1 files changed, 105 insertions, 0 deletions
diff --git a/modules/wg/module.nix b/modules/wg/module.nix
new file mode 100644
index 0000000..84575c7
--- /dev/null
+++ b/modules/wg/module.nix
@@ -0,0 +1,105 @@
+{ lib
+, config
+, self
+, registry
+, ... }: {
+
+  config =
+    let
+      currenthost = config.networking.hostName;
+      wg = config.oxalab.wg;
+
+      # get all the networks we participate in
+      networks = builtins.filter (net: builtins.hasAttr "${currenthost}" net.hosts) wg;
+
+      # create wg networks
+      network-attrset = map (net: {
+        name = "30-wg-${net.networkName}";
+        value = {
+          matchConfig.Name = "wg-${net.networkName}";
+          networkConfig = {
+            Address = net.hosts.${currenthost}.address;
+            IPv6AcceptRA = false; # for now static IPv6
+          } // (if net.hosts.${currenthost}.endpoint.enable then {IPv4Forwarding=true; IPv6Forwarding=true; } else {});
+        };
+      }) networks;
+
+      systemd-networks = builtins.listToAttrs network-attrset;
+
+      # get all the networks we client in
+      net-client = builtins.filter (net: !net.hosts.${currenthost}.endpoint.enable) networks;
+      # get all the networks we are endpoint of
+      net-endpoint = builtins.filter (net: net.hosts.${currenthost}.endpoint.enable) networks;
+
+      # wg netdevs
+      # client
+      netdev-client-list = map (net: {
+        name = "30-wg-${net.networkName}";
+        value = {
+          netdevConfig = {
+            Kind = "wireguard";
+            Name = "wg-${net.networkName}";
+          };
+          wireguardConfig.PrivateKeyFile = net.hosts.${currenthost}.privateKeyFile;
+          # for client this is only endpoint for now
+          wireguardPeers =
+            let
+              endpoint = lib.attrsets.filterAttrs (_k: v: v.endpoint.enable) net.hosts;
+              wg-peers-attrs = lib.attrsets.mapAttrs (_k: v:
+              {
+                PersistentKeepalive = 29;
+                PublicKey = v.publicKey;
+                Endpoint = "${v.endpoint.endpoint}:${toString v.endpoint.port}";
+                AllowedIPs = net.CIDRs;
+              }) endpoint;
+              wg-peers = lib.attrsets.attrValues wg-peers-attrs;
+            in
+            wg-peers;
+          };
+        }) net-client;
+        netdev-client = builtins.listToAttrs netdev-client-list;
+
+        maskip = (net: hostattrs:
+        if hostattrs.endpoint.enable then hostattrs.address else map (baseaddr:
+        if lib.strings.hasInfix "." baseaddr then "${baseaddr}/32" else "${baseaddr}/128"
+        ) (map (addr: builtins.elemAt (lib.strings.splitString "/" addr) 0) hostattrs.address));
+      # endpoint
+      # TODO: this requires bit more logic for allowedIPs if we have more then
+      # 2 endpoints e.g. for routing client -> endpoint1 -> endpoint2 ->
+      # client2
+      netdev-endpoint-list =  map (net: {
+        name = "30-wg-${net.networkName}";
+        value = {
+          netdevConfig = {
+            Kind = "wireguard";
+            Name = "wg-${net.networkName}";
+          };
+          wireguardConfig.PrivateKeyFile = net.hosts.${currenthost}.privateKeyFile;
+          wireguardConfig.ListenPort = net.hosts.${currenthost}.endpoint.port;
+          wireguardPeers =
+            let
+              peers = lib.attrsets.filterAttrs (k: _v: k != currenthost) net.hosts;
+              wg-peers-attrs = lib.attrsets.mapAttrs (_k: v:
+              {
+                PersistentKeepalive = 29;
+                PublicKey = v.publicKey;
+                # only route to /32 or /128, i.e. single client
+                AllowedIPs = maskip net v;
+              } // (if !isNull v.endpoint.endpoint then { Endpoint = "${v.endpoint.endpoint}:${toString v.endpoint.port}"; } else {})) peers;
+              wg-peers = lib.attrsets.attrValues wg-peers-attrs;
+            in
+            wg-peers;
+          };
+        }) net-endpoint;
+        netdev-endpoint = builtins.listToAttrs netdev-endpoint-list;
+
+    in
+    {
+      # make sure that the networkd and wg are enabled
+      networking.wireguard.enable = true;
+      systemd.network.enable = true;
+
+      systemd.network.networks = systemd-networks;
+      systemd.network.netdevs = netdev-client // netdev-endpoint;
+    };
+  }