Added util

Documentation.md

@@ -1,3 +1,4 @@
+# package main
 ## Variables
 ### Addresses to exchange:
 - var **NewIP** net.IP
@@ -54,3 +55,42 @@ sendDHCPReply creates a response DHCP packet for the VM and sends it
 
 #### func sendDHCPRequest(mt dhcp4.MessageType, reqIP net.IP)
 sendDHCPRequest creates a request DHCP packet for the server and sends it
+
+# package util // import "proxy/util"
+## Functions
+
+#### func DnsQueryDecode(data []byte, start int) (string, int)
+DnsQueryDecode takes encoded hostnames from Microsoft and decodes it
+
+#### func DnsQueryEncode(in string) []byte
+DnsQueryEncode takes string hostnames and encodes it to Microsoft format
+
+#### func GenerateMac(customMAC string) net.HardwareAddr
+GenerateMac generates a random MAC address
+
+#### func GenerateUId(path string) string
+GenerateUId generates a random UId string as hostname
+
+#### func GenerateXID() []byte
+GenerateXID generates a random XID for DHCP
+
+#### func WritePIDFile(filename string)
+WritePIDFile writes the processes PID to a given file
+
+#### func WritePcap(file string, data []byte)
+WritePcap writes the provided data to a given pcap file
+
+## Types
+#### type If bool
+If is a helper type to form expressive ternary expressions being the concatenation of a type conversion and a method call such as:
+`i := If(cond).Int(a, b)`
+For details, see https://stackoverflow.com/a/59375088/1705598
+
+#### func (c If) IP(a, b net.IP) net.IP
+IP returns a if c is true, b otherwise.
+
+#### func (c If) If(a, b interface{}) interface{}
+If returns a if c is true, b otherwise.
+
+#### func (c If) MAC(a, b net.HardwareAddr) net.HardwareAddr
+MAC returns a if c is true, b otherwise.