addr_pton_cidr
int addr_pton_cidr(const char *p, struct xaddr *n, u_int *l);
r = addr_pton_cidr(cp, &match_addr, &masklen);
r = addr_pton_cidr(cp, &match_addr, &masklen);
if (addr_pton_cidr(host, &addr, &masklen) != 0) {