plugins-scripts/check_netdns.pl

   1 #!/usr/bin/perl -w
   2
   3 # Perl version of check_dns plugin which calls DNS directly instead of
   4 # relying on nslookup (which has bugs)
   5 #
   6 # Copyright 2000, virCIO, LLP
   7 #
   8 # Revision 1.3  2002/05/07 05:35:49  sghosh
   9 # 2nd fix for ePN
  10 #
  11 # Revision 1.2  2002/05/02 16:43:29  sghosh
  12 # fix for embedded perl
  13 #
  14 # Revision 1.1.1.1  2002/02/28 06:43:00  egalstad
  15 # Initial import of existing plugin code
  16 #
  17 # Revision 1.1  2000/08/03 20:41:12  karldebisschop
  18 # rename to avoid conflict when installing
  19 #
  20 # Revision 1.1  2000/08/03 19:27:08  karldebisschop
  21 # use Net::DNS to check name server
  22 #
  23 # Revision 1.1  2000/07/20 19:09:13  cwg
  24 # All the pieces needed to use my version of check_dns.
  25 #
  26 #
  27
  28 use Getopt::Long;
  29 use Net::DNS;
  30 use lib utils.pm;
  31 use utils ;
  32
  33 my $PROGNAME = "check_netdns";
  34
  35 Getopt::Long::Configure(`bundling`);
  36 GetOptions("V" => $opt_V,         "version" => $opt_V,
  37                                          "h" => $opt_h,         "help" => $opt_h,
  38                                          "t=i" => $opt_t,       "timeout=i" => $opt_t,
  39                                          "s=s" => $opt_s,       "server=s" => $opt_s,
  40                                          "H=s" => $opt_H,       "hostname=s" => $opt_H);
  41
  42 # -h means display verbose help screen
  43 if($opt_h){ print_help(); exit 0; }
  44
  45 # -V means display version number
  46 if ($opt_V) { print_version(); exit 0; }
  47
  48 # -H means host name
  49 $opt_H = shift unless ($opt_H);
  50 unless ($opt_H) { print_usage(); exit -1; }
  51 if ($opt_H &&
  52                 $opt_H =~ m/^([0-9]+.[0-9]+.[0-9]+.[0-9]+|[a-zA-Z][-a-zA-Z0]+(.[a-zA-Z][-a-zA-Z0]+)*)$/)
  53 {
  54         $host = $1;
  55 } else {
  56         print "$opt_H is not a valid host name";
  57         exit -1;
  58 }
  59
  60 # -s means server name
  61 $opt_s = shift unless ($opt_s);
  62 if ($opt_s) {
  63         if ($opt_s =~ m/^([0-9]+.[0-9]+.[0-9]+.[0-9]+|[a-zA-Z][-a-zA-Z0]+(.[a-zA-Z][-a-zA-Z0]+)*)$/)
  64         {
  65                 $server = $1;
  66         } else {
  67                 print "$opt_s is not a valid host name";
  68                 exit -1;
  69         }
  70 }
  71
  72 # -t means timeout
  73 my $timeout = 10 unless ($opt_t);
  74
  75 my $res = new Net::DNS::Resolver;
  76 #$res->debug(1);
  77 if ($server) {
  78         $res->nameservers($server);
  79 }
  80
  81 $res->tcp_timeout($timeout);
  82 $SIG{ALRM} = &catch_alarm;
  83 alarm($timeout);
  84
  85 $query = $res->query($host);
  86 if ($query) {
  87         my @answer = $query->answer;
  88         if (@answer) {
  89                 print join(`/`, map {
  90                         $_->type . ` ` . $_->rdatastr;
  91                 } @answer);
  92                 exit 0;
  93         } else {
  94                 print "empty answer";
  95                 exit 2;
  96         }
  97 }
  98 else {
  99         print "query failed: ", $res->errorstring, "";
 100         exit 2;
 101 }
 102
 103 sub catch_alarm {
 104         print "query timed out";
 105         exit 2;
 106 }
 107
 108 sub print_version () {
 109         my $arg0 =  $0;
 110         chomp $arg0;
 111         print "$arg0                        version 0.1";
 112 }
 113 sub print_help() {
 114         print_version();
 115         print "";
 116         print "Check if a nameserver can resolve a given hostname.";
 117         print "";
 118         print_usage();
 119         print "";
 120         print "-H, --hostname=HOST";
 121         print "   The name or address you want to query";
 122         print "-s, --server=HOST";
 123         print "   Optional DNS server you want to use for the lookup";
 124         print "-t, --timeout=INTEGER";
 125         print "   Seconds before connection times out (default: 10)";
 126         print "-h, --help";
 127         print "   Print detailed help";
 128         print "-V, --version";
 129         print "   Print version numbers and license information";
 130 }
 131
 132 sub print_usage () {
 133         my $arg0 = $0;
 134         chomp $arg0;
 135         print "$arg0 check_dns -H host [-s server] [-t timeout]";
 136         print "$arg0 [-h | --help]";
 137         print "$arg0 [-V | --version]";
 138 }
 139