1 /** $MirOS: src/sys/netinet/tcp.h,v 1.2 2006/01/31 10:09:43 tg Exp $ */ 2 /* $OpenBSD: tcp.h,v 1.15 2004/02/10 10:30:24 markus Exp $ */ 3 /* $NetBSD: tcp.h,v 1.8 1995/04/17 05:32:58 cgd Exp $ */ 4 5 /* 6 * Copyright (c) 1982, 1986, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 34 */ 35 36 /* 37 * improvements 2006 by Marco Munari <mar.develops allerta.it> 38 */ 39 40 #ifndef _NETINET_TCP_H_ 41 #define _NETINET_TCP_H_ 42 43 typedef u_int32_t tcp_seq; 44 45 /* 46 * TCP header. 47 * Per RFC 793, September, 1981. 48 */ 49 struct tcphdr { 50 u_int16_t th_sport; /* source port */ 51 u_int16_t th_dport; /* destination port */ 52 tcp_seq th_seq; /* sequence number */ 53 tcp_seq th_ack; /* acknowledgement number */ 54 #if BYTE_ORDER == LITTLE_ENDIAN 55 u_int8_t th_x2:4, /* (unused) */ 56 th_off:4; /* data offset */ 57 #endif 58 #if BYTE_ORDER == BIG_ENDIAN 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 #define TH_BITS "\20\2SYN\5ACK\1FIN\3RST\4PUSH\6URG\7ECE\10CWR" 72 u_int16_t th_win; /* window */ 73 u_int16_t th_sum; /* checksum */ 74 u_int16_t th_urp; /* urgent pointer */ 75 }; 76 #define th_reseqlen th_urp /* TCP data length for 77 resequencing/reassembly */ 78 79 #define TCPOPT_EOL 0 80 #define TCPOPT_NOP 1 81 #define TCPOPT_MAXSEG 2 82 #define TCPOLEN_MAXSEG 4 83 #define TCPOPT_WINDOW 3 84 #define TCPOLEN_WINDOW 3 85 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 86 #define TCPOLEN_SACK_PERMITTED 2 87 #define TCPOPT_SACK 5 /* Experimental */ 88 #define TCPOLEN_SACK 8 /* 2*sizeof(tcp_seq) */ 89 #define TCPOPT_TIMESTAMP 8 90 #define TCPOLEN_TIMESTAMP 10 91 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 92 #define TCPOPT_SIGNATURE 19 93 #define TCPOLEN_SIGNATURE 18 94 #define TCPOLEN_SIGLEN (TCPOLEN_SIGNATURE+2) /* padding */ 95 96 #define MAX_TCPOPTLEN 40 /* Absolute maximum TCP options len */ 97 98 #define TCPOPT_TSTAMP_HDR \ 99 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 100 101 /* Option definitions */ 102 103 /* Warning: redundant with NOP, use it only in writing */ 104 #define TCPOPT_SACK_PERMIT_HDR \ 105 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED) 106 #define TCPOPT_SACK_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8) 107 /* Miscellaneous constants */ 108 #define MAX_SACK_BLKS 6 /* Max # SACK blocks stored at sender side */ 109 #define TCP_MAX_SACK 3 /* MAX # SACKs sent in any segment */ 110 111 #define TCP_MAXBURST 4 /* Max # packets after leaving Fast Rxmit */ 112 113 /* 114 * Default maximum segment size for TCP. 115 * With an IP MSS of 576, this is 536, 116 * but 512 is probably more convenient. 117 * This should be defined as min(512, IP_MSS - sizeof (struct tcpiphdr)). 118 */ 119 #define TCP_MSS 512 120 121 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 122 123 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 124 125 /* 126 * User-settable options (used with setsockopt). 127 */ 128 #define TCP_NODELAY 0x01 /* don't delay send to coalesce pkts */ 129 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 130 #define TCP_MD5SIG 0x04 /* enable TCP MD5 signature option */ 131 #define TCP_SACK_ENABLE 0x08 /* enable SACKs (if disabled by def.) */ 132 133 #endif /* _NETINET_TCP_H_ */ 134