Bluetooth: ISO: Notify user space about failed bis connections

Some use cases require the user to be informed if BIG synchronization
fails. This commit makes it so that even if the BIG sync established
event arrives with error status, a new hconn is added for each BIS,
and the iso layer is notified about the failed connections.

Unsuccesful bis connections will be marked using the
HCI_CONN_BIG_SYNC_FAILED flag. From the iso layer, the POLLERR event
is triggered on the newly allocated bis sockets, before adding them
to the accept list of the parent socket.

From user space, a new fd for each failed bis connection will be
obtained by calling accept. The user should check for the POLLERR
event on the new socket, to determine if the connection was successful
or not.

The HCI_CONN_BIG_SYNC flag has been added to mark whether the BIG sync
has been successfully established. This flag is checked at bis cleanup,
so the HCI LE BIG Terminate Sync command is only issued if needed.

The BT_SK_BIG_SYNC flag indicates if BIG create sync has been called
for a listening socket, to avoid issuing the command everytime a BIGInfo
advertising report is received.

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

1 files changed, 29 insertions, 11 deletions

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 9c41af55f2c7..efac284badbc 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -48,6 +48,11 @@ static void iso_sock_kill(struct sock *sk);
 #define EIR_SERVICE_DATA_LENGTH 4
 #define BASE_MAX_LENGTH (HCI_MAX_PER_AD_LENGTH - EIR_SERVICE_DATA_LENGTH)
 
+/* iso_pinfo flags values */
+enum {
+	BT_SK_BIG_SYNC,
+};
+
 struct iso_pinfo {
 	struct bt_sock		bt;
 	bdaddr_t		src;
@@ -58,7 +63,7 @@ struct iso_pinfo {
 	__u8			bc_num_bis;
 	__u8			bc_bis[ISO_MAX_NUM_BIS];
 	__u16			sync_handle;
-	__u32			flags;
+	unsigned long		flags;
 	struct bt_iso_qos	qos;
 	bool			qos_user_set;
 	__u8			base_len;
@@ -1555,6 +1560,12 @@ static void iso_conn_ready(struct iso_conn *conn)
 		hci_conn_hold(hcon);
 		iso_chan_add(conn, sk, parent);
 
+		if (ev && ((struct hci_evt_le_big_sync_estabilished *)ev)->status) {
+			/* Trigger error signal on child socket */
+			sk->sk_err = ECONNREFUSED;
+			sk->sk_error_report(sk);
+		}
+
 		if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
 			sk->sk_state = BT_CONNECT2;
 		else
@@ -1623,15 +1634,17 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 			if (ev2->num_bis < iso_pi(sk)->bc_num_bis)
 				iso_pi(sk)->bc_num_bis = ev2->num_bis;
 
-			err = hci_le_big_create_sync(hdev,
-						     &iso_pi(sk)->qos,
-						     iso_pi(sk)->sync_handle,
-						     iso_pi(sk)->bc_num_bis,
-						     iso_pi(sk)->bc_bis);
-			if (err) {
-				bt_dev_err(hdev, "hci_le_big_create_sync: %d",
-					   err);
-				sk = NULL;
+			if (!test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
+				err = hci_le_big_create_sync(hdev,
+							     &iso_pi(sk)->qos,
+							     iso_pi(sk)->sync_handle,
+							     iso_pi(sk)->bc_num_bis,
+							     iso_pi(sk)->bc_bis);
+				if (err) {
+					bt_dev_err(hdev, "hci_le_big_create_sync: %d",
+						   err);
+					sk = NULL;
+				}
 			}
 		}
 	} else {
@@ -1674,7 +1687,12 @@ static void iso_connect_cfm(struct hci_conn *hcon, __u8 status)
 
 	BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
 
-	if (!status) {
+	/* Similar to the success case, if HCI_CONN_BIG_SYNC_FAILED is set,
+	 * queue the failed bis connection into the accept queue of the
+	 * listening socket and wake up userspace, to inform the user about
+	 * the BIG sync failed event.
+	 */
+	if (!status || test_bit(HCI_CONN_BIG_SYNC_FAILED, &hcon->flags)) {
 		struct iso_conn *conn;
 
 		conn = iso_conn_add(hcon);