/*
 * 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.
 */
#ifndef _LINUX_TCP_H
#define _LINUX_TCP_H

#include <linux/types.h>
#include <asm/byteorder.h>
#include <linux/socket.h>

struct tcphdr {
        __be16        source;
        __be16        dest;
        __be32        seq;
        __be32        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        
        __be16        window;
        __sum16        check;
        __be16        urg_ptr;
};

/*
 *        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;
        __be32                   words[5];
}; 

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

enum { 
        TCP_FLAG_CWR = __cpu_to_be32(0x00800000),
        TCP_FLAG_ECE = __cpu_to_be32(0x00400000),
        TCP_FLAG_URG = __cpu_to_be32(0x00200000),
        TCP_FLAG_ACK = __cpu_to_be32(0x00100000),
        TCP_FLAG_PSH = __cpu_to_be32(0x00080000),
        TCP_FLAG_RST = __cpu_to_be32(0x00040000),
        TCP_FLAG_SYN = __cpu_to_be32(0x00020000),
        TCP_FLAG_FIN = __cpu_to_be32(0x00010000),
        TCP_RESERVED_BITS = __cpu_to_be32(0x0F000000),
        TCP_DATA_OFFSET = __cpu_to_be32(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 TCP_CONGESTION                13        /* Congestion control algorithm */
#define TCP_MD5SIG                14        /* TCP MD5 Signature (RFC2385) */

#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;

        __u32        tcpi_rcv_rtt;
        __u32        tcpi_rcv_space;

        __u32        tcpi_total_retrans;
};

/* for TCP_MD5SIG socket option */
#define TCP_MD5SIG_MAXKEYLEN        80

struct tcp_md5sig {
        struct __kernel_sockaddr_storage tcpm_addr;        /* address associated */
        __u16        __tcpm_pad1;                                /* zero */
        __u16        tcpm_keylen;                                /* key length */
        __u32        __tcpm_pad2;                                /* zero */
        __u8        tcpm_key[TCP_MD5SIG_MAXKEYLEN];                /* key (binary) */
};


#endif        /* _LINUX_TCP_H */