net: websocket: Send CLOSE back to server when received one

When zephyr receives WS CLOSE, send it back to server and close
the TCP connection.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/lib/websocket/websocket.c

@@ -1104,6 +1104,10 @@ int websocket_recv_msg(int ws_sock, uint8_t *buf, size_t buf_len,
 		}
 	}
 
+	if (ctx->message_type == WEBSOCKET_FLAG_CLOSE) {
+		return websocket_internal_disconnect(ctx);
+	}
+
 	return payload.count;
 }