network: async tor probe

electrum/gui/qml/qenetwork.py

@@ -86,6 +86,10 @@ class QENetwork(QObject, QtEventListener):
         self.proxySet.emit()
         self.proxyTorChanged.emit()
 
+    @event_listener
+    def on_event_tor_probed(self, *args):
+        self.proxyTorChanged.emit()
+
     def _update_status(self):
         server = str(self.network.get_parameters().server)
         if self._server != server:

electrum/gui/qt/main_window.py

@@ -496,6 +496,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
     def on_event_cert_mismatch(self, *args):
         self.show_cert_mismatch_error()
 
+    @qt_event_listener
+    def on_event_tor_probed(self, is_tor):
+        self.tor_button.setVisible(is_tor)
+
+    @qt_event_listener
+    def on_event_proxy_set(self, *args):
+        self.tor_button.setVisible(False)
+
     def close_wallet(self):
         if self.wallet:
             self.logger.info(f'close_wallet {self.wallet.storage.path}')
@@ -956,6 +964,9 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
         network_text = ""
         balance_text = ""
 
+        if self.tor_button:
+            self.tor_button.setVisible(self.network and self.network.tor_proxy)
+
         if self.network is None:
             network_text = _("Offline")
             icon = read_QIcon("status_disconnected.png")
@@ -1634,9 +1645,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
         sb.addPermanentWidget(self.lightning_button)
         self.update_lightning_icon()
         self.status_button = None
+        self.tor_button = None
         if self.network:
             self.status_button = StatusBarButton(read_QIcon("status_disconnected.png"), _("Network"), self.gui_object.show_network_dialog, sb_height)
             sb.addPermanentWidget(self.status_button)
+            self.tor_button = StatusBarButton(read_QIcon("tor_logo.png"), _("TOR"),
+                                                 self.gui_object.show_network_dialog, sb_height)
+            sb.addPermanentWidget(self.tor_button)
+            self.tor_button.setVisible(False)
         run_hook('create_status_bar', sb)
         self.setStatusBar(sb)
 

electrum/network.py

@@ -323,6 +323,8 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
 
         self._allowed_protocols = {PREFERRED_NETWORK_PROTOCOL}
 
+        self.proxy = None
+        self.tor_proxy = False
         self._init_parameters_from_config()
 
         self.taskgroup = None
@@ -510,6 +512,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
                                  oneserver=self.oneserver)
 
     def _init_parameters_from_config(self) -> None:
+        dns_hacks.configure_dns_resolver()
         self.auto_connect = self.config.NETWORK_AUTO_CONNECT
         self._set_default_server()
         self._set_proxy(deserialize_proxy(self.config.NETWORK_PROXY, self.config.NETWORK_PROXY_USER,
@@ -625,18 +628,29 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
         assert isinstance(self.default_server, ServerAddr), f"invalid type for default_server: {self.default_server!r}"
 
     def _set_proxy(self, proxy: Optional[dict]):
-        self.proxy = proxy
-        dns_hacks.configure_dns_resolver()
+        if self.proxy == proxy:
+            return
+
         self.logger.info(f'setting proxy {proxy}')
-
+        self.proxy = proxy
         self.tor_proxy = False
-        if bool(proxy) and proxy['mode'] == 'socks5':
-            # test for Tor
-            self.tor_proxy = util.is_tor_socks_port(proxy['host'], int(proxy['port']))
-            if self.tor_proxy:
-                self.logger.info(f'Proxy is TOR')
 
-        util.trigger_callback('proxy_set', self.proxy, self.tor_proxy)
+        def tor_probe_task(p):
+            assert p is not None
+            tor_proxy = util.is_tor_socks_port(p['host'], int(p['port']))
+            if self.proxy == p:  # is this the proxy we probed?
+                self.logger.info(f'Proxy is {"" if tor_proxy else "not "}TOR')
+                self._tor_probe_done(tor_proxy)
+
+        if proxy['mode'] == 'socks5':
+            t = threading.Thread(target=tor_probe_task, args=(proxy,), daemon=True)
+            t.start()
+
+        util.trigger_callback('proxy_set', self.proxy)
+
+    def _tor_probe_done(self, is_tor: bool):
+        self.tor_proxy = is_tor
+        util.trigger_callback('tor_probed', is_tor)
 
     @log_exceptions
     async def set_parameters(self, net_params: NetworkParameters):

electrum/util.py

@@ -1498,9 +1498,7 @@ def detect_tor_socks_proxy() -> Optional[Tuple[str, int]]:
 
 def is_tor_socks_port(host: str, port: int) -> bool:
     try:
-        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
-            s.settimeout(1.0)
-            s.connect((host, port))
+        with socket.create_connection((host, port), timeout=10) as s:
             # mimic "tor-resolve 0.0.0.0".
             # see https://github.com/spesmilo/electrum/issues/7317#issuecomment-1369281075
             # > this is a socks5 handshake, followed by a socks RESOLVE request as defined in