/* * Copyright (c) 1982, 1986 Regents of the University of California. * All rights reserved. The Berkeley software License Agreement * specifies the terms and conditions for redistribution. * * @(#)tcp.h 7.1 (Berkeley) 6/5/86 */ /* * RCS Info * $Header: tcp.h,v 3.1 86/10/22 13:35:01 tadl Exp $ * $Locker: $ */ typedef u_long tcp_seq; /* * TCP header. * Per RFC 793, September, 1981. */ struct tcphdr { u_short th_sport; /* source port */ u_short th_dport; /* destination port */ tcp_seq th_seq; /* sequence number */ tcp_seq th_ack; /* acknowledgement number */ #ifdef vax u_char th_x2:4, /* (unused) */ th_off:4; /* data offset */ #endif u_char th_flags; #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_PUSH 0x08 #define TH_ACK 0x10 #define TH_URG 0x20 u_short th_win; /* window */ u_short th_sum; /* checksum */ u_short th_urp; /* urgent pointer */ }; #define TCPOPT_EOL 0 #define TCPOPT_NOP 1 #define TCPOPT_MAXSEG 2 /* * Default maximum segment size for TCP. * With an IP MSS of 576, this is 536, * but 512 is probably more convenient. */ #ifdef lint #define TCP_MSS 536 #else #define TCP_MSS MIN(512, IP_MSS - sizeof (struct tcpiphdr)) #endif /* * User-settable options (used with setsockopt). */ #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ #define TCP_MAXSEG 0x02 /* set maximum segment size */