Improve WiFi settings error handling (#5293)

* Improve WiFi settings error handling

Currently, the frontend potentially provides no WiFi settings dictionary
but still tries to update other (IP address) settings on the interface.
This leads to a stack trace since network manager is not able to fetch
the WiFi settings from the settings dictionary. Simply fill out what
we can and let NetworkManager provide an error.

Also allow to disable a network interface which has no configuration.
This avoids an error when switching to auto and back to disabled then
press save on a new wireless network interface.

* Add debug message when already disabled

* Add pytest for incomplete WiFi settings as psoted by frontend

Simulate the frontend posting no WiFi settings. Make sure the Supervisor
handles this gracefully.

supervisor/dbus/network/setting/generate.py

@@ -199,15 +199,17 @@ def get_connection_from_interface(
     elif interface.type == InterfaceType.WIRELESS:
         wireless = {
             CONF_ATTR_802_WIRELESS_ASSIGNED_MAC: Variant("s", "preserve"),
-            CONF_ATTR_802_WIRELESS_SSID: Variant(
-                "ay", interface.wifi.ssid.encode("UTF-8")
-            ),
             CONF_ATTR_802_WIRELESS_MODE: Variant("s", "infrastructure"),
             CONF_ATTR_802_WIRELESS_POWERSAVE: Variant("i", 1),
         }
+        if interface.wifi and interface.wifi.ssid:
+            wireless[CONF_ATTR_802_WIRELESS_SSID] = Variant(
+                "ay", interface.wifi.ssid.encode("UTF-8")
+            )
+
         conn[CONF_ATTR_802_WIRELESS] = wireless
 
-        if interface.wifi.auth != "open":
+        if interface.wifi and interface.wifi.auth != "open":
             wireless["security"] = Variant("s", CONF_ATTR_802_WIRELESS_SECURITY)
             wireless_security = {}
             if interface.wifi.auth == "wep":

supervisor/host/network.py

@@ -236,7 +236,10 @@ async def apply_changes(
                 ) from err
 
         # Remove config from interface
-        elif inet and inet.settings and not interface.enabled:
+        elif inet and not interface.enabled:
+            if not inet.settings:
+                _LOGGER.debug("Interface %s is already disabled.", interface.name)
+                return
             try:
                 await inet.settings.delete()
             except DBusError as err:

tests/api/test_network.py

@@ -234,7 +234,7 @@ async def test_api_network_interface_update_ethernet(
 
 
 async def test_api_network_interface_update_wifi(api_client: TestClient):
-    """Test network manager api."""
+    """Test network interface WiFi API."""
     resp = await api_client.post(
         f"/network/interface/{TEST_INTERFACE_WLAN_NAME}/update",
         json={
@@ -252,6 +252,30 @@ async def test_api_network_interface_update_wifi(api_client: TestClient):
     assert result["result"] == "ok"
 
 
+async def test_api_network_interface_update_wifi_error(api_client: TestClient):
+    """Test network interface WiFi API error handling."""
+    # Simulate frontend WiFi interface edit where the user did not select
+    # a WiFi SSID.
+    resp = await api_client.post(
+        f"/network/interface/{TEST_INTERFACE_WLAN_NAME}/update",
+        json={
+            "enabled": True,
+            "ipv4": {
+                "method": "auto",
+            },
+            "ipv6": {
+                "method": "auto",
+            },
+        },
+    )
+    result = await resp.json()
+    assert result["result"] == "error"
+    assert (
+        result["message"]
+        == "Can't create config and activate wlan0: A 'wireless' setting with a valid SSID is required if no AP path was given."
+    )
+
+
 async def test_api_network_interface_update_remove(api_client: TestClient):
     """Test network manager api."""
     resp = await api_client.post(

tests/dbus_service_mocks/network_manager.py

@@ -1,5 +1,6 @@
 """Mock of Network Manager service."""
 
+from dbus_fast import DBusError
 from dbus_fast.service import PropertyAccess, dbus_property, signal
 
 from .base import DBusServiceMock, dbus_method
@@ -227,6 +228,18 @@ def AddAndActivateConnection(
         self, connection: "a{sa{sv}}", device: "o", speciic_object: "o"
     ) -> "oo":
         """Do AddAndActivateConnection method."""
+        if connection["connection"]["type"].value == "802-11-wireless":
+            if "802-11-wireless" not in connection:
+                raise DBusError(
+                    "org.freedesktop.NetworkManager.Device.InvalidConnection",
+                    "A 'wireless' setting is required if no AP path was given.",
+                )
+            if "ssid" not in connection["802-11-wireless"]:
+                raise DBusError(
+                    "org.freedesktop.NetworkManager.Device.InvalidConnection",
+                    "A 'wireless' setting with a valid SSID is required if no AP path was given.",
+                )
+
         return [
             "/org/freedesktop/NetworkManager/Settings/1",
             "/org/freedesktop/NetworkManager/ActiveConnection/1",