mirror of
https://github.com/eunomia-bpf/bpf-developer-tutorial.git
synced 2026-02-04 02:34:16 +08:00
104 lines
2.9 KiB
Go
104 lines
2.9 KiB
Go
/*
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* Copyright 2018- The Pixie Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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package main
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import (
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"fmt"
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bpfwrapper2 "github.com/seek-ret/ebpf-training/workshop1/internal/bpfwrapper"
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"github.com/seek-ret/ebpf-training/workshop1/internal/connections"
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"github.com/seek-ret/ebpf-training/workshop1/internal/settings"
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"io/ioutil"
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"log"
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"os"
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"os/signal"
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"os/user"
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"runtime/debug"
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"syscall"
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"time"
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"github.com/iovisor/gobpf/bcc"
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)
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// abortIfNotRoot checks the current user permissions, if the permissions are not elevated, we abort.
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func abortIfNotRoot() {
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current, err := user.Current()
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if err != nil {
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log.Panic(err)
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}
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if current.Uid != "0" {
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log.Panic("sniffer must run under superuser privileges")
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}
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}
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// recoverFromCrashes is a defer function that caches all panics being thrown from the application.
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func recoverFromCrashes() {
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if err := recover(); err != nil {
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log.Printf("Application crashed: %v\nstack: %s\n", err, string(debug.Stack()))
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}
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}
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func main() {
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if len(os.Args) != 2 {
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fmt.Println("Usage: go run main.go <path to bpf source code>")
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os.Exit(1)
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}
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bpfSourceCodeFile := os.Args[1]
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bpfSourceCodeContent, err := ioutil.ReadFile(bpfSourceCodeFile)
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if err != nil {
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log.Panic(err)
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}
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defer recoverFromCrashes()
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abortIfNotRoot()
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if err := settings.InitRealTimeOffset(); err != nil {
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log.Printf("Failed fixing BPF clock, timings will be offseted: %v", err)
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}
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// Catching all termination signals to perform a cleanup when being stopped.
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sig := make(chan os.Signal, 1)
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signal.Notify(sig, syscall.SIGHUP, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM)
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bpfModule := bcc.NewModule(string(bpfSourceCodeContent), nil)
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if bpfModule == nil {
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log.Panic("bpf is nil")
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}
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defer bpfModule.Close()
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connectionFactory := connections.NewFactory(time.Minute)
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go func() {
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for {
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connectionFactory.HandleReadyConnections()
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time.Sleep(10 * time.Second)
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}
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}()
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if err := bpfwrapper2.LaunchPerfBufferConsumers(bpfModule, connectionFactory); err != nil {
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log.Panic(err)
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}
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// Lastly, after everything is ready and configured, attach the kprobes and start capturing traffic.
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if err := bpfwrapper2.AttachKprobes(bpfModule); err != nil {
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log.Panic(err)
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}
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log.Println("Sniffer is ready")
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<-sig
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log.Println("Signaled to terminate")
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}
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