是否可以使用 C++ Binder API 在两个非特权进程之间进行通信?
我发现的所有示例(例如https://github.com/mcr/Android-HelloWorldService)都依赖于注册服务ServiceManager->addService()
,在非 root 手机上执行时会引发以下错误:
E/ServiceManager﹕ add_service('my.test.service',0x48) uid=2000 - PERMISSION DENIED
是否可以使用 C++ Binder API 在两个非特权进程之间进行通信?
我发现的所有示例(例如https://github.com/mcr/Android-HelloWorldService)都依赖于注册服务ServiceManager->addService()
,在非 root 手机上执行时会引发以下错误:
E/ServiceManager﹕ add_service('my.test.service',0x48) uid=2000 - PERMISSION DENIED
在文件 frameworks/native/cmds/servicemanager/service_manager.c 中的 AOSP(Android 开源项目)中,您可以找到以下方法:
int svc_can_register(uid_t uid, const uint16_t *name)
{
size_t n;
if ((uid == 0) || (uid == AID_SYSTEM))
return 1;
for (n = 0; n < sizeof(allowed) / sizeof(allowed[0]); n++)
if ((uid == allowed[n].uid) && str16eq(name, allowed[n].name))
return 1;
return 0;
}
还有一点:
/* TODO:
* These should come from a config file or perhaps be
* based on some namespace rules of some sort (media
* uid can register media.*, etc)
*/
static struct {
uid_t uid;
const char *name;
} allowed[] = {
{ AID_MEDIA, "media.audio_flinger" },
{ AID_MEDIA, "media.log" },
{ AID_MEDIA, "media.player" },
{ AID_MEDIA, "media.camera" },
{ AID_MEDIA, "media.audio_policy" },
{ AID_DRM, "drm.drmManager" },
{ AID_NFC, "nfc" },
{ AID_BLUETOOTH, "bluetooth" },
{ AID_RADIO, "radio.phone" },
{ AID_RADIO, "radio.sms" },
{ AID_RADIO, "radio.phonesubinfo" },
{ AID_RADIO, "radio.simphonebook" },
/* TODO: remove after phone services are updated: */
{ AID_RADIO, "phone" },
{ AID_RADIO, "sip" },
{ AID_RADIO, "isms" },
{ AID_RADIO, "iphonesubinfo" },
{ AID_RADIO, "simphonebook" },
{ AID_MEDIA, "common_time.clock" },
{ AID_MEDIA, "common_time.config" },
{ AID_KEYSTORE, "android.security.keystore" },
};
再往下:
if (!svc_can_register(uid, s)) {
ALOGE("add_service('%s',%x) uid=%d - PERMISSION DENIED\n",
str8(s), handle, uid);
return -1;
}
结论:/system/bin/servicemanager 中的系统二进制文件不允许。(出于安全原因)可能的解决方案: