Support custom DNS configuration on auto

So far, when the network setting is set to auto, we don't allow a
custom DNS configuration. However, it is a perfectly valid use case to
provide custom DNS configuration while using automatic IP configuration
(e.g. DHCP). Especially when the DHCP server doesn't provide a DNS
server. In this case, systemd-resolved (at least on Home Assistant OS)
falls back to Cloudflare. This might not what the user wants. Customze
the DNS setting allows to set a custom fallback DNS server or override
a potential non-working DHCP provided one.

supervisor/api/network.py

@@ -29,6 +29,7 @@ from ..const import (
     ATTR_METHOD,
     ATTR_MODE,
     ATTR_NAMESERVERS,
+    ATTR_NAMESERVERS_AUTO,
     ATTR_PARENT,
     ATTR_PRIMARY,
     ATTR_PSK,
@@ -90,6 +91,7 @@ def ipconfig_struct(config: IpConfig) -> dict[str, Any]:
     return {
         ATTR_METHOD: config.method,
         ATTR_ADDRESS: [address.with_prefixlen for address in config.address],
+        ATTR_NAMESERVERS_AUTO: config.nameservers_auto,
         ATTR_NAMESERVERS: [str(address) for address in config.nameservers],
         ATTR_GATEWAY: str(config.gateway) if config.gateway else None,
         ATTR_READY: config.ready,
@@ -200,15 +202,19 @@ class APINetwork(CoreSysAttributes):
             if key == ATTR_IPV4:
                 interface.ipv4 = replace(
                     interface.ipv4
-                    or IpConfig(InterfaceMethod.STATIC, [], None, [], None),
+                    or IpConfig(InterfaceMethod.STATIC, [], None, False, [], None),
                     **config,
                 )
+                if interface.ipv4.method == InterfaceMethod.AUTO:
+                    interface.ipv4.nameservers_auto = ATTR_NAMESERVERS not in config
             elif key == ATTR_IPV6:
                 interface.ipv6 = replace(
                     interface.ipv6
-                    or IpConfig(InterfaceMethod.STATIC, [], None, [], None),
+                    or IpConfig(InterfaceMethod.STATIC, [], None, False, [], None),
                     **config,
                 )
+                if interface.ipv6.method == InterfaceMethod.AUTO:
+                    interface.ipv6.nameservers_auto = ATTR_NAMESERVERS not in config
             elif key == ATTR_WIFI:
                 interface.wifi = replace(
                     interface.wifi

supervisor/const.py

@@ -244,6 +244,7 @@ ATTR_MODE = "mode"
 ATTR_MULTICAST = "multicast"
 ATTR_NAME = "name"
 ATTR_NAMESERVERS = "nameservers"
+ATTR_NAMESERVERS_AUTO = "nameservers_auto"
 ATTR_NETWORK = "network"
 ATTR_NETWORK_DESCRIPTION = "network_description"
 ATTR_NETWORK_RX = "network_rx"

supervisor/dbus/network/configuration.py

@@ -64,6 +64,7 @@ class IpProperties:
     """IP properties object for Network Manager."""
 
     method: str | None
+    dns: list[str] | None
 
 
 @dataclass(slots=True)

supervisor/dbus/network/setting/__init__.py

@@ -6,7 +6,7 @@ from typing import Any
 from dbus_fast import Variant
 from dbus_fast.aio.message_bus import MessageBus
 
-from ....const import ATTR_METHOD, ATTR_MODE, ATTR_PSK, ATTR_SSID
+from ....const import ATTR_DNS, ATTR_METHOD, ATTR_MODE, ATTR_PSK, ATTR_SSID
 from ...const import DBUS_NAME_NM
 from ...interface import DBusInterface
 from ...utils import dbus_connected
@@ -75,7 +75,7 @@ def _merge_settings_attribute(
 class NetworkSetting(DBusInterface):
     """Network connection setting object for Network Manager.
 
-    https://developer.gnome.org/NetworkManager/stable/gdbus-org.freedesktop.NetworkManager.Settings.Connection.html
+    https://networkmanager.dev/docs/api/1.48.0/gdbus-org.freedesktop.NetworkManager.Settings.Connection.html
     """
 
     bus_name: str = DBUS_NAME_NM
@@ -229,11 +229,13 @@ class NetworkSetting(DBusInterface):
         if CONF_ATTR_IPV4 in data:
             self._ipv4 = IpProperties(
                 data[CONF_ATTR_IPV4].get(ATTR_METHOD),
+                data[CONF_ATTR_IPV4].get(ATTR_DNS),
             )
 
         if CONF_ATTR_IPV6 in data:
             self._ipv6 = IpProperties(
                 data[CONF_ATTR_IPV6].get(ATTR_METHOD),
+                data[CONF_ATTR_IPV6].get(ATTR_DNS),
             )
 
         if CONF_ATTR_MATCH in data:

supervisor/dbus/network/setting/generate.py

@@ -76,13 +76,6 @@ def get_connection_from_interface(
         ipv4["method"] = Variant("s", "disabled")
     else:
         ipv4["method"] = Variant("s", "manual")
-        ipv4["dns"] = Variant(
-            "au",
-            [
-                socket.htonl(int(ip_address))
-                for ip_address in interface.ipv4.nameservers
-            ],
-        )
 
         adressdata = []
         for address in interface.ipv4.address:
@@ -96,6 +89,18 @@ def get_connection_from_interface(
         ipv4["address-data"] = Variant("aa{sv}", adressdata)
         ipv4["gateway"] = Variant("s", str(interface.ipv4.gateway))
 
+    if (
+        interface.ipv4.method == InterfaceMethod.AUTO
+        and not interface.ipv4.nameservers_auto
+    ) or interface.ipv4.method == InterfaceMethod.STATIC:
+        ipv4["dns"] = Variant(
+            "au",
+            [
+                socket.htonl(int(ip_address))
+                for ip_address in interface.ipv4.nameservers
+            ],
+        )
+
     conn[CONF_ATTR_IPV4] = ipv4
 
     ipv6 = {}
@@ -105,9 +110,6 @@ def get_connection_from_interface(
         ipv6["method"] = Variant("s", "link-local")
     else:
         ipv6["method"] = Variant("s", "manual")
-        ipv6["dns"] = Variant(
-            "aay", [ip_address.packed for ip_address in interface.ipv6.nameservers]
-        )
 
         adressdata = []
         for address in interface.ipv6.address:
@@ -121,6 +123,14 @@ def get_connection_from_interface(
         ipv6["address-data"] = Variant("aa{sv}", adressdata)
         ipv6["gateway"] = Variant("s", str(interface.ipv6.gateway))
 
+    if (
+        interface.ipv6.method == InterfaceMethod.AUTO
+        and not interface.ipv6.nameservers_auto
+    ) or interface.ipv6.method == InterfaceMethod.STATIC:
+        ipv6["dns"] = Variant(
+            "aay", [ip_address.packed for ip_address in interface.ipv6.nameservers]
+        )
+
     conn[CONF_ATTR_IPV6] = ipv6
 
     if interface.type == InterfaceType.ETHERNET:

supervisor/host/configuration.py

@@ -2,6 +2,7 @@
 
 from dataclasses import dataclass
 from ipaddress import IPv4Address, IPv4Interface, IPv6Address, IPv6Interface
+import socket
 
 from ..dbus.const import (
     ConnectionStateFlags,
@@ -32,6 +33,7 @@ class IpConfig:
     method: InterfaceMethod
     address: list[IPv4Interface | IPv6Interface]
     gateway: IPv4Address | IPv6Address | None
+    nameservers_auto: bool
     nameservers: list[IPv4Address | IPv6Address]
     ready: bool | None
 
@@ -102,6 +104,30 @@ class Interface:
             bool(inet.connection)
             and ConnectionStateFlags.IP6_READY in inet.connection.state_flags
         )
+
+        # Use Nameserver from configuration if present (means manual DNS override)
+        if inet.settings.ipv4.dns:
+            ipv4_nameservers_auto = False
+            ipv4_nameservers = [
+                IPv4Address(socket.ntohl(ip)) for ip in inet.settings.ipv4.dns
+            ]
+        elif inet.connection.ipv4.nameservers:
+            ipv4_nameservers_auto = True
+            ipv4_nameservers = inet.connection.ipv4.nameservers
+        else:
+            ipv4_nameservers_auto = True
+            ipv4_nameservers = []
+
+        if inet.settings.ipv6.dns:
+            ipv6_nameservers_auto = False
+            ipv6_nameservers = [IPv6Address(bytes(ip)) for ip in inet.settings.ipv6.dns]
+        elif inet.connection.ipv6.nameservers:
+            ipv6_nameservers_auto = True
+            ipv6_nameservers = inet.connection.ipv6.nameservers
+        else:
+            ipv6_nameservers_auto = True
+            ipv6_nameservers = []
+
         return Interface(
             inet.name,
             inet.hw_address,
@@ -111,27 +137,29 @@ class Interface:
             inet.primary,
             Interface._map_nm_type(inet.type),
             IpConfig(
-                ipv4_method,
+                method=ipv4_method,
-                inet.connection.ipv4.address if inet.connection.ipv4.address else [],
+                address=inet.connection.ipv4.address
-                inet.connection.ipv4.gateway,
+                if inet.connection.ipv4.address
-                inet.connection.ipv4.nameservers
-                if inet.connection.ipv4.nameservers
                 else [],
-                ipv4_ready,
+                gateway=inet.connection.ipv4.gateway,
+                nameservers_auto=ipv4_nameservers_auto,
+                nameservers=ipv4_nameservers,
+                ready=ipv4_ready,
             )
             if inet.connection and inet.connection.ipv4
-            else IpConfig(ipv4_method, [], None, [], ipv4_ready),
+            else IpConfig(ipv4_method, [], None, True, [], ipv4_ready),
             IpConfig(
-                ipv6_method,
+                method=ipv6_method,
-                inet.connection.ipv6.address if inet.connection.ipv6.address else [],
+                address=inet.connection.ipv6.address
-                inet.connection.ipv6.gateway,
+                if inet.connection.ipv6.address
-                inet.connection.ipv6.nameservers
-                if inet.connection.ipv6.nameservers
                 else [],
-                ipv6_ready,
+                gateway=inet.connection.ipv6.gateway,
+                nameservers_auto=ipv6_nameservers_auto,
+                nameservers=ipv6_nameservers,
+                ready=ipv6_ready,
             )
             if inet.connection and inet.connection.ipv6
-            else IpConfig(ipv6_method, [], None, [], ipv6_ready),
+            else IpConfig(ipv6_method, [], None, True, [], ipv6_ready),
             Interface._map_nm_wifi(inet),
             Interface._map_nm_vlan(inet),
         )