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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 30 * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $ 31 */ 32 33 #ifndef _NETINET_TCP_H_ 34 #define _NETINET_TCP_H_ 35 36 #ifndef _SYS_TYPES_H_ 37 #include <sys/types.h> 38 #endif 39 #include <machine/endian.h> 40 41 typedef u_int32_t tcp_seq; 42 typedef int32_t tcp_seq_diff_t; 43 44 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 45 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 46 47 /* 48 * TCP header. 49 * Per RFC 793, September, 1981. 50 */ 51 struct tcphdr { 52 u_short th_sport; /* source port */ 53 u_short th_dport; /* destination port */ 54 tcp_seq th_seq; /* sequence number */ 55 tcp_seq th_ack; /* acknowledgement number */ 56 #if _BYTE_ORDER == _LITTLE_ENDIAN 57 u_int th_x2:4, /* (unused) */ 58 th_off:4; /* data offset */ 59 #elif _BYTE_ORDER == _BIG_ENDIAN 60 u_int th_off:4, /* data offset */ 61 th_x2:4; /* (unused) */ 62 #else 63 #error "Byte order not implemented" 64 #endif 65 u_char th_flags; 66 #define TH_FIN 0x01 67 #define TH_SYN 0x02 68 #define TH_RST 0x04 69 #define TH_PUSH 0x08 70 #define TH_ACK 0x10 71 #define TH_URG 0x20 72 #define TH_ECE 0x40 73 #define TH_CWR 0x80 74 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) 75 76 u_short th_win; /* window */ 77 u_short th_sum; /* checksum */ 78 u_short th_urp; /* urgent pointer */ 79 }; 80 81 #define TCPOPT_EOL 0 82 #define TCPOPT_NOP 1 83 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) 84 #define TCPOPT_MAXSEG 2 85 #define TCPOLEN_MAXSEG 4 86 #define TCPOPT_WINDOW 3 87 #define TCPOLEN_WINDOW 3 88 #define TCPOPT_SACK_PERMITTED 4 89 #define TCPOLEN_SACK_PERMITTED 2 90 #define TCPOPT_SACK_PERMITTED_ALIGNED \ 91 (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) 92 #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 93 #define TCPOPT_SACK 5 94 #define TCPOLEN_SACK 2 95 #define TCPOLEN_SACK_BLOCK 8 96 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) 97 #define TCPOLEN_SACK_ALIGNED 4 98 #define TCPOPT_TIMESTAMP 8 99 #define TCPOLEN_TIMESTAMP 10 100 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 101 #define TCPOPT_TSTAMP_HDR \ 102 (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) 103 #define TCPOPT_CC 11 /* CC options: RFC-1644 */ 104 #define TCPOPT_CCNEW 12 105 #define TCPOPT_CCECHO 13 106 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 107 #define TCPOLEN_SIGNATURE 18 108 109 /* 110 * Default maximum segment size for TCP. 111 * With an IP MSS of 576, this is 536, 112 * but 512 is probably more convenient. 113 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 114 */ 115 #define TCP_MSS 512 116 117 /* 118 * TCP_MINMSS is defined to be 256 which is fine for the smallest 119 * link MTU (296 bytes, SLIP interface) in the Internet. 120 * However it is very unlikely to come across such low MTU interfaces 121 * these days (anno dato 2003). 122 * Probably it can be set to 512 without ill effects. But we play safe. 123 * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. 124 * Setting this to "0" disables the minmss check. 125 */ 126 #define TCP_MINMSS 256 127 128 /* 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 * NOTE: TCP_MIN_WINSHIFT is used when negotiating window scaling. Larger 135 * values are possible but apparently some firewires blows up if 136 * values larger then 5 are used, so use 5. 137 */ 138 #define TCP6_MSS 1024 139 140 #define TCP_MAXWIN 65535 /* max value for (unscaled) window */ 141 142 #define TCP_MIN_WINSHIFT 5 /* requested minimum (x32) */ 143 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 144 145 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 146 147 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 148 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 149 /* max space left for options */ 150 151 /* 152 * User-settable options (used with setsockopt). 153 */ 154 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 155 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 156 #define TCP_NOPUSH 0x04 /* don't push last block of write */ 157 #define TCP_NOOPT 0x08 /* don't use TCP options */ 158 #define TCP_SIGNATURE_ENABLE 0x10 /* use MD5 digests (RFC2385) */ 159 #define TCP_KEEPINIT 0x20 /* set max time to establish connection */ 160 /* 0x40 unused */ 161 #define TCP_FASTKEEP 0x80 162 #define TCP_KEEPIDLE 0x100 /* set time before keepalive probes begin */ 163 #define TCP_KEEPINTVL 0x200 /* set time between keepalive probes */ 164 #define TCP_KEEPCNT 0x400 /* set max number of keepalive probes */ 165 166 #endif 167