🍓 Sync 2026-09-15 02:13:06

luci-mod-status/root/usr/libexec/luci-client-history

@@ -3,7 +3,8 @@
 'use strict';
 import { readfile, writefile, rename, chmod } from 'fs';
 import { connect } from 'ubus';
-import { arp_leases, update_history } from 'luci.client_history';
+import { netbios_names } from 'luci.client_names';
+import { arp_leases, update_history, reverse_names } from 'luci.client_history';
 
 const path = '/tmp/luci-client-history.json';
 const boot_id = trim(readfile('/proc/sys/kernel/random/boot_id') || '');
@@ -13,11 +14,24 @@ let previous = {};
 try { previous = json(readfile(path) || '{}'); } catch (e) {}
 const bus = connect();
 let current = bus ? bus.call('luci-rpc', 'getDHCPLeases', {}) : null;
+current ||= {};
+const active = arp_leases(readfile('/proc/net/arp'));
+const reverse_dns = reverse_names(previous, current, active, boot_id,
+	int(split(readfile('/proc/uptime'), ' ')[0]), function(addrs) {
+		let names = bus ? (bus.call('network.rrdns', 'lookup', { addrs, timeout: 1000, limit: 8 }) || {}) : {};
+		return { ...names, ...netbios_names(filter(addrs, ip => !names[ip])) };
+	});
 if (bus)
 	bus.disconnect();
-current ||= {};
-current.dhcp_leases = [ ...(current.dhcp_leases || []), ...arp_leases(readfile('/proc/net/arp')) ];
-const next = sprintf('%J', update_history(previous, current, boot_id));
+// Recheck ownership after the asynchronous DNS query.
+const owners = {};
+for (let lease in arp_leases(readfile('/proc/net/arp')))
+	owners[lease.ipaddr] = lease.macaddr;
+current.dhcp_leases = [ ...(current.dhcp_leases || []),
+	...filter(active, lease => owners[lease.ipaddr] == lease.macaddr) ];
+const result = update_history(previous, current, boot_id);
+result.reverse_dns = reverse_dns;
+const next = sprintf('%J', result);
 if (next != readfile(path)) {
 	if (writefile(path + '.new', next) != length(next))
 		exit(1);

luci-mod-status/root/usr/share/ucode/luci/client_history.uc

@@ -47,3 +47,43 @@ export function update_history(previous, current, boot_id) {
 	}
 	return result;
 };
+
+// Cache both successful and unsuccessful PTR lookups. Bind results to MAC + IP
+// so an address handed to another client cannot inherit the former name.
+export function reverse_names(previous, current, active, boot_id, now, lookup) {
+	let old = type(previous) == 'object' && previous.boot_id == boot_id &&
+		type(previous.reverse_dns) == 'object' ? previous.reverse_dns : {};
+	let cache = {}, named = {}, pending = [];
+	for (let family in ['dhcp_leases', 'dhcp6_leases'])
+		for (let lease in current[family] || [])
+			if (type(lease.hostname) == 'string' && length(lease.hostname) &&
+			    lease.hostname != '*' && lease.hostname != lease.ipaddr && lease.macaddr)
+				named[uc(lease.macaddr)] = true;
+	for (let lease in active) {
+		if (named[lease.macaddr])
+			continue;
+		let key = lease.macaddr + '@' + lease.ipaddr;
+		let entry = type(old[key]) == 'object' ? old[key] : {};
+		cache[key] = entry;
+		if ((!entry.next || entry.next <= now) && length(pending) < 32) {
+			push(pending, lease.ipaddr);
+			entry.next = now + 300;
+		}
+	}
+	let answers = length(pending) ? lookup(pending) : {};
+	for (let lease in active) {
+		let entry = cache[lease.macaddr + '@' + lease.ipaddr];
+		if (!entry)
+			continue;
+		let name = answers?.[lease.ipaddr];
+		if (type(name) == 'string') {
+			name = replace(name, /\.$/, '');
+			if (length(name) <= 253 && match(name, /^[a-z0-9_][a-z0-9_.-]*$/i) &&
+			    !match(name, /^[0-9.]+$/))
+				entry.hostname = name;
+		}
+		if (entry.hostname)
+			lease.hostname = entry.hostname;
+	}
+	return cache;
+};

luci-mod-status/root/usr/share/ucode/luci/client_names.uc

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: Apache-2.0
+// RFC 1002 NBSTAT: unicast queries only, to known LAN clients.
+import { create, poll, AF_INET, SOCK_DGRAM, POLLIN, MSG_DONTWAIT } from 'socket';
+
+function byte(data, offset) { return ord(substr(data, offset, 1)); };
+function word(data, offset) { return byte(data, offset) * 256 + byte(data, offset + 1); };
+function skip_name(data, offset) {
+	while (offset < length(data)) {
+		let size = byte(data, offset++);
+		if (!size) return offset;
+		if ((size & 0xc0) == 0xc0)
+			return offset < length(data) ? offset + 1 : -1;
+		if (size > 63 || offset + size > length(data)) return -1;
+		offset += size;
+	}
+	return -1;
+};
+
+export function nbstat_name(data, id) {
+	if (type(data) != 'string' || length(data) < 12 || word(data, 0) != id ||
+	    (word(data, 2) & 0xfa0f) != 0x8000 || word(data, 6) != 1)
+		return null;
+	let offset = 12;
+	for (let i = 0; i < word(data, 4); i++) {
+		offset = skip_name(data, offset);
+		if (offset < 0 || offset + 4 > length(data)) return null;
+		offset += 4;
+	}
+	offset = skip_name(data, offset);
+	if (offset < 0 || offset + 11 > length(data) || word(data, offset) != 0x21 ||
+	    word(data, offset + 2) != 1) return null;
+	let size = word(data, offset + 8);
+	offset += 10;
+	if (size < 1 || offset + size > length(data)) return null;
+	let count = byte(data, offset++), server = null;
+	if (1 + count * 18 > size) return null;
+	for (let i = 0; i < count; i++, offset += 18) {
+		let suffix = byte(data, offset + 15), flags = word(data, offset + 16);
+		let name = trim(substr(data, offset, 15));
+		if ((flags & 0x8000) || !match(name, /^[a-z0-9_][a-z0-9_.-]*$/i)) continue;
+		if (suffix == 0) return name;
+		if (suffix == 0x20) server = name;
+	}
+	return server;
+};
+
+export function netbios_names(addresses) {
+	let jobs = [], result = {};
+	for (let ip in addresses) {
+		if (length(jobs) >= 32) break;
+		let sock = create(AF_INET, SOCK_DGRAM);
+		if (!sock) continue;
+		let id = (int(time()) + length(jobs)) & 65535;
+		let query = chr(id >> 8) + chr(id & 255) + '\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00' +
+			'\x20CKAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\x00\x00\x21\x00\x01';
+		if (!sock.connect({ family: AF_INET, address: ip, port: 137 }) || sock.send(query) != length(query)) {
+			sock.close();
+			continue;
+		}
+		push(jobs, [sock, POLLIN, ip, id]);
+	}
+	// Batch all clients; never wait one second per address.
+	for (let round = 0; round < 4 && length(jobs); round++) {
+		let events = poll(250, ...jobs) || [];
+		for (let event in events) {
+			if (!event[1]) continue;
+			let name = nbstat_name(event[0].recv(4096, MSG_DONTWAIT), event[3]);
+			if (name) result[event[2]] = name;
+			event[0].close();
+			jobs = filter(jobs, job => job[2] != event[2]);
+		}
+	}
+	for (let job in jobs) job[0].close();
+	return result;
+};