include/net/sctp/constants.h

   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__ */