1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #ifndef __ANDROID_VNDK__ 20 21 #include <stdint.h> 22 #include <unistd.h> 23 24 #include <utils/String16.h> 25 #include <utils/Singleton.h> 26 #include <utils/SortedVector.h> 27 28 namespace android { 29 // --------------------------------------------------------------------------- 30 31 /* 32 * PermissionCache caches permission checks for a given uid. 33 * 34 * Currently the cache is not updated when there is a permission change, 35 * for instance when an application is uninstalled. 36 * 37 * IMPORTANT: for the reason stated above, only system permissions are safe 38 * to cache. This restriction may be lifted at a later time. 39 * 40 */ 41 42 class PermissionCache : Singleton<PermissionCache> { 43 struct Entry { 44 String16 name; 45 uid_t uid; 46 bool granted; 47 inline bool operator < (const Entry& e) const { 48 return (uid == e.uid) ? (name < e.name) : (uid < e.uid); 49 } 50 }; 51 mutable Mutex mLock; 52 // we pool all the permission names we see, as many permissions checks 53 // will have identical names 54 SortedVector< String16 > mPermissionNamesPool; 55 // this is our cache per say. it stores pooled names. 56 SortedVector< Entry > mCache; 57 58 // free the whole cache, but keep the permission name pool 59 void purge(); 60 61 status_t check(bool* granted, 62 const String16& permission, uid_t uid) const; 63 64 void cache(const String16& permission, uid_t uid, bool granted); 65 66 public: 67 PermissionCache(); 68 69 static bool checkCallingPermission(const String16& permission); 70 71 static bool checkCallingPermission(const String16& permission, 72 int32_t* outPid, int32_t* outUid); 73 74 static bool checkPermission(const String16& permission, 75 pid_t pid, uid_t uid); 76 77 static void purgeCache(); 78 }; 79 80 // --------------------------------------------------------------------------- 81 } // namespace android 82 83 #else // __ANDROID_VNDK__ 84 #error "This header is not visible to vendors" 85 #endif // __ANDROID_VNDK__ 86