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#! /usr/bin/env ruby
# --
# Copyright 2007 Nominet UK
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ++
# = NAME
#
# axfr - Perform a DNS zone transfer
#
# = SYNOPSIS
#
# axfr [ -fqs ] [ -D directory ] [ @nameserver ] zone
#
# = DESCRIPTION
#
# axfr performs a DNS zone transfer, prints each record to the standard
# output, and stores the zone to a file. If the zone has already been
# stored in a file, axfr will read the file instead of performing a
# zone transfer.
#
# Zones will be stored in a directory hierarchy. For example, the
# zone transfer for foo.bar.com will be stored in the file
# HOME/.dns-zones/com/bar/foo/axfr. The directory can be changed
# with the B<-D> option.
#
# This programs requires that the Storable module be installed.
#
# = OPTIONS
#
# * -f Force a zone transfer, even if the zone has already been stored
# in a file.
#
# * -q Be quiet -- don't print the records from the zone.
#
# * -s Perform a zone transfer if the SOA serial number on the nameserver
# is different than the serial number in the zone file.
#
# * -D directory Store zone files under I<directory> instead of the default directory (see "FILES")
#
# * nameserver Query nameserver instead of the default nameserver.
#
# = FILES
#
# * ${HOME}/.dns-zones Default directory for storing zone files.
#
# = AUTHOR
#
# Michael Fuhr <mike@fuhr.org>
#
unless (1..2).include?(ARGV.length)
puts "Usage: #{$0} [ -fqs ] [ -D directory ] [ @nameserver ] zone"
exit(-1)
end
require 'getoptLong'
require 'dnsruby'
# ------------------------------------------------------------------------------
# Read any command-line options and check syntax.
# ------------------------------------------------------------------------------
# getopts("fqsD:");
opts = GetoptLong.new(["-f", GetoptLong::NO_ARGUMENT],
["-q", GetoptLong::NO_ARGUMENT],
["-D", GetoptLong::REQUIRED_ARGUMENT],
["-s", GetoptLong::NO_ARGUMENT])
opt_q = false
opt_f = false
opt_s = false
opt_d = nil
opts.each do |opt, arg|
case opt
when '-q'
opt_q=true
when '-f'
opt_f = true
when '-s'
opt_s = true
when '-D'
opt_d = arg
end
end
# ------------------------------------------------------------------------------
# Get the nameserver (if specified) and set up the zone transfer directory
# hierarchy.
# ------------------------------------------------------------------------------
nameserver = (ARGV[0] =~ /^@/) ? ARGV.shift : ''
nameserver = nameserver.sub(/^@/, '')
resolver = nameserver ? Dnsruby::Resolver.new(nameserver) : Dnsruby::Resolver.new
zone = ARGV.shift
basedir = opt_d || File.join((ENV['HOME'] || ''), '.dns-zones')
zonedir = zone.split(/\./).reverse.join("/")
zonefile = File.join(basedir, zonedir, 'axfr')
# Don't worry about the 0777 permissions here - the current umask setting
# will be applied.
# NOTE: mkdir will raise an error on failure so I don't think 'or' works here.
unless FileTest.directory?(basedir)
Dir.mkdir(basedir, 0777) or raise RuntimeError, "can't mkdir #{basedir}: #{$!}\n"
end
dir = basedir
# NOTE: What are we doing here? Could this be replaced by mkdir_p?
zonedir.split('/').each do |subdir|
dir += '/' + subdir
unless FileTest.directory?(dir)
Dir.mkdir(dir, 0777) or raise RuntimeError, "can't mkdir #{dir}: #{$!}\n"
end
end
# ------------------------------------------------------------------------------
# Get the zone.
# ------------------------------------------------------------------------------
if FileTest.exist?(zonefile) && !opt_f
zoneref = Marshal.load(File.open(zonefile))
if zoneref.nil?
raise RuntimeError, "couldn't retrieve zone from #{zonefile}: #{$!}\n"
end
# ----------------------------------------------------------------------
# Check the SOA serial number if desired.
# ----------------------------------------------------------------------
if opt_s
serial_file = serial_zone = nil
zoneref.each do |rr|
if (rr.type == 'SOA')
serial_file = rr.serial
break
end
end
if serial_file.nil?
raise RuntimeError, "no SOA in #{zonefile}\n"
end
soa = resolver.query(zone, 'SOA')
if soa.nil?
raise RuntimeError, "couldn't get SOA for #{zone}: " + resolver.errorstring + "\n"
end
soa.answer.each do |rr|
if rr.type == 'SOA'
serial_zone = rr.serial
break
end
end
if serial_zone != serial_file
opt_f = true
end
end
else
opt_f = true
end
if opt_f
print "nameserver = #{nameserver}, zone=#{zone}"
zt = Dnsruby::ZoneTransfer.new
zt.server = nameserver if nameserver != ''
zoneref = zt.transfer(zone)
if zoneref.nil?
raise RuntimeError, "couldn't transfer zone\n"
end
Marshal.dump(zoneref, File.open(zonefile, File::CREAT | File::RDWR))
end
# ------------------------------------------------------------------------------
# Print the records in the zone.
# ------------------------------------------------------------------------------
unless opt_q
zoneref.each { |z| puts z }
end
|
