pfSense

/* This function will remove entries from dhcpd.leases that would otherwise

 * overlap with static DHCP reservations. If we don't clean these out,

 * then DHCP will print a warning in the logs about a duplicate lease

 */

function dhcp_clean_leases() {

	global $g, $config;

	$leasesfile = "{$g['dhcpd_chroot_path']}/var/db/dhcpd.leases";

	if (!file_exists($leasesfile))

		return;

	/* Build list of static MACs */

	$staticmacs = array();

	foreach($config['interfaces'] as $ifname => $ifarr)

		if (is_array($config['dhcpd'][$ifname]['staticmap']))

			foreach($config['dhcpd'][$ifname]['staticmap'] as $static)

				$staticmacs[] = $static['mac'];

	/* Read existing leases */

	$leases_contents = explode("\n", file_get_contents($leasesfile));

	$newleases_contents = array();

	$i=0;

	while ($i < count($leases_contents)) {

		/* Find a lease definition */

		if (substr($leases_contents[$i], 0, 6) == "lease ") {

			$templease = array();

			$thismac = "";

			/* Read to the end of the lease declaration */

			do {

				if (substr($leases_contents[$i], 0, 20) == "  hardware ethernet ")

					$thismac = substr($leases_contents[$i], 20, 17);

				$templease[] = $leases_contents[$i];

				$i++;

			} while ($leases_contents[$i-1] != "}");

			/* Check for a matching MAC address and if not present, keep it. */

			if (! in_array($thismac, $staticmacs))

				$newleases_contents = array_merge($newleases_contents, $templease);

		} else {

			/* It's a line we want to keep, copy it over. */

			$newleases_contents[] = $leases_contents[$i];

			$i++;

		}

	}

	/* Write out the new leases file */

	$fd = fopen($leasesfile, 'w');

	fwrite($fd, implode("\n", $newleases_contents));

	fclose($fd);

}

	/* Stop DHCP so we can cleanup leases */

	killbyname("dhcpd");

	dhcp_clean_leases();