MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Driver.c

   1 /** @file
   2
   3 Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 **/
  13
  14 #include "Dhcp4Impl.h"
  15 #include "Dhcp4Driver.h"
  16
  17 EFI_DRIVER_BINDING_PROTOCOL gDhcp4DriverBinding = {
  18   Dhcp4DriverBindingSupported,
  19   Dhcp4DriverBindingStart,
  20   Dhcp4DriverBindingStop,
  21   0xa,
  22   NULL,
  23   NULL
  24 };
  25
  26 EFI_SERVICE_BINDING_PROTOCOL mDhcp4ServiceBindingTemplate = {
  27   Dhcp4ServiceBindingCreateChild,
  28   Dhcp4ServiceBindingDestroyChild
  29 };
  30
  31 /**
  32   This is the declaration of an EFI image entry point. This entry point is
  33   the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
  34   both device drivers and bus drivers.
  35
  36   Entry point of the DHCP driver to install various protocols.
  37
  38   @param[in]  ImageHandle           The firmware allocated handle for the UEFI image.
  39   @param[in]  SystemTable           A pointer to the EFI System Table.
  40
  41   @retval EFI_SUCCESS           The operation completed successfully.
  42   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.
  43
  44 **/
  45 EFI_STATUS
  46 EFIAPI
  47 Dhcp4DriverEntryPoint (
  48   IN EFI_HANDLE             ImageHandle,
  49   IN EFI_SYSTEM_TABLE       *SystemTable
  50   )
  51 {
  52   return EfiLibInstallDriverBindingComponentName2 (
  53            ImageHandle,
  54            SystemTable,
  55            &gDhcp4DriverBinding,
  56            ImageHandle,
  57            &gDhcp4ComponentName,
  58            &gDhcp4ComponentName2
  59            );
  60 }
  61
  62
  63 /**
  64   Test to see if this driver supports ControllerHandle. This service
  65   is called by the EFI boot service ConnectController(). In
  66   order to make drivers as small as possible, there are a few calling
  67   restrictions for this service. ConnectController() must
  68   follow these calling restrictions. If any other agent wishes to call
  69   Supported() it must also follow these calling restrictions.
  70
  71   @param[in]  This                Protocol instance pointer.
  72   @param[in]  ControllerHandle    Handle of device to test
  73   @param[in]  RemainingDevicePath Optional parameter use to pick a specific child
  74                                   device to start.
  75
  76   @retval EFI_SUCCESS         This driver supports this device
  77   @retval EFI_ALREADY_STARTED This driver is already running on this device
  78   @retval other               This driver does not support this device
  79
  80 **/
  81 EFI_STATUS
  82 EFIAPI
  83 Dhcp4DriverBindingSupported (
  84   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  85   IN EFI_HANDLE                   ControllerHandle,
  86   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
  87   )
  88 {
  89   EFI_STATUS  Status;
  90
  91   Status = gBS->OpenProtocol (
  92                   ControllerHandle,
  93                   &gEfiUdp4ServiceBindingProtocolGuid,
  94                   NULL,
  95                   This->DriverBindingHandle,
  96                   ControllerHandle,
  97                   EFI_OPEN_PROTOCOL_TEST_PROTOCOL
  98                   );
  99
 100   return Status;
 101 }
 102
 103
 104
 105 /**
 106   Configure the default UDP child to receive all the DHCP traffics
 107   on this network interface.
 108
 109   @param[in]  UdpIo                  The UDP IO to configure
 110   @param[in]  Context                The context to the function
 111
 112   @retval EFI_SUCCESS            The UDP IO is successfully configured.
 113   @retval Others                 Failed to configure the UDP child.
 114
 115 **/
 116 EFI_STATUS
 117 EFIAPI
 118 DhcpConfigUdpIo (
 119   IN UDP_IO                 *UdpIo,
 120   IN VOID                   *Context
 121   )
 122 {
 123   EFI_UDP4_CONFIG_DATA      UdpConfigData;
 124
 125   UdpConfigData.AcceptBroadcast           = TRUE;
 126   UdpConfigData.AcceptPromiscuous         = FALSE;
 127   UdpConfigData.AcceptAnyPort             = FALSE;
 128   UdpConfigData.AllowDuplicatePort        = TRUE;
 129   UdpConfigData.TypeOfService             = 0;
 130   UdpConfigData.TimeToLive                = 64;
 131   UdpConfigData.DoNotFragment             = FALSE;
 132   UdpConfigData.ReceiveTimeout            = 0;
 133   UdpConfigData.TransmitTimeout           = 0;
 134
 135   UdpConfigData.UseDefaultAddress         = FALSE;
 136   UdpConfigData.StationPort               = DHCP_CLIENT_PORT;
 137   UdpConfigData.RemotePort                = DHCP_SERVER_PORT;
 138
 139   ZeroMem (&UdpConfigData.StationAddress, sizeof (EFI_IPv4_ADDRESS));
 140   ZeroMem (&UdpConfigData.SubnetMask, sizeof (EFI_IPv4_ADDRESS));
 141   ZeroMem (&UdpConfigData.RemoteAddress, sizeof (EFI_IPv4_ADDRESS));
 142
 143   return UdpIo->Protocol.Udp4->Configure (UdpIo->Protocol.Udp4, &UdpConfigData);;
 144 }
 145
 146
 147
 148 /**
 149   Destroy the DHCP service. The Dhcp4 service may be partly initialized,
 150   or partly destroyed. If a resource is destroyed, it is marked as so in
 151   case the destroy failed and being called again later.
 152
 153   @param[in]  DhcpSb                 The DHCP service instance to destroy.
 154
 155   @retval EFI_SUCCESS            Always return success.
 156
 157 **/
 158 EFI_STATUS
 159 Dhcp4CloseService (
 160   IN DHCP_SERVICE           *DhcpSb
 161   )
 162 {
 163   DhcpCleanLease (DhcpSb);
 164
 165   if (DhcpSb->UdpIo != NULL) {
 166     UdpIoFreeIo (DhcpSb->UdpIo);
 167     DhcpSb->UdpIo = NULL;
 168   }
 169
 170   if (DhcpSb->Timer != NULL) {
 171     gBS->SetTimer (DhcpSb->Timer, TimerCancel, 0);
 172     gBS->CloseEvent (DhcpSb->Timer);
 173
 174     DhcpSb->Timer = NULL;
 175   }
 176
 177   return EFI_SUCCESS;
 178 }
 179
 180
 181
 182 /**
 183   Create a new DHCP service binding instance for the controller.
 184
 185   @param[in]  Controller             The controller to install DHCP service binding
 186                                      protocol onto
 187   @param[in]  ImageHandle            The driver's image handle
 188   @param[out] Service                The variable to receive the created DHCP service
 189                                      instance.
 190
 191   @retval EFI_OUT_OF_RESOURCES   Failed to allocate resource .
 192   @retval EFI_SUCCESS            The DHCP service instance is created.
 193   @retval other                  Other error occurs.
 194
 195 **/
 196 EFI_STATUS
 197 Dhcp4CreateService (
 198   IN  EFI_HANDLE            Controller,
 199   IN  EFI_HANDLE            ImageHandle,
 200   OUT DHCP_SERVICE          **Service
 201   )
 202 {
 203   DHCP_SERVICE              *DhcpSb;
 204   EFI_STATUS                Status;
 205
 206   *Service  = NULL;
 207   DhcpSb    = AllocateZeroPool (sizeof (DHCP_SERVICE));
 208
 209   if (DhcpSb == NULL) {
 210     return EFI_OUT_OF_RESOURCES;
 211   }
 212
 213   DhcpSb->Signature       = DHCP_SERVICE_SIGNATURE;
 214   DhcpSb->ServiceState    = DHCP_UNCONFIGED;
 215   DhcpSb->Controller      = Controller;
 216   DhcpSb->Image           = ImageHandle;
 217   InitializeListHead (&DhcpSb->Children);
 218   DhcpSb->DhcpState       = Dhcp4Stopped;
 219   DhcpSb->Xid             = NET_RANDOM (NetRandomInitSeed ());
 220   CopyMem (
 221     &DhcpSb->ServiceBinding,
 222     &mDhcp4ServiceBindingTemplate,
 223     sizeof (EFI_SERVICE_BINDING_PROTOCOL)
 224     );
 225   //
 226   // Create various resources, UdpIo, Timer, and get Mac address
 227   //
 228   Status = gBS->CreateEvent (
 229                   EVT_NOTIFY_SIGNAL | EVT_TIMER,
 230                   TPL_CALLBACK,
 231                   DhcpOnTimerTick,
 232                   DhcpSb,
 233                   &DhcpSb->Timer
 234                   );
 235
 236   if (EFI_ERROR (Status)) {
 237     goto ON_ERROR;
 238   }
 239
 240   DhcpSb->UdpIo = UdpIoCreateIo (
 241                     Controller,
 242                     ImageHandle,
 243                     DhcpConfigUdpIo,
 244                     UDP_IO_UDP4_VERSION,
 245                     NULL
 246                     );
 247
 248   if (DhcpSb->UdpIo == NULL) {
 249     Status = EFI_OUT_OF_RESOURCES;
 250     goto ON_ERROR;
 251   }
 252
 253   DhcpSb->HwLen  = (UINT8) DhcpSb->UdpIo->SnpMode.HwAddressSize;
 254   DhcpSb->HwType = DhcpSb->UdpIo->SnpMode.IfType;
 255   CopyMem (&DhcpSb->Mac, &DhcpSb->UdpIo->SnpMode.CurrentAddress, sizeof (DhcpSb->Mac));
 256
 257   *Service       = DhcpSb;
 258   return EFI_SUCCESS;
 259
 260 ON_ERROR:
 261   Dhcp4CloseService (DhcpSb);
 262   FreePool (DhcpSb);
 263
 264   return Status;
 265 }
 266
 267
 268 /**
 269   Start this driver on ControllerHandle. This service is called by the
 270   EFI boot service ConnectController(). In order to make
 271   drivers as small as possible, there are a few calling restrictions for
 272   this service. ConnectController() must follow these
 273   calling restrictions. If any other agent wishes to call Start() it
 274   must also follow these calling restrictions.
 275
 276   @param[in]  This                 Protocol instance pointer.
 277   @param[in]  ControllerHandle     Handle of device to bind driver to
 278   @param[in]  RemainingDevicePath  Optional parameter use to pick a specific child
 279                                    device to start.
 280
 281   @retval EFI_SUCCESS          This driver is added to ControllerHandle
 282   @retval EFI_ALREADY_STARTED  This driver is already running on ControllerHandle
 283   @retval other                This driver does not support this device
 284
 285 **/
 286 EFI_STATUS
 287 EFIAPI
 288 Dhcp4DriverBindingStart (
 289   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 290   IN EFI_HANDLE                   ControllerHandle,
 291   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
 292   )
 293 {
 294   DHCP_SERVICE              *DhcpSb;
 295   EFI_STATUS                Status;
 296
 297   //
 298   // First: test for the DHCP4 Protocol
 299   //
 300   Status = gBS->OpenProtocol (
 301                   ControllerHandle,
 302                   &gEfiDhcp4ServiceBindingProtocolGuid,
 303                   NULL,
 304                   This->DriverBindingHandle,
 305                   ControllerHandle,
 306                   EFI_OPEN_PROTOCOL_TEST_PROTOCOL
 307                   );
 308
 309   if (Status == EFI_SUCCESS) {
 310     return EFI_ALREADY_STARTED;
 311   }
 312
 313   Status = Dhcp4CreateService (ControllerHandle, This->DriverBindingHandle, &DhcpSb);
 314
 315   if (EFI_ERROR (Status)) {
 316     return Status;
 317   }
 318   ASSERT (DhcpSb != NULL);
 319
 320   //
 321   // Start the receiving
 322   //
 323   Status = UdpIoRecvDatagram (DhcpSb->UdpIo, DhcpInput, DhcpSb, 0);
 324
 325   if (EFI_ERROR (Status)) {
 326     goto ON_ERROR;
 327   }
 328   Status = gBS->SetTimer (DhcpSb->Timer, TimerPeriodic, TICKS_PER_SECOND);
 329
 330   if (EFI_ERROR (Status)) {
 331     goto ON_ERROR;
 332   }
 333
 334   //
 335   // Install the Dhcp4ServiceBinding Protocol onto ControlerHandle
 336   //
 337   Status = gBS->InstallMultipleProtocolInterfaces (
 338                   &ControllerHandle,
 339                   &gEfiDhcp4ServiceBindingProtocolGuid,
 340                   &DhcpSb->ServiceBinding,
 341                   NULL
 342                   );
 343
 344   if (EFI_ERROR (Status)) {
 345     goto ON_ERROR;
 346   }
 347
 348   return Status;
 349
 350 ON_ERROR:
 351   Dhcp4CloseService (DhcpSb);
 352   FreePool (DhcpSb);
 353   return Status;
 354 }
 355
 356 /**
 357   Callback function which provided by user to remove one node in NetDestroyLinkList process.
 358
 359   @param[in]    Entry           The entry to be removed.
 360   @param[in]    Context         Pointer to the callback context corresponds to the Context in NetDestroyLinkList.
 361
 362   @retval EFI_SUCCESS           The entry has been removed successfully.
 363   @retval Others                Fail to remove the entry.
 364
 365 **/
 366 EFI_STATUS
 367 EFIAPI
 368 Dhcp4DestroyChildEntry (
 369   IN LIST_ENTRY         *Entry,
 370   IN VOID               *Context
 371   )
 372 {
 373   DHCP_PROTOCOL                    *Instance;
 374   EFI_SERVICE_BINDING_PROTOCOL     *ServiceBinding;
 375
 376   if (Entry == NULL || Context == NULL) {
 377     return EFI_INVALID_PARAMETER;
 378   }
 379
 380   Instance = NET_LIST_USER_STRUCT_S (Entry, DHCP_PROTOCOL, Link, DHCP_PROTOCOL_SIGNATURE);
 381   ServiceBinding = (EFI_SERVICE_BINDING_PROTOCOL *) Context;
 382
 383   return ServiceBinding->DestroyChild (ServiceBinding, Instance->Handle);
 384 }
 385
 386
 387 /**
 388   Stop this driver on ControllerHandle. This service is called by the
 389   EFI boot service DisconnectController(). In order to
 390   make drivers as small as possible, there are a few calling
 391   restrictions for this service. DisconnectController()
 392   must follow these calling restrictions. If any other agent wishes
 393   to call Stop() it must also follow these calling restrictions.
 394
 395   @param[in]  This              Protocol instance pointer.
 396   @param[in]  ControllerHandle  Handle of device to stop driver on
 397   @param[in]  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of
 398                                 children is zero stop the entire bus driver.
 399   @param[in]  ChildHandleBuffer List of Child Handles to Stop.
 400
 401   @retval EFI_SUCCESS       This driver is removed ControllerHandle
 402   @retval other             This driver was not removed from this device
 403
 404 **/
 405 EFI_STATUS
 406 EFIAPI
 407 Dhcp4DriverBindingStop (
 408   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
 409   IN  EFI_HANDLE                   ControllerHandle,
 410   IN  UINTN                        NumberOfChildren,
 411   IN  EFI_HANDLE                   *ChildHandleBuffer
 412   )
 413 {
 414   EFI_SERVICE_BINDING_PROTOCOL  *ServiceBinding;
 415   DHCP_SERVICE                  *DhcpSb;
 416   EFI_HANDLE                    NicHandle;
 417   EFI_STATUS                    Status;
 418   LIST_ENTRY                    *List;
 419   UINTN                         ListLength;
 420
 421   //
 422   // DHCP driver opens UDP child, So, the ControllerHandle is the
 423   // UDP child handle. locate the Nic handle first.
 424   //
 425   NicHandle = NetLibGetNicHandle (ControllerHandle, &gEfiUdp4ProtocolGuid);
 426
 427   if (NicHandle == NULL) {
 428     return EFI_SUCCESS;
 429   }
 430
 431    Status = gBS->OpenProtocol (
 432                   NicHandle,
 433                   &gEfiDhcp4ServiceBindingProtocolGuid,
 434                   (VOID **) &ServiceBinding,
 435                   This->DriverBindingHandle,
 436                   NicHandle,
 437                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
 438                   );
 439
 440   if (EFI_ERROR (Status)) {
 441     return EFI_DEVICE_ERROR;
 442   }
 443
 444   DhcpSb = DHCP_SERVICE_FROM_THIS (ServiceBinding);
 445   if (!IsListEmpty (&DhcpSb->Children)) {
 446     //
 447     // Destroy all the children instances before destory the service.
 448     //
 449     List = &DhcpSb->Children;
 450     Status = NetDestroyLinkList (
 451                List,
 452                Dhcp4DestroyChildEntry,
 453                ServiceBinding,
 454                &ListLength
 455                );
 456     if (EFI_ERROR (Status) || ListLength != 0) {
 457       Status = EFI_DEVICE_ERROR;
 458     }
 459   }
 460
 461   if (NumberOfChildren == 0 && !IsListEmpty (&DhcpSb->Children)) {
 462     Status = EFI_DEVICE_ERROR;
 463   }
 464
 465   if (NumberOfChildren == 0 && IsListEmpty (&DhcpSb->Children)) {
 466     //
 467     // Destroy the service itself if no child instance left.
 468     //
 469     DhcpSb->ServiceState = DHCP_DESTROY;
 470
 471     gBS->UninstallProtocolInterface (
 472            NicHandle,
 473            &gEfiDhcp4ServiceBindingProtocolGuid,
 474            ServiceBinding
 475            );
 476
 477     Dhcp4CloseService (DhcpSb);
 478
 479     if (gDhcpControllerNameTable != NULL) {
 480       FreeUnicodeStringTable (gDhcpControllerNameTable);
 481       gDhcpControllerNameTable = NULL;
 482     }
 483     FreePool (DhcpSb);
 484
 485     Status = EFI_SUCCESS;
 486   }
 487
 488   return Status;
 489 }
 490
 491
 492 /**
 493   Initialize a new DHCP instance.
 494
 495   @param  DhcpSb                 The dhcp service instance
 496   @param  Instance               The dhcp instance to initialize
 497
 498 **/
 499 VOID
 500 DhcpInitProtocol (
 501   IN     DHCP_SERVICE           *DhcpSb,
 502   IN OUT DHCP_PROTOCOL          *Instance
 503   )
 504 {
 505   Instance->Signature         = DHCP_PROTOCOL_SIGNATURE;
 506   CopyMem (&Instance->Dhcp4Protocol, &mDhcp4ProtocolTemplate, sizeof (Instance->Dhcp4Protocol));
 507   InitializeListHead (&Instance->Link);
 508   Instance->Handle            = NULL;
 509   Instance->Service           = DhcpSb;
 510   Instance->InDestroy         = FALSE;
 511   Instance->CompletionEvent   = NULL;
 512   Instance->RenewRebindEvent  = NULL;
 513   Instance->Token             = NULL;
 514   Instance->UdpIo             = NULL;
 515   Instance->ElaspedTime       = 0;
 516   NetbufQueInit (&Instance->ResponseQueue);
 517 }
 518
 519
 520 /**
 521   Creates a child handle and installs a protocol.
 522
 523   The CreateChild() function installs a protocol on ChildHandle.
 524   If ChildHandle is a pointer to NULL, then a new handle is created and returned in ChildHandle.
 525   If ChildHandle is not a pointer to NULL, then the protocol installs on the existing ChildHandle.
 526
 527   @param  This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.
 528   @param  ChildHandle Pointer to the handle of the child to create. If it is NULL,
 529                       then a new handle is created. If it is a pointer to an existing UEFI handle,
 530                       then the protocol is added to the existing UEFI handle.
 531
 532   @retval EFI_SUCCES            The protocol was added to ChildHandle.
 533   @retval EFI_INVALID_PARAMETER ChildHandle is NULL.
 534   @retval EFI_OUT_OF_RESOURCES  There are not enough resources available to create
 535                                 the child
 536   @retval other                 The child handle was not created
 537
 538 **/
 539 EFI_STATUS
 540 EFIAPI
 541 Dhcp4ServiceBindingCreateChild (
 542   IN EFI_SERVICE_BINDING_PROTOCOL  *This,
 543   IN EFI_HANDLE                    *ChildHandle
 544   )
 545 {
 546   DHCP_SERVICE              *DhcpSb;
 547   DHCP_PROTOCOL             *Instance;
 548   EFI_STATUS                Status;
 549   EFI_TPL                   OldTpl;
 550   VOID                      *Udp4;
 551
 552   if ((This == NULL) || (ChildHandle == NULL)) {
 553     return EFI_INVALID_PARAMETER;
 554   }
 555
 556   Instance = AllocatePool (sizeof (*Instance));
 557
 558   if (Instance == NULL) {
 559     return EFI_OUT_OF_RESOURCES;
 560   }
 561
 562   DhcpSb = DHCP_SERVICE_FROM_THIS (This);
 563   DhcpInitProtocol (DhcpSb, Instance);
 564
 565   //
 566   // Install DHCP4 onto ChildHandle
 567   //
 568   Status = gBS->InstallMultipleProtocolInterfaces (
 569                   ChildHandle,
 570                   &gEfiDhcp4ProtocolGuid,
 571                   &Instance->Dhcp4Protocol,
 572                   NULL
 573                   );
 574
 575   if (EFI_ERROR (Status)) {
 576     FreePool (Instance);
 577     return Status;
 578   }
 579
 580   Instance->Handle  = *ChildHandle;
 581
 582   //
 583   // Open the Udp4 protocol BY_CHILD.
 584   //
 585   Status = gBS->OpenProtocol (
 586                   DhcpSb->UdpIo->UdpHandle,
 587                   &gEfiUdp4ProtocolGuid,
 588                   (VOID **) &Udp4,
 589                   gDhcp4DriverBinding.DriverBindingHandle,
 590                   Instance->Handle,
 591                   EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
 592                   );
 593   if (EFI_ERROR (Status)) {
 594     gBS->UninstallMultipleProtocolInterfaces (
 595            Instance->Handle,
 596            &gEfiDhcp4ProtocolGuid,
 597            &Instance->Dhcp4Protocol,
 598            NULL
 599            );
 600
 601     FreePool (Instance);
 602     return Status;
 603   }
 604
 605   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
 606
 607   InsertTailList (&DhcpSb->Children, &Instance->Link);
 608   DhcpSb->NumChildren++;
 609
 610   gBS->RestoreTPL (OldTpl);
 611
 612   return EFI_SUCCESS;
 613 }
 614
 615
 616 /**
 617   Destroys a child handle with a protocol installed on it.
 618
 619   The DestroyChild() function does the opposite of CreateChild(). It removes a protocol
 620   that was installed by CreateChild() from ChildHandle. If the removed protocol is the
 621   last protocol on ChildHandle, then ChildHandle is destroyed.
 622
 623   @param  This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.
 624   @param  ChildHandle Handle of the child to destroy
 625
 626   @retval EFI_SUCCES            The protocol was removed from ChildHandle.
 627   @retval EFI_UNSUPPORTED       ChildHandle does not support the protocol that is being removed.
 628   @retval EFI_INVALID_PARAMETER Child handle is NULL.
 629   @retval EFI_ACCESS_DENIED     The protocol could not be removed from the ChildHandle
 630                                 because its services are being used.
 631   @retval other                 The child handle was not destroyed
 632
 633 **/
 634 EFI_STATUS
 635 EFIAPI
 636 Dhcp4ServiceBindingDestroyChild (
 637   IN EFI_SERVICE_BINDING_PROTOCOL  *This,
 638   IN EFI_HANDLE                    ChildHandle
 639   )
 640 {
 641   DHCP_SERVICE              *DhcpSb;
 642   DHCP_PROTOCOL             *Instance;
 643   EFI_DHCP4_PROTOCOL        *Dhcp;
 644   EFI_TPL                   OldTpl;
 645   EFI_STATUS                Status;
 646
 647   if ((This == NULL) || (ChildHandle == NULL)) {
 648     return EFI_INVALID_PARAMETER;
 649   }
 650
 651   //
 652   // Retrieve the private context data structures
 653   //
 654   Status = gBS->OpenProtocol (
 655                   ChildHandle,
 656                   &gEfiDhcp4ProtocolGuid,
 657                   (VOID **) &Dhcp,
 658                   gDhcp4DriverBinding.DriverBindingHandle,
 659                   ChildHandle,
 660                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
 661                   );
 662
 663   if (EFI_ERROR (Status)) {
 664     return EFI_UNSUPPORTED;
 665   }
 666
 667   Instance  = DHCP_INSTANCE_FROM_THIS (Dhcp);
 668   DhcpSb    = DHCP_SERVICE_FROM_THIS (This);
 669
 670   if (Instance->Service != DhcpSb) {
 671     return EFI_INVALID_PARAMETER;
 672   }
 673
 674   //
 675   // A child can be destroyed more than once. For example,
 676   // Dhcp4DriverBindingStop will destroy all of its children.
 677   // when caller driver is being stopped, it will destroy the
 678   // dhcp child it opens.
 679   //
 680   if (Instance->InDestroy) {
 681     return EFI_SUCCESS;
 682   }
 683
 684   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
 685   Instance->InDestroy = TRUE;
 686
 687   //
 688   // Close the Udp4 protocol.
 689   //
 690   gBS->CloseProtocol (
 691          DhcpSb->UdpIo->UdpHandle,
 692          &gEfiUdp4ProtocolGuid,
 693          gDhcp4DriverBinding.DriverBindingHandle,
 694          ChildHandle
 695          );
 696
 697   //
 698   // Uninstall the DHCP4 protocol first to enable a top down destruction.
 699   //
 700   gBS->RestoreTPL (OldTpl);
 701   Status = gBS->UninstallProtocolInterface (
 702                   ChildHandle,
 703                   &gEfiDhcp4ProtocolGuid,
 704                   Dhcp
 705                   );
 706   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
 707   if (EFI_ERROR (Status)) {
 708     Instance->InDestroy = FALSE;
 709
 710     gBS->RestoreTPL (OldTpl);
 711     return Status;
 712   }
 713
 714   if (DhcpSb->ActiveChild == Instance) {
 715     DhcpYieldControl (DhcpSb);
 716   }
 717
 718   RemoveEntryList (&Instance->Link);
 719   DhcpSb->NumChildren--;
 720
 721   if (Instance->UdpIo != NULL) {
 722     UdpIoCleanIo (Instance->UdpIo);
 723     gBS->CloseProtocol (
 724            Instance->UdpIo->UdpHandle,
 725            &gEfiUdp4ProtocolGuid,
 726            Instance->Service->Image,
 727            Instance->Handle
 728            );
 729     UdpIoFreeIo (Instance->UdpIo);
 730     Instance->UdpIo = NULL;
 731     Instance->Token = NULL;
 732   }
 733
 734   gBS->RestoreTPL (OldTpl);
 735
 736   FreePool (Instance);
 737   return EFI_SUCCESS;
 738 }