123187Smckusick /* 229147Smckusick * Copyright (c) 1982, 1986 Regents of the University of California. 323187Smckusick * All rights reserved. The Berkeley software License Agreement 423187Smckusick * specifies the terms and conditions for redistribution. 523187Smckusick * 6*29923Skarels * @(#)tcp.h 7.2 (Berkeley) 10/28/86 723187Smckusick */ 84573Swnj 95085Swnj typedef u_long tcp_seq; 104573Swnj /* 114899Swnj * TCP header. 124924Swnj * Per RFC 793, September, 1981. 134573Swnj */ 144899Swnj struct tcphdr { 154899Swnj u_short th_sport; /* source port */ 164899Swnj u_short th_dport; /* destination port */ 175085Swnj tcp_seq th_seq; /* sequence number */ 185085Swnj tcp_seq th_ack; /* acknowledgement number */ 19*29923Skarels #if ENDIAN == LITTLE 209992Ssam u_char th_x2:4, /* (unused) */ 214899Swnj th_off:4; /* data offset */ 229992Ssam #endif 23*29923Skarels #if ENDIAN == BIG 24*29923Skarels u_char th_off:4, /* data offset */ 25*29923Skarels th_x2:4; /* (unused) */ 26*29923Skarels #endif 274575Swnj u_char th_flags; 285065Swnj #define TH_FIN 0x01 295065Swnj #define TH_SYN 0x02 305065Swnj #define TH_RST 0x04 315065Swnj #define TH_PUSH 0x08 325065Swnj #define TH_ACK 0x10 335065Swnj #define TH_URG 0x20 344899Swnj u_short th_win; /* window */ 354899Swnj u_short th_sum; /* checksum */ 364899Swnj u_short th_urp; /* urgent pointer */ 374499Swnj }; 385440Swnj 395440Swnj #define TCPOPT_EOL 0 405440Swnj #define TCPOPT_NOP 1 415440Swnj #define TCPOPT_MAXSEG 2 4217316Skarels 4317316Skarels /* 4426259Skarels * Default maximum segment size for TCP. 4526259Skarels * With an IP MSS of 576, this is 536, 4626259Skarels * but 512 is probably more convenient. 4717316Skarels */ 4826259Skarels #ifdef lint 4926259Skarels #define TCP_MSS 536 5026259Skarels #else 5117316Skarels #define TCP_MSS MIN(512, IP_MSS - sizeof (struct tcpiphdr)) 5226259Skarels #endif 5325895Skarels 5425895Skarels /* 5525895Skarels * User-settable options (used with setsockopt). 5625895Skarels */ 5725895Skarels #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 5825895Skarels #define TCP_MAXSEG 0x02 /* set maximum segment size */ 59