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_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.  */
  71 typedef 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
  84 typedef 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
 100 typedef 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.  */
 109 typedef 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
 127 typedef 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) \
 135 static inline sctp_subtype_t    \
 136 SCTP_ST_## _name (_type _arg)           \
 137 { sctp_subtype_t _retval; _retval._elt = _arg; return _retval; }
 138
 139 SCTP_SUBTYPE_CONSTRUCTOR(CHUNK,         sctp_cid_t,             chunk)
 140 SCTP_SUBTYPE_CONSTRUCTOR(TIMEOUT,       sctp_event_timeout_t,   timeout)
 141 SCTP_SUBTYPE_CONSTRUCTOR(OTHER,         sctp_event_other_t,     other)
 142 SCTP_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 */
 153 typedef 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 */
 180 typedef 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  */
 212 typedef 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.  */
 221 const char *sctp_cname(const sctp_subtype_t);   /* chunk types */
 222 const char *sctp_oname(const sctp_subtype_t);   /* other events */
 223 const char *sctp_tname(const sctp_subtype_t);   /* timeouts */
 224 const char *sctp_pname(const sctp_subtype_t);   /* primitives */
 225
 226 /* This is a table of printable names of sctp_state_t's.  */
 227 extern const char *const sctp_state_tbl[];
 228 extern const char *const sctp_evttype_tbl[];
 229 extern const char *const sctp_status_tbl[];
 230
 231 /* Maximum chunk length considering padding requirements. */
 232 enum { 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  */
 237 enum { 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  */
 258 enum { SCTP_MIN_PMTU = 576 };
 259 enum { SCTP_MAX_DUP_TSNS = 16 };
 260 enum { 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  */
 310 typedef 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.  */
 318 typedef 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  */
 331 typedef 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
 339 typedef 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. */
 368 typedef 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. */
 376 typedef 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  */
 400 enum {
 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__ */