dhcpv4: rework lease expire handling logic

Don't rely on incoming DHCPv4 messages to trigger the lease expire
detection logic but rather use a periodic timer which checks every
second if a lease is expired

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 12e63361a81a113ebb0d82859f212f7e5868e5d3..9e862ca33ba6e7e080f5103cab212dfbc7f24fb0 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -37,6 +37,7 @@
 
 static int setup_dhcpv4_addresses(struct interface *iface);
 static void update_static_assignments(struct interface *iface);
+static void valid_until_cb(struct uloop_timeout *event);
 static void free_dhcpv4_assignment(struct dhcpv4_assignment *a);
 static void dhcpv4_fr_start(struct dhcpv4_assignment *a);
 static void dhcpv4_fr_stop(struct dhcpv4_assignment *a);
@@ -46,6 +47,8 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
                enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr,
                uint32_t *leasetime, const char *hostname, const size_t hostname_len,
                const bool accept_fr_nonce, bool *incl_fr_opt, uint32_t *fr_serverid);
+
+static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
 static uint32_t serial = 0;
 
 struct odhcpd_ref_ip {
@@ -57,6 +60,7 @@ struct odhcpd_ref_ip {
 /* Create socket and register events */
 int init_dhcpv4(void)
 {
+       uloop_timeout_set(&valid_until_timeout, 1000);
        return 0;
 }
 
@@ -323,6 +327,23 @@ static bool leases_require_fr(struct interface *iface, struct odhcpd_ipaddr *add
        return fr_ip ? true : false;
 }
 
+static void valid_until_cb(struct uloop_timeout *event)
+{
+       time_t now = odhcpd_time();
+       struct interface *iface;
+       list_for_each_entry(iface, &interfaces, head) {
+               if (iface->dhcpv4 != MODE_SERVER || iface->dhcpv4_assignments.next == NULL)
+                       continue;
+
+               struct dhcpv4_assignment *a, *n;
+               list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) {
+                       if (!INFINITE_VALID(a->valid_until) && a->valid_until < now)
+                               free_dhcpv4_assignment(a);
+               }
+       }
+       uloop_timeout_set(event, 1000);
+}
+
 void dhcpv4_addr_update(struct interface *iface)
 {
        if (iface->dhcpv4 == MODE_DISABLED)
@@ -910,14 +931,13 @@ static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
        struct dhcpv4_assignment *lease = NULL;
        time_t now = odhcpd_time();
 
-       struct dhcpv4_assignment *c, *n, *a = NULL;
-       list_for_each_entry_safe(c, n, &iface->dhcpv4_assignments, head) {
+       struct dhcpv4_assignment *c, *a = NULL;
+       list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
                if (!memcmp(c->hwaddr, mac, 6)) {
                        a = c;
                        if (c->addr == reqaddr.s_addr)
                                break;
-               } else if (!INFINITE_VALID(c->valid_until) && c->valid_until < now)
-                       free_dhcpv4_assignment(c);
+               }
        }
 
        if (a && (a->flags & OAF_BOUND) && a->fr_ip) {