net: Abstract default MTU metric calculation behind an accessor.
Like RTAX_ADVMSS, make the default calculation go through a dst_ops
method rather than caching the computation in the routing cache
entries.
Now dst metrics are pretty much left as-is when new entries are
created, thus optimizing metric sharing becomes a real possibility.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h
index 15fb7af..21a320b 100644
--- a/include/net/dst_ops.h
+++ b/include/net/dst_ops.h
@@ -17,6 +17,7 @@
int (*gc)(struct dst_ops *ops);
struct dst_entry * (*check)(struct dst_entry *, __u32 cookie);
unsigned int (*default_advmss)(const struct dst_entry *);
+ unsigned int (*default_mtu)(const struct dst_entry *);
void (*destroy)(struct dst_entry *);
void (*ifdown)(struct dst_entry *,
struct net_device *dev, int how);