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package main
import (
"encoding/hex"
"fmt"
"github.com/chifflier/nfqueue-go/nfqueue"
"os"
"os/signal"
"syscall"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
)
func real_callback(payload *nfqueue.Payload) int {
fmt.Println("Real callback")
fmt.Printf(" id: %d\n", payload.Id)
fmt.Println(hex.Dump(payload.Data))
// Decode a packet
packet := gopacket.NewPacket(payload.Data, layers.LayerTypeIPv4, gopacket.Default)
// Get the TCP layer from this packet
if tcpLayer := packet.Layer(layers.LayerTypeTCP); tcpLayer != nil {
fmt.Println("This is a TCP packet!")
// Get actual TCP data from this layer
tcp, _ := tcpLayer.(*layers.TCP)
fmt.Printf("From src port %d to dst port %d\n", tcp.SrcPort, tcp.DstPort)
}
// Iterate over all layers, printing out each layer type
for _, layer := range packet.Layers() {
fmt.Println("PACKET LAYER:", layer.LayerType())
fmt.Println(gopacket.LayerDump(layer))
}
fmt.Println("-- ")
payload.SetVerdict(nfqueue.NF_ACCEPT)
return 0
}
func main() {
q := new(nfqueue.Queue)
q.SetCallback(real_callback)
q.Init()
q.Unbind(syscall.AF_INET)
q.Bind(syscall.AF_INET)
q.CreateQueue(0)
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
go func(){
for sig := range c {
// sig is a ^C, handle it
_ = sig
q.StopLoop()
}
}()
// XXX Drop privileges here
q.Loop()
q.DestroyQueue()
q.Close()
os.Exit(0)
}
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