edk2/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c

/** @file
  The implementation for Ping shell command.

  (C) Copyright 2015 Hewlett-Packard Development Company, L.P.<BR>
  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>

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

**/

#include "UefiShellNetwork1CommandsLib.h"

#define PING_IP4_COPY_ADDRESS(Dest, Src)  (CopyMem ((Dest), (Src), sizeof (EFI_IPv4_ADDRESS)))

UINT64  mCurrentTick = 0;

//
// Function templates to match the IPv4 and IPv6 commands that we use.
//
typedef
EFI_STATUS
(EFIAPI *PING_IPX_POLL)(
  IN VOID          *This
  );

typedef
EFI_STATUS
(EFIAPI *PING_IPX_TRANSMIT)(
  IN VOID          *This,
  IN VOID          *Token
  );

typedef
EFI_STATUS
(EFIAPI *PING_IPX_RECEIVE)(
  IN VOID          *This,
  IN VOID          *Token
  );

typedef
EFI_STATUS
(EFIAPI *PING_IPX_CANCEL)(
  IN VOID          *This,
  IN VOID          *Token OPTIONAL
  );

///
/// A set of pointers to either IPv6 or IPv4 functions.
/// Unknown which one to the ping command.
///
typedef struct {
  PING_IPX_TRANSMIT    Transmit;
  PING_IPX_RECEIVE     Receive;
  PING_IPX_CANCEL      Cancel;
  PING_IPX_POLL        Poll;
} PING_IPX_PROTOCOL;

typedef union {
  VOID    *RxData;
  VOID    *TxData;
} PING_PACKET;

//
// PING_IPX_COMPLETION_TOKEN
// structures are used for both transmit and receive operations.
// This version is IP-unaware.
//
typedef struct {
  EFI_EVENT      Event;
  EFI_STATUS     Status;
  PING_PACKET    Packet;
} PING_IPX_COMPLETION_TOKEN;

#pragma pack(1)
typedef struct _ICMPX_ECHO_REQUEST_REPLY {
  UINT8     Type;
  UINT8     Code;
  UINT16    Checksum;
  UINT16    Identifier;
  UINT16    SequenceNum;
  UINT32    TimeStamp;
  UINT8     Data[1];
} ICMPX_ECHO_REQUEST_REPLY;
#pragma pack()

typedef struct _PING_ICMP_TX_INFO {
  LIST_ENTRY                   Link;
  UINT16                       SequenceNum;
  UINT32                       TimeStamp;
  PING_IPX_COMPLETION_TOKEN    *Token;
} PING_ICMPX_TX_INFO;

#define DEFAULT_TIMEOUT       5000
#define MAX_SEND_NUMBER       10000
#define MAX_BUFFER_SIZE       32768
#define DEFAULT_TIMER_PERIOD  358049
#define ONE_SECOND            10000000
#define PING_IP_CHOICE_IP4    1
#define PING_IP_CHOICE_IP6    2
#define DEFAULT_SEND_COUNT    10
#define DEFAULT_BUFFER_SIZE   16
#define ICMP_V4_ECHO_REQUEST  0x8
#define ICMP_V4_ECHO_REPLY    0x0
#define STALL_1_MILLI_SECOND  1000

#define PING_PRIVATE_DATA_SIGNATURE  SIGNATURE_32 ('P', 'i', 'n', 'g')
typedef struct _PING_PRIVATE_DATA {
  UINT32                       Signature;
  EFI_HANDLE                   NicHandle;
  EFI_HANDLE                   IpChildHandle;
  EFI_EVENT                    Timer;

  UINT32                       TimerPeriod;
  UINT32                       RttTimerTick;
  EFI_EVENT                    RttTimer;

  EFI_STATUS                   Status;
  LIST_ENTRY                   TxList;
  UINT16                       RxCount;
  UINT16                       TxCount;
  UINT64                       RttSum;
  UINT64                       RttMin;
  UINT64                       RttMax;
  UINT32                       SequenceNum;

  UINT32                       SendNum;
  UINT32                       BufferSize;
  UINT32                       IpChoice;

  PING_IPX_PROTOCOL            ProtocolPointers;
  VOID                         *IpProtocol;
  UINT8                        SrcAddress[MAX (sizeof (EFI_IPv6_ADDRESS), sizeof (EFI_IPv4_ADDRESS))];
  UINT8                        DstAddress[MAX (sizeof (EFI_IPv6_ADDRESS), sizeof (EFI_IPv4_ADDRESS))];
  PING_IPX_COMPLETION_TOKEN    RxToken;
  UINT16                       FailedCount;
} PING_PRIVATE_DATA;

/**
  Calculate the internet checksum (see RFC 1071).

  @param[in] Packet  Buffer which contains the data to be checksummed.
  @param[in] Length  Length to be checksummed.

  @retval Checksum     Returns the 16 bit ones complement of
                       ones complement sum of 16 bit words
**/
UINT16
NetChecksum (
  IN UINT8   *Buffer,
  IN UINT32  Length
  )
{
  UINT32  Sum;
  UINT8   Odd;
  UINT16  *Packet;

  Packet = (UINT16 *)Buffer;

  Sum      = 0;
  Odd      = (UINT8)(Length & 1);
  Length >>= 1;
  while ((Length--) != 0) {
    Sum += *Packet++;
  }

  if (Odd != 0) {
    Sum += *(UINT8 *)Packet;
  }

  Sum = (Sum & 0xffff) + (Sum >> 16);

  //
  // in case above carried
  //
  Sum += Sum >> 16;

  return (UINT16)Sum;
}

/**
  Reads and returns the current value of register.
  In IA64, the register is the Interval Timer Vector (ITV).
  In X86(IA32/X64), the register is the Time Stamp Counter (TSC)

  @return The current value of the register.

**/

STATIC CONST SHELL_PARAM_ITEM  PingParamList[] = {
  {
    L"-l",
    TypeValue
  },
  {
    L"-n",
    TypeValue
  },
  {
    L"-s",
    TypeValue
  },
  {
    L"-_s",
    TypeValue
  },
  {
    L"-_ip6",
    TypeFlag
  },
  {
    NULL,
    TypeMax
  },
};

//
// Global Variables in Ping command.
//
STATIC CONST CHAR16  *mDstString;
STATIC CONST CHAR16  *mSrcString;

/**
  RTT timer tick routine.

  @param[in]    Event    A EFI_EVENT type event.
  @param[in]    Context  The pointer to Context.

**/
VOID
EFIAPI
RttTimerTickRoutine (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  UINT32  *RttTimerTick;

  RttTimerTick = (UINT32 *)Context;
  (*RttTimerTick)++;
}

/**
  Get the timer period of the system.

  This function tries to get the system timer period by creating
  an 1ms period timer.

  @return     System timer period in MS, or 0 if operation failed.

**/
UINT32
GetTimerPeriod (
  VOID
  )
{
  EFI_STATUS  Status;
  UINT32      RttTimerTick;
  EFI_EVENT   TimerEvent;
  UINT32      StallCounter;
  EFI_TPL     OldTpl;
  UINT32      TimerPeriod;

  RttTimerTick = 0;
  StallCounter = 0;
  TimerPeriod  = 0;

  Status = gBS->CreateEvent (
                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  RttTimerTickRoutine,
                  &RttTimerTick,
                  &TimerEvent
                  );
  if (EFI_ERROR (Status)) {
    return 0;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  Status = gBS->SetTimer (
                  TimerEvent,
                  TimerPeriodic,
                  TICKS_PER_MS
                  );
  if (EFI_ERROR (Status)) {
    gBS->CloseEvent (TimerEvent);
    return 0;
  }

  while (RttTimerTick < 10) {
    gBS->Stall (STALL_1_MILLI_SECOND);
    ++StallCounter;
  }

  gBS->RestoreTPL (OldTpl);

  gBS->SetTimer (TimerEvent, TimerCancel, 0);
  gBS->CloseEvent (TimerEvent);

  TimerPeriod = StallCounter / RttTimerTick;
  if (TimerPeriod != 0) {
    return TimerPeriod;
  } else {
    return 1;
  }
}

/**
  Initialize the timer event for RTT (round trip time).

  @param[in]    Private    The pointer to PING_PRIVATE_DATA.

  @retval EFI_SUCCESS      RTT timer is started.
  @retval Others           Failed to start the RTT timer.

**/
EFI_STATUS
PingInitRttTimer (
  PING_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS  Status;

  Private->TimerPeriod = GetTimerPeriod ();
  if (Private->TimerPeriod == 0) {
    return EFI_ABORTED;
  }

  Private->RttTimerTick = 0;
  Status                = gBS->CreateEvent (
                                 EVT_TIMER | EVT_NOTIFY_SIGNAL,
                                 TPL_NOTIFY,
                                 RttTimerTickRoutine,
                                 &Private->RttTimerTick,
                                 &Private->RttTimer
                                 );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = gBS->SetTimer (
                  Private->RttTimer,
                  TimerPeriodic,
                  TICKS_PER_MS
                  );
  if (EFI_ERROR (Status)) {
    gBS->CloseEvent (Private->RttTimer);
    return Status;
  }

  return EFI_SUCCESS;
}

/**
  Free RTT timer event resource.

  @param[in]    Private    The pointer to PING_PRIVATE_DATA.

**/
VOID
PingFreeRttTimer (
  PING_PRIVATE_DATA  *Private
  )
{
  if (Private->RttTimer != NULL) {
    gBS->SetTimer (Private->RttTimer, TimerCancel, 0);
    gBS->CloseEvent (Private->RttTimer);
  }
}

/**
  Read the current time.

  @param[in]    Private    The pointer to PING_PRIVATE_DATA.

  @retval the current tick value.
**/
UINT32
ReadTime (
  PING_PRIVATE_DATA  *Private
  )
{
  return Private->RttTimerTick;
}

/**
  Calculate a duration in ms.

  @param[in]    Private   The pointer to PING_PRIVATE_DATA.
  @param[in]    Begin     The start point of time.
  @param[in]    End       The end point of time.

  @return               The duration in ms.
  @retval 0             The parameters were not valid.
**/
UINT32
CalculateTick (
  PING_PRIVATE_DATA  *Private,
  IN UINT32          Begin,
  IN UINT32          End
  )
{
  if (End < Begin) {
    return (0);
  }

  return (End - Begin) * Private->TimerPeriod;
}

/**
  Destroy PING_ICMPX_TX_INFO, and recollect the memory.

  @param[in]    TxInfo    The pointer to PING_ICMPX_TX_INFO.
  @param[in]    IpChoice  Whether the token is IPv4 or IPv6
**/
VOID
PingDestroyTxInfo (
  IN PING_ICMPX_TX_INFO  *TxInfo,
  IN UINT32              IpChoice
  )
{
  EFI_IP6_TRANSMIT_DATA  *Ip6TxData;
  EFI_IP4_TRANSMIT_DATA  *Ip4TxData;
  EFI_IP6_FRAGMENT_DATA  *FragData;
  UINTN                  Index;

  if (TxInfo == NULL) {
    return;
  }

  if (TxInfo->Token != NULL) {
    if (TxInfo->Token->Event != NULL) {
      gBS->CloseEvent (TxInfo->Token->Event);
    }

    if (TxInfo->Token->Packet.TxData != NULL) {
      if (IpChoice == PING_IP_CHOICE_IP6) {
        Ip6TxData = TxInfo->Token->Packet.TxData;

        if (Ip6TxData->OverrideData != NULL) {
          FreePool (Ip6TxData->OverrideData);
        }

        if (Ip6TxData->ExtHdrs != NULL) {
          FreePool (Ip6TxData->ExtHdrs);
        }

        for (Index = 0; Index < Ip6TxData->FragmentCount; Index++) {
          FragData = Ip6TxData->FragmentTable[Index].FragmentBuffer;
          if (FragData != NULL) {
            FreePool (FragData);
          }
        }
      } else {
        Ip4TxData = TxInfo->Token->Packet.TxData;

        if (Ip4TxData->OverrideData != NULL) {
          FreePool (Ip4TxData->OverrideData);
        }

        for (Index = 0; Index < Ip4TxData->FragmentCount; Index++) {
          FragData = Ip4TxData->FragmentTable[Index].FragmentBuffer;
          if (FragData != NULL) {
            FreePool (FragData);
          }
        }
      }
    }

    FreePool (TxInfo->Token);
  }

  FreePool (TxInfo);
}

/**
  Match the request, and reply with SequenceNum/TimeStamp.

  @param[in]    Private    The pointer to PING_PRIVATE_DATA.
  @param[in]    Packet     The pointer to ICMPX_ECHO_REQUEST_REPLY.

  @retval EFI_SUCCESS      The match is successful.
  @retval EFI_NOT_FOUND    The reply can't be matched with any request.

**/
EFI_STATUS
Ping6MatchEchoReply (
  IN PING_PRIVATE_DATA         *Private,
  IN ICMPX_ECHO_REQUEST_REPLY  *Packet
  )
{
  PING_ICMPX_TX_INFO  *TxInfo;
  LIST_ENTRY          *Entry;
  LIST_ENTRY          *NextEntry;

  NET_LIST_FOR_EACH_SAFE (Entry, NextEntry, &Private->TxList) {
    TxInfo = BASE_CR (Entry, PING_ICMPX_TX_INFO, Link);

    if ((TxInfo->SequenceNum == Packet->SequenceNum) && (TxInfo->TimeStamp == Packet->TimeStamp)) {
      Private->RxCount++;
      RemoveEntryList (&TxInfo->Link);
      PingDestroyTxInfo (TxInfo, Private->IpChoice);
      return EFI_SUCCESS;
    }
  }

  return EFI_NOT_FOUND;
}

/**
  The original intention is to send a request.
  Currently, the application retransmits an icmp6 echo request packet
  per second in sendnumber times that is specified by the user.
  Because nothing can be done here, all things move to the timer routine.

  @param[in]    Event      A EFI_EVENT type event.
  @param[in]    Context    The pointer to Context.

**/
VOID
EFIAPI
Ping6OnEchoRequestSent (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
}

/**
  receive reply, match and print reply infomation.

  @param[in]    Event      A EFI_EVENT type event.
  @param[in]    Context    The pointer to context.

**/
VOID
EFIAPI
Ping6OnEchoReplyReceived (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  EFI_STATUS                Status;
  PING_PRIVATE_DATA         *Private;
  ICMPX_ECHO_REQUEST_REPLY  *Reply;
  UINT32                    PayLoad;
  UINT32                    Rtt;

  Private = (PING_PRIVATE_DATA *)Context;

  if ((Private == NULL) || (Private->Status == EFI_ABORTED) || (Private->Signature != PING_PRIVATE_DATA_SIGNATURE)) {
    return;
  }

  if (Private->RxToken.Packet.RxData == NULL) {
    return;
  }

  if (Private->IpChoice == PING_IP_CHOICE_IP6) {
    Reply   = ((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->FragmentTable[0].FragmentBuffer;
    PayLoad = ((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->DataLength;
    if (((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->Header->NextHeader != IP6_ICMP) {
      goto ON_EXIT;
    }

    if (!IP6_IS_MULTICAST ((EFI_IPv6_ADDRESS *)&Private->DstAddress) &&
        !EFI_IP6_EQUAL (&((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->Header->SourceAddress, (EFI_IPv6_ADDRESS *)&Private->DstAddress))
    {
      goto ON_EXIT;
    }

    if ((Reply->Type != ICMP_V6_ECHO_REPLY) || (Reply->Code != 0)) {
      goto ON_EXIT;
    }
  } else {
    Reply   = ((EFI_IP4_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->FragmentTable[0].FragmentBuffer;
    PayLoad = ((EFI_IP4_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->DataLength;
    if (!IP4_IS_MULTICAST (EFI_IP4 (*(EFI_IPv4_ADDRESS *)Private->DstAddress)) &&
        !EFI_IP4_EQUAL (&((EFI_IP4_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->Header->SourceAddress, (EFI_IPv4_ADDRESS *)&Private->DstAddress))
    {
      goto ON_EXIT;
    }

    if ((Reply->Type != ICMP_V4_ECHO_REPLY) || (Reply->Code != 0)) {
      goto ON_EXIT;
    }
  }

  if (PayLoad != Private->BufferSize) {
    goto ON_EXIT;
  }

  //
  // Check whether the reply matches the sent request before.
  //
  Status = Ping6MatchEchoReply (Private, Reply);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  //
  // Display statistics on this icmp6 echo reply packet.
  //
  Rtt = CalculateTick (Private, Reply->TimeStamp, ReadTime (Private));

  Private->RttSum += Rtt;
  Private->RttMin  = Private->RttMin > Rtt ? Rtt : Private->RttMin;
  Private->RttMax  = Private->RttMax < Rtt ? Rtt : Private->RttMax;

  ShellPrintHiiEx (
    -1,
    -1,
    NULL,
    STRING_TOKEN (STR_PING_REPLY_INFO),
    gShellNetwork1HiiHandle,
    PayLoad,
    mDstString,
    Reply->SequenceNum,
    Private->IpChoice == PING_IP_CHOICE_IP6 ? ((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->Header->HopLimit : 0,
    Rtt,
    Rtt + Private->TimerPeriod
    );

ON_EXIT:

  //
  // Recycle the packet before reusing RxToken
  //
  gBS->SignalEvent (Private->IpChoice == PING_IP_CHOICE_IP6 ? ((EFI_IP6_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->RecycleSignal : ((EFI_IP4_RECEIVE_DATA *)Private->RxToken.Packet.RxData)->RecycleSignal);

  if (Private->RxCount < Private->SendNum) {
    //
    // Continue to receive icmp echo reply packets.
    //
    Private->RxToken.Status = EFI_ABORTED;

    Status = Private->ProtocolPointers.Receive (Private->IpProtocol, &Private->RxToken);

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_RECEIVE), gShellNetwork1HiiHandle, Status);
      Private->Status = EFI_ABORTED;
    }
  } else {
    //
    // All reply have already been received from the dest host.
    //
    Private->Status = EFI_SUCCESS;
  }
}

/**
  Create a PING_IPX_COMPLETION_TOKEN.

  @param[in]    Private        The pointer of PING_PRIVATE_DATA.
  @param[in]    TimeStamp      The TimeStamp of request.
  @param[in]    SequenceNum    The SequenceNum of request.

  @return The pointer of PING_IPX_COMPLETION_TOKEN.

**/
PING_IPX_COMPLETION_TOKEN *
PingGenerateToken (
  IN PING_PRIVATE_DATA  *Private,
  IN UINT32             TimeStamp,
  IN UINT16             SequenceNum
  )
{
  EFI_STATUS                 Status;
  PING_IPX_COMPLETION_TOKEN  *Token;
  VOID                       *TxData;
  ICMPX_ECHO_REQUEST_REPLY   *Request;
  UINT16                     HeadSum;
  UINT16                     TempChecksum;

  Request = AllocateZeroPool (Private->BufferSize);
  if (Request == NULL) {
    return NULL;
  }

  TxData = AllocateZeroPool (Private->IpChoice == PING_IP_CHOICE_IP6 ? sizeof (EFI_IP6_TRANSMIT_DATA) : sizeof (EFI_IP4_TRANSMIT_DATA));
  if (TxData == NULL) {
    FreePool (Request);
    return NULL;
  }

  Token = AllocateZeroPool (sizeof (PING_IPX_COMPLETION_TOKEN));
  if (Token == NULL) {
    FreePool (Request);
    FreePool (TxData);
    return NULL;
  }

  //
  // Assembly echo request packet.
  //
  Request->Type        = (UINT8)(Private->IpChoice == PING_IP_CHOICE_IP6 ? ICMP_V6_ECHO_REQUEST : ICMP_V4_ECHO_REQUEST);
  Request->Code        = 0;
  Request->SequenceNum = SequenceNum;
  Request->Identifier  = 0;
  Request->Checksum    = 0;

  //
  // Assembly token for transmit.
  //
  if (Private->IpChoice == PING_IP_CHOICE_IP6) {
    Request->TimeStamp                                                 = TimeStamp;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->ExtHdrsLength                   = 0;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->ExtHdrs                         = NULL;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->OverrideData                    = 0;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->DataLength                      = Private->BufferSize;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->FragmentCount                   = 1;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->FragmentTable[0].FragmentBuffer = (VOID *)Request;
    ((EFI_IP6_TRANSMIT_DATA *)TxData)->FragmentTable[0].FragmentLength = Private->BufferSize;
  } else {
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->OptionsLength                   = 0;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->OptionsBuffer                   = NULL;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->OverrideData                    = 0;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->TotalDataLength                 = Private->BufferSize;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->FragmentCount                   = 1;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->FragmentTable[0].FragmentBuffer = (VOID *)Request;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->FragmentTable[0].FragmentLength = Private->BufferSize;
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->DestinationAddress.Addr[0]      = Private->DstAddress[0];
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->DestinationAddress.Addr[1]      = Private->DstAddress[1];
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->DestinationAddress.Addr[2]      = Private->DstAddress[2];
    ((EFI_IP4_TRANSMIT_DATA *)TxData)->DestinationAddress.Addr[3]      = Private->DstAddress[3];

    HeadSum            = NetChecksum ((UINT8 *)Request, Private->BufferSize);
    Request->TimeStamp = TimeStamp;
    TempChecksum       = NetChecksum ((UINT8 *)&Request->TimeStamp, sizeof (UINT64));
    Request->Checksum  = (UINT16)(~NetAddChecksum (HeadSum, TempChecksum));
  }

  Token->Status        = EFI_ABORTED;
  Token->Packet.TxData = TxData;

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  Ping6OnEchoRequestSent,
                  Private,
                  &Token->Event
                  );

  if (EFI_ERROR (Status)) {
    FreePool (Request);
    FreePool (TxData);
    FreePool (Token);
    return NULL;
  }

  return Token;
}

/**
  Transmit the PING_IPX_COMPLETION_TOKEN.

  @param[in]    Private    The pointer of PING_PRIVATE_DATA.

  @retval EFI_SUCCESS             Transmitted successfully.
  @retval EFI_OUT_OF_RESOURCES    No memory is available on the platform.
  @retval others                  Transmitted unsuccessfully.

**/
EFI_STATUS
PingSendEchoRequest (
  IN PING_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS          Status;
  PING_ICMPX_TX_INFO  *TxInfo;

  TxInfo = AllocateZeroPool (sizeof (PING_ICMPX_TX_INFO));

  if (TxInfo == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  TxInfo->TimeStamp   = ReadTime (Private);
  TxInfo->SequenceNum = (UINT16)(Private->TxCount + 1);
  TxInfo->Token       = PingGenerateToken (
                          Private,
                          TxInfo->TimeStamp,
                          TxInfo->SequenceNum
                          );

  if (TxInfo->Token == NULL) {
    PingDestroyTxInfo (TxInfo, Private->IpChoice);
    return EFI_OUT_OF_RESOURCES;
  }

  ASSERT (Private->ProtocolPointers.Transmit != NULL);

  InsertTailList (&Private->TxList, &TxInfo->Link);

  Status = Private->ProtocolPointers.Transmit (Private->IpProtocol, TxInfo->Token);

  if (EFI_ERROR (Status)) {
    RemoveEntryList (&TxInfo->Link);
    PingDestroyTxInfo (TxInfo, Private->IpChoice);
    return Status;
  }

  Private->TxCount++;

  return EFI_SUCCESS;
}

/**
  Place a completion token into the receive packet queue to receive the echo reply.

  @param[in]    Private    The pointer of PING_PRIVATE_DATA.

  @retval EFI_SUCCESS      Put the token into the receive packet queue successfully.
  @retval others           Put the token into the receive packet queue unsuccessfully.

**/
EFI_STATUS
Ping6ReceiveEchoReply (
  IN PING_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS  Status;

  ZeroMem (&Private->RxToken, sizeof (PING_IPX_COMPLETION_TOKEN));

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  Ping6OnEchoReplyReceived,
                  Private,
                  &Private->RxToken.Event
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  Private->RxToken.Status = EFI_NOT_READY;

  Status = Private->ProtocolPointers.Receive (Private->IpProtocol, &Private->RxToken);
  if (EFI_ERROR (Status)) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_RECEIVE), gShellNetwork1HiiHandle, Status);
  }

  return Status;
}

/**
  Remove the timeout request from the list.

  @param[in]    Event    A EFI_EVENT type event.
  @param[in]    Context  The pointer to Context.

**/
VOID
EFIAPI
Ping6OnTimerRoutine (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  EFI_STATUS          Status;
  PING_PRIVATE_DATA   *Private;
  PING_ICMPX_TX_INFO  *TxInfo;
  LIST_ENTRY          *Entry;
  LIST_ENTRY          *NextEntry;
  UINT64              Time;

  Private = (PING_PRIVATE_DATA *)Context;
  if (Private->Signature != PING_PRIVATE_DATA_SIGNATURE) {
    Private->Status = EFI_NOT_FOUND;
    return;
  }

  //
  // Retransmit icmp6 echo request packets per second in sendnumber times.
  //
  if (Private->TxCount < Private->SendNum) {
    Status = PingSendEchoRequest (Private);
    if (Private->TxCount != 0) {
      if (EFI_ERROR (Status)) {
        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_SEND_REQUEST), gShellNetwork1HiiHandle, Private->TxCount + 1);
      }
    }
  }

  //
  // Check whether any icmp6 echo request in the list timeout.
  //
  NET_LIST_FOR_EACH_SAFE (Entry, NextEntry, &Private->TxList) {
    TxInfo = BASE_CR (Entry, PING_ICMPX_TX_INFO, Link);
    Time   = CalculateTick (Private, TxInfo->TimeStamp, ReadTime (Private));

    //
    // Remove the timeout echo request from txlist.
    //
    if (Time > DEFAULT_TIMEOUT) {
      if (EFI_ERROR (TxInfo->Token->Status)) {
        Private->ProtocolPointers.Cancel (Private->IpProtocol, TxInfo->Token);
      }

      //
      // Remove the timeout icmp6 echo request from list.
      //
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_TIMEOUT), gShellNetwork1HiiHandle, TxInfo->SequenceNum);

      RemoveEntryList (&TxInfo->Link);
      PingDestroyTxInfo (TxInfo, Private->IpChoice);

      Private->RxCount++;
      Private->FailedCount++;

      if (IsListEmpty (&Private->TxList) && (Private->TxCount == Private->SendNum)) {
        //
        // All the left icmp6 echo request in the list timeout.
        //
        Private->Status = EFI_TIMEOUT;
      }
    }
  }
}

/**
  Determine if a IP4 address is Link Local.

  169.254.1.0 through 169.254.254.255 is link local.

  @param[in] Address  The address to test.

  @retval TRUE      It is.
  @retval FALSE     It is not.
**/
BOOLEAN
PingNetIp4IsLinkLocalAddr (
  IN CONST EFI_IPv4_ADDRESS  *Address
  )
{
  return ((BOOLEAN)(Address->Addr[0] == 169 && Address->Addr[1] == 254 && Address->Addr[2] >= 1 && Address->Addr[2] <= 254));
}

/**
  Determine if a IP4 address is unspecified.

  @param[in] Address  The address to test.

  @retval TRUE      It is.
  @retval FALSE     It is not.
**/
BOOLEAN
PingNetIp4IsUnspecifiedAddr (
  IN CONST EFI_IPv4_ADDRESS  *Address
  )
{
  return  ((BOOLEAN)((ReadUnaligned32 ((UINT32 *)&Address->Addr[0])) == 0x00000000));
}

/**
  Create a valid IP instance.

  @param[in]    Private    The pointer of PING_PRIVATE_DATA.

  @retval EFI_SUCCESS              Create a valid IPx instance successfully.
  @retval EFI_ABORTED              Locate handle with ipx service binding protocol unsuccessfully.
  @retval EFI_INVALID_PARAMETER    The source address is unspecified when the destination address is a link-local address.
  @retval EFI_OUT_OF_RESOURCES     No memory is available on the platform.
  @retval EFI_NOT_FOUND            The source address is not found.
**/
EFI_STATUS
PingCreateIpInstance (
  IN  PING_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS                    Status;
  UINTN                         HandleIndex;
  UINTN                         HandleNum;
  EFI_HANDLE                    *HandleBuffer;
  BOOLEAN                       UnspecifiedSrc;
  EFI_STATUS                    MediaStatus;
  EFI_SERVICE_BINDING_PROTOCOL  *EfiSb;
  VOID                          *IpXCfg;
  EFI_IP6_CONFIG_DATA           Ip6Config;
  EFI_IP4_CONFIG_DATA           Ip4Config;
  VOID                          *IpXInterfaceInfo;
  UINTN                         IfInfoSize;
  EFI_IPv6_ADDRESS              *Addr;
  UINTN                         AddrIndex;

  HandleBuffer     = NULL;
  UnspecifiedSrc   = FALSE;
  MediaStatus      = EFI_SUCCESS;
  EfiSb            = NULL;
  IpXInterfaceInfo = NULL;
  IfInfoSize       = 0;

  //
  // Locate all the handles with ip6 service binding protocol.
  //
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  Private->IpChoice == PING_IP_CHOICE_IP6 ? &gEfiIp6ServiceBindingProtocolGuid : &gEfiIp4ServiceBindingProtocolGuid,
                  NULL,
                  &HandleNum,
                  &HandleBuffer
                  );
  if (EFI_ERROR (Status) || (HandleNum == 0) || (HandleBuffer == NULL)) {
    return EFI_ABORTED;
  }

  if ((Private->IpChoice == PING_IP_CHOICE_IP6) ? NetIp6IsUnspecifiedAddr ((EFI_IPv6_ADDRESS *)&Private->SrcAddress) : \
      PingNetIp4IsUnspecifiedAddr ((EFI_IPv4_ADDRESS *)&Private->SrcAddress))
  {
    //
    // SrcAddress is unspecified. So, both connected and configured interface will be automatic selected.
    //
    UnspecifiedSrc = TRUE;
  }

  //
  // Source address is required when pinging a link-local address.
  //
  if (Private->IpChoice == PING_IP_CHOICE_IP6) {
    if (NetIp6IsLinkLocalAddr ((EFI_IPv6_ADDRESS *)&Private->DstAddress) && UnspecifiedSrc) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_INVALID_SOURCE), gShellNetwork1HiiHandle);
      Status = EFI_INVALID_PARAMETER;
      goto ON_ERROR;
    }
  } else {
    ASSERT (Private->IpChoice == PING_IP_CHOICE_IP4);
    if (PingNetIp4IsLinkLocalAddr ((EFI_IPv4_ADDRESS *)&Private->DstAddress) && UnspecifiedSrc) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_INVALID_SOURCE), gShellNetwork1HiiHandle);
      Status = EFI_INVALID_PARAMETER;
      goto ON_ERROR;
    }
  }

  //
  // For each ip6 protocol, check interface addresses list.
  //
  for (HandleIndex = 0; HandleIndex < HandleNum; HandleIndex++) {
    EfiSb            = NULL;
    IpXInterfaceInfo = NULL;
    IfInfoSize       = 0;

    if (UnspecifiedSrc) {
      //
      // Check media.
      //
      NetLibDetectMediaWaitTimeout (HandleBuffer[HandleIndex], 0, &MediaStatus);
      if (MediaStatus != EFI_SUCCESS) {
        //
        // Skip this one.
        //
        continue;
      }
    }

    Status = gBS->HandleProtocol (
                    HandleBuffer[HandleIndex],
                    Private->IpChoice == PING_IP_CHOICE_IP6 ? &gEfiIp6ServiceBindingProtocolGuid : &gEfiIp4ServiceBindingProtocolGuid,
                    (VOID **)&EfiSb
                    );
    if (EFI_ERROR (Status)) {
      goto ON_ERROR;
    }

    //
    // Ip6config protocol and ip6 service binding protocol are installed
    // on the same handle.
    //
    Status = gBS->HandleProtocol (
                    HandleBuffer[HandleIndex],
                    Private->IpChoice == PING_IP_CHOICE_IP6 ? &gEfiIp6ConfigProtocolGuid : &gEfiIp4Config2ProtocolGuid,
                    (VOID **)&IpXCfg
                    );

    if (EFI_ERROR (Status)) {
      goto ON_ERROR;
    }

    //
    // Get the interface information size.
    //
    if (Private->IpChoice == PING_IP_CHOICE_IP6) {
      Status = ((EFI_IP6_CONFIG_PROTOCOL *)IpXCfg)->GetData (
                                                      IpXCfg,
                                                      Ip6ConfigDataTypeInterfaceInfo,
                                                      &IfInfoSize,
                                                      NULL
                                                      );
    } else {
      Status = ((EFI_IP4_CONFIG2_PROTOCOL *)IpXCfg)->GetData (
                                                       IpXCfg,
                                                       Ip4Config2DataTypeInterfaceInfo,
                                                       &IfInfoSize,
                                                       NULL
                                                       );
    }

    //
    // Skip the ones not in current use.
    //
    if (Status == EFI_NOT_STARTED) {
      continue;
    }

    if (Status != EFI_BUFFER_TOO_SMALL) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_GETDATA), gShellNetwork1HiiHandle, Status);
      goto ON_ERROR;
    }

    IpXInterfaceInfo = AllocateZeroPool (IfInfoSize);

    if (IpXInterfaceInfo == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto ON_ERROR;
    }

    //
    // Get the interface info.
    //
    if (Private->IpChoice == PING_IP_CHOICE_IP6) {
      Status = ((EFI_IP6_CONFIG_PROTOCOL *)IpXCfg)->GetData (
                                                      IpXCfg,
                                                      Ip6ConfigDataTypeInterfaceInfo,
                                                      &IfInfoSize,
                                                      IpXInterfaceInfo
                                                      );
    } else {
      Status = ((EFI_IP4_CONFIG2_PROTOCOL *)IpXCfg)->GetData (
                                                       IpXCfg,
                                                       Ip4Config2DataTypeInterfaceInfo,
                                                       &IfInfoSize,
                                                       IpXInterfaceInfo
                                                       );
    }

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_GETDATA), gShellNetwork1HiiHandle, Status);
      goto ON_ERROR;
    }

    //
    // Check whether the source address is one of the interface addresses.
    //
    if (Private->IpChoice == PING_IP_CHOICE_IP6) {
      for (AddrIndex = 0; AddrIndex < ((EFI_IP6_CONFIG_INTERFACE_INFO *)IpXInterfaceInfo)->AddressInfoCount; AddrIndex++) {
        Addr = &(((EFI_IP6_CONFIG_INTERFACE_INFO *)IpXInterfaceInfo)->AddressInfo[AddrIndex].Address);

        if (UnspecifiedSrc) {
          if (!NetIp6IsUnspecifiedAddr (Addr) && !NetIp6IsLinkLocalAddr (Addr)) {
            //
            // Select the interface automatically.
            //
            CopyMem (&Private->SrcAddress, Addr, sizeof (Private->SrcAddress));
            break;
          }
        } else if (EFI_IP6_EQUAL (&Private->SrcAddress, Addr)) {
          //
          // Match a certain interface address.
          //
          break;
        }
      }

      if (AddrIndex < ((EFI_IP6_CONFIG_INTERFACE_INFO *)IpXInterfaceInfo)->AddressInfoCount) {
        //
        // Found a nic handle with right interface address.
        //
        break;
      }
    } else {
      if (UnspecifiedSrc) {
        if (!PingNetIp4IsUnspecifiedAddr (&((EFI_IP4_CONFIG2_INTERFACE_INFO *)IpXInterfaceInfo)->StationAddress) &&
            !PingNetIp4IsLinkLocalAddr (&((EFI_IP4_CONFIG2_INTERFACE_INFO *)IpXInterfaceInfo)->StationAddress))
        {
          //
          // Select the interface automatically.
          //
          break;
        }
      } else if (EFI_IP4_EQUAL (&Private->SrcAddress, &((EFI_IP4_CONFIG2_INTERFACE_INFO *)IpXInterfaceInfo)->StationAddress)) {
        //
        // Match a certain interface address.
        //
        break;
      }
    }

    FreePool (IpXInterfaceInfo);
    IpXInterfaceInfo = NULL;
  }

  //
  // No exact interface address matched.
  //

  if (HandleIndex == HandleNum) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_CONFIGD_NIC_NF), gShellNetwork1HiiHandle, L"ping");
    Status = EFI_NOT_FOUND;
    goto ON_ERROR;
  }

  Private->NicHandle = HandleBuffer[HandleIndex];

  ASSERT (EfiSb != NULL);
  Status = EfiSb->CreateChild (EfiSb, &Private->IpChildHandle);

  if (EFI_ERROR (Status)) {
    goto ON_ERROR;
  }

  if (Private->IpChoice == PING_IP_CHOICE_IP6) {
    Status = gBS->OpenProtocol (
                    Private->IpChildHandle,
                    &gEfiIp6ProtocolGuid,
                    &Private->IpProtocol,
                    gImageHandle,
                    Private->IpChildHandle,
                    EFI_OPEN_PROTOCOL_GET_PROTOCOL
                    );
    if (EFI_ERROR (Status)) {
      goto ON_ERROR;
    }

    ZeroMem (&Ip6Config, sizeof (EFI_IP6_CONFIG_DATA));

    //
    // Configure the ip6 instance for icmp6 packet exchange.
    //
    Ip6Config.DefaultProtocol   = 58;
    Ip6Config.AcceptAnyProtocol = FALSE;
    Ip6Config.AcceptIcmpErrors  = TRUE;
    Ip6Config.AcceptPromiscuous = FALSE;
    Ip6Config.TrafficClass      = 0;
    Ip6Config.HopLimit          = 128;
    Ip6Config.FlowLabel         = 0;
    Ip6Config.ReceiveTimeout    = 0;
    Ip6Config.TransmitTimeout   = 0;

    IP6_COPY_ADDRESS (&Ip6Config.StationAddress, &Private->SrcAddress);
    IP6_COPY_ADDRESS (&Ip6Config.DestinationAddress, &Private->DstAddress);

    Status = ((EFI_IP6_PROTOCOL *)(Private->IpProtocol))->Configure (Private->IpProtocol, &Ip6Config);

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_CONFIG), gShellNetwork1HiiHandle, Status);
      goto ON_ERROR;
    }

    Private->ProtocolPointers.Transmit = (PING_IPX_TRANSMIT)((EFI_IP6_PROTOCOL *)Private->IpProtocol)->Transmit;
    Private->ProtocolPointers.Receive  = (PING_IPX_RECEIVE)((EFI_IP6_PROTOCOL *)Private->IpProtocol)->Receive;
    Private->ProtocolPointers.Cancel   = (PING_IPX_CANCEL)((EFI_IP6_PROTOCOL *)Private->IpProtocol)->Cancel;
    Private->ProtocolPointers.Poll     = (PING_IPX_POLL)((EFI_IP6_PROTOCOL *)Private->IpProtocol)->Poll;
  } else {
    Status = gBS->OpenProtocol (
                    Private->IpChildHandle,
                    &gEfiIp4ProtocolGuid,
                    &Private->IpProtocol,
                    gImageHandle,
                    Private->IpChildHandle,
                    EFI_OPEN_PROTOCOL_GET_PROTOCOL
                    );
    if (EFI_ERROR (Status)) {
      goto ON_ERROR;
    }

    ZeroMem (&Ip4Config, sizeof (EFI_IP4_CONFIG_DATA));

    //
    // Configure the ip4 instance for icmp4 packet exchange.
    //
    Ip4Config.DefaultProtocol   = 1;
    Ip4Config.AcceptAnyProtocol = FALSE;
    Ip4Config.AcceptBroadcast   = FALSE;
    Ip4Config.AcceptIcmpErrors  = TRUE;
    Ip4Config.AcceptPromiscuous = FALSE;
    Ip4Config.DoNotFragment     = FALSE;
    Ip4Config.RawData           = FALSE;
    Ip4Config.ReceiveTimeout    = 0;
    Ip4Config.TransmitTimeout   = 0;
    Ip4Config.UseDefaultAddress = TRUE;
    Ip4Config.TimeToLive        = 128;
    Ip4Config.TypeOfService     = 0;

    Status = ((EFI_IP4_PROTOCOL *)(Private->IpProtocol))->Configure (Private->IpProtocol, &Ip4Config);

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_CONFIG), gShellNetwork1HiiHandle, Status);
      goto ON_ERROR;
    }

    Private->ProtocolPointers.Transmit = (PING_IPX_TRANSMIT)((EFI_IP4_PROTOCOL *)Private->IpProtocol)->Transmit;
    Private->ProtocolPointers.Receive  = (PING_IPX_RECEIVE)((EFI_IP4_PROTOCOL *)Private->IpProtocol)->Receive;
    Private->ProtocolPointers.Cancel   = (PING_IPX_CANCEL)((EFI_IP4_PROTOCOL *)Private->IpProtocol)->Cancel;
    Private->ProtocolPointers.Poll     = (PING_IPX_POLL)((EFI_IP4_PROTOCOL *)Private->IpProtocol)->Poll;
  }

  if (HandleBuffer != NULL) {
    FreePool (HandleBuffer);
  }

  return EFI_SUCCESS;

ON_ERROR:
  if (HandleBuffer != NULL) {
    FreePool (HandleBuffer);
  }

  if (IpXInterfaceInfo != NULL) {
    FreePool (IpXInterfaceInfo);
  }

  if ((EfiSb != NULL) && (Private->IpChildHandle != NULL)) {
    EfiSb->DestroyChild (EfiSb, Private->IpChildHandle);
  }

  return Status;
}

/**
  Destroy the IP instance.

  @param[in]    Private    The pointer of PING_PRIVATE_DATA.

**/
VOID
Ping6DestroyIp6Instance (
  IN PING_PRIVATE_DATA  *Private
  )
{
  EFI_STATUS                    Status;
  EFI_SERVICE_BINDING_PROTOCOL  *IpSb;

  gBS->CloseProtocol (
         Private->IpChildHandle,
         Private->IpChoice == PING_IP_CHOICE_IP6 ? &gEfiIp6ProtocolGuid : &gEfiIp4ProtocolGuid,
         gImageHandle,
         Private->IpChildHandle
         );

  Status = gBS->HandleProtocol (
                  Private->NicHandle,
                  Private->IpChoice == PING_IP_CHOICE_IP6 ? &gEfiIp6ServiceBindingProtocolGuid : &gEfiIp4ServiceBindingProtocolGuid,
                  (VOID **)&IpSb
                  );

  if (!EFI_ERROR (Status)) {
    IpSb->DestroyChild (IpSb, Private->IpChildHandle);
  }
}

/**
  The Ping Process.

  @param[in]   SendNumber     The send request count.
  @param[in]   BufferSize     The send buffer size.
  @param[in]   SrcAddress     The source address.
  @param[in]   DstAddress     The destination address.
  @param[in]   IpChoice       The choice between IPv4 and IPv6.

  @retval SHELL_SUCCESS  The ping processed successfullly.
  @retval others         The ping processed unsuccessfully.
**/
SHELL_STATUS
ShellPing (
  IN UINT32            SendNumber,
  IN UINT32            BufferSize,
  IN EFI_IPv6_ADDRESS  *SrcAddress,
  IN EFI_IPv6_ADDRESS  *DstAddress,
  IN UINT32            IpChoice
  )
{
  EFI_STATUS          Status;
  PING_PRIVATE_DATA   *Private;
  PING_ICMPX_TX_INFO  *TxInfo;
  LIST_ENTRY          *Entry;
  LIST_ENTRY          *NextEntry;
  SHELL_STATUS        ShellStatus;

  ShellStatus = SHELL_SUCCESS;
  Private     = AllocateZeroPool (sizeof (PING_PRIVATE_DATA));

  if (Private == NULL) {
    return (SHELL_OUT_OF_RESOURCES);
  }

  Private->IpChoice   = IpChoice;
  Private->Signature  = PING_PRIVATE_DATA_SIGNATURE;
  Private->SendNum    = SendNumber;
  Private->BufferSize = BufferSize;
  Private->RttMin     = ~((UINT64)(0x0));
  Private->Status     = EFI_NOT_READY;

  CopyMem (&Private->SrcAddress, SrcAddress, sizeof (Private->SrcAddress));
  CopyMem (&Private->DstAddress, DstAddress, sizeof (Private->DstAddress));

  InitializeListHead (&Private->TxList);

  //
  // Open and configure a ip instance for us.
  //
  Status = PingCreateIpInstance (Private);

  if (EFI_ERROR (Status)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    goto ON_EXIT;
  }

  //
  // Print the command line itself.
  //
  ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_START), gShellNetwork1HiiHandle, mDstString, Private->BufferSize);
  //
  // Create a ipv6 token to receive the first icmp6 echo reply packet.
  //
  Status = Ping6ReceiveEchoReply (Private);

  if (EFI_ERROR (Status)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    goto ON_EXIT;
  }

  //
  // Create and start timer to send icmp6 echo request packet per second.
  //
  Status = gBS->CreateEvent (
                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  Ping6OnTimerRoutine,
                  Private,
                  &Private->Timer
                  );

  if (EFI_ERROR (Status)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    goto ON_EXIT;
  }

  //
  // Start a timer to calculate the RTT.
  //
  Status = PingInitRttTimer (Private);
  if (EFI_ERROR (Status)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    goto ON_EXIT;
  }

  //
  // Create a ipv6 token to send the first icmp6 echo request packet.
  //
  Status = PingSendEchoRequest (Private);
  //
  // EFI_NOT_READY for IPsec is enable and IKE is not established.
  //
  if (EFI_ERROR (Status) && (Status != EFI_NOT_READY)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    if (Status == EFI_NOT_FOUND) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_NOSOURCE_INDO), gShellNetwork1HiiHandle, mDstString);
    } else if (Status == RETURN_NO_MAPPING) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_NOROUTE_FOUND), gShellNetwork1HiiHandle, mDstString, mSrcString);
    } else {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_PING_NETWORK_ERROR), gShellNetwork1HiiHandle, L"ping", Status);
    }

    goto ON_EXIT;
  }

  Status = gBS->SetTimer (
                  Private->Timer,
                  TimerPeriodic,
                  ONE_SECOND
                  );

  if (EFI_ERROR (Status)) {
    ShellStatus = SHELL_ACCESS_DENIED;
    goto ON_EXIT;
  }

  //
  // Control the ping6 process by two factors:
  // 1. Hot key
  // 2. Private->Status
  //   2.1. success means all icmp6 echo request packets get reply packets.
  //   2.2. timeout means the last icmp6 echo reply request timeout to get reply.
  //   2.3. noready means ping6 process is on-the-go.
  //
  while (Private->Status == EFI_NOT_READY) {
    Status = Private->ProtocolPointers.Poll (Private->IpProtocol);
    if (ShellGetExecutionBreakFlag ()) {
      Private->Status = EFI_ABORTED;
      goto ON_STAT;
    }
  }

ON_STAT:
  //
  // Display the statistics in all.
  //
  gBS->SetTimer (Private->Timer, TimerCancel, 0);

  if (Private->TxCount != 0) {
    ShellPrintHiiEx (
      -1,
      -1,
      NULL,
      STRING_TOKEN (STR_PING_STAT),
      gShellNetwork1HiiHandle,
      Private->TxCount,
      (Private->RxCount - Private->FailedCount),
      (100 - ((100 * (Private->RxCount - Private->FailedCount)) / Private->TxCount)),
      Private->RttSum
      );
  }

  if (Private->RxCount > Private->FailedCount) {
    ShellPrintHiiEx (
      -1,
      -1,
      NULL,
      STRING_TOKEN (STR_PING_RTT),
      gShellNetwork1HiiHandle,
      Private->RttMin,
      Private->RttMin + Private->TimerPeriod,
      Private->RttMax,
      Private->RttMax + Private->TimerPeriod,
      DivU64x64Remainder (Private->RttSum, (Private->RxCount - Private->FailedCount), NULL),
      DivU64x64Remainder (Private->RttSum, (Private->RxCount - Private->FailedCount), NULL) + Private->TimerPeriod
      );
  }

ON_EXIT:

  if (Private != NULL) {
    NET_LIST_FOR_EACH_SAFE (Entry, NextEntry, &Private->TxList) {
      TxInfo = BASE_CR (Entry, PING_ICMPX_TX_INFO, Link);

      if ((Private->IpProtocol != NULL) && (Private->ProtocolPointers.Cancel != NULL)) {
        Status = Private->ProtocolPointers.Cancel (Private->IpProtocol, TxInfo->Token);
      }

      RemoveEntryList (&TxInfo->Link);
      PingDestroyTxInfo (TxInfo, Private->IpChoice);
    }

    PingFreeRttTimer (Private);

    if (Private->Timer != NULL) {
      gBS->CloseEvent (Private->Timer);
    }

    if ((Private->IpProtocol != NULL) && (Private->ProtocolPointers.Cancel != NULL)) {
      Status = Private->ProtocolPointers.Cancel (Private->IpProtocol, &Private->RxToken);
    }

    if (Private->RxToken.Event != NULL) {
      gBS->CloseEvent (Private->RxToken.Event);
    }

    if (Private->IpChildHandle != NULL) {
      Ping6DestroyIp6Instance (Private);
    }

    FreePool (Private);
  }

  return ShellStatus;
}

/**
  Function for 'ping' command.

  @param[in] ImageHandle  Handle to the Image (NULL if Internal).
  @param[in] SystemTable  Pointer to the System Table (NULL if Internal).

  @retval SHELL_SUCCESS  The ping processed successfullly.
  @retval others         The ping processed unsuccessfully.

**/
SHELL_STATUS
EFIAPI
ShellCommandRunPing (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS        Status;
  SHELL_STATUS      ShellStatus;
  EFI_IPv6_ADDRESS  DstAddress;
  EFI_IPv6_ADDRESS  SrcAddress;
  UINT64            BufferSize;
  UINTN             SendNumber;
  LIST_ENTRY        *ParamPackage;
  CONST CHAR16      *ValueStr;
  UINTN             NonOptionCount;
  UINT32            IpChoice;
  CHAR16            *ProblemParam;

  //
  // we use IPv6 buffers to hold items...
  // make sure this is enough space!
  //
  ASSERT (sizeof (EFI_IPv4_ADDRESS) <= sizeof (EFI_IPv6_ADDRESS));
  ASSERT (sizeof (EFI_IP4_COMPLETION_TOKEN) <= sizeof (EFI_IP6_COMPLETION_TOKEN));

  IpChoice = PING_IP_CHOICE_IP4;

  ShellStatus  = SHELL_SUCCESS;
  ProblemParam = NULL;

  Status = ShellCommandLineParseEx (PingParamList, &ParamPackage, &ProblemParam, TRUE, FALSE);
  if (EFI_ERROR (Status)) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellNetwork1HiiHandle, L"ping", ProblemParam);
    ShellStatus = SHELL_INVALID_PARAMETER;
    goto ON_EXIT;
  }

  if (ShellCommandLineGetFlag (ParamPackage, L"-_ip6")) {
    IpChoice = PING_IP_CHOICE_IP6;
  }

  //
  // Parse the parameter of count number.
  //
  ValueStr = ShellCommandLineGetValue (ParamPackage, L"-n");
  if (ValueStr != NULL) {
    SendNumber = ShellStrToUintn (ValueStr);

    //
    // ShellStrToUintn will return 0 when input is 0 or an invalid input string.
    //
    if ((SendNumber == 0) || (SendNumber > MAX_SEND_NUMBER)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellNetwork1HiiHandle, L"ping", ValueStr);
      ShellStatus = SHELL_INVALID_PARAMETER;
      goto ON_EXIT;
    }
  } else {
    SendNumber = DEFAULT_SEND_COUNT;
  }

  //
  // Parse the parameter of buffer size.
  //
  ValueStr = ShellCommandLineGetValue (ParamPackage, L"-l");
  if (ValueStr != NULL) {
    BufferSize = ShellStrToUintn (ValueStr);

    //
    // ShellStrToUintn will return 0 when input is 0 or an invalid input string.
    //
    if ((BufferSize < 16) || (BufferSize > MAX_BUFFER_SIZE)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellNetwork1HiiHandle, L"ping", ValueStr);
      ShellStatus = SHELL_INVALID_PARAMETER;
      goto ON_EXIT;
    }
  } else {
    BufferSize = DEFAULT_BUFFER_SIZE;
  }

  ZeroMem (&SrcAddress, sizeof (EFI_IPv6_ADDRESS));
  ZeroMem (&DstAddress, sizeof (EFI_IPv6_ADDRESS));

  //
  // Parse the parameter of source ip address.
  //
  ValueStr = ShellCommandLineGetValue (ParamPackage, L"-s");
  if (ValueStr == NULL) {
    ValueStr = ShellCommandLineGetValue (ParamPackage, L"-_s");
  }

  if (ValueStr != NULL) {
    mSrcString = ValueStr;
    if (IpChoice == PING_IP_CHOICE_IP6) {
      Status = NetLibStrToIp6 (ValueStr, &SrcAddress);
    } else {
      Status = NetLibStrToIp4 (ValueStr, (EFI_IPv4_ADDRESS *)&SrcAddress);
    }

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellNetwork1HiiHandle, L"ping", ValueStr);
      ShellStatus = SHELL_INVALID_PARAMETER;
      goto ON_EXIT;
    }
  }

  //
  // Parse the parameter of destination ip address.
  //
  NonOptionCount = ShellCommandLineGetCount (ParamPackage);
  if (NonOptionCount < 2) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_FEW), gShellNetwork1HiiHandle, L"ping");
    ShellStatus = SHELL_INVALID_PARAMETER;
    goto ON_EXIT;
  }

  if (NonOptionCount > 2) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_MANY), gShellNetwork1HiiHandle, L"ping");
    ShellStatus = SHELL_INVALID_PARAMETER;
    goto ON_EXIT;
  }

  ValueStr = ShellCommandLineGetRawValue (ParamPackage, 1);
  if (ValueStr != NULL) {
    mDstString = ValueStr;
    if (IpChoice == PING_IP_CHOICE_IP6) {
      Status = NetLibStrToIp6 (ValueStr, &DstAddress);
    } else {
      Status = NetLibStrToIp4 (ValueStr, (EFI_IPv4_ADDRESS *)&DstAddress);
    }

    if (EFI_ERROR (Status)) {
      ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellNetwork1HiiHandle, L"ping", ValueStr);
      ShellStatus = SHELL_INVALID_PARAMETER;
      goto ON_EXIT;
    }
  }

  //
  // Enter into ping process.
  //
  ShellStatus = ShellPing (
                  (UINT32)SendNumber,
                  (UINT32)BufferSize,
                  &SrcAddress,
                  &DstAddress,
                  IpChoice
                  );

ON_EXIT:
  ShellCommandLineFreeVarList (ParamPackage);
  return ShellStatus;
}