add systemd service file

index 57ea99d..5adb223 100644
@@ -13,6 +13,8 @@ AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([-Wall foreign subdir-objects
         tar-pax no-dist-gzip dist-bzip2 1.6])
 
+AC_PATH_TOOL(PKGCONFIG, pkg-config)
+
 dnl kernel style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 

@@ -112,6 +114,36 @@ AC_TYPE_UINT16_T
 AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 
+AC_ARG_WITH(systemd, [  --with-systemd          set directory for systemd service files],
+        [systemd_unitdir="$withval"; with_systemd=yes],
+        [systemd_unitdir=""; with_systemd=no])
+AC_SUBST(systemd_unitdir)
+
+AC_ARG_WITH(systemdutildir, [  --with-systemdutildir   set directory for systemd helper scripts],
+        [systemd_utildir="$withval"], [systemd_utildir=""])
+AC_SUBST(systemd_utildir)
+
+AM_CONDITIONAL([INSTALL_SYSTEMD], [test "x$with_systemd" != xno])
+AM_COND_IF([INSTALL_SYSTEMD],
+       [AS_IF([test "x$PKGCONFIG" = "x"],
+             [AC_MSG_ERROR(Need pkg-config to enable systemd support.)],
+
+             [AC_MSG_CHECKING(for systemd)
+              AS_IF([$PKGCONFIG --exists systemd],
+                    [AC_MSG_RESULT(yes)
+                     AS_IF([$PKGCONFIG --exists systemd],
+                           [AS_IF([test "x$systemd_unit_dir" = "x"],
+                                  [ systemd_unitdir="`$PKGCONFIG --variable=systemdsystemunitdir systemd`"])
+                            AS_IF([test "x$systemd_util_dir" = "x"],
+                                  [ systemd_utildir="`$PKGCONFIG --variable=systemdutildir systemd`"])
+                           ])
+                    ]
+                    [AC_MSG_RESULT(no)])
+             ]
+
+       )]
+)
+
 # Checks for library functions.
 AC_CHECK_FUNCS([memmove memset strchr strdup strerror strtoull])
 

@@ -124,10 +156,12 @@ AC_CONFIG_FILES([					\
 		doc/Makefile				\
 		files/Makefile				\
 		files/nftables/Makefile			\
+		files/systemd/Makefile			\
 		])
 AC_OUTPUT
 
 echo "
 nft configuration:
   cli support:			${with_cli}
+  systemd support:		${with_systemd}
   enable debugging:		${with_debug}"

index a8394c0..4dc0027 100644
@@ -1 +1,2 @@
-SUBDIRS = nftables
+SUBDIRS =	nftables	\
+					systemd

new file mode 100644
index 0000000..e69de29

new file mode 100644
index 0000000..c0a56c8
@@ -0,0 +1,12 @@
+
+if INSTALL_SYSTEMD
+systemd_unit_DATA = nftables.service
+
+systemd_scriptsdir = ${systemd_utildir}/scripts
+systemd_scripts_SCRIPTS = nftables-reload
+
+install-data-hook:
+	${SED} -i 's|@sbindir[@]|${sbindir}/|g;s|@sysconfdir[@]|${sysconfdir}/|g;s|@systemd_scriptsdir[@]|${systemd_scriptsdir}/|g' \
+		${DESTDIR}${systemd_scriptsdir}/nftables-reload \
+		${DESTDIR}${systemd_unitdir}/nftables.service
+endif

new file mode 100755
index 0000000..0fcc2ad
@@ -0,0 +1,16 @@
+#!/bin/sh
+
+set -e
+
+if [ ! -f @[email protected] ]
+then
+  echo "/etc/nftables.conf does not exist" >&2
+  exit 1
+fi
+
+tmp=${TMPDIR-/tmp}
+rules=`mktemp "$tmp/nftables.XXXXXXX"`
+trap "rm -f $tmpfile" 0 1 2 3 15
+echo "flush ruleset" > "$rules"
+cat @[email protected] >> "$rules"
+@sbindir@nft -f "$rules"

new file mode 100644
index 0000000..f958bfc
@@ -0,0 +1,12 @@
+[Unit]
+Description=nftables
+Documentation=man:nft(8)
+
+[Service]
+RemainAfterExit=yes
+ExecStart=@sbindir@nft -I /etc/nftables -f /etc/nftables.conf
+ExecStop=@sbindir@nft flush ruleset
+ExecReload=@systemd_scriptsdir@nftables-reload
+
+[Install]
+WantedBy=multi-user.target