/*
* Russ Dill <Russ.Dill@asu.edu> July 2001
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include "common.h"
#include "dhcpd.h"
uint32_t addr;
struct dyn_lease *oldest_lease = NULL;
- addr = server_config.start_ip; /* addr is in host order here */
- for (; addr <= server_config.end_ip; addr++) {
+#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
+ uint32_t stop;
+ unsigned i, hash;
+
+ /* hash hwaddr: use the SDBM hashing algorithm. Seems to give good
+ * dispersal even with similarly-valued "strings".
+ */
+ hash = 0;
+ for (i = 0; i < 6; i++)
+ hash += safe_mac[i] + (hash << 6) + (hash << 16) - hash;
+
+ /* pick a seed based on hwaddr then iterate until we find a free address. */
+ addr = server_config.start_ip
+ + (hash % (1 + server_config.end_ip - server_config.start_ip));
+ stop = addr;
+#else
+ addr = server_config.start_ip;
+#define stop (server_config.end_ip + 1)
+#endif
+ do {
uint32_t nip;
struct dyn_lease *lease;
/* ie, 192.168.55.0 */
if ((addr & 0xff) == 0)
- continue;
+ goto next_addr;
/* ie, 192.168.55.255 */
if ((addr & 0xff) == 0xff)
- continue;
+ goto next_addr;
nip = htonl(addr);
+ /* skip our own address */
+ if (nip == server_config.server_nip)
+ goto next_addr;
/* is this a static lease addr? */
if (is_nip_reserved(server_config.static_leases, nip))
- continue;
+ goto next_addr;
lease = find_lease_by_nip(nip);
if (!lease) {
if (!oldest_lease || lease->expires < oldest_lease->expires)
oldest_lease = lease;
}
- }
+
+ next_addr:
+ addr++;
+#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
+ if (addr > server_config.end_ip)
+ addr = server_config.start_ip;
+#endif
+ } while (addr != stop);
if (oldest_lease
&& is_expired_lease(oldest_lease)