net: nrf_provisioning: Simplify scheluding calculations

The nrf_provisioning_schedule() had too many if-else things.
Simplyfy the calculations a bit.

* If date_time_now() fails, just retry until we get a proper time.
* Rescheduling is just now+interval
* Initialize the srand() by kernel timer.

Fix testcases to use correct clock always.

Signed-off-by: Seppo Takalo <[email protected]>

Author: SeppoTakalo

subsys/net/lib/nrf_provisioning/src/nrf_provisioning.c

@@ -491,6 +491,8 @@ int nrf_provisioning_schedule(void)
 						: CONFIG_NRF_PROVISIONING_INTERVAL_S;
 		LOG_DBG("First provisioning, setting interval to %lld seconds",
 			(int64_t)provisioning_interval);
+		/* Delay spread does not need high-entropy randomness */
+		srand(k_uptime_get_32());
 		goto out;
 	}
 
@@ -501,47 +503,34 @@ int nrf_provisioning_schedule(void)
 			LOG_ERR("Getting time failed, error: %d", ret);
 		}
 
-		if (provisioning_interval) {
-			retry_s = provisioning_interval;
-		} else {
-			/* Backoff... */
-			retry_s = retry_s * 2;
+		/* Backoff... */
+		retry_s = retry_s * 2;
 
-			/* ...up to a degree */
-			if (retry_s > CONFIG_NRF_PROVISIONING_INTERVAL_S) {
-				retry_s = CONFIG_NRF_PROVISIONING_INTERVAL_S;
-			}
+		/* ...up to a degree */
+		if (retry_s > CONFIG_NRF_PROVISIONING_INTERVAL_S) {
+			retry_s = CONFIG_NRF_PROVISIONING_INTERVAL_S;
 		}
 
 		goto out;
 	}
 
 	now_s /= 1000; /* date_time_now() is ms */
-	if (now_s > deadline_s || reschedule) {
-
-		/* Provision now */
-		if (!provisioning_interval && !deadline_s) {
-			deadline_s = now_s + CONFIG_NRF_PROVISIONING_INTERVAL_S;
-			retry_s = 0;
-			goto out;
-		}
 
+	if (now_s > deadline_s || reschedule) {
 		/* Interval set by the server takes precedence */
-		deadline_s = provisioning_interval ? now_s + provisioning_interval :
-			now_s + CONFIG_NRF_PROVISIONING_INTERVAL_S;
+		deadline_s = now_s + (provisioning_interval ? provisioning_interval
+							    : CONFIG_NRF_PROVISIONING_INTERVAL_S);
 	}
 
 	retry_s = deadline_s - now_s;
 out:
-	/* Delay spread does not need high-entropy randomness */
-	srand(now_s);
 	spread_s = rand() %
 		(CONFIG_NRF_PROVISIONING_SPREAD_S ? CONFIG_NRF_PROVISIONING_SPREAD_S : 1);
 
 	/* To even the load on server side */
 	retry_s += spread_s;
 
-	LOG_INF("Checking for provisioning commands in %lld seconds", retry_s);
+	LOG_INF("Checking for provisioning commands in %lld seconds", (int64_t) retry_s);
 	reschedule = false;
 
 	return retry_s;

tests/subsys/net/lib/nrf_provisioning/src/coap.c

@@ -183,10 +183,17 @@ struct coap_transmission_parameters coap_get_transmission_parameters(void)
 	return coap_transmission_params;
 }
 
+static int time_now(int64_t *unix_time_ms, int cmock_num_calls)
+{
+	*unix_time_ms = (int64_t)time(NULL) * MSEC_PER_SEC;
+	return 0;
+}
+
 void setUp(void)
 {
 	k_sem_reset(&stopped_sem);
 	k_sem_reset(&done_sem);
+	__cmock_date_time_now_Stub(time_now);
 }
 
 void tearDown(void)
@@ -753,7 +760,6 @@ void test_provisioning_init_change_cbs_valid(void)
 	__cmock_lte_lc_connect_Stub(lte_lc_connect_cb);
 	/* No way to check that the correct handler is passed as an argument */
 	__cmock_lte_lc_register_handler_Ignore();
-	__cmock_date_time_now_IgnoreAndReturn(0);
 
 	/* To make certain init has been called at least once beforehand */
 	int ret = nrf_provisioning_init(NULL, NULL);
@@ -794,7 +800,6 @@ void test_provisioning_task_valid(void)
 	__cmock_lte_lc_func_mode_get_IgnoreAndReturn(0);
 	__cmock_nrf_provisioning_at_cmee_enable_IgnoreAndReturn(0);
 	__cmock_nrf_provisioning_at_cmee_control_IgnoreAndReturn(0);
-	__cmock_date_time_now_IgnoreAndReturn(0);
 
 	__cmock_modem_info_get_fw_version_ExpectAnyArgsAndReturn(0);
 	__cmock_modem_info_get_fw_version_ReturnArrayThruPtr_buf(MFW_VER, sizeof(MFW_VER));
@@ -844,7 +849,6 @@ void test_provisioning_commands(void)
 	__cmock_lte_lc_func_mode_get_IgnoreAndReturn(0);
 	__cmock_nrf_provisioning_at_cmee_enable_IgnoreAndReturn(0);
 	__cmock_nrf_provisioning_at_cmee_control_IgnoreAndReturn(0);
-	__cmock_date_time_now_IgnoreAndReturn(0);
 	__cmock_settings_load_subtree_IgnoreAndReturn(0);
 
 	/* To make certain init has been called at least once beforehand */
@@ -1013,13 +1017,6 @@ void test_coap_rsp_unsupported_code(void)
 	TEST_ASSERT_EQUAL_INT(-ENOTSUP, ret);
 }
 
-static int time_now(int64_t *unix_time_ms, int cmock_num_calls)
-{
-	*unix_time_ms = (int64_t)time(NULL);
-
-	return 0;
-}
-
 /*
  * - Get when next provisioning should be executed
  * - The client should follow the interval configured
@@ -1031,14 +1028,8 @@ void test_provisioning_schedule_valid(void)
 	/* To avoid being entangled to other tests let's assume that the function has
 	 * never been called earlier. If that's not the case let's just ignore the first invocation.
 	 */
-	__cmock_date_time_now_IgnoreAndReturn(0);
 	(void)nrf_provisioning_schedule();
 
-	__cmock_date_time_now_StopIgnore();
-
-	__cmock_date_time_now_AddCallback(time_now);
-	__cmock_date_time_now_ExpectAnyArgsAndReturn(0);
-
 	int ret = nrf_provisioning_schedule();
 
 	/* Can't have exact match due to the spread factor */
@@ -1059,12 +1050,8 @@ void test_provisioning_schedule_no_nw_time_valid(void)
 	/* To avoid being entangled to other tests let's assume that the function has
 	 * never been called earlier. If that's not the case let's just ignore the first invocation.
 	 */
-	__cmock_date_time_now_AddCallback(time_now);
-	__cmock_date_time_now_IgnoreAndReturn(0);
 	(void)nrf_provisioning_schedule();
 
-	__cmock_date_time_now_StopIgnore();
-
 	__cmock_date_time_now_ExpectAnyArgsAndReturn(-1);
 
 	int ret = nrf_provisioning_schedule();