Test API to adjust 6LoWPAN fragmentation MTU size (ARMmbed#2398)

Add test API to allow testing of 6LoWPAN fragmentation.

Author: Arto Kinnunen

nanostack/net_ws_test.h

@@ -167,6 +167,17 @@ int ws_test_gtk_time_settings_set(
  */
 int ws_test_next_gtk_set(int8_t interface_id, uint8_t *gtk[4]);
 
+/**
+ * Sets 6LoWPAN fragmentation MTU size to test fragmentation
+ *
+ * \param interface_id Network interface ID.
+ * \param mtu_size Size of 6LoWPAN MTU when fragmentation occurs.
+ *
+ * \return 0                        Success
+ * \return <0                       Failure
+ */
+int ws_test_6lowpan_fragmentation_mtu_size_set(int8_t interface_id, uint16_t mtu_size);
+
 #ifdef __cplusplus
 }
 #endif

source/6LoWPAN/MAC/mac_helper.c

@@ -31,6 +31,8 @@
 
 static const uint8_t mac_helper_default_key_source[8] = {0xff, 0, 0, 0, 0, 0, 0, 0};
 
+uint16_t test_6lowpan_fragmentation_mtu_size_override = 0;
+
 static uint8_t mac_helper_header_security_aux_header_length(uint8_t keyIdmode);
 static uint8_t mac_helper_security_mic_length_get(uint8_t security_level);
 static void mac_helper_keytable_pairwise_descriptor_set(struct mac_api_s *api, const uint8_t *key, const uint8_t *mac64, uint8_t attribute_id);
@@ -736,14 +738,19 @@ uint_fast16_t mac_helper_max_payload_size(protocol_interface_info_entry_t *cur,
 {
     uint16_t max;
 
-    max = cur->mac_api->phyMTU - frame_overhead;
+    if (test_6lowpan_fragmentation_mtu_size_override == 0) {
+        max = cur->mac_api->phyMTU - frame_overhead;
+    } else {
+        max = test_6lowpan_fragmentation_mtu_size_override - frame_overhead;
+    }
 
     /* But if we want IEEE 802.15.4-2003 compatibility (and it looks like a
      * standard PHY), limit ourselves to the 2003 maximum */
     if (cur->mac_parameters->MacUnsusecured_2003_cab && max > MAC_IEEE_802_15_4_MAX_MAC_SAFE_PAYLOAD_SIZE &&
             cur->mac_api->phyMTU == MAC_IEEE_802_15_4_MAX_PHY_PACKET_SIZE) {
         max = MAC_IEEE_802_15_4_MAX_MAC_SAFE_PAYLOAD_SIZE;
     }
+
     return max;
 }
 

source/6LoWPAN/MAC/mac_helper.h

@@ -30,6 +30,7 @@ struct ns_sockaddr;
 struct buffer;
 struct mac_api_s;
 
+extern uint16_t test_6lowpan_fragmentation_mtu_size_override;
 
 void mac_create_scan_request(mac_scan_type_t type, struct channel_list_s *chanlist, uint8_t scan_duration, struct mlme_scan_s *request);
 

source/6LoWPAN/ws/ws_test_api.c

@@ -18,12 +18,13 @@
 #include "nsconfig.h"
 
 #include <string.h>
-#include <ns_list.h>
-#include <nsdynmemLIB.h>
-#include <net_ws_test.h>
+#include "ns_list.h"
+#include "nsdynmemLIB.h"
+#include "net_ws_test.h"
 #include "fhss_config.h"
 #include "ws_management_api.h"
 #include "mac_api.h"
+#include "6LoWPAN/MAC/mac_helper.h"
 #include "NWK_INTERFACE/Include/protocol.h"
 #include "6LoWPAN/MAC/mac_helper.h"
 #include "6LoWPAN/ws/ws_config.h"
@@ -150,4 +151,17 @@ int ws_test_next_gtk_set(int8_t interface_id, uint8_t *gtk[4])
     return ws_pae_controller_next_gtk_update(interface_id, gtk);
 }
 
+int ws_test_6lowpan_fragmentation_mtu_size_set(int8_t interface_id, uint16_t mtu_size)
+{
+    protocol_interface_info_entry_t *cur;
+
+    cur = protocol_stack_interface_info_get_by_id(interface_id);
+    if (!cur || !ws_info(cur)) {
+        return -1;
+    }
+
+    test_6lowpan_fragmentation_mtu_size_override = mtu_size;
+    return 0;
+}
+
 #endif // HAVE_WS