applymask
applymask(addr, &tmp, mask);
void applymask(struct bgpd_addr *, const struct bgpd_addr *, int);
applymask(&masked, key, i);
applymask(&masked, key, i);
applymask(&netmask, &netmask, kf->prefixlen);
applymask(&masked, a, p->conf.remote_masklen);