[nrf fromtree] test: bluetooth: tester: Fix GAP/CONN/DCON/BV-05-C test

For GAP/CONN/DCON/BV-05-C PTS expects IUT to fail operation
if the peer does not support Central Address Resolution.

In Test Set there is ALT to start undirected advertising instead
but PTS interpretation is that IUT shall reject directed request
regardless and may then later on follow up with underected
advertising (which PTS doesn't validate). To keep this simple
just reject here.

Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>
(cherry picked from commit 2f5145b)
Signed-off-by: Alperen Sener <alperen.sener@nordicsemi.no>

Author: sjanc

tests/bluetooth/tester/src/btp_gap.c

@@ -992,8 +992,8 @@ static uint8_t start_advertising(const void *cmd, uint16_t cmd_len,
 
 /**
  * Start directed advertising with a peer address with or without RPA.
- * If privacy is enabled and the peer does not support Central Address Resolution,
- * the advertisement will be started as undirected with RPA.
+ * If privacy is enabled and the peer does not support Central Address
+ * Resolution PTS expects IUT request to fail.
  */
 static uint8_t start_directed_advertising(const void *cmd, uint16_t cmd_len,
 					  void *rsp, uint16_t *rsp_len)
@@ -1003,36 +1003,50 @@ static uint8_t start_directed_advertising(const void *cmd, uint16_t cmd_len,
 	struct bt_le_adv_param adv_param = BT_LE_ADV_PARAM_INIT(
 		BT_LE_ADV_OPT_CONN, BT_GAP_ADV_FAST_INT_MIN_2, BT_GAP_ADV_FAST_INT_MAX_2, NULL);
 	uint16_t options = sys_le16_to_cpu(cp->options);
+	bool peer_car_supported = false;
 
 	if (bt_addr_le_eq(&cp->address, &bt_addr_le_any)) {
 		LOG_ERR("Invalid peer address");
 		return BTP_STATUS_FAILED;
 	}
 
-	if (IS_ENABLED(CONFIG_BT_PRIVACY) && (options & BTP_GAP_START_DIRECTED_ADV_PEER_RPA)) {
-		/**
-		 * In accordance with the test spec for test case GAP/CONN/DCON/BV-05-C, if the peer
-		 * does not support Central Address Resolution, the advertisement will be started
-		 * as undirected.
-		 */
+	/*
+	 * For GAP/CONN/DCON/BV-05-C PTS expects IUT to fail operation
+	 * if the peer does not support Central Address Resolution.
+	 *
+	 * In Test Set there is ALT to start undirected advertising instead
+	 * but PTS interpretation is that IUT shall reject directed request
+	 * regardless and may then later on follow up with underected
+	 * advertising (which PTS doesn't validate). To keep this simple
+	 * just reject here.
+	 */
+	if ((options & BTP_GAP_START_DIRECTED_ADV_PEER_RPA) != 0U) {
+		if (!IS_ENABLED(CONFIG_BT_PRIVACY)) {
+			return BTP_STATUS_FAILED;
+		}
+
 		for (int i = 0; i < CONFIG_BT_MAX_PAIRED; i++) {
 			if (bt_addr_le_eq(&cp->address, &peers_with_car[i].addr) &&
 			    peers_with_car[i].supported) {
-				adv_param.options |= BT_LE_ADV_OPT_DIR_ADDR_RPA;
-				adv_param.peer = &cp->address;
-				if ((options & BTP_GAP_START_DIRECTED_ADV_HD) == 0U) {
-					adv_param.options |= BT_LE_ADV_OPT_DIR_MODE_LOW_DUTY;
-				}
+				peer_car_supported = true;
 				break;
 			}
 		}
-	} else {
-		adv_param.peer = &cp->address;
-		if ((options & BTP_GAP_START_DIRECTED_ADV_HD) == 0U) {
-			adv_param.options |= BT_LE_ADV_OPT_DIR_MODE_LOW_DUTY;
+
+		if (peer_car_supported == false) {
+			LOG_WRN("Peer doesn't support CAR");
+			return BTP_STATUS_FAILED;
 		}
+
+		adv_param.options |= BT_LE_ADV_OPT_DIR_ADDR_RPA;
 	}
 
+	if ((options & BTP_GAP_START_DIRECTED_ADV_HD) == 0U) {
+		adv_param.options |= BT_LE_ADV_OPT_DIR_MODE_LOW_DUTY;
+	}
+
+	adv_param.peer = &cp->address;
+
 	if (bt_le_adv_start(&adv_param, NULL, 0, NULL, 0) < 0) {
 		LOG_ERR("Failed to start advertising");
 		return BTP_STATUS_FAILED;