1 /* $NetBSD: tcp.h,v 1.31 2015/02/14 12:57:53 he Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 32 */ 33 34 #ifndef _NETINET_TCP_H_ 35 #define _NETINET_TCP_H_ 36 37 #include <sys/featuretest.h> 38 39 #if defined(_NETBSD_SOURCE) 40 #include <sys/types.h> 41 42 typedef uint32_t tcp_seq; 43 /* 44 * TCP header. 45 * Per RFC 793, September, 1981. 46 * Updated by RFC 3168, September, 2001. 47 */ 48 struct tcphdr { 49 uint16_t th_sport; /* source port */ 50 uint16_t th_dport; /* destination port */ 51 tcp_seq th_seq; /* sequence number */ 52 tcp_seq th_ack; /* acknowledgement number */ 53 #if BYTE_ORDER == LITTLE_ENDIAN 54 /*LINTED non-portable bitfields*/ 55 uint8_t th_x2:4, /* (unused) */ 56 th_off:4; /* data offset */ 57 #endif 58 #if BYTE_ORDER == BIG_ENDIAN 59 /*LINTED non-portable bitfields*/ 60 uint8_t th_off:4, /* data offset */ 61 th_x2:4; /* (unused) */ 62 #endif 63 uint8_t th_flags; 64 #define TH_FIN 0x01 65 #define TH_SYN 0x02 66 #define TH_RST 0x04 67 #define TH_PUSH 0x08 68 #define TH_ACK 0x10 69 #define TH_URG 0x20 70 #define TH_ECE 0x40 71 #define TH_CWR 0x80 72 uint16_t th_win; /* window */ 73 uint16_t th_sum; /* checksum */ 74 uint16_t th_urp; /* urgent pointer */ 75 } __packed; 76 77 #define TCPOPT_EOL 0 78 #define TCPOPT_NOP 1 79 #define TCPOPT_MAXSEG 2 80 #define TCPOLEN_MAXSEG 4 81 #define TCPOPT_WINDOW 3 82 #define TCPOLEN_WINDOW 3 83 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 84 #define TCPOLEN_SACK_PERMITTED 2 85 #define TCPOPT_SACK 5 /* Experimental */ 86 #define TCPOPT_TIMESTAMP 8 87 #define TCPOLEN_TIMESTAMP 10 88 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 89 90 #define TCPOPT_TSTAMP_HDR \ 91 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 92 93 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ 94 #define TCPOLEN_SIGNATURE 18 95 #define TCPOLEN_SIGLEN (TCPOLEN_SIGNATURE+2) /* padding */ 96 97 #define MAX_TCPOPTLEN 40 /* max # bytes that go in options */ 98 99 /* 100 * Default maximum segment size for TCP. 101 * This is defined by RFC 1112 Sec 4.2.2.6. 102 */ 103 #define TCP_MSS 536 104 105 #define TCP_MINMSS 216 106 107 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 108 109 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 110 111 #define TCP_MAXBURST 4 /* maximum segments in a burst */ 112 113 #endif /* _NETBSD_SOURCE */ 114 115 /* 116 * User-settable options (used with setsockopt). 117 */ 118 #define TCP_NODELAY 1 /* don't delay send to coalesce packets */ 119 #define TCP_MAXSEG 2 /* set maximum segment size */ 120 #define TCP_KEEPIDLE 3 121 #ifdef notyet 122 #define TCP_NOPUSH 4 /* reserved for FreeBSD compat */ 123 #endif 124 #define TCP_KEEPINTVL 5 125 #define TCP_KEEPCNT 6 126 #define TCP_KEEPINIT 7 127 #ifdef notyet 128 #define TCP_NOOPT 8 /* reserved for FreeBSD compat */ 129 #endif 130 #define TCP_INFO 9 /* retrieve tcp_info structure */ 131 #define TCP_MD5SIG 0x10 /* use MD5 digests (RFC2385) */ 132 #define TCP_CONGCTL 0x20 /* selected congestion control */ 133 134 #define TCPI_OPT_TIMESTAMPS 0x01 135 #define TCPI_OPT_SACK 0x02 136 #define TCPI_OPT_WSCALE 0x04 137 #define TCPI_OPT_ECN 0x08 138 #define TCPI_OPT_TOE 0x10 139 140 /* 141 * The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits 142 * the caller to query certain information about the state of a TCP 143 * connection. We provide an overlapping set of fields with the Linux 144 * implementation, but since this is a fixed size structure, room has been 145 * left for growth. In order to maximize potential future compatibility with 146 * the Linux API, the same variable names and order have been adopted, and 147 * padding left to make room for omitted fields in case they are added later. 148 * 149 * XXX: This is currently an unstable ABI/API, in that it is expected to 150 * change. 151 */ 152 struct tcp_info { 153 uint8_t tcpi_state; /* TCP FSM state. */ 154 uint8_t __tcpi_ca_state; 155 uint8_t __tcpi_retransmits; 156 uint8_t __tcpi_probes; 157 uint8_t __tcpi_backoff; 158 uint8_t tcpi_options; /* Options enabled on conn. */ 159 uint8_t tcpi_snd_wscale:4, /* RFC1323 send shift value. */ 160 tcpi_rcv_wscale:4; /* RFC1323 recv shift value. */ 161 162 uint32_t tcpi_rto; /* Retransmission timeout (usec). */ 163 uint32_t __tcpi_ato; 164 uint32_t tcpi_snd_mss; /* Max segment size for send. */ 165 uint32_t tcpi_rcv_mss; /* Max segment size for receive. */ 166 167 uint32_t __tcpi_unacked; 168 uint32_t __tcpi_sacked; 169 uint32_t __tcpi_lost; 170 uint32_t __tcpi_retrans; 171 uint32_t __tcpi_fackets; 172 173 /* Times; measurements in usecs. */ 174 uint32_t __tcpi_last_data_sent; 175 uint32_t __tcpi_last_ack_sent; /* Also unimpl. on Linux? */ 176 uint32_t tcpi_last_data_recv; /* Time since last recv data. */ 177 uint32_t __tcpi_last_ack_recv; 178 179 /* Metrics; variable units. */ 180 uint32_t __tcpi_pmtu; 181 uint32_t __tcpi_rcv_ssthresh; 182 uint32_t tcpi_rtt; /* Smoothed RTT in usecs. */ 183 uint32_t tcpi_rttvar; /* RTT variance in usecs. */ 184 uint32_t tcpi_snd_ssthresh; /* Slow start threshold. */ 185 uint32_t tcpi_snd_cwnd; /* Send congestion window. */ 186 uint32_t __tcpi_advmss; 187 uint32_t __tcpi_reordering; 188 189 uint32_t __tcpi_rcv_rtt; 190 uint32_t tcpi_rcv_space; /* Advertised recv window. */ 191 192 /* FreeBSD/NetBSD extensions to tcp_info. */ 193 uint32_t tcpi_snd_wnd; /* Advertised send window. */ 194 uint32_t tcpi_snd_bwnd; /* No longer used. */ 195 uint32_t tcpi_snd_nxt; /* Next egress seqno */ 196 uint32_t tcpi_rcv_nxt; /* Next ingress seqno */ 197 uint32_t tcpi_toe_tid; /* HWTID for TOE endpoints */ 198 uint32_t tcpi_snd_rexmitpack; /* Retransmitted packets */ 199 uint32_t tcpi_rcv_ooopack; /* Out-of-order packets */ 200 uint32_t tcpi_snd_zerowin; /* Zero-sized windows sent */ 201 202 /* Padding to grow without breaking ABI. */ 203 uint32_t __tcpi_pad[26]; /* Padding. */ 204 }; 205 206 #endif /* !_NETINET_TCP_H_ */ 207