libreCMC/package/luci/modules/luci-base/luasrc/view/lease_status.htm

<script type="text/javascript">//<![CDATA[
	XHR.poll(-1, '<%=url('admin/dhcplease_status')%>', null,
		function(x, st)
		{
			var tb = document.getElementById('lease_status_table');
			if (st && st[0] && tb)
			{
				var rows = [];

				for (var i = 0; i < st[0].length; i++)
				{
					var timestr;

					if (st[0][i].expires === false)
						timestr = '<em><%:unlimited%></em>';
					else if (st[0][i].expires <= 0)
						timestr = '<em><%:expired%></em>';
					else
						timestr = String.format('%t', st[0][i].expires);

					rows.push([
						st[0][i].hostname || '?',
						st[0][i].ipaddr,
						st[0][i].macaddr,
						timestr
					]);
				}

				cbi_update_table(tb, rows, '<em><%:There are no active leases.%></em>');
			}

			var tb6 = document.getElementById('lease6_status_table');
			if (st && st[1] && tb6)
			{
				tb6.parentNode.style.display = 'block';

				var rows = [];

				for (var i = 0; i < st[1].length; i++)
				{
					var timestr;

					if (st[1][i].expires === false)
						timestr = '<em><%:unlimited%></em>';
					else if (st[1][i].expires <= 0)
						timestr = '<em><%:expired%></em>';
					else
						timestr = String.format('%t', st[1][i].expires);

					var name = st[1][i].hostname,
					    hint = st[1][i].host_hint;

					rows.push([
						hint ? '%h (%h)'.format(name || '?', hint) : (name || '?'),
						st[1][i].ip6addr,
						st[1][i].duid,
						timestr
					]);
				}

				cbi_update_table(tb6, rows, '<em><%:There are no active leases.%></em>');
			}
		}
	);
//]]></script>

<div class="cbi-section">
	<h3><%:Active DHCP Leases%></h3>
	<div class="table" id="lease_status_table">
		<div class="tr table-titles">
			<div class="th"><%:Hostname%></div>
			<div class="th"><%:IPv4-Address%></div>
			<div class="th"><%:MAC-Address%></div>
			<div class="th"><%:Leasetime remaining%></div>
		</div>
		<div class="tr placeholder">
			<div class="td"><em><%:Collecting data...%></em></div>
		</div>
	</div>
</div>

<%
	local fs = require "nixio.fs"
	local has_ipv6 = fs.access("/proc/net/ipv6_route")

	if has_ipv6 then
-%>
	<div class="cbi-section" style="display:none">
		<h3><%:Active DHCPv6 Leases%></h3>
		<div class="table" id="lease6_status_table">
			<div class="tr table-titles">
				<div class="th"><%:Host%></div>
				<div class="th"><%:IPv6-Address%></div>
				<div class="th"><%:DUID%></div>
				<div class="th"><%:Leasetime remaining%></div>
			</div>
			<div class="tr placeholder">
				<div class="td"><em><%:Collecting data...%></em></div>
			</div>
		</div>
	</div>
<% end -%>