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 * Please send any bug reports or fixes you make to the 11 * email address(es): 12 * lksctp developers <linux-sctp@vger.kernel.org> 13 * 14 * Written or modified by: 15 * La Monte H.P. Yarroll <piggy@acm.org> 16 * Karl Knutson <karl@athena.chicago.il.us> 17 * Randall Stewart <randall@stewart.chicago.il.us> 18 * Ken Morneau <kmorneau@cisco.com> 19 * Qiaobing Xie <qxie1@motorola.com> 20 * Xingang Guo <xingang.guo@intel.com> 21 * Sridhar Samudrala <samudrala@us.ibm.com> 22 * Daisy Chang <daisyc@us.ibm.com> 23 */ 24 25 #ifndef __sctp_constants_h__ 26 #define __sctp_constants_h__ 27 28 #include <linux/sctp.h> 29 #include <linux/ipv6.h> /* For ipv6hdr. */ 30 #include <net/tcp_states.h> /* For TCP states used in enum sctp_sock_state */ 31 32 /* Value used for stream negotiation. */ 33 enum { SCTP_MAX_STREAM = 0xffff }; 34 enum { SCTP_DEFAULT_OUTSTREAMS = 10 }; 35 enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM }; 36 37 /* Since CIDs are sparse, we need all four of the following 38 * symbols. CIDs are dense through SCTP_CID_BASE_MAX. 39 */ 40 #define SCTP_CID_BASE_MAX SCTP_CID_SHUTDOWN_COMPLETE 41 42 #define SCTP_NUM_BASE_CHUNK_TYPES (SCTP_CID_BASE_MAX + 1) 43 44 #define SCTP_NUM_ADDIP_CHUNK_TYPES 2 45 46 #define SCTP_NUM_PRSCTP_CHUNK_TYPES 1 47 48 #define SCTP_NUM_RECONF_CHUNK_TYPES 1 49 50 #define SCTP_NUM_AUTH_CHUNK_TYPES 1 51 52 #define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNK_TYPES + \ 53 SCTP_NUM_ADDIP_CHUNK_TYPES +\ 54 SCTP_NUM_PRSCTP_CHUNK_TYPES +\ 55 SCTP_NUM_RECONF_CHUNK_TYPES +\ 56 SCTP_NUM_AUTH_CHUNK_TYPES) 57 58 /* These are the different flavours of event. */ 59 enum sctp_event_type { 60 SCTP_EVENT_T_CHUNK = 1, 61 SCTP_EVENT_T_TIMEOUT, 62 SCTP_EVENT_T_OTHER, 63 SCTP_EVENT_T_PRIMITIVE 64 }; 65 66 /* As a convenience for the state machine, we append SCTP_EVENT_* and 67 * SCTP_ULP_* to the list of possible chunks. 68 */ 69 70 enum sctp_event_timeout { 71 SCTP_EVENT_TIMEOUT_NONE = 0, 72 SCTP_EVENT_TIMEOUT_T1_COOKIE, 73 SCTP_EVENT_TIMEOUT_T1_INIT, 74 SCTP_EVENT_TIMEOUT_T2_SHUTDOWN, 75 SCTP_EVENT_TIMEOUT_T3_RTX, 76 SCTP_EVENT_TIMEOUT_T4_RTO, 77 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD, 78 SCTP_EVENT_TIMEOUT_HEARTBEAT, 79 SCTP_EVENT_TIMEOUT_RECONF, 80 SCTP_EVENT_TIMEOUT_SACK, 81 SCTP_EVENT_TIMEOUT_AUTOCLOSE, 82 }; 83 84 #define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE 85 #define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1) 86 87 enum sctp_event_other { 88 SCTP_EVENT_NO_PENDING_TSN = 0, 89 SCTP_EVENT_ICMP_PROTO_UNREACH, 90 }; 91 92 #define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH 93 #define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1) 94 95 /* These are primitive requests from the ULP. */ 96 enum sctp_event_primitive { 97 SCTP_PRIMITIVE_ASSOCIATE = 0, 98 SCTP_PRIMITIVE_SHUTDOWN, 99 SCTP_PRIMITIVE_ABORT, 100 SCTP_PRIMITIVE_SEND, 101 SCTP_PRIMITIVE_REQUESTHEARTBEAT, 102 SCTP_PRIMITIVE_ASCONF, 103 SCTP_PRIMITIVE_RECONF, 104 }; 105 106 #define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_RECONF 107 #define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1) 108 109 /* We define here a utility type for manipulating subtypes. 110 * The subtype constructors all work like this: 111 * 112 * union sctp_subtype foo = SCTP_ST_CHUNK(SCTP_CID_INIT); 113 */ 114 115 union sctp_subtype { 116 enum sctp_cid chunk; 117 enum sctp_event_timeout timeout; 118 enum sctp_event_other other; 119 enum sctp_event_primitive primitive; 120 }; 121 122 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \ 123 static inline union sctp_subtype \ 124 SCTP_ST_## _name (_type _arg) \ 125 { union sctp_subtype _retval; _retval._elt = _arg; return _retval; } 126 127 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, enum sctp_cid, chunk) 128 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, enum sctp_event_timeout, timeout) 129 SCTP_SUBTYPE_CONSTRUCTOR(OTHER, enum sctp_event_other, other) 130 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, enum sctp_event_primitive, primitive) 131 132 133 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA || \ 134 a->chunk_hdr->type == SCTP_CID_I_DATA) 135 136 /* Internal error codes */ 137 enum sctp_ierror { 138 SCTP_IERROR_NO_ERROR = 0, 139 SCTP_IERROR_BASE = 1000, 140 SCTP_IERROR_NO_COOKIE, 141 SCTP_IERROR_BAD_SIG, 142 SCTP_IERROR_STALE_COOKIE, 143 SCTP_IERROR_NOMEM, 144 SCTP_IERROR_MALFORMED, 145 SCTP_IERROR_BAD_TAG, 146 SCTP_IERROR_BIG_GAP, 147 SCTP_IERROR_DUP_TSN, 148 SCTP_IERROR_HIGH_TSN, 149 SCTP_IERROR_IGNORE_TSN, 150 SCTP_IERROR_NO_DATA, 151 SCTP_IERROR_BAD_STREAM, 152 SCTP_IERROR_BAD_PORTS, 153 SCTP_IERROR_AUTH_BAD_HMAC, 154 SCTP_IERROR_AUTH_BAD_KEYID, 155 SCTP_IERROR_PROTO_VIOLATION, 156 SCTP_IERROR_ERROR, 157 SCTP_IERROR_ABORT, 158 }; 159 160 161 162 /* SCTP state defines for internal state machine */ 163 enum sctp_state { 164 165 SCTP_STATE_CLOSED = 0, 166 SCTP_STATE_COOKIE_WAIT = 1, 167 SCTP_STATE_COOKIE_ECHOED = 2, 168 SCTP_STATE_ESTABLISHED = 3, 169 SCTP_STATE_SHUTDOWN_PENDING = 4, 170 SCTP_STATE_SHUTDOWN_SENT = 5, 171 SCTP_STATE_SHUTDOWN_RECEIVED = 6, 172 SCTP_STATE_SHUTDOWN_ACK_SENT = 7, 173 174 }; 175 176 #define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT 177 #define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1) 178 179 /* These are values for sk->state. 180 * For a UDP-style SCTP socket, the states are defined as follows 181 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 182 * accept new associations, but it can initiate the creation of new ones. 183 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 184 * accept new associations and can initiate the creation of new ones. 185 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off 186 * socket with one association. 187 * For a TCP-style SCTP socket, the states are defined as follows 188 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 189 * accept new associations, but it can initiate the creation of new ones. 190 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 191 * accept new associations, but cannot initiate the creation of new ones. 192 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single 193 * association. 194 */ 195 enum sctp_sock_state { 196 SCTP_SS_CLOSED = TCP_CLOSE, 197 SCTP_SS_LISTENING = TCP_LISTEN, 198 SCTP_SS_ESTABLISHING = TCP_SYN_SENT, 199 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED, 200 SCTP_SS_CLOSING = TCP_CLOSE_WAIT, 201 }; 202 203 /* These functions map various type to printable names. */ 204 const char *sctp_cname(const union sctp_subtype id); /* chunk types */ 205 const char *sctp_oname(const union sctp_subtype id); /* other events */ 206 const char *sctp_tname(const union sctp_subtype id); /* timeouts */ 207 const char *sctp_pname(const union sctp_subtype id); /* primitives */ 208 209 /* This is a table of printable names of sctp_state_t's. */ 210 extern const char *const sctp_state_tbl[]; 211 extern const char *const sctp_evttype_tbl[]; 212 extern const char *const sctp_status_tbl[]; 213 214 /* Maximum chunk length considering padding requirements. */ 215 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) }; 216 217 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little 218 * harder (until reaching ESTABLISHED state). 219 */ 220 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 }; 221 222 /* Guess at how big to make the TSN mapping array. 223 * We guarantee that we can handle at least this big a gap between the 224 * cumulative ACK and the highest TSN. In practice, we can often 225 * handle up to twice this value. 226 * 227 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a 228 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE 229 * must be less than 65535 (2^16 - 1), or we will have overflow 230 * problems creating SACK's. 231 */ 232 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG 233 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL 234 #define SCTP_TSN_MAP_SIZE 4096 235 236 /* We will not record more than this many duplicate TSNs between two 237 * SACKs. The minimum PMTU is 512. Remove all the headers and there 238 * is enough room for 117 duplicate reports. Round down to the 239 * nearest power of 2. 240 */ 241 enum { SCTP_MAX_DUP_TSNS = 16 }; 242 enum { SCTP_MAX_GABS = 16 }; 243 244 /* Heartbeat interval - 30 secs */ 245 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT (30*1000) 246 247 /* Delayed sack timer - 200ms */ 248 #define SCTP_DEFAULT_TIMEOUT_SACK (200) 249 250 /* RTO.Initial - 3 seconds 251 * RTO.Min - 1 second 252 * RTO.Max - 60 seconds 253 * RTO.Alpha - 1/8 254 * RTO.Beta - 1/4 255 */ 256 #define SCTP_RTO_INITIAL (3 * 1000) 257 #define SCTP_RTO_MIN (1 * 1000) 258 #define SCTP_RTO_MAX (60 * 1000) 259 260 #define SCTP_RTO_ALPHA 3 /* 1/8 when converted to right shifts. */ 261 #define SCTP_RTO_BETA 2 /* 1/4 when converted to right shifts. */ 262 263 /* Maximum number of new data packets that can be sent in a burst. */ 264 #define SCTP_DEFAULT_MAX_BURST 4 265 266 #define SCTP_CLOCK_GRANULARITY 1 /* 1 jiffy */ 267 268 #define SCTP_DEFAULT_COOKIE_LIFE (60 * 1000) /* 60 seconds */ 269 270 #define SCTP_DEFAULT_MINWINDOW 1500 /* default minimum rwnd size */ 271 #define SCTP_DEFAULT_MAXWINDOW 65535 /* default rwnd size */ 272 #define SCTP_DEFAULT_RWND_SHIFT 4 /* by default, update on 1/16 of 273 * rcvbuf, which is 1/8 of initial 274 * window 275 */ 276 #define SCTP_DEFAULT_MAXSEGMENT 1500 /* MTU size, this is the limit 277 * to which we will raise the P-MTU. 278 */ 279 #define SCTP_DEFAULT_MINSEGMENT 512 /* MTU size ... if no mtu disc */ 280 281 #define SCTP_SECRET_SIZE 32 /* Number of octets in a 256 bits. */ 282 283 #define SCTP_SIGNATURE_SIZE 20 /* size of a SLA-1 signature */ 284 285 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash 286 * functions simpler to write. 287 */ 288 289 /* These are the values for pf exposure, UNUSED is to keep compatible with old 290 * applications by default. 291 */ 292 enum { 293 SCTP_PF_EXPOSE_UNSET, 294 SCTP_PF_EXPOSE_DISABLE, 295 SCTP_PF_EXPOSE_ENABLE, 296 }; 297 #define SCTP_PF_EXPOSE_MAX SCTP_PF_EXPOSE_ENABLE 298 299 #define SCTP_PS_RETRANS_MAX 0xffff 300 301 /* These return values describe the success or failure of a number of 302 * routines which form the lower interface to SCTP_outqueue. 303 */ 304 enum sctp_xmit { 305 SCTP_XMIT_OK, 306 SCTP_XMIT_PMTU_FULL, 307 SCTP_XMIT_RWND_FULL, 308 SCTP_XMIT_DELAY, 309 }; 310 311 /* These are the commands for manipulating transports. */ 312 enum sctp_transport_cmd { 313 SCTP_TRANSPORT_UP, 314 SCTP_TRANSPORT_DOWN, 315 SCTP_TRANSPORT_PF, 316 }; 317 318 /* These are the address scopes defined mainly for IPv4 addresses 319 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>. 320 * These scopes are hopefully generic enough to be used on scoping both 321 * IPv4 and IPv6 addresses in SCTP. 322 * At this point, the IPv6 scopes will be mapped to these internal scopes 323 * as much as possible. 324 */ 325 enum sctp_scope { 326 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */ 327 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */ 328 SCTP_SCOPE_LINK, /* IPv4 link local address */ 329 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */ 330 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */ 331 }; 332 333 enum { 334 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */ 335 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */ 336 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */ 337 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */ 338 }; 339 340 #define SCTP_SCOPE_POLICY_MAX SCTP_SCOPE_POLICY_LINK 341 342 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>, 343 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24, 344 * 192.88.99.0/24. 345 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP 346 * addresses. 347 */ 348 #define IS_IPV4_UNUSABLE_ADDRESS(a) \ 349 ((htonl(INADDR_BROADCAST) == a) || \ 350 ipv4_is_multicast(a) || \ 351 ipv4_is_zeronet(a) || \ 352 ipv4_is_test_198(a) || \ 353 ipv4_is_anycast_6to4(a)) 354 355 /* Flags used for the bind address copy functions. */ 356 #define SCTP_ADDR4_ALLOWED 0x00000001 /* IPv4 address is allowed by 357 local sock family */ 358 #define SCTP_ADDR6_ALLOWED 0x00000002 /* IPv6 address is allowed by 359 local sock family */ 360 #define SCTP_ADDR4_PEERSUPP 0x00000004 /* IPv4 address is supported by 361 peer */ 362 #define SCTP_ADDR6_PEERSUPP 0x00000008 /* IPv6 address is supported by 363 peer */ 364 365 /* Reasons to retransmit. */ 366 enum sctp_retransmit_reason { 367 SCTP_RTXR_T3_RTX, 368 SCTP_RTXR_FAST_RTX, 369 SCTP_RTXR_PMTUD, 370 SCTP_RTXR_T1_RTX, 371 }; 372 373 /* Reasons to lower cwnd. */ 374 enum sctp_lower_cwnd { 375 SCTP_LOWER_CWND_T3_RTX, 376 SCTP_LOWER_CWND_FAST_RTX, 377 SCTP_LOWER_CWND_ECNE, 378 SCTP_LOWER_CWND_INACTIVE, 379 }; 380 381 382 /* SCTP-AUTH Necessary constants */ 383 384 /* SCTP-AUTH, Section 3.3 385 * 386 * The following Table 2 shows the currently defined values for HMAC 387 * identifiers. 388 * 389 * +-----------------+--------------------------+ 390 * | HMAC Identifier | Message Digest Algorithm | 391 * +-----------------+--------------------------+ 392 * | 0 | Reserved | 393 * | 1 | SHA-1 defined in [8] | 394 * | 2 | Reserved | 395 * | 3 | SHA-256 defined in [8] | 396 * +-----------------+--------------------------+ 397 */ 398 enum { 399 SCTP_AUTH_HMAC_ID_RESERVED_0, 400 SCTP_AUTH_HMAC_ID_SHA1, 401 SCTP_AUTH_HMAC_ID_RESERVED_2, 402 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE) 403 SCTP_AUTH_HMAC_ID_SHA256, 404 #endif 405 __SCTP_AUTH_HMAC_MAX 406 }; 407 408 #define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1 409 #define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX 410 #define SCTP_SHA1_SIG_SIZE 20 411 #define SCTP_SHA256_SIG_SIZE 32 412 413 /* SCTP-AUTH, Section 3.2 414 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks 415 * MUST NOT be listed in the CHUNKS parameter 416 */ 417 #define SCTP_NUM_NOAUTH_CHUNKS 4 418 #define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS) 419 420 /* SCTP-AUTH Section 6.1 421 * The RANDOM parameter MUST contain a 32 byte random number. 422 */ 423 #define SCTP_AUTH_RANDOM_LENGTH 32 424 425 #endif /* __sctp_constants_h__ */ 426