OvmfPkg/VirtioNetDxe/SnpReceiveFilters.c

/** @file

  Implementation of the SNP.ReceiveFilters() function and its private helpers
  if any.

  Copyright (C) 2013, Red Hat, Inc.
  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Library/UefiBootServicesTableLib.h>

#include "VirtioNet.h"

/**
  Manages the multicast receive filters of a network interface.

  @param  This             The protocol instance pointer.
  @param  Enable           A bit mask of receive filters to enable on the
                           network interface.
  @param  Disable          A bit mask of receive filters to disable on the
                           network interface.
  @param  ResetMCastFilter Set to TRUE to reset the contents of the multicast
                           receive filters on the network interface to their
                           default values.
  @param  McastFilterCnt   Number of multicast HW MAC addresses in the new
                           MCastFilter list. This value must be less than or
                           equal to the MCastFilterCnt field of
                           EFI_SIMPLE_NETWORK_MODE. This field is optional if
                           ResetMCastFilter is TRUE.
  @param  MCastFilter      A pointer to a list of new multicast receive filter
                           HW MAC addresses. This list will replace any
                           existing multicast HW MAC address list. This field
                           is optional if ResetMCastFilter is TRUE.

  @retval EFI_SUCCESS           The multicast receive filter list was updated.
  @retval EFI_NOT_STARTED       The network interface has not been started.
  @retval EFI_INVALID_PARAMETER One or more of the parameters has an
                                unsupported value.
  @retval EFI_DEVICE_ERROR      The command could not be sent to the network
                                interface.
  @retval EFI_UNSUPPORTED       This function is not supported by the network
                                interface.

**/
EFI_STATUS
EFIAPI
VirtioNetReceiveFilters (
  IN EFI_SIMPLE_NETWORK_PROTOCOL  *This,
  IN UINT32                       Enable,
  IN UINT32                       Disable,
  IN BOOLEAN                      ResetMCastFilter,
  IN UINTN                        MCastFilterCnt    OPTIONAL,
  IN EFI_MAC_ADDRESS              *MCastFilter      OPTIONAL
  )
{
  VNET_DEV    *Dev;
  EFI_TPL     OldTpl;
  EFI_STATUS  Status;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Dev    = VIRTIO_NET_FROM_SNP (This);
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  switch (Dev->Snm.State) {
    case EfiSimpleNetworkStopped:
      Status = EFI_NOT_STARTED;
      goto Exit;
    case EfiSimpleNetworkStarted:
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    default:
      break;
  }

  //
  // MNP apparently fails to initialize on top of us if we simply return
  // EFI_UNSUPPORTED in this function.
  //
  // Hence we openly refuse multicast functionality, and fake the rest by
  // selecting a no stricter filter setting than whatever is requested. The
  // UEFI-2.3.1+errC spec allows this. In practice we don't change our current
  // (default) filter. Additionally, receiving software is responsible for
  // discarding any packets getting through the filter.
  //
  Status = (
            ((Enable | Disable) & ~Dev->Snm.ReceiveFilterMask) != 0 ||
            (!ResetMCastFilter && MCastFilterCnt > Dev->Snm.MaxMCastFilterCount)
            ) ? EFI_INVALID_PARAMETER : EFI_SUCCESS;

Exit:
  gBS->RestoreTPL (OldTpl);
  return Status;
}