248 struct sctp_chunk *asconf); 249int sctp_process_asconf_ack(struct sctp_association *asoc, 250 struct sctp_chunk *asconf_ack); 251struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 252 __u32 new_cum_tsn, size_t nstreams, 253 struct sctp_fwdtsn_skip *skiplist); 254struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 255 __u16 key_id); 256struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc, 257 __u16 stream_num, __be16 *stream_list, 258 bool out, bool in); 259struct sctp_chunk *sctp_make_strreset_tsnreq( 260 const struct sctp_association *asoc); 261struct sctp_chunk *sctp_make_strreset_addstrm( 262 const struct sctp_association *asoc, 263 __u16 out, __u16 in); 264struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 265 __u32 result, __u32 sn); 266struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 267 __u32 result, __u32 sn, 268 __u32 sender_tsn, 269 __u32 receiver_tsn); 270bool sctp_verify_reconf(const struct sctp_association *asoc, 271 struct sctp_chunk *chunk, 272 struct sctp_paramhdr **errp); 273void sctp_chunk_assign_tsn(struct sctp_chunk *chunk); 274void sctp_chunk_assign_ssn(struct sctp_chunk *chunk); 275 276/* Prototypes for stream-processing functions. */ 277struct sctp_chunk *sctp_process_strreset_outreq( 278 struct sctp_association *asoc, 279 union sctp_params param, 280 struct sctp_ulpevent **evp); 281struct sctp_chunk *sctp_process_strreset_inreq( 282 struct sctp_association *asoc, 283 union sctp_params param, 284 struct sctp_ulpevent **evp); 285struct sctp_chunk *sctp_process_strreset_tsnreq( 286 struct sctp_association *asoc, 287 union sctp_params param, 288 struct sctp_ulpevent **evp); 289struct sctp_chunk *sctp_process_strreset_addstrm_out( 290 struct sctp_association *asoc, 291 union sctp_params param, 292 struct sctp_ulpevent **evp); 293struct sctp_chunk *sctp_process_strreset_addstrm_in( 294 struct sctp_association *asoc, 295 union sctp_params param, 296 struct sctp_ulpevent **evp); 297struct sctp_chunk *sctp_process_strreset_resp( 298 struct sctp_association *asoc, 299 union sctp_params param, 300 struct sctp_ulpevent **evp); 301 302/* Prototypes for statetable processing. */ 303 304int sctp_do_sm(struct net *net, enum sctp_event_type event_type, 305 union sctp_subtype subtype, enum sctp_state state, 306 struct sctp_endpoint *ep, struct sctp_association *asoc, 307 void *event_arg, gfp_t gfp); 308 309/* 2nd level prototypes */ 310void sctp_generate_t3_rtx_event(struct timer_list *t); 311void sctp_generate_heartbeat_event(struct timer_list *t); 312void sctp_generate_reconf_event(struct timer_list *t); 313void sctp_generate_probe_event(struct timer_list *t); 314void sctp_generate_proto_unreach_event(struct timer_list *t); 315 316void sctp_ootb_pkt_free(struct sctp_packet *packet); 317 318struct sctp_association *sctp_unpack_cookie( 319 const struct sctp_endpoint *ep, 320 const struct sctp_association *asoc, 321 struct sctp_chunk *chunk, 322 gfp_t gfp, int *err, 323 struct sctp_chunk **err_chk_p); 324 325/* 3rd level prototypes */ 326__u32 sctp_generate_tag(const struct sctp_endpoint *ep); 327__u32 sctp_generate_tsn(const struct sctp_endpoint *ep); 328 329/* Extern declarations for major data structures. */ 330extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 331 332 333/* Get the size of a DATA chunk payload. */ 334static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 335{ 336 __u16 size; 337 338 size = ntohs(chunk->chunk_hdr->length); 339 size -= sctp_datachk_len(&chunk->asoc->stream); 340 341 return size; 342} 343 344/* Compare two TSNs */ 345#define TSN_lt(a,b) \ 346 (typecheck(__u32, a) && \ 347 typecheck(__u32, b) && \ 348 ((__s32)((a) - (b)) < 0)) 349 350#define TSN_lte(a,b) \ 351 (typecheck(__u32, a) && \ 352 typecheck(__u32, b) && \ 353 ((__s32)((a) - (b)) <= 0)) 354 355/* Compare two MIDs */ 356#define MID_lt(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. */ 374static inline int 375sctp_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 0; 386 387 chunk->transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 388 return 1; 389} 390 391/* Check VTAG of the packet matches the sender's own tag and the T bit is 392 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 393 */ 394static inline int 395sctp_vtag_verify_either(const struct sctp_chunk *chunk, 396 const struct sctp_association *asoc) 397{ 398 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 399 * 400 * B) The receiver of a ABORT MUST accept the packet 401 * if the Verification Tag field of the packet matches its own tag 402 * and the T bit is not set 403 * OR 404 * it is set to its peer's tag and the T bit is set in the Chunk 405 * Flags. 406 * Otherwise, the receiver MUST silently discard the packet 407 * and take no further action. 408 * 409 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 410 * if the Verification Tag field of the packet matches its own tag 411 * and the T bit is not set 412 * OR 413 * it is set to its peer's tag and the T bit is set in the Chunk 414 * Flags. 415 * Otherwise, the receiver MUST silently discard the packet 416 * and take no further action. An endpoint MUST ignore the 417 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 418 */ 419 if ((!sctp_test_T_bit(chunk) && 420 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 421 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 422 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 423 return 1; 424 } 425 426 return 0; 427} 428 429#endif /* __sctp_sm_h__ */ 430