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. */ 48enum { SCTP_MAX_STREAM = 0xffff }; 49enum { SCTP_DEFAULT_OUTSTREAMS = 10 }; 50enum { 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_AUTH_CHUNK_TYPES 1 64 65#define SCTP_NUM_CHUNK_TYPES (SCTP_NUM_BASE_CHUNK_TYPES + \ 66 SCTP_NUM_ADDIP_CHUNK_TYPES +\ 67 SCTP_NUM_PRSCTP_CHUNK_TYPES +\ 68 SCTP_NUM_AUTH_CHUNK_TYPES) 69 70/* These are the different flavours of event. */ 71typedef enum { 72 73 SCTP_EVENT_T_CHUNK = 1, 74 SCTP_EVENT_T_TIMEOUT, 75 SCTP_EVENT_T_OTHER, 76 SCTP_EVENT_T_PRIMITIVE 77 78} sctp_event_t; 79 80/* As a convenience for the state machine, we append SCTP_EVENT_* and 81 * SCTP_ULP_* to the list of possible chunks. 82 */ 83 84typedef enum { 85 SCTP_EVENT_TIMEOUT_NONE = 0, 86 SCTP_EVENT_TIMEOUT_T1_COOKIE, 87 SCTP_EVENT_TIMEOUT_T1_INIT, 88 SCTP_EVENT_TIMEOUT_T2_SHUTDOWN, 89 SCTP_EVENT_TIMEOUT_T3_RTX, 90 SCTP_EVENT_TIMEOUT_T4_RTO, 91 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD, 92 SCTP_EVENT_TIMEOUT_HEARTBEAT, 93 SCTP_EVENT_TIMEOUT_SACK, 94 SCTP_EVENT_TIMEOUT_AUTOCLOSE, 95} sctp_event_timeout_t; 96 97#define SCTP_EVENT_TIMEOUT_MAX SCTP_EVENT_TIMEOUT_AUTOCLOSE 98#define SCTP_NUM_TIMEOUT_TYPES (SCTP_EVENT_TIMEOUT_MAX + 1) 99 100typedef enum { 101 SCTP_EVENT_NO_PENDING_TSN = 0, 102 SCTP_EVENT_ICMP_PROTO_UNREACH, 103} sctp_event_other_t; 104 105#define SCTP_EVENT_OTHER_MAX SCTP_EVENT_ICMP_PROTO_UNREACH 106#define SCTP_NUM_OTHER_TYPES (SCTP_EVENT_OTHER_MAX + 1) 107 108/* These are primitive requests from the ULP. */ 109typedef enum { 110 SCTP_PRIMITIVE_ASSOCIATE = 0, 111 SCTP_PRIMITIVE_SHUTDOWN, 112 SCTP_PRIMITIVE_ABORT, 113 SCTP_PRIMITIVE_SEND, 114 SCTP_PRIMITIVE_REQUESTHEARTBEAT, 115 SCTP_PRIMITIVE_ASCONF, 116} sctp_event_primitive_t; 117 118#define SCTP_EVENT_PRIMITIVE_MAX SCTP_PRIMITIVE_ASCONF 119#define SCTP_NUM_PRIMITIVE_TYPES (SCTP_EVENT_PRIMITIVE_MAX + 1) 120 121/* We define here a utility type for manipulating subtypes. 122 * The subtype constructors all work like this: 123 * 124 * sctp_subtype_t foo = SCTP_ST_CHUNK(SCTP_CID_INIT); 125 */ 126 127typedef union { 128 sctp_cid_t chunk; 129 sctp_event_timeout_t timeout; 130 sctp_event_other_t other; 131 sctp_event_primitive_t primitive; 132} sctp_subtype_t; 133 134#define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \ 135static inline sctp_subtype_t \ 136SCTP_ST_## _name (_type _arg) \ 137{ sctp_subtype_t _retval; _retval._elt = _arg; return _retval; } 138 139SCTP_SUBTYPE_CONSTRUCTOR(CHUNK, sctp_cid_t, chunk) 140SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT, sctp_event_timeout_t, timeout) 141SCTP_SUBTYPE_CONSTRUCTOR(OTHER, sctp_event_other_t, other) 142SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE, sctp_event_primitive_t, primitive) 143 144 145#define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA) 146 147/* Calculate the actual data size in a data chunk */ 148#define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\ 149 - (unsigned long)(c->chunk_hdr)\ 150 - sizeof(sctp_data_chunk_t))) 151 152/* Internal error codes */ 153typedef enum { 154 155 SCTP_IERROR_NO_ERROR = 0, 156 SCTP_IERROR_BASE = 1000, 157 SCTP_IERROR_NO_COOKIE, 158 SCTP_IERROR_BAD_SIG, 159 SCTP_IERROR_STALE_COOKIE, 160 SCTP_IERROR_NOMEM, 161 SCTP_IERROR_MALFORMED, 162 SCTP_IERROR_BAD_TAG, 163 SCTP_IERROR_BIG_GAP, 164 SCTP_IERROR_DUP_TSN, 165 SCTP_IERROR_HIGH_TSN, 166 SCTP_IERROR_IGNORE_TSN, 167 SCTP_IERROR_NO_DATA, 168 SCTP_IERROR_BAD_STREAM, 169 SCTP_IERROR_BAD_PORTS, 170 SCTP_IERROR_AUTH_BAD_HMAC, 171 SCTP_IERROR_AUTH_BAD_KEYID, 172 SCTP_IERROR_PROTO_VIOLATION, 173 SCTP_IERROR_ERROR, 174 SCTP_IERROR_ABORT, 175} sctp_ierror_t; 176 177 178 179/* SCTP state defines for internal state machine */ 180typedef enum { 181 182 SCTP_STATE_CLOSED = 0, 183 SCTP_STATE_COOKIE_WAIT = 1, 184 SCTP_STATE_COOKIE_ECHOED = 2, 185 SCTP_STATE_ESTABLISHED = 3, 186 SCTP_STATE_SHUTDOWN_PENDING = 4, 187 SCTP_STATE_SHUTDOWN_SENT = 5, 188 SCTP_STATE_SHUTDOWN_RECEIVED = 6, 189 SCTP_STATE_SHUTDOWN_ACK_SENT = 7, 190 191} sctp_state_t; 192 193#define SCTP_STATE_MAX SCTP_STATE_SHUTDOWN_ACK_SENT 194#define SCTP_STATE_NUM_STATES (SCTP_STATE_MAX + 1) 195 196/* These are values for sk->state. 197 * For a UDP-style SCTP socket, the states are defined as follows 198 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 199 * accept new associations, but it can initiate the creation of new ones. 200 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 201 * accept new associations and can initiate the creation of new ones. 202 * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off 203 * socket with one association. 204 * For a TCP-style SCTP socket, the states are defined as follows 205 * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to 206 * accept new associations, but it can initiate the creation of new ones. 207 * - A socket in SCTP_SS_LISTENING state indicates that it is willing to 208 * accept new associations, but cannot initiate the creation of new ones. 209 * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single 210 * association. 211 */ 212typedef enum { 213 SCTP_SS_CLOSED = TCP_CLOSE, 214 SCTP_SS_LISTENING = TCP_LISTEN, 215 SCTP_SS_ESTABLISHING = TCP_SYN_SENT, 216 SCTP_SS_ESTABLISHED = TCP_ESTABLISHED, 217 SCTP_SS_CLOSING = TCP_CLOSING, 218} sctp_sock_state_t; 219 220/* These functions map various type to printable names. */ 221const char *sctp_cname(const sctp_subtype_t); /* chunk types */ 222const char *sctp_oname(const sctp_subtype_t); /* other events */ 223const char *sctp_tname(const sctp_subtype_t); /* timeouts */ 224const char *sctp_pname(const sctp_subtype_t); /* primitives */ 225 226/* This is a table of printable names of sctp_state_t's. */ 227extern const char *const sctp_state_tbl[]; 228extern const char *const sctp_evttype_tbl[]; 229extern const char *const sctp_status_tbl[]; 230 231/* Maximum chunk length considering padding requirements. */ 232enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) }; 233 234/* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little 235 * harder (until reaching ESTABLISHED state). 236 */ 237enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 }; 238 239/* Guess at how big to make the TSN mapping array. 240 * We guarantee that we can handle at least this big a gap between the 241 * cumulative ACK and the highest TSN. In practice, we can often 242 * handle up to twice this value. 243 * 244 * NEVER make this more than 32767 (2^15-1). The Gap Ack Blocks in a 245 * SACK (see section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE 246 * must be less than 65535 (2^16 - 1), or we will have overflow 247 * problems creating SACK's. 248 */ 249#define SCTP_TSN_MAP_INITIAL BITS_PER_LONG 250#define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL 251#define SCTP_TSN_MAP_SIZE 4096 252 253/* We will not record more than this many duplicate TSNs between two 254 * SACKs. The minimum PMTU is 576. Remove all the headers and there 255 * is enough room for 131 duplicate reports. Round down to the 256 * nearest power of 2. 257 */ 258enum { SCTP_MIN_PMTU = 576 }; 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/* These return values describe the success or failure of a number of 308 * routines which form the lower interface to SCTP_outqueue. 309 */ 310typedef enum { 311 SCTP_XMIT_OK, 312 SCTP_XMIT_PMTU_FULL, 313 SCTP_XMIT_RWND_FULL, 314 SCTP_XMIT_DELAY, 315} sctp_xmit_t; 316 317/* These are the commands for manipulating transports. */ 318typedef enum { 319 SCTP_TRANSPORT_UP, 320 SCTP_TRANSPORT_DOWN, 321 SCTP_TRANSPORT_PF, 322} sctp_transport_cmd_t; 323 324/* These are the address scopes defined mainly for IPv4 addresses 325 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>. 326 * These scopes are hopefully generic enough to be used on scoping both 327 * IPv4 and IPv6 addresses in SCTP. 328 * At this point, the IPv6 scopes will be mapped to these internal scopes 329 * as much as possible. 330 */ 331typedef enum { 332 SCTP_SCOPE_GLOBAL, /* IPv4 global addresses */ 333 SCTP_SCOPE_PRIVATE, /* IPv4 private addresses */ 334 SCTP_SCOPE_LINK, /* IPv4 link local address */ 335 SCTP_SCOPE_LOOPBACK, /* IPv4 loopback address */ 336 SCTP_SCOPE_UNUSABLE, /* IPv4 unusable addresses */ 337} sctp_scope_t; 338 339typedef enum { 340 SCTP_SCOPE_POLICY_DISABLE, /* Disable IPv4 address scoping */ 341 SCTP_SCOPE_POLICY_ENABLE, /* Enable IPv4 address scoping */ 342 SCTP_SCOPE_POLICY_PRIVATE, /* Follow draft but allow IPv4 private addresses */ 343 SCTP_SCOPE_POLICY_LINK, /* Follow draft but allow IPv4 link local addresses */ 344} sctp_scope_policy_t; 345 346/* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>, 347 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24, 348 * 192.88.99.0/24. 349 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP 350 * addresses. 351 */ 352#define IS_IPV4_UNUSABLE_ADDRESS(a) \ 353 ((htonl(INADDR_BROADCAST) == a) || \ 354 ipv4_is_multicast(a) || \ 355 ipv4_is_zeronet(a) || \ 356 ipv4_is_test_198(a) || \ 357 ipv4_is_anycast_6to4(a)) 358 359/* Flags used for the bind address copy functions. */ 360#define SCTP_ADDR6_ALLOWED 0x00000001 /* IPv6 address is allowed by 361 local sock family */ 362#define SCTP_ADDR4_PEERSUPP 0x00000002 /* IPv4 address is supported by 363 peer */ 364#define SCTP_ADDR6_PEERSUPP 0x00000004 /* IPv6 address is supported by 365 peer */ 366 367/* Reasons to retransmit. */ 368typedef enum { 369 SCTP_RTXR_T3_RTX, 370 SCTP_RTXR_FAST_RTX, 371 SCTP_RTXR_PMTUD, 372 SCTP_RTXR_T1_RTX, 373} sctp_retransmit_reason_t; 374 375/* Reasons to lower cwnd. */ 376typedef enum { 377 SCTP_LOWER_CWND_T3_RTX, 378 SCTP_LOWER_CWND_FAST_RTX, 379 SCTP_LOWER_CWND_ECNE, 380 SCTP_LOWER_CWND_INACTIVE, 381} sctp_lower_cwnd_t; 382 383 384/* SCTP-AUTH Necessary constants */ 385 386/* SCTP-AUTH, Section 3.3 387 * 388 * The following Table 2 shows the currently defined values for HMAC 389 * identifiers. 390 * 391 * +-----------------+--------------------------+ 392 * | HMAC Identifier | Message Digest Algorithm | 393 * +-----------------+--------------------------+ 394 * | 0 | Reserved | 395 * | 1 | SHA-1 defined in [8] | 396 * | 2 | Reserved | 397 * | 3 | SHA-256 defined in [8] | 398 * +-----------------+--------------------------+ 399 */ 400enum { 401 SCTP_AUTH_HMAC_ID_RESERVED_0, 402 SCTP_AUTH_HMAC_ID_SHA1, 403 SCTP_AUTH_HMAC_ID_RESERVED_2, 404#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE) 405 SCTP_AUTH_HMAC_ID_SHA256, 406#endif 407 __SCTP_AUTH_HMAC_MAX 408}; 409 410#define SCTP_AUTH_HMAC_ID_MAX __SCTP_AUTH_HMAC_MAX - 1 411#define SCTP_AUTH_NUM_HMACS __SCTP_AUTH_HMAC_MAX 412#define SCTP_SHA1_SIG_SIZE 20 413#define SCTP_SHA256_SIG_SIZE 32 414 415/* SCTP-AUTH, Section 3.2 416 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks 417 * MUST NOT be listed in the CHUNKS parameter 418 */ 419#define SCTP_NUM_NOAUTH_CHUNKS 4 420#define SCTP_AUTH_MAX_CHUNKS (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS) 421 422/* SCTP-AUTH Section 6.1 423 * The RANDOM parameter MUST contain a 32 byte random number. 424 */ 425#define SCTP_AUTH_RANDOM_LENGTH 32 426 427#endif /* __sctp_constants_h__ */ 428