To capture and inspect network traffic for debugging in Go, you can use a library like "gopacket" to easily handle packet capture and analysis. Below are the steps to accomplish this:
Install the "gopacket" library by running the following command:
go get -u github.com/google/gopacket
Import the necessary packages in your Go file:
package main
import (
"fmt"
"log"
"github.com/google/gopacket"
"github.com/google/gopacket/pcap"
)
Get a list of available network interfaces to capture traffic from:
devices, err := pcap.FindAllDevs()
if err != nil {
log.Fatal(err)
}
// Print the available interfaces
for _, device := range devices {
fmt.Println("Interface Name:", device.Name)
}
Select the desired network interface to capture traffic from:
// Select the first available interface
selectedDevice := devices[0]
fmt.Println("Selected Interface:", selectedDevice.Name)
Open the selected network interface for packet capture:
handle, err := pcap.OpenLive(selectedDevice.Name, 1600, true, pcap.BlockForever)
if err != nil {
log.Fatal(err)
}
defer handle.Close()
Create a packet capture packet source from the opened network interface:
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
Start capturing packets and print their details:
for packet := range packetSource.Packets() {
printPacketDetails(packet)
}
Create a function to print the details of each captured packet:
func printPacketDetails(packet gopacket.Packet) {
// Access packet details like source/destination IP, ports, etc.
ipLayer := packet.Layer(layers.LayerTypeIPv4)
if ipLayer != nil {
ip, _ := ipLayer.(*layers.IPv4)
fmt.Printf("Source IP: %s\n", ip.SrcIP)
fmt.Printf("Destination IP: %s\n", ip.DstIP)
}
}
Run the Go file, and it will start capturing network traffic on the selected interface. It will print out the source and destination IP addresses of each captured IPv4 packet.
Note: This example captures network traffic on a single interface. If you want to capture traffic on multiple interfaces simultaneously, you can create multiple packet capture packet sources and handle them accordingly.