1 /* $NetBSD: tcp.h,v 1.11 1999/11/20 00:38:00 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 36 */ 37 38 #ifndef _NETINET_TCP_H_ 39 #define _NETINET_TCP_H_ 40 41 typedef u_int32_t tcp_seq; 42 /* 43 * TCP header. 44 * Per RFC 793, September, 1981. 45 */ 46 struct tcphdr { 47 u_int16_t th_sport; /* source port */ 48 u_int16_t th_dport; /* destination port */ 49 tcp_seq th_seq; /* sequence number */ 50 tcp_seq th_ack; /* acknowledgement number */ 51 #if BYTE_ORDER == LITTLE_ENDIAN 52 u_int8_t th_x2:4, /* (unused) */ 53 th_off:4; /* data offset */ 54 #endif 55 #if BYTE_ORDER == BIG_ENDIAN 56 u_int8_t th_off:4, /* data offset */ 57 th_x2:4; /* (unused) */ 58 #endif 59 u_int8_t th_flags; 60 #define TH_FIN 0x01 61 #define TH_SYN 0x02 62 #define TH_RST 0x04 63 #define TH_PUSH 0x08 64 #define TH_ACK 0x10 65 #define TH_URG 0x20 66 u_int16_t th_win; /* window */ 67 u_int16_t th_sum; /* checksum */ 68 u_int16_t th_urp; /* urgent pointer */ 69 } __attribute__((__packed__)); 70 71 #define TCPOPT_EOL 0 72 #define TCPOPT_NOP 1 73 #define TCPOPT_MAXSEG 2 74 #define TCPOLEN_MAXSEG 4 75 #define TCPOPT_WINDOW 3 76 #define TCPOLEN_WINDOW 3 77 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 78 #define TCPOLEN_SACK_PERMITTED 2 79 #define TCPOPT_SACK 5 /* Experimental */ 80 #define TCPOPT_TIMESTAMP 8 81 #define TCPOLEN_TIMESTAMP 10 82 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 83 84 #define TCPOPT_TSTAMP_HDR \ 85 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 86 87 /* 88 * Default maximum segment size for TCP. 89 * With an IP MSS of 576, this is 536, 90 * but 512 is probably more convenient. 91 * This should be defined as min(512, IP_MSS - sizeof (struct tcpiphdr)). 92 */ 93 #define TCP_MSS 512 94 95 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 96 97 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 98 99 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 100 101 /* 102 * User-settable options (used with setsockopt). 103 */ 104 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 105 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 106 107 #endif /* _NETINET_TCP_H_ */ 108