Drm.cpp - Android社区 - https://www.androidos.net.cn/

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//#define LOG_NDEBUG 0
#define LOG_TAG "Drm"
#include <utils/Log.h>

#include <dirent.h>
#include <dlfcn.h>

#include <media/DrmSessionClientInterface.h>
#include <media/DrmSessionManager.h>
#include <media/Drm.h>
#include <media/drm/DrmAPI.h>
#include <media/stagefright/foundation/ADebug.h>
#include <media/stagefright/foundation/AString.h>
#include <media/stagefright/foundation/hexdump.h>
#include <media/stagefright/MediaErrors.h>
#include <binder/IServiceManager.h>
#include <binder/IPCThreadState.h>

namespace android {

static inline int getCallingPid() {
    return IPCThreadState::self()->getCallingPid();
}

static bool checkPermission(const char* permissionString) {
    if (getpid() == IPCThreadState::self()->getCallingPid()) return true;
    bool ok = checkCallingPermission(String16(permissionString));
    if (!ok) ALOGE("Request requires %s", permissionString);
    return ok;
}

KeyedVector<Vector<uint8_t>, String8> Drm::mUUIDToLibraryPathMap;
KeyedVector<String8, wp<SharedLibrary> > Drm::mLibraryPathToOpenLibraryMap;
Mutex Drm::mMapLock;
Mutex Drm::mLock;

static bool operator<(const Vector<uint8_t> &lhs, const Vector<uint8_t> &rhs) {
    if (lhs.size() < rhs.size()) {
        return true;
    } else if (lhs.size() > rhs.size()) {
        return false;
    }

return memcmp((void *)lhs.array(), (void *)rhs.array(), rhs.size()) < 0;
}

struct DrmSessionClient : public DrmSessionClientInterface {
    DrmSessionClient(Drm* drm) : mDrm(drm) {}

virtual bool reclaimSession(const Vector<uint8_t>& sessionId) {
        sp<Drm> drm = mDrm.promote();
        if (drm == NULL) {
            return true;
        }
        status_t err = drm->closeSession(sessionId);
        if (err != OK) {
            return false;
        }
        drm->sendEvent(DrmPlugin::kDrmPluginEventSessionReclaimed, 0, &sessionId, NULL);
        return true;
    }

protected:
    virtual ~DrmSessionClient() {}

private:
    wp<Drm> mDrm;

DISALLOW_EVIL_CONSTRUCTORS(DrmSessionClient);
};

Drm::Drm()
    : mInitCheck(NO_INIT),
      mDrmSessionClient(new DrmSessionClient(this)),
      mListener(NULL),
      mFactory(NULL),
      mPlugin(NULL) {
}

Drm::~Drm() {
    DrmSessionManager::Instance()->removeDrm(mDrmSessionClient);
    delete mPlugin;
    mPlugin = NULL;
    closeFactory();
}

void Drm::closeFactory() {
    delete mFactory;
    mFactory = NULL;
    mLibrary.clear();
}

status_t Drm::initCheck() const {
    return mInitCheck;
}

status_t Drm::setListener(const sp<IDrmClient>& listener)
{
    Mutex::Autolock lock(mEventLock);
    if (mListener != NULL){
        IInterface::asBinder(mListener)->unlinkToDeath(this);
    }
    if (listener != NULL) {
        IInterface::asBinder(listener)->linkToDeath(this);
    }
    mListener = listener;
    return NO_ERROR;
}

void Drm::sendEvent(DrmPlugin::EventType eventType, int extra,
                    Vector<uint8_t> const *sessionId,
                    Vector<uint8_t> const *data)
{
    mEventLock.lock();
    sp<IDrmClient> listener = mListener;
    mEventLock.unlock();

if (listener != NULL) {
        Parcel obj;
        writeByteArray(obj, sessionId);
        writeByteArray(obj, data);

Mutex::Autolock lock(mNotifyLock);
        listener->notify(eventType, extra, &obj);
    }
}

void Drm::sendExpirationUpdate(Vector<uint8_t> const *sessionId,
                               int64_t expiryTimeInMS)
{
    mEventLock.lock();
    sp<IDrmClient> listener = mListener;
    mEventLock.unlock();

if (listener != NULL) {
        Parcel obj;
        writeByteArray(obj, sessionId);
        obj.writeInt64(expiryTimeInMS);

Mutex::Autolock lock(mNotifyLock);
        listener->notify(DrmPlugin::kDrmPluginEventExpirationUpdate, 0, &obj);
    }
}

void Drm::sendKeysChange(Vector<uint8_t> const *sessionId,
                         Vector<DrmPlugin::KeyStatus> const *keyStatusList,
                         bool hasNewUsableKey)
{
    mEventLock.lock();
    sp<IDrmClient> listener = mListener;
    mEventLock.unlock();

if (listener != NULL) {
        Parcel obj;
        writeByteArray(obj, sessionId);

size_t nkeys = keyStatusList->size();
        obj.writeInt32(keyStatusList->size());
        for (size_t i = 0; i < nkeys; ++i) {
            const DrmPlugin::KeyStatus *keyStatus = &keyStatusList->itemAt(i);
            writeByteArray(obj, &keyStatus->mKeyId);
            obj.writeInt32(keyStatus->mType);
        }
        obj.writeInt32(hasNewUsableKey);

Mutex::Autolock lock(mNotifyLock);
        listener->notify(DrmPlugin::kDrmPluginEventKeysChange, 0, &obj);
    }
}

/*
 * Search the plugins directory for a plugin that supports the scheme
 * specified by uuid
 *
 * If found:
 *    mLibrary holds a strong pointer to the dlopen'd library
 *    mFactory is set to the library's factory method
 *    mInitCheck is set to OK
 *
 * If not found:
 *    mLibrary is cleared and mFactory are set to NULL
 *    mInitCheck is set to an error (!OK)
 */
void Drm::findFactoryForScheme(const uint8_t uuid[16]) {

closeFactory();

// lock static maps
    Mutex::Autolock autoLock(mMapLock);

// first check cache
    Vector<uint8_t> uuidVector;
    uuidVector.appendArray(uuid, sizeof(uuid[0]) * 16);
    ssize_t index = mUUIDToLibraryPathMap.indexOfKey(uuidVector);
    if (index >= 0) {
        if (loadLibraryForScheme(mUUIDToLibraryPathMap[index], uuid)) {
            mInitCheck = OK;
            return;
        } else {
            ALOGE("Failed to load from cached library path!");
            mInitCheck = ERROR_UNSUPPORTED;
            return;
        }
    }

// no luck, have to search
    String8 dirPath("/vendor/lib/mediadrm");
    DIR* pDir = opendir(dirPath.string());

if (pDir == NULL) {
        mInitCheck = ERROR_UNSUPPORTED;
        ALOGE("Failed to open plugin directory %s", dirPath.string());
        return;
    }

struct dirent* pEntry;
    while ((pEntry = readdir(pDir))) {

String8 pluginPath = dirPath + "/" + pEntry->d_name;

if (pluginPath.getPathExtension() == ".so") {

if (loadLibraryForScheme(pluginPath, uuid)) {
                mUUIDToLibraryPathMap.add(uuidVector, pluginPath);
                mInitCheck = OK;
                closedir(pDir);
                return;
            }
        }
    }

closedir(pDir);

ALOGE("Failed to find drm plugin");
    mInitCheck = ERROR_UNSUPPORTED;
}

bool Drm::loadLibraryForScheme(const String8 &path, const uint8_t uuid[16]) {

// get strong pointer to open shared library
    ssize_t index = mLibraryPathToOpenLibraryMap.indexOfKey(path);
    if (index >= 0) {
        mLibrary = mLibraryPathToOpenLibraryMap[index].promote();
    } else {
        index = mLibraryPathToOpenLibraryMap.add(path, NULL);
    }

if (!mLibrary.get()) {
        mLibrary = new SharedLibrary(path);
        if (!*mLibrary) {
            return false;
        }

mLibraryPathToOpenLibraryMap.replaceValueAt(index, mLibrary);
    }

typedef DrmFactory *(*CreateDrmFactoryFunc)();

CreateDrmFactoryFunc createDrmFactory =
        (CreateDrmFactoryFunc)mLibrary->lookup("createDrmFactory");

if (createDrmFactory == NULL ||
        (mFactory = createDrmFactory()) == NULL ||
        !mFactory->isCryptoSchemeSupported(uuid)) {
        closeFactory();
        return false;
    }
    return true;
}

bool Drm::isCryptoSchemeSupported(const uint8_t uuid[16], const String8 &mimeType) {

Mutex::Autolock autoLock(mLock);

if (!mFactory || !mFactory->isCryptoSchemeSupported(uuid)) {
        findFactoryForScheme(uuid);
        if (mInitCheck != OK) {
            return false;
        }
    }

if (mimeType != "") {
        return mFactory->isContentTypeSupported(mimeType);
    }

return true;
}

status_t Drm::createPlugin(const uint8_t uuid[16]) {
    Mutex::Autolock autoLock(mLock);

if (mPlugin != NULL) {
        return -EINVAL;
    }

if (!mFactory || !mFactory->isCryptoSchemeSupported(uuid)) {
        findFactoryForScheme(uuid);
    }