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 * This SCTP implementation is free software; 10 * you can redistribute it and/or modify it under the terms of 11 * the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * This SCTP implementation is distributed in the hope that it 16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 17 * ************************ 18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 19 * See the GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with GNU CC; see the file COPYING. If not, see 23 * <http://www.gnu.org/licenses/>. 24 * 25 * Please send any bug reports or fixes you make to the 26 * email address(es): 27 * lksctp developers <linux-sctp@vger.kernel.org> 28 * 29 * Written or modified by: 30 * La Monte H.P. Yarroll <piggy@acm.org> 31 * Karl Knutson <karl@athena.chicago.il.us> 32 * Randall Stewart <randall@stewart.chicago.il.us> 33 * Ken Morneau <kmorneau@cisco.com> 34 * Qiaobing Xie <qxie1@motorola.com> 35 * Xingang Guo <xingang.guo@intel.com> 36 * Sridhar Samudrala <samudrala@us.ibm.com> 37 * Daisy Chang <daisyc@us.ibm.com> 38 */ 39 40 #ifndef __sctp_constants_h__ 41 #define __sctp_constants_h__ 42 43 #include <linux/sctp.h> 44 #include <linux/ipv6.h> /* For ipv6hdr. */ 45 #include <net/tcp_states.h> /* For TCP states used in sctp_sock_state_t */ 46 47 /* Value used for stream negotiation. */ 48 enum { SCTP_MAX_STREAM = 0xffff }; 49 enum { SCTP_DEFAULT_OUTSTREAMS = 10 }; 50 enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM }; 51 52 /* Since CIDs are sparse, we need all four of the following 53 * symbols. CIDs are dense through SCTP_CID_BASE_MAX. 54 */ 55 #define SCTP_CID_BASE_MAX SCTP_CID_SHUTDOWN_COMPLETE 56 57 #define SCTP_NUM_BASE_CHUNK_TYPES (SCTP_CID_BASE_MAX + 1) 58 59 #define SCTP_NUM_ADDIP_CHUNK_TYPES 2 60 61 #define SCTP_NUM_PRSCTP_CHUNK_TYPES 1 62 63 #define SCTP_NUM_RECONF_CHUNK_TYPES 1 64 65 #define SCTP_NUM_AUTH_CHUNK_TYPES 1 66 67 #define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNK_TYPES + \ 68 SCTP_NUM_ADDIP_CHUNK_TYPES +\ 69 SCTP_NUM_PRSCTP_CHUNK_TYPES +\ 70 SCTP_NUM_RECONF_CHUNK_TYPES +\ 71 SCTP_NUM_AUTH_CHUNK_TYPES) 72 73 /* These are the different flavours of event. */ 74 typedef enum { 75 76 SCTP_EVENT_T_CHUNK = 1, 77 SCTP_EVENT_T_TIMEOUT, 78 SCTP_EVENT_T_OTHER, 79 SCTP_EVENT_T_PRIMITIVE 80 81 } sctp_event_t; 82 83 /* As a convenience for the state machine, we append SCTP_EVENT_* and 84 * SCTP_ULP_* to the list of possible chunks. 85 */ 86 87 typedef enum { 88 SCTP_EVENT_TIMEOUT_NONE = 0, 89 SCTP_EVENT_TIMEOUT_T1_COOKIE, 90 SCTP_EVENT_TIMEOUT_T1_INIT, 91 SCTP_EVENT_TIMEOUT_T2_SHUTDOWN, 92 SCTP_EVENT_TIMEOUT_T3_RTX, 93 SCTP_EVENT_TIMEOUT_T4_RTO, 94 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD, 95 SCTP_EVENT_TIMEOUT_HEARTBEAT, 96 SCTP_EVENT_TIMEOUT_RECONF, 97 SCTP_EVENT_TIMEOUT_SACK, 98 SCTP_EVENT_TIMEOUT_AUTOCLOSE, 99 } sctp_event_timeout_t; 100 101 #define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE 102 #define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1) 103 104 typedef enum { 105 SCTP_EVENT_NO_PENDING_TSN = 0, 106 SCTP_EVENT_ICMP_PROTO_UNREACH, 107 } sctp_event_other_t; 108 109 #define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH 110 #define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1) 111 112 /* These are primitive requests from the ULP. */ 113 typedef enum { 114 SCTP_PRIMITIVE_ASSOCIATE = 0, 115 SCTP_PRIMITIVE_SHUTDOWN, 116 SCTP_PRIMITIVE_ABORT, 117 SCTP_PRIMITIVE_SEND, 118 SCTP_PRIMITIVE_REQUESTHEARTBEAT, 119 SCTP_PRIMITIVE_ASCONF, 120 SCTP_PRIMITIVE_RECONF, 121 } sctp_event_primitive_t; 122 123 #define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_RECONF 124 #define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1) 125 126 /* We define here a utility type for manipulating subtypes. 127 * The subtype constructors all work like this: 128 * 129 * sctp_subtype_t foo = SCTP_ST_CHUNK(SCTP_CID_INIT); 130 */ 131 132 typedef union { 133 enum sctp_cid chunk; 134 sctp_event_timeout_t timeout; 135 sctp_event_other_t other; 136 sctp_event_primitive_t primitive; 137 } sctp_subtype_t; 138 139 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \ 140 static inline sctp_subtype_t \ 141 SCTP_ST_## _name (_type _arg) \ 142 { sctp_subtype_t _retval; _retval._elt = _arg; return _retval; } 143 144 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, enum sctp_cid, chunk) 145 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, sctp_event_timeout_t, timeout) 146 SCTP_SUBTYPE_CONSTRUCTOR(OTHER, sctp_event_other_t, other) 147 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, sctp_event_primitive_t, primitive) 148 149 150 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA) 151 152 /* Calculate the actual data size in a data chunk */ 153 #define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\ 154 - (unsigned long)(c->chunk_hdr)\ 155 - sizeof(struct sctp_data_chunk))) 156 157 /* Internal error codes */ 158 typedef enum { 159 160 SCTP_IERROR_NO_ERROR = 0, 161 SCTP_IERROR_BASE = 1000, 162 SCTP_IERROR_NO_COOKIE, 163 SCTP_IERROR_BAD_SIG, 164 SCTP_IERROR_STALE_COOKIE, 165 SCTP_IERROR_NOMEM, 166 SCTP_IERROR_MALFORMED, 167 SCTP_IERROR_BAD_TAG, 168 SCTP_IERROR_BIG_GAP, 169 SCTP_IERROR_DUP_TSN, 170 SCTP_IERROR_HIGH_TSN, 171 SCTP_IERROR_IGNORE_TSN, 172 SCTP_IERROR_NO_DATA, 173 SCTP_IERROR_BAD_STREAM, 174 SCTP_IERROR_BAD_PORTS, 175 SCTP_IERROR_AUTH_BAD_HMAC, 176 SCTP_IERROR_AUTH_BAD_KEYID, 177 SCTP_IERROR_PROTO_VIOLATION, 178 SCTP_IERROR_ERROR, 179 SCTP_IERROR_ABORT, 180 } sctp_ierror_t; 181 182 183 184 /* SCTP state defines for internal state machine */ 185 typedef enum { 186 187 SCTP_STATE_CLOSED = 0, 188 SCTP_STATE_COOKIE_WAIT = 1, 189 SCTP_STATE_COOKIE_ECHOED = 2, 190 SCTP_STATE_ESTABLISHED = 3, 191 SCTP_STATE_SHUTDOWN_PENDING = 4, 192 SCTP_STATE_SHUTDOWN_SENT = 5, 193 SCTP_STATE_SHUTDOWN_RECEIVED = 6, 194 SCTP_STATE_SHUTDOWN_ACK_SENT = 7, 195 196 } sctp_state_t; 197 198 #define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT 199 #define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1) 200 201 /* These are values for sk->state. 202 * For a UDP-style SCTP socket, the states are defined as follows 203 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 204 * accept new associations, but it can initiate the creation of new ones. 205 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 206 * accept new associations and can initiate the creation of new ones. 207 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off 208 * socket with one association. 209 * For a TCP-style SCTP socket, the states are defined as follows 210 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 211 * accept new associations, but it can initiate the creation of new ones. 212 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 213 * accept new associations, but cannot initiate the creation of new ones. 214 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single 215 * association. 216 */ 217 typedef enum { 218 SCTP_SS_CLOSED = TCP_CLOSE, 219 SCTP_SS_LISTENING = TCP_LISTEN, 220 SCTP_SS_ESTABLISHING = TCP_SYN_SENT, 221 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED, 222 SCTP_SS_CLOSING = TCP_CLOSE_WAIT, 223 } sctp_sock_state_t; 224 225 /* These functions map various type to printable names. */ 226 const char *sctp_cname(const sctp_subtype_t); /* chunk types */ 227 const char *sctp_oname(const sctp_subtype_t); /* other events */ 228 const char *sctp_tname(const sctp_subtype_t); /* timeouts */ 229 const char *sctp_pname(const sctp_subtype_t); /* primitives */ 230 231 /* This is a table of printable names of sctp_state_t's. */ 232 extern const char *const sctp_state_tbl[]; 233 extern const char *const sctp_evttype_tbl[]; 234 extern const char *const sctp_status_tbl[]; 235 236 /* Maximum chunk length considering padding requirements. */ 237 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) }; 238 239 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little 240 * harder (until reaching ESTABLISHED state). 241 */ 242 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 }; 243 244 /* Guess at how big to make the TSN mapping array. 245 * We guarantee that we can handle at least this big a gap between the 246 * cumulative ACK and the highest TSN. In practice, we can often 247 * handle up to twice this value. 248 * 249 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a 250 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE 251 * must be less than 65535 (2^16 - 1), or we will have overflow 252 * problems creating SACK's. 253 */ 254 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG 255 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL 256 #define SCTP_TSN_MAP_SIZE 4096 257 258 /* We will not record more than this many duplicate TSNs between two 259 * SACKs. The minimum PMTU is 576. Remove all the headers and there 260 * is enough room for 131 duplicate reports. Round down to the 261 * nearest power of 2. 262 */ 263 enum { SCTP_MIN_PMTU = 576 }; 264 enum { SCTP_MAX_DUP_TSNS = 16 }; 265 enum { SCTP_MAX_GABS = 16 }; 266 267 /* Heartbeat interval - 30 secs */ 268 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT (30*1000) 269 270 /* Delayed sack timer - 200ms */ 271 #define SCTP_DEFAULT_TIMEOUT_SACK (200) 272 273 /* RTO.Initial - 3 seconds 274 * RTO.Min - 1 second 275 * RTO.Max - 60 seconds 276 * RTO.Alpha - 1/8 277 * RTO.Beta - 1/4 278 */ 279 #define SCTP_RTO_INITIAL (3 * 1000) 280 #define SCTP_RTO_MIN (1 * 1000) 281 #define SCTP_RTO_MAX (60 * 1000) 282 283 #define SCTP_RTO_ALPHA 3 /* 1/8 when converted to right shifts. */ 284 #define SCTP_RTO_BETA 2 /* 1/4 when converted to right shifts. */ 285 286 /* Maximum number of new data packets that can be sent in a burst. */ 287 #define SCTP_DEFAULT_MAX_BURST 4 288 289 #define SCTP_CLOCK_GRANULARITY 1 /* 1 jiffy */ 290 291 #define SCTP_DEFAULT_COOKIE_LIFE (60 * 1000) /* 60 seconds */ 292 293 #define SCTP_DEFAULT_MINWINDOW 1500 /* default minimum rwnd size */ 294 #define SCTP_DEFAULT_MAXWINDOW 65535 /* default rwnd size */ 295 #define SCTP_DEFAULT_RWND_SHIFT 4 /* by default, update on 1/16 of 296 * rcvbuf, which is 1/8 of initial 297 * window 298 */ 299 #define SCTP_DEFAULT_MAXSEGMENT 1500 /* MTU size, this is the limit 300 * to which we will raise the P-MTU. 301 */ 302 #define SCTP_DEFAULT_MINSEGMENT 512 /* MTU size ... if no mtu disc */ 303 304 #define SCTP_SECRET_SIZE 32 /* Number of octets in a 256 bits. */ 305 306 #define SCTP_SIGNATURE_SIZE 20 /* size of a SLA-1 signature */ 307 308 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash 309 * functions simpler to write. 310 */ 311 312 /* These return values describe the success or failure of a number of 313 * routines which form the lower interface to SCTP_outqueue. 314 */ 315 typedef enum { 316 SCTP_XMIT_OK, 317 SCTP_XMIT_PMTU_FULL, 318 SCTP_XMIT_RWND_FULL, 319 SCTP_XMIT_DELAY, 320 } sctp_xmit_t; 321 322 /* These are the commands for manipulating transports. */ 323 typedef enum { 324 SCTP_TRANSPORT_UP, 325 SCTP_TRANSPORT_DOWN, 326 SCTP_TRANSPORT_PF, 327 } sctp_transport_cmd_t; 328 329 /* These are the address scopes defined mainly for IPv4 addresses 330 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>. 331 * These scopes are hopefully generic enough to be used on scoping both 332 * IPv4 and IPv6 addresses in SCTP. 333 * At this point, the IPv6 scopes will be mapped to these internal scopes 334 * as much as possible. 335 */ 336 typedef enum { 337 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */ 338 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */ 339 SCTP_SCOPE_LINK, /* IPv4 link local address */ 340 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */ 341 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */ 342 } sctp_scope_t; 343 344 typedef enum { 345 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */ 346 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */ 347 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */ 348 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */ 349 } sctp_scope_policy_t; 350 351 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>, 352 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24, 353 * 192.88.99.0/24. 354 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP 355 * addresses. 356 */ 357 #define IS_IPV4_UNUSABLE_ADDRESS(a) \ 358 ((htonl(INADDR_BROADCAST) == a) || \ 359 ipv4_is_multicast(a) || \ 360 ipv4_is_zeronet(a) || \ 361 ipv4_is_test_198(a) || \ 362 ipv4_is_anycast_6to4(a)) 363 364 /* Flags used for the bind address copy functions. */ 365 #define SCTP_ADDR6_ALLOWED 0x00000001 /* IPv6 address is allowed by 366 local sock family */ 367 #define SCTP_ADDR4_PEERSUPP 0x00000002 /* IPv4 address is supported by 368 peer */ 369 #define SCTP_ADDR6_PEERSUPP 0x00000004 /* IPv6 address is supported by 370 peer */ 371 372 /* Reasons to retransmit. */ 373 typedef enum { 374 SCTP_RTXR_T3_RTX, 375 SCTP_RTXR_FAST_RTX, 376 SCTP_RTXR_PMTUD, 377 SCTP_RTXR_T1_RTX, 378 } sctp_retransmit_reason_t; 379 380 /* Reasons to lower cwnd. */ 381 typedef enum { 382 SCTP_LOWER_CWND_T3_RTX, 383 SCTP_LOWER_CWND_FAST_RTX, 384 SCTP_LOWER_CWND_ECNE, 385 SCTP_LOWER_CWND_INACTIVE, 386 } sctp_lower_cwnd_t; 387 388 389 /* SCTP-AUTH Necessary constants */ 390 391 /* SCTP-AUTH, Section 3.3 392 * 393 * The following Table 2 shows the currently defined values for HMAC 394 * identifiers. 395 * 396 * +-----------------+--------------------------+ 397 * | HMAC Identifier | Message Digest Algorithm | 398 * +-----------------+--------------------------+ 399 * | 0 | Reserved | 400 * | 1 | SHA-1 defined in [8] | 401 * | 2 | Reserved | 402 * | 3 | SHA-256 defined in [8] | 403 * +-----------------+--------------------------+ 404 */ 405 enum { 406 SCTP_AUTH_HMAC_ID_RESERVED_0, 407 SCTP_AUTH_HMAC_ID_SHA1, 408 SCTP_AUTH_HMAC_ID_RESERVED_2, 409 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE) 410 SCTP_AUTH_HMAC_ID_SHA256, 411 #endif 412 __SCTP_AUTH_HMAC_MAX 413 }; 414 415 #define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1 416 #define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX 417 #define SCTP_SHA1_SIG_SIZE 20 418 #define SCTP_SHA256_SIG_SIZE 32 419 420 /* SCTP-AUTH, Section 3.2 421 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks 422 * MUST NOT be listed in the CHUNKS parameter 423 */ 424 #define SCTP_NUM_NOAUTH_CHUNKS 4 425 #define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS) 426 427 /* SCTP-AUTH Section 6.1 428 * The RANDOM parameter MUST contain a 32 byte random number. 429 */ 430 #define SCTP_AUTH_RANDOM_LENGTH 32 431 432 #endif /* __sctp_constants_h__ */ 433