NetworkPkg/HttpBootDxe/HttpBootSupport.c - third_party/edk2 - Git at Google

 /** @file
   Support functions implementation for UEFI HTTP boot driver.

 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
 (C) Copyright 2016 - 2020 Hewlett Packard Enterprise Development LP<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

 #include "HttpBootDxe.h"


 /**
   Get the Nic handle using any child handle in the IPv4 stack.

   @param[in]  ControllerHandle    Pointer to child handle over IPv4.

   @return NicHandle               The pointer to the Nic handle.
   @return NULL                    Can't find the Nic handle.

 **/
 EFI_HANDLE
 HttpBootGetNicByIp4Children (
   IN EFI_HANDLE                 ControllerHandle
   )
 {
   EFI_HANDLE                    NicHandle;

   NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiHttpProtocolGuid);
   if (NicHandle == NULL) {
     NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiDhcp4ProtocolGuid);
     if (NicHandle == NULL) {
       return NULL;
     }
   }

   return NicHandle;
 }

 /**
   Get the Nic handle using any child handle in the IPv6 stack.

   @param[in]  ControllerHandle    Pointer to child handle over IPv6.

   @return NicHandle               The pointer to the Nic handle.
   @return NULL                    Can't find the Nic handle.

 **/
 EFI_HANDLE
 HttpBootGetNicByIp6Children (
   IN EFI_HANDLE                 ControllerHandle
   )
 {
   EFI_HANDLE                    NicHandle;
   NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiHttpProtocolGuid);
   if (NicHandle == NULL) {
     NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiDhcp6ProtocolGuid);
     if (NicHandle == NULL) {
       return NULL;
     }
   }

   return NicHandle;
 }

 /**
   This function is to convert UINTN to ASCII string with the required formatting.

   @param[in]  Number         Numeric value to be converted.
   @param[in]  Buffer         The pointer to the buffer for ASCII string.
   @param[in]  Length         The length of the required format.

 **/
 VOID
 HttpBootUintnToAscDecWithFormat (
   IN UINTN                       Number,
   IN UINT8                       *Buffer,
   IN INTN                        Length
   )
 {
   UINTN                          Remainder;

   for (; Length > 0; Length--) {
     Remainder      = Number % 10;
     Number        /= 10;
     Buffer[Length - 1] = (UINT8) ('0' + Remainder);
   }
 }

 /**
   This function is to display the IPv4 address.

   @param[in]  Ip        The pointer to the IPv4 address.

 **/
 VOID
 HttpBootShowIp4Addr (
   IN EFI_IPv4_ADDRESS   *Ip
   )
 {
   UINTN                 Index;

   for (Index = 0; Index < 4; Index++) {
     AsciiPrint ("%d", Ip->Addr[Index]);
     if (Index < 3) {
       AsciiPrint (".");
     }
   }
 }

 /**
   This function is to display the IPv6 address.

   @param[in]  Ip        The pointer to the IPv6 address.

 **/
 VOID
 HttpBootShowIp6Addr (
   IN EFI_IPv6_ADDRESS   *Ip
   )
 {
   UINTN                 Index;

   for (Index = 0; Index < 16; Index++) {

     if (Ip->Addr[Index] != 0) {
       AsciiPrint ("%x", Ip->Addr[Index]);
     }
     Index++;
     if (Index > 15) {
       return;
     }
     if (((Ip->Addr[Index] & 0xf0) == 0) && (Ip->Addr[Index - 1] != 0)) {
       AsciiPrint ("0");
     }
     AsciiPrint ("%x", Ip->Addr[Index]);
     if (Index < 15) {
       AsciiPrint (":");
     }
   }
 }

 /**
   This function is to display the HTTP error status.

   @param[in]      StatusCode      The status code value in HTTP message.

 **/
 VOID
 HttpBootPrintErrorMessage (
   EFI_HTTP_STATUS_CODE            StatusCode
   )
 {
   AsciiPrint ("\n");

   switch (StatusCode) {
   case HTTP_STATUS_300_MULTIPLE_CHOICES:
     AsciiPrint ("\n  Redirection: 300 Multiple Choices");
     break;

   case HTTP_STATUS_301_MOVED_PERMANENTLY:
     AsciiPrint ("\n  Redirection: 301 Moved Permanently");
     break;

   case HTTP_STATUS_302_FOUND:
     AsciiPrint ("\n  Redirection: 302 Found");
     break;

   case HTTP_STATUS_303_SEE_OTHER:
     AsciiPrint ("\n  Redirection: 303 See Other");
     break;

   case HTTP_STATUS_304_NOT_MODIFIED:
     AsciiPrint ("\n  Redirection: 304 Not Modified");
     break;

   case HTTP_STATUS_305_USE_PROXY:
     AsciiPrint ("\n  Redirection: 305 Use Proxy");
     break;

   case HTTP_STATUS_307_TEMPORARY_REDIRECT:
     AsciiPrint ("\n  Redirection: 307 Temporary Redirect");
     break;

   case HTTP_STATUS_308_PERMANENT_REDIRECT:
     AsciiPrint ("\n  Redirection: 308 Permanent Redirect");
     break;

   case HTTP_STATUS_400_BAD_REQUEST:
     AsciiPrint ("\n  Client Error: 400 Bad Request");
     break;

   case HTTP_STATUS_401_UNAUTHORIZED:
     AsciiPrint ("\n  Client Error: 401 Unauthorized");
     break;

   case HTTP_STATUS_402_PAYMENT_REQUIRED:
     AsciiPrint ("\n  Client Error: 402 Payment Required");
     break;

   case HTTP_STATUS_403_FORBIDDEN:
     AsciiPrint ("\n  Client Error: 403 Forbidden");
     break;

   case HTTP_STATUS_404_NOT_FOUND:
     AsciiPrint ("\n  Client Error: 404 Not Found");
     break;

   case HTTP_STATUS_405_METHOD_NOT_ALLOWED:
     AsciiPrint ("\n  Client Error: 405 Method Not Allowed");
     break;

   case HTTP_STATUS_406_NOT_ACCEPTABLE:
     AsciiPrint ("\n  Client Error: 406 Not Acceptable");
     break;

   case HTTP_STATUS_407_PROXY_AUTHENTICATION_REQUIRED:
     AsciiPrint ("\n  Client Error: 407 Proxy Authentication Required");
     break;

   case HTTP_STATUS_408_REQUEST_TIME_OUT:
     AsciiPrint ("\n  Client Error: 408 Request Timeout");
     break;

   case HTTP_STATUS_409_CONFLICT:
     AsciiPrint ("\n  Client Error: 409 Conflict");
     break;

   case HTTP_STATUS_410_GONE:
     AsciiPrint ("\n  Client Error: 410 Gone");
     break;

   case HTTP_STATUS_411_LENGTH_REQUIRED:
     AsciiPrint ("\n  Client Error: 411 Length Required");
     break;

   case HTTP_STATUS_412_PRECONDITION_FAILED:
     AsciiPrint ("\n  Client Error: 412 Precondition Failed");
     break;

   case HTTP_STATUS_413_REQUEST_ENTITY_TOO_LARGE:
     AsciiPrint ("\n  Client Error: 413 Request Entity Too Large");
     break;

   case HTTP_STATUS_414_REQUEST_URI_TOO_LARGE:
     AsciiPrint ("\n  Client Error: 414 Request URI Too Long");
     break;

   case HTTP_STATUS_415_UNSUPPORTED_MEDIA_TYPE:
     AsciiPrint ("\n  Client Error: 415 Unsupported Media Type");
     break;

   case HTTP_STATUS_416_REQUESTED_RANGE_NOT_SATISFIED:
     AsciiPrint ("\n  Client Error: 416 Requested Range Not Satisfiable");
     break;

   case HTTP_STATUS_417_EXPECTATION_FAILED:
     AsciiPrint ("\n  Client Error: 417 Expectation Failed");
     break;

   case HTTP_STATUS_500_INTERNAL_SERVER_ERROR:
     AsciiPrint ("\n  Server Error: 500 Internal Server Error");
     break;

   case HTTP_STATUS_501_NOT_IMPLEMENTED:
     AsciiPrint ("\n  Server Error: 501 Not Implemented");
     break;

   case HTTP_STATUS_502_BAD_GATEWAY:
     AsciiPrint ("\n  Server Error: 502 Bad Gateway");
     break;

   case HTTP_STATUS_503_SERVICE_UNAVAILABLE:
     AsciiPrint ("\n  Server Error: 503 Service Unavailable");
     break;

   case HTTP_STATUS_504_GATEWAY_TIME_OUT:
     AsciiPrint ("\n  Server Error: 504 Gateway Timeout");
     break;

   case HTTP_STATUS_505_HTTP_VERSION_NOT_SUPPORTED:
     AsciiPrint ("\n  Server Error: 505 HTTP Version Not Supported");
     break;

   default: ;

   }
 }

 /**
   Notify the callback function when an event is triggered.

   @param[in]  Event           The triggered event.
   @param[in]  Context         The opaque parameter to the function.

 **/
 VOID
 EFIAPI
 HttpBootCommonNotify (
   IN EFI_EVENT           Event,
   IN VOID                *Context
   )
 {
   *((BOOLEAN *) Context) = TRUE;
 }

 /**
   Retrieve the host address using the EFI_DNS6_PROTOCOL.

   @param[in]  Private             The pointer to the driver's private data.
   @param[in]  HostName            Pointer to buffer containing hostname.
   @param[out] IpAddress           On output, pointer to buffer containing IPv6 address.

   @retval EFI_SUCCESS             Operation succeeded.
   @retval EFI_DEVICE_ERROR        An unexpected network error occurred.
   @retval Others                  Other errors as indicated.
 **/
 EFI_STATUS
 HttpBootDns (
   IN     HTTP_BOOT_PRIVATE_DATA   *Private,
   IN     CHAR16                   *HostName,
      OUT EFI_IPv6_ADDRESS         *IpAddress
   )
 {
   EFI_STATUS                      Status;
   EFI_DNS6_PROTOCOL               *Dns6;
   EFI_DNS6_CONFIG_DATA            Dns6ConfigData;
   EFI_DNS6_COMPLETION_TOKEN       Token;
   EFI_HANDLE                      Dns6Handle;
   EFI_IP6_CONFIG_PROTOCOL         *Ip6Config;
   EFI_IPv6_ADDRESS                *DnsServerList;
   UINTN                           DnsServerListCount;
   UINTN                           DataSize;
   BOOLEAN                         IsDone;

   DnsServerList       = NULL;
   DnsServerListCount  = 0;
   Dns6                = NULL;
   Dns6Handle          = NULL;
   ZeroMem (&Token, sizeof (EFI_DNS6_COMPLETION_TOKEN));

   //
   // Get DNS server list from EFI IPv6 Configuration protocol.
   //
   Status = gBS->HandleProtocol (Private->Controller, &gEfiIp6ConfigProtocolGuid, (VOID **) &Ip6Config);
   if (!EFI_ERROR (Status)) {
     //
     // Get the required size.
     //
     DataSize = 0;
     Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, NULL);
     if (Status == EFI_BUFFER_TOO_SMALL) {
       DnsServerList = AllocatePool (DataSize);
       if (DnsServerList == NULL) {
         return EFI_OUT_OF_RESOURCES;
       }

       Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, DnsServerList);
       if (EFI_ERROR (Status)) {
         FreePool (DnsServerList);
         DnsServerList = NULL;
       } else {
         DnsServerListCount = DataSize / sizeof (EFI_IPv6_ADDRESS);
       }
     }
   }
   //
   // Create a DNSv6 child instance and get the protocol.
   //
   Status = NetLibCreateServiceChild (
              Private->Controller,
              Private->Ip6Nic->ImageHandle,
              &gEfiDns6ServiceBindingProtocolGuid,
              &Dns6Handle
              );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   Status = gBS->OpenProtocol (
                   Dns6Handle,
                   &gEfiDns6ProtocolGuid,
                   (VOID **) &Dns6,
                   Private->Ip6Nic->ImageHandle,
                   Private->Controller,
                   EFI_OPEN_PROTOCOL_BY_DRIVER
                   );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   //
   // Configure DNS6 instance for the DNS server address and protocol.
   //
   ZeroMem (&Dns6ConfigData, sizeof (EFI_DNS6_CONFIG_DATA));
   Dns6ConfigData.DnsServerCount = (UINT32)DnsServerListCount;
   Dns6ConfigData.DnsServerList  = DnsServerList;
   Dns6ConfigData.EnableDnsCache = TRUE;
   Dns6ConfigData.Protocol       = EFI_IP_PROTO_UDP;
   IP6_COPY_ADDRESS (&Dns6ConfigData.StationIp,&Private->StationIp.v6);
   Status = Dns6->Configure (
                     Dns6,
                     &Dns6ConfigData
                     );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   Token.Status = EFI_NOT_READY;
   IsDone       = FALSE;
   //
   // Create event to set the  IsDone flag when name resolution is finished.
   //
   Status = gBS->CreateEvent (
                   EVT_NOTIFY_SIGNAL,
                   TPL_NOTIFY,
                   HttpBootCommonNotify,
                   &IsDone,
                   &Token.Event
                   );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   //
   // Start asynchronous name resolution.
   //
   Status = Dns6->HostNameToIp (Dns6, HostName, &Token);
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   while (!IsDone) {
     Dns6->Poll (Dns6);
   }

   //
   // Name resolution is done, check result.
   //
   Status = Token.Status;
   if (!EFI_ERROR (Status)) {
     if (Token.RspData.H2AData == NULL) {
       Status = EFI_DEVICE_ERROR;
       goto Exit;
     }
     if (Token.RspData.H2AData->IpCount == 0 || Token.RspData.H2AData->IpList == NULL) {
       Status = EFI_DEVICE_ERROR;
       goto Exit;
     }
     //
     // We just return the first IPv6 address from DNS protocol.
     //
     IP6_COPY_ADDRESS (IpAddress, Token.RspData.H2AData->IpList);
     Status = EFI_SUCCESS;
   }
 Exit:

   if (Token.Event != NULL) {
     gBS->CloseEvent (Token.Event);
   }
   if (Token.RspData.H2AData != NULL) {
     if (Token.RspData.H2AData->IpList != NULL) {
       FreePool (Token.RspData.H2AData->IpList);
     }
     FreePool (Token.RspData.H2AData);
   }

   if (Dns6 != NULL) {
     Dns6->Configure (Dns6, NULL);

     gBS->CloseProtocol (
            Dns6Handle,
            &gEfiDns6ProtocolGuid,
            Private->Ip6Nic->ImageHandle,
            Private->Controller
            );
   }

   if (Dns6Handle != NULL) {
     NetLibDestroyServiceChild (
       Private->Controller,
       Private->Ip6Nic->ImageHandle,
       &gEfiDns6ServiceBindingProtocolGuid,
       Dns6Handle
       );
   }

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

   return Status;
 }

 /**
   This function checks the HTTP(S) URI scheme.

   @param[in]    Uri              The pointer to the URI string.

   @retval EFI_SUCCESS            The URI scheme is valid.
   @retval EFI_INVALID_PARAMETER  The URI scheme is not HTTP or HTTPS.
   @retval EFI_ACCESS_DENIED      HTTP is disabled and the URI is HTTP.

 **/
 EFI_STATUS
 HttpBootCheckUriScheme (
   IN      CHAR8                  *Uri
   )
 {
   UINTN                Index;
   EFI_STATUS           Status;

   Status = EFI_SUCCESS;

   //
   // Convert the scheme to all lower case.
   //
   for (Index = 0; Index < AsciiStrLen (Uri); Index++) {
     if (Uri[Index] == ':') {
       break;
     }
     if (Uri[Index] >= 'A' && Uri[Index] <= 'Z') {
       Uri[Index] -= (CHAR8)('A' - 'a');
     }
   }

   //
   // Return EFI_INVALID_PARAMETER if the URI is not HTTP or HTTPS.
   //
   if ((AsciiStrnCmp (Uri, "http://", 7) != 0) && (AsciiStrnCmp (Uri, "https://", 8) != 0)) {
     DEBUG ((EFI_D_ERROR, "HttpBootCheckUriScheme: Invalid Uri.\n"));
     return EFI_INVALID_PARAMETER;
   }

   //
   // HTTP is disabled, return EFI_ACCESS_DENIED if the URI is HTTP.
   //
   if (!PcdGetBool (PcdAllowHttpConnections) && (AsciiStrnCmp (Uri, "http://", 7) == 0)) {
     DEBUG ((EFI_D_ERROR, "HttpBootCheckUriScheme: HTTP is disabled.\n"));
     return EFI_ACCESS_DENIED;
   }

   return Status;
 }

 /**
   Get the URI address string from the input device path.

   Caller need to free the buffer in the UriAddress pointer.

   @param[in]   FilePath         Pointer to the device path which contains a URI device path node.
   @param[out]  UriAddress       The URI address string extract from the device path.

   @retval EFI_SUCCESS            The URI string is returned.
   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory.

 **/
 EFI_STATUS
 HttpBootParseFilePath (
   IN     EFI_DEVICE_PATH_PROTOCOL     *FilePath,
      OUT CHAR8                        **UriAddress
   )
 {
   EFI_DEVICE_PATH_PROTOCOL  *TempDevicePath;
   URI_DEVICE_PATH           *UriDevicePath;
   CHAR8                     *Uri;
   UINTN                     UriStrLength;

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

   *UriAddress = NULL;

   //
   // Extract the URI address from the FilePath
   //
   TempDevicePath = FilePath;
   while (!IsDevicePathEnd (TempDevicePath)) {
     if ((DevicePathType (TempDevicePath) == MESSAGING_DEVICE_PATH) &&
         (DevicePathSubType (TempDevicePath) == MSG_URI_DP)) {
       UriDevicePath = (URI_DEVICE_PATH*) TempDevicePath;
       //
       // UEFI Spec doesn't require the URI to be a NULL-terminated string
       // So we allocate a new buffer and always append a '\0' to it.
       //
       UriStrLength = DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL);
       if (UriStrLength == 0) {
         //
         // return a NULL UriAddress if it's a empty URI device path node.
         //
         break;
       }
       Uri = AllocatePool (UriStrLength + 1);
       if (Uri == NULL) {
         return EFI_OUT_OF_RESOURCES;
       }
       CopyMem (Uri, UriDevicePath->Uri, DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL));
       Uri[DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL)] = '\0';

       *UriAddress = Uri;
     }
     TempDevicePath = NextDevicePathNode (TempDevicePath);
   }

   return EFI_SUCCESS;
 }

 /**
   This function returns the image type according to server replied HTTP message
   and also the image's URI info.

   @param[in]    Uri              The pointer to the image's URI string.
   @param[in]    UriParser        URI Parse result returned by NetHttpParseUrl().
   @param[in]    HeaderCount      Number of HTTP header structures in Headers list.
   @param[in]    Headers          Array containing list of HTTP headers.
   @param[out]   ImageType        The image type of the downloaded file.

   @retval EFI_SUCCESS            The image type is returned in ImageType.
   @retval EFI_INVALID_PARAMETER  ImageType, Uri or UriParser is NULL.
   @retval EFI_INVALID_PARAMETER  HeaderCount is not zero, and Headers is NULL.
   @retval EFI_NOT_FOUND          Failed to identify the image type.
   @retval Others                 Unexpected error happened.

 **/
 EFI_STATUS
 HttpBootCheckImageType (
   IN      CHAR8                  *Uri,
   IN      VOID                   *UriParser,
   IN      UINTN                  HeaderCount,
   IN      EFI_HTTP_HEADER        *Headers,
      OUT  HTTP_BOOT_IMAGE_TYPE   *ImageType
   )
 {
   EFI_STATUS            Status;
   EFI_HTTP_HEADER       *Header;
   CHAR8                 *FilePath;
   CHAR8                 *FilePost;

   if (Uri == NULL || UriParser == NULL || ImageType == NULL) {
     return EFI_INVALID_PARAMETER;
   }

   if (HeaderCount != 0 && Headers == NULL) {
     return EFI_INVALID_PARAMETER;
   }

   //
   // Determine the image type by the HTTP Content-Type header field first.
   //   "application/efi"         -> EFI Image
   //   "application/vnd.efi-iso" -> CD/DVD Image
   //   "application/vnd.efi-img" -> Virtual Disk Image
   //
   Header = HttpFindHeader (HeaderCount, Headers, HTTP_HEADER_CONTENT_TYPE);
   if (Header != NULL) {
     if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_EFI) == 0) {
       *ImageType = ImageTypeEfi;
       return EFI_SUCCESS;
     } else if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_ISO) == 0) {
       *ImageType = ImageTypeVirtualCd;
       return EFI_SUCCESS;
     } else if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_IMG) == 0) {
       *ImageType = ImageTypeVirtualDisk;
       return EFI_SUCCESS;
     }
   }

   //
   // Determine the image type by file extension:
   //   *.efi -> EFI Image
   //   *.iso -> CD/DVD Image
   //   *.img -> Virtual Disk Image
   //
   Status = HttpUrlGetPath (
              Uri,
              UriParser,
              &FilePath
              );
   if (EFI_ERROR (Status)) {
     return Status;
   }

   FilePost = FilePath + AsciiStrLen (FilePath) - 4;
   if (AsciiStrCmp (FilePost, ".efi") == 0) {
     *ImageType = ImageTypeEfi;
   } else if (AsciiStrCmp (FilePost, ".iso") == 0) {
     *ImageType = ImageTypeVirtualCd;
   } else if (AsciiStrCmp (FilePost, ".img") == 0) {
     *ImageType = ImageTypeVirtualDisk;
   } else {
     *ImageType = ImageTypeMax;
   }

   FreePool (FilePath);

   return (*ImageType < ImageTypeMax) ? EFI_SUCCESS : EFI_NOT_FOUND;
 }

 /**
   This function register the RAM disk info to the system.

   @param[in]       Private         The pointer to the driver's private data.
   @param[in]       BufferSize      The size of Buffer in bytes.
   @param[in]       Buffer          The base address of the RAM disk.
   @param[in]       ImageType       The image type of the file in Buffer.

   @retval EFI_SUCCESS              The RAM disk has been registered.
   @retval EFI_NOT_FOUND            No RAM disk protocol instances were found.
   @retval EFI_UNSUPPORTED          The ImageType is not supported.
   @retval Others                   Unexpected error happened.

 **/
 EFI_STATUS
 HttpBootRegisterRamDisk (
   IN  HTTP_BOOT_PRIVATE_DATA       *Private,
   IN  UINTN                        BufferSize,
   IN  VOID                         *Buffer,
   IN  HTTP_BOOT_IMAGE_TYPE         ImageType
   )
 {
   EFI_RAM_DISK_PROTOCOL      *RamDisk;
   EFI_STATUS                 Status;
   EFI_DEVICE_PATH_PROTOCOL   *DevicePath;
   EFI_GUID                   *RamDiskType;

   ASSERT (Private != NULL);
   ASSERT (Buffer != NULL);
   ASSERT (BufferSize != 0);

   Status = gBS->LocateProtocol (&gEfiRamDiskProtocolGuid, NULL, (VOID**) &RamDisk);
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "HTTP Boot: Couldn't find the RAM Disk protocol - %r\n", Status));
     return Status;
   }

   if (ImageType == ImageTypeVirtualCd) {
     RamDiskType = &gEfiVirtualCdGuid;
   } else if (ImageType == ImageTypeVirtualDisk) {
     RamDiskType = &gEfiVirtualDiskGuid;
   } else {
     return EFI_UNSUPPORTED;
   }

   Status = RamDisk->Register (
              (UINTN)Buffer,
              (UINT64)BufferSize,
              RamDiskType,
              Private->UsingIpv6 ? Private->Ip6Nic->DevicePath : Private->Ip4Nic->DevicePath,
              &DevicePath
              );
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "HTTP Boot: Failed to register RAM Disk - %r\n", Status));
   }

   return Status;
 }

 /**
   Indicate if the HTTP status code indicates a redirection.

   @param[in]  StatusCode      HTTP status code from server.

   @return                     TRUE if it's redirection.

 **/
 BOOLEAN
 HttpBootIsHttpRedirectStatusCode (
   IN   EFI_HTTP_STATUS_CODE        StatusCode
   )
 {
   if (StatusCode == HTTP_STATUS_301_MOVED_PERMANENTLY ||
       StatusCode == HTTP_STATUS_302_FOUND ||
       StatusCode == HTTP_STATUS_307_TEMPORARY_REDIRECT ||
       StatusCode == HTTP_STATUS_308_PERMANENT_REDIRECT) {
     return TRUE;
   }

   return FALSE;
 }
	/** @file
	Support functions implementation for UEFI HTTP boot driver.

	Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
	(C) Copyright 2016 - 2020 Hewlett Packard Enterprise Development LP<BR>
	SPDX-License-Identifier: BSD-2-Clause-Patent

	**/

	#include "HttpBootDxe.h"


	/**
	Get the Nic handle using any child handle in the IPv4 stack.

	@param[in] ControllerHandle Pointer to child handle over IPv4.

	@return NicHandle The pointer to the Nic handle.
	@return NULL Can't find the Nic handle.

	**/
	EFI_HANDLE
	HttpBootGetNicByIp4Children (
	IN EFI_HANDLE ControllerHandle
	)
	{
	EFI_HANDLE NicHandle;

	NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiHttpProtocolGuid);
	if (NicHandle == NULL) {
	NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiDhcp4ProtocolGuid);
	if (NicHandle == NULL) {
	return NULL;
	}
	}

	return NicHandle;
	}

	/**
	Get the Nic handle using any child handle in the IPv6 stack.

	@param[in] ControllerHandle Pointer to child handle over IPv6.

	@return NicHandle The pointer to the Nic handle.
	@return NULL Can't find the Nic handle.

	**/
	EFI_HANDLE
	HttpBootGetNicByIp6Children (
	IN EFI_HANDLE ControllerHandle
	)
	{
	EFI_HANDLE NicHandle;
	NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiHttpProtocolGuid);
	if (NicHandle == NULL) {
	NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiDhcp6ProtocolGuid);
	if (NicHandle == NULL) {
	return NULL;
	}
	}

	return NicHandle;
	}

	/**
	This function is to convert UINTN to ASCII string with the required formatting.

	@param[in] Number Numeric value to be converted.
	@param[in] Buffer The pointer to the buffer for ASCII string.
	@param[in] Length The length of the required format.

	**/
	VOID
	HttpBootUintnToAscDecWithFormat (
	IN UINTN Number,
	IN UINT8 *Buffer,
	IN INTN Length
	)
	{
	UINTN Remainder;

	for (; Length > 0; Length--) {
	Remainder = Number % 10;
	Number /= 10;
	Buffer[Length - 1] = (UINT8) ('0' + Remainder);
	}
	}

	/**
	This function is to display the IPv4 address.

	@param[in] Ip The pointer to the IPv4 address.

	**/
	VOID
	HttpBootShowIp4Addr (
	IN EFI_IPv4_ADDRESS *Ip
	)
	{
	UINTN Index;

	for (Index = 0; Index < 4; Index++) {
	AsciiPrint ("%d", Ip->Addr[Index]);
	if (Index < 3) {
	AsciiPrint (".");
	}
	}
	}

	/**
	This function is to display the IPv6 address.

	@param[in] Ip The pointer to the IPv6 address.

	**/
	VOID
	HttpBootShowIp6Addr (
	IN EFI_IPv6_ADDRESS *Ip
	)
	{
	UINTN Index;

	for (Index = 0; Index < 16; Index++) {

	if (Ip->Addr[Index] != 0) {
	AsciiPrint ("%x", Ip->Addr[Index]);
	}
	Index++;
	if (Index > 15) {
	return;
	}
	if (((Ip->Addr[Index] & 0xf0) == 0) && (Ip->Addr[Index - 1] != 0)) {
	AsciiPrint ("0");
	}
	AsciiPrint ("%x", Ip->Addr[Index]);
	if (Index < 15) {
	AsciiPrint (":");
	}
	}
	}

	/**
	This function is to display the HTTP error status.

	@param[in] StatusCode The status code value in HTTP message.

	**/
	VOID
	HttpBootPrintErrorMessage (
	EFI_HTTP_STATUS_CODE StatusCode
	)
	{
	AsciiPrint ("\n");

	switch (StatusCode) {
	case HTTP_STATUS_300_MULTIPLE_CHOICES:
	AsciiPrint ("\n Redirection: 300 Multiple Choices");
	break;

	case HTTP_STATUS_301_MOVED_PERMANENTLY:
	AsciiPrint ("\n Redirection: 301 Moved Permanently");
	break;

	case HTTP_STATUS_302_FOUND:
	AsciiPrint ("\n Redirection: 302 Found");
	break;

	case HTTP_STATUS_303_SEE_OTHER:
	AsciiPrint ("\n Redirection: 303 See Other");
	break;

	case HTTP_STATUS_304_NOT_MODIFIED:
	AsciiPrint ("\n Redirection: 304 Not Modified");
	break;

	case HTTP_STATUS_305_USE_PROXY:
	AsciiPrint ("\n Redirection: 305 Use Proxy");
	break;

	case HTTP_STATUS_307_TEMPORARY_REDIRECT:
	AsciiPrint ("\n Redirection: 307 Temporary Redirect");
	break;

	case HTTP_STATUS_308_PERMANENT_REDIRECT:
	AsciiPrint ("\n Redirection: 308 Permanent Redirect");
	break;

	case HTTP_STATUS_400_BAD_REQUEST:
	AsciiPrint ("\n Client Error: 400 Bad Request");
	break;

	case HTTP_STATUS_401_UNAUTHORIZED:
	AsciiPrint ("\n Client Error: 401 Unauthorized");
	break;

	case HTTP_STATUS_402_PAYMENT_REQUIRED:
	AsciiPrint ("\n Client Error: 402 Payment Required");
	break;

	case HTTP_STATUS_403_FORBIDDEN:
	AsciiPrint ("\n Client Error: 403 Forbidden");
	break;

	case HTTP_STATUS_404_NOT_FOUND:
	AsciiPrint ("\n Client Error: 404 Not Found");
	break;

	case HTTP_STATUS_405_METHOD_NOT_ALLOWED:
	AsciiPrint ("\n Client Error: 405 Method Not Allowed");
	break;

	case HTTP_STATUS_406_NOT_ACCEPTABLE:
	AsciiPrint ("\n Client Error: 406 Not Acceptable");
	break;

	case HTTP_STATUS_407_PROXY_AUTHENTICATION_REQUIRED:
	AsciiPrint ("\n Client Error: 407 Proxy Authentication Required");
	break;

	case HTTP_STATUS_408_REQUEST_TIME_OUT:
	AsciiPrint ("\n Client Error: 408 Request Timeout");
	break;

	case HTTP_STATUS_409_CONFLICT:
	AsciiPrint ("\n Client Error: 409 Conflict");
	break;

	case HTTP_STATUS_410_GONE:
	AsciiPrint ("\n Client Error: 410 Gone");
	break;

	case HTTP_STATUS_411_LENGTH_REQUIRED:
	AsciiPrint ("\n Client Error: 411 Length Required");
	break;

	case HTTP_STATUS_412_PRECONDITION_FAILED:
	AsciiPrint ("\n Client Error: 412 Precondition Failed");
	break;

	case HTTP_STATUS_413_REQUEST_ENTITY_TOO_LARGE:
	AsciiPrint ("\n Client Error: 413 Request Entity Too Large");
	break;

	case HTTP_STATUS_414_REQUEST_URI_TOO_LARGE:
	AsciiPrint ("\n Client Error: 414 Request URI Too Long");
	break;

	case HTTP_STATUS_415_UNSUPPORTED_MEDIA_TYPE:
	AsciiPrint ("\n Client Error: 415 Unsupported Media Type");
	break;

	case HTTP_STATUS_416_REQUESTED_RANGE_NOT_SATISFIED:
	AsciiPrint ("\n Client Error: 416 Requested Range Not Satisfiable");
	break;

	case HTTP_STATUS_417_EXPECTATION_FAILED:
	AsciiPrint ("\n Client Error: 417 Expectation Failed");
	break;

	case HTTP_STATUS_500_INTERNAL_SERVER_ERROR:
	AsciiPrint ("\n Server Error: 500 Internal Server Error");
	break;

	case HTTP_STATUS_501_NOT_IMPLEMENTED:
	AsciiPrint ("\n Server Error: 501 Not Implemented");
	break;

	case HTTP_STATUS_502_BAD_GATEWAY:
	AsciiPrint ("\n Server Error: 502 Bad Gateway");
	break;

	case HTTP_STATUS_503_SERVICE_UNAVAILABLE:
	AsciiPrint ("\n Server Error: 503 Service Unavailable");
	break;

	case HTTP_STATUS_504_GATEWAY_TIME_OUT:
	AsciiPrint ("\n Server Error: 504 Gateway Timeout");
	break;

	case HTTP_STATUS_505_HTTP_VERSION_NOT_SUPPORTED:
	AsciiPrint ("\n Server Error: 505 HTTP Version Not Supported");
	break;

	default: ;

	}
	}

	/**
	Notify the callback function when an event is triggered.

	@param[in] Event The triggered event.
	@param[in] Context The opaque parameter to the function.

	**/
	VOID
	EFIAPI
	HttpBootCommonNotify (
	IN EFI_EVENT Event,
	IN VOID *Context
	)
	{
	((BOOLEAN ) Context) = TRUE;
	}

	/**
	Retrieve the host address using the EFI_DNS6_PROTOCOL.

	@param[in] Private The pointer to the driver's private data.
	@param[in] HostName Pointer to buffer containing hostname.
	@param[out] IpAddress On output, pointer to buffer containing IPv6 address.

	@retval EFI_SUCCESS Operation succeeded.
	@retval EFI_DEVICE_ERROR An unexpected network error occurred.
	@retval Others Other errors as indicated.
	**/
	EFI_STATUS
	HttpBootDns (
	IN HTTP_BOOT_PRIVATE_DATA *Private,
	IN CHAR16 *HostName,
	OUT EFI_IPv6_ADDRESS *IpAddress
	)
	{
	EFI_STATUS Status;
	EFI_DNS6_PROTOCOL *Dns6;
	EFI_DNS6_CONFIG_DATA Dns6ConfigData;
	EFI_DNS6_COMPLETION_TOKEN Token;
	EFI_HANDLE Dns6Handle;
	EFI_IP6_CONFIG_PROTOCOL *Ip6Config;
	EFI_IPv6_ADDRESS *DnsServerList;
	UINTN DnsServerListCount;
	UINTN DataSize;
	BOOLEAN IsDone;

	DnsServerList = NULL;
	DnsServerListCount = 0;
	Dns6 = NULL;
	Dns6Handle = NULL;
	ZeroMem (&Token, sizeof (EFI_DNS6_COMPLETION_TOKEN));

	//
	// Get DNS server list from EFI IPv6 Configuration protocol.
	//
	Status = gBS->HandleProtocol (Private->Controller, &gEfiIp6ConfigProtocolGuid, (VOID **) &Ip6Config);
	if (!EFI_ERROR (Status)) {
	//
	// Get the required size.
	//
	DataSize = 0;
	Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, NULL);
	if (Status == EFI_BUFFER_TOO_SMALL) {
	DnsServerList = AllocatePool (DataSize);
	if (DnsServerList == NULL) {
	return EFI_OUT_OF_RESOURCES;
	}

	Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, DnsServerList);
	if (EFI_ERROR (Status)) {
	FreePool (DnsServerList);
	DnsServerList = NULL;
	} else {
	DnsServerListCount = DataSize / sizeof (EFI_IPv6_ADDRESS);
	}
	}
	}
	//
	// Create a DNSv6 child instance and get the protocol.
	//
	Status = NetLibCreateServiceChild (
	Private->Controller,
	Private->Ip6Nic->ImageHandle,
	&gEfiDns6ServiceBindingProtocolGuid,
	&Dns6Handle
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	Status = gBS->OpenProtocol (
	Dns6Handle,
	&gEfiDns6ProtocolGuid,
	(VOID **) &Dns6,
	Private->Ip6Nic->ImageHandle,
	Private->Controller,
	EFI_OPEN_PROTOCOL_BY_DRIVER
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	//
	// Configure DNS6 instance for the DNS server address and protocol.
	//
	ZeroMem (&Dns6ConfigData, sizeof (EFI_DNS6_CONFIG_DATA));
	Dns6ConfigData.DnsServerCount = (UINT32)DnsServerListCount;
	Dns6ConfigData.DnsServerList = DnsServerList;
	Dns6ConfigData.EnableDnsCache = TRUE;
	Dns6ConfigData.Protocol = EFI_IP_PROTO_UDP;
	IP6_COPY_ADDRESS (&Dns6ConfigData.StationIp,&Private->StationIp.v6);
	Status = Dns6->Configure (
	Dns6,
	&Dns6ConfigData
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	Token.Status = EFI_NOT_READY;
	IsDone = FALSE;
	//
	// Create event to set the IsDone flag when name resolution is finished.
	//
	Status = gBS->CreateEvent (
	EVT_NOTIFY_SIGNAL,
	TPL_NOTIFY,
	HttpBootCommonNotify,
	&IsDone,
	&Token.Event
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	//
	// Start asynchronous name resolution.
	//
	Status = Dns6->HostNameToIp (Dns6, HostName, &Token);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	while (!IsDone) {
	Dns6->Poll (Dns6);
	}

	//
	// Name resolution is done, check result.
	//
	Status = Token.Status;
	if (!EFI_ERROR (Status)) {
	if (Token.RspData.H2AData == NULL) {
	Status = EFI_DEVICE_ERROR;
	goto Exit;
	}
	if (Token.RspData.H2AData->IpCount == 0 \|\| Token.RspData.H2AData->IpList == NULL) {
	Status = EFI_DEVICE_ERROR;
	goto Exit;
	}
	//
	// We just return the first IPv6 address from DNS protocol.
	//
	IP6_COPY_ADDRESS (IpAddress, Token.RspData.H2AData->IpList);
	Status = EFI_SUCCESS;
	}
	Exit:

	if (Token.Event != NULL) {
	gBS->CloseEvent (Token.Event);
	}
	if (Token.RspData.H2AData != NULL) {
	if (Token.RspData.H2AData->IpList != NULL) {
	FreePool (Token.RspData.H2AData->IpList);
	}
	FreePool (Token.RspData.H2AData);
	}

	if (Dns6 != NULL) {
	Dns6->Configure (Dns6, NULL);

	gBS->CloseProtocol (
	Dns6Handle,
	&gEfiDns6ProtocolGuid,
	Private->Ip6Nic->ImageHandle,
	Private->Controller
	);
	}

	if (Dns6Handle != NULL) {
	NetLibDestroyServiceChild (
	Private->Controller,
	Private->Ip6Nic->ImageHandle,
	&gEfiDns6ServiceBindingProtocolGuid,
	Dns6Handle
	);
	}

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

	return Status;
	}

	/**
	This function checks the HTTP(S) URI scheme.

	@param[in] Uri The pointer to the URI string.

	@retval EFI_SUCCESS The URI scheme is valid.
	@retval EFI_INVALID_PARAMETER The URI scheme is not HTTP or HTTPS.
	@retval EFI_ACCESS_DENIED HTTP is disabled and the URI is HTTP.

	**/
	EFI_STATUS
	HttpBootCheckUriScheme (
	IN CHAR8 *Uri
	)
	{
	UINTN Index;
	EFI_STATUS Status;

	Status = EFI_SUCCESS;

	//
	// Convert the scheme to all lower case.
	//
	for (Index = 0; Index < AsciiStrLen (Uri); Index++) {
	if (Uri[Index] == ':') {
	break;
	}
	if (Uri[Index] >= 'A' && Uri[Index] <= 'Z') {
	Uri[Index] -= (CHAR8)('A' - 'a');
	}
	}

	//
	// Return EFI_INVALID_PARAMETER if the URI is not HTTP or HTTPS.
	//
	if ((AsciiStrnCmp (Uri, "http://", 7) != 0) && (AsciiStrnCmp (Uri, "https://", 8) != 0)) {
	DEBUG ((EFI_D_ERROR, "HttpBootCheckUriScheme: Invalid Uri.\n"));
	return EFI_INVALID_PARAMETER;
	}

	//
	// HTTP is disabled, return EFI_ACCESS_DENIED if the URI is HTTP.
	//
	if (!PcdGetBool (PcdAllowHttpConnections) && (AsciiStrnCmp (Uri, "http://", 7) == 0)) {
	DEBUG ((EFI_D_ERROR, "HttpBootCheckUriScheme: HTTP is disabled.\n"));
	return EFI_ACCESS_DENIED;
	}

	return Status;
	}

	/**
	Get the URI address string from the input device path.

	Caller need to free the buffer in the UriAddress pointer.

	@param[in] FilePath Pointer to the device path which contains a URI device path node.
	@param[out] UriAddress The URI address string extract from the device path.

	@retval EFI_SUCCESS The URI string is returned.
	@retval EFI_OUT_OF_RESOURCES Failed to allocate memory.

	**/
	EFI_STATUS
	HttpBootParseFilePath (
	IN EFI_DEVICE_PATH_PROTOCOL *FilePath,
	OUT CHAR8 **UriAddress
	)
	{
	EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
	URI_DEVICE_PATH *UriDevicePath;
	CHAR8 *Uri;
	UINTN UriStrLength;

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

	*UriAddress = NULL;

	//
	// Extract the URI address from the FilePath
	//
	TempDevicePath = FilePath;
	while (!IsDevicePathEnd (TempDevicePath)) {
	if ((DevicePathType (TempDevicePath) == MESSAGING_DEVICE_PATH) &&
	(DevicePathSubType (TempDevicePath) == MSG_URI_DP)) {
	UriDevicePath = (URI_DEVICE_PATH*) TempDevicePath;
	//
	// UEFI Spec doesn't require the URI to be a NULL-terminated string
	// So we allocate a new buffer and always append a '\0' to it.
	//
	UriStrLength = DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL);
	if (UriStrLength == 0) {
	//
	// return a NULL UriAddress if it's a empty URI device path node.
	//
	break;
	}
	Uri = AllocatePool (UriStrLength + 1);
	if (Uri == NULL) {
	return EFI_OUT_OF_RESOURCES;
	}
	CopyMem (Uri, UriDevicePath->Uri, DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL));
	Uri[DevicePathNodeLength (UriDevicePath) - sizeof(EFI_DEVICE_PATH_PROTOCOL)] = '\0';

	*UriAddress = Uri;
	}
	TempDevicePath = NextDevicePathNode (TempDevicePath);
	}

	return EFI_SUCCESS;
	}

	/**
	This function returns the image type according to server replied HTTP message
	and also the image's URI info.

	@param[in] Uri The pointer to the image's URI string.
	@param[in] UriParser URI Parse result returned by NetHttpParseUrl().
	@param[in] HeaderCount Number of HTTP header structures in Headers list.
	@param[in] Headers Array containing list of HTTP headers.
	@param[out] ImageType The image type of the downloaded file.

	@retval EFI_SUCCESS The image type is returned in ImageType.
	@retval EFI_INVALID_PARAMETER ImageType, Uri or UriParser is NULL.
	@retval EFI_INVALID_PARAMETER HeaderCount is not zero, and Headers is NULL.
	@retval EFI_NOT_FOUND Failed to identify the image type.
	@retval Others Unexpected error happened.

	**/
	EFI_STATUS
	HttpBootCheckImageType (
	IN CHAR8 *Uri,
	IN VOID *UriParser,
	IN UINTN HeaderCount,
	IN EFI_HTTP_HEADER *Headers,
	OUT HTTP_BOOT_IMAGE_TYPE *ImageType
	)
	{
	EFI_STATUS Status;
	EFI_HTTP_HEADER *Header;
	CHAR8 *FilePath;
	CHAR8 *FilePost;

	if (Uri == NULL \|\| UriParser == NULL \|\| ImageType == NULL) {
	return EFI_INVALID_PARAMETER;
	}

	if (HeaderCount != 0 && Headers == NULL) {
	return EFI_INVALID_PARAMETER;
	}

	//
	// Determine the image type by the HTTP Content-Type header field first.
	// "application/efi" -> EFI Image
	// "application/vnd.efi-iso" -> CD/DVD Image
	// "application/vnd.efi-img" -> Virtual Disk Image
	//
	Header = HttpFindHeader (HeaderCount, Headers, HTTP_HEADER_CONTENT_TYPE);
	if (Header != NULL) {
	if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_EFI) == 0) {
	*ImageType = ImageTypeEfi;
	return EFI_SUCCESS;
	} else if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_ISO) == 0) {
	*ImageType = ImageTypeVirtualCd;
	return EFI_SUCCESS;
	} else if (AsciiStriCmp (Header->FieldValue, HTTP_CONTENT_TYPE_APP_IMG) == 0) {
	*ImageType = ImageTypeVirtualDisk;
	return EFI_SUCCESS;
	}
	}

	//
	// Determine the image type by file extension:
	// *.efi -> EFI Image
	// *.iso -> CD/DVD Image
	// *.img -> Virtual Disk Image
	//
	Status = HttpUrlGetPath (
	Uri,
	UriParser,
	&FilePath
	);
	if (EFI_ERROR (Status)) {
	return Status;
	}

	FilePost = FilePath + AsciiStrLen (FilePath) - 4;
	if (AsciiStrCmp (FilePost, ".efi") == 0) {
	*ImageType = ImageTypeEfi;
	} else if (AsciiStrCmp (FilePost, ".iso") == 0) {
	*ImageType = ImageTypeVirtualCd;
	} else if (AsciiStrCmp (FilePost, ".img") == 0) {
	*ImageType = ImageTypeVirtualDisk;
	} else {
	*ImageType = ImageTypeMax;
	}

	FreePool (FilePath);

	return (*ImageType < ImageTypeMax) ? EFI_SUCCESS : EFI_NOT_FOUND;
	}

	/**
	This function register the RAM disk info to the system.

	@param[in] Private The pointer to the driver's private data.
	@param[in] BufferSize The size of Buffer in bytes.
	@param[in] Buffer The base address of the RAM disk.
	@param[in] ImageType The image type of the file in Buffer.

	@retval EFI_SUCCESS The RAM disk has been registered.
	@retval EFI_NOT_FOUND No RAM disk protocol instances were found.
	@retval EFI_UNSUPPORTED The ImageType is not supported.
	@retval Others Unexpected error happened.

	**/
	EFI_STATUS
	HttpBootRegisterRamDisk (
	IN HTTP_BOOT_PRIVATE_DATA *Private,
	IN UINTN BufferSize,
	IN VOID *Buffer,
	IN HTTP_BOOT_IMAGE_TYPE ImageType
	)
	{
	EFI_RAM_DISK_PROTOCOL *RamDisk;
	EFI_STATUS Status;
	EFI_DEVICE_PATH_PROTOCOL *DevicePath;
	EFI_GUID *RamDiskType;

	ASSERT (Private != NULL);
	ASSERT (Buffer != NULL);
	ASSERT (BufferSize != 0);

	Status = gBS->LocateProtocol (&gEfiRamDiskProtocolGuid, NULL, (VOID**) &RamDisk);
	if (EFI_ERROR (Status)) {
	DEBUG ((EFI_D_ERROR, "HTTP Boot: Couldn't find the RAM Disk protocol - %r\n", Status));
	return Status;
	}

	if (ImageType == ImageTypeVirtualCd) {
	RamDiskType = &gEfiVirtualCdGuid;
	} else if (ImageType == ImageTypeVirtualDisk) {
	RamDiskType = &gEfiVirtualDiskGuid;
	} else {
	return EFI_UNSUPPORTED;
	}

	Status = RamDisk->Register (
	(UINTN)Buffer,
	(UINT64)BufferSize,
	RamDiskType,
	Private->UsingIpv6 ? Private->Ip6Nic->DevicePath : Private->Ip4Nic->DevicePath,
	&DevicePath
	);
	if (EFI_ERROR (Status)) {
	DEBUG ((EFI_D_ERROR, "HTTP Boot: Failed to register RAM Disk - %r\n", Status));
	}

	return Status;
	}

	/**
	Indicate if the HTTP status code indicates a redirection.

	@param[in] StatusCode HTTP status code from server.

	@return TRUE if it's redirection.

	**/
	BOOLEAN
	HttpBootIsHttpRedirectStatusCode (
	IN EFI_HTTP_STATUS_CODE StatusCode
	)
	{
	if (StatusCode == HTTP_STATUS_301_MOVED_PERMANENTLY \|\|
	StatusCode == HTTP_STATUS_302_FOUND \|\|
	StatusCode == HTTP_STATUS_307_TEMPORARY_REDIRECT \|\|
	StatusCode == HTTP_STATUS_308_PERMANENT_REDIRECT) {
	return TRUE;
	}

	return FALSE;
	}