Bluetooth: ISO: Add ISO BIS bitfield check macro

Checks validity of ISO BIS bitfield (BIT(0)|...|BIT(30))

Signed-off-by: Lars Knudsen <[email protected]>

Author: larsgk

include/zephyr/bluetooth/iso.h

@@ -140,6 +140,14 @@ extern "C" {
 /** Maximum pre-transmission offset */
 #define BT_ISO_PTO_MAX              0x0FU
 
+/**
+ * @brief Check if ISO BIS bitfield is valid (BT_ISO_BIS_INDEX_BIT(1)|..|BT_ISO_BIS_INDEX_BIT(31))
+ *
+ * @param _bis_bitfield BIS index bitfield (uint32)
+ */
+#define BT_ISO_VALID_BIS_BITFIELD(_bis_bitfield)                                                   \
+	((_bis_bitfield) != 0U && (_bis_bitfield) <= BIT_MASK(BT_ISO_BIS_INDEX_MAX))
+
 /**
  * @brief Life-span states of ISO channel. Used only by internal APIs dealing with setting channel
  * to proper state depending on operational context.

subsys/bluetooth/host/iso.c

@@ -3316,7 +3316,7 @@ int bt_iso_big_sync(struct bt_le_per_adv_sync *sync, struct bt_iso_big_sync_para
 		return -EINVAL;
 	}
 
-	CHECKIF(param->bis_bitfield == 0U || param->bis_bitfield > BIT_MASK(BT_ISO_BIS_INDEX_MAX)) {
+	CHECKIF(!BT_ISO_VALID_BIS_BITFIELD(param->bis_bitfield)) {
 		LOG_DBG("Invalid BIS bitfield 0x%08x", param->bis_bitfield);
 		return -EINVAL;
 	}