dhcp: Invalidate and Release on Network Removal

When removing a network DHCP configuration, invalidate the DHCP
configuration in addition to releasing it.

This addresses a case in which a lower-level network event (e.g. Wi-Fi
disassociation triggered by the driver due to low signal strength)
causes a service disconnect not triggered by connman but then is
recovered BY connman to reuse the prior DHCP lease configuration but
not actually assign it by simply invalidating the old lease
configuration when connman removes the prior network.

1 files changed, 23 insertions, 6 deletions

diff --git a/src/dhcp.c b/src/dhcp.c
index f1e30967..b391ddf6 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -59,12 +59,29 @@ static void dhcp_free(struct connman_dhcp *dhcp)
 	dhcp->pac = NULL;
 }
 
-static void dhcp_invalid(struct connman_dhcp *dhcp)
+/**
+ * dhcp_invalidate: Invalidate an existing DHCP lease
+ * @dhcp: pointer to the DHCP lease to invalidate.
+ * @callback: flag indicating whether or not to invoke the client callback
+ *            if present.
+ *
+ * Invalidates an existing DHCP lease, optionally invoking the client
+ * callback. The caller may wish to avoid the client callback invocation
+ * when the invocation of that callback might otherwise unnecessarily upset
+ * service state due to the IP configuration change implied by this
+ * invalidation.
+ */
+static void dhcp_invalidate(struct connman_dhcp *dhcp, connman_bool_t callback)
 {
 	struct connman_service *service;
 	struct connman_ipconfig *ipconfig;
 	int i;
 
+	DBG("dhcp %p callback %u", dhcp, callback);
+
+	if (dhcp == NULL)
+		return;
+
 	service = __connman_service_lookup_from_network(dhcp->network);
 	if (service == NULL)
 		return;
@@ -89,7 +106,7 @@ static void dhcp_invalid(struct connman_dhcp *dhcp)
 	__connman_ipconfig_set_gateway(ipconfig, NULL);
 	__connman_ipconfig_set_prefixlen(ipconfig, 0);
 
-	if (dhcp->callback != NULL)
+	if (dhcp->callback != NULL && callback)
 		dhcp->callback(dhcp->network, FALSE);
 
 	dhcp_free(dhcp);
@@ -107,7 +124,7 @@ static void no_lease_cb(GDHCPClient *dhcp_client, gpointer user_data)
 
 	DBG("No lease available");
 
-	dhcp_invalid(dhcp);
+	dhcp_invalidate(dhcp, TRUE);
 }
 
 static void lease_lost_cb(GDHCPClient *dhcp_client, gpointer user_data)
@@ -116,7 +133,7 @@ static void lease_lost_cb(GDHCPClient *dhcp_client, gpointer user_data)
 
 	DBG("Lease lost");
 
-	dhcp_invalid(dhcp);
+	dhcp_invalidate(dhcp, TRUE);
 }
 
 static void ipv4ll_lost_cb(GDHCPClient *dhcp_client, gpointer user_data)
@@ -125,7 +142,7 @@ static void ipv4ll_lost_cb(GDHCPClient *dhcp_client, gpointer user_data)
 
 	DBG("Lease lost");
 
-	dhcp_invalid(dhcp);
+	dhcp_invalidate(dhcp, TRUE);
 }
 
 
@@ -412,9 +429,9 @@ static void remove_network(gpointer user_data)
 
 	DBG("dhcp %p", dhcp);
 
+	dhcp_invalidate(dhcp, FALSE);
 	dhcp_release(dhcp);
 
-	dhcp_free(dhcp);
 	g_free(dhcp);
 }