networkd: use proper cast to access VTI6 (#4399)

Fixes #4371.

diff --git a/src/network/networkd-netdev-tunnel.c b/src/network/networkd-netdev-tunnel.c
index 77a4734df861fdd807eea5dd4eed22170b428693..9138ee4511cff659927f889a40849e256854f697 100644 (file)
--- a/src/network/networkd-netdev-tunnel.c
+++ b/src/network/networkd-netdev-tunnel.c
@@ -201,12 +201,18 @@ static int netdev_ip6gre_fill_message_create(NetDev *netdev, Link *link, sd_netl
 }
 
 static int netdev_vti_fill_message_key(NetDev *netdev, Link *link, sd_netlink_message *m) {
-        Tunnel *t = VTI(netdev);
         uint32_t ikey, okey;
+        Tunnel *t;
         int r;
 
         assert(link);
         assert(m);
+
+        if (netdev->kind == NETDEV_KIND_VTI)
+                t = VTI(netdev);
+        else
+                t = VTI6(netdev);
+
         assert(t);
 
         if (t->key != 0)