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 */ 36 37 #ifndef _NETINET_TCP_H_ 38 #define _NETINET_TCP_H_ 39 40 #ifndef _SYS_TYPES_H_ 41 #include <sys/types.h> 42 #endif 43 #include <machine/endian.h> 44 45 typedef u_int32_t tcp_seq; 46 typedef int32_t tcp_seq_diff_t; 47 48 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 49 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 50 51 /* 52 * TCP header. 53 * Per RFC 793, September, 1981. 54 */ 55 struct tcphdr { 56 u_short th_sport; /* source port */ 57 u_short th_dport; /* destination port */ 58 tcp_seq th_seq; /* sequence number */ 59 tcp_seq th_ack; /* acknowledgement number */ 60 #if _BYTE_ORDER == _LITTLE_ENDIAN 61 u_int th_x2:4, /* (unused) */ 62 th_off:4; /* data offset */ 63 #elif _BYTE_ORDER == _BIG_ENDIAN 64 u_int th_off:4, /* data offset */ 65 th_x2:4; /* (unused) */ 66 #else 67 #error "Byte order not implemented" 68 #endif 69 u_char th_flags; 70 #define TH_FIN 0x01 71 #define TH_SYN 0x02 72 #define TH_RST 0x04 73 #define TH_PUSH 0x08 74 #define TH_ACK 0x10 75 #define TH_URG 0x20 76 #define TH_ECE 0x40 77 #define TH_CWR 0x80 78 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) 79 80 u_short th_win; /* window */ 81 u_short th_sum; /* checksum */ 82 u_short th_urp; /* urgent pointer */ 83 }; 84 85 #define TCPOPT_EOL 0 86 #define TCPOPT_NOP 1 87 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) 88 #define TCPOPT_MAXSEG 2 89 #define TCPOLEN_MAXSEG 4 90 #define TCPOPT_WINDOW 3 91 #define TCPOLEN_WINDOW 3 92 #define TCPOPT_SACK_PERMITTED 4 93 #define TCPOLEN_SACK_PERMITTED 2 94 #define TCPOPT_SACK_PERMITTED_ALIGNED \ 95 (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) 96 #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 97 #define TCPOPT_SACK 5 98 #define TCPOLEN_SACK 2 99 #define TCPOLEN_SACK_BLOCK 8 100 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) 101 #define TCPOLEN_SACK_ALIGNED 4 102 #define TCPOPT_TIMESTAMP 8 103 #define TCPOLEN_TIMESTAMP 10 104 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 105 #define TCPOPT_TSTAMP_HDR \ 106 (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) 107 #define TCPOPT_CC 11 /* CC options: RFC-1644 */ 108 #define TCPOPT_CCNEW 12 109 #define TCPOPT_CCECHO 13 110 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 111 #define TCPOLEN_SIGNATURE 18 112 113 /* 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 /* 122 * TCP_MINMSS is defined to be 256 which is fine for the smallest 123 * link MTU (296 bytes, SLIP interface) in the Internet. 124 * However it is very unlikely to come across such low MTU interfaces 125 * these days (anno dato 2003). 126 * Probably it can be set to 512 without ill effects. But we play safe. 127 * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. 128 * Setting this to "0" disables the minmss check. 129 */ 130 #define TCP_MINMSS 256 131 132 /* 133 * Default maximum segment size for TCP6. 134 * With an IP6 MSS of 1280, this is 1220, 135 * but 1024 is probably more convenient. (xxx kazu in doubt) 136 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) 137 * 138 * NOTE: TCP_MIN_WINSHIFT is used when negotiating window scaling. Larger 139 * values are possible but apparently some firewires blows up if 140 * values larger then 5 are used, so use 5. 141 */ 142 #define TCP6_MSS 1024 143 144 #define TCP_MAXWIN 65535 /* max value for (unscaled) window */ 145 146 #define TCP_MIN_WINSHIFT 5 /* requested minimum (x32) */ 147 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 148 149 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 150 151 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 152 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 153 /* max space left for options */ 154 155 /* 156 * User-settable options (used with setsockopt). 157 */ 158 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 159 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 160 #define TCP_NOPUSH 0x04 /* don't push last block of write */ 161 #define TCP_NOOPT 0x08 /* don't use TCP options */ 162 #define TCP_SIGNATURE_ENABLE 0x10 /* use MD5 digests (RFC2385) */ 163 #define TCP_KEEPINIT 0x20 /* set max time to establish connection */ 164 /* 0x40 unused */ 165 #define TCP_FASTKEEP 0x80 166 #define TCP_KEEPIDLE 0x100 /* set time before keepalive probes begin */ 167 #define TCP_KEEPINTVL 0x200 /* set time between keepalive probes */ 168 #define TCP_KEEPCNT 0x400 /* set max number of keepalive probes */ 169 170 #endif 171