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. */ 33enum { SCTP_MAX_STREAM = 0xffff }; 34enum { SCTP_DEFAULT_OUTSTREAMS = 10 }; 35enum { 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. */ 59enum 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 70enum 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_PROBE, 81 SCTP_EVENT_TIMEOUT_SACK, 82 SCTP_EVENT_TIMEOUT_AUTOCLOSE, 83}; 84 85#define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE 86#define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1) 87 88enum sctp_event_other { 89 SCTP_EVENT_NO_PENDING_TSN = 0, 90 SCTP_EVENT_ICMP_PROTO_UNREACH, 91}; 92 93#define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH 94#define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1) 95 96/* These are primitive requests from the ULP. */ 97enum sctp_event_primitive { 98 SCTP_PRIMITIVE_ASSOCIATE = 0, 99 SCTP_PRIMITIVE_SHUTDOWN, 100 SCTP_PRIMITIVE_ABORT, 101 SCTP_PRIMITIVE_SEND, 102 SCTP_PRIMITIVE_REQUESTHEARTBEAT, 103 SCTP_PRIMITIVE_ASCONF, 104 SCTP_PRIMITIVE_RECONF, 105}; 106 107#define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_RECONF 108#define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1) 109 110/* We define here a utility type for manipulating subtypes. 111 * The subtype constructors all work like this: 112 * 113 * union sctp_subtype foo = SCTP_ST_CHUNK(SCTP_CID_INIT); 114 */ 115 116union sctp_subtype { 117 enum sctp_cid chunk; 118 enum sctp_event_timeout timeout; 119 enum sctp_event_other other; 120 enum sctp_event_primitive primitive; 121}; 122 123#define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \ 124static inline union sctp_subtype \ 125SCTP_ST_## _name (_type _arg) \ 126{ union sctp_subtype _retval; _retval._elt = _arg; return _retval; } 127 128SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, enum sctp_cid, chunk) 129SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, enum sctp_event_timeout, timeout) 130SCTP_SUBTYPE_CONSTRUCTOR(OTHER, enum sctp_event_other, other) 131SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, enum sctp_event_primitive, primitive) 132 133 134#define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA || \ 135 a->chunk_hdr->type == SCTP_CID_I_DATA) 136 137/* Internal error codes */ 138enum sctp_ierror { 139 SCTP_IERROR_NO_ERROR = 0, 140 SCTP_IERROR_BASE = 1000, 141 SCTP_IERROR_NO_COOKIE, 142 SCTP_IERROR_BAD_SIG, 143 SCTP_IERROR_STALE_COOKIE, 144 SCTP_IERROR_NOMEM, 145 SCTP_IERROR_MALFORMED, 146 SCTP_IERROR_BAD_TAG, 147 SCTP_IERROR_BIG_GAP, 148 SCTP_IERROR_DUP_TSN, 149 SCTP_IERROR_HIGH_TSN, 150 SCTP_IERROR_IGNORE_TSN, 151 SCTP_IERROR_NO_DATA, 152 SCTP_IERROR_BAD_STREAM, 153 SCTP_IERROR_BAD_PORTS, 154 SCTP_IERROR_AUTH_BAD_HMAC, 155 SCTP_IERROR_AUTH_BAD_KEYID, 156 SCTP_IERROR_PROTO_VIOLATION, 157 SCTP_IERROR_ERROR, 158 SCTP_IERROR_ABORT, 159}; 160 161 162 163/* SCTP state defines for internal state machine */ 164enum sctp_state { 165 166 SCTP_STATE_CLOSED = 0, 167 SCTP_STATE_COOKIE_WAIT = 1, 168 SCTP_STATE_COOKIE_ECHOED = 2, 169 SCTP_STATE_ESTABLISHED = 3, 170 SCTP_STATE_SHUTDOWN_PENDING = 4, 171 SCTP_STATE_SHUTDOWN_SENT = 5, 172 SCTP_STATE_SHUTDOWN_RECEIVED = 6, 173 SCTP_STATE_SHUTDOWN_ACK_SENT = 7, 174 175}; 176 177#define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT 178#define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1) 179 180/* These are values for sk->state. 181 * For a UDP-style SCTP socket, the states are defined as follows 182 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 183 * accept new associations, but it can initiate the creation of new ones. 184 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 185 * accept new associations and can initiate the creation of new ones. 186 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off 187 * socket with one association. 188 * For a TCP-style SCTP socket, the states are defined as follows 189 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 190 * accept new associations, but it can initiate the creation of new ones. 191 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 192 * accept new associations, but cannot initiate the creation of new ones. 193 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single 194 * association. 195 */ 196enum sctp_sock_state { 197 SCTP_SS_CLOSED = TCP_CLOSE, 198 SCTP_SS_LISTENING = TCP_LISTEN, 199 SCTP_SS_ESTABLISHING = TCP_SYN_SENT, 200 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED, 201 SCTP_SS_CLOSING = TCP_CLOSE_WAIT, 202}; 203 204enum sctp_plpmtud_state { 205 SCTP_PL_DISABLED, 206 SCTP_PL_BASE, 207 SCTP_PL_SEARCH, 208 SCTP_PL_COMPLETE, 209 SCTP_PL_ERROR, 210}; 211 212#define SCTP_BASE_PLPMTU 1200 213#define SCTP_MAX_PLPMTU 9000 214#define SCTP_MIN_PLPMTU 512 215 216#define SCTP_MAX_PROBES 3 217 218#define SCTP_PL_BIG_STEP 32 219#define SCTP_PL_MIN_STEP 4 220 221/* These functions map various type to printable names. */ 222const char *sctp_cname(const union sctp_subtype id); /* chunk types */ 223const char *sctp_oname(const union sctp_subtype id); /* other events */ 224const char *sctp_tname(const union sctp_subtype id); /* timeouts */ 225const char *sctp_pname(const union sctp_subtype id); /* primitives */ 226 227/* This is a table of printable names of sctp_state_t's. */ 228extern const char *const sctp_state_tbl[]; 229extern const char *const sctp_evttype_tbl[]; 230extern const char *const sctp_status_tbl[]; 231 232/* Maximum chunk length considering padding requirements. */ 233enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) }; 234 235/* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little 236 * harder (until reaching ESTABLISHED state). 237 */ 238enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 }; 239 240/* Guess at how big to make the TSN mapping array. 241 * We guarantee that we can handle at least this big a gap between the 242 * cumulative ACK and the highest TSN. In practice, we can often 243 * handle up to twice this value. 244 * 245 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a 246 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE 247 * must be less than 65535 (2^16 - 1), or we will have overflow 248 * problems creating SACK's. 249 */ 250#define SCTP_TSN_MAP_INITIAL BITS_PER_LONG 251#define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL 252#define SCTP_TSN_MAP_SIZE 4096 253 254/* We will not record more than this many duplicate TSNs between two 255 * SACKs. The minimum PMTU is 512. Remove all the headers and there 256 * is enough room for 117 duplicate reports. Round down to the 257 * nearest power of 2. 258 */ 259enum { SCTP_MAX_DUP_TSNS = 16 }; 260enum { SCTP_MAX_GABS = 16 }; 261 262/* Heartbeat interval - 30 secs */ 263#define SCTP_DEFAULT_TIMEOUT_HEARTBEAT (30*1000) 264 265/* Delayed sack timer - 200ms */ 266#define SCTP_DEFAULT_TIMEOUT_SACK (200) 267 268/* RTO.Initial - 3 seconds 269 * RTO.Min - 1 second 270 * RTO.Max - 60 seconds 271 * RTO.Alpha - 1/8 272 * RTO.Beta - 1/4 273 */ 274#define SCTP_RTO_INITIAL (3 * 1000) 275#define SCTP_RTO_MIN (1 * 1000) 276#define SCTP_RTO_MAX (60 * 1000) 277 278#define SCTP_RTO_ALPHA 3 /* 1/8 when converted to right shifts. */ 279#define SCTP_RTO_BETA 2 /* 1/4 when converted to right shifts. */ 280 281/* Maximum number of new data packets that can be sent in a burst. */ 282#define SCTP_DEFAULT_MAX_BURST 4 283 284#define SCTP_CLOCK_GRANULARITY 1 /* 1 jiffy */ 285 286#define SCTP_DEFAULT_COOKIE_LIFE (60 * 1000) /* 60 seconds */ 287 288#define SCTP_DEFAULT_MINWINDOW 1500 /* default minimum rwnd size */ 289#define SCTP_DEFAULT_MAXWINDOW 65535 /* default rwnd size */ 290#define SCTP_DEFAULT_RWND_SHIFT 4 /* by default, update on 1/16 of 291 * rcvbuf, which is 1/8 of initial 292 * window 293 */ 294#define SCTP_DEFAULT_MAXSEGMENT 1500 /* MTU size, this is the limit 295 * to which we will raise the P-MTU. 296 */ 297#define SCTP_DEFAULT_MINSEGMENT 512 /* MTU size ... if no mtu disc */ 298 299#define SCTP_SECRET_SIZE 32 /* Number of octets in a 256 bits. */ 300 301#define SCTP_SIGNATURE_SIZE 20 /* size of a SLA-1 signature */ 302 303#define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash 304 * functions simpler to write. 305 */ 306 307#define SCTP_DEFAULT_UDP_PORT 9899 /* default UDP tunneling port */ 308 309/* These are the values for pf exposure, UNUSED is to keep compatible with old 310 * applications by default. 311 */ 312enum { 313 SCTP_PF_EXPOSE_UNSET, 314 SCTP_PF_EXPOSE_DISABLE, 315 SCTP_PF_EXPOSE_ENABLE, 316}; 317#define SCTP_PF_EXPOSE_MAX SCTP_PF_EXPOSE_ENABLE 318 319#define SCTP_PS_RETRANS_MAX 0xffff 320 321/* These return values describe the success or failure of a number of 322 * routines which form the lower interface to SCTP_outqueue. 323 */ 324enum sctp_xmit { 325 SCTP_XMIT_OK, 326 SCTP_XMIT_PMTU_FULL, 327 SCTP_XMIT_RWND_FULL, 328 SCTP_XMIT_DELAY, 329}; 330 331/* These are the commands for manipulating transports. */ 332enum sctp_transport_cmd { 333 SCTP_TRANSPORT_UP, 334 SCTP_TRANSPORT_DOWN, 335 SCTP_TRANSPORT_PF, 336}; 337 338/* These are the address scopes defined mainly for IPv4 addresses 339 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>. 340 * These scopes are hopefully generic enough to be used on scoping both 341 * IPv4 and IPv6 addresses in SCTP. 342 * At this point, the IPv6 scopes will be mapped to these internal scopes 343 * as much as possible. 344 */ 345enum sctp_scope { 346 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */ 347 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */ 348 SCTP_SCOPE_LINK, /* IPv4 link local address */ 349 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */ 350 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */ 351}; 352 353enum { 354 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */ 355 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */ 356 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */ 357 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */ 358}; 359 360#define SCTP_SCOPE_POLICY_MAX SCTP_SCOPE_POLICY_LINK 361 362/* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>, 363 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 192.88.99.0/24. 364 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP 365 * addresses. 366 */ 367#define IS_IPV4_UNUSABLE_ADDRESS(a) \ 368 ((htonl(INADDR_BROADCAST) == a) || \ 369 ipv4_is_multicast(a) || \ 370 ipv4_is_zeronet(a) || \ 371 ipv4_is_anycast_6to4(a)) 372 373/* Flags used for the bind address copy functions. */ 374#define SCTP_ADDR4_ALLOWED 0x00000001 /* IPv4 address is allowed by 375 local sock family */ 376#define SCTP_ADDR6_ALLOWED 0x00000002 /* IPv6 address is allowed by 377 local sock family */ 378#define SCTP_ADDR4_PEERSUPP 0x00000004 /* IPv4 address is supported by 379 peer */ 380#define SCTP_ADDR6_PEERSUPP 0x00000008 /* IPv6 address is supported by 381 peer */ 382 383/* Reasons to retransmit. */ 384enum sctp_retransmit_reason { 385 SCTP_RTXR_T3_RTX, 386 SCTP_RTXR_FAST_RTX, 387 SCTP_RTXR_PMTUD, 388 SCTP_RTXR_T1_RTX, 389}; 390 391/* Reasons to lower cwnd. */ 392enum sctp_lower_cwnd { 393 SCTP_LOWER_CWND_T3_RTX, 394 SCTP_LOWER_CWND_FAST_RTX, 395 SCTP_LOWER_CWND_ECNE, 396 SCTP_LOWER_CWND_INACTIVE, 397}; 398 399 400/* SCTP-AUTH Necessary constants */ 401 402/* SCTP-AUTH, Section 3.3 403 * 404 * The following Table 2 shows the currently defined values for HMAC 405 * identifiers. 406 * 407 * +-----------------+--------------------------+ 408 * | HMAC Identifier | Message Digest Algorithm | 409 * +-----------------+--------------------------+ 410 * | 0 | Reserved | 411 * | 1 | SHA-1 defined in [8] | 412 * | 2 | Reserved | 413 * | 3 | SHA-256 defined in [8] | 414 * +-----------------+--------------------------+ 415 */ 416enum { 417 SCTP_AUTH_HMAC_ID_RESERVED_0, 418 SCTP_AUTH_HMAC_ID_SHA1, 419 SCTP_AUTH_HMAC_ID_RESERVED_2, 420#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE) 421 SCTP_AUTH_HMAC_ID_SHA256, 422#endif 423 __SCTP_AUTH_HMAC_MAX 424}; 425 426#define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1 427#define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX 428#define SCTP_SHA1_SIG_SIZE 20 429#define SCTP_SHA256_SIG_SIZE 32 430 431/* SCTP-AUTH, Section 3.2 432 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks 433 * MUST NOT be listed in the CHUNKS parameter 434 */ 435#define SCTP_NUM_NOAUTH_CHUNKS 4 436#define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS) 437 438/* SCTP-AUTH Section 6.1 439 * The RANDOM parameter MUST contain a 32 byte random number. 440 */ 441#define SCTP_AUTH_RANDOM_LENGTH 32 442 443#define SCTP_PROBE_TIMER_MIN 5000 444 445#endif /* __sctp_constants_h__ */ 446