FHSS WS: Allow transmitting unicast frames on broadcast channel for 1st hop node in EF mode (ARMmbed#2609)

* FHSS WS: Allow unicast on broadcast channel for 1st hop in EF mode

* Unit tests for FHSS EF mode updated

Author: Jarkko Paso

source/Service_Libs/fhss/fhss_ws.c

@@ -85,6 +85,7 @@ static void fhss_unicast_handler(const fhss_api_t *fhss_api, uint16_t delay);
 static void fhss_broadcast_handler(const fhss_api_t *fhss_api, uint16_t delay);
 static bool fhss_ws_check_tx_allowed(fhss_structure_t *fhss_structure);
 static bool fhss_allow_transmitting_on_rx_slot(fhss_structure_t *fhss_structure);
+static bool fhss_allow_unicast_on_broadcast_channel(fhss_structure_t *fhss_structure);
 static int32_t fhss_channel_index_from_mask(const uint32_t *channel_mask, int32_t channel_index, uint16_t number_of_channels);
 
 // This function supports rounding up
@@ -654,8 +655,11 @@ static int fhss_ws_tx_handle_callback(const fhss_api_t *api, bool is_broadcast_a
     if (is_broadcast_addr && (fhss_structure->ws->is_on_bc_channel == false)) {
         return -3;
     }
-    // Do not allow unicast destination on broadcast channel
+    // Do not allow unicast destination on broadcast channel unless it is specifically enabled
     if (!is_broadcast_addr && (fhss_structure->ws->is_on_bc_channel == true)) {
+        if (fhss_allow_unicast_on_broadcast_channel(fhss_structure)) {
+            return 0;
+        }
         return -3;
     }
     // Check TX/RX slot
@@ -786,6 +790,18 @@ static bool fhss_allow_transmitting_on_rx_slot(fhss_structure_t *fhss_structure)
     return true;
 }
 
+static bool fhss_allow_unicast_on_broadcast_channel(fhss_structure_t *fhss_structure)
+{
+    // This is allowed only for 1st hop devices in expedited forwarding mode
+    if (!fhss_structure->ws->expedited_forwarding_enabled_us) {
+        return false;
+    }
+    if (fhss_structure->own_hop != 1) {
+        return false;
+    }
+    return true;
+}
+
 static bool fhss_ws_check_tx_conditions_callback(const fhss_api_t *api, bool is_broadcast_addr, uint8_t handle, int frame_type, uint16_t frame_length, uint8_t phy_header_length, uint8_t phy_tail_length)
 {
     (void) frame_type;
@@ -797,8 +813,8 @@ static bool fhss_ws_check_tx_conditions_callback(const fhss_api_t *api, bool is_
     if (is_broadcast_addr && (fhss_structure->ws->is_on_bc_channel == false)) {
         return false;
     }
-    // Do not allow unicast destination on broadcast channel
-    if (!is_broadcast_addr && (fhss_structure->ws->is_on_bc_channel == true)) {
+    // Do not allow unicast destination on broadcast channel unless it is specifically enabled
+    if (!is_broadcast_addr && (fhss_structure->ws->is_on_bc_channel == true) && !fhss_allow_unicast_on_broadcast_channel(fhss_structure)) {
         return false;
     }
     // This condition will check that message is not sent on bad channel

test/nanostack/unittest/service_libs/fhss_ws/test_fhss_ws.c

@@ -376,6 +376,34 @@ bool test_fhss_ws_tx_handle_callback()
         printf("Fail: TX handle, 1st hop, EF disabled on TX slot\r\n");
         return false;
     }
+    // Test TX allowed on broadcast channel for 1st hop in expedited forwarding mode
+    fhss_common_stub.fhss_struct.ws->is_on_bc_channel = true;
+    fhss_common_stub.fhss_struct.own_hop = 1;
+    fhss_common_stub.fhss_struct.ws->expedited_forwarding_enabled_us = 1000000;
+    fhss_common_stub.fhss_struct.ws->fhss_configuration.fhss_broadcast_interval = 1020;
+    fhss_common_stub.fhss_struct.ws->fhss_configuration.fhss_bc_dwell_interval = 255;
+    fhss_common_stub.fhss_struct.ws->txrx_slot_length_ms = 54;
+    fhss_platform_stub.remaining_slots_value = 750000;
+    if (fhss_common_stub.fhss_struct.fhss_api->tx_handle(api, DEFAULT_IS_BC_DEST, dest_address, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH, DEFAULT_TX_TIME) != 0) {
+        printf("Fail: TX handle, 1st hop, EF enabled on BC\r\n");
+        return false;
+    }
+    // Test TX not allowed on broadcast channel for 2nd hop in expedited forwarding mode
+    fhss_common_stub.fhss_struct.ws->is_on_bc_channel = true;
+    fhss_common_stub.fhss_struct.own_hop = 2;
+    fhss_common_stub.fhss_struct.ws->expedited_forwarding_enabled_us = 1000000;
+    if (fhss_common_stub.fhss_struct.fhss_api->tx_handle(api, DEFAULT_IS_BC_DEST, dest_address, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH, DEFAULT_TX_TIME) != -3) {
+        printf("Fail: TX handle, 2nd hop, EF enabled on BC\r\n");
+        return false;
+    }
+    // Test TX not allowed on broadcast channel for 1st hop when expedited forwarding mode disabled
+    fhss_common_stub.fhss_struct.ws->is_on_bc_channel = true;
+    fhss_common_stub.fhss_struct.own_hop = 1;
+    fhss_common_stub.fhss_struct.ws->expedited_forwarding_enabled_us = 0;
+    if (fhss_common_stub.fhss_struct.fhss_api->tx_handle(api, DEFAULT_IS_BC_DEST, dest_address, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH, DEFAULT_TX_TIME) != -3) {
+        printf("Fail: TX handle, 1st hop, EF disabled on BC\r\n");
+        return false;
+    }
 
     return true;
 }
@@ -496,6 +524,31 @@ bool test_fhss_ws_check_tx_conditions_callback()
         printf("Fail: TX conditions, 3rd hop, EF enabled on RX slot\r\n");
         return false;
     }
+    // Test TX allowed on broadcast channel for 1st hop in expedited forwarding mode
+    fhss_common_stub.fhss_struct.own_hop = 1;
+    fhss_common_stub.fhss_struct.ws->is_on_bc_channel = true;
+    fhss_common_stub.fhss_struct.ws->expedited_forwarding_enabled_us = 1000000;
+    fhss_common_stub.fhss_struct.ws->fhss_configuration.fhss_broadcast_interval = 1020;
+    fhss_common_stub.fhss_struct.ws->fhss_configuration.fhss_bc_dwell_interval = 255;
+    fhss_common_stub.fhss_struct.ws->txrx_slot_length_ms = 54;
+    fhss_platform_stub.remaining_slots_value = 750000;
+    if (fhss_common_stub.fhss_struct.fhss_api->check_tx_conditions(api, DEFAULT_IS_BC_DEST, DEFAULT_HANDLE, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH) != true) {
+        printf("Fail: TX conditions, 1st hop, EF enabled on BC\r\n");
+        return false;
+    }
+    // Test TX not allowed on broadcast channel for 2nd hop in expedited forwarding mode
+    fhss_common_stub.fhss_struct.own_hop = 2;
+    if (fhss_common_stub.fhss_struct.fhss_api->check_tx_conditions(api, DEFAULT_IS_BC_DEST, DEFAULT_HANDLE, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH) != false) {
+        printf("Fail: TX conditions, 2nd hop, EF enabled on BC\r\n");
+        return false;
+    }
+    // Test TX not allowed on broadcast channel for 1st hop when expedited forwarding mode disabled
+    fhss_common_stub.fhss_struct.own_hop = 1;
+    fhss_common_stub.fhss_struct.ws->expedited_forwarding_enabled_us = 0;
+    if (fhss_common_stub.fhss_struct.fhss_api->check_tx_conditions(api, DEFAULT_IS_BC_DEST, DEFAULT_HANDLE, DEFAULT_FRAME_TYPE, DEFAULT_FRAME_LENGTH, DEFAULT_PHY_HEAD_LENGTH, DEFAULT_PHY_TAIL_LENGTH) != false) {
+        printf("Fail: TX conditions, 1st hop, EF disabled on BC\r\n");
+        return false;
+    }
 
     return true;
 }