1 files changed, 171 insertions, 0 deletions
diff --git a/nixos/modules/router.nix b/nixos/modules/router.nix
new file mode 100644
index 0000000..ed634b1
--- /dev/null
+++ b/nixos/modules/router.nix
@@ -0,0 +1,171 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkOption types mkIf mapAttrsToList;
+  cnf = config.cynerd.router;
+in {
+  options = {
+    cynerd.router = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Enable router support";
+      };
+      wan = mkOption {
+        type = types.str;
+        description = "Interface for the router's WAN";
+      };
+      lanIP = mkOption {
+        type = types.str;
+        description = "LAN IP address";
+      };
+      dynIPStart = mkOption {
+        type = types.ints.between 0 256;
+        default = 100;
+        description = "Offset for the dynamic IPv4 addresses";
+      };
+      dynIPCount = mkOption {
+        type = types.ints.between 0 256;
+        default = 100;
+        description = "Number of dynamically assigned IPv4 addresses";
+      };
+      lanPrefix = mkOption {
+        type = types.ints.between 0 32;
+        default = 24;
+        description = "LAN IP network prefix length";
+      };
+      staticLeases = mkOption {
+        type = with types; attrsOf str;
+        default = {};
+        example = ''
+          {"xx:xx:xx:xx:xx:xx" = "10.8.1.30";}
+        '';
+        description = "Mapping of MAC address to IP address";
+      };
+    };
+  };
+
+  config = mkIf cnf.enable {
+    networking = {
+      useNetworkd = true;
+      nftables.enable = true;
+      firewall = {
+        logRefusedConnections = false;
+        interfaces = {
+          "home" = {allowedUDPPorts = [67 68];};
+          "guest" = {allowedUDPPorts = [67 68];};
+        };
+        rejectPackets = true;
+        filterForward = true;
+      };
+      nat = {
+        enable = true;
+        externalInterface = cnf.wan;
+        internalInterfaces = ["home" "guest"];
+      };
+    };
+
+    systemd.network = {
+      netdevs = {
+        "brlan" = {
+          netdevConfig = {
+            Kind = "bridge";
+            Name = "brlan";
+          };
+          extraConfig = ''
+            [Bridge]
+            DefaultPVID=none
+            VLANFiltering=yes
+          '';
+        };
+        "home" = {
+          netdevConfig = {
+            Kind = "vlan";
+            Name = "home";
+          };
+          vlanConfig.Id = 1;
+        };
+        "guest" = {
+          netdevConfig = {
+            Kind = "vlan";
+            Name = "guest";
+          };
+          vlanConfig.Id = 2;
+        };
+      };
+      networks = {
+        "brlan" = {
+          matchConfig.Name = "brlan";
+          networkConfig.VLAN = ["home" "guest"];
+          bridgeVLANs = [
+            {bridgeVLANConfig.VLAN = 1;}
+            {bridgeVLANConfig.VLAN = 2;}
+          ];
+        };
+        "home" = {
+          matchConfig.Name = "home";
+          networkConfig = {
+            Address = "${cnf.lanIP}/${toString cnf.lanPrefix}";
+            IPForward = "yes";
+            DHCPServer = "yes";
+            DHCPPrefixDelegation = "yes";
+            IPv6SendRA = "yes";
+            IPv6AcceptRA = "no";
+          };
+          dhcpServerConfig = {
+            UplinkInterface = cnf.wan;
+            PoolOffset = cnf.dynIPStart;
+            PoolSize = cnf.dynIPCount;
+            EmitDNS = "yes";
+            DNS = "1.1.1.1";
+          };
+          dhcpServerStaticLeases =
+            mapAttrsToList (n: v: {
+              dhcpServerStaticLeaseConfig = {
+                MACAddress = n;
+                Address = v;
+              };
+            })
+            cnf.staticLeases;
+          dhcpPrefixDelegationConfig = {
+            UplinkInterface = cnf.wan;
+            SubnetId = 1;
+            Announce = "yes";
+          };
+        };
+        "guest" = {
+          matchConfig.Name = "guest";
+          networkConfig = {
+            Address = "192.168.1.1/24";
+            IPForward = "yes";
+            DHCPServer = "yes";
+            DHCPPrefixDelegation = "yes";
+            IPv6SendRA = "yes";
+            IPv6AcceptRA = "no";
+          };
+          dhcpServerConfig = {
+            UplinkInterface = cnf.wan;
+            PoolOffset = cnf.dynIPStart;
+            PoolSize = cnf.dynIPCount;
+            EmitDNS = "yes";
+            DNS = "1.1.1.1";
+          };
+          dhcpPrefixDelegationConfig = {
+            UplinkInterface = cnf.wan;
+            SubnetId = 2;
+            Announce = "yes";
+          };
+        };
+      };
+      wait-online.anyInterface = true;
+    };
+
+    services.resolved = {
+      enable = true;
+      dnssec = "true";
+      fallbackDns = ["1.1.1.1" "8.8.8.8"];
+    };
+  };
+}