include/linux/tcp.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for the TCP protocol.
   7  *
   8  * Version:     @(#)tcp.h       1.0.2   04/28/93
   9  *
  10  * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  */
  17 #ifndef _LINUX_TCP_H
  18 #define _LINUX_TCP_H
  19
  20 #include <linux/types.h>
  21 #include <asm/byteorder.h>
  22
  23 struct tcphdr {
  24         __u16   source;
  25         __u16   dest;
  26         __u32   seq;
  27         __u32   ack_seq;
  28 #if defined(__LITTLE_ENDIAN_BITFIELD)
  29         __u16   res1:4,
  30                 doff:4,
  31                 fin:1,
  32                 syn:1,
  33                 rst:1,
  34                 psh:1,
  35                 ack:1,
  36                 urg:1,
  37                 ece:1,
  38                 cwr:1;
  39 #elif defined(__BIG_ENDIAN_BITFIELD)
  40         __u16   doff:4,
  41                 res1:4,
  42                 cwr:1,
  43                 ece:1,
  44                 urg:1,
  45                 ack:1,
  46                 psh:1,
  47                 rst:1,
  48                 syn:1,
  49                 fin:1;
  50 #else
  51 #error  "Adjust your <asm/byteorder.h> defines"
  52 #endif
  53         __u16   window;
  54         __u16   check;
  55         __u16   urg_ptr;
  56 };
  57
  58
  59 enum {
  60   TCP_ESTABLISHED = 1,
  61   TCP_SYN_SENT,
  62   TCP_SYN_RECV,
  63   TCP_FIN_WAIT1,
  64   TCP_FIN_WAIT2,
  65   TCP_TIME_WAIT,
  66   TCP_CLOSE,
  67   TCP_CLOSE_WAIT,
  68   TCP_LAST_ACK,
  69   TCP_LISTEN,
  70   TCP_CLOSING,   /* now a valid state */
  71
  72   TCP_MAX_STATES /* Leave at the end! */
  73 };
  74
  75 #define TCP_STATE_MASK  0xF
  76 #define TCP_ACTION_FIN  (1 << 7)
  77
  78 enum {
  79   TCPF_ESTABLISHED = (1 << 1),
  80   TCPF_SYN_SENT  = (1 << 2),
  81   TCPF_SYN_RECV  = (1 << 3),
  82   TCPF_FIN_WAIT1 = (1 << 4),
  83   TCPF_FIN_WAIT2 = (1 << 5),
  84   TCPF_TIME_WAIT = (1 << 6),
  85   TCPF_CLOSE     = (1 << 7),
  86   TCPF_CLOSE_WAIT = (1 << 8),
  87   TCPF_LAST_ACK  = (1 << 9),
  88   TCPF_LISTEN    = (1 << 10),
  89   TCPF_CLOSING   = (1 << 11)
  90 };
  91
  92 /*
  93  *      The union cast uses a gcc extension to avoid aliasing problems
  94  *  (union is compatible to any of its members)
  95  *  This means this part of the code is -fstrict-aliasing safe now.
  96  */
  97 union tcp_word_hdr {
  98         struct tcphdr hdr;
  99         __u32             words[5];
 100 };
 101
 102 #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
 103
 104 enum {
 105         TCP_FLAG_CWR = __constant_htonl(0x00800000),
 106         TCP_FLAG_ECE = __constant_htonl(0x00400000),
 107         TCP_FLAG_URG = __constant_htonl(0x00200000),
 108         TCP_FLAG_ACK = __constant_htonl(0x00100000),
 109         TCP_FLAG_PSH = __constant_htonl(0x00080000),
 110         TCP_FLAG_RST = __constant_htonl(0x00040000),
 111         TCP_FLAG_SYN = __constant_htonl(0x00020000),
 112         TCP_FLAG_FIN = __constant_htonl(0x00010000),
 113         TCP_RESERVED_BITS = __constant_htonl(0x0FC00000),
 114         TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
 115 };
 116
 117 /* TCP socket options */
 118 #define TCP_NODELAY             1       /* Turn off Nagle's algorithm. */
 119 #define TCP_MAXSEG              2       /* Limit MSS */
 120 #define TCP_CORK                3       /* Never send partially complete segments */
 121 #define TCP_KEEPIDLE            4       /* Start keeplives after this period */
 122 #define TCP_KEEPINTVL           5       /* Interval between keepalives */
 123 #define TCP_KEEPCNT             6       /* Number of keepalives before death */
 124 #define TCP_SYNCNT              7       /* Number of SYN retransmits */
 125 #define TCP_LINGER2             8       /* Life time of orphaned FIN-WAIT-2 state */
 126 #define TCP_DEFER_ACCEPT        9       /* Wake up listener only when data arrive */
 127 #define TCP_WINDOW_CLAMP        10      /* Bound advertised window */
 128 #define TCP_INFO                11      /* Information about this connection. */
 129
 130 #define TCPI_OPT_TIMESTAMPS     1
 131 #define TCPI_OPT_SACK           2
 132 #define TCPI_OPT_WSCALE         4
 133 #define TCPI_OPT_ECN            8
 134
 135 enum tcp_ca_state
 136 {
 137         TCP_CA_Open = 0,
 138 #define TCPF_CA_Open    (1<<TCP_CA_Open)
 139         TCP_CA_Disorder = 1,
 140 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
 141         TCP_CA_CWR = 2,
 142 #define TCPF_CA_CWR     (1<<TCP_CA_CWR)
 143         TCP_CA_Recovery = 3,
 144 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
 145         TCP_CA_Loss = 4
 146 #define TCPF_CA_Loss    (1<<TCP_CA_Loss)
 147 };
 148
 149 struct tcp_info
 150 {
 151         __u8    tcpi_state;
 152         __u8    tcpi_ca_state;
 153         __u8    tcpi_retransmits;
 154         __u8    tcpi_probes;
 155         __u8    tcpi_backoff;
 156         __u8    tcpi_options;
 157         __u8    tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
 158
 159         __u32   tcpi_rto;
 160         __u32   tcpi_ato;
 161         __u32   tcpi_snd_mss;
 162         __u32   tcpi_rcv_mss;
 163
 164         __u32   tcpi_unacked;
 165         __u32   tcpi_sacked;
 166         __u32   tcpi_lost;
 167         __u32   tcpi_retrans;
 168         __u32   tcpi_fackets;
 169
 170         /* Times. */
 171         __u32   tcpi_last_data_sent;
 172         __u32   tcpi_last_ack_sent;     /* Not remembered, sorry. */
 173         __u32   tcpi_last_data_recv;
 174         __u32   tcpi_last_ack_recv;
 175
 176         /* Metrics. */
 177         __u32   tcpi_pmtu;
 178         __u32   tcpi_rcv_ssthresh;
 179         __u32   tcpi_rtt;
 180         __u32   tcpi_rttvar;
 181         __u32   tcpi_snd_ssthresh;
 182         __u32   tcpi_snd_cwnd;
 183         __u32   tcpi_advmss;
 184         __u32   tcpi_reordering;
 185 };
 186
 187 #endif  /* _LINUX_TCP_H */