yeah i should have done this before, i know

packets/udp.go

@@ -0,0 +1,32 @@
+package packets
+
+import (
+	"github.com/google/gopacket/layers"
+	"net"
+)
+
+func NewUDPProbe(from net.IP, from_hw net.HardwareAddr, to net.IP, port int) (error, []byte) {
+	eth := layers.Ethernet{
+		SrcMAC:       from_hw,
+		DstMAC:       net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+		EthernetType: layers.EthernetTypeIPv4,
+	}
+
+	ip4 := layers.IPv4{
+		Protocol: layers.IPProtocolUDP,
+		Version:  4,
+		TTL:      64,
+		SrcIP:    from,
+		DstIP:    to,
+	}
+
+	udp := layers.UDP{
+		SrcPort: layers.UDPPort(12345),
+		DstPort: layers.UDPPort(port),
+	}
+	udp.Payload = []byte{0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xbe, 0xef}
+
+	udp.SetNetworkLayerForChecksum(&ip4)
+
+	return Serialize(&eth, &ip4, &udp)
+}