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      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 "IMtpHandle.h"
     24 #include "MtpRequestPacket.h"
     25 
     26 #include <usbhost/usbhost.h>
     27 
     28 namespace android {
     29 
     30 MtpRequestPacket::MtpRequestPacket()
     31     :   MtpPacket(512),
     32         mParameterCount(0)
     33 {
     34 }
     35 
     36 MtpRequestPacket::~MtpRequestPacket() {
     37 }
     38 
     39 #ifdef MTP_DEVICE
     40 int MtpRequestPacket::read(IMtpHandle *h) {
     41     int ret = h->read(mBuffer, mBufferSize);
     42     if (ret < 0) {
     43         // file read error
     44         return ret;
     45     }
     46 
     47     // request packet should have 12 byte header followed by 0 to 5 32-bit arguments
     48     const size_t read_size = static_cast<size_t>(ret);
     49     if (read_size >= MTP_CONTAINER_HEADER_SIZE
     50             && read_size <= MTP_CONTAINER_HEADER_SIZE + 5 * sizeof(uint32_t)
     51             && ((read_size - MTP_CONTAINER_HEADER_SIZE) & 3) == 0) {
     52         mPacketSize = read_size;
     53         mParameterCount = (read_size - MTP_CONTAINER_HEADER_SIZE) / sizeof(uint32_t);
     54     } else {
     55         ALOGE("Malformed MTP request packet");
     56         ret = -1;
     57     }
     58     return ret;
     59 }
     60 #endif
     61 
     62 #ifdef MTP_HOST
     63     // write our buffer to the given endpoint (host mode)
     64 int MtpRequestPacket::write(struct usb_request *request)
     65 {
     66     putUInt32(MTP_CONTAINER_LENGTH_OFFSET, mPacketSize);
     67     putUInt16(MTP_CONTAINER_TYPE_OFFSET, MTP_CONTAINER_TYPE_COMMAND);
     68     request->buffer = mBuffer;
     69     request->buffer_length = mPacketSize;
     70     return transfer(request);
     71 }
     72 #endif
     73 
     74 }  // namespace android
     75