use bind for local dns

hosts/swan/default.nix

@@ -53,6 +53,7 @@ inputs.nixpkgs.lib.nixosSystem {
       dotfiles.enable = true;
       arrs.enable = true;
 
+      services.bind.enable = true;
       services.caddy.enable = true;
       services.jellyfin.enable = true;
       services.nextcloud.enable = true;

modules/nixos/hardware/networking.nix

@@ -10,6 +10,9 @@
     services.avahi = {
       enable = true;
       domainName = "local";
+      ipv6 = false; # Should work either way
+      # Resolve local hostnames using Avahi DNS
+      nssmdns = true;
       publish = {
         enable = true;
         addresses = true;
@@ -17,10 +20,6 @@
         workstation = true;
       };
     };
-
-    # Resolve local hostnames using Avahi DNS
-    services.avahi.nssmdns = true;
-
   };
 
 }

modules/nixos/services/bind.nix

@@ -0,0 +1,55 @@
+{ config, pkgs, lib, ... }:
+
+let
+
+  localIp = "192.168.1.218";
+  localServices = [
+    config.hostnames.stream
+    config.hostnames.content
+    config.hostnames.books
+    config.hostnames.download
+  ];
+  mkRecord = service: "${service}       A       ${localIp}";
+  localRecords = lib.concatLines (map mkRecord localServices);
+
+in {
+
+  config = lib.mkIf config.services.bind.enable {
+
+    caddy.cidrAllowlist = [ "192.168.0.0/16" ];
+
+    services.bind = {
+      cacheNetworks = [ "127.0.0.0/24" "192.168.0.0/16" ];
+      forwarders = [ "1.1.1.1" "1.0.0.1" ];
+      ipv4Only = true;
+
+      # Use rpz zone as an override
+      extraOptions = ''response-policy { zone "rpz"; };'';
+
+      zones = {
+        rpz = {
+          master = true;
+          file = pkgs.writeText "db.rpz" ''
+            $TTL 60  ; 1 minute
+            @       IN      SOA     localhost. root.localhost. (
+                                    2023071800      ; serial
+                                    1h              ; refresh
+                                    30m             ; retry
+                                    1w              ; expire
+                                    30m             ; minimum ttl
+                                    )
+                    IN      NS      localhost.
+            localhost       A       127.0.0.1
+            ${localRecords}
+          '';
+        };
+      };
+
+    };
+
+    networking.firewall.allowedTCPPorts = [ 53 ];
+    networking.firewall.allowedUDPPorts = [ 53 ];
+
+  };
+
+}

modules/nixos/services/caddy.nix

@@ -1,25 +1,40 @@
 { config, pkgs, lib, ... }: {
 
   options = {
-    caddy.tlsPolicies = lib.mkOption {
+    caddy = {
+      tlsPolicies = lib.mkOption {
         type = lib.types.listOf lib.types.attrs;
         description = "Caddy JSON TLS policies";
         default = [ ];
       };
-    caddy.routes = lib.mkOption {
+      routes = lib.mkOption {
         type = lib.types.listOf lib.types.attrs;
         description = "Caddy JSON routes for http servers";
         default = [ ];
       };
-    caddy.blocks = lib.mkOption {
+      blocks = lib.mkOption {
         type = lib.types.listOf lib.types.attrs;
         description = "Caddy JSON error blocks for http servers";
         default = [ ];
       };
+      cidrAllowlist = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        description = "CIDR blocks to allow for requests";
+        default = [ "127.0.0.1/32" ];
+      };
+    };
   };
 
-  config =
+  config = lib.mkIf config.services.caddy.enable {
-    lib.mkIf (config.services.caddy.enable && config.caddy.routes != [ ]) {
+
+    # Force Caddy to 403 if not coming from allowlisted source
+    caddy.routes = [{
+      match = [{ not = [{ remote_ip.ranges = config.caddy.cidrAllowlist; }]; }];
+      handle = [{
+        handler = "static_response";
+        status_code = "403";
+      }];
+    }];
 
     services.caddy = {
       adapter = "''"; # Required to enable JSON

modules/nixos/services/cloudflare.nix

@@ -41,13 +41,7 @@ in {
   config = lib.mkIf config.cloudflare.enable {
 
     # Forces Caddy to error if coming from a non-Cloudflare IP
-    caddy.routes = [{
+    caddy.cidrAllowlist = cloudflareIpRanges;
-      match = [{ not = [{ remote_ip.ranges = cloudflareIpRanges; }]; }];
-      handle = [{
-        handler = "static_response";
-        status_code = "403";
-      }];
-    }];
 
     # Tell Caddy to use Cloudflare DNS for ACME challenge validation
     services.caddy.package = (pkgs.callPackage ../../../overlays/caddy.nix {

modules/nixos/services/default.nix

@@ -3,6 +3,7 @@
   imports = [
     ./arr.nix
     ./backups.nix
+    ./bind.nix
     ./caddy.nix
     ./calibre.nix
     ./cloudflare-tunnel.nix