1 /*
2  * Copyright (C) 2009 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 "FileSource"
19 #include <utils/Log.h>
20 
21 #include <media/stagefright/foundation/ADebug.h>
22 #include <media/stagefright/FileSource.h>
23 #include <media/stagefright/Utils.h>
24 #include <private/android_filesystem_config.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <fcntl.h>
30 
31 namespace android {
32 
FileSource(const char * filename)33 FileSource::FileSource(const char *filename)
34     : mFd(-1),
35       mOffset(0),
36       mLength(-1),
37       mName("<null>"),
38       mDecryptHandle(NULL),
39       mDrmManagerClient(NULL),
40       mDrmBufOffset(0),
41       mDrmBufSize(0),
42       mDrmBuf(NULL){
43 
44     if (filename) {
45         mName = String8::format("FileSource(%s)", filename);
46     }
47     ALOGV("%s", filename);
48     mFd = open(filename, O_LARGEFILE | O_RDONLY);
49 
50     if (mFd >= 0) {
51         mLength = lseek64(mFd, 0, SEEK_END);
52     } else {
53         ALOGE("Failed to open file '%s'. (%s)", filename, strerror(errno));
54     }
55 }
56 
FileSource(int fd,int64_t offset,int64_t length)57 FileSource::FileSource(int fd, int64_t offset, int64_t length)
58     : mFd(fd),
59       mOffset(offset),
60       mLength(length),
61       mName("<null>"),
62       mDecryptHandle(NULL),
63       mDrmManagerClient(NULL),
64       mDrmBufOffset(0),
65       mDrmBufSize(0),
66       mDrmBuf(NULL) {
67     ALOGV("fd=%d (%s), offset=%lld, length=%lld",
68             fd, nameForFd(fd).c_str(), (long long) offset, (long long) length);
69 
70     if (mOffset < 0) {
71         mOffset = 0;
72     }
73     if (mLength < 0) {
74         mLength = 0;
75     }
76     if (mLength > INT64_MAX - mOffset) {
77         mLength = INT64_MAX - mOffset;
78     }
79     struct stat s;
80     if (fstat(fd, &s) == 0) {
81         if (mOffset > s.st_size) {
82             mOffset = s.st_size;
83             mLength = 0;
84         }
85         if (mOffset + mLength > s.st_size) {
86             mLength = s.st_size - mOffset;
87         }
88     }
89     if (mOffset != offset || mLength != length) {
90         ALOGW("offset/length adjusted from %lld/%lld to %lld/%lld",
91                 (long long) offset, (long long) length,
92                 (long long) mOffset, (long long) mLength);
93     }
94 
95     mName = String8::format(
96             "FileSource(fd(%s), %lld, %lld)",
97             nameForFd(fd).c_str(),
98             (long long) mOffset,
99             (long long) mLength);
100 
101 }
102 
~FileSource()103 FileSource::~FileSource() {
104     if (mFd >= 0) {
105         ::close(mFd);
106         mFd = -1;
107     }
108 
109     if (mDrmBuf != NULL) {
110         delete[] mDrmBuf;
111         mDrmBuf = NULL;
112     }
113 
114     if (mDecryptHandle != NULL) {
115         // To release mDecryptHandle
116         CHECK(mDrmManagerClient);
117         mDrmManagerClient->closeDecryptSession(mDecryptHandle);
118         mDecryptHandle = NULL;
119     }
120 
121     if (mDrmManagerClient != NULL) {
122         delete mDrmManagerClient;
123         mDrmManagerClient = NULL;
124     }
125 }
126 
initCheck() const127 status_t FileSource::initCheck() const {
128     return mFd >= 0 ? OK : NO_INIT;
129 }
130 
readAt(off64_t offset,void * data,size_t size)131 ssize_t FileSource::readAt(off64_t offset, void *data, size_t size) {
132     if (mFd < 0) {
133         return NO_INIT;
134     }
135 
136     Mutex::Autolock autoLock(mLock);
137 
138     if (mLength >= 0) {
139         if (offset >= mLength) {
140             return 0;  // read beyond EOF.
141         }
142         uint64_t numAvailable = mLength - offset;
143         if ((uint64_t)size > numAvailable) {
144             size = numAvailable;
145         }
146     }
147 
148     if (mDecryptHandle != NULL && DecryptApiType::CONTAINER_BASED
149             == mDecryptHandle->decryptApiType) {
150         return readAtDRM(offset, data, size);
151    } else {
152         off64_t result = lseek64(mFd, offset + mOffset, SEEK_SET);
153         if (result == -1) {
154             ALOGE("seek to %lld failed", (long long)(offset + mOffset));
155             return UNKNOWN_ERROR;
156         }
157 
158         return ::read(mFd, data, size);
159     }
160 }
161 
getSize(off64_t * size)162 status_t FileSource::getSize(off64_t *size) {
163     Mutex::Autolock autoLock(mLock);
164 
165     if (mFd < 0) {
166         return NO_INIT;
167     }
168 
169     *size = mLength;
170 
171     return OK;
172 }
173 
DrmInitialization(const char * mime)174 sp<DecryptHandle> FileSource::DrmInitialization(const char *mime) {
175     if (getuid() == AID_MEDIA_EX) return nullptr; // no DRM in media extractor
176     if (mDrmManagerClient == NULL) {
177         mDrmManagerClient = new DrmManagerClient();
178     }
179 
180     if (mDrmManagerClient == NULL) {
181         return NULL;
182     }
183 
184     if (mDecryptHandle == NULL) {
185         mDecryptHandle = mDrmManagerClient->openDecryptSession(
186                 mFd, mOffset, mLength, mime);
187     }
188 
189     if (mDecryptHandle == NULL) {
190         delete mDrmManagerClient;
191         mDrmManagerClient = NULL;
192     }
193 
194     return mDecryptHandle;
195 }
196 
readAtDRM(off64_t offset,void * data,size_t size)197 ssize_t FileSource::readAtDRM(off64_t offset, void *data, size_t size) {
198     size_t DRM_CACHE_SIZE = 1024;
199     if (mDrmBuf == NULL) {
200         mDrmBuf = new unsigned char[DRM_CACHE_SIZE];
201     }
202 
203     if (mDrmBuf != NULL && mDrmBufSize > 0 && (offset + mOffset) >= mDrmBufOffset
204             && (offset + mOffset + size) <= static_cast<size_t>(mDrmBufOffset + mDrmBufSize)) {
205         /* Use buffered data */
206         memcpy(data, (void*)(mDrmBuf+(offset+mOffset-mDrmBufOffset)), size);
207         return size;
208     } else if (size <= DRM_CACHE_SIZE) {
209         /* Buffer new data */
210         mDrmBufOffset =  offset + mOffset;
211         mDrmBufSize = mDrmManagerClient->pread(mDecryptHandle, mDrmBuf,
212                 DRM_CACHE_SIZE, offset + mOffset);
213         if (mDrmBufSize > 0) {
214             int64_t dataRead = 0;
215             dataRead = size > static_cast<size_t>(mDrmBufSize) ? mDrmBufSize : size;
216             memcpy(data, (void*)mDrmBuf, dataRead);
217             return dataRead;
218         } else {
219             return mDrmBufSize;
220         }
221     } else {
222         /* Too big chunk to cache. Call DRM directly */
223         return mDrmManagerClient->pread(mDecryptHandle, data, size, offset + mOffset);
224     }
225 }
226 
227 /* static */
requiresDrm(int fd,int64_t offset,int64_t length,const char * mime)228 bool FileSource::requiresDrm(int fd, int64_t offset, int64_t length, const char *mime) {
229     std::unique_ptr<DrmManagerClient> drmClient(new DrmManagerClient());
230     sp<DecryptHandle> decryptHandle =
231             drmClient->openDecryptSession(fd, offset, length, mime);
232     bool requiresDrm = false;
233     if (decryptHandle != nullptr) {
234         requiresDrm = decryptHandle->decryptApiType == DecryptApiType::CONTAINER_BASED;
235         drmClient->closeDecryptSession(decryptHandle);
236     }
237     return requiresDrm;
238 }
239 
240 }  // namespace android
241