n2n: Add systemd integration (service file + start script)

This allows for configuration of tunnels by putting config files into
/etc/n2n/ similar to what we're used to from /etc/openvpn/

recipes-extra/n2n/n2n/edge.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+source /etc/n2n/edge/$1.conf
+PARAMS="-d $TUN"
+[[ "z$DHCP" = "z1" ]] && PARAMS="$PARAMS -a dhcp:0.0.0.0" || PARAMS="$PARAMS -a static:$ADDRESS"
+PARAMS="$PARAMS -c $COMMUNITY"
+PARAMS="$PARAMS -k $KEY"
+[[ -z "$NETMASK" ]] || PARAMS="$PARAMS -s $NETMASK"
+[[ -z "$MACADDR" ]] || PARAMS="$PARAMS -m $MACADDR"
+PARAMS="$PARAMS -l $SUPERNODE"
+[[ "z$FORWADING" = "z1" ]] && PARAMS="$PARAMS -r"
+[[ -z "$LPORT" ]] || PARAMS="$PARAMS -p $LPORT"
+[[ -z "$MTU" ]] || PARAMS="$PARAMS -M $MTU"
+[[ -z "$TPORT" ]] || PARAMS="$PARAMS -t $TPORT"
+[[ "z$PRESOLV" = "z1" ]] && PARAMS="$PARAMS -b"
+exec /usr/sbin/edge $PARAMS -f
+

recipes-extra/n2n/n2n/n2n-edge@.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=N2N VPN Edge
+After=network.target
+
+[Service]
+Type=simple
+User=root
+ExecStart=/usr/share/n2n/edge.sh %i
+
+[Install]
+WantedBy=multi-user.target
+

recipes-extra/n2n/n2n_git.bb

@@ -6,13 +6,17 @@ DEPENDS = "openssl"
 PV = "2.1.0+git${SRCPV}"
 RRECOMMENDS_${PN} = "kernel-module-tun"
 
-PR="r2"
+PR="r3"
 
 SRC_URI = "git://github.com/ntop/n2n.git;branch=master \
+	   file://edge.sh \
+	   file://n2n-edge@.service \
 	   file://0001-Makefile-Allow-cross-compilation-environment-to-spec.patch"
 SRCREV= "${AUTOREV}"
 S = "${WORKDIR}/git"
 
+inherit systemd
+
 do_compile() {
 	CFLAGS="$CFLAGS $LDFLAGS"
 	oe_runmake 
@@ -20,8 +24,14 @@ do_compile() {
 
 do_install() {
 	oe_runmake install DESTDIR=${D}
+	install -d ${D}/usr/share/n2n
+	install -m 0755 ${WORKDIR}/edge.sh ${D}/usr/share/n2n
+	install -d ${D}${systemd_unitdir}/system
+	install -m 0644 ${WORKDIR}/n2n-edge@.service ${D}${systemd_unitdir}/system
 }
 
+FILES_${PN} += "${systemd_unitdir}"
+
 #PACKAGES += "n2n-edge n2n-supernode"
 #
 #FILES_n2n_edge = "\