558 lines
16 KiB
Ruby
558 lines
16 KiB
Ruby
# -*- coding: binary -*-
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module Msf
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###
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#
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# This module provides methods for sending and receiving
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# raw packets. It should be preferred over the soon-to-be
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# deprecated Rex::Socket::Ip and Msf::Exploite::Remote::Ip
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# mixins.
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#
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# Please see the pcaprub documentation for more information
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# on how to use capture objects.
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#
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###
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module Exploit::Capture
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#
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# Initializes an instance of an exploit module that captures traffic
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#
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def initialize(info = {})
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super
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register_options(
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[
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OptPath.new('PCAPFILE', [false, 'The name of the PCAP capture file to process']),
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OptString.new('INTERFACE', [false, 'The name of the interface']),
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OptString.new('FILTER', [false, 'The filter string for capturing traffic']),
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OptInt.new('SNAPLEN', [true, 'The number of bytes to capture', 65535]),
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OptInt.new('TIMEOUT', [true, 'The number of seconds to wait for new data', 500]),
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Opt::RHOST
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], Msf::Exploit::Capture
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)
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register_advanced_options(
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[
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OptInt.new('UDP_SECRET', [true, 'The 32-bit cookie for UDP probe requests.', 1297303091]),
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OptAddress.new('GATEWAY', [false, 'The gateway IP address. This will be used rather than a random remote address for the UDP probe, if set.']),
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OptInt.new('NETMASK', [false, 'The local network mask. This is used to decide if an address is in the local network.', 24]),
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], Msf::Exploit::Capture
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)
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require 'packetfu'
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begin
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require 'pcaprub'
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@pcaprub_loaded = true
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rescue ::Exception => e
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@pcaprub_loaded = false
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@pcaprub_error = e
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end
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end
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def stats_recv(pcap=self.capture)
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return(0) if not pcap
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pcap.stats['recv']
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end
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def stats_drop(pcap=self.capture)
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return(0) if not pcap
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pcap.stats['drop']
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end
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def stats_ifdrop(pcap=self.capture)
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return(0) if not pcap
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pcap.stats['ifdrop']
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end
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#
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# Opens a handle to the specified device
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#
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def open_pcap(opts={})
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check_pcaprub_loaded
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if RUBY_PLATFORM == "i386-mingw32"
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if opts['INTERFACE'] or datastore['INTERFACE']
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dev = opts['INTERFACE'] || datastore['INTERFACE']
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if is_interface?(dev)
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dev = get_interface_guid(dev)
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end
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end
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else
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dev = opts['INTERFACE'] || datastore['INTERFACE'] || nil
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end
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len = (opts['SNAPLEN'] || datastore['SNAPLEN'] || 65535).to_i
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tim = (opts['TIMEOUT'] || datastore['TIMEOUT'] || 0).to_i
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fil = opts['FILTER'] || datastore['FILTER']
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arp = opts['ARPCAP'] || true
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# Look for a PCAP file
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cap = datastore['PCAPFILE'] || ''
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if(not cap.empty?)
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if(not File.exists?(cap))
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raise RuntimeError, "The PCAP file #{cap} could not be found"
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end
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self.capture = ::Pcap.open_offline(cap)
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else
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dev ||= ::Pcap.lookupdev
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unless RUBY_PLATFORM == "i386-mingw32"
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system("ifconfig", dev, "up")
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end
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self.capture = ::Pcap.open_live(dev, len, true, tim)
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if arp
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self.arp_capture = ::Pcap.open_live(dev, 512, true, tim)
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preamble = datastore['UDP_SECRET'].to_i
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arp_filter = "arp[6:2] = 2 or (udp[8:4] = #{preamble})"
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self.arp_capture.setfilter(arp_filter)
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end
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end
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if (not self.capture)
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raise RuntimeError, "Could not start the capture process"
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elsif (arp and !self.arp_capture and cap.empty?)
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raise RuntimeError, "Could not start the ARP capture process"
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end
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self.capture.setfilter(fil) if fil
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end
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def close_pcap
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return if not self.capture
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self.capture = nil
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self.arp_capture = nil
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GC.start()
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end
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def capture_extract_ies(raw)
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set = {}
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ret = 0
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idx = 0
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len = 0
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while (idx < raw.length)
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len = raw[idx+1]
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return set if not len
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set[ raw[idx] ] ||= []
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set[ raw[idx] ].push(raw[idx + 2, len])
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idx += len + 2
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end
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return set
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end
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#
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# This monstrosity works around a series of bugs in the interrupt
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# signal handling of Ruby 1.9
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#
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def each_packet
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return if not capture
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begin
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@capture_count = 0
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reader = framework.threads.spawn("PcapReceiver", false) do
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capture.each do |pkt|
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yield(pkt)
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@capture_count += 1
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end
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end
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reader.join
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rescue ::Exception
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raise $!
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ensure
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reader.kill if reader.alive?
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end
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@capture_count
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end
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# Injects a packet on the wire. For all injection-related functions, it's
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# on the module to open up a capture device first (this way, we don't
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# needlessly spawn new capture devices).
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def inject(pkt="",pcap=self.capture)
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check_pcaprub_loaded
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if not pcap
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raise RuntimeError, "Could not access the capture process (remember to open_pcap first!)"
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else
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pcap.inject(pkt.to_s) # Can be a PacketFu Packet object or a pre-packed string
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end
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end
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# Injects an Ethernet packet with an optional payload. The payload
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# may be a regular PacketFu packet, an EthHeader, or a string.
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def inject_eth(args={})
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eth_daddr = args[:eth_daddr] || "ff:ff:ff:ff:ff:ff"
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eth_saddr = args[:eth_saddr] || "00:00:00:00:00:00"
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eth_type = args[:eth_type] || 0x0800 # IP default
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payload = args[:payload]
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pcap = args[:pcap] || self.capture
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p = PacketFu::EthPacket.new
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p.eth_daddr = eth_daddr
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p.eth_saddr = eth_saddr
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p.eth_proto = eth_type
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if payload
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if payload.kind_of? PacketFu::EthPacket
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p.payload = payload.eth_header.body
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elsif payload.kind_of? PacketFu::EthHeader
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p.payload = payload.body
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else
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p.payload = payload.to_s
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end
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end
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inject p.to_s,pcap
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end
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def inject_pcap(pcap_file, filter=nil, delay = 0, pcap=self.capture)
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check_pcaprub_loaded
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if not pcap
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raise RuntimeError, "Could not access the capture process (remember to open_pcap first!)"
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end
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if(not File.exists?(pcap_file))
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raise RuntimeError, "The PCAP file #{pcap_file} could not be found"
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end
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if(pcap_file.empty?)
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raise RuntimeError, "The PCAP file #{pcap_file} is empty"
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end
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capture_file = ::Pcap.open_offline(pcap_file)
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capture_file.setfilter(filter) if filter
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while (pkt = capture_file.next) do
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pcap.inject(pkt)
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Kernel.select(nil, nil, nil, (delay * 1.0)/1000)
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end
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GC.start
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end
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# Capture_sendto is intended to replace the old Rex::Socket::Ip.sendto method. It requires
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# a payload and a destination address. To send to the broadcast address, set bcast
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# to true (this will guarantee that packets will be sent even if ARP doesn't work
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# out).
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def capture_sendto(payload="", dhost=nil, bcast=false, dev=nil)
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raise RuntimeError, "Could not access the capture process (remember to open_pcap first!)" unless self.capture
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raise RuntimeError, "Must specify a host to sendto" unless dhost
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dev ||= datastore['INTERFACE']
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dst_mac,src_mac = lookup_eth(dhost,dev)
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if dst_mac == nil and not bcast
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return false
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end
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inject_eth(:payload => payload, :eth_daddr => dst_mac, :eth_saddr => src_mac)
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end
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# The return value either be a PacketFu::Packet object, or nil
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def inject_reply(proto=:udp,pcap=self.capture)
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reply = nil
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to = (datastore['TIMEOUT'] || 500).to_f / 1000.0
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if not pcap
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raise RuntimeError, "Could not access the capture process (remember to open_pcap first!)"
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else
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begin
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::Timeout.timeout(to) do
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pcap.each do |r|
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packet = PacketFu::Packet.parse(r)
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next unless packet.proto.map {|x| x.downcase.to_sym}.include? proto
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reply = packet
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break
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end
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end
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rescue ::Timeout::Error
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end
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end
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return reply
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end
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# This ascertains the correct Ethernet addresses one should use to
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# ensure injected IP packets actually get where they are going, and
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# manages the self.arp_cache hash. It always uses self.arp_capture
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# do inject and capture packets, and will always first fire off a
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# UDP packet using the regular socket to learn the source host's
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# and gateway's mac addresses.
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def lookup_eth(addr=nil,iface=nil)
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raise RuntimeError, "Could not access the capture process." if not self.arp_capture
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self.arp_cache ||= {}
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self.dst_cache ||= {}
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return self.dst_cache[addr] if self.dst_cache[addr]
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if !self.arp_cache[Rex::Socket.source_address(addr)]
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probe_gateway(addr)
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end
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src_mac = self.arp_cache[Rex::Socket.source_address(addr)]
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if should_arp?(addr)
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dst_mac = self.arp_cache[addr] || arp(addr)
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else
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dst_mac = self.arp_cache[:gateway]
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end
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self.dst_cache[addr] = [dst_mac,src_mac]
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end
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def probe_gateway(addr)
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dst_host = (datastore['GATEWAY'] || IPAddr.new((rand(16777216) + 2969567232), Socket::AF_INET).to_s)
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dst_port = rand(30000)+1024
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preamble = [datastore['UDP_SECRET']].pack("N")
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secret = "#{preamble}#{Rex::Text.rand_text(rand(0xff)+1)}"
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UDPSocket.open.send(secret,0,dst_host,dst_port)
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begin
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to = (datastore['TIMEOUT'] || 1500).to_f / 1000.0
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::Timeout.timeout(to) do
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while(my_packet = inject_reply(:udp,self.arp_capture))
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if my_packet.payload == secret
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dst_mac = self.arp_cache[:gateway] = my_packet.eth_daddr
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src_mac = self.arp_cache[Rex::Socket.source_address(addr)] = my_packet.eth_saddr
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return [dst_mac,src_mac]
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else
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next
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end
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end
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end
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rescue ::Timeout::Error
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# Well, that didn't work (this common on networks where there's no gatway, like
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# VMWare network interfaces. We'll need to use a fake source hardware address.
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self.arp_cache[Rex::Socket.source_address(addr)] = "00:00:00:00:00:00"
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end
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end
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# A pure-Ruby ARP exchange. It uses self.arp_capture to send and recv
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# packets, rather than self.capture.
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def arp(target_ip=nil)
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return self.arp_cache[target_ip] if self.arp_cache[target_ip]
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return self.arp_cache[:gateway] unless should_arp? target_ip
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source_ip = Rex::Socket.source_address(target_ip)
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raise RuntimeError, "Could not access the capture process." if not self.arp_capture
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p = arp_packet(target_ip,source_ip)
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inject_eth(:eth_type => 0x0806,
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:payload => p,
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:pcap => self.arp_capture,
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:eth_saddr => self.arp_cache[Rex::Socket.source_address(target_ip)]
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)
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begin
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to = (datastore['TIMEOUT'] || 500).to_f / 1000.0
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::Timeout.timeout(to) do
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while(my_packet = inject_reply(:arp,self.arp_capture))
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if my_packet.arp_saddr_ip == target_ip
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self.arp_cache[target_ip] = my_packet.eth_saddr
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return self.arp_cache[target_ip]
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else
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next
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end
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end
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end
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rescue ::Timeout::Error
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end
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end
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# Creates a full ARP packet, mainly for use with inject_eth()
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def arp_packet(target_ip=nil,source_ip=nil)
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p = PacketFu::ARPPacket.new
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p.arp_opcode = 1
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p.arp_daddr_ip = target_ip || datastore['RHOST']
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p.arp_saddr_ip = source_ip || datastore['LHOST']
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my_eth = self.arp_cache[Rex::Socket.source_address(target_ip)]
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p.arp_saddr_mac = my_eth || "00:00:00:00:00:00"
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return p
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end
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# Allow modules to reset their arp caches arbitrarily.
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def expire_arpcache
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self.arp_cache = {}
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end
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# For compatabilty with Msf::Exploit::Remote::Ip
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def rhost
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datastore['RHOST']
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end
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def check_pcaprub_loaded
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if not @pcaprub_loaded
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print_status("The Pcaprub module is not available: #{@pcaprub_error}")
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raise RuntimeError, "Pcaprub not available"
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else
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true
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end
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end
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def lookupnet
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check_pcaprub_loaded
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dev = datastore['INTERFACE'] || ::Pcap.lookupdev
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mask = datastore['NETMASK'] || 24
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begin
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my_net = IPAddr.new("#{Pcap.lookupnet(dev).first}/#{mask}")
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rescue RuntimeError => e
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@pcaprub_error = e
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print_status("Cannot stat device: #{@pcaprub_error}")
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raise RuntimeError, "Pcaprub error: #{@pcaprub_error}"
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end
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return my_net
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end
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def should_arp?(ip)
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@mydev ||= datastore['INTERFACE'] || ::Pcap.lookupdev
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@mymask ||= datastore['NETMASK'] || 24
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@mynet ||= lookupnet
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@mynet.include?(IPAddr.new(ip))
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end
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attr_accessor :capture, :arp_cache, :arp_capture, :dst_cache
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#Netifaces code
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# netifaces code is not available in pcaprub 0.9.2 and prior,
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# which is going to be installed in a lot of places. Modules
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# which want it should check explicitly for it. TODO: Bug upstream
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# to release it for real in 0.9.3
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def netifaces_implemented?
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@pcaprub_loaded and
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Pcap.respond_to?(:lookupaddrs) and
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Pcap.respond_to?(:interfaces) and
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Pcap.respond_to?(:addresses)
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end
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def list_interfaces
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check_pcaprub_loaded
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Pcap.interfaces
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end
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def is_interface?(dev)
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check_pcaprub_loaded
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if RUBY_PLATFORM == "i386-mingw32"
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if dev =~ /\\Device\\NPF_\{[A-F0-9]{8}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{12}\}/
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return Pcap.interfaces.include?(dev)
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elsif dev.to_s =~ /^[0-9]{1,2}$/
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if (dev.to_i <= Pcap.interfaces.length) and (dev.to_i >= 0)
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return true
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else
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return false
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end
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else
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return false
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end
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else
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return Pcap.interfaces.include?(dev)
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end
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end
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# This function is usefull only on windows where pcaprub use the GUID
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def get_interface_guid(dev)
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check_pcaprub_loaded
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if RUBY_PLATFORM == "i386-mingw32"
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if dev.to_s =~ /^[0-9]{1,2}$/
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if is_interface?(dev)
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Pcap.interfaces[(dev.to_i) - 1]
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else
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return dev
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end
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else
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return dev
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end
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else #Non windows
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return dev
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end
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end
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def get_mac(dev)
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check_pcaprub_loaded
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dev = get_interface_guid(dev)
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addrs = Pcap.addresses(dev)
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raise RuntimeError, "Interface #{dev} does not exist" if !addrs
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raise RuntimeError, "Can not get mac address for interface #{dev}" if !addrs[Pcap::AF_LINK][0]['addr']
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addrs[Pcap::AF_LINK][0]['addr']
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end
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def get_ipv4_addr_count(dev)
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check_pcaprub_loaded
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dev = get_interface_guid(dev)
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addrs = Pcap.addresses(dev)
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raise RuntimeError, "Interface #{dev} does not exist" if !addrs
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addrs[Pcap::AF_INET].length
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end
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def get_ipv4_addr(dev, num=0)
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check_pcaprub_loaded
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dev = get_interface_guid(dev)
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addrs = Pcap.addresses(dev)
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raise RuntimeError, "Interface #{dev} do not exists" if !addrs
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raise RuntimeError, "Interface #{dev} do not have an ipv4 address at position #{num}" if addrs[Pcap::AF_INET].length < num + 1
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raise RuntimeError, "Can not get the IPv4 address for interface #{dev}" if !addrs[Pcap::AF_INET][num]['addr']
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addrs[Pcap::AF_INET][num]['addr']
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end
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def get_ipv4_netmask(dev, num=0)
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check_pcaprub_loaded
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dev = get_interface_guid(dev)
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addrs = Pcap.addresses(dev)
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raise RuntimeError, "Interface #{dev} do not exists" if !addrs
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raise RuntimeError, "Interface #{dev} do not have an ipv4 address at position #{num}" if addrs[Pcap::AF_INET].length < num + 1
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raise RuntimeError, "Can not get IPv4 netmask for interface #{dev}" if !addrs[Pcap::AF_INET][num]['netmask']
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addrs[Pcap::AF_INET][num]['netmask']
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end
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def get_ipv4_broadcast(dev, num=0)
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check_pcaprub_loaded
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dev = get_interface_guid(dev)
|
|
addrs = Pcap.addresses(dev)
|
|
raise RuntimeError, "Interface #{dev} do not exists" if !addrs
|
|
raise RuntimeError, "Interface #{dev} do not have an ipv4 address at position #{num}" if addrs[Pcap::AF_INET].length < num + 1
|
|
raise RuntimeError, "Can not get IPv4 broadcast address for interface #{dev}" if !addrs[Pcap::AF_INET][num]['broadcast']
|
|
addrs[Pcap::AF_INET][num]['broadcast']
|
|
end
|
|
|
|
def get_ipv6_addr_count(dev)
|
|
check_pcaprub_loaded
|
|
dev = get_interface_guid(dev)
|
|
raise RuntimeError, "IPv6 information is not available on this platform" if not ::Pcap.const_defined?(:AF_INET6)
|
|
addrs = Pcap.addresses(dev)
|
|
raise RuntimeError, "Interface #{dev} do not exists" if !addrs
|
|
addrs[Pcap::AF_INET6].length
|
|
end
|
|
|
|
# NOTE: IPv6 is not implemented on Windows
|
|
def get_ipv6_addr(dev, num=0)
|
|
check_pcaprub_loaded
|
|
dev = get_interface_guid(dev)
|
|
raise RuntimeError, "IPv6 information is not available on this platform" if not ::Pcap.const_defined?(:AF_INET6)
|
|
addrs = Pcap.addresses(dev)
|
|
raise RuntimeError, "Interface #{dev} do not exists" if !addrs
|
|
raise RuntimeError, "Interface #{dev} do not have an ipv6 address at position #{num}" if addrs[Pcap::AF_INET6].length < num + 1
|
|
raise RuntimeError, "Can not get ipv6 address for interface #{dev}" if !addrs[Pcap::AF_INET6][num]['addr']
|
|
addrs[Pcap::AF_INET6][num]['addr'].gsub(/%(.)*$/,'')
|
|
end
|
|
|
|
def get_ipv6_netmask(dev, num=0)
|
|
check_pcaprub_loaded
|
|
dev = get_interface_guid(dev)
|
|
raise RuntimeError, "IPv6 information is not available on this platform" if not ::Pcap.const_defined?(:AF_INET6)
|
|
addrs = Pcap.addresses(dev)
|
|
raise RuntimeError, "Interface #{dev} do not exists" if !addrs
|
|
raise RuntimeError, "Interface #{dev} do not have an ipv6 address at position #{num}" if addrs[Pcap::AF_INET6].length < num + 1
|
|
raise RuntimeError, "Can not get ipv6 netmask address for interface #{dev}" if !addrs[Pcap::AF_INET6][num]['netmask']
|
|
addrs[Pcap::AF_INET6][num]['netmask']
|
|
end
|
|
|
|
# Protocol-specific encoding/decoding methods until more
|
|
# application protos get into PacketFu proper
|
|
|
|
# Intended to be used as the payload to an ICMP echo request's payload
|
|
def capture_icmp_echo_pack(id=nil,seq=nil,payload=nil)
|
|
id ||= rand(0x10000)
|
|
seq ||= rand(0x10000)
|
|
[id,seq,payload.to_s].pack("nna*")
|
|
end
|
|
|
|
# Decodes and ICMP echo request or response.
|
|
def capture_icmp_echo_unpack(data)
|
|
data.unpack("nna*")
|
|
end
|
|
|
|
end
|
|
|
|
end
|