yeah i should have done this before, i know

packets/arp.go

@@ -0,0 +1,40 @@
+package packets
+
+import (
+	"github.com/google/gopacket/layers"
+	"net"
+)
+
+func NewARPTo(from net.IP, from_hw net.HardwareAddr, to net.IP, to_hw net.HardwareAddr, req uint16) (layers.Ethernet, layers.ARP) {
+	eth := layers.Ethernet{
+		SrcMAC:       from_hw,
+		DstMAC:       net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+		EthernetType: layers.EthernetTypeARP,
+	}
+	arp := layers.ARP{
+		AddrType:          layers.LinkTypeEthernet,
+		Protocol:          layers.EthernetTypeIPv4,
+		HwAddressSize:     6,
+		ProtAddressSize:   4,
+		Operation:         req,
+		SourceHwAddress:   from_hw,
+		SourceProtAddress: from.To4(),
+		DstHwAddress:      to_hw,
+		DstProtAddress:    to.To4(),
+	}
+
+	return eth, arp
+}
+func NewARP(from net.IP, from_hw net.HardwareAddr, to net.IP, req uint16) (layers.Ethernet, layers.ARP) {
+	return NewARPTo(from, from_hw, to, []byte{0, 0, 0, 0, 0, 0}, req)
+}
+
+func NewARPRequest(from net.IP, from_hw net.HardwareAddr, to net.IP) (error, []byte) {
+	eth, arp := NewARP(from, from_hw, to, layers.ARPRequest)
+	return Serialize(&eth, &arp)
+}
+
+func NewARPReply(from net.IP, from_hw net.HardwareAddr, to net.IP, to_hw net.HardwareAddr) (error, []byte) {
+	eth, arp := NewARPTo(from, from_hw, to, to_hw, layers.ARPReply)
+	return Serialize(&eth, &arp)
+}