OvmfPkg/VirtioNetDxe/SnpReceive.c

   1 /** @file
   2
   3   Implementation of the SNP.Receive() function and its private helpers if any.
   4
   5   Copyright (C) 2013, Red Hat, Inc.
   6   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   7
   8   This program and the accompanying materials are licensed and made available
   9   under the terms and conditions of the BSD License which accompanies this
  10   distribution. The full text of the license may be found at
  11   http://opensource.org/licenses/bsd-license.php
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  14   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17
  18 #include <Library/BaseLib.h>
  19 #include <Library/BaseMemoryLib.h>
  20 #include <Library/UefiBootServicesTableLib.h>
  21
  22 #include "VirtioNet.h"
  23
  24 /**
  25   Receives a packet from a network interface.
  26
  27   @param  This       The protocol instance pointer.
  28   @param  HeaderSize The size, in bytes, of the media header received on the
  29                      network interface. If this parameter is NULL, then the
  30                      media header size will not be returned.
  31   @param  BufferSize On entry, the size, in bytes, of Buffer. On exit, the
  32                      size, in bytes, of the packet that was received on the
  33                      network interface.
  34   @param  Buffer     A pointer to the data buffer to receive both the media
  35                      header and the data.
  36   @param  SrcAddr    The source HW MAC address. If this parameter is NULL, the
  37                      HW MAC source address will not be extracted from the media
  38                      header.
  39   @param  DestAddr   The destination HW MAC address. If this parameter is NULL,
  40                      the HW MAC destination address will not be extracted from
  41                      the media header.
  42   @param  Protocol   The media header type. If this parameter is NULL, then the
  43                      protocol will not be extracted from the media header. See
  44                      RFC 1700 section "Ether Types" for examples.
  45
  46   @retval  EFI_SUCCESS           The received data was stored in Buffer, and
  47                                  BufferSize has been updated to the number of
  48                                  bytes received.
  49   @retval  EFI_NOT_STARTED       The network interface has not been started.
  50   @retval  EFI_NOT_READY         The network interface is too busy to accept
  51                                  this transmit request.
  52   @retval  EFI_BUFFER_TOO_SMALL  The BufferSize parameter is too small.
  53   @retval  EFI_INVALID_PARAMETER One or more of the parameters has an
  54                                  unsupported value.
  55   @retval  EFI_DEVICE_ERROR      The command could not be sent to the network
  56                                  interface.
  57   @retval  EFI_UNSUPPORTED       This function is not supported by the network
  58                                  interface.
  59
  60 **/
  61
  62 EFI_STATUS
  63 EFIAPI
  64 VirtioNetReceive (
  65   IN EFI_SIMPLE_NETWORK_PROTOCOL *This,
  66   OUT UINTN                      *HeaderSize OPTIONAL,
  67   IN OUT UINTN                   *BufferSize,
  68   OUT VOID                       *Buffer,
  69   OUT EFI_MAC_ADDRESS            *SrcAddr    OPTIONAL,
  70   OUT EFI_MAC_ADDRESS            *DestAddr   OPTIONAL,
  71   OUT UINT16                     *Protocol   OPTIONAL
  72   )
  73 {
  74   VNET_DEV   *Dev;
  75   EFI_TPL    OldTpl;
  76   EFI_STATUS Status;
  77   UINT16     RxCurUsed;
  78   UINT16     UsedElemIdx;
  79   UINT32     DescIdx;
  80   UINT32     RxLen;
  81   UINTN      OrigBufferSize;
  82   UINT8      *RxPtr;
  83   UINT16     AvailIdx;
  84   EFI_STATUS NotifyStatus;
  85
  86   if (This == NULL || BufferSize == NULL || Buffer == NULL) {
  87     return EFI_INVALID_PARAMETER;
  88   }
  89
  90   Dev = VIRTIO_NET_FROM_SNP (This);
  91   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  92   switch (Dev->Snm.State) {
  93   case EfiSimpleNetworkStopped:
  94     Status = EFI_NOT_STARTED;
  95     goto Exit;
  96   case EfiSimpleNetworkStarted:
  97     Status = EFI_DEVICE_ERROR;
  98     goto Exit;
  99   default:
 100     break;
 101   }
 102
 103   //
 104   // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
 105   //
 106   MemoryFence ();
 107   RxCurUsed = *Dev->RxRing.Used.Idx;
 108
 109   if (Dev->RxLastUsed == RxCurUsed) {
 110     Status = EFI_NOT_READY;
 111     goto Exit;
 112   }
 113
 114   UsedElemIdx = Dev->RxLastUsed % Dev->RxRing.QueueSize;
 115   DescIdx = Dev->RxRing.Used.UsedElem[UsedElemIdx].Id;
 116   RxLen   = Dev->RxRing.Used.UsedElem[UsedElemIdx].Len;
 117
 118   //
 119   // the virtio-net request header must be complete; we skip it
 120   //
 121   ASSERT (RxLen >= Dev->RxRing.Desc[DescIdx].Len);
 122   RxLen -= Dev->RxRing.Desc[DescIdx].Len;
 123   //
 124   // the host must not have filled in more data than requested
 125   //
 126   ASSERT (RxLen <= Dev->RxRing.Desc[DescIdx + 1].Len);
 127
 128   OrigBufferSize = *BufferSize;
 129   *BufferSize = RxLen;
 130
 131   if (OrigBufferSize < RxLen) {
 132     Status = EFI_BUFFER_TOO_SMALL;
 133     goto Exit; // keep the packet
 134   }
 135
 136   if (RxLen < Dev->Snm.MediaHeaderSize) {
 137     Status = EFI_DEVICE_ERROR;
 138     goto RecycleDesc; // drop useless short packet
 139   }
 140
 141   if (HeaderSize != NULL) {
 142     *HeaderSize = Dev->Snm.MediaHeaderSize;
 143   }
 144
 145   RxPtr = (UINT8 *)Dev->RxRing.Desc[DescIdx + 1].Addr;
 146   CopyMem (Buffer, RxPtr, RxLen);
 147
 148   if (DestAddr != NULL) {
 149     CopyMem (DestAddr, RxPtr, SIZE_OF_VNET (VhdrMac));
 150   }
 151   RxPtr += SIZE_OF_VNET (VhdrMac);
 152
 153   if (SrcAddr != NULL) {
 154     CopyMem (SrcAddr, RxPtr, SIZE_OF_VNET (VhdrMac));
 155   }
 156   RxPtr += SIZE_OF_VNET (VhdrMac);
 157
 158   if (Protocol != NULL) {
 159     *Protocol = (UINT16) ((RxPtr[0] << 8) | RxPtr[1]);
 160   }
 161   RxPtr += sizeof (UINT16);
 162
 163   Status = EFI_SUCCESS;
 164
 165 RecycleDesc:
 166   ++Dev->RxLastUsed;
 167
 168   //
 169   // virtio-0.9.5, 2.4.1 Supplying Buffers to The Device
 170   //
 171   AvailIdx = *Dev->RxRing.Avail.Idx;
 172   Dev->RxRing.Avail.Ring[AvailIdx++ % Dev->RxRing.QueueSize] =
 173     (UINT16) DescIdx;
 174
 175   MemoryFence ();
 176   *Dev->RxRing.Avail.Idx = AvailIdx;
 177
 178   MemoryFence ();
 179   NotifyStatus = VIRTIO_CFG_WRITE (Dev, Generic.VhdrQueueNotify,
 180                    VIRTIO_NET_Q_RX);
 181
 182   if (!EFI_ERROR (Status)) { // earlier error takes precedence
 183     Status = NotifyStatus;
 184   }
 185
 186 Exit:
 187   gBS->RestoreTPL (OldTpl);
 188   return Status;
 189 }