/*
* Given a host-order address, calculate client's default net mask.
* Consult netmasks database to see if net is further subnetted.
* We'll only snag the first netmask that matches our criteria.
* We return the resultant netmask in host order.
*/
void
get_netmask4(const struct in_addr *n_addrp, struct in_addr *s_addrp)
{
struct in_addr hp, tp;
/*
* First check if VLSM is in use.
*/
hp.s_addr = htonl(n_addrp->s_addr);
if (getnetmaskbyaddr(hp, &tp) == 0) {
s_addrp->s_addr = ntohl(tp.s_addr);
return;
}
/*
* Fall back on standard classed networks.
*/
if (IN_CLASSA(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSA_NET;
else if (IN_CLASSB(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSB_NET;
else if (IN_CLASSC(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSC_NET;
else
s_addrp->s_addr = IN_CLASSE_NET;
}
/*
* getnetmaskbyaddr - get entries from network database
*/
int
dogetnetmask(const char **list)
{
int rc = EXC_SUCCESS;
struct in_addr addr, netmask;
if (list == NULL || *list == NULL)
return (EXC_ENUM_NOT_SUPPORTED);
for (; *list != NULL; list++) {
addr.s_addr = htonl(inet_network(*list));
if (addr.s_addr != -1) {
if (getnetmaskbyaddr(addr, &netmask) == 0) {
(void) putnetmask(addr, netmask, stdout);
} else {
rc = EXC_NAME_NOT_FOUND;
}
} else {
rc = EXC_NAME_NOT_FOUND;
}
}
return (rc);
}
