audk/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c

/** @file

Copyright (c) 2007 - 2008, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

Module Name:

  PxeBcImpl.c

Abstract:

  Interface routines for PxeBc


**/


#include "PxeBcImpl.h"

/**
  Get and record the arp cache

  @param  This                    Pointer to EFI_PXE_BC_PROTOCOL

  @retval EFI_SUCCESS             Arp cache updated successfully
  @retval others                  If error occurs when updating arp cache

**/
STATIC
EFI_STATUS
UpdateArpCache (
  IN EFI_PXE_BASE_CODE_PROTOCOL     * This
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_STATUS              Status;
  UINT32                  EntryLength;
  UINT32                  EntryCount;
  EFI_ARP_FIND_DATA       *Entries;
  UINT32                  Index;

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  Status = Private->Arp->Find (Private->Arp, TRUE, NULL, &EntryLength, &EntryCount, &Entries, TRUE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Mode->ArpCacheEntries = MIN (EntryCount, EFI_PXE_BASE_CODE_MAX_ARP_ENTRIES);
  for (Index = 0; Index < Mode->ArpCacheEntries; Index ++) {
    CopyMem (&Mode->ArpCache[Index].IpAddr, Entries + 1, Entries->SwAddressLength);
    CopyMem (&Mode->ArpCache[Index].MacAddr, (UINT8 *)(Entries + 1) + Entries->SwAddressLength, Entries->HwAddressLength);
    //
    // Slip to the next FindData.
    //
    Entries = (EFI_ARP_FIND_DATA *)((UINT8 *)Entries + EntryLength);
  }

  return EFI_SUCCESS;
}

/**
  Timeout routine to catch arp cache.

  @param  Event              Pointer to EFI_PXE_BC_PROTOCOL
  @param  Context            Context of the timer event

**/
STATIC
VOID
EFIAPI
ArpCacheUpdateTimeout (
  IN EFI_EVENT    Event,
  IN VOID         *Context
  )
{
  UpdateArpCache ((EFI_PXE_BASE_CODE_PROTOCOL *) Context);
}

/**
  Timeout routine to catch arp cache.

  @param  Event                    Pointer to EFI_PXE_BC_PROTOCOL
  @param  Context

**/
STATIC
BOOLEAN
FindInArpCache (
  EFI_PXE_BASE_CODE_MODE    *PxeBcMode,
  EFI_IPv4_ADDRESS          *Ip4Addr,
  EFI_MAC_ADDRESS           *MacAddress
  )
{
  UINT32                  Index;

  for (Index = 0; Index < PxeBcMode->ArpCacheEntries; Index ++) {
    if (EFI_IP4_EQUAL (&PxeBcMode->ArpCache[Index].IpAddr.v4, Ip4Addr)) {
      CopyMem (MacAddress, &PxeBcMode->ArpCache[Index].MacAddr, sizeof (EFI_MAC_ADDRESS));
      return TRUE;
    }
  }

  return FALSE;
}

/**
  Notify function for the ICMP receive token, used to process
  the received ICMP packets.

  @param  Context               The context passed in by the event notifier.

  @return None.

**/
STATIC
VOID
EFIAPI
IcmpErrorListenHandlerDpc (
  IN VOID      *Context
  )
{
  EFI_STATUS              Status;
  EFI_IP4_RECEIVE_DATA    *RxData;
  EFI_IP4_PROTOCOL        *Ip4;
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  UINTN                   Index;
  UINT32                  CopiedLen;
  UINT8                   *CopiedPointer;

  Private = (PXEBC_PRIVATE_DATA *) Context;
  Mode    = &Private->Mode;
  Status  = Private->IcmpErrorRcvToken.Status;
  RxData  = Private->IcmpErrorRcvToken.Packet.RxData;
  Ip4     = Private->Ip4;

  if (EFI_ABORTED == Status) {
    //
    // The reception is actively aborted by the consumer, directly return.
    //
    return;
  }

  if ((EFI_SUCCESS != Status) || (NULL == RxData)) {
    //
    // Only process the normal packets and the icmp error packets, if RxData is NULL
    // with Status == EFI_SUCCESS or EFI_ICMP_ERROR, just resume the receive although
    // this should be a bug of the low layer (IP).
    //
    goto Resume;
  }

  if ((EFI_IP4 (RxData->Header->SourceAddress) != 0) &&
    !Ip4IsUnicast (EFI_NTOHL (RxData->Header->SourceAddress), 0)) {
    //
    // The source address is not zero and it's not a unicast IP address, discard it.
    //
    goto CleanUp;
  }

  if (!EFI_IP4_EQUAL (&RxData->Header->DestinationAddress, &Mode->StationIp.v4)) {
    //
    // The dest address is not equal to Station Ip address, discard it.
    //
    goto CleanUp;
  }

  //
  // Constructor ICMP error packet
  //
  CopiedLen = 0;
  CopiedPointer = (UINT8 *) &Mode->IcmpError;

  for (Index = 0; Index < RxData->FragmentCount; Index ++) {
    CopiedLen += RxData->FragmentTable[Index].FragmentLength;
    if (CopiedLen <= sizeof (EFI_PXE_BASE_CODE_ICMP_ERROR)) {
      CopyMem (CopiedPointer, RxData->FragmentTable[Index].FragmentBuffer, RxData->FragmentTable[Index].FragmentLength);
    } else {
      CopyMem (CopiedPointer, RxData->FragmentTable[Index].FragmentBuffer, CopiedLen - sizeof (EFI_PXE_BASE_CODE_ICMP_ERROR));
    }
    CopiedPointer += CopiedLen;
  }

  goto Resume;

CleanUp:
  gBS->SignalEvent (RxData->RecycleSignal);

Resume:
  Ip4->Receive (Ip4, &(Private->IcmpErrorRcvToken));
}

/**
  Request IcmpErrorListenHandlerDpc as a DPC at TPL_CALLBACK

  @param  Event                 The event signaled.
  @param  Context               The context passed in by the event notifier.

  @return None.

**/
STATIC
VOID
EFIAPI
IcmpErrorListenHandler (
  IN EFI_EVENT Event,
  IN VOID      *Context
  )
{
  //
  // Request IpIoListenHandlerDpc as a DPC at TPL_CALLBACK
  //
  NetLibQueueDpc (TPL_CALLBACK, IcmpErrorListenHandlerDpc, Context);
}

/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  UseIpv6                                     GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_ALREADY_STARTED                         GC_NOTO: Add description for
                                                      return value
  @retval EFI_UNSUPPORTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_SUCCESS                                 GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcStart (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN BOOLEAN                          UseIpv6
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_STATUS              Status;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (Mode->Started) {
    return EFI_ALREADY_STARTED;
  }

  if (UseIpv6) {
    //
    // IPv6 is not supported now.
    //
    return EFI_UNSUPPORTED;
  }

  //
  // Configure the udp4 instance to let it receive data
  //
  Status = Private->Udp4Read->Configure (Private->Udp4Read, &Private->Udp4CfgData);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Private->AddressIsOk = FALSE;

  ZeroMem (Mode, sizeof (EFI_PXE_BASE_CODE_MODE));

  Mode->Started = TRUE;
  Mode->TTL     = DEFAULT_TTL;
  Mode->ToS     = DEFAULT_ToS;
  Mode->AutoArp = TRUE;

  //
  // Create the event for Arp Cache checking.
  //
  Status = gBS->CreateEvent (
                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  ArpCacheUpdateTimeout,
                  This,
                  &Private->GetArpCacheEvent
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  //
  // Start the timeout timer event.
  //
  Status = gBS->SetTimer (
                  Private->GetArpCacheEvent,
                  TimerPeriodic,
                  TICKS_PER_SECOND
                  );

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

  //
  // Create ICMP error receiving event
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  IcmpErrorListenHandler,
                  Private,
                  &(Private->IcmpErrorRcvToken.Event)
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Status = Private->Ip4->Configure (Private->Ip4, &Private->Ip4ConfigData);
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  //
  // start to listen incoming packet
  //
  Status = Private->Ip4->Receive (Private->Ip4, &Private->IcmpErrorRcvToken);
  if (!EFI_ERROR (Status)) {
    return Status;
  }

ON_EXIT:
  Private->Ip4->Configure (Private->Ip4, NULL);

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

  if (Private->GetArpCacheEvent != NULL) {
    gBS->SetTimer (Private->GetArpCacheEvent, TimerCancel, 0);
    gBS->CloseEvent (Private->GetArpCacheEvent);
  }

  Mode->Started = FALSE;
  Mode->TTL     = 0;
  Mode->ToS     = 0;
  Mode->AutoArp = FALSE;

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_SUCCESS                                 GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcStop (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  Private->Ip4->Cancel (Private->Ip4, NULL);
  //
  // Dispatch the DPCs queued by the NotifyFunction of the canceled rx token's
  // events.
  //
  NetLibDispatchDpc ();

  Private->Ip4->Configure (Private->Ip4, NULL);

  //
  // Close the ICMP error receiving event.
  //
  gBS->CloseEvent (Private->IcmpErrorRcvToken.Event);

  //
  // Cancel the TimeoutEvent timer.
  //
  gBS->SetTimer (Private->GetArpCacheEvent, TimerCancel, 0);

  //
  // Close the TimeoutEvent event.
  //
  gBS->CloseEvent (Private->GetArpCacheEvent);

  Mode->Started = FALSE;

  Private->CurrentUdpSrcPort = 0;
  Private->Udp4Write->Configure (Private->Udp4Write, NULL);
  Private->Udp4Read->Configure (Private->Udp4Read, NULL);

  Private->Dhcp4->Stop (Private->Dhcp4);
  Private->Dhcp4->Configure (Private->Dhcp4, NULL);

  Private->FileSize = 0;

  return EFI_SUCCESS;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  SortOffers                                  GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcDhcp (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN BOOLEAN                          SortOffers
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_DHCP4_PROTOCOL      *Dhcp4;
  EFI_DHCP4_CONFIG_DATA   Dhcp4CfgData;
  EFI_DHCP4_MODE_DATA     Dhcp4Mode;
  EFI_DHCP4_PACKET_OPTION *OptList[PXEBC_DHCP4_MAX_OPTION_NUM];
  UINT32                  OptCount;
  UINT32                  DiscoverTimeout;
  UINTN                   Index;
  EFI_STATUS              Status;
  EFI_ARP_CONFIG_DATA     ArpConfigData;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status              = EFI_SUCCESS;
  Private             = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode                = Private->PxeBc.Mode;
  Dhcp4               = Private->Dhcp4;
  Private->Function   = EFI_PXE_BASE_CODE_FUNCTION_DHCP;
  Private->SortOffers = SortOffers;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  Mode->IcmpErrorReceived = FALSE;

  //
  // Initialize the DHCP options and build the option list
  //
  OptCount = PxeBcBuildDhcpOptions (Private, OptList, TRUE);

  //
  // Set the DHCP4 config data.
  //
  ZeroMem (&Dhcp4CfgData, sizeof (EFI_DHCP4_CONFIG_DATA));
  Dhcp4CfgData.OptionCount      = OptCount;
  Dhcp4CfgData.OptionList       = OptList;
  Dhcp4CfgData.Dhcp4Callback    = PxeBcDhcpCallBack;
  Dhcp4CfgData.CallbackContext  = Private;
  Dhcp4CfgData.DiscoverTryCount = 1;
  Dhcp4CfgData.DiscoverTimeout  = &DiscoverTimeout;

  for (Index = 0; Index < PXEBC_DHCP4_DISCOVER_RETRIES; Index++) {
    //
    // The four discovery timeouts are 4, 8, 16, 32 seconds respectively.
    //
    DiscoverTimeout = (PXEBC_DHCP4_DISCOVER_INIT_TIMEOUT << Index);

    Status          = Dhcp4->Configure (Dhcp4, &Dhcp4CfgData);
    if (EFI_ERROR (Status)) {
      break;
    }
    //
    // Zero those arrays to record the varies numbers of DHCP OFFERS.
    //
    Private->NumOffers   = 0;
    Private->BootpIndex  = 0;
    ZeroMem (Private->ServerCount, sizeof (Private->ServerCount));
    ZeroMem (Private->ProxyIndex, sizeof (Private->ProxyIndex));

    Status = Dhcp4->Start (Dhcp4, NULL);
    if (EFI_ERROR (Status)) {
      if (Status == EFI_TIMEOUT) {
        //
        // If no response is received or all received offers don't match
        // the PXE boot requirements, EFI_TIMEOUT will be returned.
        //
        continue;
      }
      if (Status == EFI_ICMP_ERROR) {
        Mode->IcmpErrorReceived = TRUE;
      }
      //
      // Other error status means the DHCP really fails.
      //
      break;
    }

    Status = Dhcp4->GetModeData (Dhcp4, &Dhcp4Mode);
    if (EFI_ERROR (Status)) {
      break;
    }

    ASSERT (Dhcp4Mode.State == Dhcp4Bound);

    CopyMem (&Private->StationIp, &Dhcp4Mode.ClientAddress, sizeof (EFI_IPv4_ADDRESS));
    CopyMem (&Private->SubnetMask, &Dhcp4Mode.SubnetMask, sizeof (EFI_IPv4_ADDRESS));
    CopyMem (&Private->GatewayIp, &Dhcp4Mode.RouterAddress, sizeof (EFI_IPv4_ADDRESS));

    //
    // Check the selected offer to see whether BINL is required, if no or BINL is
    // finished, set the various Mode members.
    //
    Status = PxeBcCheckSelectedOffer (Private);
    if (!EFI_ERROR (Status)) {
      break;
    }
  }

  if (EFI_ERROR (Status)) {
    Dhcp4->Stop (Dhcp4);
    Dhcp4->Configure (Dhcp4, NULL);
  } else {
    //
    // Remove the previously configured option list and callback function
    //
    ZeroMem (&Dhcp4CfgData, sizeof (EFI_DHCP4_CONFIG_DATA));
    Dhcp4->Configure (Dhcp4, &Dhcp4CfgData);

    Private->AddressIsOk = TRUE;

    if (!Mode->UsingIpv6) {
      //
      // If in IPv4 mode, configure the corresponding ARP with this new
      // station IP address.
      //
      ZeroMem (&ArpConfigData, sizeof (EFI_ARP_CONFIG_DATA));

      ArpConfigData.SwAddressType   = 0x0800;
      ArpConfigData.SwAddressLength = sizeof (EFI_IPv4_ADDRESS);
      ArpConfigData.StationAddress  = &Private->StationIp.v4;

      Private->Arp->Configure (Private->Arp, NULL);
      Private->Arp->Configure (Private->Arp, &ArpConfigData);

      //
      // Updated the route table. Fill the first entry.
      //
      Mode->RouteTableEntries                = 1;
      Mode->RouteTable[0].IpAddr.Addr[0]     = Private->StationIp.Addr[0] & Private->SubnetMask.Addr[0];
      Mode->RouteTable[0].SubnetMask.Addr[0] = Private->SubnetMask.Addr[0];
      Mode->RouteTable[0].GwAddr.Addr[0]     = 0;

      //
      // Create the default route entry if there is a default router.
      //
      if (Private->GatewayIp.Addr[0] != 0) {
        Mode->RouteTableEntries                = 2;
        Mode->RouteTable[1].IpAddr.Addr[0]     = 0;
        Mode->RouteTable[1].SubnetMask.Addr[0] = 0;
        Mode->RouteTable[1].GwAddr.Addr[0]     = Private->GatewayIp.Addr[0];
      }
    }
  }

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  Type                                        GC_NOTO: add argument
                                                      description
  @param  Layer                                       GC_NOTO: add argument
                                                      description
  @param  UseBis                                      GC_NOTO: add argument
                                                      description
  @param  Info                                        GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcDiscover (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN UINT16                           Type,
  IN UINT16                           *Layer,
  IN BOOLEAN                          UseBis,
  IN EFI_PXE_BASE_CODE_DISCOVER_INFO  *Info   OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA              *Private;
  EFI_PXE_BASE_CODE_MODE          *Mode;
  EFI_PXE_BASE_CODE_DISCOVER_INFO DefaultInfo;
  EFI_PXE_BASE_CODE_SRVLIST       *SrvList;
  EFI_PXE_BASE_CODE_SRVLIST       DefaultSrvList;
  PXEBC_CACHED_DHCP4_PACKET       *Packet;
  PXEBC_VENDOR_OPTION            *VendorOpt;
  UINT16                          Index;
  EFI_STATUS                      Status;
  PXEBC_BOOT_SVR_ENTRY            *BootSvrEntry;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Private           = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode              = Private->PxeBc.Mode;
  BootSvrEntry      = NULL;
  SrvList           = NULL;
  Status            = EFI_DEVICE_ERROR;
  Private->Function = EFI_PXE_BASE_CODE_FUNCTION_DISCOVER;

  if (!Private->AddressIsOk) {
    return EFI_INVALID_PARAMETER;
  }

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  Mode->IcmpErrorReceived = FALSE;

  //
  // If layer isn't EFI_PXE_BASE_CODE_BOOT_LAYER_INITIAL,
  //   use the previous setting;
  // If info isn't offered,
  //   use the cached DhcpAck and ProxyOffer packets.
  //
  if (*Layer != EFI_PXE_BASE_CODE_BOOT_LAYER_INITIAL) {

    if (!Mode->PxeDiscoverValid || !Mode->PxeReplyReceived || (!Mode->PxeBisReplyReceived && UseBis)) {

      return EFI_INVALID_PARAMETER;
    }

    DefaultInfo.IpCnt                 = 1;
    DefaultInfo.UseUCast              = TRUE;

    DefaultSrvList.Type               = Type;
    DefaultSrvList.AcceptAnyResponse  = FALSE;
    DefaultSrvList.IpAddr.Addr[0]     = Private->ServerIp.Addr[0];

    SrvList = &DefaultSrvList;
    Info = &DefaultInfo;
  } else if (Info == NULL) {
    //
    // Create info by the cached packet before
    //
    Packet    = (Mode->ProxyOfferReceived) ? &Private->ProxyOffer : &Private->Dhcp4Ack;
    VendorOpt = &Packet->PxeVendorOption;

    if (!Mode->DhcpAckReceived || !IS_VALID_DISCOVER_VENDOR_OPTION (VendorOpt->BitMap)) {
      //
      // Address is not acquired or no discovery options.
      //
      return EFI_INVALID_PARAMETER;
    }

    DefaultInfo.UseMCast    = (BOOLEAN)!IS_DISABLE_MCAST_DISCOVER (VendorOpt->DiscoverCtrl);
    DefaultInfo.UseBCast    = (BOOLEAN)!IS_DISABLE_BCAST_DISCOVER (VendorOpt->DiscoverCtrl);
    DefaultInfo.MustUseList = (BOOLEAN) IS_ENABLE_USE_SERVER_LIST (VendorOpt->DiscoverCtrl);
    DefaultInfo.UseUCast    = DefaultInfo.MustUseList;

    if (DefaultInfo.UseMCast) {
      //
      // Get the multicast discover ip address from vendor option.
      //
      CopyMem (&DefaultInfo.ServerMCastIp.Addr, &VendorOpt->DiscoverMcastIp, sizeof (EFI_IPv4_ADDRESS));
    }

    DefaultInfo.IpCnt = 0;

    if (DefaultInfo.MustUseList) {
      BootSvrEntry  = VendorOpt->BootSvr;
      Status        = EFI_INVALID_PARAMETER;

      while (((UINT8) (BootSvrEntry - VendorOpt->BootSvr)) < VendorOpt->BootSvrLen) {

        if (BootSvrEntry->Type == HTONS (Type)) {
          Status = EFI_SUCCESS;
          break;
        }

        BootSvrEntry = GET_NEXT_BOOT_SVR_ENTRY (BootSvrEntry);
      }

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

      DefaultInfo.IpCnt = BootSvrEntry->IpCnt;
    }

    Info = &DefaultInfo;
  } else {

    SrvList = Info->SrvList;

    if (!SrvList[0].AcceptAnyResponse) {

      for (Index = 1; Index < Info->IpCnt; Index++) {
        if (SrvList[Index].AcceptAnyResponse) {
          break;
        }
      }

      if (Index != Info->IpCnt) {
        return EFI_INVALID_PARAMETER;
      }
    }
  }

  if ((!Info->UseUCast && !Info->UseBCast && !Info->UseMCast) || (Info->MustUseList && Info->IpCnt == 0)) {

    return EFI_INVALID_PARAMETER;
  }
  //
  // Execute discover by UniCast/BroadCast/MultiCast
  //
  if (Info->UseUCast) {

    for (Index = 0; Index < Info->IpCnt; Index++) {

      if (BootSvrEntry == NULL) {
        Private->ServerIp.Addr[0] = SrvList[Index].IpAddr.Addr[0];
      } else {
        CopyMem (&Private->ServerIp, &BootSvrEntry->IpAddr[Index], sizeof (EFI_IPv4_ADDRESS));
      }

      Status = PxeBcDiscvBootService (
                Private,
                Type,
                Layer,
                UseBis,
                &SrvList[Index].IpAddr,
                0,
                NULL,
                TRUE,
                &Private->PxeReply.Packet.Ack
                );
    }

  } else if (Info->UseMCast) {

    Status = PxeBcDiscvBootService (
              Private,
              Type,
              Layer,
              UseBis,
              &Info->ServerMCastIp,
              0,
              NULL,
              TRUE,
              &Private->PxeReply.Packet.Ack
              );

  } else if (Info->UseBCast) {

    Status = PxeBcDiscvBootService (
              Private,
              Type,
              Layer,
              UseBis,
              NULL,
              Info->IpCnt,
              SrvList,
              TRUE,
              &Private->PxeReply.Packet.Ack
              );
  }

  if (EFI_ERROR (Status) || !Mode->PxeReplyReceived || (!Mode->PxeBisReplyReceived && UseBis)) {
    if (Status == EFI_ICMP_ERROR) {
      Mode->IcmpErrorReceived = TRUE;
    } else {
      Status = EFI_DEVICE_ERROR;
    }
  } else {
    PxeBcParseCachedDhcpPacket (&Private->PxeReply);
  }

  if (Mode->PxeBisReplyReceived) {
    CopyMem (&Private->ServerIp, &Mode->PxeReply.Dhcpv4.BootpSiAddr, sizeof (EFI_IPv4_ADDRESS));
  }

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  Operation                                   GC_NOTO: add argument
                                                      description
  @param  BufferPtr                                   GC_NOTO: add argument
                                                      description
  @param  Overwrite                                   GC_NOTO: add argument
                                                      description
  @param  BufferSize                                  GC_NOTO: add argument
                                                      description
  @param  BlockSize                                   GC_NOTO: add argument
                                                      description
  @param  ServerIp                                    GC_NOTO: add argument
                                                      description
  @param  Filename                                    GC_NOTO: add argument
                                                      description
  @param  Info                                        GC_NOTO: add argument
                                                      description
  @param  DontUseBuffer                               GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcMtftp (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN EFI_PXE_BASE_CODE_TFTP_OPCODE    Operation,
  IN OUT VOID                         *BufferPtr,
  IN BOOLEAN                          Overwrite,
  IN OUT UINT64                       *BufferSize,
  IN UINTN                            *BlockSize    OPTIONAL,
  IN EFI_IP_ADDRESS                   *ServerIp,
  IN UINT8                            *Filename,
  IN EFI_PXE_BASE_CODE_MTFTP_INFO     *Info         OPTIONAL,
  IN BOOLEAN                          DontUseBuffer
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_MTFTP4_CONFIG_DATA  Mtftp4Config;
  EFI_STATUS              Status;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_MAC_ADDRESS         TempMacAddr;

  if ((This == NULL) ||
      (Filename == NULL) ||
      (BufferSize == NULL) ||
      ((ServerIp == NULL) || !Ip4IsUnicast (NTOHL (ServerIp->Addr[0]), 0)) ||
      ((BufferPtr == NULL) && DontUseBuffer) ||
      ((BlockSize != NULL) && (*BlockSize < 512))) {

    return EFI_INVALID_PARAMETER;
  }

  Status  = EFI_DEVICE_ERROR;
  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = &Private->Mode;

  if (!Mode->AutoArp) {
    //
    // If AutoArp is set false, check arp cache
    //
    UpdateArpCache (This);
    if (!FindInArpCache (Mode, &ServerIp->v4, &TempMacAddr)) {
      return EFI_DEVICE_ERROR;
    }
  }

  Mode->TftpErrorReceived = FALSE;
  Mode->IcmpErrorReceived = FALSE;

  Mtftp4Config.UseDefaultSetting = FALSE;
  Mtftp4Config.TimeoutValue      = PXEBC_MTFTP_TIMEOUT;
  Mtftp4Config.TryCount          = PXEBC_MTFTP_RETRIES;

  CopyMem (&Mtftp4Config.StationIp, &Private->StationIp, sizeof (EFI_IPv4_ADDRESS));
  CopyMem (&Mtftp4Config.SubnetMask, &Private->SubnetMask, sizeof (EFI_IPv4_ADDRESS));
  CopyMem (&Mtftp4Config.GatewayIp, &Private->GatewayIp, sizeof (EFI_IPv4_ADDRESS));
  CopyMem (&Mtftp4Config.ServerIp, ServerIp, sizeof (EFI_IPv4_ADDRESS));

  switch (Operation) {

  case EFI_PXE_BASE_CODE_TFTP_GET_FILE_SIZE:

    Status = PxeBcTftpGetFileSize (
              Private,
              &Mtftp4Config,
              Filename,
              BlockSize,
              BufferSize
              );

    if (!EFI_ERROR (Status)) {
      Status = EFI_BUFFER_TOO_SMALL;
    }

    break;

  case EFI_PXE_BASE_CODE_TFTP_READ_FILE:

    Status = PxeBcTftpReadFile (
              Private,
              &Mtftp4Config,
              Filename,
              BlockSize,
              BufferPtr,
              BufferSize,
              DontUseBuffer
              );

    break;

  case EFI_PXE_BASE_CODE_TFTP_WRITE_FILE:

    Status = PxeBcTftpWriteFile (
              Private,
              &Mtftp4Config,
              Filename,
              Overwrite,
              BlockSize,
              BufferPtr,
              BufferSize
              );

    break;

  case EFI_PXE_BASE_CODE_TFTP_READ_DIRECTORY:

    Status = PxeBcTftpReadDirectory (
              Private,
              &Mtftp4Config,
              Filename,
              BlockSize,
              BufferPtr,
              BufferSize,
              DontUseBuffer
              );

    break;

  case EFI_PXE_BASE_CODE_MTFTP_GET_FILE_SIZE:
  case EFI_PXE_BASE_CODE_MTFTP_READ_FILE:
  case EFI_PXE_BASE_CODE_MTFTP_READ_DIRECTORY:
    Status = EFI_UNSUPPORTED;
    break;

  default:

    Status = EFI_INVALID_PARAMETER;
    break;
  }

  if (Status == EFI_ICMP_ERROR) {
    Mode->IcmpErrorReceived = TRUE;
  }

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  OpFlags                                     GC_NOTO: add argument
                                                      description
  @param  DestIp                                      GC_NOTO: add argument
                                                      description
  @param  DestPort                                    GC_NOTO: add argument
                                                      description
  @param  GatewayIp                                   GC_NOTO: add argument
                                                      description
  @param  SrcIp                                       GC_NOTO: add argument
                                                      description
  @param  SrcPort                                     GC_NOTO: add argument
                                                      description
  @param  HeaderSize                                  GC_NOTO: add argument
                                                      description
  @param  HeaderPtr                                   GC_NOTO: add argument
                                                      description
  @param  BufferSize                                  GC_NOTO: add argument
                                                      description
  @param  BufferPtr                                   GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_OUT_OF_RESOURCES                        GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcUdpWrite (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN UINT16                           OpFlags,
  IN EFI_IP_ADDRESS                   *DestIp,
  IN EFI_PXE_BASE_CODE_UDP_PORT       *DestPort,
  IN EFI_IP_ADDRESS                   *GatewayIp  OPTIONAL,
  IN EFI_IP_ADDRESS                   *SrcIp      OPTIONAL,
  IN OUT EFI_PXE_BASE_CODE_UDP_PORT   *SrcPort    OPTIONAL,
  IN UINTN                            *HeaderSize OPTIONAL,
  IN VOID                             *HeaderPtr  OPTIONAL,
  IN UINTN                            *BufferSize,
  IN VOID                             *BufferPtr
  )
{
  PXEBC_PRIVATE_DATA        *Private;
  EFI_UDP4_PROTOCOL         *Udp4;
  EFI_UDP4_COMPLETION_TOKEN Token;
  EFI_UDP4_TRANSMIT_DATA    *Udp4TxData;
  UINT32                    FragCount;
  UINT32                    DataLength;
  EFI_UDP4_SESSION_DATA     Udp4Session;
  EFI_STATUS                Status;
  BOOLEAN                   IsDone;
  EFI_PXE_BASE_CODE_MODE    *Mode;
  EFI_MAC_ADDRESS           TempMacAddr;

  IsDone = FALSE;

  if ((This == NULL) || (DestIp == NULL) || (DestPort == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((GatewayIp != NULL) && !Ip4IsUnicast (NTOHL (GatewayIp->Addr[0]), 0)) {
    //
    // Gateway is provided but it's not a unicast IP address.
    //
    return EFI_INVALID_PARAMETER;
  }

  if ((HeaderSize != NULL) && ((*HeaderSize == 0) || (HeaderPtr == NULL))) {
    //
    // The HeaderSize ptr isn't NULL and: 1. the value is zero; or 2. the HeaderPtr
    // is NULL.
    //
    return EFI_INVALID_PARAMETER;
  }

  if ((BufferSize == NULL) || ((*BufferSize != 0) && (BufferPtr == NULL))) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Udp4    = Private->Udp4Write;
  Mode    = &Private->Mode;
  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  if (!Private->AddressIsOk && (SrcIp == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if (!Mode->AutoArp) {
    //
    // If AutoArp is set false, check arp cache
    //
    UpdateArpCache (This);
    if (!FindInArpCache (Mode, &DestIp->v4, &TempMacAddr)) {
      return EFI_DEVICE_ERROR;
    }
  }

  Mode->IcmpErrorReceived = FALSE;

  if ((Private->CurrentUdpSrcPort == 0) ||
    ((SrcPort != NULL) && (*SrcPort != Private->CurrentUdpSrcPort))) {
    //
    // Port is changed, (re)configure the Udp4Write instance
    //
    if (SrcPort != NULL) {
      Private->CurrentUdpSrcPort = *SrcPort;
    }

    Status = PxeBcConfigureUdpWriteInstance (
               Udp4,
               &Private->StationIp.v4,
               &Private->SubnetMask.v4,
               &Private->GatewayIp.v4,
               &Private->CurrentUdpSrcPort
               );
    if (EFI_ERROR (Status)) {
      Private->CurrentUdpSrcPort = 0;
      return EFI_INVALID_PARAMETER;
    }
  }

  ZeroMem (&Token, sizeof (EFI_UDP4_COMPLETION_TOKEN));
  ZeroMem (&Udp4Session, sizeof (EFI_UDP4_SESSION_DATA));

  CopyMem (&Udp4Session.DestinationAddress, DestIp, sizeof (EFI_IPv4_ADDRESS));
  Udp4Session.DestinationPort = *DestPort;
  if (SrcIp != NULL) {
    CopyMem (&Udp4Session.SourceAddress, SrcIp, sizeof (EFI_IPv4_ADDRESS));
  }
  if (SrcPort != NULL) {
    Udp4Session.SourcePort = *SrcPort;
  }

  FragCount = (HeaderSize != NULL) ? 2 : 1;
  Udp4TxData = (EFI_UDP4_TRANSMIT_DATA *) AllocatePool (sizeof (EFI_UDP4_TRANSMIT_DATA) + (FragCount - 1) * sizeof (EFI_UDP4_FRAGMENT_DATA));
  if (Udp4TxData == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  Udp4TxData->FragmentCount = FragCount;
  Udp4TxData->FragmentTable[FragCount - 1].FragmentLength = (UINT32) *BufferSize;
  Udp4TxData->FragmentTable[FragCount - 1].FragmentBuffer = BufferPtr;
  DataLength = (UINT32) *BufferSize;

  if (FragCount == 2) {

    Udp4TxData->FragmentTable[0].FragmentLength = (UINT32) *HeaderSize;
    Udp4TxData->FragmentTable[0].FragmentBuffer = HeaderPtr;
    DataLength += (UINT32) *HeaderSize;
  }

  if (GatewayIp != NULL) {
    Udp4TxData->GatewayAddress  = (EFI_IPv4_ADDRESS *) GatewayIp;
  }
  Udp4TxData->UdpSessionData  = &Udp4Session;
  Udp4TxData->DataLength      = DataLength;
  Token.Packet.TxData         = Udp4TxData;

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  PxeBcCommonNotify,
                  &IsDone,
                  &Token.Event
                  );
  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Status = Udp4->Transmit (Udp4, &Token);
  if (EFI_ERROR (Status)) {
    if (Status == EFI_ICMP_ERROR) {
      Mode->IcmpErrorReceived = TRUE;
    }
    goto ON_EXIT;
  }

  while (!IsDone) {

    Udp4->Poll (Udp4);
  }

  Status = Token.Status;

ON_EXIT:

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

  gBS->FreePool (Udp4TxData);

  return Status;
}

/**
  Validate IP packages by IP filter settings

  @param  PxeBcMode          Pointer to EFI_PXEBC_MODE

  @param  Session            Received UDP session

  @retval TRUE               The UDP package matches IP filters

  @retval FLASE              The UDP package doesn't matches IP filters

**/
STATIC
BOOLEAN
CheckIpByFilter (
  EFI_PXE_BASE_CODE_MODE    *PxeBcMode,
  EFI_UDP4_SESSION_DATA     *Session
  )
{
  UINTN                   Index;
  EFI_IPv4_ADDRESS        Ip4Address;
  EFI_IPv4_ADDRESS        DestIp4Address;

  if (PxeBcMode->IpFilter.Filters & EFI_PXE_BASE_CODE_IP_FILTER_PROMISCUOUS) {
    return TRUE;
  }

  CopyMem (&DestIp4Address, &Session->DestinationAddress, sizeof (DestIp4Address));
  if ((PxeBcMode->IpFilter.Filters & EFI_PXE_BASE_CODE_IP_FILTER_PROMISCUOUS_MULTICAST) &&
      IP4_IS_MULTICAST (EFI_NTOHL (DestIp4Address))
      ) {
    return TRUE;
  }

  if ((PxeBcMode->IpFilter.Filters & EFI_PXE_BASE_CODE_IP_FILTER_BROADCAST) &&
      IP4_IS_LOCAL_BROADCAST (EFI_NTOHL (DestIp4Address))
      ) {
    return TRUE;
  }

  CopyMem (&Ip4Address, &PxeBcMode->StationIp.v4, sizeof (Ip4Address));
  if ((PxeBcMode->IpFilter.Filters & EFI_PXE_BASE_CODE_IP_FILTER_STATION_IP) &&
      EFI_IP4_EQUAL (&Ip4Address, &DestIp4Address)
      ) {
    return TRUE;
  }

  for (Index = 0; Index < PxeBcMode->IpFilter.IpCnt; ++Index) {
    CopyMem (&Ip4Address, &PxeBcMode->IpFilter.IpList[Index].v4, sizeof (Ip4Address));
    if (EFI_IP4_EQUAL (&Ip4Address, &DestIp4Address)) {
      return TRUE;
    }
  }

  return FALSE;
}

/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  OpFlags                                     GC_NOTO: add argument
                                                      description
  @param  DestIp                                      GC_NOTO: add argument
                                                      description
  @param  DestPort                                    GC_NOTO: add argument
                                                      description
  @param  SrcIp                                       GC_NOTO: add argument
                                                      description
  @param  SrcPort                                     GC_NOTO: add argument
                                                      description
  @param  HeaderSize                                  GC_NOTO: add argument
                                                      description
  @param  HeaderPtr                                   GC_NOTO: add argument
                                                      description
  @param  BufferSize                                  GC_NOTO: add argument
                                                      description
  @param  BufferPtr                                   GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_OUT_OF_RESOURCES                        GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcUdpRead (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN UINT16                           OpFlags,
  IN OUT EFI_IP_ADDRESS               *DestIp, OPTIONAL
  IN OUT EFI_PXE_BASE_CODE_UDP_PORT   *DestPort, OPTIONAL
  IN OUT EFI_IP_ADDRESS               *SrcIp, OPTIONAL
  IN OUT EFI_PXE_BASE_CODE_UDP_PORT   *SrcPort, OPTIONAL
  IN UINTN                            *HeaderSize, OPTIONAL
  IN VOID                             *HeaderPtr, OPTIONAL
  IN OUT UINTN                        *BufferSize,
  IN VOID                             *BufferPtr
  )
{
  PXEBC_PRIVATE_DATA        *Private;
  EFI_PXE_BASE_CODE_MODE    *Mode;
  EFI_UDP4_PROTOCOL         *Udp4;
  EFI_UDP4_COMPLETION_TOKEN Token;
  EFI_UDP4_RECEIVE_DATA     *RxData;
  EFI_UDP4_SESSION_DATA     *Session;
  EFI_STATUS                Status;
  BOOLEAN                   IsDone;
  BOOLEAN                   Matched;
  UINTN                     CopyLen;

  if (This == NULL || DestIp == NULL || DestPort == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if ((!(OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_DEST_PORT) && (DestPort == NULL)) ||
      (!(OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_DEST_PORT) && (SrcIp == NULL)) ||
      (!(OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_SRC_PORT) && (SrcPort == NULL))) {
    return EFI_INVALID_PARAMETER;
  }

  if (((HeaderSize != NULL) && (*HeaderSize == 0)) || ((HeaderSize != NULL) && (HeaderPtr == NULL))) {
    return EFI_INVALID_PARAMETER;
  }

  if ((BufferSize == NULL) || ((BufferPtr == NULL) && (*BufferSize != 0))) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;
  Udp4    = Private->Udp4Read;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  Mode->IcmpErrorReceived = FALSE;

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  PxeBcCommonNotify,
                  &IsDone,
                  &Token.Event
                  );
  if (EFI_ERROR (Status)) {
    return EFI_OUT_OF_RESOURCES;
  }

TRY_AGAIN:

  IsDone = FALSE;
  Status = Udp4->Receive (Udp4, &Token);
  if (EFI_ERROR (Status)) {
    if (Status == EFI_ICMP_ERROR) {
      Mode->IcmpErrorReceived = TRUE;
    }
    goto ON_EXIT;
  }

  Udp4->Poll (Udp4);

  if (!IsDone) {
    Status = EFI_TIMEOUT;
  } else {

    //
    // check whether this packet matches the filters
    //
    if (EFI_ERROR (Token.Status)){
      goto ON_EXIT;
    }

    RxData  = Token.Packet.RxData;
    Session = &RxData->UdpSession;

    Matched = FALSE;

    if (OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_USE_FILTER) {
      //
      // Check UDP package by IP filter settings
      //
      if (CheckIpByFilter (Mode, Session)) {
        Matched = TRUE;
      }
    }

    if (Matched) {
      Matched = FALSE;

      //
      // Match the destination ip of the received udp dgram
      //
      if (OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_DEST_IP) {
        Matched = TRUE;

        if (DestIp != NULL) {
          CopyMem (DestIp, &Session->DestinationAddress, sizeof (EFI_IPv4_ADDRESS));
        }
      } else {
        if (DestIp != NULL) {
          if (EFI_IP4_EQUAL (DestIp, &Session->DestinationAddress)) {
            Matched = TRUE;
          }
        } else {
          if (EFI_IP4_EQUAL (&Private->StationIp, &Session->DestinationAddress)) {
            Matched = TRUE;
          }
        }
      }
    }

    if (Matched) {
      //
      // Match the destination port of the received udp dgram
      //
      if (OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_DEST_PORT) {

        if (DestPort != NULL) {
          *DestPort = Session->DestinationPort;
        }
      } else {

        if (*DestPort != Session->DestinationPort) {
          Matched = FALSE;
        }
      }
    }

    if (Matched) {
      //
      // Match the source ip of the received udp dgram
      //
      if (OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_SRC_IP) {

        if (SrcIp != NULL) {
          CopyMem (SrcIp, &Session->SourceAddress, sizeof (EFI_IPv4_ADDRESS));
        }
      } else {

        if (!EFI_IP4_EQUAL (SrcIp, &Session->SourceAddress)) {
          Matched = FALSE;
        }
      }
    }

    if (Matched) {
      //
      // Match the source port of the received udp dgram
      //
      if (OpFlags & EFI_PXE_BASE_CODE_UDP_OPFLAGS_ANY_SRC_PORT) {

        if (SrcPort != NULL) {
          *SrcPort = Session->SourcePort;
        }
      } else {

        if (*SrcPort != Session->SourcePort) {
          Matched = FALSE;
        }
      }
    }

    if (Matched) {

      CopyLen = 0;

      if (HeaderSize != NULL) {
        CopyLen = MIN (*HeaderSize, RxData->DataLength);
        CopyMem (HeaderPtr, RxData->FragmentTable[0].FragmentBuffer, CopyLen);
        *HeaderSize = CopyLen;
      }

      if (RxData->DataLength - CopyLen > *BufferSize) {

        Status = EFI_BUFFER_TOO_SMALL;
      } else {

        *BufferSize = RxData->DataLength - CopyLen;
        CopyMem (BufferPtr, (UINT8 *) RxData->FragmentTable[0].FragmentBuffer + CopyLen, *BufferSize);
      }
    } else {

      Status = EFI_TIMEOUT;
    }

    //
    // Recycle the RxData
    //
    gBS->SignalEvent (RxData->RecycleSignal);

    if (!Matched) {
      goto TRY_AGAIN;
    }
  }

ON_EXIT:

  Udp4->Cancel (Udp4, &Token);

  gBS->CloseEvent (Token.Event);

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  NewFilter                                   GC_NOTO: add argument
                                                      description

  @retval EFI_UNSUPPORTED                             GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcSetIpFilter (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN EFI_PXE_BASE_CODE_IP_FILTER      *NewFilter
  )
{
  EFI_STATUS                Status;
  PXEBC_PRIVATE_DATA        *Private;
  EFI_PXE_BASE_CODE_MODE    *Mode;
  UINTN                     Index;
  BOOLEAN                   PromiscuousNeed;

  if (This == NULL) {
    DEBUG ((EFI_D_ERROR, "BC *This pointer == NULL.\n"));
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode = Private->PxeBc.Mode;

  if (Private == NULL) {
    DEBUG ((EFI_D_ERROR, "PXEBC_PRIVATE_DATA poiner == NULL.\n"));
    return EFI_INVALID_PARAMETER;
  }

  if (NewFilter == NULL) {
    DEBUG ((EFI_D_ERROR, "IP Filter *NewFilter == NULL.\n"));
    return EFI_INVALID_PARAMETER;
  }

  if (!Mode->Started) {
    DEBUG ((EFI_D_ERROR, "BC was not started.\n"));
    return EFI_NOT_STARTED;
  }

  PromiscuousNeed = FALSE;
  for (Index = 0; Index < NewFilter->IpCnt; ++Index) {
    if (IP4_IS_LOCAL_BROADCAST (EFI_IP4 (NewFilter->IpList[Index].v4))) {
      //
      // The IP is a broadcast address.
      //
      DEBUG ((EFI_D_ERROR, "There is broadcast address in NewFilter.\n"));
      return EFI_INVALID_PARAMETER;
    }
    if (Ip4IsUnicast (EFI_IP4 (NewFilter->IpList[Index].v4), 0) &&
        (NewFilter->Filters & EFI_PXE_BASE_CODE_IP_FILTER_STATION_IP)
       ) {
      //
      // If EFI_PXE_BASE_CODE_IP_FILTER_STATION_IP is set and IP4 address is in IpList,
      // promiscuous mode is needed.
      //
      PromiscuousNeed = TRUE;
    }
  }

  //
  // Clear the UDP instance configuration, all joined groups will be left
  // during the operation.
  //
  Private->Udp4Read->Configure (Private->Udp4Read, NULL);
  Private->Udp4CfgData.AcceptPromiscuous  = FALSE;
  Private->Udp4CfgData.AcceptBroadcast    = FALSE;

  if (PromiscuousNeed ||
      NewFilter->Filters & EFI_PXE_BASE_CODE_IP_FILTER_PROMISCUOUS ||
      NewFilter->Filters & EFI_PXE_BASE_CODE_IP_FILTER_PROMISCUOUS_MULTICAST
     ) {
    //
    // Configure the udp4 filter to receive all packages
    //
    Private->Udp4CfgData.AcceptPromiscuous  = TRUE;

    //
    // Configure the UDP instance with the new configuration.
    //
    Status = Private->Udp4Read->Configure (Private->Udp4Read, &Private->Udp4CfgData);
    if (EFI_ERROR (Status)) {
      return Status;
    }

  } else {

    if (NewFilter->Filters & EFI_PXE_BASE_CODE_IP_FILTER_BROADCAST) {
      //
      // Configure the udp4 filter to receive all broadcast packages
      //
      Private->Udp4CfgData.AcceptBroadcast    = TRUE;
    }

    //
    // Configure the UDP instance with the new configuration.
    //
    Status = Private->Udp4Read->Configure (Private->Udp4Read, &Private->Udp4CfgData);
    if (EFI_ERROR (Status)) {
      return Status;
    }

    if (NewFilter->Filters & EFI_PXE_BASE_CODE_IP_FILTER_STATION_IP) {

      for (Index = 0; Index < NewFilter->IpCnt; ++Index) {
        if (IP4_IS_MULTICAST (EFI_NTOHL (NewFilter->IpList[Index].v4))) {
          //
          // Join the mutilcast group
          //
          Status = Private->Udp4Read->Groups (Private->Udp4Read, TRUE, &NewFilter->IpList[Index].v4);
          if (EFI_ERROR (Status)) {
            return Status;
          }
        }
      }
    }
  }


  //
  // Save the new filter.
  //
  CopyMem (&Mode->IpFilter, NewFilter, sizeof (Mode->IpFilter));

  return EFI_SUCCESS;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  IpAddr                                      GC_NOTO: add argument
                                                      description
  @param  MacAddr                                     GC_NOTO: add argument
                                                      description

  @retval EFI_UNSUPPORTED                             GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcArp (
  IN EFI_PXE_BASE_CODE_PROTOCOL       * This,
  IN EFI_IP_ADDRESS                   * IpAddr,
  IN EFI_MAC_ADDRESS                  * MacAddr OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_STATUS              Status;
  EFI_MAC_ADDRESS         TempMacAddr;

  if (This == NULL || IpAddr == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  if (!Private->AddressIsOk || Mode->UsingIpv6) {
    //
    // We can't resolve the IP address if we don't have a local address now.
    // Don't have ARP for IPv6.
    //
    return EFI_INVALID_PARAMETER;
  }

  Mode->IcmpErrorReceived = FALSE;

  if (!Mode->AutoArp) {
    //
    // If AutoArp is set false, check arp cache
    //
    UpdateArpCache (This);
    if (!FindInArpCache (Mode, &IpAddr->v4, &TempMacAddr)) {
      return EFI_DEVICE_ERROR;
    }
  } else {
    Status = Private->Arp->Request (Private->Arp, &IpAddr->v4, NULL, &TempMacAddr);
    if (EFI_ERROR (Status)) {
      if (Status == EFI_ICMP_ERROR) {
        Mode->IcmpErrorReceived = TRUE;
      }
      return Status;
    }
  }

  if (MacAddr != NULL) {
    CopyMem (MacAddr, &TempMacAddr, sizeof (EFI_MAC_ADDRESS));
  }

  return EFI_SUCCESS;
}



/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  NewAutoArp                                  GC_NOTO: add argument
                                                      description
  @param  NewSendGUID                                 GC_NOTO: add argument
                                                      description
  @param  NewTTL                                      GC_NOTO: add argument
                                                      description
  @param  NewToS                                      GC_NOTO: add argument
                                                      description
  @param  NewMakeCallback                             GC_NOTO: add argument
                                                      description

  @return GC_NOTO: add return values

**/
EFI_STATUS
EFIAPI
EfiPxeBcSetParameters (
  IN EFI_PXE_BASE_CODE_PROTOCOL       *This,
  IN BOOLEAN                          *NewAutoArp, OPTIONAL
  IN BOOLEAN                          *NewSendGUID, OPTIONAL
  IN UINT8                            *NewTTL, OPTIONAL
  IN UINT8                            *NewToS, OPTIONAL
  IN BOOLEAN                          *NewMakeCallback  // OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_STATUS              Status;

  Status = EFI_SUCCESS;

  if (This == NULL) {
    Status = EFI_INVALID_PARAMETER;
    goto ON_EXIT;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (NewSendGUID != NULL && *NewSendGUID == TRUE) {
    //
    // FixMe, cann't locate SendGuid
    //
  }

  if (NewMakeCallback != NULL && *NewMakeCallback == TRUE) {

    Status = gBS->HandleProtocol (
                    Private->Controller,
                    &gEfiPxeBaseCodeCallbackProtocolGuid,
                    (VOID **) &Private->PxeBcCallback
                    );
    if (EFI_ERROR (Status) || (Private->PxeBcCallback->Callback == NULL)) {

      Status = EFI_INVALID_PARAMETER;
      goto ON_EXIT;
    }
  }

  if (!Mode->Started) {
    Status = EFI_NOT_STARTED;
    goto ON_EXIT;
  }

  if (NewMakeCallback != NULL) {

    if (*NewMakeCallback) {
      //
      // Update the Callback protocol.
      //
      Status = gBS->HandleProtocol (
                      Private->Controller,
                      &gEfiPxeBaseCodeCallbackProtocolGuid,
                      (VOID **) &Private->PxeBcCallback
                      );

      if (EFI_ERROR (Status) || (Private->PxeBcCallback->Callback == NULL)) {
        Status = EFI_INVALID_PARAMETER;
        goto ON_EXIT;
      }
    } else {
      Private->PxeBcCallback = NULL;
    }

    Mode->MakeCallbacks = *NewMakeCallback;
  }

  if (NewAutoArp != NULL) {
    Mode->AutoArp = *NewAutoArp;
  }

  if (NewSendGUID != NULL) {
    Mode->SendGUID = *NewSendGUID;
  }

  if (NewTTL != NULL) {
    Mode->TTL = *NewTTL;
  }

  if (NewToS != NULL) {
    Mode->ToS = *NewToS;
  }

ON_EXIT:
  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  NewStationIp                                GC_NOTO: add argument
                                                      description
  @param  NewSubnetMask                               GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_SUCCESS                                 GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcSetStationIP (
  IN EFI_PXE_BASE_CODE_PROTOCOL       * This,
  IN EFI_IP_ADDRESS                   * NewStationIp, OPTIONAL
  IN EFI_IP_ADDRESS                   * NewSubnetMask OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;
  EFI_ARP_CONFIG_DATA     ArpConfigData;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (NewStationIp != NULL && !Ip4IsUnicast (NTOHL (NewStationIp->Addr[0]), 0)) {
    return EFI_INVALID_PARAMETER;
  }

  if (NewSubnetMask != NULL && !IP4_IS_VALID_NETMASK (NTOHL (NewSubnetMask->Addr[0]))) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  if (NewStationIp != NULL) {
    Mode->StationIp    = *NewStationIp;
    Private->StationIp = *NewStationIp;
  }

  if (NewSubnetMask != NULL) {
    Mode->SubnetMask    = *NewSubnetMask;
    Private->SubnetMask = *NewSubnetMask;
  }

  Private->AddressIsOk = TRUE;

  if (!Mode->UsingIpv6) {
    //
    // If in IPv4 mode, configure the corresponding ARP with this new
    // station IP address.
    //
    ZeroMem (&ArpConfigData, sizeof (EFI_ARP_CONFIG_DATA));

    ArpConfigData.SwAddressType   = 0x0800;
    ArpConfigData.SwAddressLength = sizeof (EFI_IPv4_ADDRESS);
    ArpConfigData.StationAddress  = &Private->StationIp.v4;

    Private->Arp->Configure (Private->Arp, NULL);
    Private->Arp->Configure (Private->Arp, &ArpConfigData);

    //
    // Update the route table.
    //
    Mode->RouteTableEntries                = 1;
    Mode->RouteTable[0].IpAddr.Addr[0]     = Private->StationIp.Addr[0] & Private->SubnetMask.Addr[0];
    Mode->RouteTable[0].SubnetMask.Addr[0] = Private->SubnetMask.Addr[0];
    Mode->RouteTable[0].GwAddr.Addr[0]     = 0;
  }

  return EFI_SUCCESS;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  NewDhcpDiscoverValid                        GC_NOTO: add argument
                                                      description
  @param  NewDhcpAckReceived                          GC_NOTO: add argument
                                                      description
  @param  NewProxyOfferReceived                       GC_NOTO: add argument
                                                      description
  @param  NewPxeDiscoverValid                         GC_NOTO: add argument
                                                      description
  @param  NewPxeReplyReceived                         GC_NOTO: add argument
                                                      description
  @param  NewPxeBisReplyReceived                      GC_NOTO: add argument
                                                      description
  @param  NewDhcpDiscover                             GC_NOTO: add argument
                                                      description
  @param  NewDhcpAck                                  GC_NOTO: add argument
                                                      description
  @param  NewProxyOffer                               GC_NOTO: add argument
                                                      description
  @param  NewPxeDiscover                              GC_NOTO: add argument
                                                      description
  @param  NewPxeReply                                 GC_NOTO: add argument
                                                      description
  @param  NewPxeBisReply                              GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_NOT_STARTED                             GC_NOTO: Add description for
                                                      return value
  @retval EFI_SUCCESS                                 GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeBcSetPackets (
  IN EFI_PXE_BASE_CODE_PROTOCOL       * This,
  IN BOOLEAN                          * NewDhcpDiscoverValid, OPTIONAL
  IN BOOLEAN                          * NewDhcpAckReceived, OPTIONAL
  IN BOOLEAN                          * NewProxyOfferReceived, OPTIONAL
  IN BOOLEAN                          * NewPxeDiscoverValid, OPTIONAL
  IN BOOLEAN                          * NewPxeReplyReceived, OPTIONAL
  IN BOOLEAN                          * NewPxeBisReplyReceived, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewDhcpDiscover, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewDhcpAck, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewProxyOffer, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewPxeDiscover, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewPxeReply, OPTIONAL
  IN EFI_PXE_BASE_CODE_PACKET         * NewPxeBisReply OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA      *Private;
  EFI_PXE_BASE_CODE_MODE  *Mode;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Private = PXEBC_PRIVATE_DATA_FROM_PXEBC (This);
  Mode    = Private->PxeBc.Mode;

  if (!Mode->Started) {
    return EFI_NOT_STARTED;
  }

  Private->FileSize = 0;

  if (NewDhcpDiscoverValid != NULL) {
    Mode->DhcpDiscoverValid = *NewDhcpDiscoverValid;
  }

  if (NewDhcpAckReceived != NULL) {
    Mode->DhcpAckReceived = *NewDhcpAckReceived;
  }

  if (NewProxyOfferReceived != NULL) {
    Mode->ProxyOfferReceived = *NewProxyOfferReceived;
  }

  if (NewPxeDiscoverValid != NULL) {
    Mode->PxeDiscoverValid = *NewPxeDiscoverValid;
  }

  if (NewPxeReplyReceived != NULL) {
    Mode->PxeReplyReceived = *NewPxeReplyReceived;
  }

  if (NewPxeBisReplyReceived != NULL) {
    Mode->PxeBisReplyReceived = *NewPxeBisReplyReceived;
  }

  if (NewDhcpDiscover != NULL) {
    CopyMem (&Mode->DhcpDiscover, NewDhcpDiscover, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  if (NewDhcpAck != NULL) {
    CopyMem (&Mode->DhcpAck, NewDhcpAck, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  if (NewProxyOffer != NULL) {
    CopyMem (&Mode->ProxyOffer, NewProxyOffer, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  if (NewPxeDiscover != NULL) {
    CopyMem (&Mode->PxeDiscover, NewPxeDiscover, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  if (NewPxeReply != NULL) {
    CopyMem (&Mode->PxeReply, NewPxeReply, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  if (NewPxeBisReply != NULL) {
    CopyMem (&Mode->PxeBisReply, NewPxeBisReply, sizeof (EFI_PXE_BASE_CODE_PACKET));
  }

  return EFI_SUCCESS;
}

EFI_PXE_BASE_CODE_PROTOCOL  mPxeBcProtocolTemplate = {
  EFI_PXE_BASE_CODE_PROTOCOL_REVISION,
  EfiPxeBcStart,
  EfiPxeBcStop,
  EfiPxeBcDhcp,
  EfiPxeBcDiscover,
  EfiPxeBcMtftp,
  EfiPxeBcUdpWrite,
  EfiPxeBcUdpRead,
  EfiPxeBcSetIpFilter,
  EfiPxeBcArp,
  EfiPxeBcSetParameters,
  EfiPxeBcSetStationIP,
  EfiPxeBcSetPackets,
  NULL
};


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  Function                                    GC_NOTO: add argument
                                                      description
  @param  Received                                    GC_NOTO: add argument
                                                      description
  @param  PacketLength                                GC_NOTO: add argument
                                                      description
  @param  PacketPtr                                   GC_NOTO: add argument
                                                      description

  @retval EFI_PXE_BASE_CODE_CALLBACK_STATUS_ABORT     GC_NOTO: Add description for
                                                      return value
  @retval EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE  GC_NOTO: Add description for
                                                      return value
  @retval EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE  GC_NOTO: Add description for
                                                      return value
  @retval EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE  GC_NOTO: Add description for
                                                      return value
  @retval EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE  GC_NOTO: Add description for
                                                      return value

**/
EFI_PXE_BASE_CODE_CALLBACK_STATUS
EFIAPI
EfiPxeLoadFileCallback (
  IN EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL  * This,
  IN EFI_PXE_BASE_CODE_FUNCTION           Function,
  IN BOOLEAN                              Received,
  IN UINT32                               PacketLength,
  IN EFI_PXE_BASE_CODE_PACKET             * PacketPtr OPTIONAL
  )
{
  EFI_INPUT_KEY Key;
  EFI_STATUS    Status;

  //
  // Catch Ctrl-C or ESC to abort.
  //
  Status = gST->ConIn->ReadKeyStroke (gST->ConIn, &Key);

  if (!EFI_ERROR (Status)) {

    if (Key.ScanCode == SCAN_ESC || Key.UnicodeChar == (0x1F & 'c')) {

      return EFI_PXE_BASE_CODE_CALLBACK_STATUS_ABORT;
    }
  }
  //
  // No print if receive packet
  //
  if (Received) {
    return EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE;
  }
  //
  // Print only for three functions
  //
  switch (Function) {

  case EFI_PXE_BASE_CODE_FUNCTION_MTFTP:
    //
    // Print only for open MTFTP packets, not every MTFTP packets
    //
    if (PacketLength != 0 && PacketPtr != NULL) {
      if (PacketPtr->Raw[0x1C] != 0x00 || PacketPtr->Raw[0x1D] != 0x01) {
        return EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE;
      }
    }
    break;

  case EFI_PXE_BASE_CODE_FUNCTION_DHCP:
  case EFI_PXE_BASE_CODE_FUNCTION_DISCOVER:
    break;

  default:
    return EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE;
  }

  if (PacketLength != 0 && PacketPtr != NULL) {
    //
    // Print '.' when transmit a packet
    //
    AsciiPrint (".");

  }

  return EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE;
}

EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL mPxeBcCallBackTemplate = {
  EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL_REVISION,
  EfiPxeLoadFileCallback
};


/**
  GC_NOTO: Add function description

  @param  Private                                     GC_NOTO: add argument
                                                      description
  @param  BufferSize                                  GC_NOTO: add argument
                                                      description
  @param  Buffer                                      GC_NOTO: add argument
                                                      description

  @return GC_NOTO: add return values

**/
EFI_STATUS
DiscoverBootFile (
  IN     PXEBC_PRIVATE_DATA  *Private,
  IN OUT UINT64              *BufferSize,
  IN     VOID                *Buffer
  )
{
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;
  EFI_PXE_BASE_CODE_MODE      *Mode;
  EFI_STATUS                  Status;
  UINT16                      Type;
  UINT16                      Layer;
  BOOLEAN                     UseBis;
  UINTN                       BlockSize;
  PXEBC_CACHED_DHCP4_PACKET   *Packet;
  UINT16                      Value;

  PxeBc = &Private->PxeBc;
  Mode  = PxeBc->Mode;
  Type  = EFI_PXE_BASE_CODE_BOOT_TYPE_BOOTSTRAP;
  Layer = EFI_PXE_BASE_CODE_BOOT_LAYER_INITIAL;

  //
  // do DHCP.
  //
  Status = PxeBc->Dhcp (PxeBc, TRUE);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Select a boot server
  //
  Status = PxeBcSelectBootPrompt (Private);

  if (Status == EFI_SUCCESS) {
    Status = PxeBcSelectBootMenu (Private, &Type, TRUE);
  } else if (Status == EFI_TIMEOUT) {
    Status = PxeBcSelectBootMenu (Private, &Type, FALSE);
  }

  if (!EFI_ERROR (Status)) {

    if (Type == EFI_PXE_BASE_CODE_BOOT_TYPE_BOOTSTRAP) {
      //
      // Local boot(PXE bootstrap server) need abort
      //
      return EFI_ABORTED;
    }

    UseBis  = (BOOLEAN) (Mode->BisSupported && Mode->BisDetected);
    Status  = PxeBc->Discover (PxeBc, Type, &Layer, UseBis, NULL);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }

  *BufferSize = 0;
  BlockSize   = 0x8000;

  //
  // Get bootfile name and (m)tftp server ip addresss
  //
  if (Mode->PxeReplyReceived) {
    Packet = &Private->PxeReply;
  } else if (Mode->ProxyOfferReceived) {
    Packet = &Private->ProxyOffer;
  } else {
    Packet = &Private->Dhcp4Ack;
  }

  CopyMem (&Private->ServerIp, &Packet->Packet.Offer.Dhcp4.Header.ServerAddr, sizeof (EFI_IPv4_ADDRESS));
  if (Private->ServerIp.Addr[0] == 0) {
    //
    // next server ip address is zero, use option 54 instead
    //
    CopyMem (
      &Private->ServerIp,
      Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_SERVER_ID]->Data,
      sizeof (EFI_IPv4_ADDRESS)
      );
  }

  ASSERT (Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_BOOTFILE] != NULL);

  //
  // bootlfile name
  //
  Private->BootFileName = (CHAR8 *) (Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_BOOTFILE]->Data);

  if (Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_BOOTFILE_LEN] != NULL) {
    //
    // Already have the bootfile length option, compute the file size
    //
    CopyMem (&Value, Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_BOOTFILE_LEN]->Data, sizeof (Value));
    Value       = NTOHS (Value);
    *BufferSize = 512 * Value;
    Status      = EFI_BUFFER_TOO_SMALL;
  } else {
    //
    // Get the bootfile size from tftp
    //
    Status = PxeBc->Mtftp (
                      PxeBc,
                      EFI_PXE_BASE_CODE_TFTP_GET_FILE_SIZE,
                      Buffer,
                      FALSE,
                      BufferSize,
                      &BlockSize,
                      &Private->ServerIp,
                      (UINT8 *) Private->BootFileName,
                      NULL,
                      FALSE
                      );
  }

  Private->FileSize = (UINTN) *BufferSize;

  return Status;
}


/**
  GC_NOTO: Add function description

  @param  This                                        GC_NOTO: add argument
                                                      description
  @param  FilePath                                    GC_NOTO: add argument
                                                      description
  @param  BootPolicy                                  GC_NOTO: add argument
                                                      description
  @param  BufferSize                                  GC_NOTO: add argument
                                                      description
  @param  Buffer                                      GC_NOTO: add argument
                                                      description

  @retval EFI_INVALID_PARAMETER                       GC_NOTO: Add description for
                                                      return value
  @retval EFI_UNSUPPORTED                             GC_NOTO: Add description for
                                                      return value

**/
EFI_STATUS
EFIAPI
EfiPxeLoadFile (
  IN EFI_LOAD_FILE_PROTOCOL           * This,
  IN EFI_DEVICE_PATH_PROTOCOL         * FilePath,
  IN BOOLEAN                          BootPolicy,
  IN OUT UINTN                        *BufferSize,
  IN VOID                             *Buffer OPTIONAL
  )
{
  PXEBC_PRIVATE_DATA          *Private;
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;
  BOOLEAN                     NewMakeCallback;
  UINTN                       BlockSize;
  EFI_STATUS                  Status;
  UINT64                      TmpBufSize;

  Private         = PXEBC_PRIVATE_DATA_FROM_LOADFILE (This);
  PxeBc           = &Private->PxeBc;
  NewMakeCallback = FALSE;
  BlockSize       = 0x8000;
  Status          = EFI_DEVICE_ERROR;

  if (This == NULL || BufferSize == NULL) {

    return EFI_INVALID_PARAMETER;
  }

  //
  // Only support BootPolicy
  //
  if (!BootPolicy) {
    return EFI_UNSUPPORTED;
  }

  Status = PxeBc->Start (PxeBc, FALSE);
  if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
    return Status;
  }

  Status = gBS->HandleProtocol (
                  Private->Controller,
                  &gEfiPxeBaseCodeCallbackProtocolGuid,
                  (VOID **) &Private->PxeBcCallback
                  );
  if (Status == EFI_UNSUPPORTED) {

    CopyMem (&Private->LoadFileCallback, &mPxeBcCallBackTemplate, sizeof (Private->LoadFileCallback));

    Status = gBS->InstallProtocolInterface (
                    &Private->Controller,
                    &gEfiPxeBaseCodeCallbackProtocolGuid,
                    EFI_NATIVE_INTERFACE,
                    &Private->LoadFileCallback
                    );

    NewMakeCallback = (BOOLEAN) (Status == EFI_SUCCESS);

    Status          = PxeBc->SetParameters (PxeBc, NULL, NULL, NULL, NULL, &NewMakeCallback);
    if (EFI_ERROR (Status)) {
      PxeBc->Stop (PxeBc);
      return Status;
    }
  }

  if (Private->FileSize == 0) {
    TmpBufSize  = 0;
    Status      = DiscoverBootFile (Private, &TmpBufSize, Buffer);

    if (sizeof (UINTN) < sizeof (UINT64) && (TmpBufSize > 0xFFFFFFFF)) {
      Status = EFI_DEVICE_ERROR;
    } else {
      *BufferSize = (UINTN) TmpBufSize;
    }
  } else if (Buffer == NULL) {
    *BufferSize = Private->FileSize;
    Status      = EFI_BUFFER_TOO_SMALL;
  } else {
    //
    // Download the file.
    //
    TmpBufSize = (UINT64) (*BufferSize);
    Status = PxeBc->Mtftp (
                      PxeBc,
                      EFI_PXE_BASE_CODE_TFTP_READ_FILE,
                      Buffer,
                      FALSE,
                      &TmpBufSize,
                      &BlockSize,
                      &Private->ServerIp,
                      (UINT8 *) Private->BootFileName,
                      NULL,
                      FALSE
                      );
  }
  //
  // If we added a callback protocol, now is the time to remove it.
  //
  if (NewMakeCallback) {

    NewMakeCallback = FALSE;

    PxeBc->SetParameters (PxeBc, NULL, NULL, NULL, NULL, &NewMakeCallback);

    gBS->UninstallProtocolInterface (
          Private->Controller,
          &gEfiPxeBaseCodeCallbackProtocolGuid,
          &Private->LoadFileCallback
          );
  }

  //
  // Check download status
  //
  if (Status == EFI_SUCCESS) {
    return EFI_SUCCESS;

  } else if (Status == EFI_BUFFER_TOO_SMALL) {
    if (Buffer != NULL) {
      AsciiPrint ("PXE-E05: Download buffer is smaller than requested file.\n");
    } else {
      return Status;
    }

  } else if (Status == EFI_DEVICE_ERROR) {
    AsciiPrint ("PXE-E07: Network device error.\n");

  } else if (Status == EFI_OUT_OF_RESOURCES) {
    AsciiPrint ("PXE-E09: Could not allocate I/O buffers.\n");

  } else if (Status == EFI_NO_MEDIA) {
    AsciiPrint ("PXE-E12: Could not detect network connection.\n");

  } else if (Status == EFI_NO_RESPONSE) {
    AsciiPrint ("PXE-E16: No offer received.\n");

  } else if (Status == EFI_TIMEOUT) {
    AsciiPrint ("PXE-E18: Server response timeout.\n");

  } else if (Status == EFI_ABORTED) {
    AsciiPrint ("PXE-E21: Remote boot cancelled.\n");

  } else if (Status == EFI_ICMP_ERROR) {
    AsciiPrint ("PXE-E22: Client received ICMP error from server.\n");

  } else if (Status == EFI_TFTP_ERROR) {
    AsciiPrint ("PXE-E23: Client received TFTP error from server.\n");

  } else {
    AsciiPrint ("PXE-E99: Unexpected network error.\n");
  }

  PxeBc->Stop (PxeBc);

  return Status;
}

EFI_LOAD_FILE_PROTOCOL  mLoadFileProtocolTemplate = { EfiPxeLoadFile };