xfrm4_tunnel_register
int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
err = xfrm4_tunnel_register(&vti_ipip_handler, AF_INET);
err = xfrm4_tunnel_register(&vti_ipip6_handler, AF_INET6);
err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
EXPORT_SYMBOL(xfrm4_tunnel_register);
if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
err = xfrm4_tunnel_register(&xfrmi_ipip_handler, AF_INET);
err = xfrm4_tunnel_register(&xfrmi_ipip6_handler, AF_INET6);