add_nat
int add_nat(u_int32_t, struct sockaddr *, int, struct sockaddr *, u_int16_t,
if (add_nat(s->id, client_sa, getrtable(), server_sa,
if (add_nat(s->id, server_sa, s->client_rd, client_sa,
if (add_nat(s->id, server_sa, s->client_rd, client_sa,