pppox_proto
static const struct pppox_proto pppoe_proto = {
static const struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
int register_pppox_proto(int proto_num, const struct pppox_proto *pp)
static const struct pppox_proto pppox_pptp_proto = {
extern int register_pppox_proto(int proto_num, const struct pppox_proto *pp);
static const struct pppox_proto pppol2tp_proto = {