1 files changed, 23 insertions, 0 deletions

diff --git a/net/batman-adv/unicast.h b/net/batman-adv/unicast.h
index e32b7867a9a4..e7211c279201 100644
--- a/net/batman-adv/unicast.h
+++ b/net/batman-adv/unicast.h
@@ -22,6 +22,8 @@
 #ifndef _NET_BATMAN_ADV_UNICAST_H_
 #define _NET_BATMAN_ADV_UNICAST_H_
 
+#include "packet.h"
+
 #define FRAG_TIMEOUT 10000      /* purge frag list entrys after time in ms */
 #define FRAG_BUFFER_SIZE 6      /* number of list elements in buffer */
 
@@ -32,4 +34,25 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv);
 int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
                   struct batman_if *batman_if, uint8_t dstaddr[]);
 
+static inline int frag_can_reassemble(struct sk_buff *skb, int mtu)
+{
+        struct unicast_frag_packet *unicast_packet;
+        int uneven_correction = 0;
+        unsigned int merged_size;
+
+        unicast_packet = (struct unicast_frag_packet *)skb->data;
+
+        if (unicast_packet->flags & UNI_FRAG_LARGETAIL) {
+                if (unicast_packet->flags & UNI_FRAG_HEAD)
+                        uneven_correction = 1;
+                else
+                        uneven_correction = -1;
+        }
+
+        merged_size = (skb->len - sizeof(struct unicast_frag_packet)) * 2;
+        merged_size += sizeof(struct unicast_packet) + uneven_correction;
+
+        return merged_size <= mtu;
+}
+
 #endif /* _NET_BATMAN_ADV_UNICAST_H_ */