nimble/ll/test: Refactor ISO tests and implement test fixtures

This refactors the ISO test suite by introducing a dedicated test
fixture, which ensures a clean state for every individual test case.
By automating the reset process, we reduce boilerplate code and make
the suite significantly easier to maintain and extend.

Additionally, the ISO test buffer size has been re-evaluated and
adjusted to properly accommodate both the payload data and the
required ISO headers, preventing potential buffer overflows during
testing.

Author: MariuszSkamra

nimble/controller/test/src/ble_ll_iso.c

@@ -80,6 +80,41 @@ const struct test_ll_common_params test_ll_common_params_bn_1 = {
     .Sync_Timeout = 100,
 };
 
+struct test_ll_iso_fixture {
+    struct ble_ll_iso_conn conn;
+};
+
+static void
+test_ll_iso_setup(struct test_ll_iso_fixture *fixture,
+                  const struct test_ll_common_params *params)
+{
+    struct ble_ll_iso_conn_init_param conn_param = {
+        .iso_interval_us = params->SDU_Interval * 1000,
+        .sdu_interval_us = params->SDU_Interval * 1000,
+        .conn_handle = 0x0001,
+        .max_sdu = TSPX_max_tx_payload,
+        .max_pdu = TSPX_max_tx_payload,
+        .framing = params->Framing,
+        .bn = params->BN
+    };
+    struct ble_ll_iso_conn *conn;
+
+    memset(fixture, 0, sizeof(*fixture));
+    conn = &fixture->conn;
+
+    ble_ll_iso_conn_init(conn, &conn_param);
+}
+
+static void
+test_ll_iso_teardown(struct test_ll_iso_fixture *fixture)
+{
+    struct ble_ll_iso_conn *conn;
+
+    conn = &fixture->conn;
+
+    ble_ll_iso_conn_free(conn);
+}
+
 TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
     const uint8_t payload_types[] = {
         BLE_HCI_PAYLOAD_TYPE_ZERO_LENGTH,
@@ -93,23 +128,17 @@ TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
     struct ble_hci_le_iso_transmit_test_rp iso_transmit_test_rp;
     struct ble_hci_le_iso_test_end_cp iso_test_end_cp;
     struct ble_hci_le_iso_test_end_rp iso_test_end_rp;
-    struct ble_ll_iso_conn_init_param conn_param = {
-        .iso_interval_us = params->SDU_Interval * 1000,
-        .sdu_interval_us = params->SDU_Interval * 1000,
-        .conn_handle = 0x0001,
-        .max_sdu = TSPX_max_tx_payload,
-        .max_pdu = TSPX_max_tx_payload,
-        .framing = params->Framing,
-        .bn = params->BN
-    };
-    struct ble_ll_iso_conn conn;
+    struct test_ll_iso_fixture fixture;
+    struct ble_ll_iso_conn *conn;
     uint8_t payload_type;
     uint8_t pdu[100];
     uint8_t llid;
     uint8_t rsplen = 0;
     int rc;
 
-    ble_ll_iso_conn_init(&conn, &conn_param);
+    test_ll_iso_setup(&fixture, params);
+
+    conn = &fixture.conn;
 
     for (uint8_t i = 0; i < ARRAY_SIZE(payload_types); i++) {
         payload_type = payload_types[i];
@@ -118,7 +147,7 @@ TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
          *    specified in Table 4.12-2 and receives a successful HCI_Command_Complete event from the IUT in response.
          */
         rsplen = 0xFF;
-        iso_transmit_test_cp.conn_handle = htole16(conn.handle);
+        iso_transmit_test_cp.conn_handle = htole16(conn->handle);
         iso_transmit_test_cp.payload_type = payload_type;
         rc = ble_ll_iso_transmit_test((uint8_t *)&iso_transmit_test_cp, sizeof(iso_transmit_test_cp),
                                       (uint8_t *)&iso_transmit_test_rp, &rsplen);
@@ -131,32 +160,32 @@ TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
          * 4. Repeat step 3 for a total of 5 payloads.
          */
         for (uint8_t j = 0; j < 5; j++) {
-            rc = ble_ll_iso_conn_event_start(&conn, 30000);
+            rc = ble_ll_iso_conn_event_start(conn, 30000);
             TEST_ASSERT(rc == 0);
 
-            for (uint8_t k = 0; k < conn_param.bn; k++) {
+            for (uint8_t k = 0; k < conn->mux.bn; k++) {
                 llid = 0xFF;
-                rc = ble_ll_iso_pdu_get(&conn, k, k, &llid, pdu);
+                rc = ble_ll_iso_pdu_get(conn, k, k, &llid, pdu);
                 if (payload_type == BLE_HCI_PAYLOAD_TYPE_ZERO_LENGTH) {
                     TEST_ASSERT(rc == 0);
                     TEST_ASSERT(llid == 0b00);
                 } else if (payload_type == BLE_HCI_PAYLOAD_TYPE_VARIABLE_LENGTH) {
                     TEST_ASSERT(rc >= 4);
                     TEST_ASSERT(llid == 0b00);
                 } else if (payload_type == BLE_HCI_PAYLOAD_TYPE_MAXIMUM_LENGTH) {
-                    TEST_ASSERT(rc == conn_param.max_pdu);
+                    TEST_ASSERT(rc == conn->mux.max_pdu);
                     TEST_ASSERT(llid == 0b00);
                 }
             }
 
-            rc = ble_ll_iso_conn_event_done(&conn);
+            rc = ble_ll_iso_conn_event_done(conn);
             TEST_ASSERT(rc == 0);
         }
 
         /* 5. The Upper Tester sends an HCI_LE_Setup_ISO_Data_Path command to the IUT.
          * 6. The IUT sends an HCI_Command_Complete event to the Upper Tester with Status set to 0x0C.
          */
-        setup_iso_data_path_cp.conn_handle = htole16(conn.handle);
+        setup_iso_data_path_cp.conn_handle = htole16(conn->handle);
         setup_iso_data_path_cp.data_path_dir = 0x00;
         setup_iso_data_path_cp.data_path_id = 0x00;
         rc = ble_ll_iso_setup_iso_data_path((uint8_t *)&setup_iso_data_path_cp, sizeof(setup_iso_data_path_cp),
@@ -168,7 +197,7 @@ TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
          *    Received_SDU_Count, Missed_SDU_Count, and Failed_SDU_Count are all zero.
          */
         rsplen = 0xFF;
-        iso_test_end_cp.conn_handle = htole16(conn.handle);
+        iso_test_end_cp.conn_handle = htole16(conn->handle);
         rc = ble_ll_iso_end_test((uint8_t *)&iso_test_end_cp, sizeof(iso_test_end_cp),
                                  (uint8_t *)&iso_test_end_rp, &rsplen);
         TEST_ASSERT(rc == 0);
@@ -179,7 +208,7 @@ TEST_CASE_SELF(test_ll_ist_brd_bv_01_c) {
         TEST_ASSERT(iso_test_end_rp.failed_sdu_count == 0);
     }
 
-    ble_ll_iso_conn_free(&conn);
+    test_ll_iso_teardown(&fixture);
 }
 
 TEST_SUITE(ble_ll_iso_test_suite) {