From 3609d8d5ee5c90a11c0bdb0a3819765681e8a59f Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Thu, 31 Aug 2023 23:24:23 +0100
Subject: [PATCH] implement route as module-based-service

---
 examples/rotuer.nix         | 13 +++----------
 modules/network/default.nix | 25 +++++++++++++++++++++++++
 modules/network/route.nix   | 20 ++++++++++++++++++++
 3 files changed, 48 insertions(+), 10 deletions(-)
 create mode 100644 modules/network/route.nix

diff --git a/examples/rotuer.nix b/examples/rotuer.nix
index bfe1c41..eef0748 100644
--- a/examples/rotuer.nix
+++ b/examples/rotuer.nix
@@ -9,10 +9,6 @@
 { config, pkgs, lib, ... } :
 let
   secrets = import ./rotuer-secrets.nix;
-  inherit (pkgs.liminix.networking)
-    address
-    interface
-    route;
   inherit (pkgs.liminix.services) oneshot longrun bundle target;
   inherit (pkgs)
     dropbear
@@ -144,19 +140,16 @@ in rec {
     };
 
 
-  services.defaultroute4 = route {
-    name = "defaultroute4";
+  services.defaultroute4 = svc.network.route.build {
     via = "$(output ${services.wan} address)";
     target = "default";
     dependencies = [ services.wan ];
   };
 
-  services.defaultroute6 = route {
-    name = "defaultroute6";
+  services.defaultroute6 = svc.network.route.build {
     via = "$(output ${services.wan} ipv6-peer-address)";
     target = "default";
-    dev = "$(output ${services.wan} ifname)";
-    dependencies = [ services.wan ];
+    interface = services.wan;
   };
 
   services.firewall = svc.firewall.build {
diff --git a/modules/network/default.nix b/modules/network/default.nix
index 8bdcee2..7e82145 100644
--- a/modules/network/default.nix
+++ b/modules/network/default.nix
@@ -21,6 +21,9 @@ in {
         description = "network interface address";
         type = liminix.lib.types.serviceDefn;
       };
+      route = mkOption {
+        type = liminix.lib.types.serviceDefn;
+      };
       dhcp = {
         client = mkOption {
           # this needs to move to its own service as it has
@@ -82,6 +85,28 @@ in {
           type = types.ints.between 0 128;
         };
       };
+
+      route = liminix.callService ./route.nix {
+        interface = mkOption {
+          type = types.nullOr liminix.lib.types.interface;
+          default = null;
+          description = "Interface to route through. May be omitted if it can be inferred from \"via\"";
+        };
+        target = mkOption {
+          type = types.str;
+          description = "host or network to add route to";
+        };
+        via = mkOption {
+          type = types.str;
+          description = "address of next hop";
+        };
+        metric = mkOption {
+          type = types.int;
+          description = "route metric";
+          default = 100;
+        };
+      };
+
       dhcp.client = liminix.callService ./dhcpc.nix {
         interface = mkOption {
           type = liminix.lib.types.service;
diff --git a/modules/network/route.nix b/modules/network/route.nix
new file mode 100644
index 0000000..25c817a
--- /dev/null
+++ b/modules/network/route.nix
@@ -0,0 +1,20 @@
+{
+  liminix
+, ifwait
+, serviceFns
+, lib
+}:
+{ target, via, interface ? null, metric }:
+let
+  inherit (liminix.services) oneshot;
+  with_dev = if interface != null then "dev $(input ${interface} ifname)" else "";
+in oneshot {
+  name = "route-${target}-${builtins.substring 0 12 (builtins.hashString "sha256" "${via}-${if interface!=null then interface.name else ""}")}";
+  up = ''
+    ip route add ${target} via ${via} metric ${toString metric} ${with_dev}
+  '';
+  down = ''
+    ip route del ${target} via ${via} ${with_dev}
+  '';
+  dependencies = [] ++ lib.optional (interface != null) interface;
+}