constants.h

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} sctp_sock_state_t;

/* These functions map various type to printable names.  */
const char *sctp_cname(const sctp_subtype_t);	/* chunk types */
const char *sctp_oname(const sctp_subtype_t);	/* other events */
const char *sctp_tname(const sctp_subtype_t);	/* timeouts */
const char *sctp_pname(const sctp_subtype_t);	/* primitives */

/* This is a table of printable names of sctp_state_t's.  */
extern const char *sctp_state_tbl[], *sctp_evttype_tbl[], *sctp_status_tbl[];

/* Maximum chunk length considering padding requirements. */
enum { SCTP_MAX_CHUNK_LEN = ((1<<16) - sizeof(__u32)) };

/* Encourage Cookie-Echo bundling by pre-fragmenting chunks a little
 * harder (until reaching ESTABLISHED state).
 */
enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 };

/* Guess at how big to make the TSN mapping array.
 * We guarantee that we can handle at least this big a gap between the
 * cumulative ACK and the highest TSN.  In practice, we can often
 * handle up to twice this value.
 *
 * NEVER make this more than 32767 (2^15-1).  The Gap Ack Blocks in a
 * SACK (see  section 3.3.4) are only 16 bits, so 2*SCTP_TSN_MAP_SIZE
 * must be less than 65535 (2^16 - 1), or we will have overflow
 * problems creating SACK's.
 */
#define SCTP_TSN_MAP_SIZE 2048
#define SCTP_TSN_MAX_GAP  65535

/* We will not record more than this many duplicate TSNs between two
 * SACKs.  The minimum PMTU is 576.  Remove all the headers and there
 * is enough room for 131 duplicate reports.  Round down to the
 * nearest power of 2.
 */
enum { SCTP_MIN_PMTU = 576 };
enum { SCTP_MAX_DUP_TSNS = 16 };
enum { SCTP_MAX_GABS = 16 };

/* Heartbeat interval - 30 secs */
#define SCTP_DEFAULT_TIMEOUT_HEARTBEAT	(30*1000)

/* Delayed sack timer - 200ms */
#define SCTP_DEFAULT_TIMEOUT_SACK	(200)

/* RTO.Initial              - 3  seconds
 * RTO.Min                  - 1  second
 * RTO.Max                  - 60 seconds
 * RTO.Alpha                - 1/8
 * RTO.Beta                 - 1/4
 */
#define SCTP_RTO_INITIAL	(3 * 1000)
#define SCTP_RTO_MIN		(1 * 1000)
#define SCTP_RTO_MAX		(60 * 1000)

#define SCTP_RTO_ALPHA          3   /* 1/8 when converted to right shifts. */
#define SCTP_RTO_BETA           2   /* 1/4 when converted to right shifts. */

/* Maximum number of new data packets that can be sent in a burst.  */
#define SCTP_DEFAULT_MAX_BURST		4

#define SCTP_CLOCK_GRANULARITY	1	/* 1 jiffy */

#define SCTP_DEF_MAX_INIT 6
#define SCTP_DEF_MAX_SEND 10

#define SCTP_DEFAULT_COOKIE_LIFE	(60 * 1000) /* 60 seconds */

#define SCTP_DEFAULT_MINWINDOW	1500	/* default minimum rwnd size */
#define SCTP_DEFAULT_MAXWINDOW	65535	/* default rwnd size */
#define SCTP_DEFAULT_MAXSEGMENT 1500	/* MTU size, this is the limit
                                         * to which we will raise the P-MTU.
					 */
#define SCTP_DEFAULT_MINSEGMENT 512	/* MTU size ... if no mtu disc */
#define SCTP_HOW_MANY_SECRETS 2		/* How many secrets I keep */
#define SCTP_HOW_LONG_COOKIE_LIVE 3600	/* How many seconds the current
					 * secret will live?
					 */
#define SCTP_SECRET_SIZE 32		/* Number of octets in a 256 bits. */

#define SCTP_SIGNATURE_SIZE 20	        /* size of a SLA-1 signature */

#define SCTP_COOKIE_MULTIPLE 32 /* Pad out our cookie to make our hash
				 * functions simpler to write.
				 */

#if defined (CONFIG_SCTP_HMAC_MD5)
#define SCTP_COOKIE_HMAC_ALG "hmac(md5)"
#elif defined (CONFIG_SCTP_HMAC_SHA1)
#define SCTP_COOKIE_HMAC_ALG "hmac(sha1)"
#else
#define SCTP_COOKIE_HMAC_ALG NULL
#endif

/* These return values describe the success or failure of a number of
 * routines which form the lower interface to SCTP_outqueue.
 */
typedef enum {
	SCTP_XMIT_OK,
	SCTP_XMIT_PMTU_FULL,
	SCTP_XMIT_RWND_FULL,
	SCTP_XMIT_NAGLE_DELAY,
} sctp_xmit_t;

/* These are the commands for manipulating transports.  */
typedef enum {
	SCTP_TRANSPORT_UP,
	SCTP_TRANSPORT_DOWN,
} sctp_transport_cmd_t;

/* These are the address scopes defined mainly for IPv4 addresses
 * based on draft of SCTP IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 * These scopes are hopefully generic enough to be used on scoping both
 * IPv4 and IPv6 addresses in SCTP.
 * At this point, the IPv6 scopes will be mapped to these internal scopes
 * as much as possible.
 */
typedef enum {
	SCTP_SCOPE_GLOBAL,		/* IPv4 global addresses */
	SCTP_SCOPE_PRIVATE,		/* IPv4 private addresses */
	SCTP_SCOPE_LINK,		/* IPv4 link local address */
	SCTP_SCOPE_LOOPBACK,		/* IPv4 loopback address */
	SCTP_SCOPE_UNUSABLE,		/* IPv4 unusable addresses */
} sctp_scope_t;

/* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
 * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
 * 192.88.99.0/24.
 * Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
 * addresses.
 */
#define IS_IPV4_UNUSABLE_ADDRESS(a) \
	((htonl(INADDR_BROADCAST) == *a) || \
	(MULTICAST(*a)) || \
	(((unsigned char *)(a))[0] == 0) || \
	((((unsigned char *)(a))[0] == 198) && \
	(((unsigned char *)(a))[1] == 18) && \
	(((unsigned char *)(a))[2] == 0)) || \
	((((unsigned char *)(a))[0] == 192) && \
	(((unsigned char *)(a))[1] == 88) && \
	(((unsigned char *)(a))[2] == 99)))

/* IPv4 Link-local addresses: 169.254.0.0/16.  */
#define IS_IPV4_LINK_ADDRESS(a) \
	((((unsigned char *)(a))[0] == 169) && \
	(((unsigned char *)(a))[1] == 254))

/* RFC 1918 "Address Allocation for Private Internets" defines the IPv4
 * private address space as the following:
 *
 * 10.0.0.0 - 10.255.255.255 (10/8 prefix)
 * 172.16.0.0.0 - 172.31.255.255 (172.16/12 prefix)
 * 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
 */
#define IS_IPV4_PRIVATE_ADDRESS(a) \
	((((unsigned char *)(a))[0] == 10) || \
	((((unsigned char *)(a))[0] == 172) && \
	(((unsigned char *)(a))[1] >= 16) && \
	(((unsigned char *)(a))[1] < 32)) || \
	((((unsigned char *)(a))[0] == 192) && \
	(((unsigned char *)(a))[1] == 168)))

/* Flags used for the bind address copy functions.  */
#define SCTP_ADDR6_ALLOWED	0x00000001	/* IPv6 address is allowed by
						   local sock family */
#define SCTP_ADDR4_PEERSUPP	0x00000002	/* IPv4 address is supported by
						   peer */
#define SCTP_ADDR6_PEERSUPP	0x00000004	/* IPv6 address is supported by
						   peer */

/* Reasons to retransmit. */
typedef enum {
	SCTP_RTXR_T3_RTX,
	SCTP_RTXR_FAST_RTX,
	SCTP_RTXR_PMTUD,
	SCTP_RTXR_T1_RTX,
} sctp_retransmit_reason_t;

/* Reasons to lower cwnd. */
typedef enum {
	SCTP_LOWER_CWND_T3_RTX,
	SCTP_LOWER_CWND_FAST_RTX,
	SCTP_LOWER_CWND_ECNE,
	SCTP_LOWER_CWND_INACTIVE,
} sctp_lower_cwnd_t;


/* SCTP-AUTH Necessary constants */

/* SCTP-AUTH, Section 3.3
 *
 *  The following Table 2 shows the currently defined values for HMAC
 *  identifiers.
 *
 *  +-----------------+--------------------------+
 *  | HMAC Identifier | Message Digest Algorithm |
 *  +-----------------+--------------------------+
 *  | 0               | Reserved                 |
 *  | 1               | SHA-1 defined in [8]     |
 *  | 2               | Reserved                 |
 *  | 3               | SHA-256 defined in [8]   |
 *  +-----------------+--------------------------+
 */
enum {
	SCTP_AUTH_HMAC_ID_RESERVED_0,
	SCTP_AUTH_HMAC_ID_SHA1,
	SCTP_AUTH_HMAC_ID_RESERVED_2,
#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
	SCTP_AUTH_HMAC_ID_SHA256,
#endif
	__SCTP_AUTH_HMAC_MAX
};

#define SCTP_AUTH_HMAC_ID_MAX	__SCTP_AUTH_HMAC_MAX - 1
#define SCTP_AUTH_NUM_HMACS 	__SCTP_AUTH_HMAC_MAX
#define SCTP_SHA1_SIG_SIZE 20
#define SCTP_SHA256_SIG_SIZE 32

/*  SCTP-AUTH, Section 3.2
 *     The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH chunks
 *     MUST NOT be listed in the CHUNKS parameter
 */
#define SCTP_NUM_NOAUTH_CHUNKS	4
#define SCTP_AUTH_MAX_CHUNKS	(SCTP_NUM_CHUNK_TYPES - SCTP_NUM_NOAUTH_CHUNKS)

/* SCTP-AUTH Section 6.1
 * The RANDOM parameter MUST contain a 32 byte random number.
 */
#define SCTP_AUTH_RANDOM_LENGTH 32

#endif /* __sctp_constants_h__ */