sys/netinet/tcp.h

   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_ */