require 'msf/core'

class Metasploit3 < Msf::Auxiliary

	include Msf::Exploit::Lorcon

	def initialize(info = {})
		super(update_info(info,
			'Name'        => 'Wireless Frame (File) Injector',
			'Description' => %q{
				Inspired by Josh Wright's file2air, this module writes
				wireless frames from a binary file to the air, allowing
				you to substitute some addresses before it gets sent.
				Unlike the original file2air (currently v1.1), this module
				*does* take into account the ToDS and FromDS flags in the
				frame when replacing any specified addresses.
			},
			# 11/03/2008
			'Author'      => 'Kris Katterjohn <katterjohn[at]gmail.com>',
			'License'     => MSF_LICENSE,
			'Version'     => '$Revision$'
		))

		register_options([
				OptString.new('FILE', [true, 'Filename to write to the air']),
				OptString.new('ADDR_DST', [false, 'Target MAC (e.g. 00:DE:AD:BE:EF:00)']),
				OptString.new('ADDR_SRC', [false, 'Source MAC (e.g. 00:DE:AD:BE:EF:00)']),
				OptString.new('BSSID', [false, 'BSSID (e.g. 00:DE:AD:BE:EF:00)']),
				OptInt.new('NUM', [true, 'Number of frames to send', 1])
		], self.class)
	end

	def run
		begin
			frame = File.read(datastore['FILE'])
		rescue ::Exception
			print_status("Couldn't read from \"#{datastore['FILE']}\": #{$!}")
			return
		end

		# Sending too much data can cause local problems, even if it's
		# less than the 802.11 MTU.  Gotta draw the line somewhere.
		if frame.length < 10 or frame.length > 1800
			print_status("Invalid frame size (should be 10-1800 bytes)")
			return
		end

		if datastore['BSSID'] or datastore['ADDR_DST'] or datastore['ADDR_SRC']
			if not substaddrs(frame)
				print_status("This module doesn't support modifying frames with both ToDS and FromDS set")
				return
			end
		end

		open_wifi

		print_status("Writing out #{datastore['NUM']} frames...")

		datastore['NUM'].times do
			wifi.write(frame)
		end

		close_wifi
	end	

	def substaddrs(frame)
		tods = (frame[1] & 1) == 1
		fromds = (frame[1] & 2) == 2

		if tods
			if fromds
				# Not going to handle this 4-address special-case
				return nil
			else
				substaddr1(frame, datastore['BSSID'])
				substaddr2(frame, datastore['ADDR_SRC'])
				substaddr3(frame, datastore['ADDR_DST'])
			end
		else
			if fromds
				substaddr1(frame, datastore['ADDR_DST'])
				substaddr2(frame, datastore['BSSID'])
				substaddr3(frame, datastore['ADDR_SRC'])
			else
				substaddr1(frame, datastore['ADDR_DST'])
				substaddr2(frame, datastore['ADDR_SRC'])
				substaddr3(frame, datastore['BSSID'])
			end
		end

		true
	end

	def substaddr1(frame, addr)
		frame[4,6] = eton(addr) if addr
	end

	def substaddr2(frame, addr)
		frame[10,6] = eton(addr) if addr
	end

	def substaddr3(frame, addr)
		frame[16,6] = eton(addr) if addr
	end
end