include/net/sctp/constants.h

   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 return values describe the success or failure of a number of
 290  * routines which form the lower interface to SCTP_outqueue.
 291  */
 292 enum sctp_xmit {
 293         SCTP_XMIT_OK,
 294         SCTP_XMIT_PMTU_FULL,
 295         SCTP_XMIT_RWND_FULL,
 296         SCTP_XMIT_DELAY,
 297 };
 298
 299 /* These are the commands for manipulating transports.  */
 300 enum sctp_transport_cmd {
 301         SCTP_TRANSPORT_UP,
 302         SCTP_TRANSPORT_DOWN,
 303         SCTP_TRANSPORT_PF,
 304 };
 305
 306 /* These are the address scopes defined mainly for IPv4 addresses
 307  * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 308  * These scopes are hopefully generic enough to be used on scoping both
 309  * IPv4 and IPv6 addresses in SCTP.
 310  * At this point, the IPv6 scopes will be mapped to these internal scopes
 311  * as much as possible.
 312  */
 313 enum sctp_scope {
 314         SCTP_SCOPE_GLOBAL,              /* IPv4 global addresses */
 315         SCTP_SCOPE_PRIVATE,             /* IPv4 private addresses */
 316         SCTP_SCOPE_LINK,                /* IPv4 link local address */
 317         SCTP_SCOPE_LOOPBACK,            /* IPv4 loopback address */
 318         SCTP_SCOPE_UNUSABLE,            /* IPv4 unusable addresses */
 319 };
 320
 321 enum {
 322         SCTP_SCOPE_POLICY_DISABLE,      /* Disable IPv4 address scoping */
 323         SCTP_SCOPE_POLICY_ENABLE,       /* Enable IPv4 address scoping */
 324         SCTP_SCOPE_POLICY_PRIVATE,      /* Follow draft but allow IPv4 private addresses */
 325         SCTP_SCOPE_POLICY_LINK,         /* Follow draft but allow IPv4 link local addresses */
 326 };
 327
 328 #define SCTP_SCOPE_POLICY_MAX   SCTP_SCOPE_POLICY_LINK
 329
 330 /* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
 331  * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
 332  * 192.88.99.0/24.
 333  * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
 334  * addresses.
 335  */
 336 #define IS_IPV4_UNUSABLE_ADDRESS(a)         \
 337         ((htonl(INADDR_BROADCAST) == a) ||  \
 338          ipv4_is_multicast(a) ||            \
 339          ipv4_is_zeronet(a) ||              \
 340          ipv4_is_test_198(a) ||             \
 341          ipv4_is_anycast_6to4(a))
 342
 343 /* Flags used for the bind address copy functions.  */
 344 #define SCTP_ADDR6_ALLOWED      0x00000001      /* IPv6 address is allowed by
 345                                                    local sock family */
 346 #define SCTP_ADDR4_PEERSUPP     0x00000002      /* IPv4 address is supported by
 347                                                    peer */
 348 #define SCTP_ADDR6_PEERSUPP     0x00000004      /* IPv6 address is supported by
 349                                                    peer */
 350
 351 /* Reasons to retransmit. */
 352 enum sctp_retransmit_reason {
 353         SCTP_RTXR_T3_RTX,
 354         SCTP_RTXR_FAST_RTX,
 355         SCTP_RTXR_PMTUD,
 356         SCTP_RTXR_T1_RTX,
 357 };
 358
 359 /* Reasons to lower cwnd. */
 360 enum sctp_lower_cwnd {
 361         SCTP_LOWER_CWND_T3_RTX,
 362         SCTP_LOWER_CWND_FAST_RTX,
 363         SCTP_LOWER_CWND_ECNE,
 364         SCTP_LOWER_CWND_INACTIVE,
 365 };
 366
 367
 368 /* SCTP-AUTH Necessary constants */
 369
 370 /* SCTP-AUTH, Section 3.3
 371  *
 372  *  The following Table 2 shows the currently defined values for HMAC
 373  *  identifiers.
 374  *
 375  *  +-----------------+--------------------------+
 376  *  | HMAC Identifier | Message Digest Algorithm |
 377  *  +-----------------+--------------------------+
 378  *  | 0               | Reserved                 |
 379  *  | 1               | SHA-1 defined in [8]     |
 380  *  | 2               | Reserved                 |
 381  *  | 3               | SHA-256 defined in [8]   |
 382  *  +-----------------+--------------------------+
 383  */
 384 enum {
 385         SCTP_AUTH_HMAC_ID_RESERVED_0,
 386         SCTP_AUTH_HMAC_ID_SHA1,
 387         SCTP_AUTH_HMAC_ID_RESERVED_2,
 388 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
 389         SCTP_AUTH_HMAC_ID_SHA256,
 390 #endif
 391         __SCTP_AUTH_HMAC_MAX
 392 };
 393
 394 #define SCTP_AUTH_HMAC_ID_MAX   __SCTP_AUTH_HMAC_MAX - 1
 395 #define SCTP_AUTH_NUM_HMACS     __SCTP_AUTH_HMAC_MAX
 396 #define SCTP_SHA1_SIG_SIZE 20
 397 #define SCTP_SHA256_SIG_SIZE 32
 398
 399 /*  SCTP-AUTH, Section 3.2
 400  *     The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
 401  *     MUST NOT be listed in the CHUNKS parameter
 402  */
 403 #define SCTP_NUM_NOAUTH_CHUNKS  4
 404 #define SCTP_AUTH_MAX_CHUNKS    (SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)
 405
 406 /* SCTP-AUTH Section 6.1
 407  * The RANDOM parameter MUST contain a 32 byte random number.
 408  */
 409 #define SCTP_AUTH_RANDOM_LENGTH 32
 410
 411 #endif /* __sctp_constants_h__ */