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 51 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 52 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 53 54 /* 55 * TCP header. 56 * Per RFC 793, September, 1981. 57 */ 58 struct tcphdr { 59 u_short th_sport; /* source port */ 60 u_short th_dport; /* destination port */ 61 tcp_seq th_seq; /* sequence number */ 62 tcp_seq th_ack; /* acknowledgement number */ 63 #if _BYTE_ORDER == _LITTLE_ENDIAN 64 u_int th_x2:4, /* (unused) */ 65 th_off:4; /* data offset */ 66 #elif _BYTE_ORDER == _BIG_ENDIAN 67 u_int th_off:4, /* data offset */ 68 th_x2:4; /* (unused) */ 69 #else 70 #error "Byte order not implemented" 71 #endif 72 u_char th_flags; 73 #define TH_FIN 0x01 74 #define TH_SYN 0x02 75 #define TH_RST 0x04 76 #define TH_PUSH 0x08 77 #define TH_ACK 0x10 78 #define TH_URG 0x20 79 #define TH_ECE 0x40 80 #define TH_CWR 0x80 81 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) 82 83 u_short th_win; /* window */ 84 u_short th_sum; /* checksum */ 85 u_short th_urp; /* urgent pointer */ 86 }; 87 88 #define TCPOPT_EOL 0 89 #define TCPOPT_NOP 1 90 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) 91 #define TCPOPT_MAXSEG 2 92 #define TCPOLEN_MAXSEG 4 93 #define TCPOPT_WINDOW 3 94 #define TCPOLEN_WINDOW 3 95 #define TCPOPT_SACK_PERMITTED 4 96 #define TCPOLEN_SACK_PERMITTED 2 97 #define TCPOPT_SACK_PERMITTED_ALIGNED \ 98 (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) 99 #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 100 #define TCPOPT_SACK 5 101 #define TCPOLEN_SACK 2 102 #define TCPOLEN_SACK_BLOCK 8 103 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) 104 #define TCPOLEN_SACK_ALIGNED 4 105 #define TCPOPT_TIMESTAMP 8 106 #define TCPOLEN_TIMESTAMP 10 107 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 108 #define TCPOPT_TSTAMP_HDR \ 109 (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) 110 #define TCPOPT_CC 11 /* CC options: RFC-1644 */ 111 #define TCPOPT_CCNEW 12 112 #define TCPOPT_CCECHO 13 113 114 /* 115 * Default maximum segment size for TCP. 116 * With an IP MSS of 576, this is 536, 117 * but 512 is probably more convenient. 118 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 119 */ 120 #define TCP_MSS 512 121 122 /* 123 * TCP_MINMSS is defined to be 256 which is fine for the smallest 124 * link MTU (296 bytes, SLIP interface) in the Internet. 125 * However it is very unlikely to come across such low MTU interfaces 126 * these days (anno dato 2003). 127 * Probably it can be set to 512 without ill effects. But we play safe. 128 * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. 129 * Setting this to "0" disables the minmss check. 130 */ 131 #define TCP_MINMSS 256 132 133 /* 134 * Default maximum segment size for TCP6. 135 * With an IP6 MSS of 1280, this is 1220, 136 * but 1024 is probably more convenient. (xxx kazu in doubt) 137 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) 138 * 139 * NOTE: TCP_MIN_WINSHIFT is used when negotiating window scaling. Larger 140 * values are possible but apparently some firewires blows up if 141 * values larger then 5 are used, so use 5. 142 */ 143 #define TCP6_MSS 1024 144 145 #define TCP_MAXWIN 65535 /* max value for (unscaled) window */ 146 147 #define TCP_MIN_WINSHIFT 5 /* requested minimum (x32) */ 148 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 149 150 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 151 152 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 153 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 154 /* max space left for options */ 155 156 /* 157 * User-settable options (used with setsockopt). 158 */ 159 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 160 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 161 #define TCP_NOPUSH 0x04 /* don't push last block of write */ 162 #define TCP_NOOPT 0x08 /* don't use TCP options */ 163 164 #endif 165