trezor: move the transport-related reimplemented parts into a separate module. disable the bridge transport.

The bridge transport uses requests.post, which uses socket.getaddrinfo under the hood, which on some OSes (MacOS, Windows) in CPython takes a lock. The enumerate method for the bridge transport can block for 10-30 seconds while waiting for this lock.

plugins/trezor/transport.py

@@ -0,0 +1,95 @@
+from electrum.util import PrintError
+
+
+class TrezorTransport(PrintError):
+
+    @staticmethod
+    def all_transports():
+        """Reimplemented trezorlib.transport.all_transports so that we can
+        enable/disable specific transports.
+        """
+        try:
+            # only to detect trezorlib version
+            from trezorlib.transport import all_transports
+        except ImportError:
+            # old trezorlib. compat for trezorlib < 0.9.2
+            transports = []
+            #try:
+            #    from trezorlib.transport_bridge import BridgeTransport
+            #    transports.append(BridgeTransport)
+            #except BaseException:
+            #    pass
+            try:
+                from trezorlib.transport_hid import HidTransport
+                transports.append(HidTransport)
+            except BaseException:
+                pass
+            try:
+                from trezorlib.transport_udp import UdpTransport
+                transports.append(UdpTransport)
+            except BaseException:
+                pass
+            try:
+                from trezorlib.transport_webusb import WebUsbTransport
+                transports.append(WebUsbTransport)
+            except BaseException:
+                pass
+        else:
+            # new trezorlib.
+            transports = []
+            #try:
+            #    from trezorlib.transport.bridge import BridgeTransport
+            #    transports.append(BridgeTransport)
+            #except BaseException:
+            #    pass
+            try:
+                from trezorlib.transport.hid import HidTransport
+                transports.append(HidTransport)
+            except BaseException:
+                pass
+            try:
+                from trezorlib.transport.udp import UdpTransport
+                transports.append(UdpTransport)
+            except BaseException:
+                pass
+            try:
+                from trezorlib.transport.webusb import WebUsbTransport
+                transports.append(WebUsbTransport)
+            except BaseException:
+                pass
+            return transports
+        return transports
+
+    def enumerate_devices(self):
+        """Just like trezorlib.transport.enumerate_devices,
+        but with exception catching, so that transports can fail separately.
+        """
+        devices = []
+        for transport in self.all_transports():
+            try:
+                new_devices = transport.enumerate()
+            except BaseException as e:
+                self.print_error('enumerate failed for {}. error {}'
+                                 .format(transport.__name__, str(e)))
+            else:
+                devices.extend(new_devices)
+        return devices
+
+    def get_transport(self, path=None):
+        """Reimplemented trezorlib.transport.get_transport,
+        (1) for old trezorlib
+        (2) to be able to disable specific transports
+        (3) to call our own enumerate_devices that catches exceptions
+        """
+        if path is None:
+            try:
+                return self.enumerate_devices()[0]
+            except IndexError:
+                raise Exception("No TREZOR device found") from None
+
+        def match_prefix(a, b):
+            return a.startswith(b) or b.startswith(a)
+        transports = [t for t in self.all_transports() if match_prefix(path, t.PATH_PREFIX)]
+        if transports:
+            return transports[0].find_by_path(path)
+        raise Exception("Unknown path prefix '%s'" % path)

plugins/trezor/trezor.py

@@ -117,6 +117,7 @@ class TrezorPlugin(HW_PluginBase):
             return
 
         from . import client
+        from . import transport
         import trezorlib.ckd_public
         import trezorlib.messages
         self.client_class = client.TrezorClient
@@ -124,88 +125,17 @@ class TrezorPlugin(HW_PluginBase):
         self.types = trezorlib.messages
         self.DEVICE_IDS = ('TREZOR',)
 
+        self.transport_handler = transport.TrezorTransport()
         self.device_manager().register_enumerate_func(self.enumerate)
 
-    @staticmethod
-    def _all_transports():
-        """Reimplemented trezorlib.transport.all_transports for old trezorlib.
-        Remove this when we start to require trezorlib 0.9.2
-        """
-        try:
-            from trezorlib.transport import all_transports
-        except ImportError:
-            # compat for trezorlib < 0.9.2
-            def all_transports():
-                transports = []
-                try:
-                    from trezorlib.transport_bridge import BridgeTransport
-                    transports.append(BridgeTransport)
-                except BaseException:
-                    pass
-                try:
-                    from trezorlib.transport_hid import HidTransport
-                    transports.append(HidTransport)
-                except BaseException:
-                    pass
-                try:
-                    from trezorlib.transport_udp import UdpTransport
-                    transports.append(UdpTransport)
-                except BaseException:
-                    pass
-                try:
-                    from trezorlib.transport_webusb import WebUsbTransport
-                    transports.append(WebUsbTransport)
-                except BaseException:
-                    pass
-                return transports
-        return all_transports()
-
-    def _enumerate_devices(self):
-        """Just like trezorlib.transport.enumerate_devices,
-        but with exception catching, so that transports can fail separately.
-        """
-        devices = []
-        for transport in self._all_transports():
-            try:
-                new_devices = transport.enumerate()
-            except BaseException as e:
-                self.print_error('enumerate failed for {}. error {}'
-                                 .format(transport.__name__, str(e)))
-            else:
-                devices.extend(new_devices)
-        return devices
-
     def enumerate(self):
-        devices = self._enumerate_devices()
+        devices = self.transport_handler.enumerate_devices()
         return [Device(d.get_path(), -1, d.get_path(), 'TREZOR', 0) for d in devices]
 
-    def _get_transport(self, path=None):
-        """Reimplemented trezorlib.transport.get_transport for old trezorlib.
-        Remove this when we start to require trezorlib 0.9.2
-        """
-        try:
-            from trezorlib.transport import get_transport
-        except ImportError:
-            # compat for trezorlib < 0.9.2
-            def get_transport(path=None, prefix_search=False):
-                if path is None:
-                    try:
-                        return self._enumerate_devices()[0]
-                    except IndexError:
-                        raise Exception("No TREZOR device found") from None
-
-                def match_prefix(a, b):
-                    return a.startswith(b) or b.startswith(a)
-                transports = [t for t in self._all_transports() if match_prefix(path, t.PATH_PREFIX)]
-                if transports:
-                    return transports[0].find_by_path(path)
-                raise Exception("Unknown path prefix '%s'" % path)
-        return get_transport(path)
-
     def create_client(self, device, handler):
         try:
             self.print_error("connecting to device at", device.path)
-            transport = self._get_transport(device.path)
+            transport = self.transport_handler.get_transport(device.path)
         except BaseException as e:
             self.print_error("cannot connect at", device.path, str(e))
             return None