167 lines
5.6 KiB
Ruby
167 lines
5.6 KiB
Ruby
# $Id: misc.rb 14 2008-03-02 05:42:30Z warchild $
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#
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# Copyright (c) 2008, Jon Hart
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are met:
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# * Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# * Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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# * Neither the name of the <organization> nor the
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# names of its contributors may be used to endorse or promote products
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# derived from this software without specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY Jon Hart ``AS IS'' AND ANY
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# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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# DISCLAIMED. IN NO EVENT SHALL Jon Hart BE LIABLE FOR ANY
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# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#
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require 'ipaddr'
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module Racket
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module L3
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# Miscelaneous L3 helper methods
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module Misc
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# given an IPv4 address packed as an integer
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# return the friendly "dotted quad"
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def Misc.long2ipv4(long)
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quad = Array.new(4)
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quad[0] = (long >> 24) & 255
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quad[1] = (long >> 16) & 255
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quad[2] = (long >> 8 ) & 255
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quad[3] = long & 255
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quad.join(".")
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end
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def Misc.randomipv4
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Misc.long2ipv4(rand(2**32))
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end
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# Compute link local address for a given mac address
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# From Daniele Bellucci
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def Misc.linklocaladdr(mac)
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mac = mac.split(":")
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mac[0] = (mac[0].to_i(16) ^ (1 << 1)).to_s(16)
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["fe80", "", mac[0,2].join, mac[2,2].join("ff:fe"), mac[4,2].join].join(":")
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end
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# Given a long, convert it to an IPv6 address,
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# optionally compressing the address returned
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def Misc.long2ipv6(long, compress=true)
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ipv6 = []
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ipv6[0] = long >> 112
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ipv6[1] = (long >> 96) & (0xFFFF)
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ipv6[2] = (long >> 80) & (0xFFFF)
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ipv6[3] = (long >> 64) & (0xFFFF)
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ipv6[4] = (long >> 48) & (0xFFFF)
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ipv6[5] = (long >> 32) & (0xFFFF)
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ipv6[6] = (long >> 16) & (0xFFFF)
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ipv6[7] = long & (0xFFFF)
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ipv6 = ipv6.map { |o| o.to_s(16) }.join(":")
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compress ? Misc.compressipv6(ipv6) : ipv6
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end
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# Compress an IPv6 address
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# Inspired by Daniele Bellucci and jacked from ipaddr
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def Misc.compressipv6(ipv6)
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ipv6.gsub!(/\b0{1,3}([\da-f]+)\b/i, '\1')
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loop do
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break if ipv6.sub!(/\A0:0:0:0:0:0:0:0\Z/, '::')
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break if ipv6.sub!(/\b0:0:0:0:0:0:0\b/, ':')
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break if ipv6.sub!(/\b0:0:0:0:0:0\b/, ':')
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break if ipv6.sub!(/\b0:0:0:0:0\b/, ':')
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break if ipv6.sub!(/\b0:0:0:0\b/, ':')
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break if ipv6.sub!(/\b0:0:0\b/, ':')
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break if ipv6.sub!(/\b0:0\b/, ':')
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break
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end
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ipv6.sub!(/:{3,}/, '::')
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if /\A::(ffff:)?([\da-f]{1,4}):([\da-f]{1,4})\Z/i =~ ipv6
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ipv6 = sprintf('::%s%d.%d.%d.%d', $1, $2.hex / 256, $2.hex % 256, $3.hex / 256, $3.hex % 256)
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end
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ipv6
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end
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def Misc.randomipv6
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Misc.long2ipv6(rand(2**128))
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end
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# given a string representing an IPv6
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# address, return the integer representation
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def Misc.ipv62long(ip)
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IPAddr.new(ip).to_i
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end
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# In addition to the regular multicast addresses, each unicast address
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# has a special multicast address called its solicited-node address. This
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# address is created through a special mapping from the device’s unicast
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# address. Solicited-node addresses are used by the IPv6 Neighbor
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# Discovery (ND) protocol to provide more efficient address resolution
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# than the ARP technique used in IPv4.
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# From Daniele Bellucci
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def Misc.soll_mcast_addr6(addr)
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h = addr.split(':')[-2, 2]
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m = []
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m << 'ff'
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m << (h[0].to_i(16) & 0xff).to_s(16)
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m << ((h[1].to_i(16) & (0xff << 8)) >> 8).to_s(16)
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m << (h[1].to_i(16) & 0xff).to_s(16)
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'ff02::1:' + [m[0,2].join, m[2,2].join].join(':')
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end
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#
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def Misc.soll_mcast_mac(addr)
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h = addr.split(':')[-2, 2]
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m = []
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m << 'ff'
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m << (h[0].to_i(16) & 0xff).to_s(16)
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m << ((h[1].to_i(16) & (0xff << 8)) >> 8).to_s(16)
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m << (h[1].to_i(16) & 0xff).to_s(16)
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'33:33:' + m.join(':')
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end
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# given a "dotted quad" representing an IPv4
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# address, return the integer representation
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def Misc.ipv42long(ip)
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IPAddr.new(ip).to_i
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end
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# Calculate the checksum. 16 bit one's complement of the one's
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# complement sum of all 16 bit words
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def Misc.checksum(data)
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num_shorts = data.length / 2
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checksum = 0
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count = data.length
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data.unpack("S#{num_shorts}").each { |x|
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checksum += x
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count -= 2
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}
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if (count == 1)
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checksum += data[data.length - 1, 1].unpack('C')[0]
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end
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checksum = (checksum >> 16) + (checksum & 0xffff)
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checksum = ~((checksum >> 16) + checksum) & 0xffff
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([checksum].pack("S*")).unpack("n*")[0]
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end
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end
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end
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end
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# vim: set ts=2 et sw=2:
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