local bin = require "bin"
local packet = require "packet"
local stdnse = require "stdnse"
local tab = require "tab"
local target = require "target"

--- The following file contains a list of decoders used by the
-- broadcast-listener script. A decoder can be either "ethernet" based or IP
-- based. As we're only monitoring broadcast traffic (ie. traffic not
-- explicitly addressed to us) we're mainly dealing with:
-- o UDP broadcast or multicast traffic
-- o ethernet broadcast traffic
--
-- Hence, the Decoder table defines two sub tables ether and udp.
-- In order to match an incoming UDP packet the destination port number is
-- used, therefore each function is indexed based on their destination port
-- for the udp based decoders. For the ether table each decoder function is
-- indexed according to a pattern that the decoding engine attempts to match.
--
-- Each decoder defines three functions:
-- o <code>new</code> - creates a new instance of the decoder
-- o <code>process</code> - process a packet passed through the 
--							<code>data</code> argument.
-- o <code>getResults</code> - retrieve any discovered results
--
-- The discovery engine creates an instance of each decoder once it's needed.
-- Then discovery engine stores this instance in a decoder table for reference
-- once the next packet of the same type comes in. This allows the engine to
-- discard duplicate packets and to request the collected results at the end
-- of the session.
--
-- Currently, the packet decoder decodes the following protocols:
-- o Ether
--   x ARP requests (IPv4)
--   x CDP - Cisco Discovery Protocol
--   x EIGRP - Cisco Enhanced Interior Gateway Routing Protocol
--   x OSPF - Open Shortest Path First
--
-- o UDP
--   x DHCP
-- 	 x Netbios
--   x SSDP
--   x HSRP
--   x DropBox
--   x Logitech SqueezeBox Discovery
--   x Multicast DNS/Bonjour/ZeroConf
--   x Spotify
--
--
-- @author "Patrik Karlsson <patrik@cqure.net>"
-- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html

-- Version 0.2
-- Created 07/25/2011 - v0.1 - created by Patrik Karlsson
--         02/12/2012 - v0.2 - added support for EIGRP - Tom Sellers
--         07/13/2012 - v0.3 - added support for OSPF - Hani Benhabiles

local bin    = require 'bin'
local target = require 'target'
local tab    = require 'tab'
local packet = require 'packet'

Decoders = {

	ether = {
	
		-- ARP IPv4
		['^00..08000604'] = {
			
			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,
			
			process = function(self, data)
				local ipOps = require("ipOps")
				local pos, hw, proto, hwsize, protosize, opcode = bin.unpack(">SSCCS", data)
				
				-- this shouldn't ever happen, given our filter
				if ( hwsize ~= 6 ) then	return end
				local sender, target = {}, {}
				
				-- if this isn't an ARP request, abort
				if ( opcode ~= 1 ) then return end
				
				pos, sender.mac, 
					sender.ip, 
					target.mac, 
					target.ip = bin.unpack("<H" .. hwsize .. "IH" .. hwsize .. "I", data, pos)
					
				if ( not(self.results) ) then
					self.results = tab.new(3)
					tab.addrow(self.results, 'sender ip', 'sender mac', 'target ip')
				end

				local mac = sender.mac:gsub("(..)(..)(..)(..)(..)(..)","%1:%2:%3:%4:%5:%6")
				stdnse.print_debug(1, "Decoded ARP: %s, %s, %s", ipOps.fromdword(sender.ip), mac, ipOps.fromdword(target.ip))
				if ( not(self.dups[("%u:%s"):format(sender.ip,sender.mac)]) ) then
					if ( target.ALLOW_NEW_TARGETS ) then target.add(sender.ip) end
					self.dups[("%u:%s"):format(sender.ip,sender.mac)] = true
					tab.addrow(self.results, ipOps.fromdword(sender.ip), mac, ipOps.fromdword(target.ip))
				end
				
			end,
			
			getResults = function(self)	return { name = "ARP Request", (self.results and tab.dump(self.results))  } end,
		},
		
		-- CDP
		['^AAAA..00000C2000'] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			getAddresses = function(data)
				local ipOps = require("ipOps")
				local pos, proto_type, proto_len, addr_proto, addr_len, dev_addr, count
				local addr_list = ''
						
				pos, count = bin.unpack(">I", data)
				for i=1, count do
					pos, proto_type, proto_len = bin.unpack(">CC", data, pos)
					pos, addr_proto = bin.unpack(">H" .. proto_len, data, pos)
					if ( addr_proto == 'CC' ) then
						-- IPv4 address, extract it
						pos, addr_len = bin.unpack(">S", data, pos)
						pos, dev_addr = bin.unpack("<I", data, pos)
						addr_list = addr_list .. ' ' .. ipOps.fromdword(dev_addr)
					end
					-- Add code here for IPv6, others
				end
				
				return addr_list
			end,
			
			process = function(self, data)

				local pos, ver, ttl, chk = bin.unpack(">CCS", data, 9)
				if ( ver ~= 2 ) then return end
				if ( not(self.results) ) then
					self.results = tab.new(5)				
					tab.addrow(	self.results, 'ip', 'id', 'platform', 'version', 'notes' )
				end

				local result_part = {}
				result_part.notes = ''
				while ( pos < #data ) do
					local typ, len, typdata
					pos, typ, len = bin.unpack(">SS", data, pos)
					pos, typdata = bin.unpack("A" .. len - 4, data, pos)
					
					-- Device ID
					if ( typ == 1 ) then
						result_part.id = typdata
					-- Version
					elseif ( typ == 5 ) then
						result_part.version = typdata:match(", Version (.-),")
					-- Platform
					elseif ( typ == 6 ) then
						result_part.platform = typdata
					-- Address
					elseif ( typ == 2 ) then
						result_part.ip = self.getAddresses(typdata)
					elseif ( typ == 10) then
						local _, mgmt_vlan = bin.unpack(">S", data,pos - 2)
						result_part.notes = result_part.notes .. 'native vlan:' .. mgmt_vlan .. ' '
					-- Management Address
					elseif ( typ == 22 ) then
						result_part.notes = result_part.notes .. 'mgmt ip:' .. self.getAddresses(typdata) .. ' '
					-- TODO: add more decoding of types here ...
					end
				end
				
				-- TODO: add code for dups check
				if ( not(self.dups[result_part.ip]) ) then
					self.dups[result_part.ip] = true
					tab.addrow( self.results, result_part.ip, result_part.id, result_part.platform, result_part.version, result_part.notes )
				end
			end,
			
			getResults = function(self)	return { name = "CDP", (self.results and tab.dump(self.results) or "")  } end,
		},
		
		
		-- EIGRP Update
		['0201....0000'] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local p = packet.Packet:new( layer3, #layer3 ) 
				-- EIGRP is IP protocol 88 (0x58), so verify this
				if ( p.ip_p ~= 88 ) then return end

				local data = layer3:sub(p.ip_data_offset + 1)
				local eigrp = require("eigrp")
				local route_type, proto_name
				-- Extract the EIGRP header
				local response = eigrp.EIGRP.parse(data)

				if response then
					-- Iterate over tlv tables
					for _, tlv in pairs(response.tlvs) do
						if eigrp.EIGRP.isRoutingTLV(tlv.type) then
							if ( not(self.results) ) then
								self.results = tab.new(7)
								tab.addrow(self.results, 'Sender IP', 'AS#', 'Route Type', 'Destination', 'Next hop', 'Ext Protocol', 'Orig Router ID')
							end
							if tlv.type == 0x102 then
								route_type = "Internal"
							elseif tlv.type == 0x103 then
								route_type = "External"
								for name, value in pairs(eigrp.EXT_PROTO) do
									if value == tlv.eproto then
										proto_name = name
										break
									end 
								end
							end 
							if ( not(self.dups[("%s:%s:s:%s"):format(p.ip_src, response.as, tlv.type, tlv.dst)]) ) then
								if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
									self.dups[("%s:%s:%s:%s"):format(p.ip_src, response.as, tlv.type, tlv.dst)] = true
									tab.addrow( self.results, p.ip_src, response.as, route_type, tlv.dst, tlv.nexth, proto_name or 'X', tlv.orouterid or 'X')
								end
							end
						end
					end
				end,
				
				getResults = function(self)	return { name = "EIGRP Update", (self.results and tab.dump(self.results) or "")  } end,
			},

			['0205....0000'] = {

				new = function(self)
					local o = { dups = {} }
					setmetatable(o, self)
					self.__index = self
					return o
				end,

				process = function(self, layer3)

					local p = packet.Packet:new( layer3, #layer3 ) 
					-- EIGRP is IP protocol 88 (0x58), so verify this
					if ( p.ip_p ~= 88 ) then return end

					local data = layer3:sub(p.ip_data_offset + 1)			
					local eigrp = require("eigrp")
					-- Extract the EIGRP header
					local response = eigrp.EIGRP.parse(data)
					-- See if Software version TLV is included
					local swvertlv
					for num, tlv in pairs(response.tlvs) do
						if tlv.type == eigrp.TLV.SWVER then
							swvertlv = num
						end
					end

					if swvertlv then
						if ( not(self.results) ) then
							self.results = tab.new(5)
							tab.addrow(self.results, 'Sender IP', 'AS number', 'EIGRP version', 'IOS version')
						end

					if ( not(self.dups[("%s:%s"):format(p.ip_src,response.as)]) ) then
						if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
							self.dups[("%s:%s"):format(p.ip_src,response.as)] = true
							tab.addrow( self.results, p.ip_src, response.as, response.tlvs[swvertlv].majv .. '.' .. response.tlvs[swvertlv].minv, response.tlvs[swvertlv].majtlv .. '.' .. response.tlvs[swvertlv].mintlv)
						end
					end	
				end,

				getResults = function(self)	return { name = "EIGRP Hello", (self.results and tab.dump(self.results) or "")  } end,
			},

			-- OSPF
			['02010'] = { -- OSPFv2 Hello packet

				new = function(self)
					local o = { dups = {} }
					setmetatable(o, self)
					self.__index = self
					return o
				end,

				process = function(self, layer3)
					local p = packet.Packet:new( layer3, #layer3 ) 
					-- IP Protocol is 89 for OSPF
					if p.ip_p ~= 89 then return end

					local ospf = require("ospf")
					local data = layer3:sub(p.ip_data_offset + 1)			
					local header = ospf.OSPF.Header.parse(data)
					if header then
						if not(self.results) then
							self.results = tab.new(5)
							tab.addrow(self.results, 'Source IP', 'Router ID', 'Area ID', 'Auth Type', 'Password')
						end
						local srcip = p.ip_src
						local areaid = header.area_id
						local routerid = header.router_id
						local authtype = header.auth_type
						local authdata 

						-- Format authentication type and data
						if header.auth_type == 0 then
							authtype = "None"
							authdata = ''
						elseif header.auth_type == 1 then
							authtype = "Password"
							authdata = header.auth_data.password
						elseif header.auth_type == 2 then
							authtype = "OSPF MD5"
							authdata = "" -- Not really helpful, as the MD5 
							-- is applied to the whole packet+password
						else
			 				-- Error
							stdnse.print_debug("Unknown OSPF auth type %d", header.auth_type)
							return
						end

						if ( not(self.dups[("%s:%s"):format(routerid,areaid)]) ) then
							if ( target.ALLOW_NEW_TARGETS ) then target.add(routerid) end
							self.dups[("%s:%s"):format(routerid,areaid)] = true
							tab.addrow( self.results, srcip, routerid, areaid, authtype, authdata)
						end
					else
						return nil
					end
				end,

				getResults = function(self)	return { name = "OSPF Hello", (self.results and tab.dump(self.results)) } end,
			},
		},
		
		udp = {

			-- DHCP
			[68] = {
			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			getOption = function(options, name)
				for _, v in ipairs(options) do
					if ( v.name == name ) then
						if ( type(v.value) == "table" ) then
							return stdnse.strjoin(", ", v.value)
						else
							return v.value
						end
					end
				end
			end,

			process = function(self, layer3)
				local dhcp = require("dhcp")
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)

				-- the dhcp.parse function isn't optimal for doing
				-- this, but it will do for now. First, we need to
				-- extract the xid as the parse function checks that it
				-- was the same as in the request, which we didn't do.
				local pos, msgtype, _, _, _, xid = bin.unpack("<CCCCA4", data)

				-- attempt to parse the data
				local status, result = dhcp.dhcp_parse(data, xid)

				if ( status ) then
					if ( not(self.results) ) then
				    self.results = tab.new(6)
				    tab.addrow(self.results, "srv ip", "cli ip", "mask", "gw", "dns", "vendor" )
					end
				local uniq_key = ("%s:%s"):format(p.ip_src, result.yiaddr_str)

				if ( not(self.dups[uniq_key]) ) then
					if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
						local mask = self.getOption(result.options, "Subnet Mask") or "-"
						local gw = self.getOption(result.options, "Router") or "-"
						local dns = self.getOption(result.options, "Domain Name Server") or "-"
						local vendor = self.getOption(result.options, "Class Identifier") or "-"
						stdnse.print_debug(1, "Decoded DHCP: %s, %s, %s, %s, %s, %s", p.ip_src, result.yiaddr_str, mask, gw, dns, vendor)
						tab.addrow(self.results, p.ip_src, result.yiaddr_str, mask, gw, dns, vendor )
					end
				end
			end,

			getResults = function(self)	return { name = "DHCP", (self.results and tab.dump(self.results) or "") } end,
		},

		-- Netbios
		[137] = {

			new = function(self)
				local o = { 
					reg_dups = {},
					query_dups = {},
					reg_result = tab.new(2),
					query_result = tab.new(2)
				}
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local dns = require('dns')
				local bin = require('bin')
				local netbios = require('netbios')
				local tab = require('tab')
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)

				local dresp = dns.decode(data)
				if ( not(dresp.questions) or #dresp.questions < 1 ) then return end

				local name = netbios.name_decode("\32" .. dresp.questions[1].dname)

				local function add_record(isreg, ip, name)
					local res = (isreg and self.reg_result or self.query_result)
					local dup = (isreg and self.reg_dups or self.query_dups)

					if ( #res == 0 ) then
						tab.addrow(res, 'ip', 'query')
					end
					stdnse.print_debug(1, 'Decoded Netbios(%s): %s, %s', (isreg and "Registration" or "Query"), ip, name)

					if ( not(dup[ip]) or not(dup[ip][name]) ) then
						if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
						tab.addrow(res, ip, name)
						dup[ip] = dup[ip] or {}
						dup[ip][name] = true
					end
				end
				add_record( ( dresp.flags.OC2 and dresp.flags.OC4 ), p.ip_src, name )
			end,

			getResults = function(self)
				local result = { name = "Netbios" }
				if ( #self.reg_result > 1) then
					table.insert(result, { name = "Registrations", tab.dump(self.reg_result) })
				end
				if ( #self.query_result > 1 ) then
					table.insert(result, { name = "Query", tab.dump(self.query_result) })
				end
				return result
			end,
		},

		-- BROWSER
		[138] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local bin = require('bin')
				local netbios = require('netbios')
				local tab = require('tab')
				local ipOps = require("ipOps")
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				
				local pos, ip, _, src, dst = 5
				pos, ip, _, _, _, src, dst = bin.unpack("<ISSSA34A34", data, pos)
				
				ip = ipOps.fromdword(ip)
				src = netbios.name_decode(src)
				dst = netbios.name_decode(dst)
				stdnse.print_debug(1, "Decoded BROWSER: %s, %s, %s", ip, src, dst)
				
				local dup_rec = ("%s:%s:%s"):format(ip, src, dst)
				if ( not(self.dups[dup_rec]) ) then
					self.dups[dup_rec] = true
					if ( not(self.results) ) then
						self.results = tab.new(3)
						tab.addrow(self.results, 'ip', 'src', 'dst')
					end
					tab.addrow(self.results, ip, src, dst)
				end
			end,
			
			getResults = function(self)	return { name = "Browser", (self.results and tab.dump(self.results)) } end,
		},
		
		-- DHCPv6
		[547] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local tab = require('tab')
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				
				local dhcpv6 = require("dhcp6")
				local resp = dhcpv6.DHCP6.Response.parse(data)

				for _, v in ipairs(resp.opts or {}) do
					if v.resp and v.resp.fqdn then
						if ( not(self.results) ) then
							self.results = tab.new(2)
							tab.addrow(self.results, 'ip', 'fqdn')
						end
						if ( not(self.dups[p.ip_src]) or not(self.dups[p.ip_src][v.resp.fqdn]) ) then
							tab.addrow(self.results, p.ip_src, v.resp.fqdn )
							self.dups[p.ip_src] = self.dups[p.ip_src] or {}
							self.dups[p.ip_src][v.resp.fqdn] = true
						end
					end
				end
			end,
			
			getResults = function(self)	return { name = "DHCP6", (self.results and tab.dump(self.results)) } end,
		},

		-- CUPS
		[631] = {
			
			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local tab = require('tab')
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				
				local function split(str)
					local start, pos, stop = 1, 1
					local pattern = ""
					local result = {}

					while(pos) do
						start = pos + #pattern
						pos, stop = str:find("\"", start)
						pattern = (pos == start and "\" " or " ")
						pos, stop = str:find(pattern, start + 1)
						table.insert(result, str:sub(start, (stop and stop - (#pattern))))
					end
					return ( #result > 0 and result or nil )
				end
				
				local results = split(data)
				local uri = ( #results > 3 and results[3]:match('[^%"]+') )
				local loc = ( #results > 4 and results[4]:match('[^%"]+') or "")
				local info = ( #results > 5 and results[5]:match('[^%"]+') or "")
				local model = ( #results > 6 and results[6]:match('[^%"]+') or "")
				
				if ( not(self.results) ) then
					self.results = tab.new(4)
					tab.addrow(self.results, 'ip', 'uri', 'loc', 'model')
				end
				
				stdnse.print_debug(1, "Decoded CUPS: %s, %s, %s, %s", p.ip_src, uri, loc, model)
				if ( not(self.dups[p.ip_src]) or not(self.dups[p.ip_src][uri]) ) then
					tab.addrow(self.results, p.ip_src, uri, loc, model)
					self.dups[p.ip_src] = self.dups[p.ip_src] or {}
					self.dups[p.ip_src][uri] = self.dups[p.ip_src][uri] or true
				end
			end,
			
			getResults = function(self)	return { name = "CUPS", (self.results and tab.dump(self.results)) } end,
			
		},

		-- SSDP
		[1900] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)

				local headers = stdnse.strsplit("\r\n", data)
				for _, h in ipairs(headers) do
					local st = ""
					if ( h:match("^ST:.*") ) then
						st = h:match("^ST:(.*)")
						if ( not(self.results) ) then
							self.results = tab.new(1)
							tab.addrow(	self.results, 'ip', 'uri' )
						end
						if ( not(self.dups[("%s:%s"):format(p.ip_src,st)]) ) then
							if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
							tab.addrow(	self.results, p.ip_src, st )
							self.dups[("%s:%s"):format(p.ip_src,st)] = true
						end
					end
				end
			end,

			getResults = function(self)	return { name = "SSDP", (self.results and tab.dump(self.results)) } end,
		},

		--- HSRP
		[1985] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				local ipOps = require("ipOps")

				local State = {
					[0] = "Initial",
					[1] = "Learn",
					[2] = "Listen",
					[4] = "Speak",
					[8] = "Standby",
					[16] = "Active"
				}

				local Op = {
					[0] = "Hello",
					[1] = "Coup",
					[2] = "Resign",
				}

				local pos, version, op, state, _, _, prio, group, _, secret = bin.unpack("CCCCCCCCz", data) 
				if ( version ~= 0 ) then return end
				pos = pos + ( 7 - #secret )
				local virtip
				pos, virtip = bin.unpack("<I", data, pos)

				if ( not(self.dups[p.ip_src]) ) then
					if ( not(self.results) ) then
						self.results = tab.new(7)
						tab.addrow(self.results, 'ip', 'version', 'op', 'state', 'prio', 'group', 'secret', 'virtual ip')
					end
					if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
					self.dups[p.ip_src] = true
					tab.addrow(self.results, p.ip_src, version, Op[op], State[state], prio, group, secret, ipOps.fromdword(virtip))
				end
			end,

			getResults = function(self)	return { name = "HSRP", (self.results and tab.dump(self.results) or "") } end,

		},


		-- Dropbox
		[17500] = {
			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local json = require("json")
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				local status, info = json.parse(data)
				if ( not(status) ) then
					return false, "Failed to parse JSON data"
				end

				-- Add host to list.
				for _, key1 in pairs({"namespaces", "version"}) do
					for key2, val in pairs(info[key1]) do
						info[key1][key2] = tostring(info[key1][key2])
					end
				end

				if ( not(self.results) ) then
					self.results = tab.new(6)
					tab.addrow(
						self.results,
						'displayname',
						'ip',
						'port',
						'version',
						'host_int',
						'namespaces'
					)
				end

				if ( not(self.dups[p.ip_src]) ) then
					tab.addrow(
						self.results,
						info.displayname,
						p.ip_src,
						info.port,
						stdnse.strjoin(".", info.version),
						info.host_int,
						stdnse.strjoin(", ", info.namespaces)
					)
					self.dups[p.ip_src] = true
					if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
				end
			end,

			getResults = function(self)	return { name = "DropBox", (self.results and tab.dump(self.results) or "") } end,
		},

		--- Squeezebox Discovery
		[3483] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
			local p = packet.Packet:new( layer3, #layer3 )
			local data = layer3:sub(p.udp_offset + 9)

			if ( data:match("^eIPAD") ) then
				if ( not(self.results) ) then
					self.results = tab.new(1)
					tab.addrow(	self.results, 'ip' )
				end

				if ( not(self.dups[p.ip_src]) ) then
					tab.addrow(	self.results, p.ip_src )
					self.dups[p.ip_src] = true
					if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
				end
			end

			end,

			getResults = function(self)	return { name = "Squeezebox Discovery", (self.results and tab.dump(self.results) or "") } end,

		},

		-- Multicast DNS/BonJour/ZeroConf
		[5353] = {

			new = function(self)
				local o = { 
					dups = {},
					macbooks = {},
					generic = {}
				}
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local dns = require('dns')
				local bin = require('bin')
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
				local dresp = dns.decode(data)
				local name

				if ( dresp.questions and #dresp.questions > 0 ) then
					name = dresp.questions[1].dname
				elseif ( dresp.answers and #dresp.answers > 0 ) then
					-- Identify MacBooks
					local macbook, model, ip, ipv6
					
					if ( p.ip_src:match(":") ) then
						ipv6 = p.ip_src
					else
						ip = p.ip_src
					end
					
					for i in ipairs(dresp.answers) do
						if ( dresp.answers[i]['data'] ) then
							local _, data = bin.unpack("p", dresp.answers[i]['data'])
							if ( data ) then
								model = data:match("^model=(.*)")
								if ( model ) then
									macbook = dresp.answers[i]['dname']:match("^(.-)%._")
								end
							end
						elseif ( dresp.answers[i]['ip'] ) then
							ip = dresp.answers[i]['ip']
						elseif ( dresp.answers[i]['ipv6'] ) then
							ipv6 = dresp.answers[i]['ipv6']
						elseif ( not(macbook) and dresp.answers[i]['domain'] ) then
							macbook = dresp.answers[i]['domain']
						end
					end
					if ( macbook and model ) then
						self.macbooks[macbook] = self.macbooks[macbook] or {}
						self.macbooks[macbook]['macbook'] = self.macbooks[macbook]['macbook'] or macbook
						self.macbooks[macbook]['model'] = self.macbooks[macbook]['model'] or model
						self.macbooks[macbook]['ip'] = self.macbooks[macbook]['ip'] or ip
						self.macbooks[macbook]['ipv6'] = self.macbooks[macbook]['ipv6'] or ipv6
						stdnse.print_debug(1, "Decoded MDNS(MacBook): %s, %s, %s, %s", 
							(self.macbooks[macbook]['ip'] or ""), (self.macbooks[macbook]['ipv6'] or ""),
							self.macbooks[macbook]['model'], self.macbooks[macbook]['macbook'])
					else
						name = dresp.answers[1].dname
						if ( not(name) ) then return end
						self.generic[name] = self.generic[name] or {}
						self.generic[name]['name'] = self.generic[name]['name'] or name
						if ( p.ip_src:match(":") ) then
							self.generic[name]['ipv6'] = p.ip_src
						else
							self.generic[name]['ip'] = p.ip_src
						end
						stdnse.print_debug(1, "Decoded MDNS(Generic): %s, %s", name, p.ip_src)
					end
				end
			end,

			getResults = function(self)
				local tab = require('tab')
				local result = { name = "MDNS" }
				
				-- build a macbooks table
				local macbooks, generic

				if ( next(self.generic) ) then
					table.sort(self.generic)
					generic = tab.new(3)
					tab.addrow(generic, 'ip', 'ipv6', 'name')
					
					for name, v in pairs(self.generic) do
						tab.addrow(generic, (v.ip or ""), (v.ipv6 or ""), name)
					end
					table.insert(result, { name = 'Generic', tab.dump(generic) } )
				end

				if ( next(self.macbooks) ) then
					table.sort(self.macbooks)
					macbooks = tab.new(4)
					tab.addrow(macbooks, 'ip', 'ipv6', 'name', 'model')
					
					for _, v in pairs(self.macbooks) do
						tab.addrow(macbooks, (v.ip or ""), (v.ipv6 or ""), v.macbook, v.model)
					end
					table.insert(result, { name = 'Macbooks', tab.dump(macbooks) } )
				end
				
				return result
			end,
		},
		
		[5355] = { -- LLMNR
			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local tab = require('tab')
				local dns = require('dns')
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)
			
				local resp = dns.decode(data)
				if ( not(self.results) )  then
					self.results = tab.new(2)
					tab.addrow(self.results, 'ip', 'query')
				end
				
				local name = (( resp.questions and #resp.questions > 0 ) and resp.questions[1].dname )
				if ( not(name) ) then return end
				stdnse.print_debug(1, "Decoded LLMNR: %s, %s", p.ip_src, name)
				
				if ( not(self.dups[("%s:%s"):format(p.ip_src, name)]) ) then
					self.dups[("%s:%s"):format(p.ip_src, name)] = true
					tab.addrow(self.results, p.ip_src, name)
				end
			end,
			
			getResults = function(self)	return { name = "LLMNR", (self.results and tab.dump(self.results)) } end,
		},

		--- Spotify
		[57621] = {

			new = function(self)
				local o = { dups = {} }
				setmetatable(o, self)
				self.__index = self
				return o
			end,

			process = function(self, layer3)
				local p = packet.Packet:new( layer3, #layer3 )
				local data = layer3:sub(p.udp_offset + 9)

				if ( data:match("^SpotUdp") ) then
					if ( not(self.results) ) then
						self.results = tab.new(1)
						tab.addrow(	self.results, 'ip' )
					end

					if ( not(self.dups[p.ip_src]) ) then
						tab.addrow(	self.results, p.ip_src )
						self.dups[p.ip_src] = true
						if ( target.ALLOW_NEW_TARGETS ) then target.add(p.ip_src) end
					end
				end

			end,

			getResults = function(self)	return { name = "Spotify", (self.results and tab.dump(self.results)) } end,

		}

	}
}
