1/*
2 * Copyright (C) 2017 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 "CasManager"
19#include "CasManager.h"
20
21#include <android/media/ICas.h>
22#include <android/media/IDescrambler.h>
23#include <android/media/IMediaCasService.h>
24#include <binder/IServiceManager.h>
25#include <media/stagefright/foundation/ABitReader.h>
26#include <utils/Log.h>
27
28namespace android {
29using binder::Status;
30
31struct ATSParser::CasManager::ProgramCasManager : public RefBase {
32    ProgramCasManager(unsigned programNumber, const CADescriptor &descriptor);
33    ProgramCasManager(unsigned programNumber);
34
35    bool addStream(unsigned elementaryPID, const CADescriptor &descriptor);
36
37    status_t setMediaCas(const sp<ICas> &cas, PidToSessionMap &sessionMap);
38
39    bool getCasSession(unsigned elementaryPID,
40            sp<IDescrambler> *descrambler, std::vector<uint8_t> *sessionId) const;
41
42    void closeAllSessions(const sp<ICas>& cas);
43
44private:
45    struct CasSession {
46        CasSession() {}
47        CasSession(const CADescriptor &descriptor) :
48            mCADescriptor(descriptor) {}
49
50        CADescriptor mCADescriptor;
51        std::vector<uint8_t> mSessionId;
52        sp<IDescrambler> mDescrambler;
53    };
54    status_t initSession(
55            const sp<ICas>& cas,
56            PidToSessionMap &sessionMap,
57            CasSession *session);
58    void closeSession(const sp<ICas>& cas, const CasSession &casSession);
59
60    unsigned mProgramNumber;
61    bool mHasProgramCas;
62    CasSession mProgramCas;
63    KeyedVector<unsigned, CasSession> mStreamPidToCasMap;
64};
65
66ATSParser::CasManager::ProgramCasManager::ProgramCasManager(
67        unsigned programNumber, const CADescriptor &descriptor) :
68    mProgramNumber(programNumber),
69    mHasProgramCas(true),
70    mProgramCas(descriptor) {}
71
72ATSParser::CasManager::ProgramCasManager::ProgramCasManager(
73        unsigned programNumber) :
74    mProgramNumber(programNumber),
75    mHasProgramCas(false) {}
76
77bool ATSParser::CasManager::ProgramCasManager::addStream(
78        unsigned elementaryPID, const CADescriptor &descriptor) {
79    ssize_t index = mStreamPidToCasMap.indexOfKey(elementaryPID);
80    if (index >= 0) {
81        return false;
82    }
83    ALOGV("addStream: program=%d, elementaryPID=%d, CA_system_ID=0x%x",
84            mProgramNumber, elementaryPID, descriptor.mSystemID);
85    mStreamPidToCasMap.add(elementaryPID, CasSession(descriptor));
86    return true;
87}
88
89status_t ATSParser::CasManager::ProgramCasManager::setMediaCas(
90        const sp<ICas> &cas, PidToSessionMap &sessionMap) {
91    if (mHasProgramCas) {
92        return initSession(cas, sessionMap, &mProgramCas);
93    }
94    // TODO: share session among streams that has identical CA_descriptors.
95    // For now, we open one session for each stream that has CA_descriptor.
96    for (size_t index = 0; index < mStreamPidToCasMap.size(); index++) {
97        status_t err = initSession(
98                cas, sessionMap, &mStreamPidToCasMap.editValueAt(index));
99        if (err != OK) {
100            return err;
101        }
102    }
103    return OK;
104}
105
106bool ATSParser::CasManager::ProgramCasManager::getCasSession(
107        unsigned elementaryPID, sp<IDescrambler> *descrambler,
108        std::vector<uint8_t> *sessionId) const {
109    if (mHasProgramCas) {
110        *descrambler = mProgramCas.mDescrambler;
111        *sessionId = mProgramCas.mSessionId;
112        return true;
113    }
114    ssize_t index = mStreamPidToCasMap.indexOfKey(elementaryPID);
115    if (index < 0) {
116        return false;
117    }
118
119    *descrambler = mStreamPidToCasMap[index].mDescrambler;
120    *sessionId = mStreamPidToCasMap[index].mSessionId;
121    return true;
122}
123
124status_t ATSParser::CasManager::ProgramCasManager::initSession(
125         const sp<ICas>& cas,
126         PidToSessionMap &sessionMap,
127         CasSession *session) {
128    sp<IServiceManager> sm = defaultServiceManager();
129    sp<IBinder> casServiceBinder = sm->getService(String16("media.cas"));
130    sp<IMediaCasService> casService =
131            interface_cast<IMediaCasService>(casServiceBinder);
132
133    if (casService == NULL) {
134        ALOGE("Cannot obtain IMediaCasService");
135        return NO_INIT;
136    }
137
138    sp<IDescrambler> descrambler;
139    std::vector<uint8_t> sessionId;
140    const CADescriptor &descriptor = session->mCADescriptor;
141
142    Status status = cas->openSession(&sessionId);
143    if (!status.isOk()) {
144        ALOGE("Failed to open session: exception=%d, error=%d",
145                status.exceptionCode(), status.serviceSpecificErrorCode());
146        goto l_fail;
147    }
148
149    cas->setSessionPrivateData(sessionId, descriptor.mPrivateData);
150    if (!status.isOk()) {
151        ALOGE("Failed to set private data: exception=%d, error=%d",
152                status.exceptionCode(), status.serviceSpecificErrorCode());
153        goto l_fail;
154    }
155
156    status = casService->createDescrambler(descriptor.mSystemID, &descrambler);
157    if (!status.isOk() || descrambler == NULL) {
158        ALOGE("Failed to create descrambler: : exception=%d, error=%d",
159                status.exceptionCode(), status.serviceSpecificErrorCode());
160        goto l_fail;
161    }
162
163    status = descrambler->setMediaCasSession(sessionId);
164    if (!status.isOk()) {
165        ALOGE("Failed to init descrambler: : exception=%d, error=%d",
166                status.exceptionCode(), status.serviceSpecificErrorCode());
167        goto l_fail;
168    }
169
170    session->mSessionId = sessionId;
171    session->mDescrambler = descrambler;
172    sessionMap.add(descriptor.mPID, sessionId);
173
174    return OK;
175
176l_fail:
177    if (!sessionId.empty()) {
178        cas->closeSession(sessionId);
179    }
180    if (descrambler != NULL) {
181        descrambler->release();
182    }
183    return NO_INIT;
184}
185
186void ATSParser::CasManager::ProgramCasManager::closeSession(
187        const sp<ICas>& cas, const CasSession &casSession) {
188    if (casSession.mDescrambler != NULL) {
189        casSession.mDescrambler->release();
190    }
191    if (!casSession.mSessionId.empty()) {
192        cas->closeSession(casSession.mSessionId);
193    }
194}
195
196void ATSParser::CasManager::ProgramCasManager::closeAllSessions(
197        const sp<ICas>& cas) {
198    if (mHasProgramCas) {
199        closeSession(cas, mProgramCas);
200    }
201    for (size_t index = 0; index < mStreamPidToCasMap.size(); index++) {
202        closeSession(cas, mStreamPidToCasMap.editValueAt(index));
203    }
204}
205
206////////////////////////////////////////////////////////////////////////////////
207
208ATSParser::CasManager::CasManager() : mSystemId(-1) {}
209
210ATSParser::CasManager::~CasManager() {
211    // Explictly close the sessions opened by us, since the CAS object is owned
212    // by the app and may not go away after the parser is destroyed, and the app
213    // may not have information about the sessions.
214    if (mICas != NULL) {
215        for (size_t index = 0; index < mProgramCasMap.size(); index++) {
216            mProgramCasMap.editValueAt(index)->closeAllSessions(mICas);
217        }
218    }
219}
220
221bool ATSParser::CasManager::setSystemId(int32_t CA_system_ID) {
222    if (mSystemId == -1) {
223        // Verify the CA_system_ID is within range on the first program
224        if (CA_system_ID < 0 || CA_system_ID > 0xffff) {
225            ALOGE("Invalid CA_system_id: %d", CA_system_ID);
226            return false;
227        }
228        mSystemId = CA_system_ID;
229    } else if (mSystemId != CA_system_ID) {
230        // All sessions need to be under the same CA system
231        ALOGE("Multiple CA systems not allowed: %d vs %d",
232                mSystemId, CA_system_ID);
233        return false;
234    }
235    return true;
236}
237
238status_t ATSParser::CasManager::setMediaCas(const sp<ICas> &cas) {
239    if (cas == NULL) {
240        ALOGE("setMediaCas: received NULL object");
241        return BAD_VALUE;
242    }
243    if (mICas != NULL) {
244        ALOGW("setMediaCas: already set");
245        return ALREADY_EXISTS;
246    }
247    for (size_t index = 0; index < mProgramCasMap.size(); index++) {
248        status_t err;
249        if ((err = mProgramCasMap.editValueAt(
250                index)->setMediaCas(cas, mCAPidToSessionIdMap)) != OK) {
251            return err;
252        }
253    }
254    mICas = cas;
255    return OK;
256}
257
258bool ATSParser::CasManager::addProgram(
259        unsigned programNumber, const CADescriptor &descriptor) {
260    if (!setSystemId(descriptor.mSystemID)) {
261        return false;
262    }
263
264    ssize_t index = mProgramCasMap.indexOfKey(programNumber);
265    if (index < 0) {
266        ALOGV("addProgram: programNumber=%d, CA_system_ID=0x%x",
267                programNumber, descriptor.mSystemID);
268        mProgramCasMap.add(programNumber,
269                new ProgramCasManager(programNumber, descriptor));
270        mCAPidSet.insert(descriptor.mPID);
271    }
272    return true;
273}
274
275bool ATSParser::CasManager::addStream(
276        unsigned programNumber, unsigned elementaryPID,
277        const CADescriptor &descriptor) {
278    if (!setSystemId(descriptor.mSystemID)) {
279        return false;
280    }
281
282    ssize_t index = mProgramCasMap.indexOfKey(programNumber);
283    sp<ProgramCasManager> programCasManager;
284    if (index < 0) {
285        ALOGV("addProgram (no CADescriptor): programNumber=%d", programNumber);
286        programCasManager = new ProgramCasManager(programNumber);
287        mProgramCasMap.add(programNumber, programCasManager);
288    } else {
289        programCasManager = mProgramCasMap.editValueAt(index);
290    }
291    if (programCasManager->addStream(elementaryPID, descriptor)) {
292        mCAPidSet.insert(descriptor.mPID);
293    }
294    return true;
295}
296
297bool ATSParser::CasManager::getCasInfo(
298        unsigned programNumber, unsigned elementaryPID,
299        int32_t *systemId, sp<IDescrambler> *descrambler,
300        std::vector<uint8_t> *sessionId) const {
301    ssize_t index = mProgramCasMap.indexOfKey(programNumber);
302    if (index < 0) {
303        return false;
304    }
305    *systemId = mSystemId;
306    return mProgramCasMap[index]->getCasSession(
307            elementaryPID, descrambler, sessionId);
308}
309
310bool ATSParser::CasManager::isCAPid(unsigned pid) {
311    return mCAPidSet.find(pid) != mCAPidSet.end();
312}
313
314bool ATSParser::CasManager::parsePID(ABitReader *br, unsigned pid) {
315    ssize_t index = mCAPidToSessionIdMap.indexOfKey(pid);
316    if (index < 0) {
317        return false;
318    }
319    MediaCas::ParcelableCasData ecm(br->data(), br->numBitsLeft() / 8);
320    Status status = mICas->processEcm(mCAPidToSessionIdMap[index], ecm);
321    if (!status.isOk()) {
322        ALOGE("Failed to process ECM: exception=%d, error=%d",
323                status.exceptionCode(), status.serviceSpecificErrorCode());
324    }
325    return true; // handled
326}
327
328}  // namespace android
329