tcpdef.h

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/*
 * INET     An implementation of the TCP/IP protocol suite for the LINUX
 *      operating system.  INET is implemented using the  BSD Socket
 *      interface as the means of communication with the user level.
 *
 *      Definitions for the TCP protocol.
 *
 * Version: @(#)tcp.h   1.0.2   04/28/93
 *
 * Author:  Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#pragma once

#include "linux.h"

struct tcphdr {
    __u16   source;
    __u16   dest;
    __u32   seq;
    __u32   ack_seq;
//#if defined(__LITTLE_ENDIAN_BITFIELD)
    __u16   res1:4,
        doff:4,
        fin:1,
        syn:1,
        rst:1,
        psh:1,
        ack:1,
        urg:1,
        ece:1,
        cwr:1;
/*#elif defined(__BIG_ENDIAN_BITFIELD)
    __u16   doff:4,
        res1:4,
        cwr:1,
        ece:1,
        urg:1,
        ack:1,
        psh:1,
        rst:1,
        syn:1,
        fin:1;
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif  */
    __u16   window;
    __u16   check;
    __u16   urg_ptr;
};


enum {
  TCP_ESTABLISHED = 1,
  TCP_SYN_SENT,
  TCP_SYN_RECV,
  TCP_FIN_WAIT1,
  TCP_FIN_WAIT2,
  TCP_TIME_WAIT,
  TCP_CLOSE,
  TCP_CLOSE_WAIT,
  TCP_LAST_ACK,
  TCP_LISTEN,
  TCP_CLOSING,   /* now a valid state */

  TCP_MAX_STATES /* Leave at the end! */
};

#define TCP_STATE_MASK  0xF
#define TCP_ACTION_FIN  (1 << 7)

enum {
  TCPF_ESTABLISHED = (1 << 1),
  TCPF_SYN_SENT  = (1 << 2),
  TCPF_SYN_RECV  = (1 << 3),
  TCPF_FIN_WAIT1 = (1 << 4),
  TCPF_FIN_WAIT2 = (1 << 5),
  TCPF_TIME_WAIT = (1 << 6),
  TCPF_CLOSE     = (1 << 7),
  TCPF_CLOSE_WAIT = (1 << 8),
  TCPF_LAST_ACK  = (1 << 9),
  TCPF_LISTEN    = (1 << 10),
  TCPF_CLOSING   = (1 << 11)
};

/*
 *  The union cast uses a gcc extension to avoid aliasing problems
 *  (union is compatible to any of its members)
 *  This means this part of the code is -fstrict-aliasing safe now.
 */
union tcp_word_hdr {
    struct tcphdr hdr;
    __u32         words[5];
};

#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])

enum {
    TCP_FLAG_CWR = 0x00800000, // __constant_htonl(0x00800000),
    TCP_FLAG_ECE = 0x00400000, //__constant_htonl(0x00400000),
    TCP_FLAG_URG = 0x00200000, //__constant_htonl(0x00200000),
    TCP_FLAG_ACK = 0x00100000, //__constant_htonl(0x00100000),
    TCP_FLAG_PSH = 0x00080000, //__constant_htonl(0x00080000),
    TCP_FLAG_RST = 0x00040000, //__constant_htonl(0x00040000),
    TCP_FLAG_SYN = 0x00020000, //__constant_htonl(0x00020000),
    TCP_FLAG_FIN = 0x00010000, //__constant_htonl(0x00010000),
    TCP_RESERVED_BITS = 0x0F000000, //__constant_htonl(0x0F000000),
    TCP_DATA_OFFSET = 0xF0000000, //__constant_htonl(0xF0000000)
};

/* TCP socket options */
#define TCP_NODELAY     1   /* Turn off Nagle's algorithm. */
#define TCP_MAXSEG      2   /* Limit MSS */
#define TCP_CORK        3   /* Never send partially complete segments */
#define TCP_KEEPIDLE        4   /* Start keeplives after this period */
#define TCP_KEEPINTVL       5   /* Interval between keepalives */
#define TCP_KEEPCNT     6   /* Number of keepalives before death */
#define TCP_SYNCNT      7   /* Number of SYN retransmits */
#define TCP_LINGER2     8   /* Life time of orphaned FIN-WAIT-2 state */
#define TCP_DEFER_ACCEPT    9   /* Wake up listener only when data arrive */
#define TCP_WINDOW_CLAMP    10  /* Bound advertised window */
#define TCP_INFO        11  /* Information about this connection. */
#define TCP_QUICKACK        12  /* Block/reenable quick acks */

#define TCPI_OPT_TIMESTAMPS 1
#define TCPI_OPT_SACK       2
#define TCPI_OPT_WSCALE     4
#define TCPI_OPT_ECN        8

enum tcp_ca_state
{
    TCP_CA_Open = 0,
#define TCPF_CA_Open    (1<<TCP_CA_Open)
    TCP_CA_Disorder = 1,
#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
    TCP_CA_CWR = 2,
#define TCPF_CA_CWR (1<<TCP_CA_CWR)
    TCP_CA_Recovery = 3,
#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
    TCP_CA_Loss = 4
#define TCPF_CA_Loss    (1<<TCP_CA_Loss)
};

struct tcp_info
{
    __u8    tcpi_state;
    __u8    tcpi_ca_state;
    __u8    tcpi_retransmits;
    __u8    tcpi_probes;
    __u8    tcpi_backoff;
    __u8    tcpi_options;
    __u8    tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;

    __u32   tcpi_rto;
    __u32   tcpi_ato;
    __u32   tcpi_snd_mss;
    __u32   tcpi_rcv_mss;

    __u32   tcpi_unacked;
    __u32   tcpi_sacked;
    __u32   tcpi_lost;
    __u32   tcpi_retrans;
    __u32   tcpi_fackets;

    /* Times. */
    __u32   tcpi_last_data_sent;
    __u32   tcpi_last_ack_sent;     /* Not remembered, sorry. */
    __u32   tcpi_last_data_recv;
    __u32   tcpi_last_ack_recv;

    /* Metrics. */
    __u32   tcpi_pmtu;
    __u32   tcpi_rcv_ssthresh;
    __u32   tcpi_rtt;
    __u32   tcpi_rttvar;
    __u32   tcpi_snd_ssthresh;
    __u32   tcpi_snd_cwnd;
    __u32   tcpi_advmss;
    __u32   tcpi_reordering;
};