/
main.go
59 lines (52 loc) · 1.34 KB
/
main.go
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package main
import (
"fmt"
"log"
"time"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/google/gopacket/pcap"
)
var (
device string = "eth0"
snapshot_len int32 = 1024
promiscuous bool = false
err error
timeout time.Duration = 30 * time.Second
handle *pcap.Handle
// Will reuse these for each packet
ethLayer layers.Ethernet
ipLayer layers.IPv4
tcpLayer layers.TCP
)
func main() {
// Open device
handle, err = pcap.OpenLive(device, snapshot_len, promiscuous, timeout)
if err != nil {
log.Fatal(err)
}
defer handle.Close()
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
for packet := range packetSource.Packets() {
parser := gopacket.NewDecodingLayerParser(
layers.LayerTypeEthernet,
ðLayer,
&ipLayer,
&tcpLayer,
)
foundLayerTypes := []gopacket.LayerType{}
err := parser.DecodeLayers(packet.Data(), &foundLayerTypes)
if err != nil {
fmt.Println("Trouble decoding layers: ", err)
}
for _, layerType := range foundLayerTypes {
if layerType == layers.LayerTypeIPv4 {
fmt.Println("IPv4: ", ipLayer.SrcIP, "->", ipLayer.DstIP)
}
if layerType == layers.LayerTypeTCP {
fmt.Println("TCP Port: ", tcpLayer.SrcPort, "->", tcpLayer.DstPort)
fmt.Println("TCP SYN:", tcpLayer.SYN, " | ACK:", tcpLayer.ACK)
}
}
}
}