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 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
VirtioNetReceive(IN EFI_SIMPLE_NETWORK_PROTOCOL * This,OUT UINTN * HeaderSize OPTIONAL,IN OUT UINTN * BufferSize,OUT VOID * Buffer,OUT EFI_MAC_ADDRESS * SrcAddr OPTIONAL,OUT EFI_MAC_ADDRESS * DestAddr OPTIONAL,OUT UINT16 * Protocol OPTIONAL)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 MemoryFence ();
109
110 if (Dev->RxLastUsed == RxCurUsed) {
111 Status = EFI_NOT_READY;
112 goto Exit;
113 }
114
115 UsedElemIdx = Dev->RxLastUsed % Dev->RxRing.QueueSize;
116 DescIdx = Dev->RxRing.Used.UsedElem[UsedElemIdx].Id;
117 RxLen = Dev->RxRing.Used.UsedElem[UsedElemIdx].Len;
118
119 //
120 // the virtio-net request header must be complete; we skip it
121 //
122 ASSERT (RxLen >= Dev->RxRing.Desc[DescIdx].Len);
123 RxLen -= Dev->RxRing.Desc[DescIdx].Len;
124 //
125 // the host must not have filled in more data than requested
126 //
127 ASSERT (RxLen <= Dev->RxRing.Desc[DescIdx + 1].Len);
128
129 OrigBufferSize = *BufferSize;
130 *BufferSize = RxLen;
131
132 if (OrigBufferSize < RxLen) {
133 Status = EFI_BUFFER_TOO_SMALL;
134 goto Exit; // keep the packet
135 }
136
137 if (RxLen < Dev->Snm.MediaHeaderSize) {
138 Status = EFI_DEVICE_ERROR;
139 goto RecycleDesc; // drop useless short packet
140 }
141
142 if (HeaderSize != NULL) {
143 *HeaderSize = Dev->Snm.MediaHeaderSize;
144 }
145
146 RxPtr = (UINT8 *)(UINTN) Dev->RxRing.Desc[DescIdx + 1].Addr;
147 CopyMem (Buffer, RxPtr, RxLen);
148
149 if (DestAddr != NULL) {
150 CopyMem (DestAddr, RxPtr, SIZE_OF_VNET (Mac));
151 }
152 RxPtr += SIZE_OF_VNET (Mac);
153
154 if (SrcAddr != NULL) {
155 CopyMem (SrcAddr, RxPtr, SIZE_OF_VNET (Mac));
156 }
157 RxPtr += SIZE_OF_VNET (Mac);
158
159 if (Protocol != NULL) {
160 *Protocol = (UINT16) ((RxPtr[0] << 8) | RxPtr[1]);
161 }
162 RxPtr += sizeof (UINT16);
163
164 Status = EFI_SUCCESS;
165
166 RecycleDesc:
167 ++Dev->RxLastUsed;
168
169 //
170 // virtio-0.9.5, 2.4.1 Supplying Buffers to The Device
171 //
172 AvailIdx = *Dev->RxRing.Avail.Idx;
173 Dev->RxRing.Avail.Ring[AvailIdx++ % Dev->RxRing.QueueSize] =
174 (UINT16) DescIdx;
175
176 MemoryFence ();
177 *Dev->RxRing.Avail.Idx = AvailIdx;
178
179 MemoryFence ();
180 NotifyStatus = Dev->VirtIo->SetQueueNotify (Dev->VirtIo, VIRTIO_NET_Q_RX);
181 if (!EFI_ERROR (Status)) { // earlier error takes precedence
182 Status = NotifyStatus;
183 }
184
185 Exit:
186 gBS->RestoreTPL (OldTpl);
187 return Status;
188 }
189