Fix issue 59. Drop a fragment that extends past the maximum IP packet size.

src/defrag.c

@@ -14,6 +14,7 @@
  * \todo pool for frag packet storage
  * \todo policy bsd-right
  * \todo profile hash function
+ * \todo log anomalies
  */
 
 #include <sys/time.h>
@@ -531,6 +532,11 @@ DefragInsertFrag(DefragContext *dc, DefragTracker *tracker, Packet *p)
         exit(EXIT_FAILURE);
     }
 
+    if (frag_offset + data_len > IPV4_MAXPACKET_LEN) {
+        /* \todo Log this - packet is too large to be re-assembled. */
+        return;
+    }
+
     /* Lock this tracker as we'll be doing list operations on it. */
     SCMutexLock(&tracker->lock);