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scripts-admin-quickndirty-p.../nagios/check_zone_rrsig_expiration

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8.3 KiB
Perl
Executable file

#!/usr/bin/perl
# $Id: check_zone_rrsig_expiration,v 1.14 2015/10/12 16:54:20 wessels Exp $
#
# check_zone_rrsig_expiration
#
# nagios plugin to check expiration times of RRSIG records. Reminds
# you if its time to re-sign your zone.
# Copyright (c) 2008, The Measurement Factory, Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 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.
# Neither the name of The Measurement Factory nor the names of its
# contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
# COPYRIGHT OWNER 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.
# usage
#
# define command {
# command_name check-zone-rrsig
# command_line /usr/local/libexec/nagios-local/check_zone_rrsig -Z $HOSTADDRESS$
# }
#
# define service {
# name dns-rrsig-service
# check_command check-zone-rrsig
# ...
# }
#
# define host {
# use dns-zone
# host_name zone.example.com
# alias ZONE example.com
# }
#
# define service {
# use dns-rrsig-service
# host_name zone.example.com
# }
use warnings;
use strict;
use Getopt::Std;
use Net::DNS::Resolver;
use Time::HiRes qw ( gettimeofday tv_interval);
use Time::Local;
use List::Util qw ( shuffle );
# options
# -Z zone Zone to test
# -t seconds DNS query timeout
# -d debug
# -C days Critical if expiring in this many days
# -W days Warning if expiring in this many days
# -T type Query type (default SOA)
# -4 use IPv4 only
# -U size EDNS0 UDP packet size (default 4096)
my %opts = (t=>30, C=>2, W=>3, T=>'SOA', U=>4096);
getopts('4Z:dt:W:C:T:U:', \%opts);
usage() unless $opts{Z};
usage() if $opts{h};
my $zone = $opts{Z};
$zone =~ s/^zone\.//;
my $data;
my $start;
my $stop;
my @refs = qw (
a.root-servers.net
b.root-servers.net
c.root-servers.net
d.root-servers.net
e.root-servers.net
f.root-servers.net
g.root-servers.net
h.root-servers.net
i.root-servers.net
j.root-servers.net
k.root-servers.net
l.root-servers.net
m.root-servers.net
);
$start = [gettimeofday()];
do_recursion();
do_queries();
$stop = [gettimeofday()];
do_analyze();
sub do_recursion {
my $done = 0;
my $res = Net::DNS::Resolver->new;
do {
print STDERR "\nRECURSE\n" if $opts{d};
my $pkt;
foreach my $ns (shuffle @refs) {
print STDERR "sending query for $zone $opts{T} to $ns\n" if $opts{d};
$res->nameserver($ns);
$res->udp_timeout($opts{t});
$res->recurse(0);
$res->dnssec(1);
$res->udppacketsize($opts{U});
$res->force_v4(1) if $opts{'4'};
$pkt = $res->send($zone, $opts{T});
last if $pkt;
}
critical("No response to seed query") unless $pkt;
critical($pkt->header->rcode . " from " . $pkt->answerfrom)
unless ($pkt->header->rcode eq 'NOERROR');
@refs = ();
foreach my $rr ($pkt->authority) {
next unless $rr->type eq 'NS';
print STDERR $rr->string, "\n" if $opts{d};
push (@refs, $rr->nsdname);
next unless names_equal($rr->name, $zone);
add_nslist_to_data($pkt);
$done = 1;
}
} while (! $done);
}
sub do_queries {
my $n;
do {
$n = 0;
foreach my $ns (keys %$data) {
next if $data->{$ns}->{done};
print STDERR "\nQUERY $ns\n" if $opts{d};
my $pkt = send_query($zone, $opts{T}, $ns);
add_nslist_to_data($pkt);
$data->{$ns}->{queries}->{$opts{T}} = $pkt;
print STDERR "done with $ns\n" if $opts{d};
$data->{$ns}->{done} = 1;
$n++;
}
} while ($n);
}
sub do_analyze {
my $nscount = 0;
my $NOW = time;
my %MAX_EXP_BY_TYPE;
foreach my $ns (keys %$data) {
print STDERR "\nANALYZE $ns\n" if $opts{d};
my $pkt = $data->{$ns}->{queries}->{$opts{T}};
critical("No response from $ns") unless $pkt;
print STDERR $pkt->string if $opts{d};
critical($pkt->header->rcode . " from $ns")
unless ($pkt->header->rcode eq 'NOERROR');
critical("$ns is lame") unless $pkt->header->ancount;
foreach my $rr ($pkt->answer) {
next unless $rr->type eq 'RRSIG';
my $exp = sigrr_exp_epoch($rr);
my $T = $rr->typecovered;
if (!defined($MAX_EXP_BY_TYPE{$T}->{exp}) || $exp > $MAX_EXP_BY_TYPE{$T}->{exp}) {
$MAX_EXP_BY_TYPE{$T}->{exp} = $exp;
$MAX_EXP_BY_TYPE{$T}->{ns} = $ns;
}
}
$nscount++;
}
warning("No nameservers found. Is '$zone' a zone?") if ($nscount < 1);
warning("No RRSIGs found") unless %MAX_EXP_BY_TYPE;
my $min_exp = undef;
my $min_ns = undef;
my $min_type = undef;
foreach my $T (keys %MAX_EXP_BY_TYPE) {
printf STDERR ("%s RRSIG expires in %.1f days\n", $T, ($MAX_EXP_BY_TYPE{$T}->{exp}-$NOW)/86400) if $opts{d};
if (!defined($min_exp) || $MAX_EXP_BY_TYPE{$T}->{exp} < $min_exp) {
$min_exp = $MAX_EXP_BY_TYPE{$T}->{exp};
$min_ns = $MAX_EXP_BY_TYPE{$T}->{ns};
$min_type = $T;
}
}
critical("$min_ns has expired RRSIGs") if ($min_exp < $NOW);
if ($min_exp - $NOW < ($opts{C}*86400)) {
my $ND = sprintf "%3.1f days", ($min_exp-$NOW)/86400;
critical("$min_type RRSIG expires in $ND at $min_ns")
}
if ($min_exp - $NOW < ($opts{W}*86400)) {
my $ND = sprintf "%3.1f days", ($min_exp-$NOW)/86400;
warning("$min_type RRSIG expires in $ND at $min_ns")
}
success("No RRSIGs expiring in the next $opts{W} days");
}
sub sigrr_exp_epoch {
my $rr = shift;
die unless $rr->type eq 'RRSIG';
my $exp = $rr->sigexpiration;
die "bad exp time '$exp'"
unless $exp =~ /^(\d\d\d\d)(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/;
my $exp_epoch = timegm($6,$5,$4,$3,$2-1,$1);
return $exp_epoch;
}
sub add_nslist_to_data {
my $pkt = shift;
foreach my $ns (get_nslist($pkt)) {
next if defined $data->{$ns}->{done};
print STDERR "adding NS $ns\n" if $opts{d};
$data->{$ns}->{done} |= 0;
}
}
sub success {
output('OK', shift);
exit(0);
}
sub warning {
output('WARNING', shift);
exit(1);
}
sub critical {
output('CRITICAL', shift);
exit(2);
}
sub output {
my $state = shift;
my $msg = shift;
$stop = [gettimeofday()] unless $stop;
my $latency = tv_interval($start, $stop);
printf "ZONE %s: %s; (%.2fs) |time=%.6fs;;;0.000000\n",
$state,
$msg,
$latency,
$latency;
}
sub usage {
print STDERR "usage: $0 -Z zone -d -t timeout -W days -C days\n";
print STDERR "\t-Z zone zone to test\n";
print STDERR "\t-T type query type (default SOA)\n";
print STDERR "\t-d debug\n";
print STDERR "\t-t seconds timeout on DNS queries\n";
print STDERR "\t-W days warning threshhold\n";
print STDERR "\t-C days critical threshold\n";
print STDERR "\t-4 use IPv4 only\n";
print STDERR "\t-U bytes EDNS0 UDP buffer size (default 4096)\n";
exit 3;
}
sub send_query {
my $qname = shift;
my $qtype = shift;
my $server = shift;
my $res = Net::DNS::Resolver->new;
$res->nameserver($server) if $server;
$res->udp_timeout($opts{t});
$res->retry(2);
$res->recurse(0);
$res->dnssec(1);
$res->udppacketsize($opts{U});
$res->force_v4(1) if $opts{'4'};
my $pkt = $res->send($qname, $qtype);
unless ($pkt) {
$res->usevc(1);
$res->tcp_timeout($opts{t});
$pkt = $res->send($qname, $qtype);
}
return $pkt;
}
sub get_nslist {
my $pkt = shift;
return () unless $pkt;
return () unless $pkt->authority;
my @nslist;
foreach my $rr ($pkt->authority) {
next unless ($rr->type eq 'NS');
next unless names_equal($rr->name, $zone);
push(@nslist, lc($rr->nsdname));
}
return @nslist;
}
sub names_equal {
my $a = shift;
my $b = shift;
$a =~ s/\.$//;
$b =~ s/\.$//;
lc($a) eq lc($b);
}