1 /* $NetBSD: tcp.h,v 1.28 2007/12/25 18:33:47 perry 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 32 */ 33 34 #ifndef _NETINET_TCP_H_ 35 #define _NETINET_TCP_H_ 36 37 #include <sys/featuretest.h> 38 39 #if defined(_NETBSD_SOURCE) 40 41 typedef u_int32_t tcp_seq; 42 /* 43 * TCP header. 44 * Per RFC 793, September, 1981. 45 * Updated by RFC 3168, September, 2001. 46 */ 47 struct tcphdr { 48 u_int16_t th_sport; /* source port */ 49 u_int16_t th_dport; /* destination port */ 50 tcp_seq th_seq; /* sequence number */ 51 tcp_seq th_ack; /* acknowledgement number */ 52 #if BYTE_ORDER == LITTLE_ENDIAN 53 /*LINTED non-portable bitfields*/ 54 u_int8_t th_x2:4, /* (unused) */ 55 th_off:4; /* data offset */ 56 #endif 57 #if BYTE_ORDER == BIG_ENDIAN 58 /*LINTED non-portable bitfields*/ 59 u_int8_t th_off:4, /* data offset */ 60 th_x2:4; /* (unused) */ 61 #endif 62 u_int8_t th_flags; 63 #define TH_FIN 0x01 64 #define TH_SYN 0x02 65 #define TH_RST 0x04 66 #define TH_PUSH 0x08 67 #define TH_ACK 0x10 68 #define TH_URG 0x20 69 #define TH_ECE 0x40 70 #define TH_CWR 0x80 71 u_int16_t th_win; /* window */ 72 u_int16_t th_sum; /* checksum */ 73 u_int16_t th_urp; /* urgent pointer */ 74 } __packed; 75 76 #define TCPOPT_EOL 0 77 #define TCPOPT_NOP 1 78 #define TCPOPT_MAXSEG 2 79 #define TCPOLEN_MAXSEG 4 80 #define TCPOPT_WINDOW 3 81 #define TCPOLEN_WINDOW 3 82 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 83 #define TCPOLEN_SACK_PERMITTED 2 84 #define TCPOPT_SACK 5 /* Experimental */ 85 #define TCPOPT_TIMESTAMP 8 86 #define TCPOLEN_TIMESTAMP 10 87 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 88 89 #define TCPOPT_TSTAMP_HDR \ 90 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 91 92 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 93 #define TCPOLEN_SIGNATURE 18 94 #define TCPOLEN_SIGLEN (TCPOLEN_SIGNATURE+2) /* padding */ 95 96 #define MAX_TCPOPTLEN 40 /* max # bytes that go in options */ 97 98 /* 99 * Default maximum segment size for TCP. 100 * This is defined by RFC 1112 Sec 4.2.2.6. 101 */ 102 #define TCP_MSS 536 103 104 #define TCP_MINMSS 216 105 106 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 107 108 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 109 110 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 111 112 #endif /* _NETBSD_SOURCE */ 113 114 /* 115 * User-settable options (used with setsockopt). 116 */ 117 #define TCP_NODELAY 1 /* don't delay send to coalesce packets */ 118 #define TCP_MAXSEG 2 /* set maximum segment size */ 119 #define TCP_KEEPIDLE 3 120 #ifdef notyet 121 #define TCP_NOPUSH 4 /* reserved for FreeBSD compat */ 122 #endif 123 #define TCP_KEEPINTVL 5 124 #define TCP_KEEPCNT 6 125 #define TCP_KEEPINIT 7 126 #ifdef notyet 127 #define TCP_NOOPT 8 /* reserved for FreeBSD compat */ 128 #endif 129 #define TCP_MD5SIG 0x10 /* use MD5 digests (RFC2385) */ 130 #define TCP_CONGCTL 0x20 /* selected congestion control */ 131 132 #endif /* !_NETINET_TCP_H_ */ 133