1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "MtpRequestPacket"
18 
19 #include <stdio.h>
20 #include <sys/types.h>
21 #include <fcntl.h>
22 
23 #include "MtpRequestPacket.h"
24 
25 #include <usbhost/usbhost.h>
26 
27 namespace android {
28 
MtpRequestPacket()29 MtpRequestPacket::MtpRequestPacket()
30     :   MtpPacket(512),
31         mParameterCount(0)
32 {
33 }
34 
~MtpRequestPacket()35 MtpRequestPacket::~MtpRequestPacket() {
36 }
37 
38 #ifdef MTP_DEVICE
read(int fd)39 int MtpRequestPacket::read(int fd) {
40     int ret = ::read(fd, mBuffer, mBufferSize);
41     if (ret < 0) {
42         // file read error
43         return ret;
44     }
45 
46     // request packet should have 12 byte header followed by 0 to 5 32-bit arguments
47     const size_t read_size = static_cast<size_t>(ret);
48     if (read_size >= MTP_CONTAINER_HEADER_SIZE
49             && read_size <= MTP_CONTAINER_HEADER_SIZE + 5 * sizeof(uint32_t)
50             && ((read_size - MTP_CONTAINER_HEADER_SIZE) & 3) == 0) {
51         mPacketSize = read_size;
52         mParameterCount = (read_size - MTP_CONTAINER_HEADER_SIZE) / sizeof(uint32_t);
53     } else {
54         ALOGE("Malformed MTP request packet");
55         ret = -1;
56     }
57     return ret;
58 }
59 #endif
60 
61 #ifdef MTP_HOST
62     // write our buffer to the given endpoint (host mode)
write(struct usb_request * request)63 int MtpRequestPacket::write(struct usb_request *request)
64 {
65     putUInt32(MTP_CONTAINER_LENGTH_OFFSET, mPacketSize);
66     putUInt16(MTP_CONTAINER_TYPE_OFFSET, MTP_CONTAINER_TYPE_COMMAND);
67     request->buffer = mBuffer;
68     request->buffer_length = mPacketSize;
69     return transfer(request);
70 }
71 #endif
72 
73 }  // namespace android
74