#!/usr/bin/perl
#
#    Copyright (C) 2003-2011 Opsera Limited. All rights reserved
#
#    This file is part of Opsview
#
#    Opsview is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    Opsview is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with Opsview; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

use strict;
use lib qw ( /usr/local/nagios/perl/lib );
use Net::LDAP;
use Getopt::Std;

# About us
my $script             = "check_ldap_sync";
my $script_version     = "0.1";
my $script_description = "Ensures that specified LDAP servers are synchronised";

# Array of hostnames
my $master_hostname;
my $slave_hostname;

# Performance data
my $perfdata = "";

# Search to run
my $base_dn = "";
my $timeout = 30;    # Query timeout
my $elapsed = 0;

# Responses from servers
my $master_csn = "";
my $slave_csn  = "";

# Command line arguments
our ( $opt_h, $opt_H, $opt_m, $opt_t, $opt_b );
getopts("hH:m:t:b:");
if ($opt_h) {
    usage();
    exit 0;
}
if ($opt_H) {
    $slave_hostname = $opt_H;
}
else {
    print "No master hostname specified\n";
    usage();
    exit 3;
}
if ($opt_m) {
    $master_hostname = $opt_m;
}
else {
    print "No slave hostname specified\n";
    usage();
    exit 3;
}
if ($opt_t) {

    # Validity test - must be numeric
    unless ( $opt_t =~ /^[0-9]+$/ ) {
        print "Specify timeout in seconds - $opt_t is not a valid integer\n";
        exit 3;
    }
    $timeout = $opt_t;
}
if ($opt_b) {
    $base_dn = $opt_b;
}
else {
    print "You must specify the base DN\n";
    exit 3;
}

sub quit_err {
    print "UNKNOWN: $@\n";
    exit 3;
}

sub usage {
    print <<EOF
--------------------------------------------------------------------
$script $script_version

$script_description

Usage: $script -H <master_hostname> -m <slave_hostname> -b <basedn> ...

Options: -H     Hostname of slave LDAP server to check
         -m     Master LDAP server address (for contextCSN comparison)
         -b     Base DN of LDAP directory
         -t     LDAP search query timeout

--------------------------------------------------------------------     
Copyright 2007 Altinity Limited  
         
This program is free software; you can redistribute it or modify
it under the terms of the GNU General Public License
------------------------------------------------------------------
EOF

}

# getContextCSN(host, basedn)
sub getContextCSN {
    my $hostname = shift(@_);
    my $base     = shift(@_);
    my $contextCSN;
    my $entry = "";

    my $ldap = Net::LDAP->new( $hostname, timeout => $timeout ) or quit_err($@);
    my $mesg = $ldap->bind();
    $mesg = $ldap->search(
        base   => "$base",
        scope  => 'base',
        filter => '(objectclass=*)',
        attrs  => ['contextCSN']
    );

    if ( $mesg->{'resultCode'} ) {
        print "UNKNOWN - base $base_dn not found on $hostname\n";
        exit 3;
    }

    $mesg->code && die $mesg->error;
    foreach $entry ( $mesg->entries ) {
        if ( $entry->{'asn'}->{'objectName'} eq $base ) {
            $contextCSN = $entry->{'asn'}->{'attributes'}[0]->{'vals'}[0];
        }
        else {
            print "Unexpected object: " . $entry->{'asn'}->{'objectName'} . "\n";
        }
    }
    $mesg = $ldap->unbind;    # take down session

    return $contextCSN;
}

$master_csn = getContextCSN( $master_hostname, $base_dn );
if ( $master_csn eq "" ) {

    # With OpenLDAP this could be missing syncprov overlay
    print "UNKNOWN - Master did not return a contextCSN for $base_dn, cannot continue.\n";
    exit 3;
}

$slave_csn = getContextCSN( $slave_hostname, $base_dn );
if ( $slave_csn eq "" ) {
    print "UNKNOWN - Slave did not return a contextCSN for $base_dn, cannot continue.\n";
    exit 3;
}

if ( $master_csn != $slave_csn ) {
    print "CRITICAL - $master_hostname and $slave_hostname are not in sync!\n";
    exit 2;
}

print "OK - $master_hostname and $slave_hostname are in sync\n";
exit 0