fix(ook): address code review findings from Copilot PR review

- Fix XSS: escape ASCII output in innerHTML via escapeHtml()
- Fix deadlock: use put_nowait() for queue ops under ook_lock
- Fix SSE leak: add ook to moduleDestroyMap so switching modes
  closes the EventSource
- Fix RSSI: explicit null check preserves valid zero values in
  JSON export
- Add frame cap: trim oldest frames at 5000 to prevent unbounded
  memory growth on busy bands
- Validate timing params: wrap int() casts in try/except, return
  400 instead of 500 on invalid input
- Fix PWM hint: correct to short=0/long=1 matching rtl_433
  OOK_PWM convention (UI, JS hints, and cheat sheet)
- Fix inversion docstring: clarify fallback only applies when
  primary hex parse fails, not for valid decoded frames

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

routes/ook.py

@@ -75,12 +75,15 @@ def start_ook() -> Response:
             return jsonify({'status': 'error', 'message': str(e)}), 400
 
         # OOK flex decoder timing parameters
+        try:
             short_pulse = int(data.get('short_pulse', 300))
             long_pulse = int(data.get('long_pulse', 600))
             reset_limit = int(data.get('reset_limit', 8000))
             gap_limit = int(data.get('gap_limit', 5000))
             tolerance = int(data.get('tolerance', 150))
             min_bits = int(data.get('min_bits', 8))
+        except (ValueError, TypeError) as e:
+            return jsonify({'status': 'error', 'message': f'Invalid timing parameter: {e}'}), 400
         deduplicate = bool(data.get('deduplicate', False))
 
         rtl_tcp_host = data.get('rtl_tcp_host') or None
@@ -195,7 +198,10 @@ def start_ook() -> Response:
             app_module.ook_process._stop_parser = stop_event
             app_module.ook_process._parser_thread = parser_thread
 
-            app_module.ook_queue.put({'type': 'status', 'status': 'started'})
+            try:
+                app_module.ook_queue.put_nowait({'type': 'status', 'status': 'started'})
+            except queue.Full:
+                logger.warning("OOK 'started' status dropped — queue full")
 
             return jsonify({
                 'status': 'started',
@@ -244,7 +250,10 @@ def stop_ook() -> Response:
                 app_module.release_sdr_device(ook_active_device)
                 ook_active_device = None
 
-            app_module.ook_queue.put({'type': 'status', 'status': 'stopped'})
+            try:
+                app_module.ook_queue.put_nowait({'type': 'status', 'status': 'stopped'})
+            except queue.Full:
+                logger.warning("OOK 'stopped' status dropped — queue full")
             return jsonify({'status': 'stopped'})
 
         return jsonify({'status': 'not_running'})

static/js/core/cheat-sheets.js

@@ -34,7 +34,7 @@ const CheatSheets = (function () {
             description: 'Decodes raw On-Off Keying (OOK) signals via rtl_433 flex decoder. Captures frames with configurable pulse timing and displays raw bits, hex, and ASCII — useful for reverse-engineering unknown ISM-band protocols.',
             whatToExpect: 'Decoded bit sequences, hex payloads, and ASCII interpretation. Each frame shows bit count, timestamp, and optional RSSI.',
             tips: [
-                '<strong>Identifying modulation</strong> — <em>PWM</em>: pulse widths vary (short=1, long=0), gaps constant — most common for ISM remotes/sensors. <em>PPM</em>: pulses constant, gap widths encode data. <em>Manchester</em>: self-clocking, equal-width pulses, data in transitions.',
+                '<strong>Identifying modulation</strong> — <em>PWM</em>: pulse widths vary (short=0, long=1), gaps constant — most common for ISM remotes/sensors. <em>PPM</em>: pulses constant, gap widths encode data. <em>Manchester</em>: self-clocking, equal-width pulses, data in transitions.',
                 '<strong>Finding pulse timing</strong> — Run <code>rtl_433 -f 433.92M -A</code> in a terminal to auto-analyze signals. It prints detected pulse widths (short/long) and gap timings. Use those values in the Short/Long Pulse fields.',
                 '<strong>Common ISM timings</strong> — 300/600µs (weather stations, door sensors), 400/800µs (car keyfobs), 500/1500µs (garage doors, doorbells), 500µs Manchester (tire pressure monitors).',
                 '<strong>Frequencies to try</strong> — 315 MHz (North America keyfobs), 433.920 MHz (global ISM), 868 MHz (Europe ISM), 915 MHz (US ISM/meters).',

static/js/modes/ook.js

@@ -10,6 +10,7 @@ var OokMode = (function () {
     'use strict';
 
     var DEFAULT_FREQ_PRESETS = ['433.920', '315.000', '868.000', '915.000'];
+    var MAX_FRAMES = 5000;
 
     var state = {
         running: false,
@@ -162,6 +163,13 @@ var OokMode = (function () {
         state.frames.push(msg);
         state.frameCount++;
 
+        // Trim oldest frames when buffer exceeds cap
+        if (state.frames.length > MAX_FRAMES) {
+            state.frames.splice(0, state.frames.length - MAX_FRAMES);
+            var panel = document.getElementById('ookOutput');
+            if (panel && panel.firstChild) panel.removeChild(panel.firstChild);
+        }
+
         var countEl = document.getElementById('ookFrameCount');
         if (countEl) countEl.textContent = state.frameCount + ' frames';
         var barEl = document.getElementById('ookStatusBarFrames');
@@ -237,7 +245,7 @@ var OokMode = (function () {
             '</span>' +
             '<br>' +
             '<span style="padding-left:8em; color:' + (hasPrintable ? '#aaffcc' : '#555') + '; font-family:var(--font-mono); font-size:10px">' +
-            'ascii: ' + interp.ascii +
+            'ascii: ' + (typeof escapeHtml === 'function' ? escapeHtml(interp.ascii) : interp.ascii) +
             '</span>';
 
         div.style.cssText = 'font-size:11px; padding: 4px 0; border-bottom: 1px solid #1a1a1a; line-height:1.6;';
@@ -328,7 +336,7 @@ var OokMode = (function () {
             return {
                 timestamp: msg.timestamp,
                 bit_count: msg.bit_count,
-                rssi: msg.rssi || null,
+                rssi: (msg.rssi !== undefined && msg.rssi !== null) ? msg.rssi : null,
                 hex: interp.hex,
                 ascii: interp.ascii,
                 inverted: msg.inverted,
@@ -382,7 +390,7 @@ var OokMode = (function () {
 
         // Update timing hint
         var hints = {
-            pwm: 'Short pulse = 1, long pulse = 0. Most common for ISM OOK.',
+            pwm: 'Short pulse = 0, long pulse = 1. Most common for ISM OOK.',
             ppm: 'Short gap = 0, long gap = 1. Pulse position encoding.',
             manchester: 'Rising edge = 1, falling edge = 0. Self-clocking.',
         };

templates/index.html

@@ -4107,6 +4107,7 @@
                 vdl2: () => { if (vdl2MainEventSource) { vdl2MainEventSource.close(); vdl2MainEventSource = null; } },
                 radiosonde: () => { if (radiosondeEventSource) { radiosondeEventSource.close(); radiosondeEventSource = null; } },
                 meteor: () => typeof MeteorScatter !== 'undefined' && MeteorScatter.destroy?.(),
+                ook: () => typeof OokMode !== 'undefined' && OokMode.destroy?.(),
             };
             return moduleDestroyMap[mode] || null;
         }

templates/partials/modes/ook.html

@@ -57,7 +57,7 @@
             </div>
             <input type="hidden" id="ookEncoding" value="pwm">
             <p id="ookEncodingHint" class="info-text" style="font-size: 10px; color: var(--text-dim); margin-top: 4px;">
-                Short pulse = 1, long pulse = 0. Most common for ISM OOK.
+                Short pulse = 0, long pulse = 1. Most common for ISM OOK.
             </p>
         </div>
     </div>

utils/ook.py

@@ -77,9 +77,11 @@ def ook_parser_thread(
     """Thread function: reads rtl_433 JSON output and emits OOK frame events.
 
     Handles the three rtl_433 hex-output field names (``codes``, ``code``,
-    ``data``) and falls back to bit-inverted parsing when the primary hex
-    parse produces no result — needed for transmitters that swap the
-    short/long pulse mapping.
+    ``data``) and, if the initial hex decoding fails, retries with an
+    inverted bit interpretation.  This inversion fallback is only applied
+    when the primary parse yields no usable hex; it does not attempt to
+    reinterpret successfully decoded frames that merely swap the short/long
+    pulse mapping.
 
     Args:
         rtl_stdout: rtl_433 stdout pipe.