#!/usr/local/bin/php-cgi -q
<?php
/*
 * dhcpd_gather_stats.php
 *
 * part of pfSense (https://www.pfsense.org)
 * Copyright (c) 2013-2016 Rubicon Communications, LLC (Netgate)
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

require_once("config.inc");
require_once("interfaces.inc");
/* echo the rrd required syntax */
echo "N:";
$result = array();
$result['active'] = "NaN";
$result['static'] ="NaN";
$result['range'] ="NaN";

if (is_array($config['dhcpd'][$argv[1]])) {

	$leasesfile = "{$g['dhcpd_chroot_path']}/var/db/dhcpd.leases";
	$leases_contents = file($leasesfile);
	$dhcpif = $argv[1] ; 

	function remove_duplicate($array, $field) {
		foreach ($array as $sub) {
			$cmp[] = $sub[$field];
		}
		$unique = array_unique(array_reverse($cmp, true));
		foreach ($unique as $k => $rien) {
			$new[] = $array[$k];
		}
		return $new;
	}
	$awk = "/usr/bin/awk";
	/* this pattern sticks comments into a single array item */
	$cleanpattern = "'{ gsub(\"#.*\", \"\");} { gsub(\";\", \"\"); print;}'";
	/* We then split the leases file by } */
	$splitpattern = "'BEGIN { RS=\"}\";} {for (i=1; i<=NF; i++) printf \"%s \", \$i; printf \"}\\n\";}'";

	/* stuff the leases file in a proper format into a array by line */
	exec("/bin/cat {$leasesfile} | {$awk} {$cleanpattern} | {$awk} {$splitpattern}", $leases_content);
	$pools = array();
	$leases = array();
	$i = 0;
	$l = 0;
	$p = 0;

	// Put everything together again
	foreach ($leases_content as $lease) {
		/* split the line by space */
		$data = explode(" ", $lease);
		/* walk the fields */
		$f = 0;
		$fcount = count($data);
		/* with less than 20 fields there is nothing useful */
		if ($fcount < 20) {
			$i++;
			continue;
		}
		while ($f < $fcount) {
			switch ($data[$f]) {
				case "failover":
					$pools[$p]['name'] = trim($data[$f+2], '"');
					$pools[$p]['name'] = "{$pools[$p]['name']} (" . convert_friendly_interface_to_friendly_descr(substr($pools[$p]['name'], 5)) . ")";
					$pools[$p]['mystate'] = $data[$f+7];
					$pools[$p]['peerstate'] = $data[$f+14];
					$pools[$p]['mydate'] = $data[$f+10];
					$pools[$p]['mydate'] .= " " . $data[$f+11];
					$pools[$p]['peerdate'] = $data[$f+17];
					$pools[$p]['peerdate'] .= " " . $data[$f+18];
					$p++;
					$i++;
					continue 3;
				case "lease":
					$leases[$l]['ip'] = $data[$f+1];
					$leases[$l]['type'] = "dynamic";
					$f = $f+2;
					break;
				case "starts":
					$leases[$l]['start'] = $data[$f+2];
					$leases[$l]['start'] .= " " . $data[$f+3];
					$f = $f+3;
					break;
				case "ends":
					if ($data[$f+1] == "never") {
						// Quote from dhcpd.leases(5) man page:
						// If a lease will never expire, date is never instead of an actual date.
						$leases[$l]['end'] = gettext("Never");
						$f = $f+1;
					} else {
						$leases[$l]['end'] = $data[$f+2];
						$leases[$l]['end'] .= " " . $data[$f+3];
						$f = $f+3;
					}
					break;
				case "tstp":
					$f = $f+3;
					break;
				case "tsfp":
					$f = $f+3;
					break;
				case "atsfp":
					$f = $f+3;
					break;
				case "cltt":
					$f = $f+3;
					break;
				case "binding":
					switch ($data[$f+2]) {
						case "active":
							$leases[$l]['act'] = "active";
							break;
						case "free":
							$leases[$l]['act'] = "expired";
							$leases[$l]['online'] = "offline";
							break;
						case "backup":
							$leases[$l]['act'] = "reserved";
							$leases[$l]['online'] = "offline";
							break;
					}
					$f = $f+1;
					break;
				case "next":
					/* skip the next binding statement */
					$f = $f+3;
					break;
				case "rewind":
					/* skip the rewind binding statement */
					$f = $f+3;
					break;
				case "uid":
					$f = $f+1;
					break;
			}
			$f++;
		}
		$l++;
		$i++;
		/* slowly chisel away at the source array */
		array_shift($leases_content);
	}
	/* remove the old array */
	unset($lease_content);

	/* remove duplicate items by mac address */
	if (count($leases) > 0) {
		$leases = remove_duplicate($leases, "ip");
	}

	if (count($pools) > 0) {
		$pools = remove_duplicate($pools, "name");
		asort($pools);
	}

	foreach ($config['interfaces'] as $ifname => $ifarr) {
		if (is_array($config['dhcpd'][$ifname]) &&
			is_array($config['dhcpd'][$ifname]['staticmap'])) {
			$staticmap_array_index = 0;
			foreach ($config['dhcpd'][$ifname]['staticmap'] as $static) {
				$slease = array();
				$slease['ip'] = $static['ipaddr'];
				$slease['act'] = "static";
				$slease['staticmap_array_index'] = $staticmap_array_index;
				$leases[] = $slease;
				$staticmap_array_index++;
			}
		}
	}
	$ifcfgip = get_interface_ip($dhcpif);
	$ifcfgsn = get_interface_subnet($dhcpif);
	$subnet_start = gen_subnetv4($ifcfgip, $ifcfgsn);
	$subnet_end = gen_subnetv4_max($ifcfgip, $ifcfgsn);

	$result['range'] = ip_range_size_v4(
	    $config['dhcpd'][$dhcpif]['range']['from'],
	    $config['dhcpd'][$dhcpif]['range']['to']);
	
	foreach ($leases as $data) {
		if ($data['act'] != "active" && $data['act'] != "static" && $_GET['all'] != 1)
			continue;
		if ($data['act'] != "static") {
			if (is_inrange_v4($data['ip'], $config['dhcpd'][$dhcpif]['range']['from'], $config['dhcpd'][$dhcpif]['range']['to'])) {
					$result['active'] = $result['active'] + 1;
			}
		}
		else {
			if (is_inrange_v4($data['ip'], $subnet_start, $subnet_end)) {
				$result['static'] = $result['static'] + 1;
			}
		}
	}
}
echo $result['active'].":".$result['static'].":".$result['range'] ;