libreswan: add package and service to nixos

1 files changed, 126 insertions, 0 deletions

diff --git a/nixos/modules/services/networking/libreswan.nix b/nixos/modules/services/networking/libreswan.nix
new file mode 100644
index 00000000000..3866b216f8e
--- /dev/null
+++ b/nixos/modules/services/networking/libreswan.nix
@@ -0,0 +1,126 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.libreswan;
+
+  libexec = "${pkgs.libreswan}/libexec/ipsec";
+  ipsec = "${pkgs.libreswan}/sbin/ipsec";
+
+  trim = chars: str: let
+      nonchars = filter (x : !(elem x.value chars))
+                  (imap (i: v: {ind = (sub i 1); value = v;}) (stringToCharacters str));
+    in
+      if length nonchars == 0 then ""
+      else substring (head nonchars).ind (add 1 (sub (last nonchars).ind (head nonchars).ind)) str;
+  indent = str: concatStrings (concatMap (s: ["  " (trim [" " "\t"] s) "\n"]) (splitString "\n" str));
+  configText = indent (toString cfg.configSetup);
+  connectionText = concatStrings (mapAttrsToList (n: v: 
+    ''
+      conn ${n}
+      ${indent v}
+
+    '') cfg.connections);
+  configFile = pkgs.writeText "ipsec.conf"
+    ''
+      config setup
+      ${configText}
+      
+      ${connectionText}
+    '';
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.libreswan = {
+
+      enable = mkEnableOption "libreswan ipsec service";
+
+      configSetup = mkOption {
+        type = types.lines;
+        default = ''
+            protostack=netkey
+            nat_traversal=yes
+            virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:25.0.0.0/8,%v4:100.64.0.0/10,%v6:fd00::/8,%v6:fe80::/10
+        '';
+        example = ''
+            secretsfile=/root/ipsec.secrets
+            protostack=netkey
+            nat_traversal=yes
+            virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:25.0.0.0/8,%v4:100.64.0.0/10,%v6:fd00::/8,%v6:fe80::/10
+        '';
+        description = "Options to go in the 'config setup' section of the libreswan ipsec configuration";
+      };
+
+      connections = mkOption {
+        type = types.attrsOf types.lines;
+        default = {};
+        example = {
+          myconnection = ''
+            auto=add
+            left=%defaultroute
+            leftid=@user
+
+            right=my.vpn.com
+
+            ikev2=no
+            ikelifetime=8h
+          '';
+        };
+        description = "A set of connections to define for the libreswan ipsec service";
+      };
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    environment.systemPackages = [ pkgs.libreswan pkgs.iproute ];
+
+    systemd.services.ipsec = {
+      description = "Internet Key Exchange (IKE) Protocol Daemon for IPsec";
+      path = [
+        "${pkgs.libreswan}"
+        "${pkgs.iproute}"
+        "${pkgs.procps}"
+      ];
+
+      wants = [ "network-online.target" ];
+      after = [ "network-online.target" ];
+      wantedBy = [ "multi-user.target" ];
+
+      serviceConfig = {
+        Type = "simple";
+        Restart = "always";
+        EnvironmentFile = "${pkgs.libreswan}/etc/sysconfig/pluto";
+        ExecStartPre = [
+          "${libexec}/addconn --config ${configFile} --checkconfig"
+          "${libexec}/_stackmanager start"
+          "${ipsec} --checknss"
+          "${ipsec} --checknflog"
+        ];
+        ExecStart = "${libexec}/pluto --config ${configFile} --nofork \$PLUTO_OPTIONS";
+        ExecStop = "${libexec}/whack --shutdown";
+        ExecStopPost = [
+          "${pkgs.iproute}/bin/ip xfrm policy flush"
+          "${pkgs.iproute}/bin/ip xfrm state flush"
+          "${ipsec} --stopnflog"
+        ];
+        ExecReload = "${libexec}/whack --listen";
+      };
+
+    };
+
+  };
+
+}