1 files changed, 46 insertions, 33 deletions

diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c
index a981db0d7..3044c2040 100644
--- a/networking/udhcp/leases.c
+++ b/networking/udhcp/leases.c
@@ -13,21 +13,23 @@
 /* Find the oldest expired lease, NULL if there are no expired leases */
 static struct dhcpOfferedAddr *oldest_expired_lease(void)
 {
-        struct dhcpOfferedAddr *oldest = NULL;
-// TODO: use monotonic_sec()
-        unsigned long oldest_lease = time(0);
+        struct dhcpOfferedAddr *oldest_lease = NULL;
+        leasetime_t oldest_time = time(NULL);
         unsigned i;
 
-        for (i = 0; i < server_config.max_leases; i++)
-                if (oldest_lease > leases[i].expires) {
-                        oldest_lease = leases[i].expires;
-                        oldest = &(leases[i]);
+        /* Unexpired leases have leases[i].expires >= current time
+         * and therefore can't ever match */
+        for (i = 0; i < server_config.max_leases; i++) {
+                if (leases[i].expires < oldest_time) {
+                        oldest_time = leases[i].expires;
+                        oldest_lease = &(leases[i]);
                 }
-        return oldest;
+        }
+        return oldest_lease;
 }
 
 
-/* clear every lease out that chaddr OR yiaddr matches and is nonzero */
+/* Clear every lease out that chaddr OR yiaddr matches and is nonzero */
 static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
 {
         unsigned i, j;
@@ -35,17 +37,18 @@ static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
         for (j = 0; j < 16 && !chaddr[j]; j++)
                 continue;
 
-        for (i = 0; i < server_config.max_leases; i++)
+        for (i = 0; i < server_config.max_leases; i++) {
                 if ((j != 16 && memcmp(leases[i].chaddr, chaddr, 16) == 0)
                  || (yiaddr && leases[i].yiaddr == yiaddr)
                 ) {
                         memset(&(leases[i]), 0, sizeof(leases[i]));
                 }
+        }
 }
 
 
-/* add a lease into the table, clearing out any old ones */
-struct dhcpOfferedAddr* FAST_FUNC add_lease(const uint8_t *chaddr, uint32_t yiaddr, unsigned long lease)
+/* Add a lease into the table, clearing out any old ones */
+struct dhcpOfferedAddr* FAST_FUNC add_lease(const uint8_t *chaddr, uint32_t yiaddr, leasetime_t leasetime)
 {
         struct dhcpOfferedAddr *oldest;
 
@@ -57,17 +60,17 @@ struct dhcpOfferedAddr* FAST_FUNC add_lease(const uint8_t *chaddr, uint32_t yiad
         if (oldest) {
                 memcpy(oldest->chaddr, chaddr, 16);
                 oldest->yiaddr = yiaddr;
-                oldest->expires = time(0) + lease;
+                oldest->expires = time(NULL) + leasetime;
         }
 
         return oldest;
 }
 
 
-/* true if a lease has expired */
+/* True if a lease has expired */
 int FAST_FUNC lease_expired(struct dhcpOfferedAddr *lease)
 {
-        return (lease->expires < (unsigned long) time(0));
+        return (lease->expires < (leasetime_t) time(NULL));
 }
 
 
@@ -119,33 +122,43 @@ static int nobody_responds_to_arp(uint32_t addr)
 }
 
 
-/* find an assignable address, if check_expired is true, we check all the expired leases as well.
- * Maybe this should try expired leases by age... */
-uint32_t FAST_FUNC find_address(int check_expired)
+/* Find a new usable (we think) address. */
+uint32_t FAST_FUNC find_free_or_expired_address(void)
 {
-        uint32_t addr, ret;
-        struct dhcpOfferedAddr *lease = NULL;
+        uint32_t addr;
+        struct dhcpOfferedAddr *oldest_lease = NULL;
 
         addr = server_config.start_ip; /* addr is in host order here */
         for (; addr <= server_config.end_ip; addr++) {
+                uint32_t net_addr;
+                struct dhcpOfferedAddr *lease;
+
                 /* ie, 192.168.55.0 */
-                if (!(addr & 0xFF))
+                if ((addr & 0xff) == 0)
                         continue;
                 /* ie, 192.168.55.255 */
-                if ((addr & 0xFF) == 0xFF)
+                if ((addr & 0xff) == 0xff)
                         continue;
-                /* Only do if it isn't assigned as a static lease */
-                ret = htonl(addr);
-                if (!reservedIp(server_config.static_leases, ret)) {
-                        /* lease is not taken */
-                        lease = find_lease_by_yiaddr(ret);
-                        /* no lease or it expired and we are checking for expired leases */
-                        if ((!lease || (check_expired && lease_expired(lease)))
-                         && nobody_responds_to_arp(ret) /* it isn't used on the network */
-                        ) {
-                                return ret;
-                        }
+                net_addr = htonl(addr);
+                /* addr has a static lease? */
+                if (reservedIp(server_config.static_leases, net_addr))
+                        continue;
+
+                lease = find_lease_by_yiaddr(net_addr);
+                if (!lease) {
+                        if (nobody_responds_to_arp(net_addr))
+                                return net_addr;
+                } else {
+                        if (!oldest_lease || lease->expires < oldest_lease->expires)
+                                oldest_lease = lease;
                 }
         }
+
+        if (oldest_lease && lease_expired(oldest_lease)
+         && nobody_responds_to_arp(oldest_lease->yiaddr)
+        ) {
+                return oldest_lease->yiaddr;
+        }
+
         return 0;
 }