NetworkPkg: Add DNS feature support over IPv4 and IPv6.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: jiaxinwu <jiaxin.wu@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17854 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 762 insertions, 0 deletions

diff --git a/NetworkPkg/DnsDxe/DnsDhcp.c b/NetworkPkg/DnsDxe/DnsDhcp.c
new file mode 100644
index 0000000000..4607f7b633
--- /dev/null
+++ b/NetworkPkg/DnsDxe/DnsDhcp.c
@@ -0,0 +1,762 @@
+/** @file

+Functions implementation related with DHCPv4/v6 for DNS driver.

+

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

+This software and associated documentation (if any) is furnished

+under a license and may only be used or copied in accordance

+with the terms of the license. Except as permitted by such

+license, no part of this software or documentation may be

+reproduced, stored in a retrieval system, or transmitted in any

+form or by any means without the express written consent of

+Intel Corporation.

+

+**/

+

+#include "DnsImpl.h"

+

+/**

+  This function initialize the DHCP4 message instance.

+

+  This function will pad each item of dhcp4 message packet.

+

+  @param  Seed             Pointer to the message instance of the DHCP4 packet.

+  @param  InterfaceInfo    Pointer to the EFI_IP4_CONFIG2_INTERFACE_INFO instance.

+

+**/

+VOID

+DnsInitSeedPacket (

+  OUT EFI_DHCP4_PACKET               *Seed,

+  IN  EFI_IP4_CONFIG2_INTERFACE_INFO *InterfaceInfo

+  )

+{

+  EFI_DHCP4_HEADER           *Header;

+

+  //

+  // Get IfType and HwAddressSize from SNP mode data.

+  //

+  Seed->Size            = sizeof (EFI_DHCP4_PACKET);

+  Seed->Length          = sizeof (Seed->Dhcp4);

+  Header                = &Seed->Dhcp4.Header;

+  ZeroMem (Header, sizeof (EFI_DHCP4_HEADER));

+  Header->OpCode        = DHCP4_OPCODE_REQUEST;

+  Header->HwType        = InterfaceInfo->IfType;

+  Header->HwAddrLen     = (UINT8) InterfaceInfo->HwAddressSize;

+  CopyMem (Header->ClientHwAddr, &(InterfaceInfo->HwAddress), Header->HwAddrLen);

+

+  Seed->Dhcp4.Magik     = DHCP4_MAGIC;

+  Seed->Dhcp4.Option[0] = DHCP4_TAG_EOP;

+}

+

+/**

+  The common notify function. 

+

+  @param[in]  Event   The event signaled.

+  @param[in]  Context The context.

+

+**/

+VOID

+EFIAPI

+DhcpCommonNotify (

+  IN EFI_EVENT  Event,

+  IN VOID       *Context

+  )

+{

+  if ((Event == NULL) || (Context == NULL)) {

+    return ;

+  }

+

+  *((BOOLEAN *) Context) = TRUE;

+}

+

+/**

+  Parse the ACK to get required information

+

+  @param  Dhcp4            The DHCP4 protocol.

+  @param  Packet           Packet waiting for parse.

+  @param  DnsServerInfor   The required Dns4 server information.

+

+  @retval EFI_SUCCESS           The DNS information is got from the DHCP ACK.

+  @retval EFI_NO_MAPPING        DHCP failed to acquire address and other information.

+  @retval EFI_DEVICE_ERROR      Other errors as indicated.

+  @retval EFI_OUT_OF_RESOURCES  Failed to allocate memory.

+

+**/

+EFI_STATUS

+ParseDhcp4Ack (

+  IN EFI_DHCP4_PROTOCOL         *Dhcp4,

+  IN EFI_DHCP4_PACKET           *Packet,

+  IN DNS4_SERVER_INFOR          *DnsServerInfor

+  )

+{

+  EFI_STATUS              Status;

+  UINT32                  OptionCount;

+  EFI_DHCP4_PACKET_OPTION **OptionList;

+  UINT32                  ServerCount;

+  EFI_IPv4_ADDRESS        *ServerList;

+  UINT32                  Index;

+  UINT32                  Count;

+

+  ServerCount = 0;

+  ServerList = NULL;

+

+  OptionCount = 0;

+  OptionList  = NULL;

+

+  Status      = Dhcp4->Parse (Dhcp4, Packet, &OptionCount, OptionList);

+  if (Status != EFI_BUFFER_TOO_SMALL) {

+    return EFI_DEVICE_ERROR;

+  }

+

+  OptionList = AllocatePool (OptionCount * sizeof (EFI_DHCP4_PACKET_OPTION *));

+  if (OptionList == NULL) {

+    return EFI_OUT_OF_RESOURCES;

+  }

+

+  Status = Dhcp4->Parse (Dhcp4, Packet, &OptionCount, OptionList);

+  if (EFI_ERROR (Status)) {

+    gBS->FreePool (OptionList);

+    return EFI_DEVICE_ERROR;

+  }

+

+  Status = EFI_NOT_FOUND;

+

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

+    //

+    // Get DNS server addresses

+    //

+    if (OptionList[Index]->OpCode == DHCP4_TAG_DNS_SERVER) {

+

+      if (((OptionList[Index]->Length & 0x3) != 0) || (OptionList[Index]->Length == 0)) {

+        Status = EFI_DEVICE_ERROR;

+        break;

+      }

+

+      ServerCount = OptionList[Index]->Length/4;

+      ServerList = AllocatePool (ServerCount * sizeof (EFI_IPv4_ADDRESS));

+      if (ServerList == NULL) {

+        return EFI_OUT_OF_RESOURCES;

+      }

+

+      for(Count=0; Count < ServerCount; Count++){

+        CopyMem (ServerList + Count, &OptionList[Index]->Data[4 * Count], sizeof (EFI_IPv4_ADDRESS));

+      }

+

+      *(DnsServerInfor->ServerCount) = ServerCount;

+      DnsServerInfor->ServerList     = ServerList;

+

+      Status = EFI_SUCCESS;

+    }

+  }

+

+  gBS->FreePool (OptionList);

+  

+  return Status;

+}

+

+/**

+  EFI_DHCP6_INFO_CALLBACK is provided by the consumer of the EFI DHCPv6 Protocol 

+  instance to intercept events that occurs in the DHCPv6 Information Request

+  exchange process.

+

+  @param  This                  Pointer to the EFI_DHCP6_PROTOCOL instance that 

+                                is used to configure this  callback function.

+  @param  Context               Pointer to the context that is initialized in

+                                the EFI_DHCP6_PROTOCOL.InfoRequest().

+  @param  Packet                Pointer to Reply packet that has been received.

+                                The EFI DHCPv6 Protocol instance is responsible

+                                for freeing the buffer.

+

+  @retval EFI_SUCCESS           The DNS information is got from the DHCP ACK.

+  @retval EFI_DEVICE_ERROR      Other errors as indicated.

+  @retval EFI_OUT_OF_RESOURCES  Failed to allocate memory.

+**/

+EFI_STATUS

+EFIAPI

+ParseDhcp6Ack (

+  IN EFI_DHCP6_PROTOCOL          *This,

+  IN VOID                        *Context,

+  IN EFI_DHCP6_PACKET            *Packet

+  )

+{

+  EFI_STATUS                  Status;

+  UINT32                      OptionCount;

+  EFI_DHCP6_PACKET_OPTION     **OptionList;

+  DNS6_SERVER_INFOR           *DnsServerInfor;

+  UINT32                      ServerCount;

+  EFI_IPv6_ADDRESS            *ServerList;

+  UINT32                      Index;

+  UINT32                      Count;

+ 

+  OptionCount = 0;

+  ServerCount = 0;

+  ServerList  = NULL;

+  

+  Status      = This->Parse (This, Packet, &OptionCount, NULL);

+  if (Status != EFI_BUFFER_TOO_SMALL) {

+    return EFI_DEVICE_ERROR;

+  }

+

+  OptionList = AllocateZeroPool (OptionCount * sizeof (EFI_DHCP6_PACKET_OPTION *));

+  if (OptionList == NULL) {

+    return EFI_OUT_OF_RESOURCES;

+  }

+

+  Status = This->Parse (This, Packet, &OptionCount, OptionList);

+  if (EFI_ERROR (Status)) {

+    gBS->FreePool (OptionList);

+    return EFI_DEVICE_ERROR;

+  }

+  

+  DnsServerInfor = (DNS6_SERVER_INFOR *) Context;

+

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

+    OptionList[Index]->OpCode = NTOHS (OptionList[Index]->OpCode);

+    OptionList[Index]->OpLen  = NTOHS (OptionList[Index]->OpLen);

+

+    //

+    // Get DNS server addresses from this reply packet.

+    //

+    if (OptionList[Index]->OpCode == DHCP6_TAG_DNS_SERVER) {

+

+      if (((OptionList[Index]->OpLen & 0xf) != 0) || (OptionList[Index]->OpLen == 0)) {

+        Status = EFI_DEVICE_ERROR;

+        gBS->FreePool (OptionList);

+        return Status;

+      }

+      

+      ServerCount = OptionList[Index]->OpLen/16;

+      ServerList = AllocatePool (ServerCount * sizeof (EFI_IPv6_ADDRESS));

+      if (ServerList == NULL) {

+        gBS->FreePool (OptionList);

+        return EFI_OUT_OF_RESOURCES;

+      }

+

+      for(Count=0; Count < ServerCount; Count++){

+        CopyMem (ServerList + Count, &OptionList[Index]->Data[16 * Count], sizeof (EFI_IPv6_ADDRESS));

+      }

+

+      *(DnsServerInfor->ServerCount) = ServerCount;

+      DnsServerInfor->ServerList     = ServerList;

+    }

+  }

+

+  gBS->FreePool (OptionList);

+  

+  return Status;

+

+}

+

+/**

+  Parse the DHCP ACK to get Dns4 server information.

+

+  @param  Instance         The DNS instance.

+  @param  DnsServerCount   Retrieved Dns4 server Ip count.

+  @param  DnsServerList    Retrieved Dns4 server Ip list.

+

+  @retval EFI_SUCCESS           The Dns4 information is got from the DHCP ACK.

+  @retval EFI_OUT_OF_RESOURCES  Failed to allocate memory.

+  @retval EFI_NO_MEDIA          There was a media error.

+  @retval Others                Other errors as indicated.

+

+**/

+EFI_STATUS

+GetDns4ServerFromDhcp4 (

+  IN  DNS_INSTANCE               *Instance,

+  OUT UINT32                     *DnsServerCount,

+  OUT EFI_IPv4_ADDRESS           **DnsServerList

+  )

+{

+  EFI_STATUS                          Status;

+  EFI_HANDLE                          Image;

+  EFI_HANDLE                          Controller;

+  BOOLEAN                             MediaPresent;

+  EFI_HANDLE                          MnpChildHandle;  

+  EFI_MANAGED_NETWORK_PROTOCOL        *Mnp;

+  EFI_MANAGED_NETWORK_CONFIG_DATA     MnpConfigData;

+  EFI_HANDLE                          Dhcp4Handle;  

+  EFI_DHCP4_PROTOCOL                  *Dhcp4;

+  EFI_IP4_CONFIG2_PROTOCOL            *Ip4Config2;

+  UINTN                               DataSize;

+  VOID                                *Data;

+  EFI_IP4_CONFIG2_INTERFACE_INFO      *InterfaceInfo;

+  EFI_DHCP4_PACKET                    SeedPacket;

+  EFI_DHCP4_PACKET_OPTION             *ParaList[2];

+  DNS4_SERVER_INFOR                   DnsServerInfor;

+

+  EFI_DHCP4_TRANSMIT_RECEIVE_TOKEN    Token;

+  BOOLEAN                             IsDone;

+  UINTN                               Index;

+  

+  Image                      = Instance->Service->ImageHandle;

+  Controller                 = Instance->Service->ControllerHandle;

+

+  MnpChildHandle             = NULL;

+  Mnp                        = NULL;

+  

+  Dhcp4Handle                = NULL;

+  Dhcp4                      = NULL;

+

+  Ip4Config2                 = NULL;

+  DataSize                   = 0;

+  Data                       = NULL;

+  InterfaceInfo              = NULL;

+

+  ZeroMem (&MnpConfigData, sizeof (EFI_MANAGED_NETWORK_CONFIG_DATA));

+  

+  ZeroMem (&DnsServerInfor, sizeof (DNS4_SERVER_INFOR));

+  

+  ZeroMem (&Token, sizeof (EFI_DHCP4_TRANSMIT_RECEIVE_TOKEN));

+  

+  DnsServerInfor.ServerCount = DnsServerCount;

+

+  IsDone = FALSE;

+

+  //

+  // Check media.

+  //

+  MediaPresent = TRUE;

+  NetLibDetectMedia (Controller, &MediaPresent);

+  if (!MediaPresent) {

+    return EFI_NO_MEDIA;

+  }

+

+  //

+  // Create a Mnp child instance, get the protocol and config for it.

+  //

+  Status = NetLibCreateServiceChild (

+             Controller,

+             Image,

+             &gEfiManagedNetworkServiceBindingProtocolGuid,

+             &MnpChildHandle

+             );

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  Status = gBS->OpenProtocol (

+                  MnpChildHandle,

+                  &gEfiManagedNetworkProtocolGuid,

+                  (VOID **) &Mnp,

+                  Image,

+                  Controller,

+                  EFI_OPEN_PROTOCOL_BY_DRIVER

+                  );

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+  

+  MnpConfigData.ReceivedQueueTimeoutValue = 0;

+  MnpConfigData.TransmitQueueTimeoutValue = 0;

+  MnpConfigData.ProtocolTypeFilter        = IP4_ETHER_PROTO;

+  MnpConfigData.EnableUnicastReceive      = TRUE;

+  MnpConfigData.EnableMulticastReceive    = TRUE;

+  MnpConfigData.EnableBroadcastReceive    = TRUE;

+  MnpConfigData.EnablePromiscuousReceive  = FALSE;

+  MnpConfigData.FlushQueuesOnReset        = TRUE;

+  MnpConfigData.EnableReceiveTimestamps   = FALSE;

+  MnpConfigData.DisableBackgroundPolling  = FALSE;

+

+  Status = Mnp->Configure(Mnp, &MnpConfigData);

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+  

+  //

+  // Create a DHCP4 child instance and get the protocol.

+  //

+  Status = NetLibCreateServiceChild (

+             Controller,

+             Image,

+             &gEfiDhcp4ServiceBindingProtocolGuid,

+             &Dhcp4Handle

+             );

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+

+  Status = gBS->OpenProtocol (

+                  Dhcp4Handle,

+                  &gEfiDhcp4ProtocolGuid,

+                  (VOID **) &Dhcp4,

+                  Image,

+                  Controller,

+                  EFI_OPEN_PROTOCOL_BY_DRIVER

+                  );

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+

+  //

+  // Get Ip4Config2 instance info.

+  //

+  Status = gBS->HandleProtocol (Controller, &gEfiIp4Config2ProtocolGuid, (VOID **) &Ip4Config2);

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+  

+  Status = Ip4Config2->GetData (Ip4Config2, Ip4Config2DataTypeInterfaceInfo, &DataSize, Data);

+  if (EFI_ERROR (Status) && Status != EFI_BUFFER_TOO_SMALL) {

+    goto ON_EXIT;

+  }

+

+  Data = AllocateZeroPool (DataSize);

+  if (Data == NULL) {

+    Status = EFI_OUT_OF_RESOURCES;

+    goto ON_EXIT;

+  }

+

+  Status = Ip4Config2->GetData (Ip4Config2, Ip4Config2DataTypeInterfaceInfo, &DataSize, Data);

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+

+  InterfaceInfo = (EFI_IP4_CONFIG2_INTERFACE_INFO *)Data;

+  

+  //

+  // Build required Token.

+  //

+  Status = gBS->CreateEvent (

+                  EVT_NOTIFY_SIGNAL,

+                  TPL_NOTIFY,

+                  DhcpCommonNotify,

+                  &IsDone,

+                  &Token.CompletionEvent

+                  );

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+  

+  SetMem (&Token.RemoteAddress, sizeof (EFI_IPv4_ADDRESS), 0xff);

+  

+  Token.RemotePort = 67;

+

+  Token.ListenPointCount = 1;

+  

+  Token.ListenPoints = AllocateZeroPool (Token.ListenPointCount * sizeof (EFI_DHCP4_LISTEN_POINT));

+  if (Token.ListenPoints == NULL) {

+    Status = EFI_OUT_OF_RESOURCES;

+    goto ON_EXIT;

+  }

+

+  if (Instance->Dns4CfgData.UseDefaultSetting) {

+    CopyMem (&(Token.ListenPoints[0].ListenAddress), &(InterfaceInfo->StationAddress), sizeof (EFI_IPv4_ADDRESS));

+    CopyMem (&(Token.ListenPoints[0].SubnetMask), &(InterfaceInfo->SubnetMask), sizeof (EFI_IPv4_ADDRESS));

+  } else {

+    CopyMem (&(Token.ListenPoints[0].ListenAddress), &(Instance->Dns4CfgData.StationIp), sizeof (EFI_IPv4_ADDRESS));

+    CopyMem (&(Token.ListenPoints[0].SubnetMask), &(Instance->Dns4CfgData.SubnetMask), sizeof (EFI_IPv4_ADDRESS));

+  }

+  

+  Token.ListenPoints[0].ListenPort = 68;

+  

+  Token.TimeoutValue = DNS_TIME_TO_GETMAP;

+

+  DnsInitSeedPacket (&SeedPacket, InterfaceInfo);

+

+  ParaList[0] = AllocateZeroPool (sizeof (EFI_DHCP4_PACKET_OPTION));

+  if (ParaList[0] == NULL) {

+    Status = EFI_OUT_OF_RESOURCES;

+    goto ON_EXIT;

+  }

+  

+  ParaList[0]->OpCode  = DHCP4_TAG_TYPE;

+  ParaList[0]->Length  = 1;

+  ParaList[0]->Data[0] = DHCP4_MSG_INFORM;

+  

+  ParaList[1] = AllocateZeroPool (sizeof (EFI_DHCP4_PACKET_OPTION));

+  if (ParaList[1] == NULL) {

+    Status = EFI_OUT_OF_RESOURCES;

+    goto ON_EXIT;

+  }

+  

+  ParaList[1]->OpCode  = DHCP4_TAG_PARA_LIST;

+  ParaList[1]->Length  = 1;

+  ParaList[1]->Data[0] = DHCP4_TAG_DNS_SERVER;

+

+  Status = Dhcp4->Build (Dhcp4, &SeedPacket, 0, NULL, 2, ParaList, &Token.Packet); 

+

+  Token.Packet->Dhcp4.Header.Xid      = HTONL(NET_RANDOM (NetRandomInitSeed ()));

+  

+  Token.Packet->Dhcp4.Header.Reserved = HTONS ((UINT16)0x8000);

+  

+  if (Instance->Dns4CfgData.UseDefaultSetting) {

+    CopyMem (&(Token.Packet->Dhcp4.Header.ClientAddr), &(InterfaceInfo->StationAddress), sizeof (EFI_IPv4_ADDRESS));

+  } else {

+    CopyMem (&(Token.Packet->Dhcp4.Header.ClientAddr), &(Instance->Dns4CfgData.StationIp), sizeof (EFI_IPv4_ADDRESS));

+  }

+  

+  CopyMem (Token.Packet->Dhcp4.Header.ClientHwAddr, &(InterfaceInfo->HwAddress), InterfaceInfo->HwAddressSize); 

+  

+  Token.Packet->Dhcp4.Header.HwAddrLen = (UINT8)(InterfaceInfo->HwAddressSize);

+

+  //

+  // TransmitReceive Token

+  //

+  Status = Dhcp4->TransmitReceive (Dhcp4, &Token);

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+

+  //

+  // Poll the packet

+  //

+  do {

+    Status = Mnp->Poll (Mnp);

+  } while (!IsDone);

+  

+  //

+  // Parse the ACK to get required information if received done.

+  //

+  if (IsDone && !EFI_ERROR (Token.Status)) {

+    for (Index = 0; Index < Token.ResponseCount; Index++) {

+      Status = ParseDhcp4Ack (Dhcp4, &Token.ResponseList[Index], &DnsServerInfor);

+      if (!EFI_ERROR (Status)) {

+        break;

+      }

+    }

+

+    *DnsServerList = DnsServerInfor.ServerList;

+  } else {

+    Status = Token.Status;

+  }

+  

+ON_EXIT:

+

+  if (Data != NULL) {

+    FreePool (Data);

+  }

+

+  for (Index = 0; Index < 2; Index++) {

+    if (ParaList[Index] != NULL) {

+      FreePool (ParaList[Index]);

+    }

+  }

+

+  if (Token.ListenPoints) {

+    FreePool (Token.ListenPoints);

+  }

+

+  if (Token.Packet) {

+    FreePool (Token.Packet);

+  }

+  

+  if (Token.ResponseList != NULL) {

+    FreePool (Token.ResponseList);

+  }

+  

+  if (Token.CompletionEvent != NULL) {

+    gBS->CloseEvent (Token.CompletionEvent);

+  }

+  

+  if (Dhcp4 != NULL) {

+    Dhcp4->Stop (Dhcp4);

+    Dhcp4->Configure (Dhcp4, NULL);

+

+    gBS->CloseProtocol (

+           Dhcp4Handle,

+           &gEfiDhcp4ProtocolGuid,

+           Image,

+           Controller

+           );

+  }

+  

+  if (Dhcp4Handle != NULL) {

+    NetLibDestroyServiceChild (

+      Controller,

+      Image,

+      &gEfiDhcp4ServiceBindingProtocolGuid,

+      Dhcp4Handle

+      );

+  }

+

+  if (Mnp != NULL) {

+    Mnp->Configure (Mnp, NULL);

+

+    gBS->CloseProtocol (

+           MnpChildHandle,

+           &gEfiManagedNetworkProtocolGuid,

+           Image,

+           Controller

+           );

+  }

+  

+  NetLibDestroyServiceChild (

+    Controller,

+    Image,

+    &gEfiManagedNetworkServiceBindingProtocolGuid,

+    MnpChildHandle

+    );

+  

+  return Status;

+}

+

+/**

+  Parse the DHCP ACK to get Dns6 server information.

+

+  @param  Image            The handle of the driver image.

+  @param  Controller       The handle of the controller.

+  @param  DnsServerCount   Retrieved Dns6 server Ip count.

+  @param  DnsServerList    Retrieved Dns6 server Ip list.

+

+  @retval EFI_SUCCESS           The Dns6 information is got from the DHCP ACK.

+  @retval EFI_OUT_OF_RESOURCES  Failed to allocate memory.

+  @retval EFI_NO_MEDIA          There was a media error.

+  @retval Others                Other errors as indicated.

+

+**/

+EFI_STATUS

+GetDns6ServerFromDhcp6 (

+  IN  EFI_HANDLE                 Image,

+  IN  EFI_HANDLE                 Controller,

+  OUT UINT32                     *DnsServerCount,

+  OUT EFI_IPv6_ADDRESS           **DnsServerList

+  )

+{

+  EFI_HANDLE                Dhcp6Handle;

+  EFI_DHCP6_PROTOCOL        *Dhcp6;

+  EFI_STATUS                Status;

+  EFI_STATUS                TimerStatus;

+  EFI_DHCP6_PACKET_OPTION   *Oro;

+  EFI_DHCP6_RETRANSMISSION  InfoReqReXmit;

+  EFI_EVENT                 Timer;

+  BOOLEAN                   MediaPresent;

+  DNS6_SERVER_INFOR         DnsServerInfor;

+

+  Dhcp6Handle = NULL;

+  Dhcp6       = NULL;

+  Oro         = NULL;

+  Timer       = NULL;

+

+  ZeroMem (&DnsServerInfor, sizeof (DNS6_SERVER_INFOR));

+

+  DnsServerInfor.ServerCount = DnsServerCount;

+

+  //

+  // Check media status before doing DHCP.

+  //

+  MediaPresent = TRUE;

+  NetLibDetectMedia (Controller, &MediaPresent);

+  if (!MediaPresent) {

+    return EFI_NO_MEDIA;

+  }

+

+  //

+  // Create a DHCP6 child instance and get the protocol.

+  //

+  Status = NetLibCreateServiceChild (

+             Controller,

+             Image,

+             &gEfiDhcp6ServiceBindingProtocolGuid,

+             &Dhcp6Handle

+             );

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  Status = gBS->OpenProtocol (

+                  Dhcp6Handle,

+                  &gEfiDhcp6ProtocolGuid,

+                  (VOID **) &Dhcp6,

+                  Image,

+                  Controller,

+                  EFI_OPEN_PROTOCOL_BY_DRIVER

+                  );

+  if (EFI_ERROR (Status)) {

+    goto ON_EXIT;

+  }

+

+  Oro = AllocateZeroPool (sizeof (EFI_DHCP6_PACKET_OPTION) + 1);

+  if (Oro == NULL) {

+    Status = EFI_OUT_OF_RESOURCES;

+    goto ON_EXIT;

+  }

+

+  //

+  // Ask the server to reply with DNS options.

+  // All members in EFI_DHCP6_PACKET_OPTION are in network order.

+  //

+  Oro->OpCode  = HTONS (DHCP6_TAG_DNS_REQUEST);

+  Oro->OpLen   = HTONS (2);

+  Oro->Data[1] = DHCP6_TAG_DNS_SERVER;

+

+  InfoReqReXmit.Irt = 4;

+  InfoReqReXmit.Mrc = 1;

+  InfoReqReXmit.Mrt = 10;

+  InfoReqReXmit.Mrd = 30;

+

+  Status = Dhcp6->InfoRequest (

+                    Dhcp6,

+                    TRUE,

+                    Oro,

+                    0,

+                    NULL,

+                    &InfoReqReXmit,

+                    NULL,

+                    ParseDhcp6Ack,

+                    &DnsServerInfor

+                    );

+  if (Status == EFI_NO_MAPPING) {

+    Status = gBS->CreateEvent (EVT_TIMER, TPL_CALLBACK, NULL, NULL, &Timer);

+    if (EFI_ERROR (Status)) {

+      goto ON_EXIT;

+    }

+

+    Status = gBS->SetTimer (

+                    Timer,

+                    TimerRelative,

+                    DNS_TIME_TO_GETMAP * TICKS_PER_SECOND

+                    );

+

+    if (EFI_ERROR (Status)) {

+      goto ON_EXIT;

+    }

+

+    do {

+      TimerStatus = gBS->CheckEvent (Timer);

+      if (!EFI_ERROR (TimerStatus)) {

+        Status = Dhcp6->InfoRequest (

+                          Dhcp6,

+                          TRUE,

+                          Oro,

+                          0,

+                          NULL,

+                          &InfoReqReXmit,

+                          NULL,

+                          ParseDhcp6Ack,

+                          &DnsServerInfor

+                          );

+      }

+    } while (TimerStatus == EFI_NOT_READY);

+  }

+  

+  *DnsServerList  = DnsServerInfor.ServerList;

+

+ON_EXIT:

+

+  if (Oro != NULL) {

+    FreePool (Oro);

+  }  

+

+  if (Timer != NULL) {

+    gBS->CloseEvent (Timer);

+  }

+

+  if (Dhcp6 != NULL) {

+    gBS->CloseProtocol (

+           Dhcp6Handle,

+           &gEfiDhcp6ProtocolGuid,

+           Image,

+           Controller

+           );

+  }

+

+  NetLibDestroyServiceChild (

+    Controller,

+    Image,

+    &gEfiDhcp6ServiceBindingProtocolGuid,

+    Dhcp6Handle

+    );

+

+  return Status;

+  

+}

+