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 } 739