1 #include "private/dvr/trusted_uids.h"
2 
3 #include <mutex>
4 #include <unordered_map>
5 
6 #include <binder/IPermissionController.h>
7 #include <binder/IServiceManager.h>
8 #include <private/android_filesystem_config.h>
9 #include <utils/String16.h>
10 #include <vr/vr_manager/vr_manager.h>
11 
12 namespace android {
13 namespace dvr {
14 
IsTrustedUid(uid_t uid,bool use_cache)15 bool IsTrustedUid(uid_t uid, bool use_cache) {
16   static std::unordered_map<uid_t, bool> uid_cache;
17   static std::mutex uid_cache_mutex;
18 
19   // Whitelist requests from the system UID.
20   // These are already whitelisted by the permission service, but it might not
21   // be available if the ActivityManagerService is up during boot.
22   // This ensures the correct result for system services while booting up.
23   if (uid == AID_SYSTEM)
24     return true;
25 
26   std::lock_guard<std::mutex> lock(uid_cache_mutex);
27 
28   if (use_cache) {
29     auto it = uid_cache.find(uid);
30     if (it != uid_cache.end())
31       return it->second;
32   }
33 
34   sp<IBinder> binder = defaultServiceManager()->getService(String16("permission"));
35   if (binder == 0) {
36     ALOGW("Could not access permission service");
37     return false;
38   }
39 
40   // Note: we ignore the pid because it's only used to automatically reply
41   // true if the caller is the Activity Manager Service.
42   bool trusted = interface_cast<IPermissionController>(binder)->checkPermission(
43       String16("android.permission.RESTRICTED_VR_ACCESS"), -1, uid);
44 
45   // Cache the information for this uid to avoid future Java calls.
46   uid_cache[uid] = trusted;
47   return trusted;
48 }
49 
50 }  // namespace dvr
51 }  // namespace android
52