1*9992Ssam /* tcp.h 1.23 82/12/28 */ 24573Swnj 35085Swnj typedef u_long tcp_seq; 44573Swnj /* 54899Swnj * TCP header. 64924Swnj * Per RFC 793, September, 1981. 74573Swnj */ 84899Swnj struct tcphdr { 94899Swnj u_short th_sport; /* source port */ 104899Swnj u_short th_dport; /* destination port */ 115085Swnj tcp_seq th_seq; /* sequence number */ 125085Swnj tcp_seq th_ack; /* acknowledgement number */ 13*9992Ssam #ifdef vax 14*9992Ssam u_char th_x2:4, /* (unused) */ 154899Swnj th_off:4; /* data offset */ 16*9992Ssam #endif 17*9992Ssam #ifdef sun 18*9992Ssam u_char th_off:4, /* data offset */ 19*9992Ssam th_x2:4; /* (unused) */ 20*9992Ssam #endif 214575Swnj u_char th_flags; 225065Swnj #define TH_FIN 0x01 235065Swnj #define TH_SYN 0x02 245065Swnj #define TH_RST 0x04 255065Swnj #define TH_PUSH 0x08 265065Swnj #define TH_ACK 0x10 275065Swnj #define TH_URG 0x20 284899Swnj u_short th_win; /* window */ 294899Swnj u_short th_sum; /* checksum */ 304899Swnj u_short th_urp; /* urgent pointer */ 314499Swnj }; 325440Swnj 335440Swnj #define TCPOPT_EOL 0 345440Swnj #define TCPOPT_NOP 1 355440Swnj #define TCPOPT_MAXSEG 2 36