1 /*
2  * Copyright (C) 2023 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 #include <sys/cdefs.h>
20 #include <sys/types.h>
21 
22 __BEGIN_DECLS
23 
24 /*
25  * Perform any required initialization - including opening any required BPF maps. This function
26  * needs to be called before using other functions of this library.
27  *
28  * Returns 0 on success, -EOPNOTSUPP when the function is called on the Android version before
29  * T. Returns a negative POSIX error code (see errno.h) on other failures.
30  */
31 int ADnsHelper_init();
32 
33 /*
34  * The function reads bpf maps and returns whether the given uid has blocked networking or not. The
35  * function is supported starting from Android T.
36  *
37  * |uid| is a Linux/Android UID to be queried. It is a combination of UserID and AppID.
38  * |metered| indicates whether the uid is currently using a billing network.
39  *
40  * Returns 0(false)/1(true) on success, -EUNATCH when the ADnsHelper_init is not called before
41  * calling this function. Returns a negative POSIX error code (see errno.h) on other failures
42  * that return from bpf syscall.
43  */
44 int ADnsHelper_isUidNetworkingBlocked(uid_t uid, bool metered);
45 
46 __END_DECLS
47