96 lines
3.1 KiB
Ruby
96 lines
3.1 KiB
Ruby
# $Id: vrrp.rb 127 2009-11-29 01:30:46Z jhart $
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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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module Racket
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module L4
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# Virtual Router Redundancy Protocol (VRRP)
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# http://tools.ietf.org/html/rfc2338
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# http://tools.ietf.org/html/rfc3768
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class VRRP < RacketPart
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# Version
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unsigned :version, 4
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# VRRP packet type
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unsigned :type, 4
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# Virtual Router Identifier (VRID)
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unsigned :id, 8
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# the sending VRRP router's priority for the virtual router.
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# Higher values equal higher priority.
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unsigned :priority, 8
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# Total number of IPs contained in this VRRP message
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unsigned :num_ips, 8
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# Authentication type (0, 1, 2)
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unsigned :auth_type, 8
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# Advertisement interval
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unsigned :interval, 8
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# Checksum
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unsigned :checksum, 16
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rest :payload
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# Add a new IP to this message
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def add_ip(ip)
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@ips << L3::Misc.ipv42long(ip)
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end
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# Add authentication data
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def add_auth(authdata)
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@authdata = authdata[0,8].ljust(32, "\x00")
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end
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# Validate the checksum
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def checksum?
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self.checksum == compute_checksum
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end
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# compute and set the checksum
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def checksum!
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self.checksum = compute_checksum
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end
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# (really, just set the checksum)
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def fix!
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self.payload = [@ips, @authdata].flatten.pack("N#{@ips.size}a*")
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self.num_ips = @ips.size
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self.checksum!
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end
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def initialize(*args)
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@ips = []
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@authdata = ""
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super
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end
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private
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def compute_checksum
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# pseudo header used for checksum calculation as per RFC 768
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pseudo = [ ((self.version << 4) | self.type), self.id, self.priority, self.num_ips, self.auth_type, self.interval, 0, self.payload ]
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L3::Misc.checksum(pseudo.pack("CCCCCCna*"))
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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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