-/*
- * leases.c -- tools to manage DHCP leases
+/* vi: set sw=4 ts=4: */
+/*
+ * leases.c -- tools to manage DHCP leases
* Russ Dill <Russ.Dill@asu.edu> July 2001
*/
-#include <time.h>
-#include <string.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-
-#include "dhcpd.h"
-#include "files.h"
-#include "options.h"
-#include "leases.h"
-#include "arpping.h"
#include "common.h"
+#include "dhcpd.h"
-unsigned char blank_chaddr[] = {[0 ... 15] = 0};
+/* 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);
+ 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]);
+ }
+ return oldest;
+}
+
/* clear every lease out that chaddr OR yiaddr matches and is nonzero */
-void clear_lease(u_int8_t *chaddr, u_int32_t yiaddr)
+static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
{
- unsigned int i, j;
-
- for (j = 0; j < 16 && !chaddr[j]; j++);
-
+ unsigned i, j;
+
+ for (j = 0; j < 16 && !chaddr[j]; j++)
+ continue;
+
for (i = 0; i < server_config.max_leases; i++)
- if ((j != 16 && !memcmp(leases[i].chaddr, chaddr, 16)) ||
- (yiaddr && leases[i].yiaddr == yiaddr)) {
- memset(&(leases[i]), 0, sizeof(struct dhcpOfferedAddr));
+ 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 *add_lease(u_int8_t *chaddr, u_int32_t yiaddr, unsigned long lease)
+struct dhcpOfferedAddr *add_lease(const uint8_t *chaddr, uint32_t yiaddr, unsigned long lease)
{
struct dhcpOfferedAddr *oldest;
-
+
/* clean out any old ones */
clear_lease(chaddr, yiaddr);
-
+
oldest = oldest_expired_lease();
-
+
if (oldest) {
memcpy(oldest->chaddr, chaddr, 16);
oldest->yiaddr = yiaddr;
oldest->expires = time(0) + lease;
}
-
+
return oldest;
}
int lease_expired(struct dhcpOfferedAddr *lease)
{
return (lease->expires < (unsigned long) time(0));
-}
-
-
-/* Find the oldest expired lease, NULL if there are no expired leases */
-struct dhcpOfferedAddr *oldest_expired_lease(void)
-{
- struct dhcpOfferedAddr *oldest = NULL;
- unsigned long oldest_lease = time(0);
- unsigned int i;
-
-
- for (i = 0; i < server_config.max_leases; i++)
- if (oldest_lease > leases[i].expires) {
- oldest_lease = leases[i].expires;
- oldest = &(leases[i]);
- }
- return oldest;
-
}
/* Find the first lease that matches chaddr, NULL if no match */
-struct dhcpOfferedAddr *find_lease_by_chaddr(u_int8_t *chaddr)
+struct dhcpOfferedAddr *find_lease_by_chaddr(const uint8_t *chaddr)
{
- unsigned int i;
+ unsigned i;
for (i = 0; i < server_config.max_leases; i++)
- if (!memcmp(leases[i].chaddr, chaddr, 16)) return &(leases[i]);
-
+ if (!memcmp(leases[i].chaddr, chaddr, 16))
+ return &(leases[i]);
+
return NULL;
}
/* Find the first lease that matches yiaddr, NULL is no match */
-struct dhcpOfferedAddr *find_lease_by_yiaddr(u_int32_t yiaddr)
+struct dhcpOfferedAddr *find_lease_by_yiaddr(uint32_t yiaddr)
{
- unsigned int i;
+ unsigned i;
for (i = 0; i < server_config.max_leases; i++)
- if (leases[i].yiaddr == yiaddr) return &(leases[i]);
-
+ if (leases[i].yiaddr == yiaddr)
+ return &(leases[i]);
+
return NULL;
}
/* check is an IP is taken, if it is, add it to the lease table */
-static int check_ip(u_int32_t addr)
+static int nobody_responds_to_arp(uint32_t addr)
{
+ /* 16 zero bytes */
+ static const uint8_t blank_chaddr[16] = { 0 };
+ /* = { 0 } helps gcc to put it in rodata, not bss */
+
struct in_addr temp;
+ int r;
+
+ r = arpping(addr, server_config.server, server_config.arp, server_config.interface);
+ if (r)
+ return r;
- if (arpping(addr, server_config.server, server_config.arp, server_config.interface) == 0) {
- temp.s_addr = addr;
- LOG(LOG_INFO, "%s belongs to someone, reserving it for %ld seconds",
- inet_ntoa(temp), server_config.conflict_time);
- add_lease(blank_chaddr, addr, server_config.conflict_time);
- return 1;
- } else return 0;
+ temp.s_addr = addr;
+ bb_info_msg("%s belongs to someone, reserving it for %u seconds",
+ inet_ntoa(temp), (unsigned)server_config.conflict_time);
+ add_lease(blank_chaddr, addr, server_config.conflict_time);
+ return 0;
}
-/* find an assignable address, it check_expired is true, we check all the expired leases as well.
+/* 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... */
-u_int32_t find_address(int check_expired)
+uint32_t find_address(int check_expired)
{
- u_int32_t addr, ret;
- struct dhcpOfferedAddr *lease = NULL;
-
- addr = ntohl(server_config.start); /* addr is in host order here */
- for (;addr <= ntohl(server_config.end); addr++) {
+ uint32_t addr, ret;
+ struct dhcpOfferedAddr *lease = NULL;
+ addr = server_config.start_ip; /* addr is in host order here */
+ for (; addr <= server_config.end_ip; addr++) {
/* ie, 192.168.55.0 */
- if (!(addr & 0xFF)) continue;
-
+ if (!(addr & 0xFF))
+ continue;
/* ie, 192.168.55.255 */
- if ((addr & 0xFF) == 0xFF) continue;
-
- /* lease is not taken */
+ if ((addr & 0xFF) == 0xFF)
+ continue;
+ /* Only do if it isn't assigned as a static lease */
ret = htonl(addr);
- if ((!(lease = find_lease_by_yiaddr(ret)) ||
-
- /* or it expired and we are checking for expired leases */
- (check_expired && lease_expired(lease))) &&
-
- /* and it isn't on the network */
- !check_ip(ret)) {
- return ret;
- break;
+ 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;
+ }
}
}
return 0;
projects / oweals / busybox.git / blobdiff