155 lines
3.9 KiB
Ruby
155 lines
3.9 KiB
Ruby
# -*- coding: binary -*-
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require 'socket'
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require 'ipaddr'
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class RawSocket # :nodoc:
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@@id_arr = []
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def initialize(src_addr,dest_addr)
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# Define socket
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begin
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@socket = Socket.new PF_INET, SOCK_RAW, IPPROTO_RAW
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rescue SystemCallError => e
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raise SystemCallError, "You must be root to use raw sockets! #{e}"
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end
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@socket.setsockopt IPPROTO_IP, IP_HDRINCL, 1
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# Checks addresses
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@src_addr = check_addr src_addr
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@dest_addr = check_addr dest_addr
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# Source and destination port are zero
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@src_port = 0
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@dest_port = 0
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# Set correct protocol version in the header
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@version = @dest_addr.ipv4? ? "0100" : "0110"
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# Total lenght: must be overridden by subclasses
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@tot_lenght = 20
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# Protocol: must be overridden by subclasses
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@protocol = 1 # ICMP by default
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# Generate a new id
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# @id = genID
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@id = 1234
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# Generate peer sockaddr
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@to = Socket.pack_sockaddr_in @dest_port, @dest_addr.to_s
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end
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def send(payload = '')
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packet = make_ip_header([[ @version+'0101', 'B8' ], # version, hlen
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[ 0, 'C' ], # tos
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[ @tot_lenght + payload.size, 'n' ], # total len
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[ @id, 'n' ], # id
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[ 0, 'n' ], # flags, offset
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[ 64, 'C' ], # ttl
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[ @protocol, 'C' ], # protocol
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[ 0, 'n' ], # checksum
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[ @src_addr.to_i, 'N' ], # source
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[ @dest_addr.to_i, 'N' ], # destination
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])
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packet << make_transport_header(payload.size)
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packet << [payload].pack("a*")
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@socket.send(packet,0,@to)
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end
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private
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def check_addr addr
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case addr
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when String
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IPAddr.new addr
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when IPAddr
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addr
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else
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raise ArgumentError, "Wrong address format: #{addr}"
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end
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end
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def check_port port
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if (1..65535).include? port and port.kind_of? Integer
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port
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else
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raise ArgumentError, "Port #{port} not valid"
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end
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end
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def genID
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while (@@id_arr.include?(q = rand(65535)))
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end
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@@id_arr.push(q)
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q
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end
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def ipchecksum(data)
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checksum = data.unpack("n*").inject(0) { |s, x| s + x }
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((checksum >> 16) + (checksum & 0xffff)) ^ 0xffff
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end
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def make_ip_header(parts)
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template = ''
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data = []
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parts.each do |part|
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data += part[0..-2]
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template << part[-1]
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end
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data_str = data.pack(template)
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checksum = ipchecksum(data_str)
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data[-3] = checksum
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data.pack(template)
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end
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def make_transport_header
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""
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end
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end
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class UdpRawSocket < RawSocket # :nodoc:
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def initialize(src_addr,src_port,dest_addr,dest_port)
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super(src_addr,dest_addr)
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# Check ports
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@src_port = check_port src_port
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@dest_port = check_port dest_port
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# Total lenght: must be overridden by subclasses
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@tot_lenght = 20 + 8 # 8 bytes => UDP Header
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# Protocol: must be overridden by subclasses
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@protocol = 17 # UDP protocol
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@to = Socket.pack_sockaddr_in @dest_port, @dest_addr.to_s
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end
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private
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def make_udp_header(parts)
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template = ''
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data = []
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parts.each do |part|
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data += part[0..-2]
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template << part[-1]
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end
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data.pack(template)
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end
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def make_transport_header(pay_size)
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make_udp_header([
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[ @src_port, 'n'], # source port
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[ @dest_port, 'n' ], # destination port
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[ 8 + pay_size, 'n' ], # len
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[ 0, 'n' ] # checksum (mandatory)
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])
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end
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end
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