metasploit-framework/lib/packetfu/utils.rb

127 lines
5.2 KiB
Ruby

require 'singleton'
module PacketFu
# Utils is a collection of various and sundry network utilities that are useful for packet
# manipulation.
class Utils
include Singleton
# Returns the MAC address of an IP address, or nil if it's not responsive to arp. Takes
# a dotted-octect notation of the target IP address, as well as a number of parameters:
#
# === Parameters
# :eth_saddr
# Source MAC address. Defaults to "00:00:00:00:00:00".
# :ip_saddr
# Source IP address. Defaults to "0.0.0.0"
# :flavor
# The flavor of the ARP request. Defaults to :none.
# :timeout
# Timeout in seconds. Defaults to 3.
#
# === Example
# PacketFu::Utils::arp("192.168.1.1") #=> "00:18:39:01:33:70"
# PacketFu::Utils::arp("192.168.1.1", :timeout => 5, :flavor => :hp_deskjet)
#
# === Warning
#
# It goes without saying, spewing forged ARP packets on your network is a great way to really
# irritate your co-workers.
def self.arp(target_ip,args={})
arp_pkt = PacketFu::ARPPacket.new(:flavor => (args[:flavor] || :none))
arp_pkt.eth_saddr = arp_pkt.arp_saddr_mac = (args[:eth_saddr] || ($packetfu_default.config[:eth_saddr] if $packetfu_default) || "00:00:00:00:00:00" )
arp_pkt.eth_daddr = "ff:ff:ff:ff:ff:ff"
arp_pkt.arp_daddr_mac = "00:00:00:00:00:00"
arp_pkt.arp_saddr_ip = (args[:ip_saddr] || ($packetfu_default.config[:ip_saddr] if $packetfu_default) || "0.0.0.0")
arp_pkt.arp_daddr_ip = target_ip
iface = (args[:iface] || ($packetfu_default.iface if $packetfu_default) || "eth0")
# Stick the Capture object in its own thread.
cap_thread = Thread.new do
target_mac = nil
cap = PacketFu::Capture.new(:iface => iface, :start => true,
:filter => "arp src #{target_ip} and ether dst #{arp_pkt.eth_saddr}")
arp_pkt.to_w(iface) # Shorthand for sending single packets to the default interface.
timeout = 0
while target_mac.nil? && timeout <= (args[:timeout] || 3)
if cap.save > 0
arp_response = PacketFu::Packet.parse(cap.array[0])
target_mac = arp_response.arp_saddr_mac if arp_response.arp_saddr_ip = target_ip
end
timeout += 0.1
sleep 0.1 # Check for a response ten times per second.
end
target_mac
end # cap_thread
cap_thread.value
end # def self.arp
# Discovers the local IP and Ethernet address, which is useful for writing
# packets you expect to get a response to. Note, this is a noisy
# operation; a UDP packet is generated and dropped on to the default (or named)
# interface, and then captured (which means you need to be root to do this).
#
# whoami? returns a hash of :eth_saddr, :eth_src, :ip_saddr, :ip_src,
# :eth_dst, and :eth_daddr (the last two are usually suitable for a
# gateway mac address). It's most useful as an argument to PacketFu::Config.new.
#
# === Parameters
# :iface => "eth0"
# An interface to listen for packets on. Note that since we rely on the OS to send the probe packet,
# you will need to specify a target which will use this interface.
# :target => "1.2.3.4"
# A target IP address. By default, a packet will be sent to a random address in the 177/8 network.
# Since this network is IANA reserved (for now), this network should be handled by your default gateway
# and default interface.
def self.whoami?(args={})
if args[:iface] =~ /^lo/ # Linux loopback more or less. Need a switch for windows loopback, too.
dst_host = "127.0.0.1"
else
dst_host = (args[:target] || IPAddr.new((rand(16777216) + 2969567232), Socket::AF_INET).to_s)
end
dst_port = rand(0xffff-1024)+1024
msg = "PacketFu whoami? packet #{(Time.now.to_i + rand(0xffffff)+1)}"
cap = Capture.new(:iface => (args[:iface] || Pcap.lookupdev), :start => true, :filter => "udp and dst host #{dst_host} and dst port #{dst_port}")
UDPSocket.open.send(msg,0,dst_host,dst_port)
cap.save
pkt = Packet.parse(cap.array[0]) unless cap.save.zero?
timeout = 0
while timeout < 1 # Sometimes packet generation can be a little pokey.
if pkt
timeout = 1.1 # Cancel the timeout
if pkt.payload == msg
my_data = {
:iface => args[:iface] || Pcap.lookupdev || 'lo',
:pcapfile => args[:pcapfile] || "/tmp/out.pcap",
:eth_saddr => pkt.eth_saddr,
:eth_src => pkt.eth_src.to_s,
:ip_saddr => pkt.ip_saddr,
:ip_src => pkt.ip_src.to_s,
:eth_dst => pkt.eth_dst.to_s,
:eth_daddr => pkt.eth_daddr
}
else raise SecurityError,
"whoami() packet doesn't match sent data. Something fishy's going on."
end
else
sleep 0.1; timeout += 0.1
cap.save
pkt = Packet.parse(cap.array[0]) unless cap.save.zero?
end
raise SocketError, "Didn't recieve the whomi() packet." if !pkt
cap = nil
end
my_data
end
# This is a brute-force approach at trying to find a suitable interface with an IP address.
def self.lookupdev
# XXX cycle through eth0-9 and wlan0-9, and if a cap start throws a RuntimeErorr (and we're
# root), it's not a good interface. Boy, really ought to fix lookupdev directly with another
# method that returns an array rather than just the first candidate.
end
end # class Utils
end # module PacketFu