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 #ifndef ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_
18 #define ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_
19 
20 #include <dirent.h>
21 #include <dlfcn.h>
22 #include "SharedLibrary.h"
23 #include <utils/KeyedVector.h>
24 #include <utils/Mutex.h>
25 #include <media/cas/CasAPI.h>
26 
27 using namespace std;
28 
29 namespace android {
30 namespace hardware {
31 namespace cas {
32 namespace V1_0 {
33 namespace implementation {
34 
35 template <class T>
36 class FactoryLoader {
37 public:
FactoryLoader(const char * name)38     FactoryLoader(const char *name) :
39         mFactory(NULL), mCreateFactoryFuncName(name) {}
40 
~FactoryLoader()41     virtual ~FactoryLoader() { closeFactory(); }
42 
43     bool findFactoryForScheme(
44             int32_t CA_system_id,
45             sp<SharedLibrary> *library = NULL,
46             T** factory = NULL);
47 
48     bool enumeratePlugins(vector<HidlCasPluginDescriptor>* results);
49 
50 private:
51     typedef T*(*CreateFactoryFunc)();
52 
53     Mutex mMapLock;
54     T* mFactory;
55     const char *mCreateFactoryFuncName;
56     sp<SharedLibrary> mLibrary;
57     KeyedVector<int32_t, String8> mCASystemIdToLibraryPathMap;
58     KeyedVector<String8, wp<SharedLibrary> > mLibraryPathToOpenLibraryMap;
59 
60     bool loadFactoryForSchemeFromPath(
61             const String8 &path,
62             int32_t CA_system_id,
63             sp<SharedLibrary> *library,
64             T** factory);
65 
66     bool queryPluginsFromPath(
67             const String8 &path,
68             vector<HidlCasPluginDescriptor>* results);
69 
70     bool openFactory(const String8 &path);
71     void closeFactory();
72 };
73 
74 template <class T>
findFactoryForScheme(int32_t CA_system_id,sp<SharedLibrary> * library,T ** factory)75 bool FactoryLoader<T>::findFactoryForScheme(
76         int32_t CA_system_id, sp<SharedLibrary> *library, T** factory) {
77     if (library != NULL) {
78         library->clear();
79     }
80     if (factory != NULL) {
81         *factory = NULL;
82     }
83 
84     Mutex::Autolock autoLock(mMapLock);
85 
86     // first check cache
87     ssize_t index = mCASystemIdToLibraryPathMap.indexOfKey(CA_system_id);
88     if (index >= 0) {
89         return loadFactoryForSchemeFromPath(
90                 mCASystemIdToLibraryPathMap[index],
91                 CA_system_id, library, factory);
92     }
93 
94     // no luck, have to search
95     String8 dirPath("/vendor/lib/mediacas");
96     DIR* pDir = opendir(dirPath.string());
97 
98     if (pDir == NULL) {
99         ALOGE("Failed to open plugin directory %s", dirPath.string());
100         return false;
101     }
102 
103     struct dirent* pEntry;
104     while ((pEntry = readdir(pDir))) {
105         String8 pluginPath = dirPath + "/" + pEntry->d_name;
106         if (pluginPath.getPathExtension() == ".so") {
107             if (loadFactoryForSchemeFromPath(
108                     pluginPath, CA_system_id, library, factory)) {
109                 mCASystemIdToLibraryPathMap.add(CA_system_id, pluginPath);
110                 closedir(pDir);
111 
112                 return true;
113             }
114         }
115     }
116 
117     closedir(pDir);
118 
119     ALOGE("Failed to find plugin");
120     return false;
121 }
122 
123 template <class T>
enumeratePlugins(vector<HidlCasPluginDescriptor> * results)124 bool FactoryLoader<T>::enumeratePlugins(
125         vector<HidlCasPluginDescriptor>* results) {
126     ALOGI("enumeratePlugins");
127 
128     results->clear();
129 
130     String8 dirPath("/vendor/lib/mediacas");
131     DIR* pDir = opendir(dirPath.string());
132 
133     if (pDir == NULL) {
134         ALOGE("Failed to open plugin directory %s", dirPath.string());
135         return false;
136     }
137 
138     Mutex::Autolock autoLock(mMapLock);
139 
140     struct dirent* pEntry;
141     while ((pEntry = readdir(pDir))) {
142         String8 pluginPath = dirPath + "/" + pEntry->d_name;
143         if (pluginPath.getPathExtension() == ".so") {
144             queryPluginsFromPath(pluginPath, results);
145         }
146     }
147     return true;
148 }
149 
150 template <class T>
loadFactoryForSchemeFromPath(const String8 & path,int32_t CA_system_id,sp<SharedLibrary> * library,T ** factory)151 bool FactoryLoader<T>::loadFactoryForSchemeFromPath(
152         const String8 &path, int32_t CA_system_id,
153         sp<SharedLibrary> *library, T** factory) {
154     closeFactory();
155 
156     if (!openFactory(path) || !mFactory->isSystemIdSupported(CA_system_id)) {
157         closeFactory();
158         return false;
159     }
160 
161     if (library != NULL) {
162         *library = mLibrary;
163     }
164     if (factory != NULL) {
165         *factory = mFactory;
166     }
167     return true;
168 }
169 
170 template <class T>
queryPluginsFromPath(const String8 & path,vector<HidlCasPluginDescriptor> * results)171 bool FactoryLoader<T>::queryPluginsFromPath(
172         const String8 &path, vector<HidlCasPluginDescriptor>* results) {
173     closeFactory();
174 
175     vector<CasPluginDescriptor> descriptors;
176     if (!openFactory(path) || mFactory->queryPlugins(&descriptors) != OK) {
177         closeFactory();
178         return false;
179     }
180 
181     for (auto it = descriptors.begin(); it != descriptors.end(); it++) {
182         results->push_back( HidlCasPluginDescriptor {
183                 .caSystemId = it->CA_system_id,
184                 .name = it->name.c_str()});
185     }
186     return true;
187 }
188 
189 template <class T>
openFactory(const String8 & path)190 bool FactoryLoader<T>::openFactory(const String8 &path) {
191     // get strong pointer to open shared library
192     ssize_t index = mLibraryPathToOpenLibraryMap.indexOfKey(path);
193     if (index >= 0) {
194         mLibrary = mLibraryPathToOpenLibraryMap[index].promote();
195     } else {
196         index = mLibraryPathToOpenLibraryMap.add(path, NULL);
197     }
198 
199     if (!mLibrary.get()) {
200         mLibrary = new SharedLibrary(path);
201         if (!*mLibrary) {
202             return false;
203         }
204 
205         mLibraryPathToOpenLibraryMap.replaceValueAt(index, mLibrary);
206     }
207 
208     CreateFactoryFunc createFactory =
209         (CreateFactoryFunc)mLibrary->lookup(mCreateFactoryFuncName);
210     if (createFactory == NULL || (mFactory = createFactory()) == NULL) {
211         return false;
212     }
213     return true;
214 }
215 
216 template <class T>
closeFactory()217 void FactoryLoader<T>::closeFactory() {
218     delete mFactory;
219     mFactory = NULL;
220     mLibrary.clear();
221 }
222 
223 } // namespace implementation
224 } // namespace V1_0
225 } // namespace cas
226 } // namespace hardware
227 } // namespace android
228 
229 #endif // ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_
230