1 /* 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. 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 * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $ 35 * $DragonFly: src/sys/netinet/tcp.h,v 1.7 2006/05/20 02:42:12 dillon Exp $ 36 */ 37 38 #ifndef _NETINET_TCP_H_ 39 #define _NETINET_TCP_H_ 40 41 #ifndef _SYS_TYPES_H_ 42 #include <sys/types.h> 43 #endif 44 #ifndef _MACHINE_ENDIAN_H_ 45 #include <machine/endian.h> 46 #endif 47 48 typedef u_int32_t tcp_seq; 49 typedef int32_t tcp_seq_diff_t; 50 typedef u_int32_t tcp_cc; /* connection count per rfc1644 */ 51 52 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 53 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 54 55 /* 56 * TCP header. 57 * Per RFC 793, September, 1981. 58 */ 59 struct tcphdr { 60 u_short th_sport; /* source port */ 61 u_short th_dport; /* destination port */ 62 tcp_seq th_seq; /* sequence number */ 63 tcp_seq th_ack; /* acknowledgement number */ 64 #if _BYTE_ORDER == _LITTLE_ENDIAN 65 u_int th_x2:4, /* (unused) */ 66 th_off:4; /* data offset */ 67 #elif _BYTE_ORDER == _BIG_ENDIAN 68 u_int th_off:4, /* data offset */ 69 th_x2:4; /* (unused) */ 70 #else 71 #error "Byte order not implemented" 72 #endif 73 u_char th_flags; 74 #define TH_FIN 0x01 75 #define TH_SYN 0x02 76 #define TH_RST 0x04 77 #define TH_PUSH 0x08 78 #define TH_ACK 0x10 79 #define TH_URG 0x20 80 #define TH_ECE 0x40 81 #define TH_CWR 0x80 82 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) 83 84 u_short th_win; /* window */ 85 u_short th_sum; /* checksum */ 86 u_short th_urp; /* urgent pointer */ 87 }; 88 89 #define TCPOPT_EOL 0 90 #define TCPOPT_NOP 1 91 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) 92 #define TCPOPT_MAXSEG 2 93 #define TCPOLEN_MAXSEG 4 94 #define TCPOPT_WINDOW 3 95 #define TCPOLEN_WINDOW 3 96 #define TCPOPT_SACK_PERMITTED 4 97 #define TCPOLEN_SACK_PERMITTED 2 98 #define TCPOPT_SACK_PERMITTED_ALIGNED \ 99 (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) 100 #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 101 #define TCPOPT_SACK 5 102 #define TCPOLEN_SACK 2 103 #define TCPOLEN_SACK_BLOCK 8 104 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) 105 #define TCPOLEN_SACK_ALIGNED 4 106 #define TCPOPT_TIMESTAMP 8 107 #define TCPOLEN_TIMESTAMP 10 108 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 109 #define TCPOPT_TSTAMP_HDR \ 110 (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) 111 #define TCPOPT_CC 11 /* CC options: RFC-1644 */ 112 #define TCPOPT_CCNEW 12 113 #define TCPOPT_CCECHO 13 114 #define TCPOLEN_CC 6 115 #define TCPOLEN_CC_APPA (TCPOLEN_CC+2) 116 #define TCPOPT_CC_HDR(ccopt) \ 117 (TCPOPT_2NOPs | (ccopt) << 8 | TCPOLEN_CC) 118 119 /* 120 * Default maximum segment size for TCP. 121 * With an IP MSS of 576, this is 536, 122 * but 512 is probably more convenient. 123 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 124 * The modern consensus is that 1500 is a safe MTU to use for the Internet. 125 */ 126 #define TCP_MSS 1460 127 128 /* 129 * Default maximum segment size for TCP6. 130 * With an IP6 MSS of 1280, this is 1220, 131 * but 1024 is probably more convenient. (xxx kazu in doubt) 132 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) 133 */ 134 #define TCP6_MSS 1024 135 136 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 137 #define TTCP_CLIENT_SND_WND 4096 /* dflt send window for T/TCP client */ 138 139 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 140 141 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 142 143 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 144 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 145 /* max space left for options */ 146 147 /* 148 * User-settable options (used with setsockopt). 149 */ 150 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 151 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 152 #define TCP_NOPUSH 0x04 /* don't push last block of write */ 153 #define TCP_NOOPT 0x08 /* don't use TCP options */ 154 155 #endif 156