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, 37 insertions, 4 deletions

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 559b6080706c..b4b72070f5f6 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -6581,20 +6581,39 @@ static void hci_le_pa_sync_estabilished_evt(struct hci_dev *hdev, void *data,
 	struct hci_ev_le_pa_sync_established *ev = data;
 	int mask = hdev->link_mode;
 	__u8 flags = 0;
+	struct hci_conn *bis;
 
 	bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);
 
-	if (ev->status)
-		return;
-
 	hci_dev_lock(hdev);
 
 	hci_dev_clear_flag(hdev, HCI_PA_SYNC);
 
 	mask |= hci_proto_connect_ind(hdev, &ev->bdaddr, ISO_LINK, &flags);
-	if (!(mask & HCI_LM_ACCEPT))
+	if (!(mask & HCI_LM_ACCEPT)) {
 		hci_le_pa_term_sync(hdev, ev->handle);
+		goto unlock;
+	}
+
+	if (!(flags & HCI_PROTO_DEFER))
+		goto unlock;
+
+	/* Add connection to indicate the PA sync event */
+	bis = hci_conn_add(hdev, ISO_LINK, BDADDR_ANY,
+			   HCI_ROLE_SLAVE);
 
+	if (!bis)
+		goto unlock;
+
+	if (ev->status)
+		set_bit(HCI_CONN_PA_SYNC_FAILED, &bis->flags);
+	else
+		set_bit(HCI_CONN_PA_SYNC, &bis->flags);
+
+	/* Notify connection to iso layer */
+	hci_connect_cfm(bis, ev->status);
+
+unlock:
 	hci_dev_unlock(hdev);
 }
 
@@ -7045,6 +7064,7 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
 {
 	struct hci_evt_le_big_sync_estabilished *ev = data;
 	struct hci_conn *bis;
+	struct hci_conn *pa_sync;
 	int i;
 
 	bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);
@@ -7055,6 +7075,15 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
 
 	hci_dev_lock(hdev);
 
+	if (!ev->status) {
+		pa_sync = hci_conn_hash_lookup_pa_sync(hdev, ev->handle);
+		if (pa_sync)
+			/* Also mark the BIG sync established event on the
+			 * associated PA sync hcon
+			 */
+			set_bit(HCI_CONN_BIG_SYNC, &pa_sync->flags);
+	}
+
 	for (i = 0; i < ev->num_bis; i++) {
 		u16 handle = le16_to_cpu(ev->bis[i]);
 		__le32 interval;
@@ -7068,6 +7097,10 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
 			bis->handle = handle;
 		}
 
+		if (ev->status != 0x42)
+			/* Mark PA sync as established */
+			set_bit(HCI_CONN_PA_SYNC, &bis->flags);
+
 		bis->iso_qos.bcast.big = ev->handle;
 		memset(&interval, 0, sizeof(interval));
 		memcpy(&interval, ev->latency, sizeof(ev->latency));