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      1 /*
      2  * Copyright (C) 2015 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_NDEBUG 0
     18 #define LOG_TAG "DrmSessionManager"
     19 #include <utils/Log.h>
     20 
     21 #include <binder/IPCThreadState.h>
     22 #include <binder/IProcessInfoService.h>
     23 #include <binder/IServiceManager.h>
     24 #include <media/DrmSessionManager.h>
     25 #include <media/DrmSessionClientInterface.h>
     26 #include <media/stagefright/ProcessInfo.h>
     27 #include <unistd.h>
     28 #include <utils/String8.h>
     29 
     30 namespace android {
     31 
     32 static String8 GetSessionIdString(const Vector<uint8_t> &sessionId) {
     33     String8 sessionIdStr;
     34     for (size_t i = 0; i < sessionId.size(); ++i) {
     35         sessionIdStr.appendFormat("%u ", sessionId[i]);
     36     }
     37     return sessionIdStr;
     38 }
     39 
     40 bool isEqualSessionId(const Vector<uint8_t> &sessionId1, const Vector<uint8_t> &sessionId2) {
     41     if (sessionId1.size() != sessionId2.size()) {
     42         return false;
     43     }
     44     for (size_t i = 0; i < sessionId1.size(); ++i) {
     45         if (sessionId1[i] != sessionId2[i]) {
     46             return false;
     47         }
     48     }
     49     return true;
     50 }
     51 
     52 sp<DrmSessionManager> DrmSessionManager::Instance() {
     53     static sp<DrmSessionManager> drmSessionManager = new DrmSessionManager();
     54     return drmSessionManager;
     55 }
     56 
     57 DrmSessionManager::DrmSessionManager()
     58     : mProcessInfo(new ProcessInfo()),
     59       mTime(0) {}
     60 
     61 DrmSessionManager::DrmSessionManager(sp<ProcessInfoInterface> processInfo)
     62     : mProcessInfo(processInfo),
     63       mTime(0) {}
     64 
     65 DrmSessionManager::~DrmSessionManager() {}
     66 
     67 void DrmSessionManager::addSession(
     68         int pid, sp<DrmSessionClientInterface> drm, const Vector<uint8_t> &sessionId) {
     69     ALOGV("addSession(pid %d, drm %p, sessionId %s)", pid, drm.get(),
     70             GetSessionIdString(sessionId).string());
     71 
     72     Mutex::Autolock lock(mLock);
     73     SessionInfo info;
     74     info.drm = drm;
     75     info.sessionId = sessionId;
     76     info.timeStamp = getTime_l();
     77     ssize_t index = mSessionMap.indexOfKey(pid);
     78     if (index < 0) {
     79         // new pid
     80         SessionInfos infosForPid;
     81         infosForPid.push_back(info);
     82         mSessionMap.add(pid, infosForPid);
     83     } else {
     84         mSessionMap.editValueAt(index).push_back(info);
     85     }
     86 }
     87 
     88 void DrmSessionManager::useSession(const Vector<uint8_t> &sessionId) {
     89     ALOGV("useSession(%s)", GetSessionIdString(sessionId).string());
     90 
     91     Mutex::Autolock lock(mLock);
     92     for (size_t i = 0; i < mSessionMap.size(); ++i) {
     93         SessionInfos& infos = mSessionMap.editValueAt(i);
     94         for (size_t j = 0; j < infos.size(); ++j) {
     95             SessionInfo& info = infos.editItemAt(j);
     96             if (isEqualSessionId(sessionId, info.sessionId)) {
     97                 info.timeStamp = getTime_l();
     98                 return;
     99             }
    100         }
    101     }
    102 }
    103 
    104 void DrmSessionManager::removeSession(const Vector<uint8_t> &sessionId) {
    105     ALOGV("removeSession(%s)", GetSessionIdString(sessionId).string());
    106 
    107     Mutex::Autolock lock(mLock);
    108     for (size_t i = 0; i < mSessionMap.size(); ++i) {
    109         SessionInfos& infos = mSessionMap.editValueAt(i);
    110         for (size_t j = 0; j < infos.size(); ++j) {
    111             if (isEqualSessionId(sessionId, infos[j].sessionId)) {
    112                 infos.removeAt(j);
    113                 return;
    114             }
    115         }
    116     }
    117 }
    118 
    119 void DrmSessionManager::removeDrm(sp<DrmSessionClientInterface> drm) {
    120     ALOGV("removeDrm(%p)", drm.get());
    121 
    122     Mutex::Autolock lock(mLock);
    123     bool found = false;
    124     for (size_t i = 0; i < mSessionMap.size(); ++i) {
    125         SessionInfos& infos = mSessionMap.editValueAt(i);
    126         for (size_t j = 0; j < infos.size();) {
    127             if (infos[j].drm == drm) {
    128                 ALOGV("removed session (%s)", GetSessionIdString(infos[j].sessionId).string());
    129                 j = infos.removeAt(j);
    130                 found = true;
    131             } else {
    132                 ++j;
    133             }
    134         }
    135         if (found) {
    136             break;
    137         }
    138     }
    139 }
    140 
    141 bool DrmSessionManager::reclaimSession(int callingPid) {
    142     ALOGV("reclaimSession(%d)", callingPid);
    143 
    144     sp<DrmSessionClientInterface> drm;
    145     Vector<uint8_t> sessionId;
    146     int lowestPriorityPid;
    147     int lowestPriority;
    148     {
    149         Mutex::Autolock lock(mLock);
    150         int callingPriority;
    151         if (!mProcessInfo->getPriority(callingPid, &callingPriority)) {
    152             return false;
    153         }
    154         if (!getLowestPriority_l(&lowestPriorityPid, &lowestPriority)) {
    155             return false;
    156         }
    157         if (lowestPriority <= callingPriority) {
    158             return false;
    159         }
    160 
    161         if (!getLeastUsedSession_l(lowestPriorityPid, &drm, &sessionId)) {
    162             return false;
    163         }
    164     }
    165 
    166     if (drm == NULL) {
    167         return false;
    168     }
    169 
    170     ALOGV("reclaim session(%s) opened by pid %d",
    171             GetSessionIdString(sessionId).string(), lowestPriorityPid);
    172 
    173     return drm->reclaimSession(sessionId);
    174 }
    175 
    176 int64_t DrmSessionManager::getTime_l() {
    177     return mTime++;
    178 }
    179 
    180 bool DrmSessionManager::getLowestPriority_l(int* lowestPriorityPid, int* lowestPriority) {
    181     int pid = -1;
    182     int priority = -1;
    183     for (size_t i = 0; i < mSessionMap.size(); ++i) {
    184         if (mSessionMap.valueAt(i).size() == 0) {
    185             // no opened session by this process.
    186             continue;
    187         }
    188         int tempPid = mSessionMap.keyAt(i);
    189         int tempPriority;
    190         if (!mProcessInfo->getPriority(tempPid, &tempPriority)) {
    191             // shouldn't happen.
    192             return false;
    193         }
    194         if (pid == -1) {
    195             pid = tempPid;
    196             priority = tempPriority;
    197         } else {
    198             if (tempPriority > priority) {
    199                 pid = tempPid;
    200                 priority = tempPriority;
    201             }
    202         }
    203     }
    204     if (pid != -1) {
    205         *lowestPriorityPid = pid;
    206         *lowestPriority = priority;
    207     }
    208     return (pid != -1);
    209 }
    210 
    211 bool DrmSessionManager::getLeastUsedSession_l(
    212         int pid, sp<DrmSessionClientInterface>* drm, Vector<uint8_t>* sessionId) {
    213     ssize_t index = mSessionMap.indexOfKey(pid);
    214     if (index < 0) {
    215         return false;
    216     }
    217 
    218     int leastUsedIndex = -1;
    219     int64_t minTs = LLONG_MAX;
    220     const SessionInfos& infos = mSessionMap.valueAt(index);
    221     for (size_t j = 0; j < infos.size(); ++j) {
    222         if (leastUsedIndex == -1) {
    223             leastUsedIndex = j;
    224             minTs = infos[j].timeStamp;
    225         } else {
    226             if (infos[j].timeStamp < minTs) {
    227                 leastUsedIndex = j;
    228                 minTs = infos[j].timeStamp;
    229             }
    230         }
    231     }
    232     if (leastUsedIndex != -1) {
    233         *drm = infos[leastUsedIndex].drm;
    234         *sessionId = infos[leastUsedIndex].sessionId;
    235     }
    236     return (leastUsedIndex != -1);
    237 }
    238 
    239 }  // namespace android
    240