1 files changed, 25 insertions, 0 deletions

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 519138e32fe6..7f3a5c426615 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -256,6 +256,31 @@ out:
 }
 
 /**
+ * batadv_max_header_len - calculate maximum encapsulation overhead for a
+ *  payload packet
+ *
+ * Return the maximum encapsulation overhead in bytes.
+ */
+int batadv_max_header_len(void)
+{
+        int header_len = 0;
+
+        header_len = max_t(int, header_len,
+                           sizeof(struct batadv_unicast_packet));
+        header_len = max_t(int, header_len,
+                           sizeof(struct batadv_unicast_4addr_packet));
+        header_len = max_t(int, header_len,
+                           sizeof(struct batadv_bcast_packet));
+
+#ifdef CONFIG_BATMAN_ADV_NC
+        header_len = max_t(int, header_len,
+                           sizeof(struct batadv_coded_packet));
+#endif
+
+        return header_len;
+}
+
+/**
  * batadv_skb_set_priority - sets skb priority according to packet content
  * @skb: the packet to be sent
  * @offset: offset to the packet content