system: configurable hostname (device identity)

Add a device hostname settable from the CLI (`hostname <text>`) and the
System Settings page. The value is sanitized on ingest to JSON-safe
printable ASCII (<=23 chars), stored in a shared __xdata buffer, seeded
to "RTLPlayground" at boot, persisted through the startup-config, and
reported in /information.json. It lives in the common header so other
modules can advertise it (LLDP uses it as the System Name TLV).

html/config.js

@@ -25,6 +25,7 @@ const conf_cmds = [
   /^igmp\s+(on|off)$/,
   /^mtu\s+\d{1,2}\s+\d+$/,
   /^bw\s+(in|out)\s+\d{1,2}\s+\S+$/,
+  /^hostname\s+.{1,23}$/,
 ];
 const conf_overwrite = [
   /^ip\b/,
@@ -49,6 +50,7 @@ const conf_overwrite = [
   /^igmp\b/,
   /^mtu\s+\d{1,2}\b/,
   /^bw\s+(in|out)\s+\d{1,2}\b/,
+  /^hostname\b/,
 ];
 
 function parseConf(s){

html/i18n.js

@@ -138,6 +138,8 @@ var LANG = {
     sys_tab_console: 'Console',
     sys_heading: 'System Settings',
     sys_ip: 'IP address:',
+    sys_hostname: 'Hostname:',
+    sys_apply: 'Apply',
     sys_netmask: 'Netmask:',
     sys_gateway: 'Gateway:',
     sys_language: 'Language:',
@@ -317,6 +319,8 @@ var LANG = {
     sys_tab_console: 'コンソール',
     sys_heading: 'システム設定',
     sys_ip: 'IP アドレス:',
+    sys_hostname: 'ホスト名:',
+    sys_apply: '適用',
     sys_netmask: 'ネットマスク:',
     sys_gateway: 'ゲートウェイ:',
     sys_language: '言語:',
@@ -496,6 +500,8 @@ var LANG = {
     sys_tab_console: '控制台',
     sys_heading: '系统设置',
     sys_ip: 'IP 地址:',
+    sys_hostname: '主机名:',
+    sys_apply: '应用',
     sys_netmask: '子网掩码:',
     sys_gateway: '网关:',
     sys_language: '语言:',

html/system.html

@@ -25,6 +25,11 @@
 
     <div id="system-tab" class="tab-content active">
       <h1 data-i18n="sys_heading">System Settings</h1>
+      <div class="row">
+        <div class="lcol"> <label for="hostname" data-i18n="sys_hostname">Hostname:</label></div>
+        <div class="rcol"> <input id="hostname" type="text" maxlength="23" size="20"/>
+          <button onclick="hostSub()" data-i18n="sys_apply">Apply</button></div>
+      </div>
       <div class="row">
         <div class="lcol"> <label for="ip" data-i18n="sys_ip">IP address:</label></div>
         <div class="rcol"> <input id="ip" class="ip" type="text" minlength="7" maxlength="15" size="15"/></div>

html/system.js

@@ -48,6 +48,14 @@ async function cmdSub() {
 }
 
 
+async function hostSub() {
+  const h = document.getElementById("hostname").value;
+  try { await fetch('/cmd', { method: 'POST', body: "hostname " + h }); }
+  catch(err) { console.error(`Error: ${err}`); }
+  fetchIP();
+}
+
+
 async function sendConfig(c) {
   if (isSaving) return;
   isSaving = true;
@@ -123,6 +131,7 @@ function fetchIP() {
       document.getElementById("ip").value=s.ip_address;
       document.getElementById("netmask").value=s.ip_netmask;
       document.getElementById("gw").value=s.ip_gateway;
+      if (document.getElementById("hostname")) document.getElementById("hostname").value = s.hostname || "";
       clearInterval(systemInterval);
       // Fetch and populate the config textbox
       fetchConfig().then((configText) => {