fix(connection): live-session TCP link meter (supersedes #811)

docs/troubleshooting.md

@@ -605,6 +605,14 @@ IPv6 addresses work for Meshtastic Wi‑Fi, MeshCore TCP, and Reticulum RNode Wi
 
 **Address examples:** `192.168.1.10:4403`, `meshtastic.local:4403`, `[fd00::1]:4403`.
 
+### Connection panel Link quality (TCP) shows "—" or unexpected latency
+
+**Cause:** For **Meshtastic WiFi/TCP** and **MeshCore TCP/IP SoftAP**, the Connection panel signal bars reflect **live-session responsiveness** — an EWMA of write→first-data delay on the already-open TCP socket — not a separate connect probe. Bars may show **"—"** until traffic has produced a sample, or after ~2 minutes without a completed sample (covers idle heartbeat gaps). Meshtastic **WiFi/HTTP** still uses a `/json/report` RTT probe (separate from the TCP session). Reticulum hub/RMAP rows still use a short-lived TCP connect probe (different risk profile).
+
+**Why not a second TCP connect?** Probing the same `host:port` as the live session every few seconds can RST ESP32/lwIP-class devices (see PR discussion around competing connections).
+
+**Fix:** Exercise the link (chat, NodeDB traffic, companion RPCs). If bars stay empty while the session is healthy, that is expected during idle gaps; reconnect if the session itself drops.
+
 ### Meshtastic HTTP fails immediately with "Invalid host format"
 
 **Cause:** Builds before v5.21.x validated the hostname incorrectly when the address included a port (`192.168.1.10:443`), rejecting every HTTP connect.

src/main/index.contract.test.ts

@@ -389,6 +389,31 @@ describe('Host link quality IPC (source contract)', () => {
     expect(INDEX_SOURCE).toContain("webContents.send('noble-ble-link-rssi'");
     expect(INDEX_SOURCE).toContain("ipcMain.handle('hostLink:probeHttpRtt'");
     expect(INDEX_SOURCE).toContain("ipcMain.handle('hostLink:probeTcpRtt'");
+    expect(INDEX_SOURCE).toContain("ipcMain.handle('hostLink:getSessionMeter'");
+  });
+
+  it('wires live-session meters on both Meshtastic and MeshCore TCP bridges', () => {
+    expect(INDEX_SOURCE).toContain("resetLiveSessionMeter('meshtastic')");
+    expect(INDEX_SOURCE).toContain("resetLiveSessionMeter('meshcore')");
+    expect(INDEX_SOURCE).toContain("noteLiveSessionWrite('meshtastic')");
+    expect(INDEX_SOURCE).toContain("noteLiveSessionWrite('meshcore')");
+    expect(INDEX_SOURCE).toContain("noteLiveSessionData('meshtastic')");
+    expect(INDEX_SOURCE).toContain("noteLiveSessionData('meshcore')");
+    expect(INDEX_SOURCE).toContain("clearLiveSessionMeter('meshtastic')");
+    expect(INDEX_SOURCE).toContain("clearLiveSessionMeter('meshcore')");
+    // Accounting must ignore superseded sockets (same active-ref guard as #792 disconnect IPC).
+    expect(INDEX_SOURCE).toMatch(
+      /if \(meshcoreTcpSocket === socket\) \{\s*noteLiveSessionData\('meshcore'\)/,
+    );
+    expect(INDEX_SOURCE).toMatch(
+      /if \(meshtasticTcpSocket === socket\) \{\s*noteLiveSessionData\('meshtastic'\)/,
+    );
+    expect(INDEX_SOURCE).toMatch(
+      /if \(meshcoreTcpSocket === sock\) \{\s*noteLiveSessionWrite\('meshcore'\)/,
+    );
+    expect(INDEX_SOURCE).toMatch(
+      /if \(meshtasticTcpSocket === sock\) \{\s*noteLiveSessionWrite\('meshtastic'\)/,
+    );
   });
 });
 
@@ -399,6 +424,7 @@ describe('Host link quality preload surface (source contract)', () => {
     expect(PRELOAD_SOURCE).toContain('hostLink:');
     expect(PRELOAD_SOURCE).toContain("ipcRenderer.invoke('hostLink:probeHttpRtt'");
     expect(PRELOAD_SOURCE).toContain("ipcRenderer.invoke('hostLink:probeTcpRtt'");
+    expect(PRELOAD_SOURCE).toContain("ipcRenderer.invoke('hostLink:getSessionMeter'");
   });
 });
 

src/main/index.ipc-security.test.ts

@@ -116,11 +116,11 @@ describe('meshtastic:tcp-write byte validation (source contract)', () => {
   it('destroys prior socket before opening a new meshtastic tcp connection', () => {
     const handlerIdx = INDEX_SOURCE.indexOf("ipcMain.handle('meshtastic:tcp-connect'");
     expect(handlerIdx).toBeGreaterThan(-1);
-    const handlerBody = INDEX_SOURCE.slice(handlerIdx, handlerIdx + 1200);
+    const handlerBody = INDEX_SOURCE.slice(handlerIdx, handlerIdx + 1400);
     // Null the active ref before destroy so the superseded close does not emit
     // meshtastic:tcp-disconnected against a healthy replacement (#792).
     expect(handlerBody).toMatch(
-      /const prev = meshtasticTcpSocket;\s*meshtasticTcpSocket = null;\s*prev\.destroy\(\)/,
+      /const prev = meshtasticTcpSocket;\s*meshtasticTcpSocket = null;\s*clearLiveSessionMeter\('meshtastic'\);\s*prev\.destroy\(\)/,
     );
   });
 
@@ -131,7 +131,7 @@ describe('meshtastic:tcp-write byte validation (source contract)', () => {
     expect(handlerIdx).toBeGreaterThan(-1);
     const closeIdx = INDEX_SOURCE.indexOf("socket.on('close'", handlerIdx);
     expect(closeIdx).toBeGreaterThan(handlerIdx);
-    const closeBody = INDEX_SOURCE.slice(closeIdx, closeIdx + 600);
+    const closeBody = INDEX_SOURCE.slice(closeIdx, closeIdx + 900);
     expect(closeBody).toContain('if (meshtasticTcpSocket === socket)');
     expect(closeBody).toContain("mainWindow?.webContents.send('meshtastic:tcp-disconnected')");
     // Emit must be inside the active-socket guard (not before it).
@@ -146,9 +146,9 @@ describe('meshtastic:tcp-write byte validation (source contract)', () => {
   it('nulls meshtasticTcpSocket before destroy on disconnect (PR #792)', () => {
     const handlerIdx = INDEX_SOURCE.indexOf("ipcMain.handle('meshtastic:tcp-disconnect'");
     expect(handlerIdx).toBeGreaterThan(-1);
-    const handlerBody = INDEX_SOURCE.slice(handlerIdx, handlerIdx + 400);
+    const handlerBody = INDEX_SOURCE.slice(handlerIdx, handlerIdx + 500);
     expect(handlerBody).toMatch(
-      /const prev = meshtasticTcpSocket;\s*meshtasticTcpSocket = null;\s*prev\.destroy\(\)/,
+      /const prev = meshtasticTcpSocket;\s*meshtasticTcpSocket = null;\s*clearLiveSessionMeter\('meshtastic'\);\s*prev\.destroy\(\)/,
     );
   });
 
@@ -393,16 +393,16 @@ describe('meshcore:tcp-connect hostname validation (source contract)', () => {
   it('nulls meshcoreTcpSocket before destroy on connect-replace and disconnect (PR #792)', () => {
     const connectIdx = INDEX_SOURCE.indexOf("ipcMain.handle('meshcore:tcp-connect'");
     expect(connectIdx).toBeGreaterThan(-1);
-    const connectBody = INDEX_SOURCE.slice(connectIdx, connectIdx + 1200);
+    const connectBody = INDEX_SOURCE.slice(connectIdx, connectIdx + 1400);
     expect(connectBody).toMatch(
-      /const prev = meshcoreTcpSocket;\s*meshcoreTcpSocket = null;\s*prev\.destroy\(\)/,
+      /const prev = meshcoreTcpSocket;\s*meshcoreTcpSocket = null;\s*clearLiveSessionMeter\('meshcore'\);\s*prev\.destroy\(\)/,
     );
 
     const disconnectIdx = INDEX_SOURCE.indexOf("ipcMain.handle('meshcore:tcp-disconnect'");
     expect(disconnectIdx).toBeGreaterThan(-1);
-    const disconnectBody = INDEX_SOURCE.slice(disconnectIdx, disconnectIdx + 400);
+    const disconnectBody = INDEX_SOURCE.slice(disconnectIdx, disconnectIdx + 500);
     expect(disconnectBody).toMatch(
-      /const prev = meshcoreTcpSocket;\s*meshcoreTcpSocket = null;\s*prev\.destroy\(\)/,
+      /const prev = meshcoreTcpSocket;\s*meshcoreTcpSocket = null;\s*clearLiveSessionMeter\('meshcore'\);\s*prev\.destroy\(\)/,
     );
   });
 
@@ -433,6 +433,19 @@ describe('meshcore:tcp-connect hostname validation (source contract)', () => {
   });
 });
 
+describe('hostLink:getSessionMeter validation (source contract)', () => {
+  it('rejects protocols other than meshtastic/meshcore', () => {
+    const handlerIdx = INDEX_SOURCE.indexOf("ipcMain.handle('hostLink:getSessionMeter'");
+    expect(handlerIdx).toBeGreaterThan(-1);
+    const handlerBody = INDEX_SOURCE.slice(handlerIdx, handlerIdx + 400);
+    expect(handlerBody).toContain("assertIpcSender(event, 'hostLink:getSessionMeter')");
+    expect(handlerBody).toContain("protocol !== 'meshtastic'");
+    expect(handlerBody).toContain("protocol !== 'meshcore'");
+    expect(handlerBody).toContain("throw new Error('Invalid protocol')");
+    expect(handlerBody).toContain('snapshotLiveSessionMeter(');
+  });
+});
+
 // ─── meshtastic:tcp-connect hostname validation ──────────────────────
 
 describe('meshtastic:tcp-connect hostname validation (source contract)', () => {
@@ -568,6 +581,7 @@ describe('privileged IPC sender validation (source contract)', () => {
     'meshtastic:tcp-connect',
     'meshtastic:tcp-write',
     'meshtastic:tcp-disconnect',
+    'hostLink:getSessionMeter',
     'noble-ble-connect',
     'noble-ble-disconnect',
     'notify:message',
@@ -637,7 +651,7 @@ describe('privileged IPC sender validation (source contract)', () => {
   it('meshtastic tcp-connect uses connect timeout', () => {
     expect(INDEX_SOURCE).toContain('MESHTASTIC_TCP_CONNECT_TIMEOUT_MS');
     expect(INDEX_SOURCE).toMatch(
-      /meshtastic:tcp-connect[\s\S]{0,1200}meshtastic:tcp-connect: connection timeout/,
+      /meshtastic:tcp-connect[\s\S]{0,1800}meshtastic:tcp-connect: connection timeout/,
     );
   });
 

src/main/index.ts

@@ -120,6 +120,13 @@ import {
   linuxWebBluetoothDeviceSelection,
 } from './linuxWebBluetoothDeviceSelection';
 import { listMeshcoreDmPeersFromDb, listMeshtasticDmPeersFromDb } from './listDmPeers';
+import {
+  clearLiveSessionMeter,
+  noteLiveSessionData,
+  noteLiveSessionWrite,
+  resetLiveSessionMeter,
+  snapshotLiveSessionMeter,
+} from './live-session-meter';
 import {
   clearLogFile,
   exportLogTo,
@@ -6123,6 +6130,7 @@ ipcMain.handle('meshcore:tcp-connect', (event, host: string, port: number) => {
       // meshcore:tcp-disconnected (renderer reconnect is driven by that event — #792).
       const prev = meshcoreTcpSocket;
       meshcoreTcpSocket = null;
+      clearLiveSessionMeter('meshcore');
       prev.destroy();
     }
     const socketHost = formatHostForSocket(host);
@@ -6135,7 +6143,10 @@ ipcMain.handle('meshcore:tcp-connect', (event, host: string, port: number) => {
     const connectTimeout = setTimeout(() => {
       if (settled) return;
       settled = true;
-      if (meshcoreTcpSocket === socket) meshcoreTcpSocket = null;
+      if (meshcoreTcpSocket === socket) {
+        meshcoreTcpSocket = null;
+        clearLiveSessionMeter('meshcore');
+      }
       socket.destroy();
       reject(new Error('meshcore:tcp-connect: connection timeout'));
     }, MESHCORE_TCP_CONNECT_TIMEOUT_MS);
@@ -6145,6 +6156,7 @@ ipcMain.handle('meshcore:tcp-connect', (event, host: string, port: number) => {
       logDeviceConnection(
         `transport=tcp stack=meshcore host=${sanitizeLogMessage(socketHost)} port=${p}`,
       );
+      resetLiveSessionMeter('meshcore');
       if (!settled) {
         settled = true;
         resolve();
@@ -6166,6 +6178,10 @@ ipcMain.handle('meshcore:tcp-connect', (event, host: string, port: number) => {
         }
         return;
       }
+      // Superseded sockets must not update the live session meter (#792 connect-replace).
+      if (meshcoreTcpSocket === socket) {
+        noteLiveSessionData('meshcore');
+      }
       mainWindow?.webContents.send('meshcore:tcp-data', new Uint8Array(chunk));
     });
     socket.on('close', (hadError) => {
@@ -6187,6 +6203,7 @@ ipcMain.handle('meshcore:tcp-connect', (event, host: string, port: number) => {
       // (renderer reconnect is driven by this event — see #792).
       if (meshcoreTcpSocket === socket) {
         meshcoreTcpSocket = null;
+        clearLiveSessionMeter('meshcore');
         mainWindow?.webContents.send('meshcore:tcp-disconnected');
       }
     });
@@ -6229,6 +6246,10 @@ ipcMain.handle('meshcore:tcp-write', (event, bytes: number[]) => {
         console.error('[IPC] meshcore:tcp-write error:', sanitizeLogMessage(err.message));
         reject(err);
       } else {
+        // Ignore write completions from a superseded socket.
+        if (meshcoreTcpSocket === sock) {
+          noteLiveSessionWrite('meshcore');
+        }
         resolve();
       }
     });
@@ -6242,6 +6263,7 @@ ipcMain.handle('meshcore:tcp-disconnect', (event) => {
     // Null before destroy so this teardown close is not reported as a live link drop.
     const prev = meshcoreTcpSocket;
     meshcoreTcpSocket = null;
+    clearLiveSessionMeter('meshcore');
     prev.destroy();
   }
 });
@@ -6272,6 +6294,7 @@ ipcMain.handle('meshtastic:tcp-connect', (event, host: string, port: number) =>
       // meshtastic:tcp-disconnected (renderer reconnect is driven by that event — #792).
       const prev = meshtasticTcpSocket;
       meshtasticTcpSocket = null;
+      clearLiveSessionMeter('meshtastic');
       prev.destroy();
     }
     const socketHost = formatHostForSocket(host);
@@ -6282,7 +6305,10 @@ ipcMain.handle('meshtastic:tcp-connect', (event, host: string, port: number) =>
     const connectTimeout = setTimeout(() => {
       if (settled) return;
       settled = true;
-      if (meshtasticTcpSocket === socket) meshtasticTcpSocket = null;
+      if (meshtasticTcpSocket === socket) {
+        meshtasticTcpSocket = null;
+        clearLiveSessionMeter('meshtastic');
+      }
       socket.destroy();
       reject(new Error('meshtastic:tcp-connect: connection timeout'));
     }, MESHTASTIC_TCP_CONNECT_TIMEOUT_MS);
@@ -6292,6 +6318,7 @@ ipcMain.handle('meshtastic:tcp-connect', (event, host: string, port: number) =>
       logDeviceConnection(
         `transport=tcp stack=meshtastic host=${sanitizeLogMessage(socketHost)} port=${p}`,
       );
+      resetLiveSessionMeter('meshtastic');
       if (!settled) {
         settled = true;
         resolve();
@@ -6313,6 +6340,10 @@ ipcMain.handle('meshtastic:tcp-connect', (event, host: string, port: number) =>
         }
         return;
       }
+      // Superseded sockets must not update the live session meter (#792 connect-replace).
+      if (meshtasticTcpSocket === socket) {
+        noteLiveSessionData('meshtastic');
+      }
       mainWindow?.webContents.send('meshtastic:tcp-data', new Uint8Array(chunk));
     });
     socket.on('close', (hadError) => {
@@ -6323,6 +6354,7 @@ ipcMain.handle('meshtastic:tcp-connect', (event, host: string, port: number) =>
       // (renderer reconnect is driven by this event — see #792).
       if (meshtasticTcpSocket === socket) {
         meshtasticTcpSocket = null;
+        clearLiveSessionMeter('meshtastic');
         mainWindow?.webContents.send('meshtastic:tcp-disconnected');
       }
     });
@@ -6365,6 +6397,10 @@ ipcMain.handle('meshtastic:tcp-write', (event, bytes: number[]) => {
         console.error('[IPC] meshtastic:tcp-write error:', sanitizeLogMessage(err.message));
         reject(err);
       } else {
+        // Ignore write completions from a superseded socket.
+        if (meshtasticTcpSocket === sock) {
+          noteLiveSessionWrite('meshtastic');
+        }
         resolve();
       }
     });
@@ -6378,6 +6414,7 @@ ipcMain.handle('meshtastic:tcp-disconnect', (event) => {
     // Null before destroy so this teardown close is not reported as a live link drop.
     const prev = meshtasticTcpSocket;
     meshtasticTcpSocket = null;
+    clearLiveSessionMeter('meshtastic');
     prev.destroy();
   }
 });
@@ -6516,6 +6553,14 @@ ipcMain.handle('hostLink:probeTcpRtt', async (event, host: unknown, port: unknow
   return probeTcpRttMs(host, port as number);
 });
 
+ipcMain.handle('hostLink:getSessionMeter', (event, protocol: unknown) => {
+  assertIpcSender(event, 'hostLink:getSessionMeter');
+  if (protocol !== 'meshtastic' && protocol !== 'meshcore') {
+    throw new Error('Invalid protocol');
+  }
+  return snapshotLiveSessionMeter(protocol);
+});
+
 ipcMain.handle('http:connect', async (event, host: unknown, tls: unknown) => {
   if (!validateIpcSender(event)) throw new Error('http:connect: unauthorized sender');
   validateHttpHost(host);