Adaptation IF: Allocate fragmentation buffer only if needed (ARMmbed#2407)

* Adaptation IF: Allocate fragmentation buffer only if needed

* unit tests: fixed adaptation interface tests

Author: Jarkko Paso

source/6LoWPAN/adaptation_interface.c

@@ -351,17 +351,14 @@ int8_t lowpan_adaptation_interface_init(int8_t interface_id, uint16_t mac_mtu_si
 
     //Allocate new
     fragmenter_interface_t *interface_ptr = ns_dyn_mem_alloc(sizeof(fragmenter_interface_t));
-    uint8_t *tx_buffer = ns_dyn_mem_alloc(mac_mtu_size);
-    if (!interface_ptr  || !tx_buffer) {
-        ns_dyn_mem_free(interface_ptr);
-        ns_dyn_mem_free(tx_buffer);
+    if (!interface_ptr) {
         return -1;
     }
 
     memset(interface_ptr, 0, sizeof(fragmenter_interface_t));
     interface_ptr->interface_id = interface_id;
-    interface_ptr->fragment_indirect_tx_buffer = tx_buffer;
-    interface_ptr->mtu_size = mac_mtu_size;
+    interface_ptr->fragment_indirect_tx_buffer = NULL;
+    interface_ptr->mtu_size = 0;
     interface_ptr->msduHandle = randLIB_get_8bit();
     interface_ptr->local_frag_tag = randLIB_get_16bit();
 
@@ -997,6 +994,18 @@ int8_t lowpan_adaptation_interface_tx(protocol_interface_info_entry_t *cur, buff
 
     //Check packet size
     bool fragmented_needed = lowpan_adaptation_request_longer_than_mtu(cur, buf, interface_ptr);
+    if (fragmented_needed) {
+        // If fragmentation TX buffer not allocated, do it now.
+        if (!interface_ptr->fragment_indirect_tx_buffer && !interface_ptr->mtu_size) {
+            interface_ptr->fragment_indirect_tx_buffer = ns_dyn_mem_alloc(cur->mac_api->phyMTU);
+            if (interface_ptr->fragment_indirect_tx_buffer) {
+                interface_ptr->mtu_size = cur->mac_api->phyMTU;
+            } else {
+                tr_error("Failed to allocate fragmentation buffer");
+                goto tx_error_handler;
+            }
+        }
+    }
     bool is_unicast = buf->link_specific.ieee802_15_4.requestAck;
     bool indirect = buf->link_specific.ieee802_15_4.indirectTxProcess;
 

source/MAC/IEEE802_15_4/sw_mac.c

@@ -104,9 +104,9 @@ mac_api_t *ns_sw_mac_create(int8_t rf_driver_id, mac_description_storage_size_t
 
     // Set default MTU size to 127 unless it is too much for PHY driver
     if (driver->phy_driver->phy_MTU > MAC_IEEE_802_15_4_MAX_PHY_PACKET_SIZE) {
-        this->phyMTU = driver->phy_driver->phy_MTU;
-    } else {
         this->phyMTU = MAC_IEEE_802_15_4_MAX_PHY_PACKET_SIZE;
+    } else {
+        this->phyMTU = driver->phy_driver->phy_MTU;
     }
 
     mac_store.setup = mac_mlme_data_base_allocate(mac_store.dev_driver->phy_driver->PHY_MAC, mac_store.dev_driver, storage_sizes, this->phyMTU);

test/nanostack/unittest/6LoWPAN/adaptation_interface/test_adaptation_interface.c

@@ -65,26 +65,17 @@ bool test_lowpan_adaptation_interface_init()
         return false;
     }
 
-    if (-1 != lowpan_adaptation_interface_init(0, 127)) {
-        return false;
-    }
-
     nsdynmemlib_stub.returnCounter = 0;
-
-    if (-1 != lowpan_adaptation_interface_init(0, 127)) {
-        return false;
-    }
-    nsdynmemlib_stub.returnCounter = 1;
     if (-1 != lowpan_adaptation_interface_init(0, 127)) {
         return false;
     }
 
-    nsdynmemlib_stub.returnCounter = 2;
+    nsdynmemlib_stub.returnCounter = 1;
     if (0 != lowpan_adaptation_interface_init(0, 127)) {
         return false;
     }
 
-    nsdynmemlib_stub.returnCounter = 2;
+    nsdynmemlib_stub.returnCounter = 1;
     if (0 != lowpan_adaptation_interface_init(0, 127)) {
         return false;
     }
@@ -387,6 +378,7 @@ bool test_lowpan_adaptation_interface_tx()
     entry.id = 0;
     api.mcps_data_req = &mcps_data_req_cb;
     api.mcps_purge_req = &tester_mcps_purge_request;
+    api.phyMTU = 127;
     mac_neighbor_table_stub.test_neigh = NULL;
 
     buffer_t *test_buf = malloc(sizeof(buffer_t) + 2100);
@@ -428,7 +420,7 @@ bool test_lowpan_adaptation_interface_tx()
     }
 
     //Test Indirect data allocation fail
-    nsdynmemlib_stub.returnCounter = 2;
+    nsdynmemlib_stub.returnCounter = 1;
     lowpan_adaptation_interface_init(0, 127);
 
     if (0 != lowpan_adaptation_indirect_queue_params_set(&entry, 106, 1, 2)) {
@@ -774,6 +766,7 @@ bool test_lowpan_adaptation_interface_tx_confirm()
     entry.mac_api = &api;
     entry.id = 0;
     api.mcps_data_req = &mcps_data_req_cb;
+    api.phyMTU = 127;
     mac_neighbor_table_stub.test_neigh = NULL;
 
     mac_helper_stub.uint16_value = 110;