Bluetooth: ISO: Use defer setup to separate PA sync and BIG sync

This commit implements defer setup support for the Broadcast Sink
scenario: By setting defer setup on a broadcast socket before calling
listen, the user is able to trigger the PA sync and BIG sync procedures
separately.

This is useful if the user first wants to synchronize to the periodic
advertising transmitted by a Broadcast Source, and trigger the BIG sync
procedure later on.

If defer setup is set, once a PA sync established event arrives, a new
hcon is created and notified to the ISO layer. A child socket associated
with the PA sync connection will be added to the accept queue of the
listening socket.

Once the accept call returns the fd for the PA sync child socket, the
user should call read on that fd. This will trigger the BIG create sync
procedure, and the PA sync socket will become a listening socket itself.

When the BIG sync established event is notified to the ISO layer, the
bis connections will be added to the accept queue of the PA sync parent.
The user should call accept on the PA sync socket to get the final bis
connections.

Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index c53d74236e3a..6fb055e3c595 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -978,6 +978,8 @@ enum {
 	HCI_CONN_CREATE_CIS,
 	HCI_CONN_BIG_SYNC,
 	HCI_CONN_BIG_SYNC_FAILED,
+	HCI_CONN_PA_SYNC,
+	HCI_CONN_PA_SYNC_FAILED,
 };
 
 static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
@@ -1300,7 +1302,7 @@ static inline struct hci_conn *hci_conn_hash_lookup_big_any_dst(struct hci_dev *
 		if (c->type != ISO_LINK)
 			continue;
 
-		if (handle == c->iso_qos.bcast.big) {
+		if (handle != BT_ISO_QOS_BIG_UNSET && handle == c->iso_qos.bcast.big) {
 			rcu_read_unlock();
 			return c;
 		}
@@ -1311,6 +1313,29 @@ static inline struct hci_conn *hci_conn_hash_lookup_big_any_dst(struct hci_dev *
 	return NULL;
 }
 
+static inline struct hci_conn *
+hci_conn_hash_lookup_pa_sync(struct hci_dev *hdev, __u8 big)
+{
+	struct hci_conn_hash *h = &hdev->conn_hash;
+	struct hci_conn  *c;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(c, &h->list, list) {
+		if (c->type != ISO_LINK ||
+			!test_bit(HCI_CONN_PA_SYNC, &c->flags))
+			continue;
+
+		if (c->iso_qos.bcast.big == big) {
+			rcu_read_unlock();
+			return c;
+		}
+	}
+	rcu_read_unlock();
+
+	return NULL;
+}
+
 static inline struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
 							__u8 type, __u16 state)
 {
@@ -1435,7 +1460,8 @@ struct hci_conn *hci_connect_bis(struct hci_dev *hdev, bdaddr_t *dst,
 				 __u8 data_len, __u8 *data);
 int hci_pa_create_sync(struct hci_dev *hdev, bdaddr_t *dst, __u8 dst_type,
 		       __u8 sid, struct bt_iso_qos *qos);
-int hci_le_big_create_sync(struct hci_dev *hdev, struct bt_iso_qos *qos,
+int hci_le_big_create_sync(struct hci_dev *hdev, struct hci_conn *hcon,
+			   struct bt_iso_qos *qos,
 			   __u16 sync_handle, __u8 num_bis, __u8 bis[]);
 int hci_conn_check_link_mode(struct hci_conn *conn);
 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level);