1 files changed, 42 insertions, 0 deletions
diff --git a/hosts/kay/modules/router.nix b/hosts/kay/modules/router.nix
new file mode 100644
index 0000000..c33fff2
--- /dev/null
+++ b/hosts/kay/modules/router.nix
@@ -0,0 +1,42 @@
+{ ... }:
+
+let
+  lanInterface = "enp4s0";
+  wanInterface = "ppp0";
+  subnet = "10.0.0.0";
+  prefix = 24;
+  host = "10.0.0.1";
+  leaseRangeStart = "10.0.0.100";
+  leaseRangeEnd = "10.0.0.240";
+in
+{
+  networking = {
+    nat.enable = true;
+    useDHCP = false;
+    interfaces."${lanInterface}" = {
+      ipv4.addresses = [{ 
+        address = host;
+        prefixLength  = prefix;
+      }];
+    };
+    firewall = {
+      extraCommands = ''
+        # nat datagrams comming through lanInterface to wanInterface
+        iptables -t nat -I POSTROUTING 1 -s ${subnet}/${toString prefix} -o ${wanInterface} -j MASQUERADE
+
+        # allow all traffic on lanInterface interface
+        iptables -I INPUT 1 -i ${lanInterface} -j ACCEPT
+
+        # forward rules
+        iptables -I FORWARD 1 -i ${lanInterface} -o ${lanInterface} -j ACCEPT
+        iptables -I FORWARD 1 -i ${wanInterface} -o ${lanInterface} -j ACCEPT
+        iptables -I FORWARD 1 -i ${lanInterface} -o ${wanInterface} -j ACCEPT
+      '';
+    };
+  };
+
+  services.dnsmasq.settings = {
+    dhcp-range = [ "${leaseRangeStart},${leaseRangeEnd}" ];
+    interface = lanInterface;
+  };
+}