profiles/ds-lite: Connect to Netcologne with PPP DS-Lite

profiles/default.nix

@@ -11,6 +11,7 @@
     ./cybercluster-vm
     ./desktop
     ./dn42-router
+    ./ds-lite
     ./fem-net
     ./firefox
     ./gpg-ssh

profiles/ds-lite/default.nix

@@ -0,0 +1,150 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.profiles.clerie.ds-lite;
+
+
+  dsLiteDhcpcdConfig = ''
+    allowinterfaces ${cfg.wanInterfaceName} ${concatMapStringsSep " " (interface: interface.name) cfg.lanInterfaces}
+
+    option dhcp6_name_servers
+    option dhcp6_aftr_name
+
+    waitip 6
+
+    ipv6only
+    ipv6ra_noautoconf
+    noipv6rs
+
+    interface ${cfg.wanInterfaceName}
+      ipv6ra_autoconf
+      ipv6rs
+      ia_pd 1/::/48 ${concatMapStringsSep " " (interface: "${interface.name}/${toString interface.sla_id}/${toString interface.prefix_len}") cfg.lanInterfaces}
+
+    ${concatMapStrings (interface: ''
+    interface ${interface.name}
+      nolink
+    '') cfg.lanInterfaces}
+  '';
+
+  dsLiteDhcpcdConfigFile = pkgs.writeTextFile {
+    name = "dhcpcd.conf";
+    text = dsLiteDhcpcdConfig;
+  };
+
+  dsLiteDhcpcdHookWrapperFile = pkgs.writeShellScript "ds-lite-dhcpcd-hook-wrapper" ''
+    DS_LITE_WAN_INTERFACE_NAME=${lib.escapeShellArg cfg.wanInterfaceName};
+    export DS_LITE_WAN_INTERFACE_NAME
+    DS_LITE_TUNNEL_INTERFACE_NAME=${lib.escapeShellArg cfg.tunnelInterfaceName};
+    export DS_LITE_TUNNEL_INTERFACE_NAME
+
+    exec ${lib.getExe pkgs.ds-lite-dhcpcd-hook}
+  '';
+
+in {
+
+  options.profiles.clerie.ds-lite = {
+    enable = mkEnableOption "DS-Lite setup";
+    wanInterfaceName = mkOption {
+      type = types.str;
+      description = "Interface with IPv6 connectivity to provider";
+    };
+    tunnelInterfaceName = mkOption {
+      type = types.str;
+      description = "Interface with IPv4 connectivity to provider";
+    };
+    lanInterfaces = mkOption {
+      type = with types; listOf (submodule ({ ... }: {
+        options = {
+          name = mkOption {
+            type = types.str;
+          };
+          sla_id = mkOption {
+            type = types.ints.unsigned;
+          };
+          prefix_len = mkOption {
+            type = types.ints.between 48 128;
+          };
+        };
+      }));
+      default = [];
+      description = "Interfaces to provisn with an IPv6 prefix";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.ds-lite-dhcpcd = {
+      description = "DS-Lite dhcpcd";
+
+      wantedBy = [ "multi-user.target" ];
+
+      environment = {
+      };
+
+      serviceConfig = {
+        Type = "simple";
+        User = "ds-lite";
+        Group = "ds-lite";
+        StateDirectory = "ds-lite-dhcpcd";
+        RuntimeDirectory = "ds-lite-dhcpcd";
+
+        ExecStart = "${pkgs.ds-lite-dhcpcd}/bin/dhcpcd --ipv6only --nobackground --config ${dsLiteDhcpcdConfigFile} --script ${dsLiteDhcpcdHookWrapperFile}";
+
+        Restart = "always";
+        AmbientCapabilities = [
+          "CAP_NET_ADMIN"
+          "CAP_NET_RAW"
+          "CAP_NET_BIND_SERVICE"
+        ];
+        ReadWritePaths = [
+          "/proc/sys/net/ipv6"
+        ];
+        DeviceAllow = "";
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        PrivateDevices = true;
+        PrivateMounts = true;
+        PrivateTmp = true;
+        PrivateUsers = false;
+        ProtectClock = true;
+        ProtectControlGroups = true;
+        ProtectHome = "tmpfs"; # allow exceptions to be added to ReadOnlyPaths, etc.
+        ProtectHostname = true;
+        ProtectKernelLogs = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        ProtectProc = "invisible";
+        ProtectSystem = "strict";
+        RemoveIPC = true;
+        RestrictAddressFamilies = [
+          "AF_UNIX"
+          "AF_INET"
+          "AF_INET6"
+          "AF_NETLINK"
+          "AF_PACKET"
+        ];
+        RestrictNamespaces = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        SystemCallFilter = [
+          "@system-service"
+          "~@keyring"
+          "~@memlock"
+          "~@mount"
+        ];
+        SystemCallArchitectures = "native";
+        UMask = "0027";
+      };
+    };
+
+    users.users.ds-lite = {
+      isSystemUser = true;
+      group = "ds-lite";
+    };
+    users.groups.ds-lite = { };
+  };
+
+}