getprotobyname_r
int getprotobyname_r(const char *, struct protoent *,
PROTO_NORMAL(getprotobyname_r);
DEF_WEAK(getprotobyname_r);
if (getprotobyname_r(name, &proto, &_protoent_data) != 0)
r = getprotobyname_r("vrrp", &protoent, &protoent_data);
r = getprotobyname_r("nonexistent", &protoent, &protoent_data);
r = getprotobyname_r("", &protoent, &protoent_data);