upload android base code part6

android/system/core/libcutils/multiuser.cpp

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cutils/multiuser.h>
+#include <private/android_filesystem_config.h>
+
+userid_t multiuser_get_user_id(uid_t uid) {
+    return uid / AID_USER_OFFSET;
+}
+
+appid_t multiuser_get_app_id(uid_t uid) {
+    return uid % AID_USER_OFFSET;
+}
+
+uid_t multiuser_get_uid(userid_t user_id, appid_t app_id) {
+    return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET);
+}
+
+gid_t multiuser_get_cache_gid(userid_t user_id, appid_t app_id) {
+    if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
+        return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_CACHE_GID_START);
+    } else {
+        return -1;
+    }
+}
+
+gid_t multiuser_get_ext_gid(userid_t user_id, appid_t app_id) {
+    if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
+        return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_GID_START);
+    } else {
+        return -1;
+    }
+}
+
+gid_t multiuser_get_ext_cache_gid(userid_t user_id, appid_t app_id) {
+    if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
+        return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_CACHE_GID_START);
+    } else {
+        return -1;
+    }
+}
+
+gid_t multiuser_get_shared_gid(userid_t, appid_t app_id) {
+    if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
+        return (app_id - AID_APP_START) + AID_SHARED_GID_START;
+    } else if (app_id >= AID_ROOT && app_id <= AID_APP_START) {
+        return app_id;
+    } else {
+        return -1;
+    }
+}
+
+gid_t multiuser_get_shared_app_gid(uid_t uid) {
+    return multiuser_get_shared_gid(multiuser_get_user_id(uid), multiuser_get_app_id(uid));
+}