Bluetooth: controller: rework per scan lll to allow filt by CTE type

Periodic advertisement synchronization may be filtered by CTE type.
If particular CTE type is not allowed then depening on filtering policy:
- if filtering policy is off synchronization if terminated
- if filtering policy is on synchronization is continued to
  synchonize with another device from allowed adverisements list.
If synchronization is established and peer device changes CTE type
to one that is not allowed, synchronization should be maintained.

There are two new execution paths. First one is executed when
synchronization is created. In this case CTEILINE is enabled
to parse PDU for CTEInfo field. In this execution path CTE
type is verified. Second execution path does not include
parsing PDU for CTEInfo and verification of CTE type.

Information about sync allowed is added to node_rx instance
that transports received PDU data. In case the sync has to be
terminated the node_rx will not hold PDU data.

Also done event is extended with information about sync
termination if CTE type is not allowed and filtering
policy is off.

Signed-off-by: Piotr Pryga <[email protected]>

Author: ppryga-nordic

subsys/bluetooth/controller/ll_sw/lll.h

@@ -284,6 +284,9 @@ struct node_rx_ftr {
 	uint8_t  aux_lll_sched:1;
 	uint8_t  aux_w4next:1;
 	uint8_t  aux_failed:1;
+#if defined(CONFIG_BT_CTLR_SYNC_PERIODIC)
+	uint8_t sync_status:2;
+#endif /* CONFIG_BT_CTLR_SYNC_PERIODIC */
 
 	uint8_t  phy_flags:1;
 	uint8_t  scan_req:1;
@@ -400,7 +403,13 @@ struct event_done_extra {
 	union {
 		struct {
 			uint16_t trx_cnt;
-			uint8_t  crc_valid;
+			uint8_t  crc_valid:1;
+#if defined(CONFIG_BT_CTLR_SYNC_PERIODIC)
+			/* Used to inform ULL that periodic advertising sync scan should be
+			 * terminated.
+			 */
+			uint8_t  sync_term:1;
+#endif /* CONFIG_BT_CTLR_SYNC_PERIODIC */
 #if defined(CONFIG_BT_CTLR_LE_ENC)
 			uint8_t  mic_state;
 #endif /* CONFIG_BT_CTLR_LE_ENC */

subsys/bluetooth/controller/ll_sw/lll_sync.h

@@ -4,6 +4,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/* Periodic advertisements synchronization status. */
+enum sync_status {
+	SYNC_STAT_FOUND,
+	SYNC_STAT_READY,
+	SYNC_STAT_TERM
+};
+
 struct lll_sync {
 	struct lll_hdr hdr;
 
@@ -12,6 +19,12 @@ struct lll_sync {
 
 	uint8_t phy:3;
 	uint8_t is_rx_enabled:1;
+	/* Bitmask providing not allowed types of CTE. */
+	uint8_t cte_type:5;
+	/* The member is required for filtering by CTE type. If filtering policy is disabled then
+	 * synchronization is terminated for periodic advertisements with wrong CTE type.
+	 */
+	uint8_t filter_policy:1;
 	uint8_t is_aux_sched:1;
 
 	uint16_t skip_prepare;
@@ -43,6 +56,7 @@ struct lll_sync {
 
 int lll_sync_init(void);
 int lll_sync_reset(void);
+void lll_sync_create_prepare(void *param);
 void lll_sync_prepare(void *param);
 
 extern uint16_t ull_sync_lll_handle_get(struct lll_sync *lll);