OvmfPkg/VirtioNetDxe/SnpMcastIpToMac.c

   1 /** @file
   2
   3   Implementation of the SNP.McastIpToMac() function and its private helpers if
   4   any.
   5
   6   Copyright (C) 2013, Red Hat, Inc.
   7   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   8
   9   SPDX-License-Identifier: BSD-2-Clause-Patent
  10
  11 **/
  12
  13 #include <Library/UefiBootServicesTableLib.h>
  14
  15 #include "VirtioNet.h"
  16
  17 /**
  18   Converts a multicast IP address to a multicast HW MAC address.
  19
  20   @param  This The protocol instance pointer.
  21   @param  IPv6 Set to TRUE if the multicast IP address is IPv6 [RFC 2460]. Set
  22                to FALSE if the multicast IP address is IPv4 [RFC 791].
  23   @param  IP   The multicast IP address that is to be converted to a multicast
  24                HW MAC address.
  25   @param  MAC  The multicast HW MAC address that is to be generated from IP.
  26
  27   @retval EFI_SUCCESS           The multicast IP address was mapped to the
  28                                 multicast HW MAC address.
  29   @retval EFI_NOT_STARTED       The network interface has not been started.
  30   @retval EFI_BUFFER_TOO_SMALL  The Statistics buffer was too small. The
  31                                 current buffer size needed to hold the
  32                                 statistics is returned in StatisticsSize.
  33   @retval EFI_INVALID_PARAMETER One or more of the parameters has an
  34                                 unsupported value.
  35   @retval EFI_DEVICE_ERROR      The command could not be sent to the network
  36                                 interface.
  37   @retval EFI_UNSUPPORTED       This function is not supported by the network
  38                                 interface.
  39
  40 **/
  41 EFI_STATUS
  42 EFIAPI
  43 VirtioNetMcastIpToMac (
  44   IN EFI_SIMPLE_NETWORK_PROTOCOL  *This,
  45   IN BOOLEAN                      IPv6,
  46   IN EFI_IP_ADDRESS               *Ip,
  47   OUT EFI_MAC_ADDRESS             *Mac
  48   )
  49 {
  50   VNET_DEV    *Dev;
  51   EFI_TPL     OldTpl;
  52   EFI_STATUS  Status;
  53
  54   //
  55   // http://en.wikipedia.org/wiki/Multicast_address
  56   //
  57   if ((This == NULL) || (Ip == NULL) || (Mac == NULL) ||
  58       (IPv6 && ((Ip->v6.Addr[0]) != 0xFF)) ||       // invalid IPv6 mcast addr
  59       (!IPv6 && ((Ip->v4.Addr[0] & 0xF0) != 0xE0))  // invalid IPv4 mcast addr
  60       )
  61   {
  62     return EFI_INVALID_PARAMETER;
  63   }
  64
  65   Dev    = VIRTIO_NET_FROM_SNP (This);
  66   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  67   switch (Dev->Snm.State) {
  68     case EfiSimpleNetworkStopped:
  69       Status = EFI_NOT_STARTED;
  70       goto Exit;
  71     case EfiSimpleNetworkStarted:
  72       Status = EFI_DEVICE_ERROR;
  73       goto Exit;
  74     default:
  75       break;
  76   }
  77
  78   //
  79   // http://en.wikipedia.org/wiki/IP_multicast#Layer_2_delivery
  80   //
  81   if (IPv6) {
  82     Mac->Addr[0] = 0x33;
  83     Mac->Addr[1] = 0x33;
  84     Mac->Addr[2] = Ip->v6.Addr[12];
  85     Mac->Addr[3] = Ip->v6.Addr[13];
  86     Mac->Addr[4] = Ip->v6.Addr[14];
  87     Mac->Addr[5] = Ip->v6.Addr[15];
  88   } else {
  89     Mac->Addr[0] = 0x01;
  90     Mac->Addr[1] = 0x00;
  91     Mac->Addr[2] = 0x5E;
  92     Mac->Addr[3] = Ip->v4.Addr[1] & 0x7F;
  93     Mac->Addr[4] = Ip->v4.Addr[2];
  94     Mac->Addr[5] = Ip->v4.Addr[3];
  95   }
  96
  97   Status = EFI_SUCCESS;
  98
  99 Exit:
 100   gBS->RestoreTPL (OldTpl);
 101   return Status;
 102 }