sd-dhcp6: ensure canceling lease timers and refactor setting lease

Factor our common code to set/clear the client lease.
Resetting the lease involves canceling old timers.

Also, most importantly, when resetting the lease
in client_receive_advertise(), ensure to cancel
the timers too. It is not immediately clear, why
at that point no timers would be pending.

The lease-unref from sd_dhcp6_client_unref() can
be omited, because of the preceeding client_reset()
call.

1 files changed, 11 insertions, 13 deletions

diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 5489c77864..59d80bc38a 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -266,13 +266,18 @@ static void client_notify(sd_dhcp6_client *client, int event) {
                 client->cb(client, event, client->userdata);
 }
 
-static int client_reset(sd_dhcp6_client *client) {
-        assert_return(client, -EINVAL);
-
+static void client_set_lease(sd_dhcp6_client *client, sd_dhcp6_lease *lease) {
         if (client->lease) {
                 dhcp6_lease_clear_timers(&client->lease->ia);
-                client->lease = sd_dhcp6_lease_unref(client->lease);
+                sd_dhcp6_lease_unref(client->lease);
         }
+        client->lease = lease;
+}
+
+static int client_reset(sd_dhcp6_client *client) {
+        assert_return(client, -EINVAL);
+
+        client_set_lease(client, NULL);
 
         client->receive_message =
                 sd_event_source_unref(client->receive_message);
@@ -826,12 +831,7 @@ static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, si
                         return 0;
         }
 
-        if (client->lease) {
-                dhcp6_lease_clear_timers(&client->lease->ia);
-                client->lease = sd_dhcp6_lease_unref(client->lease);
-        }
-
-        client->lease = lease;
+        client_set_lease(client, lease);
         lease = NULL;
 
         return DHCP6_STATE_BOUND;
@@ -860,8 +860,7 @@ static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *adver
         r = dhcp6_lease_get_preference(client->lease, &pref_lease);
 
         if (r < 0 || pref_advertise > pref_lease) {
-                sd_dhcp6_lease_unref(client->lease);
-                client->lease = lease;
+                client_set_lease(client, lease);
                 lease = NULL;
                 r = 0;
         }
@@ -1233,7 +1232,6 @@ sd_dhcp6_client *sd_dhcp6_client_unref(sd_dhcp6_client *client) {
         client_reset(client);
 
         sd_dhcp6_client_detach_event(client);
-        sd_dhcp6_lease_unref(client->lease);
 
         free(client->req_opts);
         free(client);