Added a systemd service file

Makefile

@@ -5,11 +5,14 @@ FIREWALL_ETC_DIR=/etc/lfirewall
 FIREWALL_CONF=lfirewall.conf
 PREFIX=
 INSTALL_DIR=$(PREFIX)/sbin
+SYSTEMD_INSTALL_DIR=$(PREFIX)/etc/systemd/system
+SERVICE_FILE=lfirewall.service
+SYSTEMD_SERVICE_FILE=$(SYSTEMD_INSTALL_DIR)/$(SERVICE_FILE)
 
 #SysVinit installation dir
 #INSTALL_DIR=/etc/init.d
 
-firewall: $(INSTALL_DIR)/lfirewall config
+firewall: $(INSTALL_DIR)/lfirewall config $(SYSTEMD_SERVICE_FILE)
 
 config: 
 	$(MKDIR) -p $(FIREWALL_ETC_DIR)
@@ -18,3 +21,6 @@ config:
 $(INSTALL_DIR)/lfirewall: scripts/lfirewall
 	$(CP) $< $@
 
+$(SYSTEMD_SERVICE_FILE): systemd/$(SERVICE_FILE)
+	$(CP) $< $@
+	

systemd/lfirewall.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Light Firewall
+
+[Service]
+Type=oneshot
+ExecStart=/sbin/lfirewall start
+ExecStop=/sbin/lfirewall clear
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target