monitorix

#!/usr/bin/env perl
#
# Monitorix - A lightweight system monitoring tool.
#
# Copyright (C) 2005-2020 by Jordi Sanfeliu <jordi@fibranet.cat>
#
# This program 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.
#
# This program 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 this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

require 5.006;

use strict;
use warnings;
use FindBin qw($Bin);
use lib $Bin . "/lib", "/usr/lib/monitorix";

use Monitorix;
use POSIX qw(WNOHANG LC_TIME setlocale uname pause setsid);
use Config::General;
use Getopt::Std;
use Cwd qw(abs_path);

# Force a standard locale
$ENV{LANG} = "";
setlocale(LC_TIME, "C");

$SIG{'INT' } = 'INT_handler';
$SIG{'ABRT'} = 'INT_handler';
$SIG{'QUIT'} = 'INT_handler';
$SIG{'TRAP'} = 'INT_handler';
$SIG{'STOP'} = 'INT_handler';
$SIG{'TERM'} = 'INT_handler';
$SIG{'HUP' } = 'HUP_handler';

use constant VERSION	=> "3.12.0";
use constant RELDATE	=> "21-Feb-2020";

my @suppsys = ("Linux", "FreeBSD", "OpenBSD", "NetBSD");
our %config;
our %options;

sub INT_handler {
	my ($signal) = @_;

	logger("SIG$signal caught.");
	flush_accounting_rules(\%config, $options{d});
	if(lc($config{httpd_builtin}->{enabled} || "") eq "y") {
		kill(15, $config{httpd_pid});
	}
	logger("Exiting.");
	exit(0);
}

sub HUP_handler {
	my ($signal) = @_;
	my $myself = (caller(0))[3];

	return if $options{n};	# only continue if it's a daemon

	my (undef, undef, $uid) = getpwnam($config{httpd_builtin}->{user});
	my (undef, undef, $gid) = getgrnam($config{httpd_builtin}->{group});

	logger("SIG$signal caught.");

	# upon receiving SIGHUP a new logfile is opened
	close(STDOUT);
	close(STDERR);
	open(STDOUT, ">> $config{log_file}") || logger("Can't write to LOG: $!");
	open(STDERR, ">> $config{log_file}") || logger("Can't write to LOG: $!");
	chmod(0600, $config{log_file});
	logger("$myself: opening a new log file.");

	# restart HTTP built-in
	if(lc($config{httpd_builtin}->{enabled} || "") eq "y") {
		if(defined($config{httpd_pid})) {
			require HTTPServer;
			kill(15, $config{httpd_pid});
			kill(9, $config{httpd_pid});
			httpd_setup(\%config, $options{d});
			logger("Restarted HTTP built-in server (pid $config{httpd_pid}).") if (defined($config{httpd_pid}));
		}
	}
}

sub daemonize {
	open(STDIN, "< /dev/null") || die "Can't read /dev/null: $!";
	open(STDOUT, ">> $config{log_file}") || die "Can't write to LOG: $!";
	umask(022) || die "Unable to umask 022: $!";
	exit if fork();	# parent exits
	(setsid() != -1) || die "Can't start a new session: $!";
	open(STDERR, ">> $config{log_file}") || die "Can't write to LOG: $!";
}

sub usage {
	print(STDERR << "EOF");
Usage: monitorix -c configfile [-p pidfile] [-d none | graph[,graph] | all ] [-v] [-n]

EOF
	exit(1);
}

sub create_index {
	my $myself = (caller(0))[3];

	my $n;
	my $gname;
	my $bgcolor;
	my $table_back_color;
	my $title_back_color;
	my $title_fore_color;
	my $piwik_code = "";
	my ($piwik_url, $piwik_sid, $piwik_img);
	my $text_when_all;
	my $value_when_all;
	my $when_all_code = "";

	# keep backwards compatibility for v3.2.1 and less
	if(ref($config{theme}) ne "HASH") {
		logger("$myself: WARNING: the <theme> option is not valid. Please consider upgrading your configuration file. Defaulting to white theme.");
		delete($config{theme});
		$config{theme}->{white}->{main_bg} = "FFFFFF";
		$config{theme}->{white}->{main_fg} = "000000";
		$config{theme}->{white}->{title_bg} = "777777";
		$config{theme}->{white}->{title_fg} = "CCCC00";
		$config{theme}->{white}->{graph_bg} = "CCCCCC";
		$config{theme_color} = "white";
	}

	my $theme = $config{theme_color} || "white";
	if(!$config{theme}->{$theme}) {
		logger("$myself: ERROR: invalid value in 'theme_color' option. Defaulting to white theme.");
		$theme = $config{theme_color} = "white";
	}

	if($config{theme}->{$theme}) {
		$bgcolor = $config{theme}->{$theme}->{main_bg};
		$table_back_color = $config{theme}->{$theme}->{graph_bg};
		$title_back_color = $config{theme}->{$theme}->{title_bg};
		$title_fore_color = $config{theme}->{$theme}->{title_fg};
	}

	# Default option in 'Graph' list when 'All' is selected in 'Hostname' list.
	#
	# The following small JavaScript function is intended to avoid to select to view
	# accidentally (unless explicitly selected by the user) a huge amount of remote
	# images that will hang the browser for a while.
	$text_when_all = $config{multihost}->{default_option_when_all};
	my @match = grep { $config{graphs}{$_} eq $text_when_all } keys %{$config{graphs}};
	$value_when_all = $match[0] || "";
	if(!$value_when_all) {
		logger("$myself: ERROR: invalid value in 'default_option_when_all' option ('$text_when_all').");
		$value_when_all = "_system1";
	}
	$when_all_code = <<"EOF";
<!-- Default option code when 'All' is selected in 'Hostname' list -->
<script type="text/javascript">
   function auto_select() {
      var host = document.getElementById("hostname");
      var h = host.options[host.selectedIndex].text;
      var graph = document.getElementById("graph");
      var g = graph.options[graph.selectedIndex].text;
      if(h == "All" && g == "All graphs") {
         document.getElementById("graph").value = "$value_when_all";
      }
      return true;
   }
</script>
<!-- End Default option code when 'All' is selected in 'Hostname' list -->
EOF

	# Piwik tracking code
	if(lc($config{piwik_tracking}->{enabled} || "") eq "y") {
		$piwik_url = $config{piwik_tracking}->{url} || "";
		$piwik_sid = $config{piwik_tracking}->{sid} || "";
		$piwik_img = $config{piwik_tracking}->{img} || "";
		$piwik_code = <<"EOF";

<!-- Piwik -->
 <script type="text/javascript">
    var _paq = _paq || [];
    _paq.push(['trackPageView']);
    _paq.push(['enableLinkTracking']);
    (function() {
      var u=(("https:" == document.location.protocol) ? "https" : "http") + "$piwik_url";
      _paq.push(['setTrackerUrl', u+'piwik.php']);
      _paq.push(['setSiteId', $piwik_sid]);
      var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.type='text/javascript';
      g.defer=true; g.async=true; g.src=u+'piwik.js';
      s.parentNode.insertBefore(g,s);
    })();
 </script>
 <noscript>
   <p><img src="$piwik_img" style="border:0;" alt=""/></p>
 </noscript>
<!-- End Piwik Code -->
EOF
	}

	# force to only one trailing slash
	(my $base_url = $config{base_url}) =~ s/\/*$/\//;
	(my $base_cgi = $config{base_cgi}) =~ s/\/*$/\//;

	if(!open(OUT, "> $config{base_dir}/index.html")) {
		die "unable to create '${config{base_dir}}index.html': $!";
	}
	print(OUT <<EOF);
<!DOCTYPE html "-//W3C//DTD HTML 4.01 Final//EN">
<html>
 <head>
  <title>$config{title}</title>
  <link rel="shortcut icon" href="$base_url$config{favicon}">
 </head>
 <body bgcolor="$bgcolor" text="#888888" vlink="#888888" link="#888888">
  $piwik_code
  $when_all_code
  <center>
  <p>
  <br>
  <font face="Verdana, sans-serif">
  <table>
    <tr>
      <td>
        <a href="$config{logo_top_url}"><img src="$base_url$config{logo_top}" border="0"></a>
      </td>
    </tr>
    <tr>
      <td>
        <h2 align="right">v@{[VERSION]}</h2>
      </td>
    </tr>
  </table>
  <p>
  <form action="${base_cgi}monitorix.cgi" method="get">
    <table cellspacing="5" cellpadding="0" bgcolor="$table_back_color" border="1">
      <tr>
        <td bgcolor="$title_back_color">
          <font color="$title_fore_color">
<b>&nbsp;Hostname&nbsp;</b>
          </font>
       </td>
        <td bgcolor="$title_back_color">
          <font color="$title_fore_color">
<b>&nbsp;Graph&nbsp;</b>
          </font>
       </td>
     </tr>
      <tr>
EOF

	print(OUT "        <td bgcolor='$bgcolor'>\n");
	print(OUT "          <select name='mode' size='1' id='hostname' onchange='auto_select()'>\n");
	print(OUT "            <optgroup label='Local Host'>\n");
	print(OUT "            <option value='localhost'>localhost</option>\n");
	print(OUT "            </optgroup>\n");

	if(scalar(my @remotehost_list = split(',', $config{multihost}->{remotehost_list})) && lc($config{multihost}->{enabled} || "") eq "y") {
		print(OUT "            <optgroup label='Multihost'>\n");
		print(OUT "            <option value='multihost.all'>All</option>\n");
		for($n = 0; $n < scalar(@remotehost_list); $n++) {
			print(OUT "              <option value='multihost.$n'>" . trim($remotehost_list[$n]) . "</option>\n");
                              }
		print(OUT "            </optgroup>\n");

		if(lc($config{multihost}->{groups} || "") eq "y" ) {
			my @remotegroup_list = split(',', $config{multihost}->{remotegroup_list});
			print(OUT "            <optgroup label='Multihost-Groups'>\n");
			print(OUT "            <option value='multihost.group'>All Groups</option>\n");
			for($n = 0; $n < scalar(@remotegroup_list); $n++) {
				print(OUT "              <option value='multihost.group$n'>" . trim($remotegroup_list[$n]) . "</option>\n");
			}
			print(OUT "            </optgroup>\n");
		}
	}

	if(scalar(my @tal = split(',', $config{traffacct}->{list})) && lc($config{traffacct}->{enabled} || "") eq "y") {
		print(OUT "            <optgroup label='Traffic Accounting'>\n");
		print(OUT "              <option value='traffacct.all'>All</option>\n");
		for($n = 0; $n < scalar(@tal); $n++) {
			print(OUT "              <option value='traffacct.$n'>" . trim($tal[$n]) . "</option>\n");
                              }
		print(OUT "            </optgroup>\n");
	}
	print(OUT "          </select>\n");
	print(OUT "        </td>\n");



	print(OUT "        <td bgcolor='$bgcolor'>\n");
	print(OUT "          <select name='graph' size='1' id='graph'>\n");
	print(OUT "            <option value='all'>All graphs</option>\n");
	foreach (split(',', $config{graph_name})) {
		my $g = trim($_);
		if(lc($config{graph_enable}->{$g} || "") eq "y") {
			print(OUT "            <optgroup label='" . $config{graph_title}->{$g} . "'>\n");
			if($g eq "proc") {
				for($n = 0; $n < $config{proc}->{max}; $n++) {
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $config{graphs}->{$gname} . " " . $n . "</option>\n");
				}
				next;
			}
			if($g eq "gensens") {
				for($n = 0; $n < keys %{$config{gensens}->{list}}; $n++) {
					my $name = trim($config{gensens}->{title}->{$n});
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $name . "</option>\n");
				}
				next;
			}
			if($g eq "ipmi") {
				for($n = 0; $n < scalar(my @ipmi_list = split(',', $config{ipmi}->{list})); $n++) {
					my $name = trim($ipmi_list[$n]);
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $name . "</option>\n");
				}
				next;
			}
			if($g eq "ambsens") {
				for($n = 0; $n < scalar(my @ambsens_list = split(',', $config{ambsens}->{list})); $n++) {
					my $name = trim($ambsens_list[$n]);
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $name . "</option>\n");
				}
				next;
			}
			if($g eq "fs" || $g eq "process") {
				$n = 0;
				foreach my $k (sort keys %{$config{graphs}}) {
					if($k =~ m/$g/) {
						$gname = "_" . $g . ++$n;
						my $gname2 = "_" . $g . "0" . $n;
						if($config{graphs}->{$gname}) {
							print(OUT "              <option value='" . $gname2 ."'>" . $config{graphs}->{$gname} . "</option>\n");
						}
					}
				}
				next;
			}
			if($g eq "du") {
				for($n = 0; $n < scalar(my @du_list = split(',', $config{du}->{list})); $n++) {
					my $name = trim($du_list[$n]);
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $name . "</option>\n");
				}
				next;
			}
			if($g eq "net") {
				my $n2;
				for($n = 0; $n < scalar(my @nl = split(',', $config{net}->{list})); $n++) {
					$gname = "_" . $g;
					for($n2 = 1; $n2 <= 3; $n2++) {
						my $str = trim($nl[$n]) . " " . $config{graphs}->{$gname . $n2};
						print(OUT "              <option value='" . $gname . $n . $n2 . "'>" . $str . "</option>\n");
					}
				}
				next;
			}
			if($g eq "port") {
				for($n = 0; $n < $config{port}->{max} && $n < scalar(my @port_list = split(',', $config{port}->{list})); $n++) {
					my $num = trim($port_list[$n]);
					if(!$config{port}->{desc}->{$num}) {
						logger("$myself: port number '$num' listed but not defined.");
						next;
					}
					my $name = trim((split(',', $config{port}->{desc}->{$num}))[0]);
					my $pcon = trim((split(',', $config{port}->{desc}->{$num}))[2]);
					$gname = "_" . $g;
					foreach my $c (split('/', $pcon)) {
						$c = uc(trim($c));
						print(OUT "              <option value='" . $gname . $n . "'>" . $config{graphs}->{$gname} . " " . $num . " (" . $c . "-" . $name . ")" . "</option>\n");
					}
				}
				next;
			}
			if($g eq "fail2ban") {
				for($n = 0; $n < scalar(my @fail2ban_list = split(',', $config{fail2ban}->{list})); $n++) {
					my $name = trim($fail2ban_list[$n]);
					$gname = "_" . $g;
					print(OUT "              <option value='" . $gname . $n . "'>" . $name . "</option>\n");
				}
				next;
			}
			$n = 0;
			foreach my $k (sort keys %{$config{graphs}}) {
				if($k =~ m/$g/) {
					$gname = "_" . $g . ++$n;
					if($config{graphs}->{$gname}) {
						print(OUT "              <option value='" . $gname ."'>" . $config{graphs}->{$gname} . "</option>\n");
					}
				}
			}
			print(OUT "            </optgroup>\n");
		}
	}
	print(OUT "          </select>\n");
	print(OUT "        </td>\n");


	print(OUT <<EOF);
     </tr>
    </table>
    <p>
    <table cellspacing="5" cellpadding="0" bgcolor="$table_back_color" border="1">
     <tr>
EOF

	if(lc($config{enable_hourly_view} || "") eq "y" ) {
		print(OUT <<EOF);
        <td bgcolor="$title_back_color">
       	    <label>
		<input type="radio" name="when" value="1hour">
		<font color="$title_fore_color"><b>Hourly&nbsp;</b></font>
	    </label>
        </td>
EOF
	}

	print(OUT <<EOF);
        <td bgcolor="$title_back_color">
	    <label>
          	<input type="radio" checked name="when" value="1day">
            	<font color="$title_fore_color"><b>Daily&nbsp;</b></font>
	    </label>
        </td>
        <td bgcolor="$title_back_color">
       	    <label>
          	<input type="radio" name="when" value="1week">
            	<font color="$title_fore_color"><b>Weekly&nbsp;</b></font>
	    </label>
        </td>
        <td bgcolor="$title_back_color">
       	    <label>
          	<input type="radio" name="when" value="1month">
            	<font color="$title_fore_color"><b>Monthly&nbsp;</b></font>
	    </label>
        </td>
        <td bgcolor="$title_back_color">
       	    <label>
          	<input type="radio" name="when" value="1year">
            	<font color="$title_fore_color"><b>Yearly&nbsp;</b></font>
	    </label>
        </td>
      </tr>
EOF

	if($config{max_historic_years} > 1) {
		print(OUT "      <tr>\n");
	}
	for($n = 2; $n <= $config{max_historic_years}; $n++) {
		if($n > 2 && (($n - 2) % 4) == 0) {
			print(OUT "      </tr>\n");
			print(OUT "      <tr>\n");
		}
		print(OUT <<EOF);
        <td bgcolor="$title_back_color">
       	    <label>
          	<input type="radio" name="when" value="${n}year">
            	<font color="$title_fore_color"><b>$n Years&nbsp;</b></font>
	    </label>
        </td>
EOF
	}
	if($config{max_historic_years} > 1) {
		print(OUT "      </tr>\n");
	}

	print(OUT <<EOF);
    </table>
    <p>
    <input type="hidden" name="color" value="$theme">
    <input type="submit" value="    Ok    ">
  </form>
  </font>
  </center>
 </body>
</html>
EOF
	close(OUT);
}


# Main
# ----------------------------------------------------------------------------
getopts("c:p:d:vn", \%options) || usage();

if($options{v}) {
	print("Monitorix version " . VERSION . " (" . RELDATE . ")\n");
	print("by Jordi Sanfeliu <jordi\@fibranet.cat>\n");
	print("https://www.monitorix.org/\n\n");
	exit(0);
}
if(!$options{c}) {
	usage();
	exit(1);
}
$options{c} = (abs_path($options{c}) || $options{c}) unless $^V lt 5.6.2;
if(!stat($options{c})) {
	die "can't open file '$options{c}': $!";
}

# load main configuration file
my $conf = new Config::General(
	-ConfigFile => $options{c},
);
%config = $conf->getall;
$config{debug} = ();
$config{func_update} = ();

# get the current OS and kernel version and check its support
my $release;
($config{os}, undef, $release) = uname();
if(!($release =~ m/^(\d+)\.(\d+)/)) {
        die "FATAL: unable to get the kernel version.";
}
$config{kernel} = "$1.$2";

if(!grep {$_ eq $config{os}} @suppsys) {
	die "FATAL: your operating system ($config{os}) is not supported.";
}

if(grep {$_ eq $config{os}} ("FreeBSD", "OpenBSD", "NetBSD")) {
	$SIG{'CHLD'} = 'DEFAULT';
}	

$0 = sprintf("%s %s%s%s%s%s",
	$^V lt 5.6.2 ? "monitorix" : abs_path($0),
	$options{c} ? "-c $options{c}" : "",
	$options{p} ? " -p $options{p}" : "",
	$options{d} ? " -d $options{d}" : "",
	$options{v} ? " -v" : "",
	$options{n} ? " -n" : "");

daemonize() unless $options{n};
logger("Starting Monitorix version " . VERSION . " (pid $$).");
logger("Loaded main configuration file '$options{c}'.");

# save the pidfile
if($options{p}) {
	$options{p} = abs_path($options{p});
	open(OUT, "> $options{p}")
		|| die "could not open '$options{p}' for writing: $!";
	print(OUT "$$");
	close(OUT);
}

# change to a safety directory
unless(chdir("/tmp")) {
	die "can't chdir to /tmp: $!";
}

if($options{d}) {
	if($options{d} ne "none" && $options{d} ne "all") {
		@{$config{debug}} = split(',', $options{d});
		foreach my $t (@{$config{debug}}) {
			if(!grep {trim($_) eq $t} (split(',', $config{graph_name} . ", traffacct, emailreports"))) {
				die "Invalid debug key '$t'";
			}
		}
	}
	logger("Entering in debug mode.");
	logger("Changed process name to '$0'.");
}

# load additional configuration files
if($config{include_dir} && opendir(DIR, $config{include_dir})) {
	my @files = grep { !/^[.]/ } readdir(DIR);
	closedir(DIR);
	foreach my $c (sort @files) {
		next unless -f $config{include_dir} . "/$c";
		next unless $c =~ m/\.conf$/;
		logger("Loading extra configuration file '$config{include_dir}/$c'.");
		my $conf_inc = new Config::General(
			-ConfigFile => $config{include_dir} . "/$c",
		);
		my %config_inc = $conf_inc->getall;
		while(my ($key, $val) = each(%config_inc)) {
			if(ref($val) eq "HASH") {
				# two level options
				while(my ($key2, $val2) = each(%{$val})) {
					if(ref($val2) eq "HASH") {
						# three level options
						while(my ($key3, $val3) = each(%{$val2})) {
							$config{$key}->{$key2}->{$key3} = $val3;
							delete $config_inc{$key}->{$key2}->{$key3};
						}
						next;
					}
					$config{$key}->{$key2} = $val2;
					delete $config_inc{$key}->{$key2};
				}
				next;
			}
			# graph_name option is special
			if($key eq "graph_name") {
				$config{graph_name} .= ", $val";
				delete $config_inc{graph_name};
				next;
			}
			# one level options
			$config{$key} = $val;
			delete $config_inc{$key};
		}
	}
} else {
	logger("Can't read directory '$config{include_dir}'. $!")
		if $config{include_dir};
}

# make sure that some options are correctly defined
die "ERROR: 'base_dir' option does not exist.\n" if(!defined($config{base_dir}));
die "ERROR: 'base_lib' option does not exist.\n" if(!defined($config{base_lib}));
die "ERROR: 'base_url' option does not exist.\n" if(!defined($config{base_url}));
die "ERROR: 'base_cgi' option does not exist.\n" if(!defined($config{base_cgi}));

if(!$config{max_historic_years}) {
	logger("WARNING: the 'max_historic_years' option doesn't exist. Please consider upgrading your configuration file.");
	$config{max_historic_years} = 1;
}
if(!$config{net}->{max}) {
	logger("WARNING: the 'max' option in 'net.pm' doesn't exist. Please consider upgrading your configuration file.");
	$config{net}->{max} = 10;
}
if(!$config{global_zoom}) {
	logger("WARNING: the 'global_zoom' option is not valid or doesn't exist. Please consider upgrading your configuration file.");
	# it's set in 'monitorix.cgi'
}
if(!$config{image_format}) {
	logger("WARNING: the 'image_format' option is not valid or doesn't exist. Please consider upgrading your configuration file.");
	# it's set in 'monitorix.cgi'
}
if(!defined($config{logo_top_url})) {
	logger("WARNING: the 'logo_top_url' option doesn't exist. Please consider upgrading your configuration file.");
	$config{logo_top_url} = "https://www.monitorix.org/";
}
if(lc($config{httpd_builtin}->{enabled} || "") eq "y" && !$config{httpd_builtin}->{autocheck_responsiveness}) {
	logger("WARNING: the 'autocheck_responsiveness' option is not valid or doesn't exist. Please consider upgrading your configuration file.");
	$config{httpd_builtin}->{autocheck_responsiveness} = "y";
}
if(lc($config{multihost}->{enabled} || "") eq "y" && !$config{multihost}->{default_option_when_all}) {
	logger("WARNING: the 'default_option_when_all' option is not valid or doesn't exist. Please consider upgrading your configuration file.");
	$config{multihost}->{default_option_when_all} = "System load";
}
if(!$config{use_external_firewall}) {
	$config{use_external_firewall} = "n";
}

# save the path of the configuration file
if(open(OUT, "> " . $config{base_dir} . "/cgi/monitorix.conf.path")) {
	print(OUT "$options{c}\n");
	close(OUT);
} else {
	logger("WARNING: unable to create the file '$config{base_dir}/cgi/monitorix.conf.path'. $!");
}

if($config{os} eq "Linux") {
	# make sure that 'ip_default_table' option has a consistent value
	$config{ip_default_table} = "filter" if !$config{ip_default_table};

	# check 'iptables' version to include the new wait lock option '--wait'
	my $ipv = `iptables --version`;
	chomp($ipv);
	$ipv =~ s/^iptables v//;
	$ipv = sprintf("%03s.%03s.%03s", split('\.', $ipv));
	if($ipv gt "001.004.020") {       # 1.4.20
		$config{iptables_wait_lock} = " --wait ";
	} else {
		$config{iptables_wait_lock} = "";
	}
}

# make sure that there aren't residual Monitorix iptables rules
flush_accounting_rules(\%config, $options{d});

logger("Initializing graphs.");

# check for inconsistencies between enabled graphs and defined graphs
foreach my $g (sort keys %{$config{graph_enable}}) {
	if(lc($config{graph_enable}->{$g} || "") eq "y") {
		if(!grep {trim($_) eq $g} (split(',', $config{graph_name}))) {
			logger("WARNING: inconsitency between '<graph_enable>' and 'graph_name' options; '$g' doesn't exist.");
		}
	}
}

# initialize all enabled graphs
foreach (split(',', ($config{graph_name} || "") . ", traffacct")) {
	my $g = trim($_);
	my $e = "n";

	if($g eq "traffacct") {
		$e = lc($config{$g}->{enabled} || "");
	} else {
		$e = lc($config{graph_enable}->{$g} || "");
	}

	if($e eq "y") {
		my $init = $g . "_init";
		my $d = $g;

		undef($d) if(!grep {trim($_) eq $d} (@{$config{debug}}));
		if(defined($options{d}) && $options{d} eq "all") {
			$d = $g;
		}

		eval "use $g qw(" . $init . " " . $g . "_update)";
		if($@) {
			logger("WARNING: unable to load module '$g'. $@");
			next;
		}
		{
			no strict "refs";
			eval { &$init($g, \%config, $d); };
		}
		logger("WARNING: unexpected errors in function $init().") if($@);
	}
}

if(!scalar($config{func_update})) {
	logger("Nothing to do, exiting.");
	exit(0);
}

logger("Generating the 'index.html' file.");
create_index();

# start the HTTP built-in (if enabled)
if(lc($config{httpd_builtin}->{enabled} || "") eq "y") {
	logger("Setting owner/group and permission bits for the imgs/ directory.") if defined($options{d});
	my (undef, undef, $uid) = getpwnam($config{httpd_builtin}->{user});
	my (undef, undef, $gid) = getgrnam($config{httpd_builtin}->{group});
	chown($uid, $gid, $config{base_dir} . "/" . $config{imgs_dir});
	chmod(0755, $config{base_dir} . "/" . $config{imgs_dir});

	require HTTPServer;
	httpd_setup(\%config, $options{d});
	logger("Started HTTP built-in server (pid $config{httpd_pid}).") if (defined($config{httpd_pid}));
}

setpriority(0, 0, $config{priority} || 0);
logger("Ok, ready.");

# main loop
while(1) {

	select undef, undef, undef, 1.0;

	my ($sec, $min, $hour, $mday, $mon, undef, $wday) = localtime(time);

	# call to all enabled graphs on every minute
	if($sec == 0) {
		foreach my $f (@{$config{func_update}}) {
			my $update = $f . "_update";
			my $d = $f;
			logger("Calling $update()") unless !$options{d};

			undef($d) if(!grep {trim($_) eq $d} (@{$config{debug}}));
			if(defined($options{d}) && $options{d} eq "all") {
				$d = $f;
			}

			{
				no strict "refs";
				eval { &$update($f, \%config, $d); };
				if($@) {
					logger("$update(): $@");
				}
			}
		}

		# TRAFFACCT graph daily reports
		if(lc($config{traffacct}->{enabled} || "") eq "y") {
			my $d = "traffacct";
			undef($d) if(!grep {trim($_) eq $d} (@{$config{debug}}));

			# at 00:00h
			if($min == 0 && $hour == 0) {

				# collect traffic accounting every day
				eval { traffacct::traffacct_getcounters(\%config, $d); };
				if($@) {
					logger("traffacct::traffacct_getcounters(): $@");
				}

				# send reports every first day of a month
				if(lc($config{traffacct}->{reports}->{enabled} || "") eq "y") {
					if($mday == 1) {
						eval { traffacct::traffacct_sendreports(\%config, $d); };
						if($@) {
							logger("traffacct::traffacct_sendreports(): $@");
						}
					}
				}
			}
		}

		# Email Reports
		if(lc($config{emailreports}->{enabled} || "") eq "y") {
			my $emailreports = $config{emailreports};
			my $m = $emailreports->{minute} || 0;
			my $h = $emailreports->{hour} || 0;
			my $d = "emailreports";
			undef($d) if(!grep {trim($_) eq $d} (@{$config{debug}}));

			if($min == $m && $hour == $h) {

				eval "use emailreports qw(emailreports_send)";
				if($@) {
					logger("WARNING: unable to load module 'emailreports'. $@");
					next;
				}

				# daily
				if(lc($emailreports->{daily}->{enabled} || "") eq "y") {
					eval { emailreports::emailreports_send(\%config, "daily", "1day", $d); };
					if($@) {
						logger("emailreports::emailreports_send(): $@");
					}
				}

				# weekly (send reports on every Monday)
				if($wday == 1) {
					if(lc($emailreports->{weekly}->{enabled} || "") eq "y") {
						eval { emailreports::emailreports_send(\%config, "weekly", "1week", $d); };
						if($@) {
							logger("emailreports::emailreports_send(): $@");
						}
					}
				}

				# monthly (send reports every first day of each month)
				if($mday == 1) {
					if(lc($emailreports->{monthly}->{enabled} || "") eq "y") {
						eval { emailreports::emailreports_send(\%config, "monthly", "1month", $d); };
						if($@) {
							logger("emailreports::emailreports_send(): $@");
						}
					}
				}

				# yearly (send reports every first day of each year)
				if($mon == 0 && $mday == 1) {
					if(lc($emailreports->{yearly}->{enabled} || "") eq "y") {
						eval { emailreports::emailreports_send(\%config, "yearly", "1year", $d); };
						if($@) {
							logger("emailreports::emailreports_send(): $@");
						}
					}
				}
			}
		}

		# check if the HTTP built-in server is responsive
		if(lc($config{httpd_builtin}->{enabled} || "") eq "y") {
			if(lc($config{httpd_builtin}->{autocheck_responsiveness} || "") eq "y") {
				use LWP::UserAgent;
				my $pid = fork();
				if(!$pid) {
					my $url = "http://localhost:" . $config{httpd_builtin}->{port} . $config{base_url};
					my $ua = LWP::UserAgent->new(timeout => 30);
					my $response = $ua->request(HTTP::Request->new('GET', $url));
					if(!$response->is_success) {
						if($response->status_line ne "401 Access Denied") {
							logger("WARNING: HTTP built-in server not responding at '$url'.");
							exit(1);
						}
					}
					exit(0);
				}
				waitpid($pid, 0);
				# waitpid sets the child's status in $?
				if($? != 0) {
					# restart HTTP built-in server
					if(defined($config{httpd_pid})) {
						require HTTPServer;
						kill(15, $config{httpd_pid});
						kill(9, $config{httpd_pid});
						httpd_setup(\%config, $options{d});
						logger("Restarted HTTP built-in server (pid $config{httpd_pid}).") if defined($config{httpd_pid});
					}
				}
			}
		}
	}
	waitpid(-1, WNOHANG);
}