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, 127 insertions, 33 deletions

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 3c03e49422c7..2a2c37789e1f 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -51,6 +51,7 @@ static void iso_sock_kill(struct sock *sk);
 /* iso_pinfo flags values */
 enum {
 	BT_SK_BIG_SYNC,
+	BT_SK_PA_SYNC,
 };
 
 struct iso_pinfo {
@@ -75,6 +76,8 @@ static struct bt_iso_qos default_qos;
 
 static bool check_ucast_qos(struct bt_iso_qos *qos);
 static bool check_bcast_qos(struct bt_iso_qos *qos);
+static bool iso_match_sid(struct sock *sk, void *data);
+static void iso_sock_disconn(struct sock *sk);
 
 /* ---- ISO timers ---- */
 #define ISO_CONN_TIMEOUT	(HZ * 40)
@@ -598,6 +601,15 @@ static void iso_sock_cleanup_listen(struct sock *parent)
 		iso_sock_kill(sk);
 	}
 
+	/* If listening socket stands for a PA sync connection,
+	 * properly disconnect the hcon and socket.
+	 */
+	if (iso_pi(parent)->conn && iso_pi(parent)->conn->hcon &&
+	    test_bit(HCI_CONN_PA_SYNC, &iso_pi(parent)->conn->hcon->flags)) {
+		iso_sock_disconn(parent);
+		return;
+	}
+
 	parent->sk_state  = BT_CLOSED;
 	sock_set_flag(parent, SOCK_ZAPPED);
 }
@@ -619,6 +631,16 @@ static void iso_sock_kill(struct sock *sk)
 	sock_put(sk);
 }
 
+static void iso_sock_disconn(struct sock *sk)
+{
+	sk->sk_state = BT_DISCONN;
+	iso_sock_set_timer(sk, ISO_DISCONN_TIMEOUT);
+	iso_conn_lock(iso_pi(sk)->conn);
+	hci_conn_drop(iso_pi(sk)->conn->hcon);
+	iso_pi(sk)->conn->hcon = NULL;
+	iso_conn_unlock(iso_pi(sk)->conn);
+}
+
 static void __iso_sock_close(struct sock *sk)
 {
 	BT_DBG("sk %p state %d socket %p", sk, sk->sk_state, sk->sk_socket);
@@ -631,20 +653,19 @@ static void __iso_sock_close(struct sock *sk)
 	case BT_CONNECT:
 	case BT_CONNECTED:
 	case BT_CONFIG:
-		if (iso_pi(sk)->conn->hcon) {
-			sk->sk_state = BT_DISCONN;
-			iso_sock_set_timer(sk, ISO_DISCONN_TIMEOUT);
-			iso_conn_lock(iso_pi(sk)->conn);
-			hci_conn_drop(iso_pi(sk)->conn->hcon);
-			iso_pi(sk)->conn->hcon = NULL;
-			iso_conn_unlock(iso_pi(sk)->conn);
-		} else {
+		if (iso_pi(sk)->conn->hcon)
+			iso_sock_disconn(sk);
+		else
 			iso_chan_del(sk, ECONNRESET);
-		}
 		break;
 
 	case BT_CONNECT2:
-		iso_chan_del(sk, ECONNRESET);
+		if (iso_pi(sk)->conn->hcon &&
+		    (test_bit(HCI_CONN_PA_SYNC, &iso_pi(sk)->conn->hcon->flags) ||
+		    test_bit(HCI_CONN_PA_SYNC_FAILED, &iso_pi(sk)->conn->hcon->flags)))
+			iso_sock_disconn(sk);
+		else
+			iso_chan_del(sk, ECONNRESET);
 		break;
 	case BT_DISCONN:
 		iso_chan_del(sk, ECONNRESET);
@@ -1139,6 +1160,29 @@ static void iso_conn_defer_accept(struct hci_conn *conn)
 	hci_send_cmd(hdev, HCI_OP_LE_ACCEPT_CIS, sizeof(cp), &cp);
 }
 
+static void iso_conn_big_sync(struct sock *sk)
+{
+	int err;
+	struct hci_dev *hdev;
+
+	hdev = hci_get_route(&iso_pi(sk)->dst, &iso_pi(sk)->src,
+			     iso_pi(sk)->src_type);
+
+	if (!hdev)
+		return;
+
+	if (!test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
+		err = hci_le_big_create_sync(hdev, iso_pi(sk)->conn->hcon,
+					     &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);
+	}
+}
+
 static int iso_sock_recvmsg(struct socket *sock, struct msghdr *msg,
 			    size_t len, int flags)
 {
@@ -1151,8 +1195,15 @@ static int iso_sock_recvmsg(struct socket *sock, struct msghdr *msg,
 		lock_sock(sk);
 		switch (sk->sk_state) {
 		case BT_CONNECT2:
-			iso_conn_defer_accept(pi->conn->hcon);
-			sk->sk_state = BT_CONFIG;
+			if (pi->conn->hcon &&
+			    test_bit(HCI_CONN_PA_SYNC, &pi->conn->hcon->flags)) {
+				iso_conn_big_sync(sk);
+				sk->sk_state = BT_LISTEN;
+				set_bit(BT_SK_PA_SYNC, &iso_pi(sk)->flags);
+			} else {
+				iso_conn_defer_accept(pi->conn->hcon);
+				sk->sk_state = BT_CONFIG;
+			}
 			release_sock(sk);
 			return 0;
 		case BT_CONNECT:
@@ -1513,11 +1564,17 @@ static bool iso_match_big(struct sock *sk, void *data)
 	return ev->handle == iso_pi(sk)->qos.bcast.big;
 }
 
+static bool iso_match_pa_sync_flag(struct sock *sk, void *data)
+{
+	return test_bit(BT_SK_PA_SYNC, &iso_pi(sk)->flags);
+}
+
 static void iso_conn_ready(struct iso_conn *conn)
 {
-	struct sock *parent;
+	struct sock *parent = NULL;
 	struct sock *sk = conn->sk;
-	struct hci_ev_le_big_sync_estabilished *ev;
+	struct hci_ev_le_big_sync_estabilished *ev = NULL;
+	struct hci_ev_le_pa_sync_established *ev2 = NULL;
 	struct hci_conn *hcon;
 
 	BT_DBG("conn %p", conn);
@@ -1529,15 +1586,32 @@ static void iso_conn_ready(struct iso_conn *conn)
 		if (!hcon)
 			return;
 
-		ev = hci_recv_event_data(hcon->hdev,
-					 HCI_EVT_LE_BIG_SYNC_ESTABILISHED);
-		if (ev)
+		if (test_bit(HCI_CONN_BIG_SYNC, &hcon->flags) ||
+		    test_bit(HCI_CONN_BIG_SYNC_FAILED, &hcon->flags)) {
+			ev = hci_recv_event_data(hcon->hdev,
+						 HCI_EVT_LE_BIG_SYNC_ESTABILISHED);
+
+			/* Get reference to PA sync parent socket, if it exists */
 			parent = iso_get_sock_listen(&hcon->src,
 						     &hcon->dst,
-						     iso_match_big, ev);
-		else
+						     iso_match_pa_sync_flag, NULL);
+			if (!parent && ev)
+				parent = iso_get_sock_listen(&hcon->src,
+							     &hcon->dst,
+							     iso_match_big, ev);
+		} else if (test_bit(HCI_CONN_PA_SYNC, &hcon->flags) ||
+				test_bit(HCI_CONN_PA_SYNC_FAILED, &hcon->flags)) {
+			ev2 = hci_recv_event_data(hcon->hdev,
+						  HCI_EV_LE_PA_SYNC_ESTABLISHED);
+			if (ev2)
+				parent = iso_get_sock_listen(&hcon->src,
+							     &hcon->dst,
+							     iso_match_sid, ev2);
+		}
+
+		if (!parent)
 			parent = iso_get_sock_listen(&hcon->src,
-						     BDADDR_ANY, NULL, NULL);
+							BDADDR_ANY, NULL, NULL);
 
 		if (!parent)
 			return;
@@ -1554,11 +1628,17 @@ static void iso_conn_ready(struct iso_conn *conn)
 		iso_sock_init(sk, parent);
 
 		bacpy(&iso_pi(sk)->src, &hcon->src);
-		iso_pi(sk)->src_type = hcon->src_type;
+
+		/* Convert from HCI to three-value type */
+		if (hcon->src_type == ADDR_LE_DEV_PUBLIC)
+			iso_pi(sk)->src_type = BDADDR_LE_PUBLIC;
+		else
+			iso_pi(sk)->src_type = BDADDR_LE_RANDOM;
 
 		/* If hcon has no destination address (BDADDR_ANY) it means it
-		 * was created by HCI_EV_LE_BIG_SYNC_ESTABILISHED so we need to
-		 * initialize using the parent socket destination address.
+		 * was created by HCI_EV_LE_BIG_SYNC_ESTABILISHED or
+		 * HCI_EV_LE_PA_SYNC_ESTABLISHED so we need to initialize using
+		 * the parent socket destination address.
 		 */
 		if (!bacmp(&hcon->dst, BDADDR_ANY)) {
 			bacpy(&hcon->dst, &iso_pi(parent)->dst);
@@ -1566,13 +1646,21 @@ static void iso_conn_ready(struct iso_conn *conn)
 			hcon->sync_handle = iso_pi(parent)->sync_handle;
 		}
 
+		if (ev2 && !ev2->status) {
+			iso_pi(sk)->sync_handle = iso_pi(parent)->sync_handle;
+			iso_pi(sk)->qos = iso_pi(parent)->qos;
+			iso_pi(sk)->bc_num_bis = iso_pi(parent)->bc_num_bis;
+			memcpy(iso_pi(sk)->bc_bis, iso_pi(parent)->bc_bis, ISO_MAX_NUM_BIS);
+		}
+
 		bacpy(&iso_pi(sk)->dst, &hcon->dst);
 		iso_pi(sk)->dst_type = hcon->dst_type;
 
 		hci_conn_hold(hcon);
 		iso_chan_add(conn, sk, parent);
 
-		if (ev && ((struct hci_evt_le_big_sync_estabilished *)ev)->status) {
+		if ((ev && ((struct hci_evt_le_big_sync_estabilished *)ev)->status) ||
+		    (ev2 && ev2->status)) {
 			/* Trigger error signal on child socket */
 			sk->sk_err = ECONNREFUSED;
 			sk->sk_error_report(sk);
@@ -1630,7 +1718,7 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 	if (ev1) {
 		sk = iso_get_sock_listen(&hdev->bdaddr, bdaddr, iso_match_sid,
 					 ev1);
-		if (sk)
+		if (sk && !ev1->status)
 			iso_pi(sk)->sync_handle = le16_to_cpu(ev1->handle);
 
 		goto done;
@@ -1638,16 +1726,21 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 
 	ev2 = hci_recv_event_data(hdev, HCI_EVT_LE_BIG_INFO_ADV_REPORT);
 	if (ev2) {
+		/* Try to get PA sync listening socket, if it exists */
 		sk = iso_get_sock_listen(&hdev->bdaddr, bdaddr,
-					 iso_match_sync_handle, ev2);
+						iso_match_pa_sync_flag, NULL);
+		if (!sk)
+			sk = iso_get_sock_listen(&hdev->bdaddr, bdaddr,
+						 iso_match_sync_handle, ev2);
 		if (sk) {
 			int err;
 
 			if (ev2->num_bis < iso_pi(sk)->bc_num_bis)
 				iso_pi(sk)->bc_num_bis = ev2->num_bis;
 
-			if (!test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
-				err = hci_le_big_create_sync(hdev,
+			if (!test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags) &&
+			    !test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
+				err = hci_le_big_create_sync(hdev, NULL,
 							     &iso_pi(sk)->qos,
 							     iso_pi(sk)->sync_handle,
 							     iso_pi(sk)->bc_num_bis,
@@ -1699,12 +1792,13 @@ static void iso_connect_cfm(struct hci_conn *hcon, __u8 status)
 
 	BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, 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.
+	/* Similar to the success case, if HCI_CONN_BIG_SYNC_FAILED or
+	 * HCI_CONN_PA_SYNC_FAILED is set, queue the failed connection
+	 * into the accept queue of the listening socket and wake up
+	 * userspace, to inform the user about the event.
 	 */
-	if (!status || test_bit(HCI_CONN_BIG_SYNC_FAILED, &hcon->flags)) {
+	if (!status || test_bit(HCI_CONN_BIG_SYNC_FAILED, &hcon->flags) ||
+	    test_bit(HCI_CONN_PA_SYNC_FAILED, &hcon->flags)) {
 		struct iso_conn *conn;
 
 		conn = iso_conn_add(hcon);