Add external IP discovery module

This module performs an HTTP request to ifconfig.me/ip.
The body of the response contains the publicly routable IP from
which the request originated. This can be useful in discovering
routes on pivoted hosts and initial recon as a simple aux module.

modules/auxiliary/scanner/discovery/external_ip.rb

@@ -0,0 +1,59 @@
+##
+# This file is part of the Metasploit Framework and may be subject to
+# redistribution and commercial restrictions. Please see the Metasploit
+# Framework web site for more information on licensing and terms of use.
+# http://metasploit.com/framework/
+##
+
+
+require 'msf/core'
+
+
+class Metasploit3 < Msf::Auxiliary
+
+	# Exploit mixins should be called first
+	include Msf::Exploit::Remote::HttpClient
+	include Msf::Auxiliary::Report
+	include Msf::Auxiliary::Scanner
+
+	def initialize
+		super(
+			'Name'        	=> 'External IP',
+			'Version'     	=> '$Revision: $',
+			'Description'	=> 'This module checks for the public source IP address of the current route to the RHOST',
+			'Author'        => ['RageLtMan'],
+			'License'	=> MSF_LICENSE,
+			'References'	=>
+				[
+					[ 'URL', 'http://ifconfig.me/ip' ],
+				]
+		)
+
+		register_options(
+			[
+				OptEnum.new('RHOSTS', [true, 'The ifconfig.me server to use','49.212.202.172',['49.212.202.172','133.242.129.236']]),
+				OptString.new('VHOST', [true, "The VHOST to use", 'ifconfig.me' ]),
+				OptBool.new('REPORT_HOST', [false, 'Add the found IP to the database', false])
+			], self.class)
+end
+
+	def run_host(ip)
+
+
+		begin
+			agent = datastore['UserAgent']
+			connect
+			res = send_request_raw({'uri' => '/ip', 'method' => 'GET' })
+			our_addr = res.body.strip
+			if Rex::Socket.is_ipv4?(our_addr) or Rex::Socket.is_ipv6?(our_addr)
+				print_good("Source ip to #{ip} is #{our_addr}")
+				report_host(our_addr) if datastore['REPORT_HOST']
+			end
+
+		end
+		rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
+		rescue Timeout::Error, Errno::EINVAL, Errno::ECONNRESET, EOFError, Errno::ECONNABORTED, Errno::ECONNREFUSED, Errno::EHOSTUNREACH =>e
+			puts e.message
+		end
+	end
+