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