nixos/networkd: DHCPv6PrefixDelegation -> DHCPPrefixDelegation

Adapt to changes introduced in Systemd 250:

> The [DHCPv6PrefixDelegation] section in .network file is renamed to
> [DHCPPrefixDelegation], as now the prefix delegation is also
> supported with DHCPv4 protocol by enabling the Use6RD= setting.

Replaces the `dhcpV6PrefixDelegationConfig` with
`dhcpPrefixDelegationConfig` and throws an error if the old option is
used.

Also adapt the respective IPv6 prefix delegation test.

nixos/modules/system/boot/networkd.nix

@@ -526,7 +526,7 @@ let
           "IPv6ProxyNDP"
           "IPv6ProxyNDPAddress"
           "IPv6SendRA"
-          "DHCPv6PrefixDelegation"
+          "DHCPPrefixDelegation"
           "IPv6MTUBytes"
           "Bridge"
           "Bond"
@@ -569,7 +569,7 @@ let
         (assertValueOneOf "IPv4ProxyARP" boolValues)
         (assertValueOneOf "IPv6ProxyNDP" boolValues)
         (assertValueOneOf "IPv6SendRA" boolValues)
-        (assertValueOneOf "DHCPv6PrefixDelegation" boolValues)
+        (assertValueOneOf "DHCPPrefixDelegation" boolValues)
         (assertByteFormat "IPv6MTUBytes")
         (assertValueOneOf "ActiveSlave" boolValues)
         (assertValueOneOf "PrimarySlave" boolValues)
@@ -766,15 +766,20 @@ let
         (assertInt "IAID")
       ];
 
-      sectionDHCPv6PrefixDelegation = checkUnitConfig "DHCPv6PrefixDelegation" [
+      sectionDHCPPrefixDelegation = checkUnitConfig "DHCPPrefixDelegation" [
         (assertOnlyFields [
+          "UplinkInterface"
           "SubnetId"
           "Announce"
           "Assign"
           "Token"
+          "ManageTemporaryAddress"
+          "RouteMetric"
         ])
         (assertValueOneOf "Announce" boolValues)
         (assertValueOneOf "Assign" boolValues)
+        (assertValueOneOf "ManageTemporaryAddress" boolValues)
+        (assertRange "RouteMetric" 0 4294967295)
       ];
 
       sectionIPv6AcceptRA = checkUnitConfig "IPv6AcceptRA" [
@@ -1338,12 +1343,17 @@ let
     };
 
     dhcpV6PrefixDelegationConfig = mkOption {
+      visible = false;
+      apply = _: throw "The option `systemd.network.networks.<name>.dhcpV6PrefixDelegationConfig` has been renamed to `systemd.network.networks.<name>.dhcpPrefixDelegationConfig`.";
+    };
+
+    dhcpPrefixDelegationConfig = mkOption {
       default = {};
       example = { SubnetId = "auto"; Announce = true; };
-      type = types.addCheck (types.attrsOf unitOption) check.network.sectionDHCPv6PrefixDelegation;
+      type = types.addCheck (types.attrsOf unitOption) check.network.sectionDHCPPrefixDelegation;
       description = lib.mdDoc ''
         Each attribute in this set specifies an option in the
-        `[DHCPv6PrefixDelegation]` section of the unit. See
+        `[DHCPPrefixDelegation]` section of the unit. See
         {manpage}`systemd.network(5)` for details.
       '';
     };
@@ -1789,9 +1799,9 @@ let
           [DHCPv6]
           ${attrsToSection def.dhcpV6Config}
         ''
-        + optionalString (def.dhcpV6PrefixDelegationConfig != { }) ''
-          [DHCPv6PrefixDelegation]
-          ${attrsToSection def.dhcpV6PrefixDelegationConfig}
+        + optionalString (def.dhcpPrefixDelegationConfig != { }) ''
+          [DHCPPrefixDelegation]
+          ${attrsToSection def.dhcpPrefixDelegationConfig}
         ''
         + optionalString (def.ipv6AcceptRAConfig != { }) ''
           [IPv6AcceptRA]

nixos/tests/systemd-networkd-ipv6-prefix-delegation.nix

@@ -176,7 +176,7 @@ import ./make-test-python.nix ({pkgs, ...}: {
               IPv6AcceptRA = false;
 
               # Delegate prefixes from the DHCPv6 PD pool.
-              DHCPv6PrefixDelegation = true;
+              DHCPPrefixDelegation = true;
               IPv6SendRA = true;
             };