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 <cutils/properties.h>
  19 #include "nativebridge/native_bridge.h"
  20
  21 namespace android {
  22
  23 static void *native_handle = nullptr;
  24
  25 static NativeBridgeCallbacks *get_callbacks()
  26 {
  27     static NativeBridgeCallbacks *callbacks = nullptr;
  28
  29     if (!callbacks) {
  30         const char *libnb = "/system/"
  31 #ifdef __LP64__
  32                 "lib64/arm64/"
  33 #else
  34                 "lib/arm/"
  35 #endif
  36                 "libhoudini.so";
  37         if (!native_handle) {
  38             native_handle = dlopen(libnb, RTLD_LAZY);
  39             if (!native_handle) {
  40                 ALOGE("Unable to open %s", libnb);
  41                 return nullptr;
  42             }
  43         }
  44         callbacks = reinterpret_cast<NativeBridgeCallbacks *>(dlsym(native_handle, "NativeBridgeItf"));
  45     }
  46     return callbacks;
  47 }
  48
  49 // NativeBridgeCallbacks implementations
  50 static bool native_bridge2_initialize(const NativeBridgeRuntimeCallbacks *art_cbs,
  51                                       const char *app_code_cache_dir,
  52                                       const char *isa)
  53 {
  54     ALOGV("enter native_bridge2_initialize %s %s", app_code_cache_dir, isa);
  55     if (property_get_bool("persist.sys.nativebridge", 0)) {
  56         if (NativeBridgeCallbacks *cb = get_callbacks()) {
  57             return cb->initialize(art_cbs, app_code_cache_dir, isa);
  58         }
  59     } else {
  60         ALOGW("Native bridge is disabled");
  61     }
  62     return false;
  63 }
  64
  65 static void *native_bridge2_loadLibrary(const char *libpath, int flag)
  66 {
  67     ALOGV("enter native_bridge2_loadLibrary %s", libpath);
  68     NativeBridgeCallbacks *cb = get_callbacks();
  69     return cb ? cb->loadLibrary(libpath, flag) : nullptr;
  70 }
  71
  72 static void *native_bridge2_getTrampoline(void *handle, const char *name,
  73                                           const char* shorty, uint32_t len)
  74 {
  75     ALOGV("enter native_bridge2_getTrampoline %s", name);
  76     NativeBridgeCallbacks *cb = get_callbacks();
  77     return cb ? cb->getTrampoline(handle, name, shorty, len) : nullptr;
  78 }
  79
  80 static bool native_bridge2_isSupported(const char *libpath)
  81 {
  82     ALOGV("enter native_bridge2_isSupported %s", libpath);
  83     NativeBridgeCallbacks *cb = get_callbacks();
  84     return cb ? cb->isSupported(libpath) : false;
  85 }
  86
  87 static const struct NativeBridgeRuntimeValues *native_bridge2_getAppEnv(const char *abi)
  88 {
  89     ALOGV("enter native_bridge2_getAppEnv %s", abi);
  90     NativeBridgeCallbacks *cb = get_callbacks();
  91     return cb ? cb->getAppEnv(abi) : nullptr;
  92 }
  93
  94 static bool native_bridge2_is_compatible_compatible_with(uint32_t version)
  95 {
  96     // For testing, allow 1 and 2, but disallow 3+.
  97     return version <= 2;
  98 }
  99
 100 static NativeBridgeSignalHandlerFn native_bridge2_get_signal_handler(int signal)
 101 {
 102     ALOGV("enter native_bridge2_getAppEnv %d", signal);
 103     NativeBridgeCallbacks *cb = get_callbacks();
 104     return cb ? cb->getSignalHandler(signal) : nullptr;
 105 }
 106
 107 static void __attribute__ ((destructor)) on_dlclose()
 108 {
 109     if (native_handle) {
 110         dlclose(native_handle);
 111         native_handle = nullptr;
 112     }
 113 }
 114
 115 extern "C" {
 116
 117 NativeBridgeCallbacks NativeBridgeItf = {
 118     .version = 2,
 119     .initialize = &native_bridge2_initialize,
 120     .loadLibrary = &native_bridge2_loadLibrary,
 121     .getTrampoline = &native_bridge2_getTrampoline,
 122     .isSupported = &native_bridge2_isSupported,
 123     .getAppEnv = &native_bridge2_getAppEnv,
 124     .isCompatibleWith = &native_bridge2_is_compatible_compatible_with,
 125     .getSignalHandler = &native_bridge2_get_signal_handler,
 126 };
 127
 128 } // extern "C"
 129 } // namespace android