netdev: Let netdev_get_in4(), netdev_get_in6() take null pointer argument.

Some callers want to just test whether the device has an address assigned
and don't care about the particular address, so this simplifies those
callers slightly.

diff --git a/lib/netdev.c b/lib/netdev.c
index 0bcef67..0cd3e6d 100644 (file)
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -530,13 +530,15 @@ netdev_get_features(const struct netdev *netdev)
     return netdev->features;
 }
 
-/* If 'netdev' has an assigned IPv4 address, sets '*in4' to that address and
- * returns true.  Otherwise, returns false. */
+/* If 'netdev' has an assigned IPv4 address, sets '*in4' to that address (if
+ * 'in4' is non-null) and returns true.  Otherwise, returns false. */
 bool
 netdev_get_in4(const struct netdev *netdev, struct in_addr *in4)
 {
-    *in4 = netdev->in4;
-    return in4->s_addr != INADDR_ANY;
+    if (in4) {
+        *in4 = netdev->in4; 
+    }
+    return netdev->in4.s_addr != INADDR_ANY;
 }
 
 static void
@@ -608,13 +610,15 @@ netdev_add_router(struct netdev *netdev, struct in_addr router)
     return error;
 }
 
-/* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address and
- * returns true.  Otherwise, returns false. */
+/* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address (if
+ * 'in6' is non-null) and returns true.  Otherwise, returns false. */
 bool
 netdev_get_in6(const struct netdev *netdev, struct in6_addr *in6)
 {
-    *in6 = netdev->in6;
-    return memcmp(in6, &in6addr_any, sizeof *in6) != 0;
+    if (in6) {
+        *in6 = netdev->in6;
+    }
+    return memcmp(&netdev->in6, &in6addr_any, sizeof netdev->in6) != 0;
 }
 
 /* Obtains the current flags for 'netdev' and stores them into '*flagsp'.