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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 "MtpDevice"
     18 
     19 #include "MtpDebug.h"
     20 #include "MtpDevice.h"
     21 #include "MtpDeviceInfo.h"
     22 #include "MtpEventPacket.h"
     23 #include "MtpObjectInfo.h"
     24 #include "MtpProperty.h"
     25 #include "MtpStorageInfo.h"
     26 #include "MtpStringBuffer.h"
     27 #include "MtpUtils.h"
     28 
     29 #include <stdio.h>
     30 #include <stdlib.h>
     31 #include <sys/types.h>
     32 #include <sys/ioctl.h>
     33 #include <sys/stat.h>
     34 #include <fcntl.h>
     35 #include <errno.h>
     36 #include <endian.h>
     37 
     38 #include <usbhost/usbhost.h>
     39 
     40 namespace android {
     41 
     42 namespace {
     43 
     44 static constexpr int USB_CONTROL_TRANSFER_TIMEOUT_MS = 200;
     45 
     46 }  // namespace
     47 
     48 #if 0
     49 static bool isMtpDevice(uint16_t vendor, uint16_t product) {
     50     // Sandisk Sansa Fuze
     51     if (vendor == 0x0781 && product == 0x74c2)
     52         return true;
     53     // Samsung YP-Z5
     54     if (vendor == 0x04e8 && product == 0x503c)
     55         return true;
     56     return false;
     57 }
     58 #endif
     59 
     60 namespace {
     61 
     62 bool writeToFd(void* data, uint32_t /* unused_offset */, uint32_t length, void* clientData) {
     63     const int fd = *static_cast<int*>(clientData);
     64     const ssize_t result = write(fd, data, length);
     65     if (result < 0) {
     66         return false;
     67     }
     68     return static_cast<uint32_t>(result) == length;
     69 }
     70 
     71 }  // namespace
     72 
     73 MtpDevice* MtpDevice::open(const char* deviceName, int fd) {
     74     struct usb_device *device = usb_device_new(deviceName, fd);
     75     if (!device) {
     76         ALOGE("usb_device_new failed for %s", deviceName);
     77         return NULL;
     78     }
     79 
     80     struct usb_descriptor_header* desc;
     81     struct usb_descriptor_iter iter;
     82 
     83     usb_descriptor_iter_init(device, &iter);
     84 
     85     while ((desc = usb_descriptor_iter_next(&iter)) != NULL) {
     86         if (desc->bDescriptorType == USB_DT_INTERFACE) {
     87             struct usb_interface_descriptor *interface = (struct usb_interface_descriptor *)desc;
     88 
     89             if (interface->bInterfaceClass == USB_CLASS_STILL_IMAGE &&
     90                 interface->bInterfaceSubClass == 1 && // Still Image Capture
     91                 interface->bInterfaceProtocol == 1)     // Picture Transfer Protocol (PIMA 15470)
     92             {
     93                 char* manufacturerName = usb_device_get_manufacturer_name(device,
     94                         USB_CONTROL_TRANSFER_TIMEOUT_MS);
     95                 char* productName = usb_device_get_product_name(device,
     96                         USB_CONTROL_TRANSFER_TIMEOUT_MS);
     97                 ALOGD("Found camera: \"%s\" \"%s\"\n", manufacturerName, productName);
     98                 free(manufacturerName);
     99                 free(productName);
    100             } else if (interface->bInterfaceClass == 0xFF &&
    101                     interface->bInterfaceSubClass == 0xFF &&
    102                     interface->bInterfaceProtocol == 0) {
    103                 char* interfaceName = usb_device_get_string(device, interface->iInterface,
    104                         USB_CONTROL_TRANSFER_TIMEOUT_MS);
    105                 if (!interfaceName) {
    106                     continue;
    107                 } else if (strcmp(interfaceName, "MTP")) {
    108                     free(interfaceName);
    109                     continue;
    110                 }
    111                 free(interfaceName);
    112 
    113                 // Looks like an android style MTP device
    114                 char* manufacturerName = usb_device_get_manufacturer_name(device,
    115                         USB_CONTROL_TRANSFER_TIMEOUT_MS);
    116                 char* productName = usb_device_get_product_name(device,
    117                         USB_CONTROL_TRANSFER_TIMEOUT_MS);
    118                 ALOGD("Found MTP device: \"%s\" \"%s\"\n", manufacturerName, productName);
    119                 free(manufacturerName);
    120                 free(productName);
    121             }
    122 #if 0
    123              else {
    124                 // look for special cased devices based on vendor/product ID
    125                 // we are doing this mainly for testing purposes
    126                 uint16_t vendor = usb_device_get_vendor_id(device);
    127                 uint16_t product = usb_device_get_product_id(device);
    128                 if (!isMtpDevice(vendor, product)) {
    129                     // not an MTP or PTP device
    130                     continue;
    131                 }
    132                 // request MTP OS string and descriptor
    133                 // some music players need to see this before entering MTP mode.
    134                 char buffer[256];
    135                 memset(buffer, 0, sizeof(buffer));
    136                 int ret = usb_device_control_transfer(device,
    137                         USB_DIR_IN|USB_RECIP_DEVICE|USB_TYPE_STANDARD,
    138                         USB_REQ_GET_DESCRIPTOR, (USB_DT_STRING << 8) | 0xEE,
    139                         0, buffer, sizeof(buffer), 0);
    140                 printf("usb_device_control_transfer returned %d errno: %d\n", ret, errno);
    141                 if (ret > 0) {
    142                     printf("got MTP string %s\n", buffer);
    143                     ret = usb_device_control_transfer(device,
    144                             USB_DIR_IN|USB_RECIP_DEVICE|USB_TYPE_VENDOR, 1,
    145                             0, 4, buffer, sizeof(buffer), 0);
    146                     printf("OS descriptor got %d\n", ret);
    147                 } else {
    148                     printf("no MTP string\n");
    149                 }
    150             }
    151 #else
    152             else {
    153                 continue;
    154             }
    155 #endif
    156             // if we got here, then we have a likely MTP or PTP device
    157 
    158             // interface should be followed by three endpoints
    159             struct usb_endpoint_descriptor *ep;
    160             struct usb_endpoint_descriptor *ep_in_desc = NULL;
    161             struct usb_endpoint_descriptor *ep_out_desc = NULL;
    162             struct usb_endpoint_descriptor *ep_intr_desc = NULL;
    163             //USB3 add USB_DT_SS_ENDPOINT_COMP as companion descriptor;
    164             struct usb_ss_ep_comp_descriptor *ep_ss_ep_comp_desc = NULL;
    165             for (int i = 0; i < 3; i++) {
    166                 ep = (struct usb_endpoint_descriptor *)usb_descriptor_iter_next(&iter);
    167                 if (ep && ep->bDescriptorType == USB_DT_SS_ENDPOINT_COMP) {
    168                     ALOGD("Descriptor type is USB_DT_SS_ENDPOINT_COMP for USB3 \n");
    169                     ep_ss_ep_comp_desc = (usb_ss_ep_comp_descriptor*)ep;
    170                     ep = (struct usb_endpoint_descriptor *)usb_descriptor_iter_next(&iter);
    171                  }
    172 
    173                 if (!ep || ep->bDescriptorType != USB_DT_ENDPOINT) {
    174                     ALOGE("endpoints not found\n");
    175                     usb_device_close(device);
    176                     return NULL;
    177                 }
    178 
    179                 if (ep->bmAttributes == USB_ENDPOINT_XFER_BULK) {
    180                     if (ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
    181                         ep_in_desc = ep;
    182                     else
    183                         ep_out_desc = ep;
    184                 } else if (ep->bmAttributes == USB_ENDPOINT_XFER_INT &&
    185                     ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) {
    186                     ep_intr_desc = ep;
    187                 }
    188             }
    189             if (!ep_in_desc || !ep_out_desc || !ep_intr_desc) {
    190                 ALOGE("endpoints not found\n");
    191                 usb_device_close(device);
    192                 return NULL;
    193             }
    194 
    195             int ret = usb_device_claim_interface(device, interface->bInterfaceNumber);
    196             if (ret && errno == EBUSY) {
    197                 // disconnect kernel driver and try again
    198                 usb_device_connect_kernel_driver(device, interface->bInterfaceNumber, false);
    199                 ret = usb_device_claim_interface(device, interface->bInterfaceNumber);
    200             }
    201             if (ret) {
    202                 ALOGE("usb_device_claim_interface failed errno: %d\n", errno);
    203                 usb_device_close(device);
    204                 return NULL;
    205             }
    206 
    207             MtpDevice* mtpDevice = new MtpDevice(device, interface->bInterfaceNumber,
    208                         ep_in_desc, ep_out_desc, ep_intr_desc);
    209             mtpDevice->initialize();
    210             return mtpDevice;
    211         }
    212     }
    213 
    214     usb_device_close(device);
    215     ALOGE("device not found");
    216     return NULL;
    217 }
    218 
    219 MtpDevice::MtpDevice(struct usb_device* device, int interface,
    220             const struct usb_endpoint_descriptor *ep_in,
    221             const struct usb_endpoint_descriptor *ep_out,
    222             const struct usb_endpoint_descriptor *ep_intr)
    223     :   mDevice(device),
    224         mInterface(interface),
    225         mRequestIn1(NULL),
    226         mRequestIn2(NULL),
    227         mRequestOut(NULL),
    228         mRequestIntr(NULL),
    229         mDeviceInfo(NULL),
    230         mSessionID(0),
    231         mTransactionID(0),
    232         mReceivedResponse(false),
    233         mProcessingEvent(false),
    234         mCurrentEventHandle(0),
    235         mLastSendObjectInfoTransactionID(0),
    236         mLastSendObjectInfoObjectHandle(0),
    237         mPacketDivisionMode(FIRST_PACKET_HAS_PAYLOAD)
    238 {
    239     mRequestIn1 = usb_request_new(device, ep_in);
    240     mRequestIn2 = usb_request_new(device, ep_in);
    241     mRequestOut = usb_request_new(device, ep_out);
    242     mRequestIntr = usb_request_new(device, ep_intr);
    243 }
    244 
    245 MtpDevice::~MtpDevice() {
    246     close();
    247     for (size_t i = 0; i < mDeviceProperties.size(); i++)
    248         delete mDeviceProperties[i];
    249     usb_request_free(mRequestIn1);
    250     usb_request_free(mRequestIn2);
    251     usb_request_free(mRequestOut);
    252     usb_request_free(mRequestIntr);
    253 }
    254 
    255 void MtpDevice::initialize() {
    256     openSession();
    257     mDeviceInfo = getDeviceInfo();
    258     if (mDeviceInfo) {
    259         if (mDeviceInfo->mDeviceProperties) {
    260             int count = mDeviceInfo->mDeviceProperties->size();
    261             for (int i = 0; i < count; i++) {
    262                 MtpDeviceProperty propCode = (*mDeviceInfo->mDeviceProperties)[i];
    263                 MtpProperty* property = getDevicePropDesc(propCode);
    264                 if (property)
    265                     mDeviceProperties.push_back(property);
    266             }
    267         }
    268     }
    269 }
    270 
    271 void MtpDevice::close() {
    272     if (mDevice) {
    273         usb_device_release_interface(mDevice, mInterface);
    274         usb_device_close(mDevice);
    275         mDevice = NULL;
    276     }
    277 }
    278 
    279 void MtpDevice::print() {
    280     if (!mDeviceInfo)
    281         return;
    282 
    283     mDeviceInfo->print();
    284 
    285     if (mDeviceInfo->mDeviceProperties) {
    286         ALOGI("***** DEVICE PROPERTIES *****\n");
    287         int count = mDeviceInfo->mDeviceProperties->size();
    288         for (int i = 0; i < count; i++) {
    289             MtpDeviceProperty propCode = (*mDeviceInfo->mDeviceProperties)[i];
    290             MtpProperty* property = getDevicePropDesc(propCode);
    291             if (property) {
    292                 property->print();
    293                 delete property;
    294             }
    295         }
    296     }
    297 
    298     if (mDeviceInfo->mPlaybackFormats) {
    299             ALOGI("***** OBJECT PROPERTIES *****\n");
    300         int count = mDeviceInfo->mPlaybackFormats->size();
    301         for (int i = 0; i < count; i++) {
    302             MtpObjectFormat format = (*mDeviceInfo->mPlaybackFormats)[i];
    303             ALOGI("*** FORMAT: %s\n", MtpDebug::getFormatCodeName(format));
    304             MtpObjectPropertyList* props = getObjectPropsSupported(format);
    305             if (props) {
    306                 for (size_t j = 0; j < props->size(); j++) {
    307                     MtpObjectProperty prop = (*props)[j];
    308                     MtpProperty* property = getObjectPropDesc(prop, format);
    309                     if (property) {
    310                         property->print();
    311                         delete property;
    312                     } else {
    313                         ALOGE("could not fetch property: %s",
    314                                 MtpDebug::getObjectPropCodeName(prop));
    315                     }
    316                 }
    317             }
    318         }
    319     }
    320 }
    321 
    322 const char* MtpDevice::getDeviceName() {
    323     if (mDevice)
    324         return usb_device_get_name(mDevice);
    325     else
    326         return "???";
    327 }
    328 
    329 bool MtpDevice::openSession() {
    330     std::lock_guard<std::mutex> lg(mMutex);
    331 
    332     mSessionID = 0;
    333     mTransactionID = 0;
    334     MtpSessionID newSession = 1;
    335     mRequest.reset();
    336     mRequest.setParameter(1, newSession);
    337     if (!sendRequest(MTP_OPERATION_OPEN_SESSION))
    338         return false;
    339     MtpResponseCode ret = readResponse();
    340     if (ret == MTP_RESPONSE_SESSION_ALREADY_OPEN)
    341         newSession = mResponse.getParameter(1);
    342     else if (ret != MTP_RESPONSE_OK)
    343         return false;
    344 
    345     mSessionID = newSession;
    346     mTransactionID = 1;
    347     return true;
    348 }
    349 
    350 bool MtpDevice::closeSession() {
    351     // FIXME
    352     return true;
    353 }
    354 
    355 MtpDeviceInfo* MtpDevice::getDeviceInfo() {
    356     std::lock_guard<std::mutex> lg(mMutex);
    357 
    358     mRequest.reset();
    359     if (!sendRequest(MTP_OPERATION_GET_DEVICE_INFO))
    360         return NULL;
    361     if (!readData())
    362         return NULL;
    363     MtpResponseCode ret = readResponse();
    364     if (ret == MTP_RESPONSE_OK) {
    365         MtpDeviceInfo* info = new MtpDeviceInfo;
    366         if (info->read(mData))
    367             return info;
    368         else
    369             delete info;
    370     }
    371     return NULL;
    372 }
    373 
    374 MtpStorageIDList* MtpDevice::getStorageIDs() {
    375     std::lock_guard<std::mutex> lg(mMutex);
    376 
    377     mRequest.reset();
    378     if (!sendRequest(MTP_OPERATION_GET_STORAGE_IDS))
    379         return NULL;
    380     if (!readData())
    381         return NULL;
    382     MtpResponseCode ret = readResponse();
    383     if (ret == MTP_RESPONSE_OK) {
    384         return mData.getAUInt32();
    385     }
    386     return NULL;
    387 }
    388 
    389 MtpStorageInfo* MtpDevice::getStorageInfo(MtpStorageID storageID) {
    390     std::lock_guard<std::mutex> lg(mMutex);
    391 
    392     mRequest.reset();
    393     mRequest.setParameter(1, storageID);
    394     if (!sendRequest(MTP_OPERATION_GET_STORAGE_INFO))
    395         return NULL;
    396     if (!readData())
    397         return NULL;
    398     MtpResponseCode ret = readResponse();
    399     if (ret == MTP_RESPONSE_OK) {
    400         MtpStorageInfo* info = new MtpStorageInfo(storageID);
    401         if (info->read(mData))
    402             return info;
    403         else
    404             delete info;
    405     }
    406     return NULL;
    407 }
    408 
    409 MtpObjectHandleList* MtpDevice::getObjectHandles(MtpStorageID storageID,
    410             MtpObjectFormat format, MtpObjectHandle parent) {
    411     std::lock_guard<std::mutex> lg(mMutex);
    412 
    413     mRequest.reset();
    414     mRequest.setParameter(1, storageID);
    415     mRequest.setParameter(2, format);
    416     mRequest.setParameter(3, parent);
    417     if (!sendRequest(MTP_OPERATION_GET_OBJECT_HANDLES))
    418         return NULL;
    419     if (!readData())
    420         return NULL;
    421     MtpResponseCode ret = readResponse();
    422     if (ret == MTP_RESPONSE_OK) {
    423         return mData.getAUInt32();
    424     }
    425     return NULL;
    426 }
    427 
    428 MtpObjectInfo* MtpDevice::getObjectInfo(MtpObjectHandle handle) {
    429     std::lock_guard<std::mutex> lg(mMutex);
    430 
    431     // FIXME - we might want to add some caching here
    432 
    433     mRequest.reset();
    434     mRequest.setParameter(1, handle);
    435     if (!sendRequest(MTP_OPERATION_GET_OBJECT_INFO))
    436         return NULL;
    437     if (!readData())
    438         return NULL;
    439     MtpResponseCode ret = readResponse();
    440     if (ret == MTP_RESPONSE_OK) {
    441         MtpObjectInfo* info = new MtpObjectInfo(handle);
    442         if (info->read(mData))
    443             return info;
    444         else
    445             delete info;
    446     }
    447     return NULL;
    448 }
    449 
    450 void* MtpDevice::getThumbnail(MtpObjectHandle handle, int& outLength) {
    451     std::lock_guard<std::mutex> lg(mMutex);
    452 
    453     mRequest.reset();
    454     mRequest.setParameter(1, handle);
    455     if (sendRequest(MTP_OPERATION_GET_THUMB) && readData()) {
    456         MtpResponseCode ret = readResponse();
    457         if (ret == MTP_RESPONSE_OK) {
    458             return mData.getData(&outLength);
    459         }
    460     }
    461     outLength = 0;
    462     return NULL;
    463 }
    464 
    465 MtpObjectHandle MtpDevice::sendObjectInfo(MtpObjectInfo* info) {
    466     std::lock_guard<std::mutex> lg(mMutex);
    467 
    468     mRequest.reset();
    469     MtpObjectHandle parent = info->mParent;
    470     if (parent == 0)
    471         parent = MTP_PARENT_ROOT;
    472 
    473     mRequest.setParameter(1, info->mStorageID);
    474     mRequest.setParameter(2, parent);
    475 
    476     mData.reset();
    477     mData.putUInt32(info->mStorageID);
    478     mData.putUInt16(info->mFormat);
    479     mData.putUInt16(info->mProtectionStatus);
    480     mData.putUInt32(info->mCompressedSize);
    481     mData.putUInt16(info->mThumbFormat);
    482     mData.putUInt32(info->mThumbCompressedSize);
    483     mData.putUInt32(info->mThumbPixWidth);
    484     mData.putUInt32(info->mThumbPixHeight);
    485     mData.putUInt32(info->mImagePixWidth);
    486     mData.putUInt32(info->mImagePixHeight);
    487     mData.putUInt32(info->mImagePixDepth);
    488     mData.putUInt32(info->mParent);
    489     mData.putUInt16(info->mAssociationType);
    490     mData.putUInt32(info->mAssociationDesc);
    491     mData.putUInt32(info->mSequenceNumber);
    492     mData.putString(info->mName);
    493 
    494     char created[100], modified[100];
    495     formatDateTime(info->mDateCreated, created, sizeof(created));
    496     formatDateTime(info->mDateModified, modified, sizeof(modified));
    497 
    498     mData.putString(created);
    499     mData.putString(modified);
    500     if (info->mKeywords)
    501         mData.putString(info->mKeywords);
    502     else
    503         mData.putEmptyString();
    504 
    505    if (sendRequest(MTP_OPERATION_SEND_OBJECT_INFO) && sendData()) {
    506         MtpResponseCode ret = readResponse();
    507         if (ret == MTP_RESPONSE_OK) {
    508             mLastSendObjectInfoTransactionID = mRequest.getTransactionID();
    509             mLastSendObjectInfoObjectHandle = mResponse.getParameter(3);
    510             info->mStorageID = mResponse.getParameter(1);
    511             info->mParent = mResponse.getParameter(2);
    512             info->mHandle = mResponse.getParameter(3);
    513             return info->mHandle;
    514         }
    515     }
    516     return (MtpObjectHandle)-1;
    517 }
    518 
    519 bool MtpDevice::sendObject(MtpObjectHandle handle, int size, int srcFD) {
    520     std::lock_guard<std::mutex> lg(mMutex);
    521 
    522     if (mLastSendObjectInfoTransactionID + 1 != mTransactionID ||
    523             mLastSendObjectInfoObjectHandle != handle) {
    524         ALOGE("A sendObject request must follow the sendObjectInfo request.");
    525         return false;
    526     }
    527 
    528     mRequest.reset();
    529     if (sendRequest(MTP_OPERATION_SEND_OBJECT)) {
    530         mData.setOperationCode(mRequest.getOperationCode());
    531         mData.setTransactionID(mRequest.getTransactionID());
    532         const int writeResult = mData.write(mRequestOut, mPacketDivisionMode, srcFD, size);
    533         const MtpResponseCode ret = readResponse();
    534         return ret == MTP_RESPONSE_OK && writeResult > 0;
    535     }
    536     return false;
    537 }
    538 
    539 bool MtpDevice::deleteObject(MtpObjectHandle handle) {
    540     std::lock_guard<std::mutex> lg(mMutex);
    541 
    542     mRequest.reset();
    543     mRequest.setParameter(1, handle);
    544     if (sendRequest(MTP_OPERATION_DELETE_OBJECT)) {
    545         MtpResponseCode ret = readResponse();
    546         if (ret == MTP_RESPONSE_OK)
    547             return true;
    548     }
    549     return false;
    550 }
    551 
    552 MtpObjectHandle MtpDevice::getParent(MtpObjectHandle handle) {
    553     MtpObjectInfo* info = getObjectInfo(handle);
    554     if (info) {
    555         MtpObjectHandle parent = info->mParent;
    556         delete info;
    557         return parent;
    558     } else {
    559         return -1;
    560     }
    561 }
    562 
    563 MtpObjectHandle MtpDevice::getStorageID(MtpObjectHandle handle) {
    564     MtpObjectInfo* info = getObjectInfo(handle);
    565     if (info) {
    566         MtpObjectHandle storageId = info->mStorageID;
    567         delete info;
    568         return storageId;
    569     } else {
    570         return -1;
    571     }
    572 }
    573 
    574 MtpObjectPropertyList* MtpDevice::getObjectPropsSupported(MtpObjectFormat format) {
    575     std::lock_guard<std::mutex> lg(mMutex);
    576 
    577     mRequest.reset();
    578     mRequest.setParameter(1, format);
    579     if (!sendRequest(MTP_OPERATION_GET_OBJECT_PROPS_SUPPORTED))
    580         return NULL;
    581     if (!readData())
    582         return NULL;
    583     MtpResponseCode ret = readResponse();
    584     if (ret == MTP_RESPONSE_OK) {
    585         return mData.getAUInt16();
    586     }
    587     return NULL;
    588 
    589 }
    590 
    591 MtpProperty* MtpDevice::getDevicePropDesc(MtpDeviceProperty code) {
    592     std::lock_guard<std::mutex> lg(mMutex);
    593 
    594     mRequest.reset();
    595     mRequest.setParameter(1, code);
    596     if (!sendRequest(MTP_OPERATION_GET_DEVICE_PROP_DESC))
    597         return NULL;
    598     if (!readData())
    599         return NULL;
    600     MtpResponseCode ret = readResponse();
    601     if (ret == MTP_RESPONSE_OK) {
    602         MtpProperty* property = new MtpProperty;
    603         if (property->read(mData))
    604             return property;
    605         else
    606             delete property;
    607     }
    608     return NULL;
    609 }
    610 
    611 MtpProperty* MtpDevice::getObjectPropDesc(MtpObjectProperty code, MtpObjectFormat format) {
    612     std::lock_guard<std::mutex> lg(mMutex);
    613 
    614     mRequest.reset();
    615     mRequest.setParameter(1, code);
    616     mRequest.setParameter(2, format);
    617     if (!sendRequest(MTP_OPERATION_GET_OBJECT_PROP_DESC))
    618         return NULL;
    619     if (!readData())
    620         return NULL;
    621     const MtpResponseCode ret = readResponse();
    622     if (ret == MTP_RESPONSE_OK) {
    623         MtpProperty* property = new MtpProperty;
    624         if (property->read(mData))
    625             return property;
    626         else
    627             delete property;
    628     }
    629     return NULL;
    630 }
    631 
    632 bool MtpDevice::getObjectPropValue(MtpObjectHandle handle, MtpProperty* property) {
    633     if (property == nullptr)
    634         return false;
    635 
    636     std::lock_guard<std::mutex> lg(mMutex);
    637 
    638     mRequest.reset();
    639     mRequest.setParameter(1, handle);
    640     mRequest.setParameter(2, property->getPropertyCode());
    641     if (!sendRequest(MTP_OPERATION_GET_OBJECT_PROP_VALUE))
    642         return false;
    643     if (!readData())
    644         return false;
    645     if (readResponse() != MTP_RESPONSE_OK)
    646         return false;
    647     property->setCurrentValue(mData);
    648     return true;
    649 }
    650 
    651 bool MtpDevice::readObject(MtpObjectHandle handle,
    652                            ReadObjectCallback callback,
    653                            uint32_t expectedLength,
    654                            void* clientData) {
    655     return readObjectInternal(handle, callback, &expectedLength, clientData);
    656 }
    657 
    658 // reads the object's data and writes it to the specified file path
    659 bool MtpDevice::readObject(MtpObjectHandle handle, const char* destPath, int group, int perm) {
    660     ALOGD("readObject: %s", destPath);
    661     int fd = ::open(destPath, O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
    662     if (fd < 0) {
    663         ALOGE("open failed for %s", destPath);
    664         return false;
    665     }
    666 
    667     fchown(fd, getuid(), group);
    668     // set permissions
    669     int mask = umask(0);
    670     fchmod(fd, perm);
    671     umask(mask);
    672 
    673     bool result = readObject(handle, fd);
    674     ::close(fd);
    675     return result;
    676 }
    677 
    678 bool MtpDevice::readObject(MtpObjectHandle handle, int fd) {
    679     ALOGD("readObject: %d", fd);
    680     return readObjectInternal(handle, writeToFd, NULL /* expected size */, &fd);
    681 }
    682 
    683 bool MtpDevice::readObjectInternal(MtpObjectHandle handle,
    684                                    ReadObjectCallback callback,
    685                                    const uint32_t* expectedLength,
    686                                    void* clientData) {
    687     std::lock_guard<std::mutex> lg(mMutex);
    688 
    689     mRequest.reset();
    690     mRequest.setParameter(1, handle);
    691     if (!sendRequest(MTP_OPERATION_GET_OBJECT)) {
    692         ALOGE("Failed to send a read request.");
    693         return false;
    694     }
    695 
    696     return readData(callback, expectedLength, nullptr, clientData);
    697 }
    698 
    699 bool MtpDevice::readData(ReadObjectCallback callback,
    700                             const uint32_t* expectedLength,
    701                             uint32_t* writtenSize,
    702                             void* clientData) {
    703     if (!mData.readDataHeader(mRequestIn1)) {
    704         ALOGE("Failed to read header.");
    705         return false;
    706     }
    707 
    708     // If object size 0 byte, the remote device may reply a response packet without sending any data
    709     // packets.
    710     if (mData.getContainerType() == MTP_CONTAINER_TYPE_RESPONSE) {
    711         mResponse.copyFrom(mData);
    712         return mResponse.getResponseCode() == MTP_RESPONSE_OK;
    713     }
    714 
    715     const uint32_t fullLength = mData.getContainerLength();
    716     if (fullLength < MTP_CONTAINER_HEADER_SIZE) {
    717         ALOGE("fullLength is too short: %d", fullLength);
    718         return false;
    719     }
    720     const uint32_t length = fullLength - MTP_CONTAINER_HEADER_SIZE;
    721     if (expectedLength && length != *expectedLength) {
    722         ALOGE("readObject error length: %d", fullLength);
    723         return false;
    724     }
    725 
    726     uint32_t offset = 0;
    727     bool writingError = false;
    728 
    729     {
    730         int initialDataLength = 0;
    731         void* const initialData = mData.getData(&initialDataLength);
    732         if (fullLength > MTP_CONTAINER_HEADER_SIZE && initialDataLength == 0) {
    733             // According to the MTP spec, the responder (MTP device) can choose two ways of sending
    734             // data. a) The first packet contains the head and as much of the payload as possible
    735             // b) The first packet contains only the header. The initiator (MTP host) needs
    736             // to remember which way the responder used, and send upcoming data in the same way.
    737             ALOGD("Found short packet that contains only a header.");
    738             mPacketDivisionMode = FIRST_PACKET_ONLY_HEADER;
    739         }
    740         if (initialData) {
    741             if (initialDataLength > 0) {
    742                 if (!callback(initialData, offset, initialDataLength, clientData)) {
    743                     ALOGE("Failed to write initial data.");
    744                     writingError = true;
    745                 }
    746                 offset += initialDataLength;
    747             }
    748             free(initialData);
    749         }
    750     }
    751 
    752     // USB reads greater than 16K don't work.
    753     char buffer1[MTP_BUFFER_SIZE], buffer2[MTP_BUFFER_SIZE];
    754     mRequestIn1->buffer = buffer1;
    755     mRequestIn2->buffer = buffer2;
    756     struct usb_request* req = NULL;
    757 
    758     while (offset < length) {
    759         // Wait for previous read to complete.
    760         void* writeBuffer = NULL;
    761         int writeLength = 0;
    762         if (req) {
    763             const int read = mData.readDataWait(mDevice);
    764             if (read < 0) {
    765                 ALOGE("readDataWait failed.");
    766                 return false;
    767             }
    768             writeBuffer = req->buffer;
    769             writeLength = read;
    770         }
    771 
    772         // Request to read next chunk.
    773         const uint32_t nextOffset = offset + writeLength;
    774         if (nextOffset < length) {
    775             // Queue up a read request.
    776             const size_t remaining = length - nextOffset;
    777             req = (req == mRequestIn1 ? mRequestIn2 : mRequestIn1);
    778             req->buffer_length = remaining > MTP_BUFFER_SIZE ?
    779                     static_cast<size_t>(MTP_BUFFER_SIZE) : remaining;
    780             if (mData.readDataAsync(req) != 0) {
    781                 ALOGE("readDataAsync failed");
    782                 return false;
    783             }
    784         }
    785 
    786         // Write previous buffer.
    787         if (writeBuffer && !writingError) {
    788             if (!callback(writeBuffer, offset, writeLength, clientData)) {
    789                 ALOGE("write failed");
    790                 writingError = true;
    791             }
    792         }
    793         offset = nextOffset;
    794     }
    795 
    796     if (writtenSize) {
    797         *writtenSize = length;
    798     }
    799 
    800     return readResponse() == MTP_RESPONSE_OK;
    801 }
    802 
    803 bool MtpDevice::readPartialObject(MtpObjectHandle handle,
    804                                   uint32_t offset,
    805                                   uint32_t size,
    806                                   uint32_t *writtenSize,
    807                                   ReadObjectCallback callback,
    808                                   void* clientData) {
    809     std::lock_guard<std::mutex> lg(mMutex);
    810 
    811     mRequest.reset();
    812     mRequest.setParameter(1, handle);
    813     mRequest.setParameter(2, offset);
    814     mRequest.setParameter(3, size);
    815     if (!sendRequest(MTP_OPERATION_GET_PARTIAL_OBJECT)) {
    816         ALOGE("Failed to send a read request.");
    817         return false;
    818     }
    819     // The expected size is null because it requires the exact number of bytes to read though
    820     // MTP_OPERATION_GET_PARTIAL_OBJECT allows devices to return shorter length of bytes than
    821     // requested. Destination's buffer length should be checked in |callback|.
    822     return readData(callback, nullptr /* expected size */, writtenSize, clientData);
    823 }
    824 
    825 bool MtpDevice::readPartialObject64(MtpObjectHandle handle,
    826                                     uint64_t offset,
    827                                     uint32_t size,
    828                                     uint32_t *writtenSize,
    829                                     ReadObjectCallback callback,
    830                                     void* clientData) {
    831     std::lock_guard<std::mutex> lg(mMutex);
    832 
    833     mRequest.reset();
    834     mRequest.setParameter(1, handle);
    835     mRequest.setParameter(2, 0xffffffff & offset);
    836     mRequest.setParameter(3, 0xffffffff & (offset >> 32));
    837     mRequest.setParameter(4, size);
    838     if (!sendRequest(MTP_OPERATION_GET_PARTIAL_OBJECT_64)) {
    839         ALOGE("Failed to send a read request.");
    840         return false;
    841     }
    842     // The expected size is null because it requires the exact number of bytes to read though
    843     // MTP_OPERATION_GET_PARTIAL_OBJECT_64 allows devices to return shorter length of bytes than
    844     // requested. Destination's buffer length should be checked in |callback|.
    845     return readData(callback, nullptr /* expected size */, writtenSize, clientData);
    846 }
    847 
    848 bool MtpDevice::sendRequest(MtpOperationCode operation) {
    849     ALOGV("sendRequest: %s\n", MtpDebug::getOperationCodeName(operation));
    850     mReceivedResponse = false;
    851     mRequest.setOperationCode(operation);
    852     if (mTransactionID > 0)
    853         mRequest.setTransactionID(mTransactionID++);
    854     int ret = mRequest.write(mRequestOut);
    855     mRequest.dump();
    856     return (ret > 0);
    857 }
    858 
    859 bool MtpDevice::sendData() {
    860     ALOGV("sendData\n");
    861     mData.setOperationCode(mRequest.getOperationCode());
    862     mData.setTransactionID(mRequest.getTransactionID());
    863     int ret = mData.write(mRequestOut, mPacketDivisionMode);
    864     mData.dump();
    865     return (ret >= 0);
    866 }
    867 
    868 bool MtpDevice::readData() {
    869     mData.reset();
    870     int ret = mData.read(mRequestIn1);
    871     ALOGV("readData returned %d\n", ret);
    872     if (ret >= MTP_CONTAINER_HEADER_SIZE) {
    873         if (mData.getContainerType() == MTP_CONTAINER_TYPE_RESPONSE) {
    874             ALOGD("got response packet instead of data packet");
    875             // we got a response packet rather than data
    876             // copy it to mResponse
    877             mResponse.copyFrom(mData);
    878             mReceivedResponse = true;
    879             return false;
    880         }
    881         mData.dump();
    882         return true;
    883     }
    884     else {
    885         ALOGV("readResponse failed\n");
    886         return false;
    887     }
    888 }
    889 
    890 MtpResponseCode MtpDevice::readResponse() {
    891     ALOGV("readResponse\n");
    892     if (mReceivedResponse) {
    893         mReceivedResponse = false;
    894         return mResponse.getResponseCode();
    895     }
    896     int ret = mResponse.read(mRequestIn1);
    897     // handle zero length packets, which might occur if the data transfer
    898     // ends on a packet boundary
    899     if (ret == 0)
    900         ret = mResponse.read(mRequestIn1);
    901     if (ret >= MTP_CONTAINER_HEADER_SIZE) {
    902         mResponse.dump();
    903         return mResponse.getResponseCode();
    904     } else {
    905         ALOGD("readResponse failed\n");
    906         return -1;
    907     }
    908 }
    909 
    910 int MtpDevice::submitEventRequest() {
    911     if (!mEventMutex.try_lock()) {
    912         // An event is being reaped on another thread.
    913         return -1;
    914     }
    915     if (mProcessingEvent) {
    916         // An event request was submitted, but no reapEventRequest called so far.
    917         return -1;
    918     }
    919     std::lock_guard<std::mutex> lg(mEventMutexForInterrupt);
    920     mEventPacket.sendRequest(mRequestIntr);
    921     const int currentHandle = ++mCurrentEventHandle;
    922     mProcessingEvent = true;
    923     mEventMutex.unlock();
    924     return currentHandle;
    925 }
    926 
    927 int MtpDevice::reapEventRequest(int handle, uint32_t (*parameters)[3]) {
    928     std::lock_guard<std::mutex> lg(mEventMutex);
    929     if (!mProcessingEvent || mCurrentEventHandle != handle || !parameters) {
    930         return -1;
    931     }
    932     mProcessingEvent = false;
    933     const int readSize = mEventPacket.readResponse(mRequestIntr->dev);
    934     const int result = mEventPacket.getEventCode();
    935     // MTP event has three parameters.
    936     (*parameters)[0] = mEventPacket.getParameter(1);
    937     (*parameters)[1] = mEventPacket.getParameter(2);
    938     (*parameters)[2] = mEventPacket.getParameter(3);
    939     return readSize != 0 ? result : 0;
    940 }
    941 
    942 void MtpDevice::discardEventRequest(int handle) {
    943     std::lock_guard<std::mutex> lg(mEventMutexForInterrupt);
    944     if (mCurrentEventHandle != handle) {
    945         return;
    946     }
    947     usb_request_cancel(mRequestIntr);
    948 }
    949 
    950 }  // namespace android
    951