1 files changed, 13 insertions, 0 deletions

diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 78892e2f53e3..278ff7f616f9 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -39,6 +39,7 @@
 
 #include "netlink.h"
 #include "core.h"
+#include "msg.h"
 #include <net/genetlink.h>
 
 #define MAX_MEDIA       3
@@ -59,6 +60,9 @@
 #define TIPC_MEDIA_TYPE_IB      2
 #define TIPC_MEDIA_TYPE_UDP     3
 
+/* minimum bearer MTU */
+#define TIPC_MIN_BEARER_MTU     (MAX_H_SIZE + INT_H_SIZE)
+
 /**
  * struct tipc_media_addr - destination address used by TIPC bearers
  * @value: address info (format defined by media)
@@ -215,4 +219,13 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
                          struct sk_buff_head *xmitq);
 
+/* check if device MTU is too low for tipc headers */
+static inline bool tipc_mtu_bad(struct net_device *dev, unsigned int reserve)
+{
+        if (dev->mtu >= TIPC_MIN_BEARER_MTU + reserve)
+                return false;
+        netdev_warn(dev, "MTU too low for tipc bearer\n");
+        return true;
+}
+
 #endif  /* _TIPC_BEARER_H */