1 /*
2  * Copyright (C) 2024 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 #define LOG_TAG "ApexSupport"
17 
18 #include "android/apexsupport.h"
19 
20 #include <dlfcn.h>
21 
22 #include <string>
23 
24 #include <android/dlext.h>
25 #include <log/log.h>
26 
27 extern "C" android_namespace_t *android_get_exported_namespace(const char *);
28 
AApexSupport_loadLibrary(const char * _Nonnull name,const char * _Nonnull apexName,int flag)29 void *AApexSupport_loadLibrary(const char *_Nonnull name,
30                                const char *_Nonnull apexName, int flag) {
31   // convert the apex name into the linker namespace name
32   std::string namespaceName = apexName;
33   std::replace(namespaceName.begin(), namespaceName.end(), '.', '_');
34 
35   android_namespace_t *ns =
36       android_get_exported_namespace(namespaceName.c_str());
37   if (ns == nullptr) {
38     ALOGE("Could not find namespace for %s APEX. Is it visible?", apexName);
39     return nullptr;
40   }
41 
42   const android_dlextinfo dlextinfo = {
43       .flags = ANDROID_DLEXT_USE_NAMESPACE,
44       .library_namespace = ns,
45   };
46   void *handle = android_dlopen_ext(name, flag, &dlextinfo);
47   if (!handle) {
48     ALOGE("Could not load %s: %s", name, dlerror());
49     return nullptr;
50   }
51   return handle;
52 }
53