nixos-module/container/bird: add radv

nix/nixos-module/container/bird.nix

@@ -2,6 +2,13 @@
 
 let
   hostConf = config.site.hosts.${hostName};
+
+  gatewayNet =
+    let
+      m = builtins.match "(.+)-gw" hostName;
+    in if m == null
+       then null
+       else builtins.head m;
 in
 {
   services.bird2 = {
@@ -23,16 +30,27 @@ in
         scan time 10;
       }
 
-      # protocol radv {
-      #   interface "c3d2" {
-      #     min ra interval 10;
-      #     max ra interval 60;
-      #     prefix ::/64 {
-      #       preferred lifetime 20;
-      #       valid lifetime 60;
-      #     };
-      #   };
-      # }
+      ${lib.optionalString (gatewayNet != null) ''
+      protocol radv {
+        rdnss ${config.site.net.serv.hosts6.dn42.dnscache};
+
+        interface "${gatewayNet}" {
+          min ra interval 10;
+          max ra interval 60;
+
+          ${builtins.concatStringsSep "\n" (
+            map (subnet6: ''
+              prefix ::/64 {
+                preferred lifetime 20;
+                valid lifetime 60;
+              };
+            '') (builtins.attrValues config.site.net.${gatewayNet}.subnets6)
+          )}
+
+          dnssl "${config.site.net.${gatewayNet}.domainName}";
+        };
+      }
+      ''}
 
       protocol ospf v2 ZW4 {
         area 0 {