path: root/MdeModulePkg/Universal/Network/MnpDxe/MnpConfig.c

/** @file

Copyright (c) 2005 - 2008, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

Module Name:

  MnpConfig.c

Abstract:

  Implementation of Managed Network Protocol private services.


**/


#include "MnpImpl.h"

EFI_SERVICE_BINDING_PROTOCOL    mMnpServiceBindingProtocol = {
  MnpServiceBindingCreateChild,
  MnpServiceBindingDestroyChild
};

EFI_MANAGED_NETWORK_PROTOCOL    mMnpProtocolTemplate = {
  MnpGetModeData,
  MnpConfigure,
  MnpMcastIpToMac,
  MnpGroups,
  MnpTransmit,
  MnpReceive,
  MnpCancel,
  MnpPoll
};

EFI_MANAGED_NETWORK_CONFIG_DATA mMnpDefaultConfigData = {
  10000,
  10000,
  0,
  FALSE,
  FALSE,
  FALSE,
  FALSE,
  FALSE,
  FALSE,
  FALSE
};

STATIC
EFI_STATUS
MnpAddFreeNbuf (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN UINTN             Count
  );

STATIC
EFI_STATUS
MnpStartSnp (
  IN EFI_SIMPLE_NETWORK_PROTOCOL  *Snp
  );

STATIC
EFI_STATUS
MnpStopSnp (
  IN EFI_SIMPLE_NETWORK_PROTOCOL  *Snp
  );

STATIC
EFI_STATUS
MnpStart (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN BOOLEAN           IsConfigUpdate,
  IN BOOLEAN           EnableSystemPoll
  );

STATIC
EFI_STATUS
MnpStop (
  IN MNP_SERVICE_DATA  *MnpServiceData
  );

STATIC
EFI_STATUS
MnpConfigReceiveFilters (
  IN MNP_SERVICE_DATA  *MnpServiceData
  );

STATIC
EFI_STATUS
MnpGroupOpAddCtrlBlk (
  IN MNP_INSTANCE_DATA        *Instance,
  IN MNP_GROUP_CONTROL_BLOCK  *CtrlBlk,
  IN MNP_GROUP_ADDRESS        *GroupAddress OPTIONAL,
  IN EFI_MAC_ADDRESS          *MacAddress,
  IN UINT32                   HwAddressSize
  );

STATIC
BOOLEAN
MnpGroupOpDelCtrlBlk (
  IN MNP_INSTANCE_DATA        *Instance,
  IN MNP_GROUP_CONTROL_BLOCK  *CtrlBlk
  );


/**
  Add some NET_BUF into MnpServiceData->FreeNbufQue. The buffer length of
  the NET_BUF is specified by MnpServiceData->BufferLength.

  @param  MnpServiceData        Pointer to the MNP_SERVICE_DATA.
  @param  Count                 Number of NET_BUFFERs to add.

  @retval EFI_SUCCESS           The specified amount of NET_BUFs are allocated and
                                added into MnpServiceData->FreeNbufQue.
  @retval EFI_OUT_OF_RESOURCES  Failed to allocate a NET_BUF structure.

**/
STATIC
EFI_STATUS
MnpAddFreeNbuf (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN UINTN             Count
  )
{
  EFI_STATUS  Status;
  UINTN       Index;
  NET_BUF     *Nbuf;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);
  ASSERT ((Count > 0) && (MnpServiceData->BufferLength > 0));

  Status = EFI_SUCCESS;

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

    Nbuf = NetbufAlloc (MnpServiceData->BufferLength + MnpServiceData->PaddingSize);
    if (Nbuf == NULL) {

      DEBUG ((EFI_D_ERROR, "MnpAddFreeNbuf: NetBufAlloc failed.\n"));
      Status = EFI_OUT_OF_RESOURCES;
      break;
    }

    if (MnpServiceData->PaddingSize > 0) {
      //
      // Pad padding bytes before the media header
      //
      NetbufAllocSpace (Nbuf, MnpServiceData->PaddingSize, NET_BUF_TAIL);
      NetbufTrim (Nbuf, MnpServiceData->PaddingSize, NET_BUF_HEAD);
    }

    NetbufQueAppend (&MnpServiceData->FreeNbufQue, Nbuf);
  }

  MnpServiceData->NbufCnt += Index;

  return Status;
}


/**
  Allocate a free NET_BUF from MnpServiceData->FreeNbufQue. If there is none
  in the queue, first try to allocate some and add them into the queue, then
  fetch the NET_BUF from the updated FreeNbufQue.

  @param  MnpServiceData        Pointer to the MNP_SERVICE_DATA.

  @return Pointer to the allocated free NET_BUF structure, if NULL the operation is failed.

**/
NET_BUF *
MnpAllocNbuf (
  IN MNP_SERVICE_DATA  *MnpServiceData
  )
{
  EFI_STATUS    Status;
  NET_BUF_QUEUE *FreeNbufQue;
  NET_BUF       *Nbuf;
  EFI_TPL       OldTpl;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  FreeNbufQue = &MnpServiceData->FreeNbufQue;

  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);

  //
  // Check whether there are available buffers, or else try to add some.
  //
  if (FreeNbufQue->BufNum == 0) {

    if ((MnpServiceData->NbufCnt + MNP_NET_BUFFER_INCREASEMENT) > MNP_MAX_NET_BUFFER_NUM) {

      DEBUG (
        (EFI_D_ERROR,
        "MnpAllocNbuf: The maximum NET_BUF size is reached for MNP driver instance %p.\n",
        MnpServiceData)
        );

      Nbuf = NULL;
      goto ON_EXIT;
    }

    Status = MnpAddFreeNbuf (MnpServiceData, MNP_NET_BUFFER_INCREASEMENT);
    if (EFI_ERROR (Status)) {

      DEBUG (
        (EFI_D_ERROR,
        "MnpAllocNbuf: Failed to add NET_BUFs into the FreeNbufQue, %r.\n",
        Status)
        );
      //
      // Don't return NULL, perhaps MnpAddFreeNbuf does add some NET_BUFs but
      // the amount is less than MNP_NET_BUFFER_INCREASEMENT.
      //
    }
  }

  Nbuf = NetbufQueRemove (FreeNbufQue);

  //
  // Increase the RefCnt.
  //
  if (Nbuf != NULL) {
    NET_GET_REF (Nbuf);
  }

ON_EXIT:
  gBS->RestoreTPL (OldTpl);

  return Nbuf;
}


/**
  Try to reclaim the Nbuf into the buffer pool.

  @param  MnpServiceData        Pointer to the mnp service context data.
  @param  Nbuf                  Pointer to the NET_BUF to free.

  @return None.

**/
VOID
MnpFreeNbuf (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN NET_BUF           *Nbuf
  )
{
  EFI_TPL  OldTpl;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);
  ASSERT (Nbuf->RefCnt > 1);

  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);

  NET_PUT_REF (Nbuf);

  if (Nbuf->RefCnt == 1) {
    //
    // Trim all buffer contained in the Nbuf, then append it to the NbufQue.
    //
    NetbufTrim (Nbuf, Nbuf->TotalSize, NET_BUF_TAIL);
    NetbufQueAppend (&MnpServiceData->FreeNbufQue, Nbuf);
  }

  gBS->RestoreTPL (OldTpl);
}


/**
  Initialize the mnp service context data.

  @param  MnpServiceData        Pointer to the mnp service context data.
  @param  Snp                   Pointer to the simple network protocol.

  @retval EFI_SUCCESS           The mnp service context is initialized.
  @retval Other                 Some error occurs.

**/
EFI_STATUS
MnpInitializeServiceData (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN EFI_HANDLE        ImageHandle,
  IN EFI_HANDLE        ControllerHandle
  )
{
  EFI_STATUS                   Status;
  EFI_SIMPLE_NETWORK_PROTOCOL  *Snp;
  EFI_SIMPLE_NETWORK_MODE      *SnpMode;

  MnpServiceData->Signature = MNP_SERVICE_DATA_SIGNATURE;

  MnpServiceData->ControllerHandle = ControllerHandle;

  //
  // Copy the ServiceBinding structure.
  //
  MnpServiceData->ServiceBinding = mMnpServiceBindingProtocol;

  //
  // Open the Simple Network protocol.
  //
  Status = gBS->OpenProtocol (
                  ControllerHandle,
                  &gEfiSimpleNetworkProtocolGuid,
                  (VOID **) &Snp,
                  ImageHandle,
                  ControllerHandle,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    return EFI_UNSUPPORTED;
  }

  //
  // Get MTU from Snp.
  //
  SnpMode             = Snp->Mode;
  MnpServiceData->Snp = Snp;
  MnpServiceData->Mtu = SnpMode->MaxPacketSize;

  //
  // Initialize the lists.
  //
  InitializeListHead (&MnpServiceData->GroupAddressList);
  InitializeListHead (&MnpServiceData->ChildrenList);

  //
  // Get the buffer length used to allocate NET_BUF to hold data received
  // from SNP. Do this before fill the FreeNetBufQue.
  //
  MnpServiceData->BufferLength = MnpServiceData->Mtu + SnpMode->MediaHeaderSize + NET_ETHER_FCS_SIZE;

  //
  // Make sure the protocol headers immediately following the media header
  // 4-byte aligned
  //
  MnpServiceData->PaddingSize = (4 - SnpMode->MediaHeaderSize) & 0x3;

  //
  // Initialize the FreeNetBufQue and pre-allocate some NET_BUFs.
  //
  NetbufQueInit (&MnpServiceData->FreeNbufQue);
  Status = MnpAddFreeNbuf (MnpServiceData, MNP_INIT_NET_BUFFER_NUM);
  if (EFI_ERROR (Status)) {

    DEBUG ((EFI_D_ERROR, "MnpInitializeServiceData: MnpAddFreeNbuf failed, %r.\n", Status));
    goto ERROR;
  }
  //
  // Get one NET_BUF from the FreeNbufQue for rx cache.
  //
  MnpServiceData->RxNbufCache = MnpAllocNbuf (MnpServiceData);
  NetbufAllocSpace (
    MnpServiceData->RxNbufCache,
    MnpServiceData->BufferLength,
    NET_BUF_TAIL
    );

  //
  // Allocate buffer pool for tx.
  //
  MnpServiceData->TxBuf = AllocatePool (MnpServiceData->Mtu + SnpMode->MediaHeaderSize);
  if (MnpServiceData->TxBuf == NULL) {

    DEBUG ((EFI_D_ERROR, "MnpInitializeServiceData: AllocatePool failed.\n"));
    Status = EFI_OUT_OF_RESOURCES;

    goto ERROR;
  }

  //
  // Create the system poll timer.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL | EVT_TIMER,
                  TPL_CALLBACK,
                  MnpSystemPoll,
                  MnpServiceData,
                  &MnpServiceData->PollTimer
                  );
  if (EFI_ERROR (Status)) {

    DEBUG ((EFI_D_ERROR, "MnpInitializeServiceData: CreateEvent for poll timer failed.\n"));
    goto ERROR;
  }

  //
  // Create the timer for packet timeout check.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL | EVT_TIMER,
                  TPL_CALLBACK,
                  MnpCheckPacketTimeout,
                  MnpServiceData,
                  &MnpServiceData->TimeoutCheckTimer
                  );
  if (EFI_ERROR (Status)) {

    DEBUG ((EFI_D_ERROR, "MnpInitializeServiceData: CreateEvent for packet timeout check failed.\n"));
    goto ERROR;
  }

  //
  // Create the timer for tx timeout check.
  //
  Status = gBS->CreateEvent (
                  EVT_TIMER,
                  TPL_CALLBACK,
                  NULL,
                  NULL,
                  &MnpServiceData->TxTimeoutEvent
                  );
  if (EFI_ERROR (Status)) {

    DEBUG ((EFI_D_ERROR, "MnpInitializeServiceData: CreateEvent for tx timeout event failed.\n"));
  }

ERROR:

  if (EFI_ERROR (Status)) {
    //
    // Free the dynamic allocated resources if necessary.
    //
    if (MnpServiceData->TimeoutCheckTimer != NULL) {

      gBS->CloseEvent (MnpServiceData->TimeoutCheckTimer);
    }

    if (MnpServiceData->PollTimer != NULL) {

      gBS->CloseEvent (MnpServiceData->PollTimer);
    }

    if (MnpServiceData->TxBuf != NULL) {

      gBS->FreePool (MnpServiceData->TxBuf);
    }

    if (MnpServiceData->RxNbufCache != NULL) {

      MnpFreeNbuf (MnpServiceData, MnpServiceData->RxNbufCache);
    }

    if (MnpServiceData->FreeNbufQue.BufNum != 0) {

      NetbufQueFlush (&MnpServiceData->FreeNbufQue);
    }
  }

  return Status;
}


/**
  Flush the mnp service context data.

  @param  MnpServiceData        Pointer to the mnp service context data.

  @return None.

**/
VOID
MnpFlushServiceData (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN EFI_HANDLE        ImageHandle
  )
{
  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  //
  // The GroupAddressList must be empty.
  //
  ASSERT (IsListEmpty (&MnpServiceData->GroupAddressList));

  //
  // Close the event.
  //
  gBS->CloseEvent (&MnpServiceData->TxTimeoutEvent);
  gBS->CloseEvent (&MnpServiceData->TimeoutCheckTimer);
  gBS->CloseEvent (&MnpServiceData->PollTimer);

  //
  // Free the tx buffer.
  //
  gBS->FreePool (MnpServiceData->TxBuf);

  //
  // Free the RxNbufCache.
  //
  MnpFreeNbuf (MnpServiceData, MnpServiceData->RxNbufCache);

  //
  // Flush the FreeNbufQue.
  //
  MnpServiceData->NbufCnt -= MnpServiceData->FreeNbufQue.BufNum;
  NetbufQueFlush (&MnpServiceData->FreeNbufQue);

  DEBUG_CODE (

  if (MnpServiceData->NbufCnt != 0) {

    DEBUG ((EFI_D_WARN, "MnpFlushServiceData: Memory leak, MnpServiceData->NbufCnt != 0.\n"));
  }
  );

  //
  // Close the Simple Network Protocol.
  //
  gBS->CloseProtocol (
        MnpServiceData->ControllerHandle,
        &gEfiSimpleNetworkProtocolGuid,
        ImageHandle,
        MnpServiceData->ControllerHandle
        );
}


/**
  Initialize the mnp instance context data.

  @param  MnpServiceData        Pointer to the mnp service context data.
  @param  Instance              Pointer to the mnp instance context data to
                                initialize.

  @return None.

**/
VOID
MnpInitializeInstanceData (
  IN MNP_SERVICE_DATA   *MnpServiceData,
  IN MNP_INSTANCE_DATA  *Instance
  )
{
  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);
  ASSERT (Instance != NULL);

  //
  // Set the signature.
  //
  Instance->Signature = MNP_INSTANCE_DATA_SIGNATURE;

  //
  // Copy the MNP Protocol interfaces from the template.
  //
  CopyMem (&Instance->ManagedNetwork, &mMnpProtocolTemplate, sizeof (Instance->ManagedNetwork));

  //
  // Copy the default config data.
  //
  CopyMem (&Instance->ConfigData, &mMnpDefaultConfigData, sizeof (Instance->ConfigData));

  //
  // Initialize the lists.
  //
  InitializeListHead (&Instance->GroupCtrlBlkList);
  InitializeListHead (&Instance->RcvdPacketQueue);
  InitializeListHead (&Instance->RxDeliveredPacketQueue);

  //
  // Initialize the RxToken Map.
  //
  NetMapInit (&Instance->RxTokenMap);

  //
  // Save the MnpServiceData info.
  //
  Instance->MnpServiceData = MnpServiceData;
}


/**
  Check whether the token specified by Arg maches the token in Item.

  @param  Map                   Pointer to the NET_MAP.
  @param  Item                  Pointer to the NET_MAP_ITEM
  @param  Arg                   Pointer to the Arg, it's a pointer to the token to
                                check.

  @retval EFI_SUCCESS           The token specified by Arg is different from the
                                token in Item.
  @retval EFI_ACCESS_DENIED     The token specified by Arg is the same as that in
                                Item.

**/
EFI_STATUS
MnpTokenExist (
  IN NET_MAP       *Map,
  IN NET_MAP_ITEM  *Item,
  IN VOID          *Arg
  )
{
  EFI_MANAGED_NETWORK_COMPLETION_TOKEN  *Token;
  EFI_MANAGED_NETWORK_COMPLETION_TOKEN  *TokenInItem;

  Token       = (EFI_MANAGED_NETWORK_COMPLETION_TOKEN *) Arg;
  TokenInItem = (EFI_MANAGED_NETWORK_COMPLETION_TOKEN *) Item->Key;

  if ((Token == TokenInItem) || (Token->Event == TokenInItem->Event)) {
    //
    // The token is the same either the two tokens equals or the Events in
    // the two tokens are the same.
    //
    return EFI_ACCESS_DENIED;
  }

  return EFI_SUCCESS;
}


/**
  Cancel the token specified by Arg if it matches the token in Item.

  @param  Map                   Pointer to the NET_MAP.
  @param  Item                  Pointer to the NET_MAP_ITEM
  @param  Arg                   Pointer to the Arg, it's a pointer to the token to
                                cancel.

  @retval EFI_SUCCESS           The Arg is NULL, and the token in Item is
                                cancelled, or the Arg isn't NULL, and the token in
                                Item is different from the Arg.
  @retval EFI_ABORTED           The Arg isn't NULL, the token in Item mathces the
                                Arg, and the token is cancelled.

**/
EFI_STATUS
MnpCancelTokens (
  IN NET_MAP       *Map,
  IN NET_MAP_ITEM  *Item,
  IN VOID          *Arg
  )
{
  EFI_MANAGED_NETWORK_COMPLETION_TOKEN  *TokenToCancel;

  if ((Arg != NULL) && (Item->Key != Arg)) {
    //
    // The token in Item is not the token specified by Arg.
    //
    return EFI_SUCCESS;
  }

  TokenToCancel         = (EFI_MANAGED_NETWORK_COMPLETION_TOKEN *) Item->Key;

  //
  // Remove the item from the map.
  //
  NetMapRemoveItem (Map, Item, NULL);

  //
  // Cancel this token with status set to EFI_ABORTED.
  //
  TokenToCancel->Status = EFI_ABORTED;
  gBS->SignalEvent (TokenToCancel->Event);

  if (Arg != NULL) {
    //
    // Only abort the token specified by Arg if Arg isn't NULL.
    //
    return EFI_ABORTED;
  }

  return EFI_SUCCESS;
}


/**
  Start and initialize the simple network.

  @param  Snp                   Pointer to the simple network protocol.

  @retval EFI_SUCCESS           The simple network protocol is started.
  @retval Other                 Some error occurs.

**/
STATIC
EFI_STATUS
MnpStartSnp (
  IN EFI_SIMPLE_NETWORK_PROTOCOL  *Snp
  )
{
  EFI_STATUS  Status;

  ASSERT (Snp != NULL);

  //
  // Start the simple network.
  //
  Status = Snp->Start (Snp);

  if (!EFI_ERROR (Status)) {
    //
    // Initialize the simple network.
    //
    Status  = Snp->Initialize (Snp, 0, 0);
  }

  return Status;
}


/**
  Stop the simple network.

  @param  Snp                   Pointer to the simple network protocol.

  @retval EFI_SUCCESS           The simple network is stopped.
  @retval Other                 Some error occurs.

**/
STATIC
EFI_STATUS
MnpStopSnp (
  IN EFI_SIMPLE_NETWORK_PROTOCOL  *Snp
  )
{
  EFI_STATUS  Status;

  ASSERT (Snp != NULL);

  //
  // Shut down the simple network.
  //
  Status = Snp->Shutdown (Snp);

  if (!EFI_ERROR (Status)) {
    //
    // Stop the simple network.
    //
    Status = Snp->Stop (Snp);
  }

  return Status;
}


/**
  Start the managed network, this function is called when one instance is configured
  or reconfigured.

  @param  MnpServiceData        Pointer to the mnp service context data.
  @param  IsConfigUpdate        The instance is reconfigured or it's the first time
                                 the instanced is configured.
  @param  EnableSystemPoll      Enable the system polling or not.

  @retval EFI_SUCCESS           The managed network is started and some
                                configuration is updated.
  @retval Other                 Some error occurs.

**/
STATIC
EFI_STATUS
MnpStart (
  IN MNP_SERVICE_DATA  *MnpServiceData,
  IN BOOLEAN           IsConfigUpdate,
  IN BOOLEAN           EnableSystemPoll
  )
{
  EFI_STATUS      Status;
  EFI_TIMER_DELAY TimerOpType;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  Status = EFI_SUCCESS;

  if (!IsConfigUpdate) {
    //
    // If it's not a configuration update, increase the configured children number.
    //
    MnpServiceData->ConfiguredChildrenNumber++;

    if (MnpServiceData->ConfiguredChildrenNumber == 1) {
      //
      // It's the first configured child, start the simple network.
      //
      Status = MnpStartSnp (MnpServiceData->Snp);
      if (EFI_ERROR (Status)) {

        DEBUG ((EFI_D_ERROR, "MnpStart: MnpStartSnp failed, %r.\n", Status));
        goto ErrorExit;
      }

      //
      // Start the timeout timer.
      //
      Status = gBS->SetTimer (
                      MnpServiceData->TimeoutCheckTimer,
                      TimerPeriodic,
                      MNP_TIMEOUT_CHECK_INTERVAL
                      );
      if (EFI_ERROR (Status)) {

        DEBUG (
          (EFI_D_ERROR,
          "MnpStart, gBS->SetTimer for TimeoutCheckTimer %r.\n",
          Status)
          );
        goto ErrorExit;
      }
    }
  }

  if (MnpServiceData->EnableSystemPoll ^ EnableSystemPoll) {
    //
    // The EnableSystemPoll differs with the current state, disable or enable
    // the system poll.
    //
    TimerOpType = EnableSystemPoll ? TimerPeriodic : TimerCancel;

    Status      = gBS->SetTimer (MnpServiceData->PollTimer, TimerOpType, MNP_SYS_POLL_INTERVAL);
    if (EFI_ERROR (Status)) {

      DEBUG ((EFI_D_ERROR, "MnpStart: gBS->SetTimer for PollTimer failed, %r.\n", Status));
      goto ErrorExit;
    }

    MnpServiceData->EnableSystemPoll = EnableSystemPoll;
  }

  //
  // Change the receive filters if need.
  //
  Status = MnpConfigReceiveFilters (MnpServiceData);

ErrorExit:

  return Status;
}


/**
  Stop the managed network.

  @param  MnpServiceData        Pointer to the mnp service context data.

  @retval EFI_SUCCESS           The managed network is stopped.
  @retval Other                 Some error occurs.

**/
STATIC
EFI_STATUS
MnpStop (
  IN MNP_SERVICE_DATA  *MnpServiceData
  )
{
  EFI_STATUS  Status;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);
  ASSERT (MnpServiceData->ConfiguredChildrenNumber > 0);

  //
  // Configure the receive filters.
  //
  MnpConfigReceiveFilters (MnpServiceData);

  //
  // Decrease the children number.
  //
  MnpServiceData->ConfiguredChildrenNumber--;

  if (MnpServiceData->ConfiguredChildrenNumber > 0) {
    //
    // If there are other configured chilren, return and keep the timers and
    // simple network unchanged.
    //
    return EFI_SUCCESS;
  }

  //
  // No configured children now.
  //

  if (MnpServiceData->EnableSystemPoll) {
    //
    //  The system poll in on, cancel the poll timer.
    //
    Status  = gBS->SetTimer (MnpServiceData->PollTimer, TimerCancel, 0);
    MnpServiceData->EnableSystemPoll = FALSE;
  }

  //
  // Cancel the timeout timer.
  //
  Status  = gBS->SetTimer (MnpServiceData->TimeoutCheckTimer, TimerCancel, 0);

  //
  // Stop the simple network.
  //
  Status  = MnpStopSnp (MnpServiceData->Snp);

  return Status;
}


/**
  Flush the instance's received data.

  @param  Instance              Pointer to the mnp instance context data.

  @return None.

**/
VOID
MnpFlushRcvdDataQueue (
  IN MNP_INSTANCE_DATA  *Instance
  )
{
  EFI_TPL          OldTpl;
  MNP_RXDATA_WRAP *RxDataWrap;

  NET_CHECK_SIGNATURE (Instance, MNP_INSTANCE_DATA_SIGNATURE);

  OldTpl = gBS->RaiseTPL (TPL_NOTIFY);

  while (!IsListEmpty (&Instance->RcvdPacketQueue)) {
    //
    // Remove all the Wraps.
    //
    RxDataWrap = NET_LIST_HEAD (&Instance->RcvdPacketQueue, MNP_RXDATA_WRAP, WrapEntry);

    //
    // Recycle the RxDataWrap.
    //
    MnpRecycleRxData (NULL, (VOID *) RxDataWrap);
    Instance->RcvdPacketQueueSize--;
  }

  ASSERT (Instance->RcvdPacketQueueSize == 0);

  gBS->RestoreTPL (OldTpl);
}


/**
  Configure the Instance using ConfigData.

  @param  Instance              Pointer to the mnp instance context data.
  @param  ConfigData            Pointer to the configuration data used to configure
                                the isntance.

  @retval EFI_SUCCESS           The Instance is configured.
  @retval EFI_UNSUPPORTED       EnableReceiveTimestamps is on and the
                                implementation doesn't support it.
  @retval Other                 Some error occurs.

**/
EFI_STATUS
MnpConfigureInstance (
  IN MNP_INSTANCE_DATA                *Instance,
  IN EFI_MANAGED_NETWORK_CONFIG_DATA  *ConfigData OPTIONAL
  )
{
  EFI_STATUS                      Status;
  MNP_SERVICE_DATA                *MnpServiceData;
  EFI_MANAGED_NETWORK_CONFIG_DATA *OldConfigData;
  EFI_MANAGED_NETWORK_CONFIG_DATA *NewConfigData;
  BOOLEAN                         IsConfigUpdate;

  NET_CHECK_SIGNATURE (Instance, MNP_INSTANCE_DATA_SIGNATURE);

  if ((ConfigData != NULL) && ConfigData->EnableReceiveTimestamps) {
    //
    // Don't support timestamp.
    //
    return EFI_UNSUPPORTED;
  }

  Status          = EFI_SUCCESS;

  MnpServiceData  = Instance->MnpServiceData;
  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  IsConfigUpdate  = (BOOLEAN) ((Instance->Configured) && (ConfigData != NULL));

  OldConfigData   = &Instance->ConfigData;
  NewConfigData   = ConfigData;
  if (NewConfigData == NULL) {
    //
    // Restore back the default config data if a reset of this instance
    // is required.
    //
    NewConfigData = &mMnpDefaultConfigData;
  }

  //
  // Reset the instance's receive filter.
  //
  Instance->ReceiveFilter = 0;

  //
  // Clear the receive counters according to the old ConfigData.
  //
  if (OldConfigData->EnableUnicastReceive) {
    MnpServiceData->UnicastCount--;
  }

  if (OldConfigData->EnableMulticastReceive) {
    MnpServiceData->MulticastCount--;
  }

  if (OldConfigData->EnableBroadcastReceive) {
    MnpServiceData->BroadcastCount--;
  }

  if (OldConfigData->EnablePromiscuousReceive) {
    MnpServiceData->PromiscuousCount--;
  }

  //
  // Set the receive filter counters and the receive filter of the
  // instance according to the new ConfigData.
  //
  if (NewConfigData->EnableUnicastReceive) {
    MnpServiceData->UnicastCount++;
    Instance->ReceiveFilter |= MNP_RECEIVE_UNICAST;
  }

  if (NewConfigData->EnableMulticastReceive) {
    MnpServiceData->MulticastCount++;
  }

  if (NewConfigData->EnableBroadcastReceive) {
    MnpServiceData->BroadcastCount++;
    Instance->ReceiveFilter |= MNP_RECEIVE_BROADCAST;
  }

  if (NewConfigData->EnablePromiscuousReceive) {
    MnpServiceData->PromiscuousCount++;
  }

  if (OldConfigData->FlushQueuesOnReset) {

    MnpFlushRcvdDataQueue (Instance);
  }

  if (ConfigData == NULL) {

    Instance->ManagedNetwork.Cancel (&Instance->ManagedNetwork, NULL);
  }

  if (!NewConfigData->EnableMulticastReceive) {

    MnpGroupOp (Instance, FALSE, NULL, NULL);
  }

  //
  // Save the new configuration data.
  //
  CopyMem (OldConfigData, NewConfigData, sizeof (*OldConfigData));

  Instance->Configured  = (BOOLEAN) (ConfigData != NULL);

  if (Instance->Configured) {
    //
    // The instance is configured, start the Mnp.
    //
    Status = MnpStart (
              MnpServiceData,
              IsConfigUpdate,
              (BOOLEAN) !NewConfigData->DisableBackgroundPolling
              );
  } else {
    //
    // The instance is changed to the unconfigured state, stop the Mnp.
    //
    Status = MnpStop (MnpServiceData);
  }

  return Status;
}


/**
  Configure the Snp receive filters according to the instances' receive filter
  settings.

  @param  MnpServiceData        Pointer to the mnp service context data.

  @retval EFI_SUCCESS           The receive filters is configured.
  @retval EFI_OUT_OF_RESOURCES  The receive filters can't be configured due to lack
                                of memory resource.

**/
STATIC
EFI_STATUS
MnpConfigReceiveFilters (
  IN MNP_SERVICE_DATA  *MnpServiceData
  )
{
  EFI_STATUS                  Status;
  EFI_SIMPLE_NETWORK_PROTOCOL *Snp;
  EFI_MAC_ADDRESS             *MCastFilter;
  UINT32                      MCastFilterCnt;
  UINT32                      EnableFilterBits;
  UINT32                      DisableFilterBits;
  BOOLEAN                     ResetMCastFilters;
  LIST_ENTRY                  *Entry;
  UINT32                      Index;
  MNP_GROUP_ADDRESS           *GroupAddress;

  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  Snp = MnpServiceData->Snp;

  //
  // Initialize the enable filter and disable filter.
  //
  EnableFilterBits  = 0;
  DisableFilterBits = Snp->Mode->ReceiveFilterMask;

  if (MnpServiceData->UnicastCount != 0) {
    //
    // Enable unicast if any instance wants to receive unicast.
    //
    EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_UNICAST;
  }

  if (MnpServiceData->BroadcastCount != 0) {
    //
    // Enable broadcast if any instance wants to receive broadcast.
    //
    EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST;
  }

  MCastFilter       = NULL;
  MCastFilterCnt    = 0;
  ResetMCastFilters = TRUE;

  if ((MnpServiceData->MulticastCount != 0) && (MnpServiceData->GroupAddressCount != 0)) {
    //
    // There are instances configured to receive multicast and already some group
    // addresses are joined.
    //

    ResetMCastFilters = FALSE;

    if (MnpServiceData->GroupAddressCount <= Snp->Mode->MaxMCastFilterCount) {
      //
      // The joind group address is less than simple network's maximum count.
      // Just configure the snp to do the multicast filtering.
      //

      EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_MULTICAST;

      //
      // Allocate pool for the mulicast addresses.
      //
      MCastFilterCnt  = MnpServiceData->GroupAddressCount;
      MCastFilter     = AllocatePool (sizeof (EFI_MAC_ADDRESS) * MCastFilterCnt);
      if (MCastFilter == NULL) {

        DEBUG ((EFI_D_ERROR, "MnpConfigReceiveFilters: Failed to allocate memory resource for MCastFilter.\n"));
        return EFI_OUT_OF_RESOURCES;
      }

      //
      // Fill the multicast HW address buffer.
      //
      Index = 0;
      NET_LIST_FOR_EACH (Entry, &MnpServiceData->GroupAddressList) {

        GroupAddress            = NET_LIST_USER_STRUCT (Entry, MNP_GROUP_ADDRESS, AddrEntry);
        CopyMem (MCastFilter + Index, &GroupAddress->Address, sizeof (*(MCastFilter + Index)));
        Index++;

        ASSERT (Index <= MCastFilterCnt);
      }
    } else {
      //
      // The maximum multicast is reached, set the filter to be promiscuous
      // multicast.
      //

      if (Snp->Mode->ReceiveFilterMask & EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST) {
        EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;
      } else {
        //
        // Either MULTICAST or PROMISCUOUS_MULTICAST is not supported by Snp,
        // set the NIC to be promiscuous although this will tremendously degrade
        // the performance.
        //
        EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS;
      }
    }
  }

  if (MnpServiceData->PromiscuousCount != 0) {
    //
    // Enable promiscuous if any instance wants to receive promiscuous.
    //
    EnableFilterBits |= EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS;
  }

  //
  // Set the disable filter.
  //
  DisableFilterBits ^= EnableFilterBits;

  //
  // Configure the receive filters of SNP.
  //
  Status = Snp->ReceiveFilters (
                  Snp,
                  EnableFilterBits,
                  DisableFilterBits,
                  ResetMCastFilters,
                  MCastFilterCnt,
                  MCastFilter
                  );
  DEBUG_CODE (
    if (EFI_ERROR (Status)) {

    DEBUG (
      (EFI_D_ERROR,
      "MnpConfigReceiveFilters: Snp->ReceiveFilters failed, %r.\n",
      Status)
      );
  }
  );

  if (MCastFilter != NULL) {
    //
    // Free the buffer used to hold the group addresses.
    //
    gBS->FreePool (MCastFilter);
  }

  return Status;
}


/**
  Add a group address control block which controls the MacAddress for
  this instance.

  @param  Instance              Pointer to the mnp instance context data.
  @param  CtrlBlk               Pointer to the group address control block.
  @param  GroupAddress          Pointer to the group adress.
  @param  MacAddress            Pointer to the mac address.
  @param  HwAddressSize         The hardware address size.

  @retval EFI_SUCCESS           The group address control block is added.
  @retval EFI_OUT_OF_RESOURCE   Failed due to lack of memory resources.

**/
STATIC
EFI_STATUS
MnpGroupOpAddCtrlBlk (
  IN MNP_INSTANCE_DATA        *Instance,
  IN MNP_GROUP_CONTROL_BLOCK  *CtrlBlk,
  IN MNP_GROUP_ADDRESS        *GroupAddress OPTIONAL,
  IN EFI_MAC_ADDRESS          *MacAddress,
  IN UINT32                   HwAddressSize
  )
{
  MNP_SERVICE_DATA  *MnpServiceData;

  NET_CHECK_SIGNATURE (Instance, MNP_INSTANCE_DATA_SIGNATURE);

  MnpServiceData = Instance->MnpServiceData;
  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  if (GroupAddress == NULL) {

    ASSERT (MacAddress != NULL);

    //
    // Allocate a new GroupAddress to be added into MNP's GroupAddressList.
    //
    GroupAddress = AllocatePool (sizeof (MNP_GROUP_ADDRESS));
    if (GroupAddress == NULL) {

      DEBUG ((EFI_D_ERROR, "MnpGroupOpFormCtrlBlk: Failed to allocate memory resource.\n"));

      return EFI_OUT_OF_RESOURCES;
    }

    CopyMem (&GroupAddress->Address, MacAddress, sizeof (GroupAddress->Address));
    GroupAddress->RefCnt  = 0;
    InsertTailList (
      &MnpServiceData->GroupAddressList,
      &GroupAddress->AddrEntry
      );
    MnpServiceData->GroupAddressCount++;
  }

  //
  // Increase the RefCnt.
  //
  GroupAddress->RefCnt++;

  //
  // Add the CtrlBlk into the instance's GroupCtrlBlkList.
  //
  CtrlBlk->GroupAddress = GroupAddress;
  InsertTailList (&Instance->GroupCtrlBlkList, &CtrlBlk->CtrlBlkEntry);

  return EFI_SUCCESS;
}


/**
  Delete a group control block from the instance. If the controlled group address's
  reference count reaches zero, the group address is removed too.

  @param  Instance              Pointer to the instance context data.
  @param  CtrlBlk               Pointer to the group control block to delete.

  @return The group address controlled by the control block is no longer used or not.

**/
STATIC
BOOLEAN
MnpGroupOpDelCtrlBlk (
  IN MNP_INSTANCE_DATA        *Instance,
  IN MNP_GROUP_CONTROL_BLOCK  *CtrlBlk
  )
{
  MNP_SERVICE_DATA  *MnpServiceData;
  MNP_GROUP_ADDRESS *GroupAddress;

  NET_CHECK_SIGNATURE (Instance, MNP_INSTANCE_DATA_SIGNATURE);

  MnpServiceData = Instance->MnpServiceData;
  NET_CHECK_SIGNATURE (MnpServiceData, MNP_SERVICE_DATA_SIGNATURE);

  //
  // Remove and free the CtrlBlk.
  //
  GroupAddress = CtrlBlk->GroupAddress;
  RemoveEntryList (&CtrlBlk->CtrlBlkEntry);
  gBS->FreePool (CtrlBlk);

  ASSERT (GroupAddress->RefCnt > 0);

  //
  // Count down the RefCnt.
  //
  GroupAddress->RefCnt--;

  if (GroupAddress->RefCnt == 0) {
    //
    // Free this GroupAddress entry if no instance uses it.
    //
    MnpServiceData->GroupAddressCount--;
    RemoveEntryList (&GroupAddress->AddrEntry);
    gBS->FreePool (GroupAddress);

    return TRUE;
  }

  return FALSE;
}


/**
  Do the group operations for this instance.

  @param  Instance              Pointer to the instance context data.
  @param  JoinFlag              Set to TRUE to join a group. Set to TRUE to leave a
                                group/groups.
  @param  MacAddress            Pointer to the group address to join or leave.
  @param  CtrlBlk               Pointer to the group control block if JoinFlag if
                                FALSE.

  @retval EFI_SUCCESS           The group operation finished.
  @retval Other                 Some error occurs.

**/
EFI_STATUS
MnpGroupOp (
  IN MNP_INSTANCE_DATA        *Instance,
  IN BOOLEAN                  JoinFlag,
  IN EFI_MAC_ADDRESS          *MacAddress OPTIONAL,
  IN MNP_GROUP_CONTROL_BLOCK  *CtrlBlk OPTIONAL
  )
{
  MNP_SERVICE_DATA        *MnpServiceData;
  LIST_ENTRY              *Entry;
  LIST_ENTRY              *NextEntry;
  MNP_GROUP_ADDRESS       *GroupAddress;
  EFI_SIMPLE_NETWORK_MODE *SnpMode;
  MNP_GROUP_CONTROL_BLOCK *NewCtrlBlk;
  EFI_STATUS              Status;
  BOOLEAN                 AddressExist;
  BOOLEAN                 NeedUpdate;

  NET_CHECK_SIGNATURE (Instance, MNP_INSTANCE_DATA_SIGNATURE);

  MnpServiceData  = Instance->MnpServiceData;
  SnpMode         = MnpServiceData->Snp->Mode;

  if (JoinFlag) {
    //
    // A new gropu address is to be added.
    //

    GroupAddress  = NULL;
    AddressExist  = FALSE;

    //
    // Allocate memory for the control block.
    //
    NewCtrlBlk    = AllocatePool (sizeof (MNP_GROUP_CONTROL_BLOCK));
    if (NewCtrlBlk == NULL) {

      DEBUG ((EFI_D_ERROR, "MnpGroupOp: Failed to allocate memory resource.\n"));
      return EFI_OUT_OF_RESOURCES;
    }

    NET_LIST_FOR_EACH (Entry, &MnpServiceData->GroupAddressList) {
      //
      // Check whether the MacAddress is already joined by other instances.
      //
      GroupAddress = NET_LIST_USER_STRUCT (Entry, MNP_GROUP_ADDRESS, AddrEntry);
      if (0 == CompareMem (
                MacAddress,
                &GroupAddress->Address,
                SnpMode->HwAddressSize
                )) {

        AddressExist = TRUE;
        break;
      }
    }

    if (!AddressExist) {
      GroupAddress = NULL;
    }

    //
    // Add the GroupAddress for this instance.
    //
    Status = MnpGroupOpAddCtrlBlk (
              Instance,
              NewCtrlBlk,
              GroupAddress,
              MacAddress,
              SnpMode->HwAddressSize
              );
    if (EFI_ERROR (Status)) {

      return Status;
    }

    NeedUpdate = TRUE;
  } else {

    if (MacAddress != NULL) {

      ASSERT (CtrlBlk != NULL);

      //
      // Leave the specific multicast mac address.
      //
      NeedUpdate = MnpGroupOpDelCtrlBlk (Instance, CtrlBlk);
    } else {
      //
      // Leave all multicast mac addresses.
      //
      NeedUpdate = FALSE;

      NET_LIST_FOR_EACH_SAFE (Entry, NextEntry, &Instance->GroupCtrlBlkList) {

        NewCtrlBlk = NET_LIST_USER_STRUCT (
                      Entry,
                      MNP_GROUP_CONTROL_BLOCK,
                      CtrlBlkEntry
                      );
        //
        // Update is required if the group address left is no longer used
        // by other instances.
        //
        NeedUpdate = MnpGroupOpDelCtrlBlk (Instance, NewCtrlBlk);
      }
    }
  }

  Status = EFI_SUCCESS;

  if (NeedUpdate) {
    //
    // Reconfigure the receive filters if necessary.
    //
    Status = MnpConfigReceiveFilters (MnpServiceData);
  }

  return Status;
}