From 704f007ae588a1e0397ef3a7bf99598160304a39 Mon Sep 17 00:00:00 2001
From: Astro <astro@spaceboyz.net>
Date: Thu, 25 Mar 2021 00:46:46 +0100
Subject: [PATCH] nixos-module/network.nix: configure host IP

---
 nix/lib/config/options.nix          | 15 ++++++++
 nix/nixos-module/network.nix        | 54 +++++++++++++++++++++++------
 nix/nixos-module/server/network.nix | 10 +++++-
 3 files changed, 67 insertions(+), 12 deletions(-)

diff --git a/nix/lib/config/options.nix b/nix/lib/config/options.nix
index 7ef935e..b832f5d 100644
--- a/nix/lib/config/options.nix
+++ b/nix/lib/config/options.nix
@@ -13,6 +13,17 @@ let
         type = with types; nullOr str;
         default = null;
       };
+      subnet4Len = mkOption {
+        type = with types; nullOr types.int;
+        default =
+          let
+            inherit (config.site.net.${name}) subnet4;
+            s = lib.splitString "/" subnet4;
+          in
+            if subnet4 != null && builtins.length s == 2
+            then lib.toInt (elemAt s 1)
+            else null;
+      };
       subnets6 = mkOption {
         description = "IPv6 subnets w/o prefixlen (always 64)";
         type = with types; attrsOf str;
@@ -77,6 +88,10 @@ let
         default = {};
         type = with types; attrsOf (submodule interfaceOpts);
       };
+      isRouter = mkOption {
+        type = types.bool;
+        default = config.site.hosts.${name}.interfaces ? core;
+      };
     };
   };
 in
diff --git a/nix/nixos-module/network.nix b/nix/nixos-module/network.nix
index bf903ac..a431205 100644
--- a/nix/nixos-module/network.nix
+++ b/nix/nixos-module/network.nix
@@ -1,27 +1,59 @@
 { hostName, config, lib, pkgs, ... }:
 
+let
+  findGw6 = net: gw6:
+    let
+      inherit (config.site.net.${net}) hosts6;
+    in
+      builtins.foldl' (result: ctx:
+        let
+          h = hosts6.${ctx};
+        in
+          if result == null && h ? ${hostName} && h ? ${gw6}
+          then h.${gw6}
+          else result
+      ) null (builtins.attrNames hosts6);
+in
 {
   networking.firewall.enable = lib.mkDefault false;
 
+  networking.useDHCP = false;
+
   networking.useHostResolvConf = false;
   services.resolved.enable = false;
   environment.etc."resolv.conf".text = ''
     nameserver 172.20.73.8 9.9.9.9
   '';
-  
+
+  networking.useNetworkd = true;
   systemd.network = {
     enable = true;
 
     networks =
-      builtins.mapAttrs (ifName: { gw4, gw6, ... }: {
-        matchConfig.Name = ifName;
-        # addresses = [ {
-        #   addressConfig.Address = "127.0.0.1/8";
-        # } ];
-        # TODO: lookup hostname
-        gateway = with lib;
-          optional (gw4 != null) gw4 ++
-          optional (gw6 != null) gw6;
-      }) config.site.hosts.${hostName}.interfaces;
+      builtins.mapAttrs (ifName: { gw4, gw6, ... }:
+        let
+          netConfig = config.site.net.${ifName};
+        in {
+          matchConfig.Name = ifName;
+
+          addresses =
+            let
+              address = netConfig.hosts4.${hostName};
+              prefixLen = netConfig.subnet4Len;
+            in
+              lib.optional (netConfig.hosts4 ? ${hostName}) {
+                addressConfig.Address = "${address}/${toString prefixLen}";
+              } ++
+              builtins.concatMap (hosts6:
+                lib.optional (hosts6 ? ${hostName}) {
+                  addressConfig.Address = "${hosts6.${hostName}}/64";
+                }
+              ) (builtins.attrValues netConfig.hosts6);
+
+          gateway = with lib;
+            optional (gw4 != null) netConfig.${gw4} ++
+            optional (gw6 != null) (findGw6 ifName gw6);
+
+        }) config.site.hosts.${hostName}.interfaces;
   };
 }
diff --git a/nix/nixos-module/server/network.nix b/nix/nixos-module/server/network.nix
index f51d03e..71cdff4 100644
--- a/nix/nixos-module/server/network.nix
+++ b/nix/nixos-module/server/network.nix
@@ -65,6 +65,14 @@ in
         matchConfig.Name = "bond0";
         networkConfig.VLAN = map (net: "ext-${net}") ctNets;
       };
-    };
+    } // builtins.foldl' (result: net: result // {
+      "${net}" = {
+        matchConfig.Name = net;
+        networkConfig = {
+          IPForward = config.site.hosts.${hostName}.isRouter;
+          IPv6AcceptRA = !config.site.hosts.${hostName}.isRouter;
+        };
+      };
+    }) {} bridgeNets;
   };
 }