3 # Copyright 2006, 2012, 2014 Peter Palfrader
6 # Permission is hereby granted, free of charge, to any person obtaining
7 # a copy of this software and associated documentation files (the
8 # "Software"), to deal in the Software without restriction, including
9 # without limitation the rights to use, copy, modify, merge, publish,
10 # distribute, sublicense, and/or sell copies of the Software, and to
11 # permit persons to whom the Software is furnished to do so, subject to
12 # the following conditions:
14 # The above copyright notice and this permission notice shall be
15 # included in all copies or substantial portions of the Software.
17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 # the each_resource function is lifted from ruby 1.9.1's resolv.rb, with the
27 # minor modification that we do not unconditionally set the message's RD flag
28 # to 1. Its license is:
30 # Copyright (C) 1993-2010 Yukihiro Matsumoto. All rights reserved.
32 # Redistribution and use in source and binary forms, with or without
33 # modification, are permitted provided that the following conditions
35 # 1. Redistributions of source code must retain the above copyright
36 # notice, this list of conditions and the following disclaimer.
37 # 2. Redistributions in binary form must reproduce the above copyright
38 # notice, this list of conditions and the following disclaimer in the
39 # documentation and/or other materials provided with the distribution.
41 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
42 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 NAGIOS_STATUS = { :OK => 0, :WARNING => 1, :CRITICAL => 2, :UNKNOWN => -1 };
61 @additional_nameservers = []
62 @check_soa_nameservers = true;
64 def show_help(parser, code=0, io=STDOUT)
65 program_name = File.basename($0, '.*')
66 io.puts "Usage: #{program_name} [options] <domainname> [<domainname> ...]"
67 io.puts parser.summarize
70 ARGV.options do |opts|
71 opts.on_tail("-h", "--help" , "Display this help screen") { show_help(opts) }
72 opts.on("-v", "--verbose" , String, "Be verbose") { @verbose += 1 }
73 opts.on("-a", "--add=HOST" , String, "Also check SOA on <nameserver>") { |val| @additional_nameservers << val }
74 opts.on("-n", "--no-soa-ns" , String, "Don't query SOA record for list of nameservers") { @check_soa_nameservers = false }
77 show_help(ARGV.options, 1, STDERR) if ARGV.length == 0
79 if @additional_nameservers.count <= 1 and not @check_soa_nameservers
80 program_name = File.basename($0, '.*')
81 STDERR.puts "#{program_name}: Only know about #{@additional_nameservers.count} nameserver(s) and --no-soa-ns specified. I want at least two."
85 class DSADNS < Resolv::DNS
94 def each_resource(name, typeclass, &proc)
96 requester = make_udp_requester
99 @config.resolv(name) {|candidate, tout, nameserver, port|
102 msg.add_question(candidate, typeclass)
103 unless sender = senders[[candidate, nameserver, port]]
104 sender = senders[[candidate, nameserver, port]] =
105 requester.sender(msg, candidate, nameserver, port)
107 reply, reply_name = requester.request(sender, tout)
110 if reply.tc == 1 and not Requester::TCP === requester
113 requester = make_tcp_requester(nameserver, port)
115 # This will use TCP for all remaining candidates (assuming the
116 # current candidate does not already respond successfully via
117 # TCP). This makes sense because we already know the full
118 # response will not fit in an untruncated UDP packet.
121 extract_resources(reply, reply_name, typeclass, &proc)
125 raise Config::NXDomain.new(reply_name.to_s)
127 raise Config::OtherResolvError.new(reply_name.to_s)
139 def resolve_ns(dns, domain, nameserver)
140 puts "Getting A record for nameserver #{nameserver} for #{domain}" if @verbose > 0
141 arecords = dns.getresources(nameserver, Resolv::DNS::Resource::IN::A)
142 warnings << "Nameserver #{nameserver} for #{domain} has #{arecords.length} A records" if arecords.length != 1
143 addresses = arecords.map { |a| a.address.to_s }
144 puts "Addresses for nameserver #{nameserver} for #{domain}: #{addresses.join(', ')}" if @verbose > 0
148 dns = Resolv::DNS.new
151 nameserver_addresses = {}
152 if @check_soa_nameservers
153 nameservers = dns.getresources(domain, Resolv::DNS::Resource::IN::NS)
154 nameservernames = nameservers.collect{ |ns| ns.name.to_s }
155 nameservernames.each do |nameserver|
156 addrs = resolve_ns(dns, domain, nameserver)
157 warnings << "Duplicate nameserver #{nameserver} for #{domain}" if nameserver_addresses[nameserver]
158 nameserver_addresses[nameserver] = addrs
161 @additional_nameservers.each do |ns|
163 ipa = IPAddr.new(ns) # check if it's an address
166 addrs = resolve_ns(dns, domain, ns)
168 warnings << "Duplicate nameserver #{ns} for #{domain}" if nameserver_addresses[ns]
169 nameserver_addresses[ns] = addrs
172 nameserver_addresses.each_pair do |nameserver, addrs|
173 puts "Testing nameserver #{nameserver} for #{domain}" if @verbose > 0
175 puts " Nameserver #{nameserver} is at #{a}" if @verbose > 0
177 resolver = DSADNS.new({:nameserver => a})
179 soas = resolver.getresources(domain, Resolv::DNS::Resource::IN::SOA)
180 rescue SystemCallError => e
181 warnings << "Could not resolve #{domain} on #{nameserver}: #{e.message}"
184 warnings << "Nameserver #{nameserver} for #{domain} returns #{soas.length} SOAs" if soas.length != 1
186 puts " Nameserver #{nameserver} returns serial #{soa.serial} for #{domain}" if @verbose > 0
188 if serial.has_key? sn then
189 serial[sn] << nameserver
191 serial[sn] = [nameserver]
197 case serial.keys.length
199 warnings << "Found no serials for #{domain}"
201 oks << "#{domain} is at #{serial.keys.first}"
204 serial.keys.sort.each do |sn|
205 text << "#{sn} (#{serial[sn].join(', ')})"
207 warnings << "Nameservers disagree on serials for #{domain}: found #{text.join(', ')}"
212 if warnings.length > 0
213 puts warnings.join('; ')
214 exit NAGIOS_STATUS[:WARNING]
217 exit NAGIOS_STATUS[:OK]