Refactor guest WiFi device creation to use a sentinel MAC address fallback

Author: jokob-sk

front/plugins/fritzbox/fritzbox.py

@@ -166,16 +166,16 @@ def check_guest_wifi_status(fc, guest_service_num):
     return guest_info
 
 
-def create_guest_wifi_device(fc, host):
+def create_guest_wifi_device(fc):
     """
     Create a synthetic device entry for guest WiFi.
     Derives a deterministic fake MAC from the Fritz!Box hardware MAC address.
-    Falls back to the configured host string if the MAC cannot be retrieved.
+    Falls back to a fixed sentinel string if the MAC cannot be retrieved.
     Returns: Device dictionary
     """
     try:
         fritzbox_mac = fc.call_action('DeviceInfo:1', 'GetInfo').get('NewMACAddress', '')
-        guest_mac = string_to_fake_mac(normalize_mac(fritzbox_mac) if fritzbox_mac else host)
+        guest_mac = string_to_fake_mac(normalize_mac(fritzbox_mac) if fritzbox_mac else 'FRITZBOX_GUEST')
 
         device = {
             'mac_address': guest_mac,
@@ -224,7 +224,7 @@ def main():
     if report_guest:
         guest_status = check_guest_wifi_status(fc, guest_service)
         if guest_status['active']:
-            guest_device = create_guest_wifi_device(fc, host)
+            guest_device = create_guest_wifi_device(fc)
             if guest_device:
                 device_data.append(guest_device)
 

test/plugins/test_fritzbox.py

@@ -7,11 +7,12 @@
 created during tests.
 """
 
-import hashlib
 import sys
 import os
 from unittest.mock import patch, MagicMock
 
+from utils.crypto_utils import string_to_fake_mac
+
 import pytest
 
 # ---------------------------------------------------------------------------
@@ -59,19 +60,12 @@ def _make_host_entry(mac="AA:BB:CC:DD:EE:FF", ip="192.168.1.10",
 @pytest.fixture
 def mock_fritz_hosts():
     """
-    Patches fritzconnection.lib.fritzhosts in sys.modules so that
-    fritzbox.get_connected_devices() uses a controllable FritzHosts mock.
-    Yields the FritzHosts *instance* (what FritzHosts(fc) returns).
+    Patches fritzbox.FritzHosts so that get_connected_devices() uses a
+    controllable mock.  Yields the FritzHosts *instance* (what FritzHosts(fc)
+    returns).
     """
     hosts_instance = MagicMock()
-    fritz_hosts_module = MagicMock()
-    fritz_hosts_module.FritzHosts = MagicMock(return_value=hosts_instance)
-
-    with patch.dict("sys.modules", {
-        "fritzconnection": MagicMock(),
-        "fritzconnection.lib": MagicMock(),
-        "fritzconnection.lib.fritzhosts": fritz_hosts_module,
-    }):
+    with patch("fritzbox.FritzHosts", return_value=hosts_instance):
         yield hosts_instance
 
 
@@ -229,12 +223,15 @@ def test_returns_device_dict(self):
         assert device["active_status"] == "Active"
         assert device["interface_type"] == "Access Point"
         assert device["ip_address"] == ""
+        # MAC must match string_to_fake_mac output (fa:ce: prefix)
+        assert device["mac_address"].startswith("fa:ce:")
 
     def test_guest_mac_has_locally_administered_bit(self):
-        """First byte must be 0x02 — locally-administered, unicast."""
+        """The locally-administered bit (0x02) must be set in the first byte.
+        string_to_fake_mac uses the 'fa:ce:' prefix; 0xFA & 0x02 == 0x02."""
         device = fritzbox.create_guest_wifi_device(self._fc_with_mac("AA:BB:CC:DD:EE:FF"))
         first_byte = int(device["mac_address"].split(":")[0], 16)
-        assert first_byte == 0x02
+        assert first_byte & 0x02 != 0
 
     def test_guest_mac_format_is_valid(self):
         """MAC must be 6 colon-separated lowercase hex pairs."""
@@ -258,11 +255,11 @@ def test_different_fritzbox_macs_produce_different_guest_macs(self):
         assert mac_a != mac_b
 
     def test_no_fritzbox_mac_uses_fallback(self):
-        """When DeviceInfo returns no MAC, fall back to 02:00:00:00:00:01."""
+        """When DeviceInfo returns no MAC, fall back to a sentinel-derived MAC."""
         fc = MagicMock()
         fc.call_action.return_value = {"NewMACAddress": ""}
         device = fritzbox.create_guest_wifi_device(fc)
-        assert device["mac_address"] == "02:00:00:00:00:01"
+        assert device["mac_address"] == string_to_fake_mac("FRITZBOX_GUEST")
 
     def test_device_info_exception_returns_none(self):
         """If DeviceInfo call raises, create_guest_wifi_device must return None."""
@@ -274,12 +271,11 @@ def test_device_info_exception_returns_none(self):
     def test_known_mac_produces_known_guest_mac(self):
         """
         Regression anchor: for a fixed Fritz!Box MAC, the expected guest MAC
-        is precomputed here independently. If the hashing logic in
-        fritzbox.py changes, this test fails immediately.
+        is derived via string_to_fake_mac(normalize_mac(...)).  If the hashing
+        logic in fritzbox.py or string_to_fake_mac changes, this test fails.
         """
-        fritzbox_mac = "aa:bb:cc:dd:ee:ff"  # normalize_mac output of "AA:BB:CC:DD:EE:FF"
-        digest = hashlib.md5(f"GUEST:{fritzbox_mac}".encode()).digest()
-        expected = "02:" + ":".join(f"{b:02x}" for b in digest[:5])
+        fritzbox_mac = normalize_mac("AA:BB:CC:DD:EE:FF")
+        expected = string_to_fake_mac(fritzbox_mac)
 
         device = fritzbox.create_guest_wifi_device(self._fc_with_mac("AA:BB:CC:DD:EE:FF"))
         assert device["mac_address"] == expected
@@ -296,10 +292,8 @@ def test_successful_connection(self):
         fc_instance.modelname = "FRITZ!Box 7590"
         fc_instance.system_version = "7.57"
         fc_class = MagicMock(return_value=fc_instance)
-        fc_module = MagicMock()
-        fc_module.FritzConnection = fc_class
 
-        with patch.dict("sys.modules", {"fritzconnection": fc_module}):
+        with patch("fritzbox.FritzConnection", fc_class):
             result = fritzbox.get_fritzbox_connection("fritz.box", 49443, "admin", "pass", True)
 
         assert result is fc_instance
@@ -308,16 +302,13 @@ def test_successful_connection(self):
         )
 
     def test_import_error_returns_none(self):
-        with patch.dict("sys.modules", {"fritzconnection": None}):
+        with patch("fritzbox.FritzConnection", side_effect=ImportError("fritzconnection not found")):
             result = fritzbox.get_fritzbox_connection("fritz.box", 49443, "admin", "pass", True)
 
         assert result is None
 
     def test_connection_exception_returns_none(self):
-        fc_module = MagicMock()
-        fc_module.FritzConnection.side_effect = Exception("Connection refused")
-
-        with patch.dict("sys.modules", {"fritzconnection": fc_module}):
+        with patch("fritzbox.FritzConnection", side_effect=Exception("Connection refused")):
             result = fritzbox.get_fritzbox_connection("fritz.box", 49443, "admin", "pass", True)
 
         assert result is None