/** @file
  TCP protocol header file.

  Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef _TCP_PROTO_H_
#define _TCP_PROTO_H_

///
/// Tcp states don't change their order. It is used as an
/// index to mTcpOutFlag and other macros.
///
#define TCP_CLOSED       0
#define TCP_LISTEN       1
#define TCP_SYN_SENT     2
#define TCP_SYN_RCVD     3
#define TCP_ESTABLISHED  4
#define TCP_FIN_WAIT_1   5
#define TCP_FIN_WAIT_2   6
#define TCP_CLOSING      7
#define TCP_TIME_WAIT    8
#define TCP_CLOSE_WAIT   9
#define TCP_LAST_ACK     10


///
/// Flags in the TCP header
///
#define TCP_FLG_FIN      0x01
#define TCP_FLG_SYN      0x02
#define TCP_FLG_RST      0x04
#define TCP_FLG_PSH      0x08
#define TCP_FLG_ACK      0x10
#define TCP_FLG_URG      0x20

 //
 // mask for all the flags
 //
#define TCP_FLG_FLAG     0x3F


#define TCP_CONNECT_REFUSED      (-1) ///< TCP error status
#define TCP_CONNECT_RESET        (-2) ///< TCP error status
#define TCP_CONNECT_CLOSED       (-3) ///< TCP error status

//
// Current congestion status as suggested by RFC3782.
//
#define TCP_CONGEST_RECOVER      1  ///< During the NewReno fast recovery.
#define TCP_CONGEST_LOSS         2  ///< Retxmit because of retxmit time out.
#define TCP_CONGEST_OPEN         3  ///< TCP is opening its congestion window.

//
// TCP control flags
//
#define TCP_CTRL_NO_NAGLE        0x0001 ///< Disable Nagle algorithm
#define TCP_CTRL_NO_KEEPALIVE    0x0002 ///< Disable keepalive timer.
#define TCP_CTRL_NO_WS           0x0004 ///< Disable window scale option.
#define TCP_CTRL_RCVD_WS         0x0008 ///< Received a wnd scale option in syn.
#define TCP_CTRL_NO_TS           0x0010 ///< Disable Timestamp option.
#define TCP_CTRL_RCVD_TS         0x0020 ///< Received a Timestamp option in syn.
#define TCP_CTRL_SND_TS          0x0040 ///< Send Timestamp option to remote.
#define TCP_CTRL_SND_URG         0x0080 ///< In urgent send mode.
#define TCP_CTRL_RCVD_URG        0x0100 ///< In urgent receive mode.
#define TCP_CTRL_SND_PSH         0x0200 ///< In PUSH send mode.
#define TCP_CTRL_FIN_SENT        0x0400 ///< FIN is sent.
#define TCP_CTRL_FIN_ACKED       0x0800 ///< FIN is ACKed.
#define TCP_CTRL_TIMER_ON        0x1000 ///< At least one of the timer is on.
#define TCP_CTRL_RTT_ON          0x2000 ///< The RTT measurement is on.
#define TCP_CTRL_ACK_NOW         0x4000 ///< Send the ACK now, don't delay.

//
// Timer related values
//
#define TCP_TIMER_CONNECT        0                  ///< Connection establishment timer.
#define TCP_TIMER_REXMIT         1                  ///< Retransmit timer.
#define TCP_TIMER_PROBE          2                  ///< Window probe timer.
#define TCP_TIMER_KEEPALIVE      3                  ///< Keepalive timer.
#define TCP_TIMER_FINWAIT2       4                  ///< FIN_WAIT_2 timer.
#define TCP_TIMER_2MSL           5                  ///< TIME_WAIT timer.
#define TCP_TIMER_NUMBER         6                  ///< The total number of the TCP timer.
#define TCP_TICK                 200                ///< Every TCP tick is 200ms.
#define TCP_TICK_HZ              5                  ///< The frequence of TCP tick.
#define TCP_RTT_SHIFT            3                  ///< SRTT & RTTVAR scaled by 8.
#define TCP_RTO_MIN              TCP_TICK_HZ        ///< The minium value of RTO.
#define TCP_RTO_MAX              (TCP_TICK_HZ * 60) ///< The maxium value of RTO.
#define TCP_FOLD_RTT             4                  ///< Timeout threshod to fold RTT.

//
// Default values for some timers
//
#define TCP_MAX_LOSS             12                          ///< Default max times to retxmit.
#define TCP_KEEPALIVE_IDLE_MIN   (TCP_TICK_HZ * 60 * 60 * 2) ///< First keepalive.
#define TCP_KEEPALIVE_PERIOD     (TCP_TICK_HZ * 60)
#define TCP_MAX_KEEPALIVE        8
#define TCP_FIN_WAIT2_TIME       (2 * TCP_TICK_HZ)
#define TCP_TIME_WAIT_TIME       (2 * TCP_TICK_HZ)
#define TCP_PAWS_24DAY           (24 * 24 * 60 * 60 * TCP_TICK_HZ)
#define TCP_CONNECT_TIME         (75 * TCP_TICK_HZ)

//
// The header space to be reserved before TCP data to accomodate :
// 60byte IP head + 60byte TCP head + link layer head
//
#define TCP_MAX_HEAD             192

//
// Value ranges for some control option
//
#define TCP_RCV_BUF_SIZE         (2 * 1024 * 1024)
#define TCP_RCV_BUF_SIZE_MIN     (8 * 1024)
#define TCP_SND_BUF_SIZE         (2 * 1024 * 1024)
#define TCP_SND_BUF_SIZE_MIN     (8 * 1024)
#define TCP_BACKLOG              10
#define TCP_BACKLOG_MIN          5
#define TCP_MAX_LOSS_MIN         6
#define TCP_CONNECT_TIME_MIN     (60 * TCP_TICK_HZ)
#define TCP_MAX_KEEPALIVE_MIN    4
#define TCP_KEEPALIVE_IDLE_MAX   (TCP_TICK_HZ * 60 * 60 * 4)
#define TCP_KEEPALIVE_PERIOD_MIN (TCP_TICK_HZ * 30)
#define TCP_FIN_WAIT2_TIME_MAX   (4 * TCP_TICK_HZ)
#define TCP_TIME_WAIT_TIME_MAX   (60 * TCP_TICK_HZ)

///
/// TCP_CONNECTED: both ends have synchronized their ISN.
///
#define TCP_CONNECTED(state)     ((state) > TCP_SYN_RCVD)

#define TCP_FIN_RCVD(State) \
  ( \
    ((State) == TCP_CLOSE_WAIT) || \
    ((State) == TCP_LAST_ACK) || \
    ((State) == TCP_CLOSING) || \
    ((State) == TCP_TIME_WAIT) \
  )

#define TCP_LOCAL_CLOSED(State) \
  ( \
    ((State) == TCP_FIN_WAIT_1) || \
    ((State) == TCP_FIN_WAIT_2) || \
    ((State) == TCP_CLOSING) || \
    ((State) == TCP_TIME_WAIT) || \
    ((State) == TCP_LAST_ACK) \
  )

//
// Get the TCP_SEG point from a net buffer's ProtoData.
//
#define TCPSEG_NETBUF(NBuf)     ((TCP_SEG *) ((NBuf)->ProtoData))

//
// Macros to compare sequence no
//
#define TCP_SEQ_LT(SeqA, SeqB)  ((INT32) ((SeqA) - (SeqB)) < 0)
#define TCP_SEQ_LEQ(SeqA, SeqB) ((INT32) ((SeqA) - (SeqB)) <= 0)
#define TCP_SEQ_GT(SeqA, SeqB)  ((INT32) ((SeqB) - (SeqA)) < 0)
#define TCP_SEQ_GEQ(SeqA, SeqB) ((INT32) ((SeqB) - (SeqA)) <= 0)

//
// TCP_SEQ_BETWEEN return whether b <= m <= e
//
#define TCP_SEQ_BETWEEN(b, m, e)    ((e) - (b) >= (m) - (b))

//
// TCP_SUB_SEQ returns Seq1 - Seq2. Make sure Seq1 >= Seq2
//
#define TCP_SUB_SEQ(Seq1, Seq2)     ((UINT32) ((Seq1) - (Seq2)))

//
// Check whether Flag is on
//
#define TCP_FLG_ON(Value, Flag)     ((BOOLEAN) (((Value) & (Flag)) != 0))
//
// Set and Clear operation on a Flag
//
#define TCP_SET_FLG(Value, Flag)    ((Value) |= (Flag))
#define TCP_CLEAR_FLG(Value, Flag)  ((Value) &= ~(Flag))

//
// Test whether two peers are equal
//
#define TCP_PEER_EQUAL(Pa, Pb, Ver) \
  (((Pa)->Port == (Pb)->Port) && TcpIsIpEqual(&((Pa)->Ip), &((Pb)->Ip), Ver))

//
// Test whether Pa matches Pb, or Pa is more specific
// than pb. Zero means wildcard.
//
#define TCP_PEER_MATCH(Pa, Pb, Ver) \
  ( \
    (((Pb)->Port == 0) || ((Pb)->Port == (Pa)->Port)) && \
    (TcpIsIpZero (&((Pb)->Ip), Ver) || TcpIsIpEqual (&((Pb)->Ip), &((Pa)->Ip), Ver)) \
  )

#define TCP_TIMER_ON(Flag, Timer)     ((Flag) & (1 << (Timer)))
#define TCP_SET_TIMER(Flag, Timer)    ((Flag) = (UINT16) ((Flag) | (1 << (Timer))))
#define TCP_CLEAR_TIMER(Flag, Timer)  ((Flag) = (UINT16) ((Flag) & (~(1 << (Timer)))))


#define TCP_TIME_LT(Ta, Tb)           ((INT32) ((Ta) - (Tb)) < 0)
#define TCP_TIME_LEQ(Ta, Tb)          ((INT32) ((Ta) - (Tb)) <= 0)
#define TCP_SUB_TIME(Ta, Tb)          ((UINT32) ((Ta) - (Tb)))

#define TCP_MAX_WIN                   0xFFFFU

///
/// TCP segmentation data.
///
typedef struct _TCP_SEG {
  TCP_SEQNO Seq;  ///< Starting sequence number.
  TCP_SEQNO End;  ///< The sequence of the last byte + 1, include SYN/FIN. End-Seq = SEG.LEN.
  TCP_SEQNO Ack;  ///< ACK field in the segment.
  UINT8     Flag; ///< TCP header flags.
  UINT16    Urg;  ///< Valid if URG flag is set.
  UINT32    Wnd;  ///< TCP window size field.
} TCP_SEG;

///
/// Network endpoint, IP plus Port structure.
///
typedef struct _TCP_PEER {
  EFI_IP_ADDRESS  Ip;     ///< IP address, in network byte order.
  TCP_PORTNO      Port;   ///< Port number, in network byte order.
} TCP_PEER;

typedef struct _TCP_CONTROL_BLOCK  TCP_CB;

///
/// TCP control block: it includes various states.
///
struct _TCP_CONTROL_BLOCK {
  LIST_ENTRY        List;     ///< Back and forward link entry
  TCP_CB            *Parent;  ///< The parent TCP_CB structure

  SOCKET            *Sk;      ///< The socket it controled.
  TCP_PEER          LocalEnd; ///< Local endpoint.
  TCP_PEER          RemoteEnd;///< Remote endpoint.

  LIST_ENTRY        SndQue;   ///< Retxmission queue.
  LIST_ENTRY        RcvQue;   ///< Reassemble queue.
  UINT32            CtrlFlag; ///< Control flags, such as NO_NAGLE.
  INT32             Error;    ///< Soft error status, such as TCP_CONNECT_RESET.

  //
  // RFC793 and RFC1122 defined variables
  //
  UINT8             State;      ///< TCP state, such as SYN_SENT, LISTEN.
  UINT8             DelayedAck; ///< Number of delayed ACKs.
  UINT16            HeadSum;    ///< Checksum of the fixed parts of pesudo
                                ///< header: Src IP, Dst IP, 0, Protocol,
                                ///< do not include the TCP length.

  TCP_SEQNO         Iss;        ///< Initial Sending Sequence.
  TCP_SEQNO         SndUna;     ///< First unacknowledged data.
  TCP_SEQNO         SndNxt;     ///< Next data sequence to send.
  TCP_SEQNO         SndPsh;     ///< Send PUSH point.
  TCP_SEQNO         SndUp;      ///< Send urgent point.
  UINT32            SndWnd;     ///< Window advertised by the remote peer.
  UINT32            SndWndMax;  ///< Max send window advertised by the peer.
  TCP_SEQNO         SndWl1;     ///< Seq number used for last window update.
  TCP_SEQNO         SndWl2;     ///< Ack no of last window update.
  UINT16            SndMss;     ///< Max send segment size.
  TCP_SEQNO         RcvNxt;     ///< Next sequence no to receive.
  UINT32            RcvWnd;     ///< Window advertised by the local peer.
  TCP_SEQNO         RcvWl2;     ///< The RcvNxt (or ACK) of last window update.
                                ///< It is necessary because of delayed ACK.

  TCP_SEQNO         RcvUp;                   ///< Urgent point;
  TCP_SEQNO         Irs;                     ///< Initial Receiving Sequence.
  UINT16            RcvMss;                  ///< Max receive segment size.
  UINT16            EnabledTimer;            ///< Which timer is currently enabled.
  UINT32            Timer[TCP_TIMER_NUMBER]; ///< When the timer will expire.
  INT32             NextExpire;  ///< Countdown offset for the nearest timer.
  UINT32            Idle;        ///< How long the connection is in idle.
  UINT32            ProbeTime;   ///< The time out value for current window prober.
  BOOLEAN           ProbeTimerOn;///< If TRUE, the probe time is on.

  //
  // RFC1323 defined variables, about window scale,
  // timestamp and PAWS
  //
  UINT8             SndWndScale;  ///< Wndscale received from the peer.
  UINT8             RcvWndScale;  ///< Wndscale used to scale local buffer.
  UINT32            TsRecent;     ///< TsRecent to echo to the remote peer.
  UINT32            TsRecentAge;  ///< When this TsRecent is updated.

  //
  // RFC2988 defined variables. about RTT measurement
  //
  TCP_SEQNO         RttSeq;     ///< The seq of measured segment now.
  UINT32            RttMeasure; ///< Currently measured RTT in heartbeats.
  UINT32            SRtt;       ///< Smoothed RTT, scaled by 8.
  UINT32            RttVar;     ///< RTT variance, scaled by 8.
  UINT32            Rto;        ///< Current RTO, not scaled.

  //
  // RFC2581, and 3782 variables.
  // Congestion control + NewReno fast recovery.
  //
  UINT32            CWnd;         ///< Sender's congestion window.
  UINT32            Ssthresh;     ///< Slow start threshold.
  TCP_SEQNO         Recover;      ///< Recover point for NewReno.
  UINT16            DupAck;       ///< Number of duplicate ACKs.
  UINT8             CongestState; ///< The current congestion state(RFC3782).
  UINT8             LossTimes;    ///< Number of retxmit timeouts in a row.
  TCP_SEQNO         LossRecover;  ///< Recover point for retxmit.

  //
  // RFC7323
  // Addressing Window Retraction for TCP Window Scale Option.
  //
  TCP_SEQNO         RetxmitSeqMax;       ///< Max Seq number in previous retransmission.

  //
  // configuration parameters, for EFI_TCP4_PROTOCOL specification
  //
  UINT32            KeepAliveIdle;   ///< Idle time before sending first probe.
  UINT32            KeepAlivePeriod; ///< Interval for subsequent keep alive probe.
  UINT8             MaxKeepAlive;    ///< Maxium keep alive probe times.
  UINT8             KeepAliveProbes; ///< The number of keep alive probe.
  UINT16            MaxRexmit;       ///< The maxium number of retxmit before abort.
  UINT32            FinWait2Timeout; ///< The FIN_WAIT_2 timeout.
  UINT32            TimeWaitTimeout; ///< The TIME_WAIT timeout.
  UINT32            ConnectTimeout;  ///< The connect establishment timeout.

  //
  // configuration for tcp provided by user
  //
  BOOLEAN           UseDefaultAddr;
  UINT8             Tos;
  UINT8             Ttl;
  EFI_IPv4_ADDRESS  SubnetMask;


  BOOLEAN           RemoteIpZero;   ///< RemoteEnd.Ip is ZERO when configured.
  IP_IO_IP_INFO     *IpInfo;        ///< Pointer reference to Ip used to send pkt
  UINT32            Tick;           ///< 1 tick = 200ms
};

#endif
