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#!/usr/bin/ruby
# Copyright 2006, 2012, 2014 Peter Palfrader
# 2012 Uli Martens
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
# the each_resource function is lifted from ruby 1.9.1's resolv.rb, with the
# minor modification that we do not unconditionally set the message's RD flag
# to 1. Its license is:
#
# Copyright (C) 1993-2010 Yukihiro Matsumoto. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
require 'ipaddr'
require 'resolv'
require 'optparse'
require 'yaml'
NAGIOS_STATUS = { :OK => 0, :WARNING => 1, :CRITICAL => 2, :UNKNOWN => -1 };
@verbose = 0;
@additional_nameservers = []
@check_soa_nameservers = true;
def show_help(parser, code=0, io=STDOUT)
program_name = File.basename($0, '.*')
io.puts "Usage: #{program_name} [options] <domainname> [<domainname> ...]"
io.puts parser.summarize
exit(code)
end
ARGV.options do |opts|
opts.on_tail("-h", "--help" , "Display this help screen") { show_help(opts) }
opts.on("-v", "--verbose" , String, "Be verbose") { @verbose += 1 }
opts.on("-a", "--add=HOST" , String, "Also check SOA on <nameserver>") { |val| @additional_nameservers << val }
opts.on("-n", "--no-soa-ns" , String, "Don't query SOA record for list of nameservers") { @check_soa_nameservers = false }
opts.parse!
end
show_help(ARGV.options, 1, STDERR) if ARGV.length == 0
if @additional_nameservers.count <= 1 and not @check_soa_nameservers
program_name = File.basename($0, '.*')
STDERR.puts "#{program_name}: Only know about #{@additional_nameservers.count} nameserver(s) and --no-soa-ns specified. I want at least two."
exit(1)
end
class DSADNS < Resolv::DNS
attr_reader :rd
attr_writer :rd
def initialize(*args)
super
@rd = 1
end
def each_resource(name, typeclass, &proc)
lazy_initialize
requester = make_udp_requester
senders = {}
begin
@config.resolv(name) {|candidate, tout, nameserver, port|
msg = Message.new
msg.rd = @rd
msg.add_question(candidate, typeclass)
unless sender = senders[[candidate, nameserver, port]]
sender = senders[[candidate, nameserver, port]] =
requester.sender(msg, candidate, nameserver, port)
end
reply, reply_name = requester.request(sender, tout)
case reply.rcode
when RCode::NoError
if reply.tc == 1 and not Requester::TCP === requester
requester.close
# Retry via TCP:
requester = make_tcp_requester(nameserver, port)
senders = {}
# This will use TCP for all remaining candidates (assuming the
# current candidate does not already respond successfully via
# TCP). This makes sense because we already know the full
# response will not fit in an untruncated UDP packet.
redo
else
extract_resources(reply, reply_name, typeclass, &proc)
end
return
when RCode::NXDomain
raise Config::NXDomain.new(reply_name.to_s)
else
raise Config::OtherResolvError.new(reply_name.to_s)
end
}
ensure
requester.close
end
end
end
warnings = []
oks = []
def resolve_ns(dns, domain, nameserver)
puts "Getting A record for nameserver #{nameserver} for #{domain}" if @verbose > 0
arecords = dns.getresources(nameserver, Resolv::DNS::Resource::IN::A)
warnings << "Nameserver #{nameserver} for #{domain} has #{arecords.length} A records" if arecords.length != 1
addresses = arecords.map { |a| a.address.to_s }
puts "Addresses for nameserver #{nameserver} for #{domain}: #{addresses.join(', ')}" if @verbose > 0
return addresses
end
dns = Resolv::DNS.new
ARGV.each{ |domain|
serial = {}
nameserver_addresses = {}
if @check_soa_nameservers
nameservers = dns.getresources(domain, Resolv::DNS::Resource::IN::NS)
nameservernames = nameservers.collect{ |ns| ns.name.to_s }
nameservernames.each do |nameserver|
addrs = resolve_ns(dns, domain, nameserver)
warnings << "Duplicate nameserver #{nameserver} for #{domain}" if nameserver_addresses[nameserver]
nameserver_addresses[nameserver] = addrs
end
end
@additional_nameservers.each do |ns|
begin
ipa = IPAddr.new(ns) # check if it's an address
addrs = [ns]
rescue ArgumentError
addrs = resolve_ns(dns, domain, ns)
end
warnings << "Duplicate nameserver #{ns} for #{domain}" if nameserver_addresses[ns]
nameserver_addresses[ns] = addrs
end
nameserver_addresses.each_pair do |nameserver, addrs|
puts "Testing nameserver #{nameserver} for #{domain}" if @verbose > 0
addrs.each do |a|
puts " Nameserver #{nameserver} is at #{a}" if @verbose > 0
begin
resolver = DSADNS.new({:nameserver => a})
resolver.rd = 0
soas = resolver.getresources(domain, Resolv::DNS::Resource::IN::SOA)
rescue SystemCallError => e
warnings << "Could not resolve #{domain} on #{nameserver}: #{e.message}"
else
resolver.close
warnings << "Nameserver #{nameserver} for #{domain} returns #{soas.length} SOAs" if soas.length != 1
soas.each do |soa|
puts " Nameserver #{nameserver} returns serial #{soa.serial} for #{domain}" if @verbose > 0
sn = soa.serial.to_i
if serial.has_key? sn then
serial[sn] << nameserver
else
serial[sn] = [nameserver]
end
end
end
end
end
case serial.keys.length
when 0
warnings << "Found no serials for #{domain}"
when 1
oks << "#{domain} is at #{serial.keys.first}"
else
text = []
serial.keys.sort.each do |sn|
text << "#{sn} (#{serial[sn].join(', ')})"
end
warnings << "Nameservers disagree on serials for #{domain}: found #{text.join(', ')}"
end
}
dns.close
if warnings.length > 0
puts warnings.join('; ')
exit NAGIOS_STATUS[:WARNING]
else
puts oks.join('; ')
exit NAGIOS_STATUS[:OK]
end
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