From 38a069e58baa899a3e911bb931d80a1acad15b66 Mon Sep 17 00:00:00 2001
From: Ember 'n0emis' Keske <git@n0emis.eu>
Date: Fri, 11 Mar 2022 22:13:37 +0100
Subject: [PATCH] configure fastd

---
 default.nix         | 33 +++++++++++++++++++++++++++++++--
 modules/default.nix | 41 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/default.nix b/default.nix
index 5394efb..4388e13 100644
--- a/default.nix
+++ b/default.nix
@@ -38,7 +38,7 @@ in
       default = {};
       type = with types; attrsOf (submodule {
         options = {
-          enable = mkEnableOption "ffnix Site";
+          enable = mkEnableOption "ffnix Domain";
           ipv4Prefix = mkOption {
             type = types.str;
           };
@@ -83,7 +83,36 @@ in
           };
           tunnels = mkOption {
             default = {};
-            type = (pkgs.formats.json {}).type;
+            type = types.submodule {
+              options = {
+                fastd = mkOption {
+                  default = {};
+                  type = types.submodule {
+                    options = {
+                      enable = mkEnableOption "Fastd Tunnel";
+                      mtu = mkOption {
+                        type = types.int;
+                        default = 1406;
+                      };
+                      port = mkOption {
+                        type = types.int;
+                        default = 10000;
+                      };
+                      interfaceMac = mkOption {
+                        type = types.str;
+                      };
+                      extraConfig = mkOption {
+                        description = ''
+                          Additional config that will me merged with the fastd-instance config
+                        '';
+                        default = {};
+                        type = (pkgs.formats.json {}).type;
+                      };
+                    };
+                  };
+                };
+              };
+            };
           };
         };
       });
diff --git a/modules/default.nix b/modules/default.nix
index 5ead52f..77ed7db 100644
--- a/modules/default.nix
+++ b/modules/default.nix
@@ -11,8 +11,10 @@ let
       mkIfName = type:
         if type == "bridge" then "br-${name}" else
         if type == "batman" then "bat-${name}" else
+        if type == "fastd" then "fd-${name}" else
         throw "unknown interface type ${type}, coud not generate name";
     in {
+      #### NULL-ROUTES ####
       networks."10-lo" = {
         routes = if !domCfg.defaultNullRoute then [] else [
           {
@@ -34,13 +36,17 @@ let
         ];
       };
 
+      #### BRIDGE ####
       netdevs."30-${mkIfName "bridge"}".netdevConfig = {
         Name = mkIfName "bridge";
         Kind = "bridge";
       };
       networks."30-${mkIfName "bridge"}" = {
         matchConfig.Name = mkIfName "bridge";
-        linkConfig.RequiredForOnline = "no";
+        linkConfig = {
+          RequiredForOnline = "no";
+          MTUBytes = "${toString domCfg.mtu}";
+        };
         address = domCfg.addresses;
         routes = map (prefix: {
           routeConfig = {
@@ -65,6 +71,7 @@ let
         }) (domCfg.ipv6Prefixes ++ [ domCfg.ipv4Prefix ]);
       };
 
+      #### BATMAN ####
       netdevs."30-${mkIfName "batman"}" = mkIf (!cfg.batmanLegacy) {
         netdevConfig = {
           Kind = "batadv";
@@ -80,6 +87,35 @@ let
         matchConfig.Name = mkIfName "batman";
         bridge = [ "${mkIfName "bridge"}" ];
       };
+
+      #### FASTD ####
+      fdInstances."${mkIfName "fastd"}" = mkIf domCfg.tunnels.fastd.enable ({
+        bind = mkDefault [ "any:${toString domCfg.tunnels.fastd.port}" ];
+        mtu = domCfg.tunnels.fastd.mtu;
+      } // domCfg.tunnels.fastd.extraConfig);
+      links."30-${mkIfName "fastd"}" = mkIf domCfg.tunnels.fastd.enable {
+        matchConfig.OriginalName = mkIfName "fastd";
+        linkConfig.MACAddress = domCfg.tunnels.fastd.interfaceMac;
+      };
+      networks."30-${mkIfName "fastd"}" = mkIf (domCfg.tunnels.fastd.enable && !cfg.batmanLegacy) {
+        matchConfig.Name = mkIfName "fastd";
+        networkConfig.BatmanAdvanced = mkIfName "batman";
+      };
+      services."${mkIfName "batman"}" = mkIf (domCfg.tunnels.fastd.enable && cfg.batmanLegacy) {
+        after = [ "fastd-${mkIfName "fastd"}.service" ];
+        requiredBy = [ "fastd-${mkIfName "fastd"}.service" ];
+
+        script = ''
+          timeout 30 ${pkgs.bash}/bin/sh -c 'while ! ${pkgs.iproute2}/bin/ip link show dev ${mkIfName "fastd"} | grep UNKNOWN ; do sleep 1; done'
+          ${pkgs.batctl-legacy}/bin/batctl -m ${mkIfName "batman"} interface add ${mkIfName "fastd"} || true
+          ${pkgs.batctl-legacy}/bin/batctl -m ${mkIfName "batman"} gw_mode server || true
+        '';
+
+        serviceConfig =  {
+          Type = "oneshot";
+          RemainAfterExit = true;
+        };
+      };
     };
 
     domConfigs = map (key: getAttr key (mapAttrs mkDomain activeDomains)) (attrNames activeDomains);
@@ -91,5 +127,8 @@ in
     environment.etc."ffnix.json".source = pkgs.writeText "ffnix.json" (generators.toJSON {} activeDomains);
     systemd.network.netdevs = mergedConfigs.netdevs;
     systemd.network.networks = mergedConfigs.networks;
+    systemd.network.links = mergedConfigs.links;
+    systemd.services = mergedConfigs.services;
+    ffnix.fastd.instances = mergedConfigs.fdInstances;
   };
 }