Network/IScsiDxe/IScsiMisc.c

/** @file
  Miscellaneous routines for iSCSI driver.

Copyright (c) 2004 - 2015, Intel Corporation. All rights reserved.<BR>
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.

**/

#include "IScsiImpl.h"

GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8  IScsiHexString[] = "0123456789ABCDEFabcdef";

/**
  Removes (trims) specified leading and trailing characters from a string.

  @param[in, out]  Str  Pointer to the null-terminated string to be trimmed. On return,
                        Str will hold the trimmed string.

  @param[in]      CharC Character will be trimmed from str.
**/
VOID
StrTrim (
  IN OUT CHAR16   *Str,
  IN     CHAR16   CharC
  )
{
  CHAR16  *Pointer1;
  CHAR16  *Pointer2;

  if (*Str == 0) {
    return;
  }

  //
  // Trim off the leading and trailing characters c
  //
  for (Pointer1 = Str; (*Pointer1 != 0) && (*Pointer1 == CharC); Pointer1++) {
    ;
  }

  Pointer2 = Str;
  if (Pointer2 == Pointer1) {
    while (*Pointer1 != 0) {
      Pointer2++;
      Pointer1++;
    }
  } else {
    while (*Pointer1 != 0) {
    *Pointer2 = *Pointer1;
    Pointer1++;
    Pointer2++;
    }
    *Pointer2 = 0;
  }


  for (Pointer1 = Str + StrLen(Str) - 1; Pointer1 >= Str && *Pointer1 == CharC; Pointer1--) {
    ;
  }
  if  (Pointer1 !=  Str + StrLen(Str) - 1) {
    *(Pointer1 + 1) = 0;
  }
}

/**
  Calculate the prefix length of the IPv4 subnet mask.

  @param[in]  SubnetMask The IPv4 subnet mask.

  @return The prefix length of the subnet mask.
  @retval 0 Other errors as indicated.
**/
UINT8
IScsiGetSubnetMaskPrefixLength (
  IN EFI_IPv4_ADDRESS  *SubnetMask
  )
{
  UINT8   Len;
  UINT32  ReverseMask;

  //
  // The SubnetMask is in network byte order.
  //
  ReverseMask = (SubnetMask->Addr[0] << 24) | (SubnetMask->Addr[1] << 16) | (SubnetMask->Addr[2] << 8) | (SubnetMask->Addr[3]);

  //
  // Reverse it.
  //
  ReverseMask = ~ReverseMask;

  if ((ReverseMask & (ReverseMask + 1)) != 0) {
    return 0;
  }

  Len = 0;

  while (ReverseMask != 0) {
    ReverseMask = ReverseMask >> 1;
    Len++;
  }

  return (UINT8) (32 - Len);
}

/**
  Convert the hexadecimal encoded LUN string into the 64-bit LUN.

  @param[in]   Str             The hexadecimal encoded LUN string.
  @param[out]  Lun             Storage to return the 64-bit LUN.

  @retval EFI_SUCCESS           The 64-bit LUN is stored in Lun.
  @retval EFI_INVALID_PARAMETER The string is malformatted.
**/
EFI_STATUS
IScsiAsciiStrToLun (
  IN  CHAR8  *Str,
  OUT UINT8  *Lun
  )
{
  UINTN   Index, IndexValue, IndexNum, SizeStr;
  CHAR8   TemStr[2];
  UINT8   TemValue;
  UINT16  Value[4];

  ZeroMem (Lun, 8);
  ZeroMem (TemStr, 2);
  ZeroMem ((UINT8 *) Value, sizeof (Value));
  SizeStr    = AsciiStrLen (Str);
  IndexValue = 0;
  IndexNum   = 0;

  for (Index = 0; Index < SizeStr; Index ++) {
    TemStr[0] = Str[Index];
    TemValue = (UINT8) AsciiStrHexToUint64 (TemStr);
    if (TemValue == 0 && TemStr[0] != '0') {
      if ((TemStr[0] != '-') || (IndexNum == 0)) {
        //
        // Invalid Lun Char
        //
        return EFI_INVALID_PARAMETER;
      }
    }

    if ((TemValue == 0) && (TemStr[0] == '-')) {
      //
      // Next Lun value
      //
      if (++IndexValue >= 4) {
        //
        // Max 4 Lun value
        //
        return EFI_INVALID_PARAMETER;
      }
      //
      // Restart str index for the next lun value
      //
      IndexNum = 0;
      continue;
    }

    if (++IndexNum > 4) {
      //
      // Each Lun Str can't exceed size 4, because it will be as UINT16 value
      //
      return EFI_INVALID_PARAMETER;
    }

    //
    // Combine UINT16 value
    //
    Value[IndexValue] = (UINT16) ((Value[IndexValue] << 4) + TemValue);
  }

  for (Index = 0; Index <= IndexValue; Index ++) {
    *((UINT16 *) &Lun[Index * 2]) =  HTONS (Value[Index]);
  }

  return EFI_SUCCESS;
}

/**
  Convert the 64-bit LUN into the hexadecimal encoded LUN string.

  @param[in]   Lun The 64-bit LUN.
  @param[out]  Str The storage to return the hexadecimal encoded LUN string.
**/
VOID
IScsiLunToUnicodeStr (
  IN UINT8    *Lun,
  OUT CHAR16  *Str
  )
{
  UINTN   Index;
  CHAR16  *TempStr;

  TempStr = Str;

  for (Index = 0; Index < 4; Index++) {

    if ((Lun[2 * Index] | Lun[2 * Index + 1]) == 0) {
      CopyMem(TempStr, L"0-", sizeof (L"0-"));
    } else {
      TempStr[0]  = (CHAR16) IScsiHexString[Lun[2 * Index] >> 4];
      TempStr[1]  = (CHAR16) IScsiHexString[Lun[2 * Index] & 0x0F];
      TempStr[2]  = (CHAR16) IScsiHexString[Lun[2 * Index + 1] >> 4];
      TempStr[3]  = (CHAR16) IScsiHexString[Lun[2 * Index + 1] & 0x0F];
      TempStr[4]  = L'-';
      TempStr[5]  = 0;

      StrTrim (TempStr, L'0');
    }

    TempStr += StrLen (TempStr);
  }

  ASSERT (StrLen(Str) >= 1);
  Str[StrLen (Str) - 1] = 0;

  for (Index = StrLen (Str) - 1; Index > 1; Index = Index - 2) {
    if ((Str[Index] == L'0') && (Str[Index - 1] == L'-')) {
      Str[Index - 1] = 0;
    } else {
      break;
    }
  }
}

/**
  Convert the ASCII string into a UNICODE string.

  @param[in]   Source      The ASCII string.
  @param[out]  Destination The storage to return the UNICODE string.

  @return CHAR16 *         Pointer to the UNICODE string.
**/
CHAR16 *
IScsiAsciiStrToUnicodeStr (
  IN  CHAR8   *Source,
  OUT CHAR16  *Destination
  )
{
  ASSERT (Destination != NULL);
  ASSERT (Source != NULL);

  while (*Source != '\0') {
    *(Destination++) = (CHAR16) *(Source++);
  }

  *Destination = '\0';

  return Destination;
}

/**
  Convert the UNICODE string into an ASCII string.

  @param[in]  Source       The UNICODE string.
  @param[out] Destination  The storage to return the ASCII string.

  @return CHAR8 *          Pointer to the ASCII string.
**/
CHAR8 *
IScsiUnicodeStrToAsciiStr (
  IN  CHAR16  *Source,
  OUT CHAR8   *Destination
  )
{
  ASSERT (Destination != NULL);
  ASSERT (Source != NULL);

  while (*Source != '\0') {
    //
    // If any Unicode characters in Source contain
    // non-zero value in the upper 8 bits, then ASSERT().
    //
    ASSERT (*Source < 0x100);
    *(Destination++) = (CHAR8) *(Source++);
  }

  *Destination = '\0';

  return Destination;
}

/**
  Convert the decimal dotted IPv4 address into the binary IPv4 address.

  @param[in]   Str             The UNICODE string.
  @param[out]  Ip              The storage to return the ASCII string.

  @retval EFI_SUCCESS           The binary IP address is returned in Ip.
  @retval EFI_INVALID_PARAMETER The IP string is malformatted.
**/
EFI_STATUS
IScsiAsciiStrToIp (
  IN  CHAR8             *Str,
  OUT EFI_IPv4_ADDRESS  *Ip
  )
{
  UINTN Index;
  UINTN Number;

  Index = 0;

  while (*Str != 0) {

    if (Index > 3) {
      return EFI_INVALID_PARAMETER;
    }

    Number = 0;
    while (NET_IS_DIGIT (*Str)) {
      Number = Number * 10 + (*Str - '0');
      Str++;
    }

    if (Number > 0xFF) {
      return EFI_INVALID_PARAMETER;
    }

    Ip->Addr[Index] = (UINT8) Number;

    if ((*Str != '\0') && (*Str != '.')) {
      //
      // The current character should be either the NULL terminator or
      // the dot delimiter.
      //
      return EFI_INVALID_PARAMETER;
    }

    if (*Str == '.') {
      //
      // Skip the delimiter.
      //
      Str++;
    }

    Index++;
  }

  if (Index != 4) {
    return EFI_INVALID_PARAMETER;
  }

  return EFI_SUCCESS;
}

/**
  Convert the mac address into a hexadecimal encoded "-" seperated string.

  @param[in]  Mac     The mac address.
  @param[in]  Len     Length in bytes of the mac address.
  @param[in]  VlanId  VLAN ID of the network device.
  @param[out] Str     The storage to return the mac string.
**/
VOID
IScsiMacAddrToStr (
  IN  EFI_MAC_ADDRESS  *Mac,
  IN  UINT32           Len,
  IN  UINT16           VlanId,
  OUT CHAR16           *Str
  )
{
  UINT32  Index;
  CHAR16  *String;

  for (Index = 0; Index < Len; Index++) {
    Str[3 * Index]      = (CHAR16) IScsiHexString[(Mac->Addr[Index] >> 4) & 0x0F];
    Str[3 * Index + 1]  = (CHAR16) IScsiHexString[Mac->Addr[Index] & 0x0F];
    Str[3 * Index + 2]  = L'-';
  }

  String = &Str[3 * Index - 1] ;
  if (VlanId != 0) {
    String += UnicodeSPrint (String, 6 * sizeof (CHAR16), L"\\%04x", (UINTN) VlanId);
  }

  *String = L'\0';
}

/**
  Convert the binary encoded buffer into a hexadecimal encoded string.

  @param[in]       BinBuffer   The buffer containing the binary data.
  @param[in]       BinLength   Length of the binary buffer.
  @param[in, out]  HexStr      Pointer to the string.
  @param[in, out]  HexLength   The length of the string.

  @retval EFI_SUCCESS          The binary data is converted to the hexadecimal string
                               and the length of the string is updated.
  @retval EFI_BUFFER_TOO_SMALL The string is too small.
  @retval EFI_INVALID_PARAMETER The IP string is malformatted.
**/
EFI_STATUS
IScsiBinToHex (
  IN     UINT8  *BinBuffer,
  IN     UINT32 BinLength,
  IN OUT CHAR8  *HexStr,
  IN OUT UINT32 *HexLength
  )
{
  UINTN Index;

  if ((HexStr == NULL) || (BinBuffer == NULL) || (BinLength == 0)) {
    return EFI_INVALID_PARAMETER;
  }

  if (((*HexLength) - 3) < BinLength * 2) {
    *HexLength = BinLength * 2 + 3;
    return EFI_BUFFER_TOO_SMALL;
  }

  *HexLength = BinLength * 2 + 3;
  //
  // Prefix for Hex String
  //
  HexStr[0] = '0';
  HexStr[1] = 'x';

  for (Index = 0; Index < BinLength; Index++) {
    HexStr[Index * 2 + 2] = IScsiHexString[BinBuffer[Index] >> 4];
    HexStr[Index * 2 + 3] = IScsiHexString[BinBuffer[Index] & 0x0F];
  }

  HexStr[Index * 2 + 2] = '\0';

  return EFI_SUCCESS;
}

/**
  Convert the hexadecimal string into a binary encoded buffer.

  @param[in, out]  BinBuffer   The binary buffer.
  @param[in, out]  BinLength   Length of the binary buffer.
  @param[in]       HexStr      The hexadecimal string.

  @retval EFI_SUCCESS          The hexadecimal string is converted into a binary
                               encoded buffer.
  @retval EFI_BUFFER_TOO_SMALL The binary buffer is too small to hold the converted data.
**/
EFI_STATUS
IScsiHexToBin (
  IN OUT UINT8  *BinBuffer,
  IN OUT UINT32 *BinLength,
  IN     CHAR8  *HexStr
  )
{
  UINTN   Index;
  UINTN   Length;
  UINT8   Digit;
  CHAR8   TemStr[2];

  ZeroMem (TemStr, sizeof (TemStr));

  //
  // Find out how many hex characters the string has.
  //
  if ((HexStr[0] == '0') && ((HexStr[1] == 'x') || (HexStr[1] == 'X'))) {
    HexStr += 2;
  }

  Length = AsciiStrLen (HexStr);

  for (Index = 0; Index < Length; Index ++) {
    TemStr[0] = HexStr[Index];
    Digit = (UINT8) AsciiStrHexToUint64 (TemStr);
    if (Digit == 0 && TemStr[0] != '0') {
      //
      // Invalid Lun Char
      //
      break;
    }
    if ((Index & 1) == 0) {
      BinBuffer [Index/2] = Digit;
    } else {
      BinBuffer [Index/2] = (UINT8) ((BinBuffer [Index/2] << 4) + Digit);
    }
  }

  *BinLength = (UINT32) ((Index + 1)/2);

  return EFI_SUCCESS;
}

/**
  Generate random numbers.

  @param[in, out]  Rand       The buffer to contain random numbers.
  @param[in]       RandLength The length of the Rand buffer.
**/
VOID
IScsiGenRandom (
  IN OUT UINT8  *Rand,
  IN     UINTN  RandLength
  )
{
  UINT32  Random;

  while (RandLength > 0) {
    Random  = NET_RANDOM (NetRandomInitSeed ());
    *Rand++ = (UINT8) (Random);
    RandLength--;
  }
}

/**
  Create the iSCSI driver data..

  @param[in] Image      The handle of the driver image.
  @param[in] Controller The handle of the controller.

  @return The iSCSI driver data created.
  @retval NULL Other errors as indicated.
**/
ISCSI_DRIVER_DATA *
IScsiCreateDriverData (
  IN EFI_HANDLE  Image,
  IN EFI_HANDLE  Controller
  )
{
  ISCSI_DRIVER_DATA *Private;
  EFI_STATUS        Status;

  Private = AllocateZeroPool (sizeof (ISCSI_DRIVER_DATA));
  if (Private == NULL) {
    return NULL;
  }

  Private->Signature  = ISCSI_DRIVER_DATA_SIGNATURE;
  Private->Image      = Image;
  Private->Controller = Controller;

  //
  // Create an event to be signal when the BS to RT transition is triggerd so
  // as to abort the iSCSI session.
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  IScsiOnExitBootService,
                  Private,
                  &gEfiEventExitBootServicesGuid,
                  &Private->ExitBootServiceEvent
                  );
  if (EFI_ERROR (Status)) {
    FreePool (Private);
    return NULL;
  }

  CopyMem(&Private->IScsiExtScsiPassThru, &gIScsiExtScsiPassThruProtocolTemplate, sizeof(EFI_EXT_SCSI_PASS_THRU_PROTOCOL));

  //
  // 0 is designated to the TargetId, so use another value for the AdapterId.
  //
  Private->ExtScsiPassThruMode.AdapterId = 2;
  Private->ExtScsiPassThruMode.Attributes = EFI_EXT_SCSI_PASS_THRU_ATTRIBUTES_PHYSICAL | EFI_EXT_SCSI_PASS_THRU_ATTRIBUTES_LOGICAL;
  Private->ExtScsiPassThruMode.IoAlign  = 4;
  Private->IScsiExtScsiPassThru.Mode    = &Private->ExtScsiPassThruMode;

  //
  // Install the Ext SCSI PASS THRU protocol.
  //
  Status = gBS->InstallProtocolInterface (
                  &Private->ExtScsiPassThruHandle,
                  &gEfiExtScsiPassThruProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &Private->IScsiExtScsiPassThru
                  );
  if (EFI_ERROR (Status)) {
    gBS->CloseEvent (Private->ExitBootServiceEvent);
    FreePool (Private);

    return NULL;
  }

  IScsiSessionInit (&Private->Session, FALSE);

  return Private;
}

/**
  Clean the iSCSI driver data.

  @param[in]  Private The iSCSI driver data.
**/
VOID
IScsiCleanDriverData (
  IN ISCSI_DRIVER_DATA  *Private
  )
{
  if (Private->DevicePath != NULL) {
    gBS->UninstallProtocolInterface (
          Private->ExtScsiPassThruHandle,
          &gEfiDevicePathProtocolGuid,
          Private->DevicePath
          );

    FreePool (Private->DevicePath);
  }

  if (Private->ExtScsiPassThruHandle != NULL) {
    gBS->UninstallProtocolInterface (
          Private->ExtScsiPassThruHandle,
          &gEfiExtScsiPassThruProtocolGuid,
          &Private->IScsiExtScsiPassThru
          );
  }

  gBS->CloseEvent (Private->ExitBootServiceEvent);

  FreePool (Private);
}

/**
  Check wheather the Controller is configured to use DHCP protocol.

  @param[in]  Controller           The handle of the controller.

  @retval TRUE                     The handle of the controller need the Dhcp protocol.
  @retval FALSE                    The handle of the controller does not need the Dhcp protocol.

**/
BOOLEAN
IScsiDhcpIsConfigured (
  IN EFI_HANDLE  Controller
  )
{
  EFI_STATUS                  Status;
  EFI_MAC_ADDRESS             MacAddress;
  UINTN                       HwAddressSize;
  UINT16                      VlanId;
  CHAR16                      MacString[70];
  ISCSI_SESSION_CONFIG_NVDATA *ConfigDataTmp;

  //
  // Get the mac string, it's the name of various variable
  //
  Status = NetLibGetMacAddress (Controller, &MacAddress, &HwAddressSize);
  if (EFI_ERROR (Status)) {
    return FALSE;
  }
  VlanId = NetLibGetVlanId (Controller);
  IScsiMacAddrToStr (&MacAddress, (UINT32) HwAddressSize, VlanId, MacString);

  //
  // Get the normal configuration.
  //
  Status = GetVariable2 (
             MacString,
             &gEfiIScsiInitiatorNameProtocolGuid,
             (VOID**)&ConfigDataTmp,
             NULL
             );
  if (ConfigDataTmp == NULL || EFI_ERROR (Status)) {
    return FALSE;
  }

  if (ConfigDataTmp->Enabled && ConfigDataTmp->InitiatorInfoFromDhcp) {
    FreePool (ConfigDataTmp);
    return TRUE;
  }

  FreePool (ConfigDataTmp);
  return FALSE;
}

/**
  Get the various configuration data of this iSCSI instance.

  @param[in]  Private   The iSCSI driver data.

  @retval EFI_SUCCESS   The configuration of this instance is got.
  @retval EFI_ABORTED   The operation was aborted.
  @retval Others        Other errors as indicated.
**/
EFI_STATUS
IScsiGetConfigData (
  IN ISCSI_DRIVER_DATA  *Private
  )
{
  EFI_STATUS                  Status;
  ISCSI_SESSION               *Session;
  UINTN                       BufferSize;
  EFI_MAC_ADDRESS             MacAddress;
  UINTN                       HwAddressSize;
  UINT16                      VlanId;
  CHAR16                      MacString[70];

  //
  // get the iSCSI Initiator Name
  //
  Session                       = &Private->Session;
  Session->InitiatorNameLength  = ISCSI_NAME_MAX_SIZE;
  Status = gIScsiInitiatorName.Get (
                                &gIScsiInitiatorName,
                                &Session->InitiatorNameLength,
                                Session->InitiatorName
                                );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Get the mac string, it's the name of various variable
  //
  Status = NetLibGetMacAddress (Private->Controller, &MacAddress, &HwAddressSize);
  ASSERT (Status == EFI_SUCCESS);
  VlanId = NetLibGetVlanId (Private->Controller);
  IScsiMacAddrToStr (&MacAddress, (UINT32) HwAddressSize, VlanId, MacString);

  //
  // Get the normal configuration.
  //
  BufferSize = sizeof (Session->ConfigData.NvData);
  Status = gRT->GetVariable (
                  MacString,
                  &gEfiIScsiInitiatorNameProtocolGuid,
                  NULL,
                  &BufferSize,
                  &Session->ConfigData.NvData
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  if (!Session->ConfigData.NvData.Enabled) {
    return EFI_ABORTED;
  }
  //
  // Get the CHAP Auth information.
  //
  BufferSize = sizeof (Session->AuthData.AuthConfig);
  Status = gRT->GetVariable (
                  MacString,
                  &gIScsiCHAPAuthInfoGuid,
                  NULL,
                  &BufferSize,
                  &Session->AuthData.AuthConfig
                  );

  if (!EFI_ERROR (Status) && Session->ConfigData.NvData.InitiatorInfoFromDhcp) {
    //
    // Start dhcp.
    //
    Status = IScsiDoDhcp (Private->Image, Private->Controller, &Session->ConfigData);
  }

  return Status;
}

/**
  Get the device path of the iSCSI tcp connection and update it.

  @param[in]  Private The iSCSI driver data.

  @return The updated device path.
  @retval NULL Other errors as indicated.
**/
EFI_DEVICE_PATH_PROTOCOL *
IScsiGetTcpConnDevicePath (
  IN ISCSI_DRIVER_DATA  *Private
  )
{
  ISCSI_SESSION             *Session;
  ISCSI_CONNECTION          *Conn;
  TCP4_IO                   *Tcp4Io;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_STATUS                Status;
  EFI_DEV_PATH              *DPathNode;

  Session = &Private->Session;
  if (Session->State != SESSION_STATE_LOGGED_IN) {
    return NULL;
  }

  Conn = NET_LIST_USER_STRUCT_S (
          Session->Conns.ForwardLink,
          ISCSI_CONNECTION,
          Link,
          ISCSI_CONNECTION_SIGNATURE
          );
  Tcp4Io = &Conn->Tcp4Io;

  Status = gBS->HandleProtocol (
                  Tcp4Io->Handle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID **)&DevicePath
                  );
  if (EFI_ERROR (Status)) {
    return NULL;
  }
  //
  // Duplicate it.
  //
  DevicePath  = DuplicateDevicePath (DevicePath);
  if (DevicePath == NULL) {
    return NULL;
  }

  DPathNode   = (EFI_DEV_PATH *) DevicePath;

  while (!IsDevicePathEnd (&DPathNode->DevPath)) {
    if ((DevicePathType (&DPathNode->DevPath) == MESSAGING_DEVICE_PATH) &&
        (DevicePathSubType (&DPathNode->DevPath) == MSG_IPv4_DP)
        ) {

      DPathNode->Ipv4.LocalPort       = 0;
      DPathNode->Ipv4.StaticIpAddress =
        (BOOLEAN) (!Session->ConfigData.NvData.InitiatorInfoFromDhcp);

      //
      //  Add a judgement here to support previous versions of IPv4_DEVICE_PATH.
      //  In previous versions of IPv4_DEVICE_PATH, GatewayIpAddress and SubnetMask
      //  do not exist.
      //  In new version of IPv4_DEVICE_PATH, structcure length is 27.
      //
      if (DevicePathNodeLength (&DPathNode->Ipv4) == IP4_NODE_LEN_NEW_VERSIONS) {

        IP4_COPY_ADDRESS (
          &DPathNode->Ipv4.GatewayIpAddress,
          &Session->ConfigData.NvData.Gateway
          );

        IP4_COPY_ADDRESS (
          &DPathNode->Ipv4.SubnetMask,
          &Session->ConfigData.NvData.SubnetMask
          );
      }

      break;
    }

    DPathNode = (EFI_DEV_PATH *) NextDevicePathNode (&DPathNode->DevPath);
  }

  return DevicePath;
}

/**
  Abort the session when the transition from BS to RT is initiated.

  @param[in]   Event  The event signaled.
  @param[in]  Context The iSCSI driver data.
**/
VOID
EFIAPI
IScsiOnExitBootService (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  ISCSI_DRIVER_DATA *Private;

  Private = (ISCSI_DRIVER_DATA *) Context;
  gBS->CloseEvent (Private->ExitBootServiceEvent);

  IScsiSessionAbort (&Private->Session);
}

/**
  Tests whether a controller handle is being managed by IScsi driver.

  This function tests whether the driver specified by DriverBindingHandle is
  currently managing the controller specified by ControllerHandle.  This test
  is performed by evaluating if the the protocol specified by ProtocolGuid is
  present on ControllerHandle and is was opened by DriverBindingHandle and Nic
  Device handle with an attribute of EFI_OPEN_PROTOCOL_BY_DRIVER.
  If ProtocolGuid is NULL, then ASSERT().

  @param  ControllerHandle     A handle for a controller to test.
  @param  DriverBindingHandle  Specifies the driver binding handle for the
                               driver.
  @param  ProtocolGuid         Specifies the protocol that the driver specified
                               by DriverBindingHandle opens in its Start()
                               function.

  @retval EFI_SUCCESS          ControllerHandle is managed by the driver
                               specified by DriverBindingHandle.
  @retval EFI_UNSUPPORTED      ControllerHandle is not managed by the driver
                               specified by DriverBindingHandle.

**/
EFI_STATUS
EFIAPI
IScsiTestManagedDevice (
  IN  EFI_HANDLE       ControllerHandle,
  IN  EFI_HANDLE       DriverBindingHandle,
  IN  EFI_GUID         *ProtocolGuid
  )
{
  EFI_STATUS     Status;
  VOID           *ManagedInterface;
  EFI_HANDLE     NicControllerHandle;

  ASSERT (ProtocolGuid != NULL);

  NicControllerHandle = NetLibGetNicHandle (ControllerHandle, ProtocolGuid);
  if (NicControllerHandle == NULL) {
    return EFI_UNSUPPORTED;
  }

  Status = gBS->OpenProtocol (
                  ControllerHandle,
                  (EFI_GUID *) ProtocolGuid,
                  &ManagedInterface,
                  DriverBindingHandle,
                  NicControllerHandle,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (!EFI_ERROR (Status)) {
    gBS->CloseProtocol (
           ControllerHandle,
           (EFI_GUID *) ProtocolGuid,
           DriverBindingHandle,
           NicControllerHandle
           );
    return EFI_UNSUPPORTED;
  }

  if (Status != EFI_ALREADY_STARTED) {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}