lnpeermgr: add_peer: fix check if proxy enabled

LNPeerManager.add_peer would only check if self.network.proxy is set,
which it is always as Network is initialized with self.proxy =
ProxySettings(). Instead it should check if proxy is set and enabled.

electrum/lnworker.py

@@ -588,7 +588,7 @@ class LNPeerManager(Logger, EventListener, NetworkRetryManager[LNPeerAddr]):
                     host, port, timestamp = self.choose_preferred_address(list(addrs))
             port = int(port)
 
-            if not self.network.proxy:
+            if not self.network.proxy or not self.network.proxy.enabled:
                 # Try DNS-resolving the host (if needed). This is simply so that
                 # the caller gets a nice exception if it cannot be resolved.
                 # (we don't do the DNS lookup if a proxy is set, to avoid a DNS-leak)

tests/test_lnpeer.py

@@ -26,7 +26,7 @@ from electrum import bitcoin
 from electrum import util
 from electrum import constants
 from electrum import bip32
-from electrum.network import Network
+from electrum.network import Network, ProxySettings
 from electrum import simple_config, lnutil
 from electrum.lnaddr import lnencode, LnAddr, lndecode
 from electrum.bitcoin import COIN, sha256
@@ -71,6 +71,7 @@ class MockNetwork:
         self.path_finder = LNPathFinder(self.channel_db)
         self.lngossip = MockLNGossip()
         self.tx_queue = asyncio.Queue()
+        self.proxy = ProxySettings()
         self._blockchain = MockBlockchain()
 
     def get_local_height(self):

tests/test_lnpeermgr.py

@@ -0,0 +1,60 @@
+import logging
+import os
+import socket
+import asyncio
+from unittest import mock
+
+from . import ElectrumTestCase
+
+from electrum.lntransport import ConnStringFormatError
+from electrum.logging import console_stderr_handler
+
+
+class TestLNPeerManager(ElectrumTestCase):
+    TESTNET = True
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        console_stderr_handler.setLevel(logging.DEBUG)
+
+    async def asyncSetUp(self):
+        lnwallet = self.create_mock_lnwallet(name='mock_lnwallet_anchors', has_anchors=True)
+        self.lnpeermgr = lnwallet.lnpeermgr
+        await super().asyncSetUp()
+
+    async def test_add_peer_conn_string_errors(self):
+        unknown_node_id = os.urandom(33)
+        peermgr = self.lnpeermgr
+        peermgr._add_peer = mock.Mock(side_effect=NotImplementedError)
+
+        # Trampoline enabled, unknown node (no address in trampolines)
+        channel_db = peermgr.network.channel_db
+        peermgr.network.channel_db = None
+        try:
+            with self.assertRaises(ConnStringFormatError) as cm:
+                await peermgr.add_peer(unknown_node_id.hex())
+            self.assertIn("Address unknown for node", str(cm.exception))
+        finally:
+            peermgr.network.channel_db = channel_db  # re-set channel db
+
+        # Trampoline disabled, unknown node (no address in channel_db)
+        with mock.patch.object(peermgr.network.channel_db, 'get_node_addresses', return_value=[]):
+            with self.assertRaises(ConnStringFormatError) as cm:
+                await peermgr.add_peer(unknown_node_id.hex())
+            self.assertIn("Don't know any addresses for node", str(cm.exception))
+
+        # .onion address, but no proxy configured
+        onion_conn_str = unknown_node_id.hex() + "@somewhere.onion:9735"
+        self.assertFalse(peermgr.network.proxy.enabled)
+        with self.assertRaises(ConnStringFormatError) as cm:
+            await peermgr.add_peer(onion_conn_str)
+        self.assertIn(".onion address, but no proxy configured", str(cm.exception))
+
+        # Hostname does not resolve (getaddrinfo failed)
+        bad_host_conn_str = unknown_node_id.hex() + "@badhost:9735"
+        loop = asyncio.get_running_loop()
+        with mock.patch.object(loop, 'getaddrinfo', side_effect=socket.gaierror):
+            with self.assertRaises(ConnStringFormatError) as cm:
+                await peermgr.add_peer(bad_host_conn_str)
+            self.assertIn("Hostname does not resolve", str(cm.exception))