nativebridge/src/libnb.cpp

   1 /*
   2  * Copyright (C) 2015 The Android-x86 Open Source Project
   3  *
   4  * by Chih-Wei Huang <cwhuang@linux.org.tw>
   5  *
   6  * Licensed under the GNU General Public License Version 2 or later.
   7  * You may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  * http://www.gnu.org/licenses/gpl.html
  11  *
  12  */
  13
  14 #define LOG_TAG "libnb"
  15
  16 #include <dlfcn.h>
  17 #include <cutils/log.h>
  18 #include "nativebridge/native_bridge.h"
  19
  20 namespace android {
  21
  22 static void *native_handle = nullptr;
  23
  24 static NativeBridgeCallbacks *get_callbacks()
  25 {
  26     static NativeBridgeCallbacks *callbacks = nullptr;
  27
  28     if (!callbacks) {
  29         const char *libnb = "/system/"
  30 #ifdef __LP64__
  31                 "lib64/arm64/"
  32 #else
  33                 "lib/arm/"
  34 #endif
  35                 "libhoudini.so";
  36         if (!native_handle) {
  37             native_handle = dlopen(libnb, RTLD_LAZY);
  38             if (!native_handle) {
  39                 ALOGE("Unable to open %s", libnb);
  40                 return nullptr;
  41             }
  42         }
  43         callbacks = reinterpret_cast<NativeBridgeCallbacks *>(dlsym(native_handle, "NativeBridgeItf"));
  44     }
  45     return callbacks;
  46 }
  47
  48 // NativeBridgeCallbacks implementations
  49 static bool native_bridge2_initialize(const NativeBridgeRuntimeCallbacks *art_cbs,
  50                                       const char *app_code_cache_dir,
  51                                       const char *isa)
  52 {
  53     ALOGV("enter native_bridge2_initialize %s %s", app_code_cache_dir, isa);
  54     NativeBridgeCallbacks *cb = get_callbacks();
  55     return cb ? cb->initialize(art_cbs, app_code_cache_dir, isa) : false;
  56 }
  57
  58 static void *native_bridge2_loadLibrary(const char *libpath, int flag)
  59 {
  60     ALOGV("enter native_bridge2_loadLibrary %s", libpath);
  61     NativeBridgeCallbacks *cb = get_callbacks();
  62     return cb ? cb->loadLibrary(libpath, flag) : nullptr;
  63 }
  64
  65 static void *native_bridge2_getTrampoline(void *handle, const char *name,
  66                                           const char* shorty, uint32_t len)
  67 {
  68     ALOGV("enter native_bridge2_getTrampoline %s", name);
  69     NativeBridgeCallbacks *cb = get_callbacks();
  70     return cb ? cb->getTrampoline(handle, name, shorty, len) : nullptr;
  71 }
  72
  73 static bool native_bridge2_isSupported(const char *libpath)
  74 {
  75     ALOGV("enter native_bridge2_isSupported %s", libpath);
  76     NativeBridgeCallbacks *cb = get_callbacks();
  77     return cb ? cb->isSupported(libpath) : false;
  78 }
  79
  80 static const struct NativeBridgeRuntimeValues *native_bridge2_getAppEnv(const char *abi)
  81 {
  82     ALOGV("enter native_bridge2_getAppEnv %s", abi);
  83     NativeBridgeCallbacks *cb = get_callbacks();
  84     return cb ? cb->getAppEnv(abi) : nullptr;
  85 }
  86
  87 static bool native_bridge2_is_compatible_compatible_with(uint32_t version)
  88 {
  89     // For testing, allow 1 and 2, but disallow 3+.
  90     return version <= 2;
  91 }
  92
  93 static NativeBridgeSignalHandlerFn native_bridge2_get_signal_handler(int signal)
  94 {
  95     ALOGV("enter native_bridge2_getAppEnv %d", signal);
  96     NativeBridgeCallbacks *cb = get_callbacks();
  97     return cb ? cb->getSignalHandler(signal) : nullptr;
  98 }
  99
 100 static void __attribute__ ((destructor)) on_dlclose()
 101 {
 102     if (native_handle) {
 103         dlclose(native_handle);
 104         native_handle = nullptr;
 105     }
 106 }
 107
 108 extern "C" {
 109
 110 NativeBridgeCallbacks NativeBridgeItf = {
 111     version: 2,
 112     initialize: &native_bridge2_initialize,
 113     loadLibrary: &native_bridge2_loadLibrary,
 114     getTrampoline: &native_bridge2_getTrampoline,
 115     isSupported: &native_bridge2_isSupported,
 116     getAppEnv: &native_bridge2_getAppEnv,
 117     isCompatibleWith: &native_bridge2_is_compatible_compatible_with,
 118     getSignalHandler: &native_bridge2_get_signal_handler,
 119 };
 120
 121 } // extern "C"
 122 } // namespace android