<?php

/* $Id$ */
/*
	tinydns.inc
	Copyright (C) 2006, 2007, 2008 Scott Ullrich
	Parts Copyright (C) 2007 Goffredo Andreone
	part of pfSense
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:

	1. Redistributions of source code must retain the above copyright notice,
	   this list of conditions and the following disclaimer.

	2. 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.

	THIS SOFTWARE IS PROVIDED ``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
	AUTHOR 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.
*/

require_once("filter.inc");

function tinydns_custom_php_install_command() {
	global $g, $config;
	conf_mount_rw();
	$fd = fopen("/usr/local/etc/rc.d/svscan.sh", "w");
	if(!$fd) {
		log_error("Could not open /usr/local/etc/rc.d/svscan.sh for writing.");
		return;
	}
	$ipaddress = $config['installedpackages']['tinydns']['config'][0]['ipaddress'];

	$minsegment = "10240";
	$maxfilesize = "10240";
	$maxsegment  = "20480";
	$maxfd = "100";
	$maxchild = "40";

	if($config['installedpackages']['tinydns']['config'][0]['minsegment'])
		$minsegment = $config['installedpackages']['tinydns']['config'][0]['minsegment'];

	if($config['installedpackages']['tinydns']['config'][0]['maxfilesize'])
		$maxfilesize = $config['installedpackages']['tinydns']['config'][0]['maxfilesize'];

	if($config['installedpackages']['tinydns']['config'][0]['maxsegment'])
		$maxsegment = $config['installedpackages']['tinydns']['config'][0]['maxsegment'];

	if($config['installedpackages']['tinydns']['config'][0]['maxfd'])
		$maxfd = $config['installedpackages']['tinydns']['config'][0]['maxfd'];

	if($config['installedpackages']['tinydns']['config'][0]['maxchild'])
		$maxchild = $config['installedpackages']['tinydns']['config'][0]['maxchild'];

	if($config['installedpackages']['tinydns']['config'][0]['refreshinterval'])
		$refreshinterval = $config['installedpackages']['tinydns']['config'][0]['refreshinterval'];

	$svscan = <<<EOD
#!/bin/sh

# PROVIDE: svscan
# REQUIRE: LOGIN
# KEYWORD: FreeBSD

. /etc/rc.subr

name="svscan"
rcvar=`set_rcvar`
command="/usr/local/bin/svscan"
svscan_enable=\${svscan_enable-"YES"}
svscan_servicedir=\${svscan_servicedir-"/service"}

start_cmd="svscan_start"
stop_postcmd="svscan_stop_post"

load_rc_config \$name

required_dirs="\${svscan_servicedir}"

svscan_start () {
        echo "Starting svscan."
        /usr/bin/env \
        PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin \
        /usr/sbin/daemon -f /bin/sh -c "\$command \$svscan_servicedir 2>&1 | /usr/local/bin/readproctitle service errors: ................................................................................................................................................................................................................................................................................................................................................................................................................ &" > /dev/null
        minicron {$refreshinterval} /var/run/ping_hosts.pid "/etc/ping_hosts.sh; cd /etc/tinydns/root && /usr/local/bin/tinydns-data"
}

svscan_stop_post () {
        echo "Stopping svscan."
        find -L "\$svscan_servicedir" -mindepth 1 -maxdepth 2 -type d \( \! -path "\$svscan_servicedir/*/*" -or -name 'log' \) -print0 | xargs -0 /usr/local/bin/svc -dx
        PIDTOKILL=`cat /var/run/ping_hosts.pid`
        kill $PIDTOKILL
}

run_rc_command "\$1"

EOD;

	fwrite($fd, $svscan);
	fclose($fd);
	conf_mount_ro();
	filter_configure();

	tinydns_custom_php_changeip_command();
	
	exec("/usr/local/etc/rc.d/svscan.sh start");
}

function tinydns_custom_php_deinstall_command() {
	global $g, $config;
	conf_mount_rw();
	/* destroy all daemontools items */
	exec("/usr/sbin/pw groupdel Gtinydns");
	exec("/usr/sbin/pw groupdel Gdnscache");
	exec("/usr/sbin/pw groupdel Gdnslog");
	exec("/usr/sbin/pw userdel Gtinydns");
	exec("/usr/sbin/pw userdel Gdnscache");
	exec("/usr/sbin/pw userdel Gdnslog");
	exec("rm /usr/local/www/*tinydns*");
	exec("rm /usr/local/pkg/*tinydns*");
	exec("rm /usr/local/pkg/pf/*tinydns*");
	conf_mount_ro();
	filter_configure();
}

function tinydns_custom_php_changeip_command() {
	global $g, $config;
	conf_mount_rw();

	$ip = $config['interfaces']['lan']['ipaddr'];
	$ipmask = $config['interfaces']['lan']['subnet'];
	$arr = tinydns_get_ip_subnet_arpa($ip, $ipmask);
	$dnscacheip = $ip;
	$dnsuserip = $arr[0];

	/* For now force $dnsserverip to to 127.0.0.1 unless a separate IP is specified */
	$localhost = "127.0.0.1";
	$dnsserverip = $localhost;
	if($config['installedpackages']['tinydns']['config'][0]['ipaddress'] != $localhost AND $config['installedpackages']['tinydns']['config'][0]['ipaddress'] != "")
		$dnsserverip = $config['installedpackages']['tinydns']['config'][0]['ipaddress'];
	if($config['installedpackages']['tinydns']['config'][0]['regdhcpstatic'] OR $config['installedpackages']['tinydns']['config'][0]['regdhcp']) 
		$dnsserverip = $localhost;
	$config['installedpackages']['tinydns']['config'][0]['ipaddress'] = $dnsserverip;

	$updatecron = $config['installedpackages']['tinydns']['config'][0]['updatecron'];

	/* setup daemon tools service area */
	if(!is_dir("/service"))	
		exec("/bin/mkdir /service");

	exec("/usr/sbin/pw useradd Gtinydns");
	exec("/usr/sbin/pw useradd Gdnslog");
	exec("/usr/sbin/pw useradd Gdnscache");

	exec("/usr/local/bin/tinydns-conf Gtinydns Gdnslog /etc/tinydns {$dnsserverip}");
	exec("/bin/ln -s /etc/tinydns /service/");

	exec("echo {$dnsserverip} > /etc/tinydns/env/IP");
	exec("/usr/bin/killall -9 tinydns");

	if($config['installedpackages']['tinydns']['config'][0]['enableforwarding']) {
		if(!is_dir("/service/dnscache")) {
				exec("/usr/sbin/pw useradd Gdnscache");
				exec("/usr/local/bin/dnscache-conf Gdnscache Gdnslog /etc/dnscache {$dnscacheip}");
				exec("/bin/ln -s /etc/dnscache /service/");
				exec("/bin/cp /var/etc/resolv.conf /var/etc/resolv.conf.original");
				exec("/bin/cp /var/etc/resolv.conf /var/etc/resolv.conf.dnscache");
		}
		exec("echo {$dnscacheip} > /etc/dnscache/env/IP");
		tinydns_dnscache_forwarding_servers();
		exec("touch /etc/dnscache/root/ip/{$dnsuserip}");
		tinydns_create_soa_domain_list($dnsserverip);
		exec("echo domain {$config['system']['domain']} > /var/etc/resolv.conf");
		exec("echo nameserver {$dnscacheip} >> /var/etc/resolv.conf");
		exec("/usr/bin/killall -9 dnscache");
	} else {
		if(file_exists("/var/etc/resolv.conf.original"))
			exec("/bin/cp /var/etc/resolv.conf.original /var/etc/resolv.conf");
		if(is_dir("/etc/dnscache")) {
			dnscache_use_root_servers();
			exec("/usr/bin/killall -9 dnscache");
		}
	}
	conf_mount_ro();
	filter_configure();
}

function tinydns_get_record_status($record, $pingthreshold = "", $wanpingthreshold = "") {
	global $g, $config;
	if(file_exists("/var/db/pingstatus/{$record}")) {
		$status = "";
		$status = file_get_contents("/var/db/pingstatus/{$record}");
		if(stristr($status,"DOWN"))
			return "DOWN";
	}
	if($pingthreshold) {
		$current_ms = "";
		if(file_exists("var/db/pingmsstatus/$record"))
			$current_ms = file_get_contents("/var/db/pingmsstatus/$record");
		if($pingthreshold > $current_ms)
			return "DOWN";
	}
	if($wanpingthreshold) {
		$current_avg = "";
		if(file_exists("/var/db/wanaverage"))
			$current_avg = file_get_contents("/var/db/wanaverage");
		if($wanpingthreshold > $current_avg)
			return "DOWN";
	}
	return "UP";
}

function tinydns_get_backup_record($record) {
	global $g, $config;
	if($config['installedpackages']['tinydnsdomains']) {
		foreach($config['installedpackages']['tinydnsdomains']['config'] as $domain) {
			if($domain['ipaddress'] == $record) {
				/* if no failover host exists, simply return original record */
				if(!$domain['row'])
					return $record;
				foreach($domain['row'] as $row) {
					$status = tinydns_get_record_status($row['failoverip']);
					if($status == "UP")
						return $row['failoverip'];
				}
			}
		}
	}
	return $record;
}

function tinydns_setup_ping_items() {
	global $g, $config;
	if(!$config['installedpackages']['tinydnsdomains'])
		return;
	$wanif = get_real_wan_interface();
	$ip = find_interface_ip($wanif);
	conf_mount_rw();
	$processed = array();
	/* XXX: make this work with other packages */
	$fd = fopen("/var/db/pkgpinghosts", "w");
	if(!$fd) {
		log_error("Could not open /var/db/pkgpinghosts for writing.");
		return;
	}
	config_lock();
	/*   write out each ip address so ping_hosts.sh can begin monitoring ip
	 *   status and create a database of the status information that we can use.
	 */
	foreach($config['installedpackages']['tinydnsdomains']['config'] as $domain) {
		if(!in_array($domain['ipaddress'], $processed)) {
			fwrite($fd, $ip . "|" . $domain['ipaddress'] . "|1|/usr/local/pkg/tinydns_down.php|/usr/local/pkg/tinydns_up.php\n");
			$processed[] = $domain['ipaddress'];
		}
		if($domain['monitorip'] <> "")
			$monitorip = $domain['monitorip'];
		if($domain['row']) {
			foreach($domain['row'] as $row) {
				if($row['pingthreshold'])
					$pingthreshold = $row['pingthreshold'];
				else
					$row['pingthreshold'] = "";
				if($row['monitorip']) {
					if(!in_array($row['monitorip'], $processed)) {
						fwrite($fd, $ip . "|" . $row['monitorip'] . "|1|/usr/local/pkg/tinydns_down.php|/usr/local/pkg/tinydns_up.php|{$pingthreshold}\n");
						$processed[] = $row['monitorip'];
					}
				} else {
					if(!in_array($monitorip, $processed)) {
						fwrite($fd, $ip . "|" . $monitorip . "|1|/usr/local/pkg/tinydns_down.php|/usr/local/pkg/tinydns_up.php|{$pingthreshold}\n");
						$processed[] = $monitorip;
					}
				}
			}
		}
		if($domain['monitorip']) {
			if(!in_array($domain['monitorip'], $processed)) {
				fwrite($fd, $ip . "|" . $domain['monitorip'] . "|1|/usr/local/pkg/tinydns_down.php|/usr/local/pkg/tinydns_up.php|{$pingthreshold}\n");
				$processed[] = $domain['monitorip'];
			}
		} else {
			if(!in_array($row['failoverip'], $processed)) {
				fwrite($fd, $ip . "|" . $row['failoverip'] . "|1|/usr/local/pkg/tinydns_down.php|/usr/local/pkg/tinydns_up.php|{$pingthreshold}\n");
				$processed[] = $row['failoverip'];
			}
		}
	}
	fclose($fd);
	config_unlock();
	conf_mount_ro();
}

function tinydns_create_zone_file() {
	global $g, $config;
	conf_mount_rw();
	if(file_exists("/tmp/config.cache"))
		unlink("/tmp/config.cache");
	parse_config(true);
	config_lock();
	if(file_exists("/service/tinydns/root/data"))
		exec("rm -f /service/tinydns/root/data");
	if(!is_dir("/service/tinydns/root"))
		return;
	$fd = fopen("/service/tinydns/root/data", "w");
	if(!$fd) {
		log_error("Could not open /service/tinydns/root/data for writing.");
		return;
	}
	
	/* For now do not allow registration of 'local' DNS data if tinyDNS not bound to 127.0.0.1 */
	if($config['installedpackages']['tinydns']['config'][0]['ipaddress'] == "127.0.0.1") {
		/* Load the root servers if Forwarding is enabled  */
		/* Register LAN IP and SOA Forward and Reverse DNS recors in TinyDNS Server*/
		if($config['installedpackages']['tinydns']['config'][0]['enableforwarding']) {
			$forwardingservers = tinydns_register_root_servers();
			if($forwardingservers) 
				fwrite($fd, $forwardingservers);
			if($config['system']['hostname']['domain']) {
				$dhcpdhostname = $config['system']['hostname'];		
				if($config['dhcpd']['lan'])
					$dhcpddomain = $config['system']['domain'];
				$dhcpdlanip = $config['interfaces']['lan']['ipaddr'];		
				$dhcpdipmask = $config['interfaces']['lan']['subnet'];		
				$dhcpdfqdn = "{$dhcpdhostname}.{$dhcpddomain}";
				tinydns_complete_soa_record($fd, $dhcpdlanip, $dhcpdipmask, $dhcpdhostname, $dhcpddomain);
			}
		}
	
		/* Register Static IPs */
        if($config['installedpackages']['tinydns']['config'][0]['regdhcpstatic']) {
                foreach($config['dhcpd'] as $zone_key => $zone ) {
                        $dhcpdhostname = $config['system']['hostname'];
                        if ($zone['ddnsdomain']) 
                                $dhcpddomain = $zone['ddnsdomain'];
                        else
                                $dhcpddomain = $config['system']['domain'];
                        $dhcpdlanip = $config['interfaces'][$zone_key]['ipaddr'];
                        $dhcpdipmask = $config['interfaces'][$zone_key]['subnet'];
                        $dhcpdfqdn = "{$dhcpdhostname}.{$dhcpddomain}";
                        tinydns_complete_soa_record($fd, $dhcpdlanip, $dhcpdipmask, $dhcpdhostname, $dhcpddomain);
       
                        if(is_array($zone['staticmap'])) {
                                foreach($zone['staticmap'] as $dhcpdstatic) {
                                        $dhcpdhostname = $dhcpdstatic['hostname'];
                                        $dhcpdfqdn = "{$dhcpdhostname}.{$dhcpddomain}";
                                        $dhcpdlanip = $dhcpdstatic['ipaddr'];
                                        $dhcpda = "={$dhcpdfqdn}:{$dhcpdlanip}";
                                        if($dhcpdhostname)
                                                fwrite($fd, $dhcpda . "\n");
                                }
                        }
                }
        }
	
		/* Register Dynamic IPs */
		if($config['installedpackages']['tinydns']['config'][0]['regdhcp']) {
			$leasesfile = "{$g['dhcpd_chroot_path']}/var/db/dhcpd.leases";
			$fl = fopen($leasesfile, "r");
			if(!$fl) {
				log_error("Could not open {$leasesfile} for reading.");
				return;
			}
			tinydns_add_active_leases($fl,$fd, $dhcpddomain);
		}
	}
		
	if($config['installedpackages']['tinydnsdomains']) {
		for($x=0; $x< count($config['installedpackages']['tinydnsdomains']['config']); $x++) {
			$domain = $config['installedpackages']['tinydnsdomains']['config'][$x];
			$record_data = "";
			$hostname = $domain['hostname'];
			$ipaddress = $domain['ipaddress'];
			$ttl = $domain['ttl'];
			/*   check record status, if it is down request
			 *   backup server if defined.
			 */
			if($domain['monitorip'])
				$monitorip = $domain['monitorip'];
			if($monitorip) {
				$status = tinydns_get_record_status($monitorip);
				if($status == "DOWN") {
					if($debug)
						log_error("$ipaddress monitor ip $monitorip is offline.");
					$ipaddress = tinydns_get_backup_record($ipaddress);
					if($debug)
						log_error("tinydns_get_backup_record returned $ipaddress ");
				}
			}
			$record_data = tinydns_get_rowline_data($ipaddress, $domain['recordtype'], $ttl, $hostname, $domain['rdns']);
			if($record_data) 
				fwrite($fd, $record_data . "\n");
			/* process load balanced items */
			if($domain['row']) {
				foreach($domain['row'] as $row) {
					if($row['loadbalance']) {
						if($row['pingthreshold'])
							$pingthreshold = $row['pingthreshold'];
						else
							$pingthreshold = "";
						if($row['wanpingthreshold'])
							$wanpingthreshold =	$row['wanpingthreshold'];
						else
							$wanpingthreshold = "";
						$status = tinydns_get_record_status($row['failoverip'], $pingthreshold, $wanpingthreshold);
						if($status == "DOWN") {
							$record_data = tinydns_get_rowline_data($row['failoverip'], $domain['recordtype'], $ttl, $hostname, "");
							fwrite($fd, $record_data . "\n");
						}
					}
				}
			}
		}
	}
	fclose($fd);
	/* tell tinydns to reload zone file */
	exec("cd /service/tinydns/root && /usr/local/bin/tinydns-data");
	config_unlock();
	conf_mount_ro();
}

function tinydns_sync_on_changes() {
	global $g, $config;
	$synconchanges = $config['installedpackages']['tinydns']['config'][0]['synconchanges'];	
	if(!$synconchanges) 
		return;
	$sync_hosts = $config['installedpackages']['tinydnssync']['config'];
	foreach($sync_hosts as $sh) {
		$sync_to_ip = $sh['ipaddress'];
		$password   = $sh['password'];
		if($password and $sync_to_ip) 
			tinydns_do_xmlrpc_sync($sync_to_ip, $password);
	}	
}

function tinydns_do_xmlrpc_sync($sync_to_ip, $password) {
	global $config, $g;

	if(!$password)
		return;

	if(!$sync_to_ip)
		return;

	$xmlrpc_sync_neighbor = $sync_to_ip;
    if($config['system']['webgui']['protocol'] != "") {
		$synchronizetoip = $config['system']['webgui']['protocol'];
		$synchronizetoip .= "://";
    }
    $port = $config['system']['webgui']['port'];
    /* if port is empty lets rely on the protocol selection */
    if($port == "") {
		if($config['system']['webgui']['protocol'] == "http") 
			$port = "80";
		else 
			$port = "443";
    }
	$synchronizetoip .= $sync_to_ip;

	/* xml will hold the sections to sync */
	$xml = array();
	$xml['tinydnsdomains'] = $config['installedpackages']['tinydnsdomains'];

	/* assemble xmlrpc payload */
	$params = array(
		XML_RPC_encode($password),
		XML_RPC_encode($xml)
	);

	/* set a few variables needed for sync code borrowed from filter.inc */
	$url = $synchronizetoip;
	log_error("Beginning TinyDNS XMLRPC sync to {$url}:{$port}.");
	$method = 'pfsense.merge_installedpackages_section_xmlrpc';
	$msg = new XML_RPC_Message($method, $params);
	$cli = new XML_RPC_Client('/xmlrpc.php', $url, $port);
	$cli->setCredentials('admin', $password);
	if($g['debug'])
		$cli->setDebug(1);
	/* send our XMLRPC message and timeout after 250 seconds */
	$resp = $cli->send($msg, "250");
	if(!$resp) {
		$error = "A communications error occured while attempting tinydns XMLRPC sync with {$url}:{$port}.";
		log_error($error);
		file_notice("sync_settings", $error, "tinydns Settings Sync", "");
	} elseif($resp->faultCode()) {
		$cli->setDebug(1);
		$resp = $cli->send($msg, "250");
		$error = "An error code was received while attempting tinydns XMLRPC sync with {$url}:{$port} - Code " . $resp->faultCode() . ": " . $resp->faultString();
		log_error($error);
		file_notice("sync_settings", $error, "tinydns Settings Sync", "");
	} else {
		log_error("tinydns XMLRPC sync successfully completed with {$url}:{$port}.");
	}
	
	/* tell tinydns to reload our settings on the destionation sync host. */
	$method = 'pfsense.exec_php';
	$execcmd  = "require('/usr/local/pkg/tinydns.inc');\n";
	$execcmd .= "tinydns_custom_php_changeip_command();\n";
	$execcmd .= "tinydns_custom_php_install_command();\n";
	$execcmd .= "tinydns_create_zone_file();\n";
	$execcmd .= "tinydns_setup_ping_items();\n";
	
	/* assemble xmlrpc payload */
	$params = array(
		XML_RPC_encode($password),
		XML_RPC_encode($execcmd)
	);

	$msg = new XML_RPC_Message($method, $params);
	$cli = new XML_RPC_Client('/xmlrpc.php', $url, $port);
	$cli->setCredentials('admin', $password);
	$resp = $cli->send($msg, "250");
	if(!$resp) {
		$error = "A communications error occured while attempting tinydns XMLRPC sync with {$url}:{$port} (pfsense.exec_php).";
		log_error($error);
		file_notice("sync_settings", $error, "tinydns Settings Sync", "");
	} elseif($resp->faultCode()) {
		$cli->setDebug(1);
		$resp = $cli->send($msg, "250");
		$error = "An error code was received while attempting tinydns XMLRPC sync with {$url}:{$port} - Code " . $resp->faultCode() . ": " . $resp->faultString();
		log_error($error);
		file_notice("sync_settings", $error, "tinydns Settings Sync", "");
	} else {
		log_error("tinydns XMLRPC sync successfully completed with {$url}:{$port} (pfsense.exec_php).");
	}
	
	log_error("[tinydns] tinydns_xmlrpc_sync.php is ending.");
}

/* formats data as a tinydns data row item */
/* A full description of the data format is available at 'man tinydns-data' */
function tinydns_get_rowline_data($recordip, $recordtype, $ttl, $hostname, $rdns) {
		if($ttl)
			$ttl_string = ":{$ttl}";
		else
			$ttl_string = "";
		switch ($recordtype) {
			case "SOA":
				$record_data = ".{$hostname}::{$recordip}{$ttl_string}";
				break;
			case "NS":
				$record_data = "&{$hostname}:{$recordip}{$ttl_string}";
				break;
			case "MX":
				$record_data = "@{$hostname}:{$recordip}::{$ttl_string}";
				break;
			case "PTR":
				/* "^" creates "PTR" record only to allow reverse DNS */
				$record_data = "^{$hostname}:{$recordip}{$ttl_string}";
				break;
			case "A":
				/* "=" creates both "A" and "PTR" records to allow both forward and reverse DNS */
				if($rdns)
					$record_data = "={$hostname}:{$recordip}{$ttl_string}";
				else
				/* "+" creates "A" records only to allow forward DNS */
					$record_data = "+{$hostname}:{$recordip}{$ttl_string}";					
				break;
			case "CNAME":
				$record_data = "C{$hostname}:{$recordip}{$ttl_string}";
				break;
			case "TXT":
				/* "'" creates "TXT" record that can be used for SPF */
				$record_data = "'{$hostname}:{$recordip}{$ttl_string}";
				break;
		}
		return $record_data;
}

/* Returns the last IP byte and the Trimmed IP*/
function tinydns_get_lastip_byte($ipsub) {
	$len= strlen($ipsub); 	
	$pos = strrpos($ipsub, ".");
	$last_byte = "";
	if ($pos === false) { 
			$last_byte = $ipsub; 
			return array ($last_byte,$ipsub); 
	} 
	$last_byte = substr($ipsub,$pos + 1);
	$ipsub = substr($ipsub,0,$pos);
	return array ($last_byte,$ipsub);
}

/* in-add.arpa IP calculated from D.C.B.A and Mask to A.B.C.D.in-addr.arpa */
/* subnet IP calculated from A.B.C.D and Mask */
function tinydns_get_ip_subnet_arpa($ip, $ipmask) {
	$ipsub = $ip;	
	$arpaip = "";	
	$array = tinydns_get_lastip_byte($ipsub);
	$a = $array[0];
	$ipsub = $array[1];
	$array = tinydns_get_lastip_byte($ipsub);
	$b = $array[0];
	$ipsub = $array[1];
	$array = tinydns_get_lastip_byte($ipsub);
	$c = $array[0];
	$ipsub = $array[1];
	$array = tinydns_get_lastip_byte($ipsub);
	$d = $array[0];
	$ipsub = $array[1];
	switch ($ipmask) {
		case ($ipmask <= 32 AND $ipmask > 24):
			$s = 32 - $ipmask;
			$a >> $s;
			$arpaip = "{$a}.{$b}.{$c}.{$d}.in-addr.arpa";
			$subnet = "{$d}.{$c}.{$b}.{$a}";
			break;
		case ($ipmask <= 24 AND $ipmask > 16):
			$s = 24 - $ipmask;
			$b >> $s;
			$arpaip = "{$b}.{$c}.{$d}.in-addr.arpa";
			$subnet = "{$d}.{$c}.{$b}";
			break;
		case ($ipmask <= 16 AND $ipmask > 8):
			$s = 16 - $ipmask;
			$c >> $s;
			$arpaip = "{$c}.{$d}.in-addr.arpa";
			$subnet = "{$d}.{$c}";
			break;
		case ($ipmask <= 8 AND $ipmask > 0):
			$s = 8 - $ipmask;
			$d >> $s;
			$arpaip = "{$d}.in-addr.arpa";
			$subnet = "{$d}";
			break;
		}
	return 	array($subnet,$arpaip);
}

/* Create a Forward and a Reverse DNS (SOA, A, PTR) records for Fully Qualififed Domain Name*/
function tinydns_complete_soa_record($fd, $ip, $ipmask, $nsname, $domain) {
	$fqdn = "{$nsname}.{$domain}";
	$rip = tinydns_get_ip_subnet_arpa($ip, $ipmask);
	$soa = ".{$domain}::{$fqdn}";
	$rsoa = ".{$rip[1]}::{$fqdn}";
	$a = "={$fqdn}:{$ip}";
	if($fqdn)
		fwrite($fd, $soa . "\n");
	if($rip) 
		fwrite($fd, $rsoa . "\n");
	if($nsname) 
		fwrite($fd, $a . "\n");
}

/* Search for active leases in the dhcpd.leases file and add them to tinyDNS */
/* Currently it will add duplicate leases that are ignored by thee tinyDNS server*/
/* Should duplicate leases be purged by DCHCP server in a remove stale records operation? */
function tinydns_add_active_leases($fl,$fd, $leasedomain) {
	$i = 0;
	$lip = strlen("lease") + 1;
	$lis = strlen("binding state active");
	$lic = strlen("client-hostname");
	$leaseip = "";
	$leasestatus = "";
	$leasehostname = "";
	while (!feof($fl)) {
		$leases = fgets($fl, 4096);
		$discard = ($leases[0] == "#") OR ($leases[0] == "\n"); 
		if(!$discard) {
			if($leaseip == "") {
				if ($leaseip = strstr($leases,"lease")) {
					$leaseip = substr($leaseip,$lip,strpos($leases,"{") - $lip - 1);
				}
			}
			elseif($leasestatus == FALSE) {
				if (stristr($leases,"binding state active")) {
					$leasestatus = TRUE;
				}
			}
			elseif($leasestatus == TRUE AND $leasehostname == "") {
				if($leasehostname = stristr($leases,"client-hostname")) {
					$qstrt = strpos($leasehostname,'"') + 1;
					$qlen  = strrpos($leasehostname,'"') - $qstrt;
					$leasehostname = substr($leasehostname,$qstrt,$qlen);
				}
			}
			if($leases[0] == "}") {
				$leasefqdn = "{$leasehostname}.{$leasedomain}";
				$leasea = "={$leasefqdn}:{$leaseip}";
				if($leasehostname AND $leasestatus)fwrite($fd, $leasea . "\n");
				$leaseip = "";
				$leasehostname = "";
				$leasestatus = FALSE;
			}
			$i = $i + 1;
		}
	}
	fclose($fl);
	$leaselines = $i;
}

function tinydns_get_dns_record_type($tinydnsrecord) {
	$rtype = "";
	$rtype2 = "";
	$rdns = "";
	switch ($tinydnsrecord) {
		case($tinydnsrecord[0] == "."):
			$rtype = "SOA";
			$rtype2 = "NS";
			break;
		case($tinydnsrecord[0] == "="):
			$rtype = "A";
			$rtype2 = "PTR";
			$rdns = "on";
			break;
		case($tinydnsrecord[0] == "+"):
			$rtype = "A";
			break;
		case($tinydnsrecord[0] == "@"):
			$rtype = "MX";
			break;
		case($tinydnsrecord[0] == "^"):
			$rtype = "PTR";
			$rdns = "on";
			break;
		case($tinydnsrecord[0] == "&"):
			$rtype = "NS";
			break;
		case($tinydnsrecord[0] == "'"):
			$rtype = "TXT";
			break;
		case($tinydnsrecord[0] == "C"):
			$rtype = "CNAME";
			break;
		case($tinydnsrecord[0] == "Z"):
			$rtype = "SOA";
			break;
		default:
			$rtype = "";
	}
	return array ($rtype, $rtype2, $rdns);
}

/* This function will be replaced by an auto detect DNS cache servers routine */
/* At the moment there is no tagging of DNSroute to a WAN port. It needs to be added  */
function tinydns_dnscache_forwarding_servers() {
	$fr = fopen("/var/etc/resolv.conf.dnscache", "r");
	if (! $fr) {
		printf("Error: cannot open resolv.conf.dnscache in tinydns_register_forwarding_servers().\n");
		return 1;
	}
	
	$lip = strlen("nameserver") + 1;
	$j = 0;
	$iprecords = "";
	while (!feof($fr)) {
		$routers = fgets($fr, 4096);
		$discard = ($routers[0] == "\n"); 
		if(!$discard) {
			if ($routerip = strstr($routers,"nameserver")) {
				$routerip = substr($routerip,$lip);
				if($routerip) {
					$j += 1;
					$routera = "{$routerip}";
					$iprecords .= $routera;
				}	
			}
		}	
	}
	fclose($fr);
	exec("echo 1 > /etc/dnscache/env/FORWARDONLY");
	if(is_dir("/etc/dnscache/root/servers/")) 
		exec("rm -R /etc/dnscache/root/servers/");
	exec("mkdir /etc/dnscache/root/servers/");
	$fr = fopen("/etc/dnscache/root/servers/@", "w");
	if (! $fr) {
		printf("Error: cannot write to /etc/dnscache/root/servers/@ in tinydns_dnscache_forwarding_servers().\n");
		return 1;
	}
	if($iprecords)
		fwrite($fr, $iprecords);
	fclose($fr);
}

/* This routine adds filenames to /etc/dnscache/root/servers/ with the contents pointing to the tinyDNS server */
function tinydns_create_soa_domain_list($dnsserverip) {
	if(file_exists("/service/tinydns/root/data"))
		$tinydns_data = file_get_contents("/service/tinydns/root/data");
	else
		$tinydns_data = "";
	
	$datalen = strlen($tinydns_data);
	$startofrecord = 0;
	while ($startofrecord < $datalen ) {	
		$endofrecord = strpos($tinydns_data,"\n",$startofrecord);
		$dnsrecord = substr($tinydns_data,$startofrecord,$endofrecord-$startofrecord);
		$startofrecord = $endofrecord + 1;
		
		$col1 = strpos($dnsrecord,":");
		$fqdn = substr($dnsrecord,1,$col1-1);
		if($fqdn) {
			$rtypes = tinydns_get_dns_record_type($dnsrecord);
			if($rtypes[0] == "SOA") {
				$fr = fopen("/etc/dnscache/root/servers/{$fqdn}", "w");
				if (! $fr) {
					printf("Error: cannot open /etc/dnscache/root/servers/{$fqdn} in tinydns_create_soa_domain_list().\n");
					return 1;
				}
				if($fqdn)fwrite($fr, $dnsserverip);
				fclose($fr);
			}
		}	
	}	
}

/* This function is not called */
/* At the moment there is no tagging of DNSroute to a WAN port. It needs to be added  */
function tinydns_register_forwarding_servers() {
	$fr = fopen("/var/etc/resolv.conf", "r");
	if (! $fr) {
		printf("Error: cannot open resolv.conf in tinydns_register_forwarding_servers().\n");
		return 1;
	}
	
	$lip = strlen("nameserver") + 1;
	$j = 0;
	$nsrecords = "";
	$arecords = "";
	while (!feof($fr)) {
		$routers = fgets($fr, 4096);
		$discard = ($routers[0] == "\n"); 
		if(!$discard) {
			if ($routerip = strstr($routers,"nameserver")) {
				$routerip = substr($routerip,$lip);
				if($routerip) {
					$j += 1;
					$routerfqdn = "DNSroute-{$j}.wan{$j}";
					$routerns = "&::{$routerfqdn}";
					$routera = "={$routerfqdn}:{$routerip}";
					$nsrecords .= $routerns . "\n";
					$arecords .= $routera;
				}	
			}
		}	
	}
	fclose($fr);
	$dnsroutes ="{$nsrecords}{$arecords}";
	return $dnsroutes;
}

function tinydns_register_root_servers() {
	$rootservers =<<<EOD
&::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
=a.root-servers.net:198.41.0.4
=b.root-servers.net:128.9.0.107
=c.root-servers.net:192.33.4.12
=d.root-servers.net:128.8.10.90
=e.root-servers.net:192.203.230.10
=f.root-servers.net:192.5.5.241
=g.root-servers.net:192.112.36.4
=h.root-servers.net:128.63.2.53
=i.root-servers.net:192.36.148.17
=j.root-servers.net:192.58.128.30
=k.root-servers.net:193.0.14.129
=l.root-servers.net:199.7.83.42
=m.root-servers.net:202.12.27.33

EOD;
	return $rootservers;
}

function dnscache_use_root_servers() {
	$rootservers =<<<EOD
198.41.0.4
128.9.0.107
192.33.4.12
128.8.10.90
192.203.230.10
192.5.5.241
192.112.36.4
128.63.2.53
192.36.148.17
192.58.128.30
193.0.14.129
199.7.83.42
202.12.27.33

EOD;

	exec("echo 0 > /etc/dnscache/env/FORWARDONLY");
	if(is_dir("/etc/dnscache/root/servers/")) 
		exec("rm -R /etc/dnscache/root/servers/");
	exec("mkdir /etc/dnscache/root/servers/");
	$fr = fopen("/etc/dnscache/root/servers/@", "w");
	if (! $fr) {
		printf("Error: cannot write to /etc/dnscache/root/servers/@ in dnscache_use_root_servers().\n");
		return 1;
	}
	fwrite($fr, $rootservers);
	fclose($fr);
}

?>