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
  56 EFI_STATUS
  57 EFIAPI
  58 VirtioNetReceive (
  59   IN EFI_SIMPLE_NETWORK_PROTOCOL *This,
  60   OUT UINTN                      *HeaderSize OPTIONAL,
  61   IN OUT UINTN                   *BufferSize,
  62   OUT VOID                       *Buffer,
  63   OUT EFI_MAC_ADDRESS            *SrcAddr    OPTIONAL,
  64   OUT EFI_MAC_ADDRESS            *DestAddr   OPTIONAL,
  65   OUT UINT16                     *Protocol   OPTIONAL
  66   )
  67 {
  68   VNET_DEV   *Dev;
  69   EFI_TPL    OldTpl;
  70   EFI_STATUS Status;
  71   UINT16     RxCurUsed;
  72   UINT16     UsedElemIdx;
  73   UINT32     DescIdx;
  74   UINT32     RxLen;
  75   UINTN      OrigBufferSize;
  76   UINT8      *RxPtr;
  77   UINT16     AvailIdx;
  78   EFI_STATUS NotifyStatus;
  79   UINTN      RxBufOffset;
  80
  81   if (This == NULL || BufferSize == NULL || Buffer == NULL) {
  82     return EFI_INVALID_PARAMETER;
  83   }
  84
  85   Dev = VIRTIO_NET_FROM_SNP (This);
  86   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  87   switch (Dev->Snm.State) {
  88   case EfiSimpleNetworkStopped:
  89     Status = EFI_NOT_STARTED;
  90     goto Exit;
  91   case EfiSimpleNetworkStarted:
  92     Status = EFI_DEVICE_ERROR;
  93     goto Exit;
  94   default:
  95     break;
  96   }
  97
  98   //
  99   // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device
 100   //
 101   MemoryFence ();
 102   RxCurUsed = *Dev->RxRing.Used.Idx;
 103   MemoryFence ();
 104
 105   if (Dev->RxLastUsed == RxCurUsed) {
 106     Status = EFI_NOT_READY;
 107     goto Exit;
 108   }
 109
 110   UsedElemIdx = Dev->RxLastUsed % Dev->RxRing.QueueSize;
 111   DescIdx = Dev->RxRing.Used.UsedElem[UsedElemIdx].Id;
 112   RxLen   = Dev->RxRing.Used.UsedElem[UsedElemIdx].Len;
 113
 114   //
 115   // the virtio-net request header must be complete; we skip it
 116   //
 117   ASSERT (RxLen >= Dev->RxRing.Desc[DescIdx].Len);
 118   RxLen -= Dev->RxRing.Desc[DescIdx].Len;
 119   //
 120   // the host must not have filled in more data than requested
 121   //
 122   ASSERT (RxLen <= Dev->RxRing.Desc[DescIdx + 1].Len);
 123
 124   OrigBufferSize = *BufferSize;
 125   *BufferSize = RxLen;
 126
 127   if (OrigBufferSize < RxLen) {
 128     Status = EFI_BUFFER_TOO_SMALL;
 129     goto Exit; // keep the packet
 130   }
 131
 132   if (RxLen < Dev->Snm.MediaHeaderSize) {
 133     Status = EFI_DEVICE_ERROR;
 134     goto RecycleDesc; // drop useless short packet
 135   }
 136
 137   if (HeaderSize != NULL) {
 138     *HeaderSize = Dev->Snm.MediaHeaderSize;
 139   }
 140
 141   RxBufOffset = (UINTN)(Dev->RxRing.Desc[DescIdx + 1].Addr -
 142                         Dev->RxBufDeviceBase);
 143   RxPtr = Dev->RxBuf + RxBufOffset;
 144   CopyMem (Buffer, RxPtr, RxLen);
 145
 146   if (DestAddr != NULL) {
 147     CopyMem (DestAddr, RxPtr, SIZE_OF_VNET (Mac));
 148   }
 149   RxPtr += SIZE_OF_VNET (Mac);
 150
 151   if (SrcAddr != NULL) {
 152     CopyMem (SrcAddr, RxPtr, SIZE_OF_VNET (Mac));
 153   }
 154   RxPtr += SIZE_OF_VNET (Mac);
 155
 156   if (Protocol != NULL) {
 157     *Protocol = (UINT16) ((RxPtr[0] << 8) | RxPtr[1]);
 158   }
 159   RxPtr += sizeof (UINT16);
 160
 161   Status = EFI_SUCCESS;
 162
 163 RecycleDesc:
 164   ++Dev->RxLastUsed;
 165
 166   //
 167   // virtio-0.9.5, 2.4.1 Supplying Buffers to The Device
 168   //
 169   AvailIdx = *Dev->RxRing.Avail.Idx;
 170   Dev->RxRing.Avail.Ring[AvailIdx++ % Dev->RxRing.QueueSize] =
 171     (UINT16) DescIdx;
 172
 173   MemoryFence ();
 174   *Dev->RxRing.Avail.Idx = AvailIdx;
 175
 176   MemoryFence ();
 177   NotifyStatus = Dev->VirtIo->SetQueueNotify (Dev->VirtIo, VIRTIO_NET_Q_RX);
 178   if (!EFI_ERROR (Status)) { // earlier error takes precedence
 179     Status = NotifyStatus;
 180   }
 181
 182 Exit:
 183   gBS->RestoreTPL (OldTpl);
 184   return Status;
 185 }