From b55cc2deaf2923fac26871d522b7a1bc04db5a03 Mon Sep 17 00:00:00 2001
From: Simon Bruder <simon@sbruder.de>
Date: Sun, 22 Sep 2024 11:26:36 +0200
Subject: [PATCH] shinobu/router: Allow adding static hosts

This is required to have them available in nftables rules without too
much headache.
---
 machines/shinobu/services/router/common.nix  | 36 +++++++++++++++++++-
 machines/shinobu/services/router/dnsmasq.nix |  4 +++
 machines/shinobu/services/router/nft.nix     |  9 +++--
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/machines/shinobu/services/router/common.nix b/machines/shinobu/services/router/common.nix
index f2a214d..9b6570e 100644
--- a/machines/shinobu/services/router/common.nix
+++ b/machines/shinobu/services/router/common.nix
@@ -26,12 +26,35 @@ let
         cidr = v6;
         net = fst v6Split;
         suffix = snd v6Split;
+        withoutLocalComponent = lib.substring 0 ((lib.stringLength net) - 1) net;
         gateway = "${net}1";
         gatewayCidr = "${gateway}/${suffix}";
       };
     };
+
+  macToIpv6InterfaceIdentifier = mac:
+    let
+      macList = lib.splitString ":" mac;
+      macListIpv6 = lib.flatten [
+        (lib.toHexString (lib.bitXor (builtins.fromTOML "x = 0x${lib.elemAt macList 0}").x 2))
+        (lib.sublist 1 2 macList)
+        [ "ff" "fe" ]
+        (lib.sublist 3 3 macList)
+      ];
+      interfaceIdentifierNoColons = lib.strings.toLower (lib.concatStrings macListIpv6);
+      interfaceIdentifier = lib.concatStrings [
+        (lib.substring 0 4 interfaceIdentifierNoColons)
+        ":"
+        (lib.substring 4 4 interfaceIdentifierNoColons)
+        ":"
+        (lib.substring 8 4 interfaceIdentifierNoColons)
+        ":"
+        (lib.substring 12 4 interfaceIdentifierNoColons)
+      ];
+    in
+    interfaceIdentifier;
 in
-{
+rec {
   vlan = {
     lan = {
       id = 10;
@@ -123,4 +146,15 @@ in
       }
     ];
   };
+  staticHosts = lib.mapAttrs
+    (_: options: options // {
+      address6 = "${vlan.${options.vlan}.subnet.v6.withoutLocalComponent}${macToIpv6InterfaceIdentifier options.hwaddr}";
+    })
+    {
+      fuuko = {
+        hwaddr = "18:c0:4d:d2:93:f0";
+        address4 = "10.80.1.98";
+        vlan = "lan";
+      };
+    };
 }
diff --git a/machines/shinobu/services/router/dnsmasq.nix b/machines/shinobu/services/router/dnsmasq.nix
index a447154..abe66b6 100644
--- a/machines/shinobu/services/router/dnsmasq.nix
+++ b/machines/shinobu/services/router/dnsmasq.nix
@@ -56,6 +56,10 @@ in
         ])
         cfg.vlan);
 
+      dhcp-host = lib.mapAttrsToList
+        (name: { hwaddr, address4, vlan, ... }: "${hwaddr},tag:br-${vlan},${address4},${name}")
+        cfg.staticHosts;
+
       nftset = [
         "/${lib.concatStringsSep "/" bypassHe}/6#ip6#he-bypass#addresses"
       ];
diff --git a/machines/shinobu/services/router/nft.nix b/machines/shinobu/services/router/nft.nix
index e82c48b..dfc13ac 100644
--- a/machines/shinobu/services/router/nft.nix
+++ b/machines/shinobu/services/router/nft.nix
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2023 Simon Bruder <simon@sbruder.de>
+# SPDX-FileCopyrightText: 2023-2024 Simon Bruder <simon@sbruder.de>
 #
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
@@ -17,7 +17,12 @@ let
   passthru = {
     VLANS = lib.attrNames cfg.vlan;
     VLAN_BRIDGES = map (name: "br-${name}") (lib.attrNames cfg.vlan);
-  };
+  } // (lib.listToAttrs (lib.flatten (lib.mapAttrsToList
+    (name: staticHostConfig:
+      (map
+        (option: option // { name = "STATIC_HOST_${name}_${option.name}"; })
+        (lib.attrsToList staticHostConfig)))
+    cfg.staticHosts)));
 
   defines = lib.concatStringsSep
     "\n"