From d1c067709b56b1bb7533154510443d4bd012b0fe Mon Sep 17 00:00:00 2001
From: Celia Amador <camadorg@redhat.com>
Date: Thu, 6 Aug 2026 09:00:26 +0200
Subject: [PATCH] EDM-4987: Do not send wrong frame that causes the session
 logout

Made-with: Cursor
---
 libs/ui-components/src/hooks/terminalWsUtils.ts   |  9 ---------
 .../src/hooks/useAppConsoleWebSocket.ts           | 13 +++++--------
 libs/ui-components/src/hooks/useWebSocket.ts      | 15 +++++++++++++--
 3 files changed, 18 insertions(+), 19 deletions(-)
 delete mode 100644 libs/ui-components/src/hooks/terminalWsUtils.ts

diff --git a/libs/ui-components/src/hooks/terminalWsUtils.ts b/libs/ui-components/src/hooks/terminalWsUtils.ts
deleted file mode 100644
index 0e0b627aa..000000000
--- a/libs/ui-components/src/hooks/terminalWsUtils.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-/** Prefix WebSocket payload with a k8s-style channel byte (0x00 stdin, 0x04 resize). */
-export const msgToBytes = (msg: string, resize?: boolean) => {
-  const encoder = new TextEncoder();
-  const encodedData = encoder.encode(msg);
-  const result = new Uint8Array(encodedData.length + 1);
-  result[0] = resize ? 0x4 : 0x00;
-  result.set(encodedData, 1);
-  return result;
-};
diff --git a/libs/ui-components/src/hooks/useAppConsoleWebSocket.ts b/libs/ui-components/src/hooks/useAppConsoleWebSocket.ts
index 5c38ed40d..8a9c5de0a 100644
--- a/libs/ui-components/src/hooks/useAppConsoleWebSocket.ts
+++ b/libs/ui-components/src/hooks/useAppConsoleWebSocket.ts
@@ -1,6 +1,5 @@
 import * as React from 'react';
 import { useAppContext } from './useAppContext';
-import { msgToBytes } from './terminalWsUtils';
 
 const APP_CONSOLE_CLOSE_CODE = 1000;
 const APP_CONSOLE_CLOSE_REASON = 'client disconnect';
@@ -100,16 +99,14 @@ export const useAppConsoleWebSocket = (
   const forceConnectRef = React.useRef(false);
 
   const sendMessage = React.useCallback((data: string, resize?: boolean) => {
-    const ws = wsRef.current;
-    if (ws?.readyState !== WebSocket.OPEN) {
-      return;
-    }
-    // Serial stdin is raw bytes; resize uses device-console channel framing (0x4 + size JSON).
+    // App console uses raw serial websocket (raw bytes, not k8s channels). Resize is not supported
     if (resize) {
-      ws.send(msgToBytes(data, true));
       return;
     }
-    ws.send(new TextEncoder().encode(data));
+    const ws = wsRef.current;
+    if (ws?.readyState === WebSocket.OPEN) {
+      ws.send(new TextEncoder().encode(data));
+    }
   }, []);
 
   const disconnect = React.useCallback(() => {
diff --git a/libs/ui-components/src/hooks/useWebSocket.ts b/libs/ui-components/src/hooks/useWebSocket.ts
index f384cf35e..34faafb6e 100644
--- a/libs/ui-components/src/hooks/useWebSocket.ts
+++ b/libs/ui-components/src/hooks/useWebSocket.ts
@@ -1,10 +1,21 @@
 import * as React from 'react';
 import { useTranslation } from './useTranslation';
 import { useAppContext } from './useAppContext';
-import { msgToBytes } from './terminalWsUtils';
 
 const isErrorCloseEvent = (evt: CloseEvent) => evt.code !== 1000 && evt.code !== 1001;
 
+const k8sStreamChannel = 0x00;
+const k8sResizeChannel = 0x04;
+
+/** Device console uses k8s stream channels */
+const encodeK8sChannelFrame = (msg: string, resize?: boolean): Uint8Array<ArrayBuffer> => {
+  const encodedData = new TextEncoder().encode(msg);
+  const frame = new Uint8Array(new ArrayBuffer(encodedData.length + 1));
+  frame[0] = resize ? k8sResizeChannel : k8sStreamChannel;
+  frame.set(encodedData, 1);
+  return frame;
+};
+
 type WsMetadata = {
   tty: boolean;
   term: string;
@@ -42,7 +53,7 @@ export const useWebSocket = <T>(
   const sendMessage = React.useCallback((data: string, resize?: boolean) => {
     const ws = wsRef.current;
     if (ws?.readyState === WebSocket.OPEN) {
-      ws.send(msgToBytes(data, resize));
+      ws.send(encodeK8sChannelFrame(data, resize));
     }
   }, []);