/* $OpenBSD: tcp.h,v 1.24 2023/05/19 01:04:39 guenther Exp $ */ /* $NetBSD: tcp.h,v 1.8 1995/04/17 05:32:58 cgd Exp $ */ /* * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)tcp.h 8.1 (Berkeley) 6/10/93 */ #ifndef _NETINET_TCP_H_ #define _NETINET_TCP_H_ #include <sys/cdefs.h> #if __BSD_VISIBLE typedef u_int32_t tcp_seq; /* * TCP header. * Per RFC 793, September, 1981. */ struct tcphdr { u_int16_t th_sport; /* source port */ u_int16_t th_dport; /* destination port */ tcp_seq th_seq; /* sequence number */ tcp_seq th_ack; /* acknowledgement number */ #if _BYTE_ORDER == _LITTLE_ENDIAN u_int32_t th_x2:4, /* (unused) */ th_off:4; /* data offset */ #endif #if _BYTE_ORDER == _BIG_ENDIAN u_int32_t th_off:4, /* data offset */ th_x2:4; /* (unused) */ #endif u_int8_t th_flags; #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_PUSH 0x08 #define TH_ACK 0x10 #define TH_URG 0x20 #define TH_ECE 0x40 #define TH_CWR 0x80 u_int16_t th_win; /* window */ u_int16_t th_sum; /* checksum */ u_int16_t th_urp; /* urgent pointer */ }; #define th_reseqlen th_urp /* TCP data length for resequencing/reassembly */ #define TCPOPT_EOL 0 #define TCPOPT_NOP 1 #define TCPOPT_MAXSEG 2 #define TCPOLEN_MAXSEG 4 #define TCPOPT_WINDOW 3 #define TCPOLEN_WINDOW 3 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ #define TCPOLEN_SACK_PERMITTED 2 #define TCPOPT_SACK 5 /* Experimental */ #define TCPOLEN_SACK 8 /* 2*sizeof(tcp_seq) */ #define TCPOPT_TIMESTAMP 8 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ #define TCPOPT_SIGNATURE 19 #define TCPOLEN_SIGNATURE 18 #define TCPOLEN_SIGLEN (TCPOLEN_SIGNATURE+2) /* padding */ #define MAX_TCPOPTLEN 40 /* Absolute maximum TCP options len */ #define TCPOPT_TSTAMP_HDR \ (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) /* Option definitions */ #define TCPOPT_SACK_PERMIT_HDR \ (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED) #define TCPOPT_SACK_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8) /* Miscellaneous constants */ #define MAX_SACK_BLKS 6 /* Max # SACK blocks stored at sender side */ #define TCP_MAX_SACK 3 /* Max # SACKs sent in any segment */ #define TCP_SACKHOLE_LIMIT 128 /* Max # SACK holes per connection */ /* * Default maximum segment size for TCP. * With an IP MSS of 576, this is 536, * but 512 is probably more convenient. * This should be defined as min(512, IP_MSS - sizeof (struct tcpiphdr)). */ #define TCP_MSS 512 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ /* * The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits * the caller to query certain information about the state of a TCP * connection. Provide an overlapping set of fields with the Linux * implementation, but at the same time add a lot of OpenBSD specific * extra information. */ struct tcp_info { uint8_t tcpi_state; /* TCP FSM state. */ uint8_t __tcpi_ca_state; uint8_t __tcpi_retransmits; uint8_t __tcpi_probes; uint8_t __tcpi_backoff; uint8_t tcpi_options; /* Options enabled on conn. */ #define TCPI_OPT_TIMESTAMPS 0x01 #define TCPI_OPT_SACK 0x02 #define TCPI_OPT_WSCALE 0x04 #define TCPI_OPT_ECN 0x08 #define TCPI_OPT_TOE 0x10 uint8_t tcpi_snd_wscale; /* RFC1323 send shift value. */ uint8_t tcpi_rcv_wscale; /* RFC1323 recv shift value. */ uint32_t tcpi_rto; /* Retransmission timeout (usec). */ uint32_t __tcpi_ato; uint32_t tcpi_snd_mss; /* Max segment size for send. */ uint32_t tcpi_rcv_mss; /* Max segment size for recv. */ uint32_t __tcpi_unacked; uint32_t __tcpi_sacked; uint32_t __tcpi_lost; uint32_t __tcpi_retrans; uint32_t __tcpi_fackets; /* Times; measurements in usecs. */ uint32_t tcpi_last_data_sent; /* since last sent data. */ uint32_t tcpi_last_ack_sent; /* since last sent ack. */ uint32_t tcpi_last_data_recv; /* since last recv data. */ uint32_t tcpi_last_ack_recv; /* since last recv ack. */ /* Metrics; variable units. */ uint32_t __tcpi_pmtu; uint32_t __tcpi_rcv_ssthresh; uint32_t tcpi_rtt; /* Smoothed RTT in usecs. */ uint32_t tcpi_rttvar; /* RTT variance in usecs. */ uint32_t tcpi_snd_ssthresh; /* Slow start threshold. */ uint32_t tcpi_snd_cwnd; /* Send congestion window. */ uint32_t __tcpi_advmss; uint32_t __tcpi_reordering; uint32_t __tcpi_rcv_rtt; uint32_t tcpi_rcv_space; /* Advertised recv window. */ /* * Members below this point are only set if process is privileged, * otherwise values will be 0. */ /* FreeBSD/NetBSD extensions to tcp_info. */ uint32_t tcpi_snd_wnd; /* Advertised send window. */ uint32_t tcpi_snd_nxt; /* Next egress seqno */ uint32_t tcpi_rcv_nxt; /* Next ingress seqno */ uint32_t tcpi_toe_tid; /* HWTID for TOE endpoints */ uint32_t tcpi_snd_rexmitpack; /* Retransmitted packets */ uint32_t tcpi_rcv_ooopack; /* Out-of-order packets */ uint32_t tcpi_snd_zerowin; /* Zero-sized windows sent */ /* OpenBSD extensions */ uint32_t tcpi_rttmin; uint32_t tcpi_max_sndwnd; uint32_t tcpi_rcv_adv; uint32_t tcpi_rcv_up; uint32_t tcpi_snd_una; uint32_t tcpi_snd_up; uint32_t tcpi_snd_wl1; uint32_t tcpi_snd_wl2; uint32_t tcpi_snd_max; uint32_t tcpi_ts_recent; uint32_t tcpi_ts_recent_age; uint32_t tcpi_rfbuf_cnt; uint32_t tcpi_rfbuf_ts; uint32_t tcpi_so_rcv_sb_cc; uint32_t tcpi_so_rcv_sb_hiwat; uint32_t tcpi_so_rcv_sb_lowat; uint32_t tcpi_so_rcv_sb_wat; uint32_t tcpi_so_snd_sb_cc; uint32_t tcpi_so_snd_sb_hiwat; uint32_t tcpi_so_snd_sb_lowat; uint32_t tcpi_so_snd_sb_wat; }; #endif /* __BSD_VISIBLE */ /* * User-settable options (used with setsockopt). */ #define TCP_NODELAY 0x01 /* don't delay send to coalesce pkts */ #define TCP_MAXSEG 0x02 /* set maximum segment size */ #define TCP_MD5SIG 0x04 /* enable TCP MD5 signature option */ #define TCP_SACK_ENABLE 0x08 /* enable SACKs (if disabled by def.) */ #define TCP_INFO 0x09 /* retrieve tcp_info structure */ #define TCP_NOPUSH 0x10 /* don't push last block of write */ #endif /* _NETINET_TCP_H_ */
