tcp.h revision 167606
1281SN/A/*- 2281SN/A * Copyright (c) 1982, 1986, 1993 3281SN/A * The Regents of the University of California. All rights reserved. 4281SN/A * 5281SN/A * Redistribution and use in source and binary forms, with or without 61113Sjoehw * modification, are permitted provided that the following conditions 71113Sjoehw * are met: 81113Sjoehw * 1. Redistributions of source code must retain the above copyright 91113Sjoehw * notice, this list of conditions and the following disclaimer. 101113Sjoehw * 2. Redistributions in binary form must reproduce the above copyright 111113Sjoehw * notice, this list of conditions and the following disclaimer in the 12281SN/A * documentation and/or other materials provided with the distribution. 13281SN/A * 4. Neither the name of the University nor the names of its contributors 14281SN/A * may be used to endorse or promote products derived from this software 15281SN/A * without specific prior written permission. 16281SN/A * 17281SN/A * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18281SN/A * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19281SN/A * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20281SN/A * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21281SN/A * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22281SN/A * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23281SN/A * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24281SN/A * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25281SN/A * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26510SN/A * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27464SN/A * SUCH DAMAGE. 28281SN/A * 29281SN/A * @(#)tcp.h 8.1 (Berkeley) 6/10/93 30464SN/A * $FreeBSD: head/sys/netinet/tcp.h 167606 2007-03-15 15:59:28Z andre $ 31464SN/A */ 32281SN/A 33281SN/A#ifndef _NETINET_TCP_H_ 34281SN/A#define _NETINET_TCP_H_ 35281SN/A 36281SN/A#include <sys/cdefs.h> 37281SN/A 38281SN/A#if __BSD_VISIBLE 39281SN/A 40281SN/Atypedef u_int32_t tcp_seq; 41281SN/A 42281SN/A#define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ 43281SN/A#define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ 44281SN/A 45281SN/A/* 46281SN/A * TCP header. 47281SN/A * Per RFC 793, September, 1981. 48281SN/A */ 49281SN/Astruct tcphdr { 50281SN/A u_short th_sport; /* source port */ 51281SN/A u_short th_dport; /* destination port */ 52281SN/A tcp_seq th_seq; /* sequence number */ 53281SN/A tcp_seq th_ack; /* acknowledgement number */ 54281SN/A#if BYTE_ORDER == LITTLE_ENDIAN 55281SN/A u_int th_x2:4, /* (unused) */ 56281SN/A th_off:4; /* data offset */ 57281SN/A#endif 58281SN/A#if BYTE_ORDER == BIG_ENDIAN 59281SN/A u_int th_off:4, /* data offset */ 60281SN/A th_x2:4; /* (unused) */ 61281SN/A#endif 62281SN/A u_char th_flags; 63281SN/A#define TH_FIN 0x01 64281SN/A#define TH_SYN 0x02 65281SN/A#define TH_RST 0x04 66281SN/A#define TH_PUSH 0x08 67281SN/A#define TH_ACK 0x10 68281SN/A#define TH_URG 0x20 69281SN/A#define TH_ECE 0x40 70281SN/A#define TH_CWR 0x80 71281SN/A#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG|TH_ECE|TH_CWR) 72281SN/A 73281SN/A u_short th_win; /* window */ 74281SN/A u_short th_sum; /* checksum */ 75281SN/A u_short th_urp; /* urgent pointer */ 76281SN/A}; 77281SN/A 78281SN/A#define TCPOPT_EOL 0 79281SN/A#define TCPOLEN_EOL 1 80515SN/A#define TCPOPT_NOP 1 81281SN/A#define TCPOLEN_NOP 1 82281SN/A#define TCPOPT_MAXSEG 2 83281SN/A#define TCPOLEN_MAXSEG 4 84281SN/A#define TCPOPT_WINDOW 3 85281SN/A#define TCPOLEN_WINDOW 3 86281SN/A#define TCPOPT_SACK_PERMITTED 4 87281SN/A#define TCPOLEN_SACK_PERMITTED 2 88281SN/A#define TCPOPT_SACK 5 89281SN/A#define TCPOLEN_SACKHDR 2 90281SN/A#define TCPOLEN_SACK 8 /* 2*sizeof(tcp_seq) */ 91281SN/A#define TCPOPT_TIMESTAMP 8 92281SN/A#define TCPOLEN_TIMESTAMP 10 93281SN/A#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 94281SN/A#define TCPOPT_TSTAMP_HDR \ 95281SN/A (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 96281SN/A 97281SN/A#define MAX_TCPOPTLEN 40 /* Absolute maximum TCP options len */ 98281SN/A 99281SN/A#define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 100281SN/A#define TCPOLEN_SIGNATURE 18 101281SN/A 102281SN/A/* Option definitions */ 103281SN/A#define TCPOPT_SACK_PERMIT_HDR \ 104281SN/A(TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED) 105281SN/A#define TCPOPT_SACK_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8) 106281SN/A/* Miscellaneous constants */ 107281SN/A#define MAX_SACK_BLKS 6 /* Max # SACK blocks stored at receiver side */ 108281SN/A#define TCP_MAX_SACK 4 /* MAX # SACKs sent in any segment */ 109281SN/A 110281SN/A 111293SN/A/* 112281SN/A * Default maximum segment size for TCP. 113281SN/A * With an IP MTU of 576, this is 536, 114281SN/A * but 512 is probably more convenient. 115281SN/A * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 116281SN/A */ 117281SN/A#define TCP_MSS 512 118281SN/A/* 119281SN/A * TCP_MINMSS is defined to be 216 which is fine for the smallest 120281SN/A * link MTU (256 bytes, AX.25 packet radio) in the Internet. 121281SN/A * However it is very unlikely to come across such low MTU interfaces 122281SN/A * these days (anno dato 2003). 123281SN/A * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. 124281SN/A * Setting this to "0" disables the minmss check. 125281SN/A */ 126281SN/A#define TCP_MINMSS 216 127281SN/A/* 128464SN/A * TCP_MINMSSOVERLOAD is defined to be 1000 which should cover any type 129464SN/A * of interactive TCP session. 130464SN/A * See tcp_subr.c tcp_minmssoverload SYSCTL declaration and tcp_input.c 131464SN/A * for more comments. 132464SN/A * Setting this to "0" disables the minmssoverload check. 133464SN/A */ 134515SN/A#define TCP_MINMSSOVERLOAD 0 /* XXX: Disabled until refined */ 135515SN/A 136515SN/A/* 137515SN/A * Default maximum segment size for TCP6. 138515SN/A * With an IP6 MSS of 1280, this is 1220, 139515SN/A * but 1024 is probably more convenient. (xxx kazu in doubt) 140515SN/A * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) 141515SN/A */ 142515SN/A#define TCP6_MSS 1024 143515SN/A 144515SN/A#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 145515SN/A#define TTCP_CLIENT_SND_WND 4096 /* dflt send window for T/TCP client */ 146515SN/A 147515SN/A#define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 148515SN/A 149515SN/A#define TCP_MAXBURST 4 /* maximum segments in a burst */ 150515SN/A 151515SN/A#define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ 152515SN/A#define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) 153515SN/A /* max space left for options */ 154515SN/A#endif /* __BSD_VISIBLE */ 155515SN/A 156515SN/A/* 157515SN/A * User-settable options (used with setsockopt). 158510SN/A */ 159510SN/A#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 160515SN/A#if __BSD_VISIBLE 161510SN/A#define TCP_MAXSEG 0x02 /* set maximum segment size */ 162515SN/A#define TCP_NOPUSH 0x04 /* don't push last block of write */ 163510SN/A#define TCP_NOOPT 0x08 /* don't use TCP options */ 164464SN/A#define TCP_MD5SIG 0x10 /* use MD5 digests (RFC2385) */ 165464SN/A#define TCP_INFO 0x20 /* retrieve tcp_info structure */ 166464SN/A 167464SN/A#define TCPI_OPT_TIMESTAMPS 0x01 168464SN/A#define TCPI_OPT_SACK 0x02 169464SN/A#define TCPI_OPT_WSCALE 0x04 170510SN/A#define TCPI_OPT_ECN 0x08 171464SN/A 172510SN/A/* 173515SN/A * The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits 174515SN/A * the caller to query certain information about the state of a TCP 175510SN/A * connection. We provide an overlapping set of fields with the Linux 176510SN/A * implementation, but since this is a fixed size structure, room has been 177464SN/A * left for growth. In order to maximize potential future compatibility with 178464SN/A * the Linux API, the same variable names and order have been adopted, and 179281SN/A * padding left to make room for omitted fields in case they are added later. 180 * 181 * XXX: This is currently an unstable ABI/API, in that it is expected to 182 * change. 183 */ 184struct tcp_info { 185 u_int8_t tcpi_state; /* TCP FSM state. */ 186 u_int8_t __tcpi_ca_state; 187 u_int8_t __tcpi_retransmits; 188 u_int8_t __tcpi_probes; 189 u_int8_t __tcpi_backoff; 190 u_int8_t tcpi_options; /* Options enabled on conn. */ 191 u_int8_t tcpi_snd_wscale:4, /* RFC1323 send shift value. */ 192 tcpi_rcv_wscale:4; /* RFC1323 recv shift value. */ 193 194 u_int32_t __tcpi_rto; 195 u_int32_t __tcpi_ato; 196 u_int32_t __tcpi_snd_mss; 197 u_int32_t __tcpi_rcv_mss; 198 199 u_int32_t __tcpi_unacked; 200 u_int32_t __tcpi_sacked; 201 u_int32_t __tcpi_lost; 202 u_int32_t __tcpi_retrans; 203 u_int32_t __tcpi_fackets; 204 205 /* Times; measurements in usecs. */ 206 u_int32_t __tcpi_last_data_sent; 207 u_int32_t __tcpi_last_ack_sent; /* Also unimpl. on Linux? */ 208 u_int32_t __tcpi_last_data_recv; 209 u_int32_t __tcpi_last_ack_recv; 210 211 /* Metrics; variable units. */ 212 u_int32_t __tcpi_pmtu; 213 u_int32_t __tcpi_rcv_ssthresh; 214 u_int32_t tcpi_rtt; /* Smoothed RTT in usecs. */ 215 u_int32_t tcpi_rttvar; /* RTT variance in usecs. */ 216 u_int32_t tcpi_snd_ssthresh; /* Slow start threshold. */ 217 u_int32_t tcpi_snd_cwnd; /* Send congestion window. */ 218 u_int32_t __tcpi_advmss; 219 u_int32_t __tcpi_reordering; 220 221 u_int32_t __tcpi_rcv_rtt; 222 u_int32_t tcpi_rcv_space; /* Advertised recv window. */ 223 224 /* FreeBSD extensions to tcp_info. */ 225 u_int32_t tcpi_snd_wnd; /* Advertised send window. */ 226 u_int32_t tcpi_snd_bwnd; /* Bandwidth send window. */ 227 228 /* Padding to grow without breaking ABI. */ 229 u_int32_t __tcpi_pad[32]; /* Padding. */ 230}; 231#endif 232 233#endif /* !_NETINET_TCP_H_ */ 234