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 #include <sys/cdefs.h> 37 38 #if __BSD_VISIBLE 39 40 #include <sys/types.h> 41 42 typedef uint32_t tcp_seq; 43 typedef int32_t tcp_seq_diff_t; 44 45 #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 46 #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 47 48 /* 49 * TCP header. 50 * Per RFC 793, September, 1981. 51 */ 52 struct tcphdr { 53 u_short th_sport; /* source port */ 54 u_short th_dport; /* destination port */ 55 tcp_seq th_seq; /* sequence number */ 56 tcp_seq th_ack; /* acknowledgement number */ 57 #if _BYTE_ORDER == _LITTLE_ENDIAN 58 u_int th_x2:4, /* (unused) */ 59 th_off:4; /* data offset */ 60 #elif _BYTE_ORDER == _BIG_ENDIAN 61 u_int th_off:4, /* data offset */ 62 th_x2:4; /* (unused) */ 63 #else 64 #error "Byte order not implemented" 65 #endif 66 u_char th_flags; 67 #define TH_FIN 0x01 68 #define TH_SYN 0x02 69 #define TH_RST 0x04 70 #define TH_PUSH 0x08 71 #define TH_ACK 0x10 72 #define TH_URG 0x20 73 #define TH_ECE 0x40 74 #define TH_CWR 0x80 75 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) 76 77 u_short th_win; /* window */ 78 u_short th_sum; /* checksum */ 79 u_short th_urp; /* urgent pointer */ 80 }; 81 82 #define TCPOPT_EOL 0 83 #define TCPOPT_NOP 1 84 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) 85 #define TCPOPT_MAXSEG 2 86 #define TCPOLEN_MAXSEG 4 87 #define TCPOPT_WINDOW 3 88 #define TCPOLEN_WINDOW 3 89 #define TCPOPT_SACK_PERMITTED 4 90 #define TCPOLEN_SACK_PERMITTED 2 91 #define TCPOPT_SACK_PERMITTED_ALIGNED \ 92 (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) 93 #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 94 #define TCPOPT_SACK 5 95 #define TCPOLEN_SACK 2 96 #define TCPOLEN_SACK_BLOCK 8 97 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) 98 #define TCPOLEN_SACK_ALIGNED 4 99 #define TCPOPT_TIMESTAMP 8 100 #define TCPOLEN_TIMESTAMP 10 101 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 102 #define TCPOPT_TSTAMP_HDR \ 103 (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) 104 #define TCPOPT_CC 11 /* CC options: RFC-1644 */ 105 #define TCPOPT_CCNEW 12 106 #define TCPOPT_CCECHO 13 107 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 108 #define TCPOLEN_SIGNATURE 18 109 110 /* 111 * Default maximum segment size for TCP. 112 * With an IP MSS of 576, this is 536, 113 * but 512 is probably more convenient. 114 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 115 */ 116 #define TCP_MSS 512 117 118 /* 119 * TCP_MINMSS is defined to be 256 which is fine for the smallest 120 * link MTU (296 bytes, SLIP interface) in the Internet. 121 * However it is very unlikely to come across such low MTU interfaces 122 * these days (anno dato 2003). 123 * Probably it can be set to 512 without ill effects. But we play safe. 124 * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. 125 * Setting this to "0" disables the minmss check. 126 */ 127 #define TCP_MINMSS 256 128 129 /* 130 * Default maximum segment size for TCP6. 131 * With an IP6 MSS of 1280, this is 1220, 132 * but 1024 is probably more convenient. (xxx kazu in doubt) 133 * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) 134 * 135 * NOTE: TCP_MIN_WINSHIFT is used when negotiating window scaling. Larger 136 * values are possible but apparently some firewires blows up if 137 * values larger then 5 are used, so use 5. 138 */ 139 #define TCP6_MSS 1024 140 141 #define TCP_MAXWIN 65535 /* max value for (unscaled) window */ 142 143 #define TCP_MIN_WINSHIFT 5 /* requested minimum (x32) */ 144 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 145 146 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 147 148 #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 149 #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 150 /* max space left for options */ 151 #endif /* __BSD_VISIBLE */ 152 153 /* 154 * User-settable options (used with setsockopt). 155 */ 156 #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 157 #if __BSD_VISIBLE 158 #define TCP_MAXSEG 0x02 /* set maximum segment size */ 159 #define TCP_NOPUSH 0x04 /* don't push last block of write */ 160 #define TCP_NOOPT 0x08 /* don't use TCP options */ 161 #define TCP_SIGNATURE_ENABLE 0x10 /* use MD5 digests (RFC2385) */ 162 #define TCP_KEEPINIT 0x20 /* set max time to establish connection */ 163 /* 0x40 unused */ 164 #define TCP_FASTKEEP 0x80 165 #define TCP_KEEPIDLE 0x100 /* set time before keepalive probes begin */ 166 #define TCP_KEEPINTVL 0x200 /* set time between keepalive probes */ 167 #define TCP_KEEPCNT 0x400 /* set max number of keepalive probes */ 168 #endif /* __BSD_VISIBLE */ 169 170 #endif 171