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, write to
  23  * the Free Software Foundation, 59 Temple Place - Suite 330,
  24  * Boston, MA 02111-1307, USA.
  25  *
  26  * Please send any bug reports or fixes you make to the
  27  * email address(es):
  28  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  29  *
  30  * Or submit a bug report through the following website:
  31  *    http://www.sf.net/projects/lksctp
  32  *
  33  * Written or modified by:
  34  *   La Monte H.P. Yarroll <piggy@acm.org>
  35  *   Karl Knutson          <karl@athena.chicago.il.us>
  36  *   Randall Stewart       <randall@stewart.chicago.il.us>
  37  *   Ken Morneau           <kmorneau@cisco.com>
  38  *   Qiaobing Xie          <qxie1@motorola.com>
  39  *   Xingang Guo           <xingang.guo@intel.com>
  40  *   Sridhar Samudrala     <samudrala@us.ibm.com>
  41  *   Daisy Chang           <daisyc@us.ibm.com>
  42  *
  43  * Any bugs reported given to us we will try to fix... any fixes shared will
  44  * be incorporated into the next SCTP release.
  45  */
  46
  47 #ifndef __sctp_constants_h__
  48 #define __sctp_constants_h__
  49
  50 #include <linux/sctp.h>
  51 #include <linux/ipv6.h> /* For ipv6hdr. */
  52 #include <net/sctp/user.h>
  53 #include <net/tcp_states.h>  /* For TCP states used in sctp_sock_state_t */
  54
  55 /* Value used for stream negotiation. */
  56 enum { SCTP_MAX_STREAM = 0xffff };
  57 enum { SCTP_DEFAULT_OUTSTREAMS = 10 };
  58 enum { SCTP_DEFAULT_INSTREAMS = SCTP_MAX_STREAM };
  59
  60 /* Since CIDs are sparse, we need all four of the following
  61  * symbols.  CIDs are dense through SCTP_CID_BASE_MAX.
  62  */
  63 #define SCTP_CID_BASE_MAX               SCTP_CID_SHUTDOWN_COMPLETE
  64
  65 #define SCTP_NUM_BASE_CHUNK_TYPES       (SCTP_CID_BASE_MAX + 1)
  66
  67 #define SCTP_NUM_ADDIP_CHUNK_TYPES      2
  68
  69 #define SCTP_NUM_PRSCTP_CHUNK_TYPES     1
  70
  71 #define SCTP_NUM_AUTH_CHUNK_TYPES       1
  72
  73 #define SCTP_NUM_CHUNK_TYPES            (SCTP_NUM_BASE_CHUNK_TYPES + \
  74                                          SCTP_NUM_ADDIP_CHUNK_TYPES +\
  75                                          SCTP_NUM_PRSCTP_CHUNK_TYPES +\
  76                                          SCTP_NUM_AUTH_CHUNK_TYPES)
  77
  78 /* These are the different flavours of event.  */
  79 typedef enum {
  80
  81         SCTP_EVENT_T_CHUNK = 1,
  82         SCTP_EVENT_T_TIMEOUT,
  83         SCTP_EVENT_T_OTHER,
  84         SCTP_EVENT_T_PRIMITIVE
  85
  86 } sctp_event_t;
  87
  88 /* As a convenience for the state machine, we append SCTP_EVENT_* and
  89  * SCTP_ULP_* to the list of possible chunks.
  90  */
  91
  92 typedef enum {
  93         SCTP_EVENT_TIMEOUT_NONE = 0,
  94         SCTP_EVENT_TIMEOUT_T1_COOKIE,
  95         SCTP_EVENT_TIMEOUT_T1_INIT,
  96         SCTP_EVENT_TIMEOUT_T2_SHUTDOWN,
  97         SCTP_EVENT_TIMEOUT_T3_RTX,
  98         SCTP_EVENT_TIMEOUT_T4_RTO,
  99         SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
 100         SCTP_EVENT_TIMEOUT_HEARTBEAT,
 101         SCTP_EVENT_TIMEOUT_SACK,
 102         SCTP_EVENT_TIMEOUT_AUTOCLOSE,
 103 } sctp_event_timeout_t;
 104
 105 #define SCTP_EVENT_TIMEOUT_MAX          SCTP_EVENT_TIMEOUT_AUTOCLOSE
 106 #define SCTP_NUM_TIMEOUT_TYPES          (SCTP_EVENT_TIMEOUT_MAX + 1)
 107
 108 typedef enum {
 109         SCTP_EVENT_NO_PENDING_TSN = 0,
 110         SCTP_EVENT_ICMP_PROTO_UNREACH,
 111 } sctp_event_other_t;
 112
 113 #define SCTP_EVENT_OTHER_MAX            SCTP_EVENT_ICMP_PROTO_UNREACH
 114 #define SCTP_NUM_OTHER_TYPES            (SCTP_EVENT_OTHER_MAX + 1)
 115
 116 /* These are primitive requests from the ULP.  */
 117 typedef enum {
 118         SCTP_PRIMITIVE_ASSOCIATE = 0,
 119         SCTP_PRIMITIVE_SHUTDOWN,
 120         SCTP_PRIMITIVE_ABORT,
 121         SCTP_PRIMITIVE_SEND,
 122         SCTP_PRIMITIVE_REQUESTHEARTBEAT,
 123         SCTP_PRIMITIVE_ASCONF,
 124 } sctp_event_primitive_t;
 125
 126 #define SCTP_EVENT_PRIMITIVE_MAX        SCTP_PRIMITIVE_ASCONF
 127 #define SCTP_NUM_PRIMITIVE_TYPES        (SCTP_EVENT_PRIMITIVE_MAX + 1)
 128
 129 /* We define here a utility type for manipulating subtypes.
 130  * The subtype constructors all work like this:
 131  *
 132  *      sctp_subtype_t foo = SCTP_ST_CHUNK(SCTP_CID_INIT);
 133  */
 134
 135 typedef union {
 136         sctp_cid_t chunk;
 137         sctp_event_timeout_t timeout;
 138         sctp_event_other_t other;
 139         sctp_event_primitive_t primitive;
 140 } sctp_subtype_t;
 141
 142 #define SCTP_SUBTYPE_CONSTRUCTOR(_name, _type, _elt) \
 143 static inline sctp_subtype_t    \
 144 SCTP_ST_## _name (_type _arg)           \
 145 { sctp_subtype_t _retval; _retval._elt = _arg; return _retval; }
 146
 147 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK,         sctp_cid_t,             chunk)
 148 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT,       sctp_event_timeout_t,   timeout)
 149 SCTP_SUBTYPE_CONSTRUCTOR(OTHER,         sctp_event_other_t,     other)
 150 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE,     sctp_event_primitive_t, primitive)
 151
 152
 153 #define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA)
 154
 155 /* Calculate the actual data size in a data chunk */
 156 #define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\
 157                                 - (unsigned long)(c->chunk_hdr)\
 158                                 - sizeof(sctp_data_chunk_t)))
 159
 160 /* Internal error codes */
 161 typedef enum {
 162
 163         SCTP_IERROR_NO_ERROR            = 0,
 164         SCTP_IERROR_BASE                = 1000,
 165         SCTP_IERROR_NO_COOKIE,
 166         SCTP_IERROR_BAD_SIG,
 167         SCTP_IERROR_STALE_COOKIE,
 168         SCTP_IERROR_NOMEM,
 169         SCTP_IERROR_MALFORMED,
 170         SCTP_IERROR_BAD_TAG,
 171         SCTP_IERROR_BIG_GAP,
 172         SCTP_IERROR_DUP_TSN,
 173         SCTP_IERROR_HIGH_TSN,
 174         SCTP_IERROR_IGNORE_TSN,
 175         SCTP_IERROR_NO_DATA,
 176         SCTP_IERROR_BAD_STREAM,
 177         SCTP_IERROR_BAD_PORTS,
 178         SCTP_IERROR_AUTH_BAD_HMAC,
 179         SCTP_IERROR_AUTH_BAD_KEYID,
 180         SCTP_IERROR_PROTO_VIOLATION,
 181         SCTP_IERROR_ERROR,
 182         SCTP_IERROR_ABORT,
 183 } sctp_ierror_t;
 184
 185
 186
 187 /* SCTP state defines for internal state machine */
 188 typedef enum {
 189
 190         SCTP_STATE_CLOSED               = 0,
 191         SCTP_STATE_COOKIE_WAIT          = 1,
 192         SCTP_STATE_COOKIE_ECHOED        = 2,
 193         SCTP_STATE_ESTABLISHED          = 3,
 194         SCTP_STATE_SHUTDOWN_PENDING     = 4,
 195         SCTP_STATE_SHUTDOWN_SENT        = 5,
 196         SCTP_STATE_SHUTDOWN_RECEIVED    = 6,
 197         SCTP_STATE_SHUTDOWN_ACK_SENT    = 7,
 198
 199 } sctp_state_t;
 200
 201 #define SCTP_STATE_MAX                  SCTP_STATE_SHUTDOWN_ACK_SENT
 202 #define SCTP_STATE_NUM_STATES           (SCTP_STATE_MAX + 1)
 203
 204 /* These are values for sk->state.
 205  * For a UDP-style SCTP socket, the states are defined as follows
 206  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
 207  *   accept new associations, but it can initiate the creation of new ones.
 208  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
 209  *   accept new  associations and can initiate the creation of new ones.
 210  * - A socket in SCTP_SS_ESTABLISHED state indicates that it is a peeled off
 211  *   socket with one association.
 212  * For a TCP-style SCTP socket, the states are defined as follows
 213  * - A socket in SCTP_SS_CLOSED state indicates that it is not willing to
 214  *   accept new associations, but it can initiate the creation of new ones.
 215  * - A socket in SCTP_SS_LISTENING state indicates that it is willing to
 216  *   accept new associations, but cannot initiate the creation of new ones.
 217  * - A socket in SCTP_SS_ESTABLISHED state indicates that it has a single
 218  *   association.
 219  */
 220 typedef enum {
 221         SCTP_SS_CLOSED         = TCP_CLOSE,
 222         SCTP_SS_LISTENING      = TCP_LISTEN,
 223         SCTP_SS_ESTABLISHING   = TCP_SYN_SENT,
 224         SCTP_SS_ESTABLISHED    = TCP_ESTABLISHED,
 225         SCTP_SS_CLOSING        = TCP_CLOSING,
 226 } sctp_sock_state_t;
 227
 228 /* These functions map various type to printable names.  */
 229 const char *sctp_cname(const sctp_subtype_t);   /* chunk types */
 230 const char *sctp_oname(const sctp_subtype_t);   /* other events */
 231 const char *sctp_tname(const sctp_subtype_t);   /* timeouts */
 232 const char *sctp_pname(const sctp_subtype_t);   /* primitives */
 233
 234 /* This is a table of printable names of sctp_state_t's.  */
 235 extern const char *const sctp_state_tbl[];
 236 extern const char *const sctp_evttype_tbl[];
 237 extern const char *const sctp_status_tbl[];
 238
 239 /* Maximum chunk length considering padding requirements. */
 240 enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };
 241
 242 /* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
 243  * harder (until reaching ESTABLISHED state).
 244  */
 245 enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };
 246
 247 /* Guess at how big to make the TSN mapping array.
 248  * We guarantee that we can handle at least this big a gap between the
 249  * cumulative ACK and the highest TSN.  In practice, we can often
 250  * handle up to twice this value.
 251  *
 252  * NEVER make this more than 32767 (2^15-1).  The Gap Ack Blocks in a
 253  * SACK (see  section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
 254  * must be less than 65535 (2^16 - 1), or we will have overflow
 255  * problems creating SACK's.
 256  */
 257 #define SCTP_TSN_MAP_INITIAL BITS_PER_LONG
 258 #define SCTP_TSN_MAP_INCREMENT SCTP_TSN_MAP_INITIAL
 259 #define SCTP_TSN_MAP_SIZE 4096
 260
 261 /* We will not record more than this many duplicate TSNs between two
 262  * SACKs.  The minimum PMTU is 576.  Remove all the headers and there
 263  * is enough room for 131 duplicate reports.  Round down to the
 264  * nearest power of 2.
 265  */
 266 enum { SCTP_MIN_PMTU = 576 };
 267 enum { SCTP_MAX_DUP_TSNS = 16 };
 268 enum { SCTP_MAX_GABS = 16 };
 269
 270 /* Heartbeat interval - 30 secs */
 271 #define SCTP_DEFAULT_TIMEOUT_HEARTBEAT  (30*1000)
 272
 273 /* Delayed sack timer - 200ms */
 274 #define SCTP_DEFAULT_TIMEOUT_SACK       (200)
 275
 276 /* RTO.Initial              - 3  seconds
 277  * RTO.Min                  - 1  second
 278  * RTO.Max                  - 60 seconds
 279  * RTO.Alpha                - 1/8
 280  * RTO.Beta                 - 1/4
 281  */
 282 #define SCTP_RTO_INITIAL        (3 * 1000)
 283 #define SCTP_RTO_MIN            (1 * 1000)
 284 #define SCTP_RTO_MAX            (60 * 1000)
 285
 286 #define SCTP_RTO_ALPHA          3   /* 1/8 when converted to right shifts. */
 287 #define SCTP_RTO_BETA           2   /* 1/4 when converted to right shifts. */
 288
 289 /* Maximum number of new data packets that can be sent in a burst.  */
 290 #define SCTP_DEFAULT_MAX_BURST          4
 291
 292 #define SCTP_CLOCK_GRANULARITY  1       /* 1 jiffy */
 293
 294 #define SCTP_DEFAULT_COOKIE_LIFE        (60 * 1000) /* 60 seconds */
 295
 296 #define SCTP_DEFAULT_MINWINDOW  1500    /* default minimum rwnd size */
 297 #define SCTP_DEFAULT_MAXWINDOW  65535   /* default rwnd size */
 298 #define SCTP_DEFAULT_RWND_SHIFT  4      /* by default, update on 1/16 of
 299                                          * rcvbuf, which is 1/8 of initial
 300                                          * window
 301                                          */
 302 #define SCTP_DEFAULT_MAXSEGMENT 1500    /* MTU size, this is the limit
 303                                          * to which we will raise the P-MTU.
 304                                          */
 305 #define SCTP_DEFAULT_MINSEGMENT 512     /* MTU size ... if no mtu disc */
 306 #define SCTP_HOW_MANY_SECRETS 2         /* How many secrets I keep */
 307 #define SCTP_SECRET_SIZE 32             /* Number of octets in a 256 bits. */
 308
 309 #define SCTP_SIGNATURE_SIZE 20          /* size of a SLA-1 signature */
 310
 311 #define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
 312                                  * functions simpler to write.
 313                                  */
 314
 315 #if defined (CONFIG_SCTP_HMAC_MD5)
 316 #define SCTP_COOKIE_HMAC_ALG "hmac(md5)"
 317 #elif defined (CONFIG_SCTP_HMAC_SHA1)
 318 #define SCTP_COOKIE_HMAC_ALG "hmac(sha1)"
 319 #else
 320 #define SCTP_COOKIE_HMAC_ALG NULL
 321 #endif
 322
 323 /* These return values describe the success or failure of a number of
 324  * routines which form the lower interface to SCTP_outqueue.
 325  */
 326 typedef enum {
 327         SCTP_XMIT_OK,
 328         SCTP_XMIT_PMTU_FULL,
 329         SCTP_XMIT_RWND_FULL,
 330         SCTP_XMIT_NAGLE_DELAY,
 331 } sctp_xmit_t;
 332
 333 /* These are the commands for manipulating transports.  */
 334 typedef enum {
 335         SCTP_TRANSPORT_UP,
 336         SCTP_TRANSPORT_DOWN,
 337         SCTP_TRANSPORT_PF,
 338 } sctp_transport_cmd_t;
 339
 340 /* These are the address scopes defined mainly for IPv4 addresses
 341  * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 342  * These scopes are hopefully generic enough to be used on scoping both
 343  * IPv4 and IPv6 addresses in SCTP.
 344  * At this point, the IPv6 scopes will be mapped to these internal scopes
 345  * as much as possible.
 346  */
 347 typedef enum {
 348         SCTP_SCOPE_GLOBAL,              /* IPv4 global addresses */
 349         SCTP_SCOPE_PRIVATE,             /* IPv4 private addresses */
 350         SCTP_SCOPE_LINK,                /* IPv4 link local address */
 351         SCTP_SCOPE_LOOPBACK,            /* IPv4 loopback address */
 352         SCTP_SCOPE_UNUSABLE,            /* IPv4 unusable addresses */
 353 } sctp_scope_t;
 354
 355 typedef enum {
 356         SCTP_SCOPE_POLICY_DISABLE,      /* Disable IPv4 address scoping */
 357         SCTP_SCOPE_POLICY_ENABLE,       /* Enable IPv4 address scoping */
 358         SCTP_SCOPE_POLICY_PRIVATE,      /* Follow draft but allow IPv4 private addresses */
 359         SCTP_SCOPE_POLICY_LINK,         /* Follow draft but allow IPv4 link local addresses */
 360 } sctp_scope_policy_t;
 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, 198.18.0.0/24,
 364  * 192.88.99.0/24.
 365  * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
 366  * addresses.
 367  */
 368 #define IS_IPV4_UNUSABLE_ADDRESS(a)         \
 369         ((htonl(INADDR_BROADCAST) == a) ||  \
 370          ipv4_is_multicast(a) ||            \
 371          ipv4_is_zeronet(a) ||              \
 372          ipv4_is_test_198(a) ||             \
 373          ipv4_is_anycast_6to4(a))
 374
 375 /* Flags used for the bind address copy functions.  */
 376 #define SCTP_ADDR6_ALLOWED      0x00000001      /* IPv6 address is allowed by
 377                                                    local sock family */
 378 #define SCTP_ADDR4_PEERSUPP     0x00000002      /* IPv4 address is supported by
 379                                                    peer */
 380 #define SCTP_ADDR6_PEERSUPP     0x00000004      /* IPv6 address is supported by
 381                                                    peer */
 382
 383 /* Reasons to retransmit. */
 384 typedef enum {
 385         SCTP_RTXR_T3_RTX,
 386         SCTP_RTXR_FAST_RTX,
 387         SCTP_RTXR_PMTUD,
 388         SCTP_RTXR_T1_RTX,
 389 } sctp_retransmit_reason_t;
 390
 391 /* Reasons to lower cwnd. */
 392 typedef enum {
 393         SCTP_LOWER_CWND_T3_RTX,
 394         SCTP_LOWER_CWND_FAST_RTX,
 395         SCTP_LOWER_CWND_ECNE,
 396         SCTP_LOWER_CWND_INACTIVE,
 397 } sctp_lower_cwnd_t;
 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  */
 416 enum {
 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 #endif /* __sctp_constants_h__ */