ipsec_getpolicybysock
sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND,
sp = ipsec_getpolicybysock(m, dir, inp, &error);
static struct secpolicy *ipsec_getpolicybysock(struct mbuf *, u_int,
sp = ipsec_getpolicybysock(m, dir, inp, error);