/* * Copyright (c) 1982, 1986 Regents of the University of California. * All rights reserved. * * Redistribution is only permitted until one year after the first shipment * of 4.4BSD by the Regents. Otherwise, redistribution and use in source and * binary forms are permitted provided that: (1) source distributions retain * this entire copyright notice and comment, and (2) distributions including * binaries display the following acknowledgement: This product includes * software developed by the University of California, Berkeley and its * contributors'' in the documentation or other materials provided with the * distribution and in all advertising materials mentioning features or use * of this software. Neither the name of the University nor the names of * its contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * @(#)tcp.h 7.7 (Berkeley) 6/28/90 */ 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 */ #if BYTE_ORDER == LITTLE_ENDIAN u_char th_x2:4, /* (unused) */ th_off:4; /* data offset */ #endif #if BYTE_ORDER == BIG_ENDIAN u_char th_off:4, /* data offset */ th_x2:4; /* (unused) */ #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. * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). */ #define TCP_MSS 512 #define TCP_MAXWIN 65535 /* largest value for window */ /* * 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 */