xdr_inaddr_decode
if (xdr_inaddr_decode(&recv_head, &gateip)) {
if (xdr_inaddr_decode(&recv_head, serv_addr)) {
int xdr_inaddr_decode(char **p, struct in_addr *ia);
struct mbuf *xdr_inaddr_decode(struct mbuf *, struct in_addr *);
m = xdr_inaddr_decode(m, gw_ip);
m = xdr_inaddr_decode(m, &inaddr);