sicslowpan: Fixed too aggresive fragmentation

core/net/llsec/llsec.h

@@ -85,6 +85,9 @@ struct llsec_driver {
    * filters out injected or replayed frames.
    */
   void (* input)(void);
+  
+  /** Returns the security-related overhead per frame in bytes */
+  uint8_t (* get_overhead)(void);
 };
 
 #endif /* LLSEC_H_ */

core/net/llsec/noncoresec/noncoresec.c

@@ -65,6 +65,8 @@
                          0x0C , 0x0D , 0x0E , 0x0F }
 #endif /* NONCORESEC_CONF_KEY */
 
+#define SECURITY_HEADER_LENGTH 5
+
 #define DEBUG 0
 #if DEBUG
 #include <stdio.h>
@@ -192,6 +194,12 @@ input(void)
   NETSTACK_NETWORK.input();
 }
 /*---------------------------------------------------------------------------*/
+static uint8_t
+get_overhead(void)
+{
+  return SECURITY_HEADER_LENGTH + LLSEC802154_MIC_LENGTH;
+}
+/*---------------------------------------------------------------------------*/
 static void
 bootstrap(llsec_on_bootstrapped_t on_bootstrapped)
 {
@@ -205,7 +213,8 @@ const struct llsec_driver noncoresec_driver = {
   bootstrap,
   send,
   on_frame_created,
-  input
+  input,
+  get_overhead
 };
 /*---------------------------------------------------------------------------*/
 

core/net/llsec/nullsec.c

@@ -73,12 +73,19 @@ input(void)
   NETSTACK_NETWORK.input();
 }
 /*---------------------------------------------------------------------------*/
+static uint8_t
+get_overhead(void)
+{
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
 const struct llsec_driver nullsec_driver = {
   "nullsec",
   bootstrap,
   send,
   on_frame_created,
-  input
+  input,
+  get_overhead
 };
 /*---------------------------------------------------------------------------*/