1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  * Android BPF library - public API
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *      http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #pragma once
19 
20 #include <libbpf.h>
21 #include <linux/bpf.h>
22 #include <log/log.h>
23 
24 #include <android-base/properties.h>
25 
26 namespace android {
27 namespace bpf {
28 
29 // BPF loader implementation. Loads an eBPF ELF object
30 int loadProg(const char* elfPath, bool* isCritical, const char* prefix = "");
31 
32 // Exposed for testing
33 unsigned int readSectionUint(const char* name, std::ifstream& elfFile, unsigned int defVal);
34 
35 // Wait for bpfloader to load BPF programs.
36 static inline void waitForProgsLoaded() {
37     // infinite loop until success with 5/10/20/40/60/60/60... delay
38     for (int delay = 5;; delay *= 2) {
39         if (delay > 60) delay = 60;
40         if (android::base::WaitForProperty("bpf.progs_loaded", "1", std::chrono::seconds(delay)))
41             return;
42         ALOGW("Waited %ds for bpf.progs_loaded, still waiting...", delay);
43     }
44 }
45 
46 }  // namespace bpf
47 }  // namespace android
48