capturingWithNFQ.go

//IPTable rules for capturing ssh packets

//sudo iptables -A INPUT -p tcp --dport 22 -j NFQUEUE --queue-num 0
//sudo iptables -A OUTPUT -p tcp --dport 22 -j NFQUEUE --queue-num 0
//sudo iptables -A FORWARD -p tcp --dport 22 -j NFQUEUE --queue-num 0


package main

import (
	"fmt"
	"github.com/AkihiroSuda/go-netfilter-queue"
	"os"
)

func main() {
	var err error

	nfq, err := netfilter.NewNFQueue(0, 100, netfilter.NF_DEFAULT_PACKET_SIZE)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer nfq.Close()
	packets := nfq.GetPackets()

	for true {
		select {
		case p := <-packets:
			fmt.Println(p.Packet.ApplicationLayer())
			fmt.Println(p.Packet.TransportLayer())
			fmt.Println(p.Packet.Dump())
			p.SetVerdict(netfilter.NF_ACCEPT)
		}
	}
}