gre_ip_output
if (m == NULL || gre_ip_output(&sc->sc_tunnel, m) != 0) {
if (gre_ip_output(&sc->sc_tunnel, m) != 0) {
if (m == NULL || gre_ip_output(&sc->sc_tunnel, m) != 0) {
gre_ip_output(const struct gre_tunnel *, struct mbuf *);
gre_ip_output(&sc->sc_tunnel, m);
if (m == NULL || gre_ip_output(&sc->sc_tunnel, m) != 0) {
gre_ip_output(&sc->sc_tunnel, m);
if (gre_ip_output(&sc->sc_tunnel, m) != 0) {