services/enthalpy: complete migration to networking.netns

nixos/hosts/marisa-7d76/networking.nix

@@ -1,12 +1,15 @@
-{ profiles, lib, ... }:
+{
+  config,
+  profiles,
+  lib,
+  ...
+}:
 {
   imports = with profiles; [
     services.enthalpy
   ];
 
   services.enthalpy = {
-    users.rebmit = { };
-    services.nix-daemon = { };
     ipsec.interfaces = [ "enp14s0" ];
     clat = {
       enable = true;
@@ -15,6 +18,19 @@
     gost.enable = true;
   };
 
+  systemd.services.nix-daemon = {
+    serviceConfig = config.networking.netns.enthalpy.serviceConfig;
+    after = [ "netns-enthalpy.service" ];
+    requires = [ "netns-enthalpy.service" ];
+  };
+
+  systemd.services."user@${toString config.users.users.rebmit.uid}" = {
+    overrideStrategy = "asDropin";
+    serviceConfig = config.networking.netns.enthalpy.serviceConfig;
+    after = [ "netns-enthalpy.service" ];
+    requires = [ "netns-enthalpy.service" ];
+  };
+
   systemd.network = {
     enable = true;
     wait-online.anyInterface = true;

nixos/hosts/marisa-a7s/networking.nix

@@ -1,12 +1,15 @@
-{ profiles, lib, ... }:
+{
+  config,
+  profiles,
+  lib,
+  ...
+}:
 {
   imports = with profiles; [
     services.enthalpy
   ];
 
   services.enthalpy = {
-    users.rebmit = { };
-    services.nix-daemon = { };
     ipsec = {
       interfaces = [ "wlan0" ];
       whitelist = [ "rebmit's edge network" ];
@@ -18,6 +21,19 @@
     gost.enable = true;
   };
 
+  systemd.services.nix-daemon = {
+    serviceConfig = config.networking.netns.enthalpy.serviceConfig;
+    after = [ "netns-enthalpy.service" ];
+    requires = [ "netns-enthalpy.service" ];
+  };
+
+  systemd.services."user@${toString config.users.users.rebmit.uid}" = {
+    overrideStrategy = "asDropin";
+    serviceConfig = config.networking.netns.enthalpy.serviceConfig;
+    after = [ "netns-enthalpy.service" ];
+    requires = [ "netns-enthalpy.service" ];
+  };
+
   systemd.network = {
     enable = true;
     wait-online.anyInterface = true;

nixos/hosts/reisen-sin0/networking.nix

@@ -1,7 +1,6 @@
 {
   profiles,
   data,
-  lib,
   ...
 }:
 {
@@ -57,12 +56,6 @@
         dhcpV6Config.RouteMetric = 1024;
         ipv6AcceptRAConfig.RouteMetric = 1024;
       };
-      "50-enthalpy" = {
-        routes = lib.singleton {
-          Destination = data.enthalpy_network_prefix;
-          Gateway = "fe80::ff:fe00:0";
-        };
-      };
     };
   };
 }

nixos/modules/networking/netns/common.nix

@@ -26,7 +26,7 @@ in
             };
             mntnsPath = mkOption {
               type = types.str;
-              default = if name == "default" then "/proc/1/ns/mnt" else "/run/netns-${name}/mntns/${name}";
+              default = if name == "default" then "/proc/1/ns/mnt" else "/run/${name}/mntns/${name}";
               readOnly = true;
               description = ''
                 Path to the auxiliary mount namespace.
@@ -71,7 +71,7 @@ in
                     BindReadOnlyPaths = optionals config.enableDNSIsolation [
                       "/etc/netns/${name}/resolv.conf:/etc/resolv.conf:norbind"
                       "/etc/netns/${name}/nsswitch.conf:/etc/nsswitch.conf:norbind"
-                      "/run/netns-${name}/nscd:/run/nscd:norbind"
+                      "/run/${name}/nscd:/run/nscd:norbind"
                     ];
                   };
               readOnly = true;
@@ -143,13 +143,13 @@ in
             ${optionalString enableDNSIsolation ''
               nsenter --mount=${mntnsPath} mount --bind --read-only /etc/netns/${name}/resolv.conf /etc/resolv.conf
               nsenter --mount=${mntnsPath} mount --bind --read-only /etc/netns/${name}/nsswitch.conf /etc/nsswitch.conf
-              nsenter --mount=${mntnsPath} mount --bind --read-only /run/netns-${name}/nscd /run/nscd
+              nsenter --mount=${mntnsPath} mount --bind --read-only /run/${name}/nscd /run/nscd
             ''}
           '';
           serviceConfig = {
             Type = "oneshot";
             RemainAfterExit = true;
-            RuntimeDirectory = "netns-${name}/mntns";
+            RuntimeDirectory = "${name}/mntns";
           };
           after =
             [

nixos/modules/networking/netns/extra-veth.nix

@@ -1,127 +0,0 @@
-{
-  config,
-  lib,
-  pkgs,
-  ...
-}:
-with lib;
-let
-  allNetns = config.networking.netns;
-  allExtraVeths = flatten (mapAttrsToList (_name: cfg: cfg.extraVeths) allNetns);
-in
-{
-  options.networking.netns = mkOption {
-    type = types.attrsOf (
-      types.submodule (
-        { name, ... }:
-        {
-          options.extraVeths = mkOption {
-            type = types.listOf (
-              types.submodule (
-                { config, ... }:
-                {
-                  options = {
-                    sourceNetns = mkOption {
-                      type = types.str;
-                      default = name;
-                      readOnly = true;
-                      description = ''
-                        The current network namespace.
-                      '';
-                    };
-                    targetNetns = mkOption {
-                      type = types.str;
-                      description = ''
-                        The network namespace to connect to.
-                      '';
-                    };
-                    sourceInterface = mkOption {
-                      type = types.str;
-                      default = if config.targetNetns == "default" then "host" else config.targetNetns;
-                      description = ''
-                        The interface name in the current network namespace;
-                      '';
-                    };
-                    targetInterface = mkOption {
-                      type = types.str;
-                      default = if config.sourceNetns == "default" then "host" else config.sourceNetns;
-                      description = ''
-                        The interface name in the other network namespace;
-                      '';
-                    };
-                  };
-                }
-              )
-            );
-            default = [ ];
-            description = ''
-              Extra veth-pairs to be created for enabling link-scope connectivity
-              between inter-network namespaces.
-              Note that a veth-pair only needs to be defined on one end.
-            '';
-          };
-        }
-      )
-    );
-  };
-
-  config = {
-    systemd.services = listToAttrs (
-      map (
-        ev:
-        let
-          inherit (ev)
-            sourceNetns
-            targetNetns
-            sourceInterface
-            targetInterface
-            ;
-          sourceNetnsPath = config.networking.netns.${sourceNetns}.netnsPath;
-          targetNetnsPath = config.networking.netns.${targetNetns}.netnsPath;
-          serviceDeps = map (ns: "netns-${ns}.service") (
-            filter (ns: ns != "default") [
-              sourceNetns
-              targetNetns
-            ]
-          );
-          mkSetup =
-            netns: _netnsPath: interface:
-            if netns == "default" then
-              "ip link set ${interface} up"
-            else
-              "ip -n ${netns} link set ${interface} up";
-          mkDrop =
-            netns: _netnsPath: interface:
-            if netns == "default" then "ip link del ${interface}" else "ip -n ${netns} link del ${interface}";
-        in
-        nameValuePair "netns-extra-veth-1-${sourceNetns}-${targetNetns}" {
-          path = with pkgs; [
-            coreutils
-            iproute2
-            procps
-          ];
-          script = ''
-            ip link add ${sourceInterface} mtu 1400 address 02:00:00:00:00:01 netns ${sourceNetnsPath} type veth \
-              peer ${targetInterface} mtu 1400 address 02:00:00:00:00:00 netns ${targetNetnsPath}
-            ${mkSetup sourceNetns sourceNetnsPath sourceInterface}
-            ${mkSetup targetNetns targetNetnsPath targetInterface}
-          '';
-          preStop = ''
-            ${mkDrop sourceNetns sourceNetnsPath sourceInterface}
-          '';
-          serviceConfig = {
-            Type = "oneshot";
-            RemainAfterExit = true;
-          };
-          after = [
-            "network.target"
-          ] ++ serviceDeps;
-          partOf = serviceDeps;
-          wantedBy = [
-            "multi-user.target"
-          ] ++ serviceDeps;
-        }
-      ) allExtraVeths
-    );
-  };
-}

nixos/modules/networking/netns/nscd.nix

@@ -43,12 +43,12 @@ in
             "/etc/netns/${name}/resolv.conf:/etc/resolv.conf:norbind"
             "/etc/netns/${name}/nsswitch.conf:/etc/nsswitch.conf:norbind"
           ];
-          BindPaths = [ "/run/netns-${name}/nscd:/run/nscd:norbind" ];
+          BindPaths = [ "/run/${name}/nscd:/run/nscd:norbind" ];
           Type = "notify";
           Restart = "on-failure";
           RestartSec = 5;
           User = "${name}-nscd";
-          RuntimeDirectory = "netns-${name}/nscd";
+          RuntimeDirectory = "${name}/nscd";
           RuntimeDirectoryPreserve = true;
           ExecStart = "${pkgs.nsncd}/bin/nsncd";
         };

nixos/modules/networking/netns/port-forward.nix

@@ -84,7 +84,7 @@ in
                 ]
               );
             in
-            nameValuePair "netns-${name}-port-forward-${toString index}" {
+            nameValuePair "netns-${name}-port-forward-${toString index}-${netns}-${protocol}" {
               serviceConfig =
                 mylib.misc.serviceHardened
                 // cfg.serviceConfig

nixos/modules/services/enthalpy/bird.nix

@@ -16,7 +16,7 @@ in
     enable = mkEnableOption "bird for site-scope connectivity";
     socket = mkOption {
       type = types.str;
-      default = "/run/netns-${cfg.netns}/bird/bird.ctl";
+      default = "/run/enthalpy/bird/bird.ctl";
       description = ''
         Path to the bird control socket.
       '';
@@ -43,7 +43,7 @@ in
   };
 
   config = mkIf (cfg.enable && cfg.bird.enable) {
-    environment.etc."netns/${cfg.netns}/bird.conf".source = pkgs.writeTextFile {
+    environment.etc."enthalpy/bird/bird.conf".source = pkgs.writeTextFile {
       name = "bird";
       text = cfg.bird.config;
       checkPhase = optionalString cfg.bird.checkConfig ''
@@ -55,14 +55,14 @@ in
     systemd.services.enthalpy-bird = {
       serviceConfig =
         mylib.misc.serviceHardened
-        // config.networking.netns.${cfg.netns}.serviceConfig
+        // config.networking.netns.enthalpy.serviceConfig
         // {
           Type = "forking";
           Restart = "on-failure";
           RestartSec = 5;
           DynamicUser = true;
-          RuntimeDirectory = "netns-${cfg.netns}/bird";
+          RuntimeDirectory = "enthalpy/bird";
-          ExecStart = "${pkgs.bird}/bin/bird -s ${cfg.bird.socket} -c /etc/netns/${cfg.netns}/bird.conf";
+          ExecStart = "${pkgs.bird}/bin/bird -s ${cfg.bird.socket} -c /etc/enthalpy/bird/bird.conf";
           ExecReload = "${pkgs.bird}/bin/birdc -s ${cfg.bird.socket} configure";
           ExecStop = "${pkgs.bird}/bin/birdc -s ${cfg.bird.socket} down";
           CapabilityBoundingSet = [
@@ -82,13 +82,13 @@ in
             "AF_NETLINK"
           ];
         };
-      after = [ "netns-${cfg.netns}.service" ];
+      after = [ "netns-enthalpy.service" ];
-      partOf = [ "netns-${cfg.netns}.service" ];
+      partOf = [ "netns-enthalpy.service" ];
       wantedBy = [
         "multi-user.target"
-        "netns-${cfg.netns}.service"
+        "netns-enthalpy.service"
       ];
-      reloadTriggers = [ config.environment.etc."netns/${cfg.netns}/bird.conf".source ];
+      reloadTriggers = [ config.environment.etc."enthalpy/bird/bird.conf".source ];
     };
 
     services.enthalpy.bird.config = mkBefore ''

nixos/modules/services/enthalpy/clat.nix

@@ -11,7 +11,7 @@ with lib;
 let
   inherit (mylib.network) cidr;
   cfg = config.services.enthalpy;
-  interface = config.networking.netns.${cfg.netns}.interface;
+  interface = config.networking.netns.enthalpy.interface;
 in
 {
   options.services.enthalpy.clat = {
@@ -61,7 +61,7 @@ in
       '';
       serviceConfig =
         mylib.misc.serviceHardened
-        // config.networking.netns.${cfg.netns}.serviceConfig
+        // config.networking.netns.enthalpy.serviceConfig
         // {
           Type = "forking";
           Restart = "on-failure";
@@ -77,11 +77,11 @@ in
           ];
           PrivateDevices = false;
         };
-      after = [ "netns-${cfg.netns}.service" ];
+      after = [ "netns-enthalpy.service" ];
-      partOf = [ "netns-${cfg.netns}.service" ];
+      partOf = [ "netns-enthalpy.service" ];
       wantedBy = [
         "multi-user.target"
-        "netns-${cfg.netns}.service"
+        "netns-enthalpy.service"
       ];
     };
   };

nixos/modules/services/enthalpy/common.nix

@@ -27,13 +27,6 @@ in
         Address to be added into the enthalpy network as source address.
       '';
     };
-    netns = mkOption {
-      type = types.str;
-      default = "enthalpy";
-      description = ''
-        Name of the network namespace for enthalpy interfaces.
-      '';
-    };
     network = mkOption {
       type = types.str;
       description = ''
@@ -43,8 +36,8 @@ in
   };
 
   config = mkIf cfg.enable {
-    networking.netns."${cfg.netns}" = {
+    networking.netns.enthalpy = {
-      interface = cfg.netns;
+      interface = "enthalpy";
       address = singleton "${cfg.address}/128";
       enableIPv4Forwarding = false;
       enableIPv6Forwarding = true;

nixos/modules/services/enthalpy/exit.nix

@@ -10,10 +10,7 @@ with lib;
 let
   cfg = config.services.enthalpy;
   birdPrefix = filter (p: p.type == "bird") cfg.exit.prefix;
-  staticPrefix = subtractLists birdPrefix cfg.exit.prefix;
+  staticPrefix = filter (p: p.type == "static") cfg.exit.prefix;
-  staticRoutes = map (
-    p: "${p.destination} from ${p.source} via fe80::ff:fe00:1 dev enthalpy"
-  ) staticPrefix;
 in
 {
   options.services.enthalpy.exit = {
@@ -45,29 +42,53 @@ in
   };
 
   config = mkIf (cfg.enable && cfg.exit.enable) {
+    systemd.network.networks."50-enthalpy" = {
+      matchConfig.Name = "enthalpy";
+      routes = singleton {
+        Destination = cfg.network;
+        Gateway = "fe80::ff:fe00:2";
+      };
+      linkConfig.RequiredForOnline = false;
+    };
+
     services.enthalpy.bird.config = ''
       protocol static {
         ipv6 sadr;
         ${
           concatMapStringsSep "\n" (p: ''
-            route ${p.destination} from ${p.source} via fe80::ff:fe00:1 dev "enthalpy";
+            route ${p.destination} from ${p.source} via fe80::ff:fe00:1 dev "host";
           '') birdPrefix
         }
       }
     '';
 
-    systemd.services.enthalpy-exit = mkIf (staticRoutes != [ ]) {
+    systemd.services.enthalpy-exit = {
+      path = with pkgs; [
+        coreutils
+        iproute2
+      ];
+      script = ''
+        ip link add enthalpy mtu 1400 address 02:00:00:00:00:01 type veth \
+          peer host mtu 1400 address 02:00:00:00:00:02 netns enthalpy
+        ip link set enthalpy up
+        ip -n enthalpy link set host up
+        ${concatMapStringsSep "\n" (
+          p: "ip -n enthalpy -6 route add ${p.destination} from ${p.source} via fe80::ff:fe00:1 dev host"
+        ) staticPrefix}
+      '';
+      preStop = ''
+        ip link del enthalpy
+      '';
       serviceConfig = {
         Type = "oneshot";
         RemainAfterExit = true;
-        ExecStart = builtins.map (route: "${pkgs.iproute2}/bin/ip -6 route add ${route}") staticRoutes;
-        ExecStop = builtins.map (route: "${pkgs.iproute2}/bin/ip -6 route del ${route}") staticRoutes;
       };
-      after = [ "network.target" ];
+      after = [ "netns-enthalpy.service" ];
-      wants = [ "network.target" ];
+      partOf = [ "netns-enthalpy.service" ];
-      wantedBy = [ "multi-user.target" ];
+      wantedBy = [
+        "multi-user.target"
+        "netns-enthalpy.service"
+      ];
     };
-
-    services.enthalpy.services.enthalpy-exit = mkIf (staticRoutes != [ ]) { };
   };
 }

nixos/modules/services/enthalpy/gost.nix

@@ -25,15 +25,15 @@ in
         DynamicUser = true;
         ExecStart = "${pkgs.gost}/bin/gost -L=socks5://[::1]:${toString config.networking.ports.enthalpy-gost}";
       };
-      after = [ "netns-${cfg.netns}.service" ];
+      after = [ "netns-enthalpy.service" ];
-      partOf = [ "netns-${cfg.netns}.service" ];
+      partOf = [ "netns-enthalpy.service" ];
       wantedBy = [
         "multi-user.target"
-        "netns-${cfg.netns}.service"
+        "netns-enthalpy.service"
       ];
     };
 
-    networking.netns."${cfg.netns}".forwardPorts = singleton {
+    networking.netns.enthalpy.forwardPorts = singleton {
       protocol = "tcp";
       netns = "default";
       source = "[::1]:${toString config.networking.ports.enthalpy-gost}";

nixos/modules/services/enthalpy/ipsec.nix

@@ -4,6 +4,7 @@
   config,
   lib,
   pkgs,
+  mylib,
   ...
 }:
 with lib;
@@ -42,14 +43,6 @@ in
         List of endpoints available on this node.
       '';
     };
-    port = mkOption {
-      type = types.port;
-      default = config.networking.ports.enthalpy-ipsec;
-      readOnly = true;
-      description = ''
-        UDP port used by IKEv2. NAT-T is enabled by default.
-      '';
-    };
     interfaces = mkOption {
       type = types.listOf types.str;
       default = [ ];
@@ -99,25 +92,25 @@ in
       }
     ];
 
-    environment.systemPackages = with pkgs; [ strongswan ];
+    environment.etc."enthalpy/ranet/config.json".source =
-
+      (pkgs.formats.json { }).generate "enthalpy-ranet-config-json"
-    environment.etc."ranet/config.json".source = (pkgs.formats.json { }).generate "config.json" {
+        {
           organization = cfg.ipsec.organization;
           common_name = cfg.ipsec.commonName;
           endpoints = builtins.map (ep: {
             serial_number = ep.serialNumber;
             address_family = ep.addressFamily;
             address = ep.address;
-        port = cfg.ipsec.port;
+            port = config.networking.ports.enthalpy-ipsec;
             updown = pkgs.writeShellScript "updown" ''
               LINK=enta$(printf '%08x\n' "$PLUTO_IF_ID_OUT")
               case "$PLUTO_VERB" in
                 up-client)
                   ip link add "$LINK" type xfrm if_id "$PLUTO_IF_ID_OUT"
-              ip link set "$LINK" netns ${cfg.netns} multicast on mtu 1400 up
+                  ip link set "$LINK" netns enthalpy multicast on mtu 1400 up
                   ;;
                 down-client)
-              ip -n ${cfg.netns} link del "$LINK"
+                  ip -n enthalpy link del "$LINK"
                   ;;
               esac
             '';
@@ -130,7 +123,7 @@ in
         charon {
           interfaces_use = ${strings.concatStringsSep "," cfg.ipsec.interfaces}
           port = 0
-          port_nat_t = ${toString cfg.ipsec.port}
+          port_nat_t = ${toString config.networking.ports.enthalpy-ipsec}
           retransmit_base = 1
           plugins {
             socket-default {
@@ -168,7 +161,7 @@ in
             ''
           else
             cfg.ipsec.registry;
-        command = "ranet -c /etc/ranet/config.json -r ${registry} -k ${cfg.ipsec.privateKeyPath}";
+        command = "ranet -c /etc/enthalpy/ranet/config.json -r ${registry} -k ${cfg.ipsec.privateKeyPath}";
       in
       {
         path = with pkgs; [
@@ -178,7 +171,7 @@ in
         script = "${command} up";
         reload = "${command} up";
         preStop = "${command} down";
-        serviceConfig = {
+        serviceConfig = mylib.misc.serviceHardened // {
           Type = "oneshot";
           RemainAfterExit = true;
         };
@@ -189,16 +182,17 @@ in
           "network-online.target"
           "strongswan-swanctl.service"
         ];
-        requires = [
-          "netns-enthalpy.service"
-        ];
         after = [
           "network-online.target"
+          "netns-enthalpy.service"
           "strongswan-swanctl.service"
+        ];
+        partOf = [ "netns-enthalpy.service" ];
+        wantedBy = [
+          "multi-user.target"
           "netns-enthalpy.service"
         ];
-        wantedBy = [ "multi-user.target" ];
+        reloadTriggers = [ config.environment.etc."enthalpy/ranet/config.json".source ];
-        reloadTriggers = [ config.environment.etc."ranet/config.json".source ];
       };
   };
 }

nixos/modules/services/enthalpy/nat64.nix

@@ -4,6 +4,7 @@
   config,
   lib,
   pkgs,
+  mylib,
   ...
 }:
 with lib;
@@ -13,14 +14,6 @@ in
 {
   options.services.enthalpy.nat64 = {
     enable = mkEnableOption "NAT64";
-    table = mkOption {
-      type = types.int;
-      default = config.networking.routingTables.nat64;
-      readOnly = true;
-      description = ''
-        Routing table used for NAT64 entries.
-      '';
-    };
     prefix = mkOption {
       type = types.str;
       default = "64:ff9b::/96";
@@ -38,19 +31,14 @@ in
   };
 
   config = mkIf (cfg.enable && cfg.nat64.enable) {
-    systemd.network.config = {
+    systemd.network.config.networkConfig.IPv6Forwarding = true;
-      networkConfig = {
-        IPv6Forwarding = true;
-        ManageForeignRoutes = false;
-      };
-    };
 
     systemd.network.networks."70-nat64" = {
       matchConfig.Name = "nat64";
       routes = [
         {
           Destination = cfg.nat64.prefix;
-          Table = cfg.nat64.table;
+          Table = config.networking.routingTables.nat64;
         }
         { Destination = cfg.nat64.dynamicPool; }
       ];
@@ -59,7 +47,7 @@ in
     };
 
     systemd.services.enthalpy-nat64 = {
-      serviceConfig = {
+      serviceConfig = mylib.misc.serviceHardened // {
         Type = "forking";
         Restart = "on-failure";
         RestartSec = 5;
@@ -73,25 +61,19 @@ in
         ''}";
         CapabilityBoundingSet = [ "CAP_NET_ADMIN" ];
         AmbientCapabilities = [ "CAP_NET_ADMIN" ];
-        ProtectSystem = "full";
+        PrivateDevices = false;
-        ProtectHome = "yes";
-        ProtectKernelTunables = true;
-        ProtectControlGroups = true;
-        PrivateTmp = true;
-        SystemCallFilter = "~@cpu-emulation @debug @keyring @module @mount @obsolete @raw-io";
-        MemoryDenyWriteExecute = "yes";
       };
-      wants = [ "network.target" ];
+      after = [ "netns-enthalpy.service" ];
-      after = [
+      partOf = [ "netns-enthalpy.service" ];
+      wantedBy = [
+        "multi-user.target"
         "netns-enthalpy.service"
-        "network.target"
       ];
-      requires = [ "netns-enthalpy.service" ];
-      wantedBy = [ "multi-user.target" ];
     };
 
-    networking.nftables.enable = true;
+    networking.nftables = {
-    networking.nftables.tables.enthalpy4 = {
+      enable = true;
+      tables.enthalpy4 = {
         family = "ip";
         content = ''
           chain forward {
@@ -101,4 +83,5 @@ in
         '';
       };
     };
+  };
 }

nixos/modules/services/enthalpy/services.nix

@@ -1,63 +0,0 @@
-# Portions of this file are sourced from
-# https://github.com/NickCao/flakes/blob/3b03efb676ea602575c916b2b8bc9d9cd13b0d85/modules/gravity/default.nix
-{
-  config,
-  lib,
-  ...
-}:
-with lib;
-let
-  cfg = config.services.enthalpy;
-in
-{
-  options.services.enthalpy = {
-    services = mkOption {
-      type = types.attrsOf (
-        types.submodule {
-          options = {
-            overrideStrategy = mkOption {
-              type = types.str;
-              default = "asDropinIfExists";
-            };
-          };
-        }
-      );
-      default = { };
-      description = ''
-        Services that need to run inside the enthalpy network namespace.
-      '';
-    };
-    users = mkOption {
-      type = types.attrsOf (types.submodule { });
-      default = { };
-      description = ''
-        Users utilizing the enthalpy network namespace.
-      '';
-    };
-  };
-
-  config = mkIf cfg.enable (mkMerge [
-    {
-      systemd.services = mapAttrs (_name: value: {
-        inherit (value) overrideStrategy;
-        serviceConfig = {
-          NetworkNamespacePath = "/run/netns/${cfg.netns}";
-          BindReadOnlyPaths = [
-            "/etc/netns/${cfg.netns}/resolv.conf:/etc/resolv.conf:norbind"
-            "/etc/netns/${cfg.netns}/nsswitch.conf:/etc/nsswitch.conf:norbind"
-            "/run/netns-${cfg.netns}/nscd:/run/nscd:norbind"
-          ];
-        };
-        after = [ "netns-enthalpy.service" ];
-        requires = [ "netns-enthalpy.service" ];
-      }) cfg.services;
-
-      services.enthalpy.services = mapAttrs' (
-        name: _value:
-        nameValuePair "user@${toString config.users.users.${name}.uid}" {
-          overrideStrategy = "asDropin";
-        }
-      ) cfg.users;
-    }
-  ]);
-}

nixos/modules/services/enthalpy/srv6.nix

@@ -24,8 +24,11 @@ in
     };
     actions = mkOption {
       type = types.listOf types.str;
-      default = [
+      default =
+        [
           "${cidr.host 1 cfg.srv6.prefix} encap seg6local action End.DT6 table main  dev enthalpy table localsid"
+        ]
+        ++ optionals cfg.nat64.enable [
           "${cidr.host 2 cfg.srv6.prefix} encap seg6local action End.DT6 table nat64 dev enthalpy table localsid"
         ];
       description = ''
@@ -57,27 +60,34 @@ in
       };
     };
 
+    services.enthalpy.exit = {
+      enable = true;
+      prefix = singleton {
+        type = "static";
+        destination = cfg.srv6.prefix;
+        source = cfg.network;
+      };
+    };
+
     systemd.services.enthalpy-srv6 = {
-      path = with pkgs; [ iproute2 ];
+      path = with pkgs; [
+        iproute2
+      ];
+      script = concatMapStringsSep "\n" (p: "ip -6 route add ${p}") cfg.srv6.actions;
+      preStop = concatMapStringsSep "\n" (p: "ip -6 route del ${p}") cfg.srv6.actions;
       serviceConfig = {
         Type = "oneshot";
         RemainAfterExit = true;
-        ExecStartPre = [
-          "${pkgs.iproute2}/bin/ip -n ${cfg.netns} -6 r a ${cfg.srv6.prefix} from ${cfg.network} via fe80::ff:fe00:1 dev enthalpy"
-        ];
-        ExecStart = builtins.map (route: "${pkgs.iproute2}/bin/ip -6 r a ${route}") cfg.srv6.actions;
-        ExecStop = builtins.map (route: "${pkgs.iproute2}/bin/ip -6 r d ${route}") cfg.srv6.actions;
-        ExecStopPost = [
-          "${pkgs.iproute2}/bin/ip -n ${cfg.netns} -6 r d ${cfg.srv6.prefix} from ${cfg.network} via fe80::ff:fe00:1 dev enthalpy"
-        ];
       };
-      after = [
+      after = [ "netns-enthalpy.service" ];
+      partOf = [
+        "netns-enthalpy.service"
+        "enthalpy-exit.service"
+      ];
+      wantedBy = [
+        "multi-user.target"
         "netns-enthalpy.service"
-        "network-online.target"
       ];
-      requires = [ "netns-enthalpy.service" ];
-      wants = [ "network-online.target" ];
-      wantedBy = [ "multi-user.target" ];
     };
   };
 }