[mirror_edk2.git] / NetworkPkg / Dhcp6Dxe / Dhcp6Driver.c

/** @file\r
  Driver Binding functions and Service Binding functions\r
  implementation for Dhcp6 Driver.\r
\r
  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "Dhcp6Impl.h"\r
\r
EFI_DRIVER_BINDING_PROTOCOL  gDhcp6DriverBinding = {\r
  Dhcp6DriverBindingSupported,\r
  Dhcp6DriverBindingStart,\r
  Dhcp6DriverBindingStop,\r
  0xa,\r
  NULL,\r
  NULL\r
};\r
\r
EFI_SERVICE_BINDING_PROTOCOL  gDhcp6ServiceBindingTemplate = {\r
  Dhcp6ServiceBindingCreateChild,\r
  Dhcp6ServiceBindingDestroyChild\r
};\r
\r
/**\r
  Configure the default Udp6Io to receive all the DHCP6 traffic\r
  on this network interface.\r
\r
  @param[in]  UdpIo                  The pointer to Udp6Io to be configured.\r
  @param[in]  Context                The pointer to the context.\r
\r
  @retval EFI_SUCCESS            The Udp6Io is successfully configured.\r
  @retval Others                 Failed to configure the Udp6Io.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6ConfigureUdpIo (\r
  IN UDP_IO  *UdpIo,\r
  IN VOID    *Context\r
  )\r
{\r
  EFI_UDP6_PROTOCOL     *Udp6;\r
  EFI_UDP6_CONFIG_DATA  *Config;\r
\r
  Udp6   = UdpIo->Protocol.Udp6;\r
  Config = &(UdpIo->Config.Udp6);\r
\r
  ZeroMem (Config, sizeof (EFI_UDP6_CONFIG_DATA));\r
\r
  //\r
  // Set Udp6 configure data for the Dhcp6 instance.\r
  //\r
  Config->AcceptPromiscuous  = FALSE;\r
  Config->AcceptAnyPort      = FALSE;\r
  Config->AllowDuplicatePort = FALSE;\r
  Config->TrafficClass       = 0;\r
  Config->HopLimit           = 128;\r
  Config->ReceiveTimeout     = 0;\r
  Config->TransmitTimeout    = 0;\r
\r
  //\r
  // Configure an endpoint of client(0, 546), server(0, 0), the addresses\r
  // will be overridden later. Note that we MUST not limit RemotePort.\r
  // More details, refer to RFC 3315 section 5.2.\r
  //\r
  Config->StationPort = DHCP6_PORT_CLIENT;\r
  Config->RemotePort  = 0;\r
\r
  return Udp6->Configure (Udp6, Config);\r
}\r
\r
/**\r
  Destroy the Dhcp6 service. The Dhcp6 service may be partly initialized,\r
  or partly destroyed. If a resource is destroyed, it is marked as such in\r
  case the destroy failed and being called again later.\r
\r
  @param[in, out]  Service       The pointer to Dhcp6 service to be destroyed.\r
\r
**/\r
VOID\r
Dhcp6DestroyService (\r
  IN OUT DHCP6_SERVICE  *Service\r
  )\r
{\r
  //\r
  // All children instances should have been already destroyed here.\r
  //\r
  ASSERT (Service->NumOfChild == 0);\r
\r
  if (Service->ClientId != NULL) {\r
    FreePool (Service->ClientId);\r
  }\r
\r
  if (Service->UdpIo != NULL) {\r
    UdpIoFreeIo (Service->UdpIo);\r
  }\r
\r
  FreePool (Service);\r
}\r
\r
/**\r
  Create a new Dhcp6 service for the Nic controller.\r
\r
  @param[in]  Controller             The controller to be installed DHCP6 service\r
                                     binding protocol.\r
  @param[in]  ImageHandle            The image handle of the Dhcp6 driver.\r
  @param[out] Service                The return pointer of the new Dhcp6 service.\r
\r
  @retval EFI_SUCCESS            The Dhcp6 service is created successfully.\r
  @retval EFI_DEVICE_ERROR       An unexpected system or network error occurred.\r
  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resource.\r
\r
**/\r
EFI_STATUS\r
Dhcp6CreateService (\r
  IN  EFI_HANDLE     Controller,\r
  IN  EFI_HANDLE     ImageHandle,\r
  OUT DHCP6_SERVICE  **Service\r
  )\r
{\r
  DHCP6_SERVICE  *Dhcp6Srv;\r
  EFI_STATUS     Status;\r
\r
  *Service = NULL;\r
  Dhcp6Srv = AllocateZeroPool (sizeof (DHCP6_SERVICE));\r
\r
  if (Dhcp6Srv == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  //\r
  // Open the SNP protocol to get mode data later.\r
  //\r
  Dhcp6Srv->Snp = NULL;\r
  NetLibGetSnpHandle (Controller, &Dhcp6Srv->Snp);\r
  if (Dhcp6Srv->Snp == NULL) {\r
    FreePool (Dhcp6Srv);\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  //\r
  // Initialize the fields of the new Dhcp6 service.\r
  //\r
  Dhcp6Srv->Signature  = DHCP6_SERVICE_SIGNATURE;\r
  Dhcp6Srv->Controller = Controller;\r
  Dhcp6Srv->Image      = ImageHandle;\r
  Dhcp6Srv->Xid        = (0xffffff & NET_RANDOM (NetRandomInitSeed ()));\r
\r
  CopyMem (\r
    &Dhcp6Srv->ServiceBinding,\r
    &gDhcp6ServiceBindingTemplate,\r
    sizeof (EFI_SERVICE_BINDING_PROTOCOL)\r
    );\r
\r
  //\r
  // Locate Ip6->Ip6Config and store it for get IP6 Duplicate Address Detection transmits.\r
  //\r
  Status = gBS->HandleProtocol (\r
                  Controller,\r
                  &gEfiIp6ConfigProtocolGuid,\r
                  (VOID **)&Dhcp6Srv->Ip6Cfg\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    FreePool (Dhcp6Srv);\r
    return Status;\r
  }\r
\r
  //\r
  // Generate client Duid: If SMBIOS system UUID is located, generate DUID in DUID-UUID format.\r
  // Otherwise, in DUID-LLT format.\r
  //\r
  Dhcp6Srv->ClientId = Dhcp6GenerateClientId (Dhcp6Srv->Snp->Mode);\r
\r
  if (Dhcp6Srv->ClientId == NULL) {\r
    FreePool (Dhcp6Srv);\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  //\r
  // Create an Udp6Io for stateful transmit/receive of each Dhcp6 instance.\r
  //\r
  Dhcp6Srv->UdpIo = UdpIoCreateIo (\r
                      Controller,\r
                      ImageHandle,\r
                      Dhcp6ConfigureUdpIo,\r
                      UDP_IO_UDP6_VERSION,\r
                      NULL\r
                      );\r
\r
  if (Dhcp6Srv->UdpIo == NULL) {\r
    FreePool (Dhcp6Srv->ClientId);\r
    FreePool (Dhcp6Srv);\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  InitializeListHead (&Dhcp6Srv->Child);\r
\r
  *Service = Dhcp6Srv;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Destroy the Dhcp6 instance and recycle the resources.\r
\r
  @param[in, out]  Instance        The pointer to the Dhcp6 instance.\r
\r
**/\r
VOID\r
Dhcp6DestroyInstance (\r
  IN OUT DHCP6_INSTANCE  *Instance\r
  )\r
{\r
  //\r
  // Clean up the retry list first.\r
  //\r
  Dhcp6CleanupRetry (Instance, DHCP6_PACKET_ALL);\r
  gBS->CloseEvent (Instance->Timer);\r
\r
  //\r
  // Clean up the current configure data.\r
  //\r
  if (Instance->Config != NULL) {\r
    Dhcp6CleanupConfigData (Instance->Config);\r
    FreePool (Instance->Config);\r
  }\r
\r
  //\r
  // Clean up the current Ia.\r
  //\r
  if (Instance->IaCb.Ia != NULL) {\r
    if (Instance->IaCb.Ia->ReplyPacket != NULL) {\r
      FreePool (Instance->IaCb.Ia->ReplyPacket);\r
    }\r
\r
    FreePool (Instance->IaCb.Ia);\r
  }\r
\r
  if (Instance->Unicast != NULL) {\r
    FreePool (Instance->Unicast);\r
  }\r
\r
  if (Instance->AdSelect != NULL) {\r
    FreePool (Instance->AdSelect);\r
  }\r
\r
  FreePool (Instance);\r
}\r
\r
/**\r
  Create the Dhcp6 instance and initialize it.\r
\r
  @param[in]  Service              The pointer to the Dhcp6 service.\r
  @param[out] Instance             The pointer to the Dhcp6 instance.\r
\r
  @retval EFI_SUCCESS            The Dhcp6 instance is created.\r
  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resources.\r
\r
**/\r
EFI_STATUS\r
Dhcp6CreateInstance (\r
  IN  DHCP6_SERVICE   *Service,\r
  OUT DHCP6_INSTANCE  **Instance\r
  )\r
{\r
  EFI_STATUS      Status;\r
  DHCP6_INSTANCE  *Dhcp6Ins;\r
\r
  *Instance = NULL;\r
  Dhcp6Ins  = AllocateZeroPool (sizeof (DHCP6_INSTANCE));\r
\r
  if (Dhcp6Ins == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  //\r
  // Initialize the fields of the new Dhcp6 instance.\r
  //\r
  Dhcp6Ins->Signature    = DHCP6_INSTANCE_SIGNATURE;\r
  Dhcp6Ins->UdpSts       = EFI_ALREADY_STARTED;\r
  Dhcp6Ins->Service      = Service;\r
  Dhcp6Ins->InDestroy    = FALSE;\r
  Dhcp6Ins->MediaPresent = TRUE;\r
\r
  CopyMem (\r
    &Dhcp6Ins->Dhcp6,\r
    &gDhcp6ProtocolTemplate,\r
    sizeof (EFI_DHCP6_PROTOCOL)\r
    );\r
\r
  InitializeListHead (&Dhcp6Ins->TxList);\r
  InitializeListHead (&Dhcp6Ins->InfList);\r
\r
  //\r
  // There is a timer for each Dhcp6 instance, which is used to track the\r
  // lease time of Ia and the retransmission time of all sent packets.\r
  //\r
  Status = gBS->CreateEvent (\r
                  EVT_NOTIFY_SIGNAL | EVT_TIMER,\r
                  TPL_CALLBACK,\r
                  Dhcp6OnTimerTick,\r
                  Dhcp6Ins,\r
                  &Dhcp6Ins->Timer\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    FreePool (Dhcp6Ins);\r
    return Status;\r
  }\r
\r
  *Instance = Dhcp6Ins;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Callback function which provided by user to remove one node in NetDestroyLinkList process.\r
\r
  @param[in]    Entry           The entry to be removed.\r
  @param[in]    Context         Pointer to the callback context corresponds to the Context in NetDestroyLinkList.\r
\r
  @retval EFI_SUCCESS           The entry has been removed successfully.\r
  @retval Others                Fail to remove the entry.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6DestroyChildEntry (\r
  IN LIST_ENTRY  *Entry,\r
  IN VOID        *Context\r
  )\r
{\r
  DHCP6_INSTANCE                *Instance;\r
  EFI_SERVICE_BINDING_PROTOCOL  *ServiceBinding;\r
\r
  if ((Entry == NULL) || (Context == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Instance       = NET_LIST_USER_STRUCT_S (Entry, DHCP6_INSTANCE, Link, DHCP6_INSTANCE_SIGNATURE);\r
  ServiceBinding = (EFI_SERVICE_BINDING_PROTOCOL *)Context;\r
\r
  return ServiceBinding->DestroyChild (ServiceBinding, Instance->Handle);\r
}\r
\r
/**\r
  Entry point of the DHCP6 driver to install various protocols.\r
\r
  @param[in]  ImageHandle           The handle of the UEFI image file.\r
  @param[in]  SystemTable           The pointer to the EFI System Table.\r
\r
  @retval EFI_SUCCESS           The operation completed successfully.\r
  @retval Others                Unexpected error occurs.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6DriverEntryPoint (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  return EfiLibInstallDriverBindingComponentName2 (\r
           ImageHandle,\r
           SystemTable,\r
           &gDhcp6DriverBinding,\r
           ImageHandle,\r
           &gDhcp6ComponentName,\r
           &gDhcp6ComponentName2\r
           );\r
}\r
\r
/**\r
  Test to see if this driver supports ControllerHandle. This service\r
  is called by the EFI boot service ConnectController(). In\r
  order to make drivers as small as possible, there are a few calling\r
  restrictions for this service. ConnectController() must\r
  follow these calling restrictions. If any other agent wishes to call\r
  Supported() it must also follow these calling restrictions.\r
\r
  @param[in]  This                The pointer to the driver binding protocol.\r
  @param[in]  ControllerHandle    The handle of device to be tested.\r
  @param[in]  RemainingDevicePath Optional parameter use to pick a specific child\r
                                  device to be started.\r
\r
  @retval EFI_SUCCESS         This driver supports this device.\r
  @retval Others              This driver does not support this device.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6DriverBindingSupported (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  return gBS->OpenProtocol (\r
                ControllerHandle,\r
                &gEfiUdp6ServiceBindingProtocolGuid,\r
                NULL,\r
                This->DriverBindingHandle,\r
                ControllerHandle,\r
                EFI_OPEN_PROTOCOL_TEST_PROTOCOL\r
                );\r
}\r
\r
/**\r
  Start this driver on ControllerHandle. This service is called by the\r
  EFI boot service ConnectController(). In order to make\r
  drivers as small as possible, there are a few calling restrictions for\r
  this service. ConnectController() must follow these\r
  calling restrictions. If any other agent wishes to call Start() it\r
  must also follow these calling restrictions.\r
\r
  @param[in]  This                 The pointer to the driver binding protocol.\r
  @param[in]  ControllerHandle     The handle of device to be started.\r
  @param[in]  RemainingDevicePath  Optional parameter use to pick a specific child\r
                                   device to be started.\r
\r
  @retval EFI_SUCCESS          This driver is installed to ControllerHandle.\r
  @retval EFI_ALREADY_STARTED  This driver is already running on ControllerHandle.\r
  @retval other                This driver does not support this device.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6DriverBindingStart (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  EFI_STATUS     Status;\r
  DHCP6_SERVICE  *Service;\r
\r
  //\r
  // Check the Dhcp6 service whether already started.\r
  //\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  &gEfiDhcp6ServiceBindingProtocolGuid,\r
                  NULL,\r
                  This->DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_TEST_PROTOCOL\r
                  );\r
\r
  if (!EFI_ERROR (Status)) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  //\r
  // Create and initialize the Dhcp6 service.\r
  //\r
  Status = Dhcp6CreateService (\r
             ControllerHandle,\r
             This->DriverBindingHandle,\r
             &Service\r
             );\r
\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  ASSERT (Service != NULL);\r
\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &ControllerHandle,\r
                  &gEfiDhcp6ServiceBindingProtocolGuid,\r
                  &Service->ServiceBinding,\r
                  NULL\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    Dhcp6DestroyService (Service);\r
    return Status;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Stop this driver on ControllerHandle. This service is called by the\r
  EFI boot service DisconnectController(). In order to\r
  make drivers as small as possible, there are a few calling\r
  restrictions for this service. DisconnectController()\r
  must follow these calling restrictions. If any other agent wishes\r
  to call Stop() it must also follow these calling restrictions.\r
\r
  @param[in]  This              Protocol instance pointer.\r
  @param[in]  ControllerHandle  Handle of device to stop driver on\r
  @param[in]  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of\r
                                children is zero stop the entire bus driver.\r
  @param[in]  ChildHandleBuffer List of Child Handles to Stop.\r
\r
  @retval EFI_SUCCESS           This driver is removed ControllerHandle\r
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.\r
  @retval other                 This driver was not removed from this device\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6DriverBindingStop (\r
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN  EFI_HANDLE                   ControllerHandle,\r
  IN  UINTN                        NumberOfChildren,\r
  IN  EFI_HANDLE                   *ChildHandleBuffer   OPTIONAL\r
  )\r
{\r
  EFI_STATUS                    Status;\r
  EFI_HANDLE                    NicHandle;\r
  EFI_SERVICE_BINDING_PROTOCOL  *ServiceBinding;\r
  DHCP6_SERVICE                 *Service;\r
  LIST_ENTRY                    *List;\r
  UINTN                         ListLength;\r
\r
  //\r
  // Find and check the Nic handle by the controller handle.\r
  //\r
  NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiUdp6ProtocolGuid);\r
\r
  if (NicHandle == NULL) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  Status = gBS->OpenProtocol (\r
                  NicHandle,\r
                  &gEfiDhcp6ServiceBindingProtocolGuid,\r
                  (VOID **)&ServiceBinding,\r
                  This->DriverBindingHandle,\r
                  NicHandle,\r
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Service = DHCP6_SERVICE_FROM_THIS (ServiceBinding);\r
  if (!IsListEmpty (&Service->Child)) {\r
    //\r
    // Destroy all the children instances before destroy the service.\r
    //\r
    List   = &Service->Child;\r
    Status = NetDestroyLinkList (\r
               List,\r
               Dhcp6DestroyChildEntry,\r
               ServiceBinding,\r
               &ListLength\r
               );\r
    if (EFI_ERROR (Status) || (ListLength != 0)) {\r
      Status = EFI_DEVICE_ERROR;\r
    }\r
  }\r
\r
  if ((NumberOfChildren == 0) && !IsListEmpty (&Service->Child)) {\r
    Status = EFI_DEVICE_ERROR;\r
  }\r
\r
  if ((NumberOfChildren == 0) && IsListEmpty (&Service->Child)) {\r
    //\r
    // Destroy the service itself if no child instance left.\r
    //\r
    Status = gBS->UninstallProtocolInterface (\r
                    NicHandle,\r
                    &gEfiDhcp6ServiceBindingProtocolGuid,\r
                    ServiceBinding\r
                    );\r
    if (EFI_ERROR (Status)) {\r
      goto ON_EXIT;\r
    }\r
\r
    Dhcp6DestroyService (Service);\r
    Status = EFI_SUCCESS;\r
  }\r
\r
ON_EXIT:\r
  return Status;\r
}\r
\r
/**\r
  Creates a child handle and installs a protocol.\r
\r
  The CreateChild() function installs a protocol on ChildHandle.\r
  If ChildHandle is a pointer to NULL, then a new handle is created and returned in ChildHandle.\r
  If ChildHandle is not a pointer to NULL, then the protocol installs on the existing ChildHandle.\r
\r
  @param[in]      This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.\r
  @param[in, out] ChildHandle Pointer to the handle of the child to create. If it is NULL,\r
                              then a new handle is created. If it is a pointer to an existing\r
                              UEFI handle, then the protocol is added to the existing UEFI handle.\r
\r
  @retval EFI_SUCCESS           The protocol was added to ChildHandle.\r
  @retval EFI_INVALID_PARAMETER ChildHandle is NULL.\r
  @retval other                 The child handle was not created.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6ServiceBindingCreateChild (\r
  IN     EFI_SERVICE_BINDING_PROTOCOL  *This,\r
  IN OUT EFI_HANDLE                    *ChildHandle\r
  )\r
{\r
  EFI_STATUS      Status;\r
  EFI_TPL         OldTpl;\r
  DHCP6_SERVICE   *Service;\r
  DHCP6_INSTANCE  *Instance;\r
  VOID            *Udp6;\r
\r
  if ((This == NULL) || (ChildHandle == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Service = DHCP6_SERVICE_FROM_THIS (This);\r
\r
  Status = Dhcp6CreateInstance (Service, &Instance);\r
\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  ASSERT (Instance != NULL);\r
\r
  //\r
  // Start the timer when the instance is ready to use.\r
  //\r
  Status = gBS->SetTimer (\r
                  Instance->Timer,\r
                  TimerPeriodic,\r
                  TICKS_PER_SECOND\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    goto ON_ERROR;\r
  }\r
\r
  //\r
  // Install the DHCP6 protocol onto ChildHandle.\r
  //\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  ChildHandle,\r
                  &gEfiDhcp6ProtocolGuid,\r
                  &Instance->Dhcp6,\r
                  NULL\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    goto ON_ERROR;\r
  }\r
\r
  Instance->Handle = *ChildHandle;\r
\r
  //\r
  // Open the UDP6 protocol BY_CHILD.\r
  //\r
  Status = gBS->OpenProtocol (\r
                  Service->UdpIo->UdpHandle,\r
                  &gEfiUdp6ProtocolGuid,\r
                  (VOID **)&Udp6,\r
                  gDhcp6DriverBinding.DriverBindingHandle,\r
                  Instance->Handle,\r
                  EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    gBS->UninstallMultipleProtocolInterfaces (\r
           Instance->Handle,\r
           &gEfiDhcp6ProtocolGuid,\r
           &Instance->Dhcp6,\r
           NULL\r
           );\r
    goto ON_ERROR;\r
  }\r
\r
  //\r
  // Add into the children list of its parent service.\r
  //\r
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);\r
\r
  InsertTailList (&Service->Child, &Instance->Link);\r
  Service->NumOfChild++;\r
\r
  gBS->RestoreTPL (OldTpl);\r
  return EFI_SUCCESS;\r
\r
ON_ERROR:\r
\r
  Dhcp6DestroyInstance (Instance);\r
  return Status;\r
}\r
\r
/**\r
  Destroys a child handle with a protocol installed on it.\r
\r
  The DestroyChild() function does the opposite of CreateChild(). It removes a protocol\r
  that was installed by CreateChild() from ChildHandle. If the removed protocol is the\r
  last protocol on ChildHandle, then ChildHandle is destroyed.\r
\r
  @param[in]  This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.\r
  @param[in]  ChildHandle Handle of the child to destroy\r
\r
  @retval EFI_SUCCESS           The protocol was removed from ChildHandle.\r
  @retval EFI_UNSUPPORTED       ChildHandle does not support the protocol that is being removed.\r
  @retval EFI_INVALID_PARAMETER Child handle is NULL.\r
  @retval EFI_ACCESS_DENIED     The protocol could not be removed from the ChildHandle\r
                                because its services are being used.\r
  @retval other                 The child handle was not destroyed\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
Dhcp6ServiceBindingDestroyChild (\r
  IN EFI_SERVICE_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                    ChildHandle\r
  )\r
{\r
  EFI_STATUS          Status;\r
  EFI_TPL             OldTpl;\r
  EFI_DHCP6_PROTOCOL  *Dhcp6;\r
  DHCP6_SERVICE       *Service;\r
  DHCP6_INSTANCE      *Instance;\r
\r
  if ((This == NULL) || (ChildHandle == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Retrieve the private context data structures\r
  //\r
  Status = gBS->OpenProtocol (\r
                  ChildHandle,\r
                  &gEfiDhcp6ProtocolGuid,\r
                  (VOID **)&Dhcp6,\r
                  gDhcp6DriverBinding.DriverBindingHandle,\r
                  ChildHandle,\r
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  Instance = DHCP6_INSTANCE_FROM_THIS (Dhcp6);\r
  Service  = DHCP6_SERVICE_FROM_THIS (This);\r
\r
  if (Instance->Service != Service) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (Instance->InDestroy) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);\r
\r
  Instance->InDestroy = TRUE;\r
\r
  Status = gBS->CloseProtocol (\r
                  Service->UdpIo->UdpHandle,\r
                  &gEfiUdp6ProtocolGuid,\r
                  gDhcp6DriverBinding.DriverBindingHandle,\r
                  ChildHandle\r
                  );\r
\r
  if (EFI_ERROR (Status)) {\r
    Instance->InDestroy = FALSE;\r
    gBS->RestoreTPL (OldTpl);\r
    return Status;\r
  }\r
\r
  //\r
  // Uninstall the MTFTP6 protocol first to enable a top down destruction.\r
  //\r
  gBS->RestoreTPL (OldTpl);\r
  Status = gBS->UninstallProtocolInterface (\r
                  ChildHandle,\r
                  &gEfiDhcp6ProtocolGuid,\r
                  Dhcp6\r
                  );\r
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);\r
  if (EFI_ERROR (Status)) {\r
    Instance->InDestroy = FALSE;\r
    gBS->RestoreTPL (OldTpl);\r
    return Status;\r
  }\r
\r
  //\r
  // Remove it from the children list of its parent service.\r
  //\r
  RemoveEntryList (&Instance->Link);\r
  Service->NumOfChild--;\r
\r
  gBS->RestoreTPL (OldTpl);\r
\r
  Dhcp6DestroyInstance (Instance);\r
  return EFI_SUCCESS;\r
}\r