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      1 /** @file
      2   UEFI HTTP boot driver's private data structure and interfaces declaration.
      3 
      4 Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
      5 (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
      6 This program and the accompanying materials are licensed and made available under
      7 the terms and conditions of the BSD License that accompanies this distribution.
      8 The full text of the license may be found at
      9 http://opensource.org/licenses/bsd-license.php.
     10 
     11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     13 
     14 **/
     15 
     16 #ifndef __EFI_HTTP_BOOT_DXE_H__
     17 #define __EFI_HTTP_BOOT_DXE_H__
     18 
     19 #include <Uefi.h>
     20 
     21 #include <IndustryStandard/Http11.h>
     22 #include <IndustryStandard/Dhcp.h>
     23 
     24 //
     25 // Libraries
     26 //
     27 #include <Library/UefiBootServicesTableLib.h>
     28 #include <Library/UefiHiiServicesLib.h>
     29 #include <Library/UefiRuntimeServicesTableLib.h>
     30 #include <Library/MemoryAllocationLib.h>
     31 #include <Library/BaseLib.h>
     32 #include <Library/UefiLib.h>
     33 #include <Library/DevicePathLib.h>
     34 #include <Library/DebugLib.h>
     35 #include <Library/NetLib.h>
     36 #include <Library/HttpLib.h>
     37 #include <Library/HiiLib.h>
     38 #include <Library/PrintLib.h>
     39 
     40 //
     41 // UEFI Driver Model Protocols
     42 //
     43 #include <Protocol/DriverBinding.h>
     44 #include <Protocol/ComponentName2.h>
     45 #include <Protocol/ComponentName.h>
     46 
     47 //
     48 // Consumed Protocols
     49 //
     50 #include <Protocol/ServiceBinding.h>
     51 #include <Protocol/HiiConfigAccess.h>
     52 #include <Protocol/NetworkInterfaceIdentifier.h>
     53 #include <Protocol/Dhcp4.h>
     54 #include <Protocol/Dhcp6.h>
     55 #include <Protocol/Dns6.h>
     56 #include <Protocol/Http.h>
     57 #include <Protocol/Ip4Config2.h>
     58 #include <Protocol/Ip6Config.h>
     59 #include <Protocol/RamDisk.h>
     60 //
     61 // Produced Protocols
     62 //
     63 #include <Protocol/LoadFile.h>
     64 
     65 //
     66 // Consumed Guids
     67 //
     68 #include <Guid/HttpBootConfigHii.h>
     69 
     70 //
     71 // Driver Version
     72 //
     73 #define HTTP_BOOT_DXE_VERSION  0xa
     74 
     75 //
     76 // Provisional Standard Media Types defined in
     77 // http://www.iana.org/assignments/provisional-standard-media-types/provisional-standard-media-types.xhtml
     78 //
     79 #define HTTP_CONTENT_TYPE_APP_EFI           "application/efi"
     80 
     81 //
     82 // Protocol instances
     83 //
     84 extern EFI_DRIVER_BINDING_PROTOCOL  gHttpBootDxeDriverBinding;
     85 extern EFI_COMPONENT_NAME2_PROTOCOL gHttpBootDxeComponentName2;
     86 extern EFI_COMPONENT_NAME_PROTOCOL  gHttpBootDxeComponentName;
     87 
     88 //
     89 // Private data structure
     90 //
     91 typedef struct _HTTP_BOOT_PRIVATE_DATA      HTTP_BOOT_PRIVATE_DATA;
     92 typedef struct _HTTP_BOOT_VIRTUAL_NIC       HTTP_BOOT_VIRTUAL_NIC;
     93 
     94 typedef enum  {
     95   ImageTypeEfi,
     96   ImageTypeVirtualCd,
     97   ImageTypeVirtualDisk,
     98   ImageTypeMax
     99 } HTTP_BOOT_IMAGE_TYPE;
    100 
    101 //
    102 // Include files with internal function prototypes
    103 //
    104 #include "HttpBootComponentName.h"
    105 #include "HttpBootDhcp4.h"
    106 #include "HttpBootDhcp6.h"
    107 #include "HttpBootImpl.h"
    108 #include "HttpBootSupport.h"
    109 #include "HttpBootClient.h"
    110 #include "HttpBootConfig.h"
    111 
    112 typedef union {
    113   HTTP_BOOT_DHCP4_PACKET_CACHE              Dhcp4;
    114   HTTP_BOOT_DHCP6_PACKET_CACHE              Dhcp6;
    115 } HTTP_BOOT_DHCP_PACKET_CACHE;
    116 
    117 struct _HTTP_BOOT_VIRTUAL_NIC {
    118   UINT32                                    Signature;
    119   EFI_HANDLE                                Controller;
    120   EFI_HANDLE                                ImageHandle;
    121   EFI_LOAD_FILE_PROTOCOL                    LoadFile;
    122   EFI_DEVICE_PATH_PROTOCOL                  *DevicePath;
    123   HTTP_BOOT_PRIVATE_DATA                    *Private;
    124 };
    125 
    126 #define HTTP_BOOT_PRIVATE_DATA_FROM_CALLBACK_INFO(Callback) \
    127   CR ( \
    128   Callback, \
    129   HTTP_BOOT_PRIVATE_DATA, \
    130   CallbackInfo, \
    131   HTTP_BOOT_PRIVATE_DATA_SIGNATURE \
    132   )
    133 
    134 struct _HTTP_BOOT_PRIVATE_DATA {
    135   UINT32                                    Signature;
    136   EFI_HANDLE                                Controller;
    137 
    138   HTTP_BOOT_VIRTUAL_NIC                     *Ip4Nic;
    139   HTTP_BOOT_VIRTUAL_NIC                     *Ip6Nic;
    140 
    141   //
    142   // Cousumed children
    143   //
    144   EFI_HANDLE                                Ip6Child;
    145   EFI_HANDLE                                Dhcp4Child;
    146   EFI_HANDLE                                Dhcp6Child;
    147   HTTP_IO                                   HttpIo;
    148   BOOLEAN                                   HttpCreated;
    149 
    150   //
    151   // Consumed protocol
    152   //
    153   EFI_NETWORK_INTERFACE_IDENTIFIER_PROTOCOL *Nii;
    154   EFI_IP6_PROTOCOL                          *Ip6;
    155   EFI_IP4_CONFIG2_PROTOCOL                  *Ip4Config2;
    156   EFI_IP6_CONFIG_PROTOCOL                   *Ip6Config;
    157   EFI_DHCP4_PROTOCOL                        *Dhcp4;
    158   EFI_DHCP6_PROTOCOL                        *Dhcp6;
    159   EFI_DEVICE_PATH_PROTOCOL                  *ParentDevicePath;
    160 
    161 
    162   //
    163   // Produced protocol
    164   //
    165   EFI_LOAD_FILE_PROTOCOL                    LoadFile;
    166   EFI_DEVICE_PATH_PROTOCOL                  *DevicePath;
    167   UINT32                                    Id;
    168 
    169   //
    170   // HII callback info block
    171   //
    172   HTTP_BOOT_FORM_CALLBACK_INFO              CallbackInfo;
    173 
    174   //
    175   // Mode data
    176   //
    177   BOOLEAN                                   UsingIpv6;
    178   BOOLEAN                                   Started;
    179   EFI_IP_ADDRESS                            StationIp;
    180   EFI_IP_ADDRESS                            SubnetMask;
    181   EFI_IP_ADDRESS                            GatewayIp;
    182   EFI_IP_ADDRESS                            ServerIp;
    183   UINT16                                    Port;
    184 
    185   //
    186   // The URI string attempt to download through HTTP, may point to
    187   // the memory in cached DHCP offer, or to the memory in FilePathUri.
    188   //
    189   CHAR8                                     *BootFileUri;
    190   VOID                                      *BootFileUriParser;
    191   UINTN                                     BootFileSize;
    192   BOOLEAN                                   NoGateway;
    193   HTTP_BOOT_IMAGE_TYPE                      ImageType;
    194 
    195   //
    196   // URI string extracted from the input FilePath parameter.
    197   //
    198   CHAR8                                     *FilePathUri;
    199   VOID                                      *FilePathUriParser;
    200 
    201   //
    202   // Cached HTTP data
    203   //
    204   LIST_ENTRY                                CacheList;
    205 
    206   //
    207   // Cached DHCP offer
    208   //
    209   // OfferIndex records the index of DhcpOffer[] buffer, and OfferCount records the num of each type of offer.
    210   //
    211   // It supposed that
    212   //
    213   //   OfferNum:    8
    214   //   OfferBuffer: [ProxyNameUri, DhcpNameUri, DhcpIpUri, ProxyNameUri, ProxyIpUri, DhcpOnly, DhcpIpUri, DhcpNameUriDns]
    215   //   (OfferBuffer is 0-based.)
    216   //
    217   // And assume that (DhcpIpUri is the first priority actually.)
    218   //
    219   //   SelectIndex:     5
    220   //   SelectProxyType: HttpOfferTypeProxyIpUri
    221   //   (SelectIndex is 1-based, and 0 means no one is selected.)
    222   //
    223   // So it should be
    224   //
    225   //                 DhcpIpUri  DhcpNameUriDns  DhcpDns  DhcpOnly  ProxyNameUri  ProxyIpUri  DhcpNameUri
    226   //   OfferCount:  [       2,              1,       0,        1,            2,          1,            1]
    227   //
    228   //   OfferIndex: {[       2,              7,       0,        5,            0,         *4,            1]
    229   //                [       6,              0,       0,        0,            3,          0,            0]
    230   //                [       0,              0,       0,        0,            0,          0,            0]
    231   //                ...                                                                                 ]}
    232   //   (OfferIndex is 0-based.)
    233   //
    234   //
    235   UINT32                                    SelectIndex;
    236   UINT32                                    SelectProxyType;
    237   HTTP_BOOT_DHCP_PACKET_CACHE               OfferBuffer[HTTP_BOOT_OFFER_MAX_NUM];
    238   UINT32                                    OfferNum;
    239   UINT32                                    OfferCount[HttpOfferTypeMax];
    240   UINT32                                    OfferIndex[HttpOfferTypeMax][HTTP_BOOT_OFFER_MAX_NUM];
    241 };
    242 
    243 #define HTTP_BOOT_PRIVATE_DATA_SIGNATURE          SIGNATURE_32 ('H', 'B', 'P', 'D')
    244 #define HTTP_BOOT_VIRTUAL_NIC_SIGNATURE           SIGNATURE_32 ('H', 'B', 'V', 'N')
    245 #define HTTP_BOOT_PRIVATE_DATA_FROM_LOADFILE(a)   CR (a, HTTP_BOOT_PRIVATE_DATA, LoadFile, HTTP_BOOT_PRIVATE_DATA_SIGNATURE)
    246 #define HTTP_BOOT_PRIVATE_DATA_FROM_ID(a)         CR (a, HTTP_BOOT_PRIVATE_DATA, Id, HTTP_BOOT_PRIVATE_DATA_SIGNATURE)
    247 #define HTTP_BOOT_VIRTUAL_NIC_FROM_LOADFILE(a)    CR (a, HTTP_BOOT_VIRTUAL_NIC, LoadFile, HTTP_BOOT_VIRTUAL_NIC_SIGNATURE)
    248 extern EFI_LOAD_FILE_PROTOCOL               gHttpBootDxeLoadFile;
    249 
    250 /**
    251   Tests to see if this driver supports a given controller. If a child device is provided,
    252   it further tests to see if this driver supports creating a handle for the specified child device.
    253 
    254   This function checks to see if the driver specified by This supports the device specified by
    255   ControllerHandle. Drivers will typically use the device path attached to
    256   ControllerHandle and/or the services from the bus I/O abstraction attached to
    257   ControllerHandle to determine if the driver supports ControllerHandle. This function
    258   may be called many times during platform initialization. In order to reduce boot times, the tests
    259   performed by this function must be very small, and take as little time as possible to execute. This
    260   function must not change the state of any hardware devices, and this function must be aware that the
    261   device specified by ControllerHandle may already be managed by the same driver or a
    262   different driver. This function must match its calls to AllocatePages() with FreePages(),
    263   AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
    264   Because ControllerHandle may have been previously started by the same driver, if a protocol is
    265   already in the opened state, then it must not be closed with CloseProtocol(). This is required
    266   to guarantee the state of ControllerHandle is not modified by this function.
    267 
    268   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    269   @param[in]  ControllerHandle     The handle of the controller to test. This handle
    270                                    must support a protocol interface that supplies
    271                                    an I/O abstraction to the driver.
    272   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
    273                                    parameter is ignored by device drivers, and is optional for bus
    274                                    drivers. For bus drivers, if this parameter is not NULL, then
    275                                    the bus driver must determine if the bus controller specified
    276                                    by ControllerHandle and the child controller specified
    277                                    by RemainingDevicePath are both supported by this
    278                                    bus driver.
    279 
    280   @retval EFI_SUCCESS              The device specified by ControllerHandle and
    281                                    RemainingDevicePath is supported by the driver specified by This.
    282   @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
    283                                    RemainingDevicePath is already being managed by the driver
    284                                    specified by This.
    285   @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
    286                                    RemainingDevicePath is already being managed by a different
    287                                    driver or an application that requires exclusive access.
    288                                    Currently not implemented.
    289   @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
    290                                    RemainingDevicePath is not supported by the driver specified by This.
    291 **/
    292 EFI_STATUS
    293 EFIAPI
    294 HttpBootIp4DxeDriverBindingSupported (
    295   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    296   IN EFI_HANDLE                   ControllerHandle,
    297   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
    298   );
    299 
    300 /**
    301   Starts a device controller or a bus controller.
    302 
    303   The Start() function is designed to be invoked from the EFI boot service ConnectController().
    304   As a result, much of the error checking on the parameters to Start() has been moved into this
    305   common boot service. It is legal to call Start() from other locations,
    306   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
    307   1. ControllerHandle must be a valid EFI_HANDLE.
    308   2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
    309      EFI_DEVICE_PATH_PROTOCOL.
    310   3. Prior to calling Start(), the Supported() function for the driver specified by This must
    311      have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
    312 
    313   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    314   @param[in]  ControllerHandle     The handle of the controller to start. This handle
    315                                    must support a protocol interface that supplies
    316                                    an I/O abstraction to the driver.
    317   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
    318                                    parameter is ignored by device drivers, and is optional for bus
    319                                    drivers. For a bus driver, if this parameter is NULL, then handles
    320                                    for all the children of Controller are created by this driver.
    321                                    If this parameter is not NULL and the first Device Path Node is
    322                                    not the End of Device Path Node, then only the handle for the
    323                                    child device specified by the first Device Path Node of
    324                                    RemainingDevicePath is created by this driver.
    325                                    If the first Device Path Node of RemainingDevicePath is
    326                                    the End of Device Path Node, no child handle is created by this
    327                                    driver.
    328 
    329   @retval EFI_SUCCESS              The device was started.
    330   @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
    331   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
    332   @retval Others                   The driver failded to start the device.
    333 
    334 **/
    335 EFI_STATUS
    336 EFIAPI
    337 HttpBootIp4DxeDriverBindingStart (
    338   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    339   IN EFI_HANDLE                   ControllerHandle,
    340   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
    341   );
    342 
    343 /**
    344   Stops a device controller or a bus controller.
    345 
    346   The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
    347   As a result, much of the error checking on the parameters to Stop() has been moved
    348   into this common boot service. It is legal to call Stop() from other locations,
    349   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
    350   1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
    351      same driver's Start() function.
    352   2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
    353      EFI_HANDLE. In addition, all of these handles must have been created in this driver's
    354      Start() function, and the Start() function must have called OpenProtocol() on
    355      ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
    356 
    357   @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    358   @param[in]  ControllerHandle  A handle to the device being stopped. The handle must
    359                                 support a bus specific I/O protocol for the driver
    360                                 to use to stop the device.
    361   @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
    362   @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL
    363                                 if NumberOfChildren is 0.
    364 
    365   @retval EFI_SUCCESS           The device was stopped.
    366   @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.
    367 
    368 **/
    369 EFI_STATUS
    370 EFIAPI
    371 HttpBootIp4DxeDriverBindingStop (
    372   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    373   IN EFI_HANDLE                   ControllerHandle,
    374   IN UINTN                        NumberOfChildren,
    375   IN EFI_HANDLE                   *ChildHandleBuffer OPTIONAL
    376   );
    377 
    378 /**
    379   Tests to see if this driver supports a given controller. If a child device is provided,
    380   it further tests to see if this driver supports creating a handle for the specified child device.
    381 
    382   This function checks to see if the driver specified by This supports the device specified by
    383   ControllerHandle. Drivers will typically use the device path attached to
    384   ControllerHandle and/or the services from the bus I/O abstraction attached to
    385   ControllerHandle to determine if the driver supports ControllerHandle. This function
    386   may be called many times during platform initialization. In order to reduce boot times, the tests
    387   performed by this function must be very small, and take as little time as possible to execute. This
    388   function must not change the state of any hardware devices, and this function must be aware that the
    389   device specified by ControllerHandle may already be managed by the same driver or a
    390   different driver. This function must match its calls to AllocatePages() with FreePages(),
    391   AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
    392   Because ControllerHandle may have been previously started by the same driver, if a protocol is
    393   already in the opened state, then it must not be closed with CloseProtocol(). This is required
    394   to guarantee the state of ControllerHandle is not modified by this function.
    395 
    396   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    397   @param[in]  ControllerHandle     The handle of the controller to test. This handle
    398                                    must support a protocol interface that supplies
    399                                    an I/O abstraction to the driver.
    400   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
    401                                    parameter is ignored by device drivers, and is optional for bus
    402                                    drivers. For bus drivers, if this parameter is not NULL, then
    403                                    the bus driver must determine if the bus controller specified
    404                                    by ControllerHandle and the child controller specified
    405                                    by RemainingDevicePath are both supported by this
    406                                    bus driver.
    407 
    408   @retval EFI_SUCCESS              The device specified by ControllerHandle and
    409                                    RemainingDevicePath is supported by the driver specified by This.
    410   @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
    411                                    RemainingDevicePath is already being managed by the driver
    412                                    specified by This.
    413   @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
    414                                    RemainingDevicePath is already being managed by a different
    415                                    driver or an application that requires exclusive access.
    416                                    Currently not implemented.
    417   @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
    418                                    RemainingDevicePath is not supported by the driver specified by This.
    419 **/
    420 EFI_STATUS
    421 EFIAPI
    422 HttpBootIp6DxeDriverBindingSupported (
    423   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    424   IN EFI_HANDLE                   ControllerHandle,
    425   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
    426   );
    427 
    428 /**
    429   Starts a device controller or a bus controller.
    430 
    431   The Start() function is designed to be invoked from the EFI boot service ConnectController().
    432   As a result, much of the error checking on the parameters to Start() has been moved into this
    433   common boot service. It is legal to call Start() from other locations,
    434   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
    435   1. ControllerHandle must be a valid EFI_HANDLE.
    436   2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
    437      EFI_DEVICE_PATH_PROTOCOL.
    438   3. Prior to calling Start(), the Supported() function for the driver specified by This must
    439      have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
    440 
    441   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    442   @param[in]  ControllerHandle     The handle of the controller to start. This handle
    443                                    must support a protocol interface that supplies
    444                                    an I/O abstraction to the driver.
    445   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
    446                                    parameter is ignored by device drivers, and is optional for bus
    447                                    drivers. For a bus driver, if this parameter is NULL, then handles
    448                                    for all the children of Controller are created by this driver.
    449                                    If this parameter is not NULL and the first Device Path Node is
    450                                    not the End of Device Path Node, then only the handle for the
    451                                    child device specified by the first Device Path Node of
    452                                    RemainingDevicePath is created by this driver.
    453                                    If the first Device Path Node of RemainingDevicePath is
    454                                    the End of Device Path Node, no child handle is created by this
    455                                    driver.
    456 
    457   @retval EFI_SUCCESS              The device was started.
    458   @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
    459   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
    460   @retval Others                   The driver failded to start the device.
    461 
    462 **/
    463 EFI_STATUS
    464 EFIAPI
    465 HttpBootIp6DxeDriverBindingStart (
    466   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    467   IN EFI_HANDLE                   ControllerHandle,
    468   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
    469   );
    470 
    471 /**
    472   Stops a device controller or a bus controller.
    473 
    474   The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
    475   As a result, much of the error checking on the parameters to Stop() has been moved
    476   into this common boot service. It is legal to call Stop() from other locations,
    477   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
    478   1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
    479      same driver's Start() function.
    480   2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
    481      EFI_HANDLE. In addition, all of these handles must have been created in this driver's
    482      Start() function, and the Start() function must have called OpenProtocol() on
    483      ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
    484 
    485   @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
    486   @param[in]  ControllerHandle  A handle to the device being stopped. The handle must
    487                                 support a bus specific I/O protocol for the driver
    488                                 to use to stop the device.
    489   @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
    490   @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL
    491                                 if NumberOfChildren is 0.
    492 
    493   @retval EFI_SUCCESS           The device was stopped.
    494   @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.
    495 
    496 **/
    497 EFI_STATUS
    498 EFIAPI
    499 HttpBootIp6DxeDriverBindingStop (
    500   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    501   IN EFI_HANDLE                   ControllerHandle,
    502   IN UINTN                        NumberOfChildren,
    503   IN EFI_HANDLE                   *ChildHandleBuffer OPTIONAL
    504   );
    505 #endif
    506