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 - 2013, Intel Corporation. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <Library/BaseLib.h>
  13 #include <Library/BaseMemoryLib.h>
  14 #include <Library/UefiBootServicesTableLib.h>
  15
  16 #include "VirtioNet.h"
  17
  18 /**
  19   Receives a packet from a network interface.
  20
  21   @param  This       The protocol instance pointer.
  22   @param  HeaderSize The size, in bytes, of the media header received on the
  23                      network interface. If this parameter is NULL, then the
  24                      media header size will not be returned.
  25   @param  BufferSize On entry, the size, in bytes, of Buffer. On exit, the
  26                      size, in bytes, of the packet that was received on the
  27                      network interface.
  28   @param  Buffer     A pointer to the data buffer to receive both the media
  29                      header and the data.
  30   @param  SrcAddr    The source HW MAC address. If this parameter is NULL, the
  31                      HW MAC source address will not be extracted from the media
  32                      header.
  33   @param  DestAddr   The destination HW MAC address. If this parameter is NULL,
  34                      the HW MAC destination address will not be extracted from
  35                      the media header.
  36   @param  Protocol   The media header type. If this parameter is NULL, then the
  37                      protocol will not be extracted from the media header. See
  38                      RFC 1700 section "Ether Types" for examples.
  39
  40   @retval  EFI_SUCCESS           The received data was stored in Buffer, and
  41                                  BufferSize has been updated to the number of
  42                                  bytes received.
  43   @retval  EFI_NOT_STARTED       The network interface has not been started.
  44   @retval  EFI_NOT_READY         The network interface is too busy to accept
  45                                  this transmit request.
  46   @retval  EFI_BUFFER_TOO_SMALL  The BufferSize parameter is too small.
  47   @retval  EFI_INVALID_PARAMETER One or more of the parameters has an
  48                                  unsupported value.
  49   @retval  EFI_DEVICE_ERROR      The command could not be sent to the network
  50                                  interface.
  51   @retval  EFI_UNSUPPORTED       This function is not supported by the network
  52                                  interface.
  53
  54 **/
  55 EFI_STATUS
  56 EFIAPI
  57 VirtioNetReceive (
  58   IN EFI_SIMPLE_NETWORK_PROTOCOL  *This,
  59   OUT UINTN                       *HeaderSize OPTIONAL,
  60   IN OUT UINTN                    *BufferSize,
  61   OUT VOID                        *Buffer,
  62   OUT EFI_MAC_ADDRESS             *SrcAddr    OPTIONAL,
  63   OUT EFI_MAC_ADDRESS             *DestAddr   OPTIONAL,
  64   OUT UINT16                      *Protocol   OPTIONAL
  65   )
  66 {
  67   VNET_DEV    *Dev;
  68   EFI_TPL     OldTpl;
  69   EFI_STATUS  Status;
  70   UINT16      RxCurUsed;
  71   UINT16      UsedElemIdx;
  72   UINT32      DescIdx;
  73   UINT32      RxLen;
  74   UINTN       OrigBufferSize;
  75   UINT8       *RxPtr;
  76   UINT16      AvailIdx;
  77   EFI_STATUS  NotifyStatus;
  78   UINTN       RxBufOffset;
  79
  80   if ((This == NULL) || (BufferSize == NULL) || (Buffer == NULL)) {
  81     return EFI_INVALID_PARAMETER;
  82   }
  83
  84   Dev    = VIRTIO_NET_FROM_SNP (This);
  85   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  86   switch (Dev->Snm.State) {
  87     case EfiSimpleNetworkStopped:
  88       Status = EFI_NOT_STARTED;
  89       goto Exit;
  90     case EfiSimpleNetworkStarted:
  91       Status = EFI_DEVICE_ERROR;
  92       goto Exit;
  93     default:
  94       break;
  95   }
  96
  97   //
  98   // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
  99   //
 100   MemoryFence ();
 101   RxCurUsed = *Dev->RxRing.Used.Idx;
 102   MemoryFence ();
 103
 104   if (Dev->RxLastUsed == RxCurUsed) {
 105     Status = EFI_NOT_READY;
 106     goto Exit;
 107   }
 108
 109   UsedElemIdx = Dev->RxLastUsed % Dev->RxRing.QueueSize;
 110   DescIdx     = Dev->RxRing.Used.UsedElem[UsedElemIdx].Id;
 111   RxLen       = Dev->RxRing.Used.UsedElem[UsedElemIdx].Len;
 112
 113   //
 114   // the virtio-net request header must be complete; we skip it
 115   //
 116   ASSERT (RxLen >= Dev->RxRing.Desc[DescIdx].Len);
 117   RxLen -= Dev->RxRing.Desc[DescIdx].Len;
 118   //
 119   // the host must not have filled in more data than requested
 120   //
 121   ASSERT (RxLen <= Dev->RxRing.Desc[DescIdx + 1].Len);
 122
 123   OrigBufferSize = *BufferSize;
 124   *BufferSize    = RxLen;
 125
 126   if (OrigBufferSize < RxLen) {
 127     Status = EFI_BUFFER_TOO_SMALL;
 128     goto Exit; // keep the packet
 129   }
 130
 131   if (RxLen < Dev->Snm.MediaHeaderSize) {
 132     Status = EFI_DEVICE_ERROR;
 133     goto RecycleDesc; // drop useless short packet
 134   }
 135
 136   if (HeaderSize != NULL) {
 137     *HeaderSize = Dev->Snm.MediaHeaderSize;
 138   }
 139
 140   RxBufOffset = (UINTN)(Dev->RxRing.Desc[DescIdx + 1].Addr -
 141                         Dev->RxBufDeviceBase);
 142   RxPtr = Dev->RxBuf + RxBufOffset;
 143   CopyMem (Buffer, RxPtr, RxLen);
 144
 145   if (DestAddr != NULL) {
 146     CopyMem (DestAddr, RxPtr, SIZE_OF_VNET (Mac));
 147   }
 148
 149   RxPtr += SIZE_OF_VNET (Mac);
 150
 151   if (SrcAddr != NULL) {
 152     CopyMem (SrcAddr, RxPtr, SIZE_OF_VNET (Mac));
 153   }
 154
 155   RxPtr += SIZE_OF_VNET (Mac);
 156
 157   if (Protocol != NULL) {
 158     *Protocol = (UINT16)((RxPtr[0] << 8) | RxPtr[1]);
 159   }
 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 = Dev->VirtIo->SetQueueNotify (Dev->VirtIo, VIRTIO_NET_Q_RX);
 180   if (!EFI_ERROR (Status)) {
 181     // earlier error takes precedence
 182     Status = NotifyStatus;
 183   }
 184
 185 Exit:
 186   gBS->RestoreTPL (OldTpl);
 187   return Status;
 188 }