123187Smckusick /* 2*63218Sbostic * Copyright (c) 1982, 1986, 1993 3*63218Sbostic * The Regents of the University of California. All rights reserved. 423187Smckusick * 544483Sbostic * %sccs.include.redist.c% 632787Sbostic * 7*63218Sbostic * @(#)tcp.h 8.1 (Berkeley) 06/10/93 823187Smckusick */ 94573Swnj 105085Swnj typedef u_long tcp_seq; 114573Swnj /* 124899Swnj * TCP header. 134924Swnj * Per RFC 793, September, 1981. 144573Swnj */ 154899Swnj struct tcphdr { 164899Swnj u_short th_sport; /* source port */ 174899Swnj u_short th_dport; /* destination port */ 185085Swnj tcp_seq th_seq; /* sequence number */ 195085Swnj tcp_seq th_ack; /* acknowledgement number */ 2044373Skarels #if BYTE_ORDER == LITTLE_ENDIAN 219992Ssam u_char th_x2:4, /* (unused) */ 224899Swnj th_off:4; /* data offset */ 239992Ssam #endif 2444373Skarels #if BYTE_ORDER == BIG_ENDIAN 2529923Skarels u_char th_off:4, /* data offset */ 2629923Skarels th_x2:4; /* (unused) */ 2729923Skarels #endif 284575Swnj u_char th_flags; 295065Swnj #define TH_FIN 0x01 305065Swnj #define TH_SYN 0x02 315065Swnj #define TH_RST 0x04 325065Swnj #define TH_PUSH 0x08 335065Swnj #define TH_ACK 0x10 345065Swnj #define TH_URG 0x20 354899Swnj u_short th_win; /* window */ 364899Swnj u_short th_sum; /* checksum */ 374899Swnj u_short th_urp; /* urgent pointer */ 384499Swnj }; 395440Swnj 4057433Sandrew #define TCPOPT_EOL 0 4157433Sandrew #define TCPOPT_NOP 1 4257433Sandrew #define TCPOPT_MAXSEG 2 4357433Sandrew #define TCPOLEN_MAXSEG 4 4457433Sandrew #define TCPOPT_WINDOW 3 4557433Sandrew #define TCPOLEN_WINDOW 3 4657433Sandrew #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 4757433Sandrew #define TCPOLEN_SACK_PERMITTED 2 4857433Sandrew #define TCPOPT_SACK 5 /* Experimental */ 4957433Sandrew #define TCPOPT_TIMESTAMP 8 5057433Sandrew #define TCPOLEN_TIMESTAMP 10 5157433Sandrew #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 5217316Skarels 5357433Sandrew #define TCPOPT_TSTAMP_HDR \ 5457433Sandrew (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 5557433Sandrew 5617316Skarels /* 5726259Skarels * Default maximum segment size for TCP. 5826259Skarels * With an IP MSS of 576, this is 536, 5926259Skarels * but 512 is probably more convenient. 6044373Skarels * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 6117316Skarels */ 6244373Skarels #define TCP_MSS 512 6325895Skarels 6457433Sandrew #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 6544373Skarels 6657433Sandrew #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 6757433Sandrew 6825895Skarels /* 6925895Skarels * User-settable options (used with setsockopt). 7025895Skarels */ 7125895Skarels #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 7225895Skarels #define TCP_MAXSEG 0x02 /* set maximum segment size */ 73