[PATCH v4 2/8] Bluetooth: hci_core: Introduce HCI_CONN_FLAG_PAST

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This introduces a new device flag so userspace can indicate if it
wants to enable PAST Receiver for a specific device.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_sync.c         | 55 +++++++++++++++++++++++++++++++-
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 894e01717b55..2a765a0521b4 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -166,6 +166,7 @@ enum hci_conn_flags {
 	HCI_CONN_FLAG_REMOTE_WAKEUP = BIT(0),
 	HCI_CONN_FLAG_DEVICE_PRIVACY = BIT(1),
 	HCI_CONN_FLAG_ADDRESS_RESOLUTION = BIT(2),
+	HCI_CONN_FLAG_PAST = BIT(3),
 };
 typedef u8 hci_conn_flags_t;
 
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 277b2c096195..5051413f1a97 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4324,6 +4324,10 @@ static int hci_le_set_event_mask_sync(struct hci_dev *hdev)
 	if (ll_privacy_capable(hdev))
 		hdev->conn_flags |= HCI_CONN_FLAG_ADDRESS_RESOLUTION;
 
+	/* Mark PAST if supported */
+	if (past_capable(hdev))
+		hdev->conn_flags |= HCI_CONN_FLAG_PAST;
+
 	/* If the controller supports Extended Scanner Filter
 	 * Policies, enable the corresponding event.
 	 */
@@ -7024,10 +7028,41 @@ static void create_pa_complete(struct hci_dev *hdev, void *data, int err)
 	hci_dev_unlock(hdev);
 }
 
+static int hci_le_past_params_sync(struct hci_dev *hdev, struct hci_conn *conn,
+				   struct hci_conn *acl, struct bt_iso_qos *qos)
+{
+	struct hci_cp_le_past_params cp;
+	int err;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.handle = cpu_to_le16(acl->handle);
+	/* An HCI_LE_Periodic_Advertising_Sync_Transfer_Received event is sent
+	 * to the Host. HCI_LE_Periodic_Advertising_Report events will be
+	 * enabled with duplicate filtering enabled.
+	 */
+	cp.mode = 0x03;
+	cp.skip = cpu_to_le16(qos->bcast.skip);
+	cp.sync_timeout = cpu_to_le16(qos->bcast.sync_timeout);
+	cp.cte_type = qos->bcast.sync_cte_type;
+
+	/* HCI_LE_PAST_PARAMS command returns a command complete event so it
+	 * cannot wait for HCI_EV_LE_PAST_RECEIVED.
+	 */
+	err = __hci_cmd_sync_status(hdev, HCI_OP_LE_PAST_PARAMS,
+				    sizeof(cp), &cp, HCI_CMD_TIMEOUT);
+	if (err)
+		return err;
+
+	/* Wait for HCI_EV_LE_PAST_RECEIVED event */
+	return __hci_cmd_sync_status_sk(hdev, HCI_OP_NOP, 0, NULL,
+					HCI_EV_LE_PAST_RECEIVED,
+					conn->conn_timeout, NULL);
+}
+
 static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
 {
 	struct hci_cp_le_pa_create_sync cp;
-	struct hci_conn *conn = data;
+	struct hci_conn *conn = data, *le;
 	struct bt_iso_qos *qos = &conn->iso_qos;
 	int err;
 
@@ -7059,6 +7094,24 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
 
 	hci_update_passive_scan_sync(hdev);
 
+	/* Check if PAST is possible:
+	 *
+	 * 1. Check if an ACL connection with the destination address exists
+	 * 2. Check if that HCI_CONN_FLAG_PAST has been set which indicates that
+	 *    user really intended to use PAST.
+	 */
+	le = hci_conn_hash_lookup_le(hdev, &conn->dst, conn->dst_type);
+	if (le) {
+		struct hci_conn_params *params;
+
+		params = hci_conn_params_lookup(hdev, &le->dst, le->dst_type);
+		if (params && params->flags & HCI_CONN_FLAG_PAST) {
+			err = hci_le_past_params_sync(hdev, conn, le, qos);
+			if (!err)
+				goto done;
+		}
+	}
+
 	/* SID has not been set listen for HCI_EV_LE_EXT_ADV_REPORT to update
 	 * it.
 	 */
-- 
2.51.0