Use builtin IPv6 RA support in systemd-networkd

Author: jmbaur

lan.nix

@@ -13,12 +13,32 @@ in
       networkConfig = {
         DHCPPrefixDelegation = true;
         IPv6AcceptRA = false;
+        IPv6SendRA = true;
         IgnoreCarrierLoss = true;
         MulticastDNS = true;
-        Address = [
-          cfg.routerIpv6Ula.cidr
-        ] ++ lib.optional (cfg.ipv6GuaPrefix != null) cfg.routerIpv6Gua.cidr;
       };
+      ipv6SendRAConfig = {
+        EmitDNS = true;
+        DNS = "_link_local";
+      };
+      ipv6Prefixes =
+        [
+          {
+            Prefix = cfg.ipv6UlaPrefix;
+            Assign = true;
+          }
+        ]
+        ++ lib.optionals (cfg.ipv6GuaPrefix != null) [
+          {
+            Prefix = cfg.ipv6GuaPrefix;
+            Assign = true;
+          }
+        ];
+      # TODO(jared): make nixos option
+      extraConfig = ''
+        [IPv6PREF64Prefix]
+        Prefix=${config.networking.jool.nat64.default.global.pool6}
+      '';
     };
   };
 }

module.nix

@@ -6,7 +6,6 @@
     ./hostapd.nix
     ./lan.nix
     ./options.nix
-    ./ra.nix
     ./wan.nix
   ];
 

options.nix

@@ -7,9 +7,6 @@ let
   hasStaticGua = cfg.ipv6GuaPrefix != null;
   guaNetwork = _lib.parseIpv6Network cfg.ipv6GuaPrefix;
   ulaNetwork = _lib.parseIpv6Network cfg.ipv6UlaPrefix;
-
-  mkIpv6GuaAddress = _lib.mkIpv6Address guaNetwork.hextets;
-  mkIpv6UlaAddress = _lib.mkIpv6Address ulaNetwork.hextets;
 in
 {
   options.router = with lib; {
@@ -88,30 +85,6 @@ in
         The 64-bit IPv6 GUA network prefix (in CIDR notation).
       '';
     };
-    routerIpv6Gua = mkOption {
-      internal = true;
-      readOnly = true;
-      default =
-        let
-          address = mkIpv6GuaAddress [
-            0
-            0
-            0
-            0
-            0
-            0
-            0
-            1
-          ];
-        in
-        if hasStaticGua then
-          {
-            inherit address;
-            cidr = "${address}/${toString guaNetwork.prefixLength}";
-          }
-        else
-          null;
-    };
     ipv6UlaPrefix = mkOption {
       type = types.str;
       example = "fd38:5f81:b15d::/64";
@@ -120,27 +93,6 @@ in
         a ULA prefix at https://www.ip-six.de/index.php.
       '';
     };
-    routerIpv6Ula = mkOption {
-      internal = true;
-      readOnly = true;
-      default =
-        let
-          address = mkIpv6UlaAddress [
-            0
-            0
-            0
-            0
-            0
-            0
-            0
-            1
-          ];
-        in
-        {
-          inherit address;
-          cidr = "${address}/${toString ulaNetwork.prefixLength}";
-        };
-    };
     dns = {
       upstreamProvider = mkOption {
         type = types.enum [

ra.nix

@@ -37,10 +37,15 @@ nixosTest {
     };
 
   testScript = ''
-    router.wait_for_unit("systemd-networkd.service")
-    host1.wait_for_unit("multi-user.target")
+    router.wait_for_unit("network-online.target")
+    host1.wait_for_unit("network-online.target")
 
-    router.wait_until_succeeds("ping -c5 host1.local.")
-    host1.wait_until_succeeds("ping -c5 router.local.")
+    print(router.succeed("networkctl status eth1"))
+    print(router.succeed("resolvectl"))
+    print(host1.succeed("networkctl status eth1"))
+    print(host1.succeed("resolvectl"))
+
+    router.wait_until_succeeds("ping -c3 host1.local.")
+    host1.wait_until_succeeds("ping -c3 router.local.")
   '';
 }