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 */ 56typedef 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 68typedef struct { 69 int name; 70 int action; 71} sctp_sm_command_t; 72 73typedef 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 *); 79typedef void (sctp_timer_event_t) (unsigned long); 80typedef 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. */ 90sctp_state_fn_t sctp_sf_not_impl; 91sctp_state_fn_t sctp_sf_bug; 92 93/* Prototypes for gener timer state functions. */ 94sctp_state_fn_t sctp_sf_timer_ignore; 95 96/* Prototypes for chunk state functions. */ 97sctp_state_fn_t sctp_sf_do_9_1_abort; 98sctp_state_fn_t sctp_sf_cookie_wait_abort; 99sctp_state_fn_t sctp_sf_cookie_echoed_abort; 100sctp_state_fn_t sctp_sf_shutdown_pending_abort; 101sctp_state_fn_t sctp_sf_shutdown_sent_abort; 102sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort; 103sctp_state_fn_t sctp_sf_do_5_1B_init; 104sctp_state_fn_t sctp_sf_do_5_1C_ack; 105sctp_state_fn_t sctp_sf_do_5_1D_ce; 106sctp_state_fn_t sctp_sf_do_5_1E_ca; 107sctp_state_fn_t sctp_sf_do_4_C; 108sctp_state_fn_t sctp_sf_eat_data_6_2; 109sctp_state_fn_t sctp_sf_eat_data_fast_4_4; 110sctp_state_fn_t sctp_sf_eat_sack_6_2; 111sctp_state_fn_t sctp_sf_operr_notify; 112sctp_state_fn_t sctp_sf_t1_init_timer_expire; 113sctp_state_fn_t sctp_sf_t1_cookie_timer_expire; 114sctp_state_fn_t sctp_sf_t2_timer_expire; 115sctp_state_fn_t sctp_sf_t4_timer_expire; 116sctp_state_fn_t sctp_sf_t5_timer_expire; 117sctp_state_fn_t sctp_sf_sendbeat_8_3; 118sctp_state_fn_t sctp_sf_beat_8_3; 119sctp_state_fn_t sctp_sf_backbeat_8_3; 120sctp_state_fn_t sctp_sf_do_9_2_final; 121sctp_state_fn_t sctp_sf_do_9_2_shutdown; 122sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn; 123sctp_state_fn_t sctp_sf_do_ecn_cwr; 124sctp_state_fn_t sctp_sf_do_ecne; 125sctp_state_fn_t sctp_sf_ootb; 126sctp_state_fn_t sctp_sf_pdiscard; 127sctp_state_fn_t sctp_sf_violation; 128sctp_state_fn_t sctp_sf_discard_chunk; 129sctp_state_fn_t sctp_sf_do_5_2_1_siminit; 130sctp_state_fn_t sctp_sf_do_5_2_2_dupinit; 131sctp_state_fn_t sctp_sf_do_5_2_3_initack; 132sctp_state_fn_t sctp_sf_do_5_2_4_dupcook; 133sctp_state_fn_t sctp_sf_unk_chunk; 134sctp_state_fn_t sctp_sf_do_8_5_1_E_sa; 135sctp_state_fn_t sctp_sf_cookie_echoed_err; 136sctp_state_fn_t sctp_sf_do_asconf; 137sctp_state_fn_t sctp_sf_do_asconf_ack; 138sctp_state_fn_t sctp_sf_do_9_2_reshutack; 139sctp_state_fn_t sctp_sf_eat_fwd_tsn; 140sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast; 141sctp_state_fn_t sctp_sf_eat_auth; 142 143/* Prototypes for primitive event state functions. */ 144sctp_state_fn_t sctp_sf_do_prm_asoc; 145sctp_state_fn_t sctp_sf_do_prm_send; 146sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown; 147sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown; 148sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown; 149sctp_state_fn_t sctp_sf_do_9_1_prm_abort; 150sctp_state_fn_t sctp_sf_cookie_wait_prm_abort; 151sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort; 152sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort; 153sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort; 154sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort; 155sctp_state_fn_t sctp_sf_error_closed; 156sctp_state_fn_t sctp_sf_error_shutdown; 157sctp_state_fn_t sctp_sf_ignore_primitive; 158sctp_state_fn_t sctp_sf_do_prm_requestheartbeat; 159sctp_state_fn_t sctp_sf_do_prm_asconf; 160 161/* Prototypes for other event state functions. */ 162sctp_state_fn_t sctp_sf_do_no_pending_tsn; 163sctp_state_fn_t sctp_sf_do_9_2_start_shutdown; 164sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack; 165sctp_state_fn_t sctp_sf_ignore_other; 166sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort; 167 168/* Prototypes for timeout event state functions. */ 169sctp_state_fn_t sctp_sf_do_6_3_3_rtx; 170sctp_state_fn_t sctp_sf_do_6_2_sack; 171sctp_state_fn_t sctp_sf_autoclose_timer_expire; 172 173/* Prototypes for utility support functions. */ 174__u8 sctp_get_chunk_type(struct sctp_chunk *chunk); 175const sctp_sm_table_entry_t *sctp_sm_lookup_event(struct net *, 176 sctp_event_t, 177 sctp_state_t, 178 sctp_subtype_t); 179int sctp_chunk_iif(const struct sctp_chunk *); 180struct 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); 184void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag); 185 186/* Prototypes for chunk-building functions. */ 187struct sctp_chunk *sctp_make_init(const struct sctp_association *, 188 const struct sctp_bind_addr *, 189 gfp_t gfp, int vparam_len); 190struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *, 191 const struct sctp_chunk *, 192 const gfp_t gfp, 193 const int unkparam_len); 194struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *, 195 const struct sctp_chunk *); 196struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *, 197 const struct sctp_chunk *); 198struct sctp_chunk *sctp_make_cwr(const struct sctp_association *, 199 const __u32 lowest_tsn, 200 const struct sctp_chunk *); 201struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *, 202 const struct sctp_sndrcvinfo *sinfo, 203 int len, const __u8 flags, 204 __u16 ssn); 205struct sctp_chunk *sctp_make_ecne(const struct sctp_association *, 206 const __u32); 207struct sctp_chunk *sctp_make_sack(const struct sctp_association *); 208struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 209 const struct sctp_chunk *chunk); 210struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 211 const struct sctp_chunk *); 212struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *, 213 const struct sctp_chunk *); 214void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t); 215struct sctp_chunk *sctp_make_abort(const struct sctp_association *, 216 const struct sctp_chunk *, 217 const size_t hint); 218struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *, 219 const struct sctp_chunk *, 220 __u32 tsn); 221struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *, 222 struct msghdr *, size_t msg_len); 223struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *, 224 const struct sctp_chunk *, 225 const __u8 *, 226 const size_t ); 227struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *, 228 const struct sctp_chunk *, 229 struct sctp_paramhdr *); 230struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *, 231 const struct sctp_chunk *); 232struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *, 233 const struct sctp_transport *); 234struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *, 235 const struct sctp_chunk *, 236 const void *payload, 237 const size_t paylen); 238struct sctp_chunk *sctp_make_op_error(const struct sctp_association *, 239 const struct sctp_chunk *chunk, 240 __be16 cause_code, 241 const void *payload, 242 size_t paylen, 243 size_t reserve_tail); 244 245struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *, 246 union sctp_addr *, 247 struct sockaddr *, 248 int, __be16); 249struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 250 union sctp_addr *addr); 251bool sctp_verify_asconf(const struct sctp_association *asoc, 252 struct sctp_chunk *chunk, bool addr_param_needed, 253 struct sctp_paramhdr **errp); 254struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 255 struct sctp_chunk *asconf); 256int sctp_process_asconf_ack(struct sctp_association *asoc, 257 struct sctp_chunk *asconf_ack); 258struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 259 __u32 new_cum_tsn, size_t nstreams, 260 struct sctp_fwdtsn_skip *skiplist); 261struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc); 262 263void sctp_chunk_assign_tsn(struct sctp_chunk *); 264void sctp_chunk_assign_ssn(struct sctp_chunk *); 265 266/* Prototypes for statetable processing. */ 267 268int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 269 sctp_state_t state, 270 struct sctp_endpoint *, 271 struct sctp_association *asoc, 272 void *event_arg, 273 gfp_t gfp); 274 275/* 2nd level prototypes */ 276void sctp_generate_t3_rtx_event(unsigned long peer); 277void sctp_generate_heartbeat_event(unsigned long peer); 278void sctp_generate_proto_unreach_event(unsigned long peer); 279 280void sctp_ootb_pkt_free(struct sctp_packet *); 281 282struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *, 283 const struct sctp_association *, 284 struct sctp_chunk *, 285 gfp_t gfp, int *err, 286 struct sctp_chunk **err_chk_p); 287int sctp_addip_addr_config(struct sctp_association *, sctp_param_t, 288 struct sockaddr_storage*, int); 289 290/* 3rd level prototypes */ 291__u32 sctp_generate_tag(const struct sctp_endpoint *); 292__u32 sctp_generate_tsn(const struct sctp_endpoint *); 293 294/* Extern declarations for major data structures. */ 295extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES]; 296 297 298/* Get the size of a DATA chunk payload. */ 299static inline __u16 sctp_data_size(struct sctp_chunk *chunk) 300{ 301 __u16 size; 302 303 size = ntohs(chunk->chunk_hdr->length); 304 size -= sizeof(sctp_data_chunk_t); 305 306 return size; 307} 308 309/* Compare two TSNs */ 310 311/* RFC 1982 - Serial Number Arithmetic 312 * 313 * 2. Comparison 314 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2, 315 * in all other cases, s1 is not equal to s2. 316 * 317 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2, 318 * and 319 * 320 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or 321 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1)) 322 * 323 * s1 is said to be greater than s2 if, and only if, s1 is not equal to 324 * s2, and 325 * 326 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or 327 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1)) 328 */ 329 330/* 331 * RFC 2960 332 * 1.6 Serial Number Arithmetic 333 * 334 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial 335 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32. 336 */ 337 338enum { 339 TSN_SIGN_BIT = (1<<31) 340}; 341 342static inline int TSN_lt(__u32 s, __u32 t) 343{ 344 return ((s) - (t)) & TSN_SIGN_BIT; 345} 346 347static inline int TSN_lte(__u32 s, __u32 t) 348{ 349 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 350} 351 352/* Compare two SSNs */ 353 354/* 355 * RFC 2960 356 * 1.6 Serial Number Arithmetic 357 * 358 * Comparisons and arithmetic on Stream Sequence Numbers in this document 359 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where 360 * SERIAL_BITS = 16. 361 */ 362enum { 363 SSN_SIGN_BIT = (1<<15) 364}; 365 366static inline int SSN_lt(__u16 s, __u16 t) 367{ 368 return ((s) - (t)) & SSN_SIGN_BIT; 369} 370 371static inline int SSN_lte(__u16 s, __u16 t) 372{ 373 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT); 374} 375 376/* 377 * ADDIP 3.1.1 378 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial 379 * Numbers wrap back to 0 after reaching 4294967295. 380 */ 381enum { 382 ADDIP_SERIAL_SIGN_BIT = (1<<31) 383}; 384 385static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t) 386{ 387 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT); 388} 389 390/* Check VTAG of the packet matches the sender's own tag. */ 391static inline int 392sctp_vtag_verify(const struct sctp_chunk *chunk, 393 const struct sctp_association *asoc) 394{ 395 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint 396 * MUST ensure that the value in the Verification Tag field of 397 * the received SCTP packet matches its own Tag. If the received 398 * Verification Tag value does not match the receiver's own 399 * tag value, the receiver shall silently discard the packet... 400 */ 401 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag) 402 return 1; 403 404 return 0; 405} 406 407/* Check VTAG of the packet matches the sender's own tag and the T bit is 408 * not set, OR its peer's tag and the T bit is set in the Chunk Flags. 409 */ 410static inline int 411sctp_vtag_verify_either(const struct sctp_chunk *chunk, 412 const struct sctp_association *asoc) 413{ 414 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41 415 * 416 * B) The receiver of a ABORT MUST accept the packet 417 * if the Verification Tag field of the packet matches its own tag 418 * and the T bit is not set 419 * OR 420 * it is set to its peer's tag and the T bit is set in the Chunk 421 * Flags. 422 * Otherwise, the receiver MUST silently discard the packet 423 * and take no further action. 424 * 425 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet 426 * if the Verification Tag field of the packet matches its own tag 427 * and the T bit is not set 428 * OR 429 * it is set to its peer's tag and the T bit is set in the Chunk 430 * Flags. 431 * Otherwise, the receiver MUST silently discard the packet 432 * and take no further action. An endpoint MUST ignore the 433 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. 434 */ 435 if ((!sctp_test_T_bit(chunk) && 436 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) || 437 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag && 438 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) { 439 return 1; 440 } 441 442 return 0; 443} 444 445#endif /* __sctp_sm_h__ */ 446