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PacketFu::IPPacket

IPPacket is used to construct IP packets. They contain an EthHeader, an IPHeader, and usually a transport-layer protocol such as UDPHeader, TCPHeader, or ICMPHeader.

Example

require 'packetfu'
ip_pkt = PacketFu::IPPacket.new
ip_pkt.ip_saddr="10.20.30.40"
ip_pkt.ip_daddr="192.168.1.1"
ip_pkt.ip_proto=1
ip_pkt.ip_ttl=64
ip_pkt.ip_payload="\x00\x00\x12\x34\x00\x01\x00\x01"+
  "Lovingly hand-crafted echo responses delivered directly to your door."
ip_pkt.recalc 
ip_pkt.to_f('/tmp/ip.pcap')

Parameters

:eth
  A pre-generated EthHeader object.
:ip
  A pre-generated IPHeader object.
:flavor
  TODO: Sets the "flavor" of the IP packet. This might include known sets of IP options, and
  certainly known starting TTLs.
:config
  A hash of return address details, often the output of Utils.whoami?

Attributes

eth_header[RW]
ip_header[RW]

Public Class Methods

can_parse?(str) click to toggle source
# File lib/packetfu/protos/ip.rb, line 42
def self.can_parse?(str)
        return false unless str.size >= 34
        return false unless EthPacket.can_parse? str
        if str[12,2] == "\x08\x00"
                if 1.respond_to? :ord
                        ipv = str[14,1][0].ord >> 4
                else
                        ipv = str[14,1][0] >> 4
                end
                return true if ipv == 4 
        else
                return false
        end
end
new(args={}) click to toggle source

Creates a new IPPacket object.

# File lib/packetfu/protos/ip.rb, line 65
def initialize(args={})
        @eth_header = EthHeader.new(args).read(args[:eth])
        @ip_header = IPHeader.new(args).read(args[:ip])
        @eth_header.body=@ip_header

        @headers = [@eth_header, @ip_header]
        super
end

Public Instance Methods

peek_format() click to toggle source

Peek provides summary data on packet contents.

# File lib/packetfu/protos/ip.rb, line 75
def peek_format
        peek_data = ["I  "]
        peek_data << "%-5d" % to_s.size
        peek_data << "%-21s" % "#{ip_saddr}"
        peek_data << "->"
        peek_data << "%21s" % "#{ip_daddr}"
        peek_data << "%23s" % "I:"
        peek_data << "%04x" % ip_id.to_i
        peek_data.join
end
read(str=nil, args={}) click to toggle source
# File lib/packetfu/protos/ip.rb, line 57
def read(str=nil, args={})
        raise "Cannot parse `#{str}'" unless self.class.can_parse?(str)
        @eth_header.read(str)
        super(args) 
        self
end

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