Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next

Johan Hedberg says:

====================
pull request: bluetooth-next 2020-03-29

Here are a few more Bluetooth patches for the 5.7 kernel:

 - Fix assumption of encryption key size when reading fails
 - Add support for DEFER_SETUP with L2CAP Enhanced Credit Based Mode
 - Fix issue with auto-connected devices
 - Fix suspend handling when entering the state fails
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/bluetooth/l2cap.h

@@ -47,6 +47,7 @@
 #define L2CAP_DEFAULT_ACC_LAT		0xFFFFFFFF
 #define L2CAP_BREDR_MAX_PAYLOAD		1019    /* 3-DH5 packet */
 #define L2CAP_LE_MIN_MTU		23
+#define L2CAP_ECRED_CONN_SCID_MAX	5
 
 #define L2CAP_DISC_TIMEOUT		msecs_to_jiffies(100)
 #define L2CAP_DISC_REJ_TIMEOUT		msecs_to_jiffies(5000)
@@ -660,6 +661,7 @@ struct l2cap_ops {
 	void			(*suspend) (struct l2cap_chan *chan);
 	void			(*set_shutdown) (struct l2cap_chan *chan);
 	long			(*get_sndtimeo) (struct l2cap_chan *chan);
+	struct pid		*(*get_peer_pid) (struct l2cap_chan *chan);
 	struct sk_buff		*(*alloc_skb) (struct l2cap_chan *chan,
 					       unsigned long hdr_len,
 					       unsigned long len, int nb);
@@ -983,6 +985,9 @@ void l2cap_chan_set_defaults(struct l2cap_chan *chan);
 int l2cap_ertm_init(struct l2cap_chan *chan);
 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
+typedef void (*l2cap_chan_func_t)(struct l2cap_chan *chan, void *data);
+void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
+		     void *data);
 void l2cap_chan_del(struct l2cap_chan *chan, int err);
 void l2cap_send_conn_req(struct l2cap_chan *chan);
 void l2cap_move_start(struct l2cap_chan *chan);

net/bluetooth/hci_core.c

@@ -3305,6 +3305,15 @@ static void hci_prepare_suspend(struct work_struct *work)
 	hci_dev_unlock(hdev);
 }
 
+static int hci_change_suspend_state(struct hci_dev *hdev,
+				    enum suspended_state next)
+{
+	hdev->suspend_state_next = next;
+	set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
+	queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
+	return hci_suspend_wait_event(hdev);
+}
+
 static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
 				void *data)
 {
@@ -3330,32 +3339,24 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
 		 *    connectable (disabling scanning)
 		 *  - Second, program event filter/whitelist and enable scan
 		 */
-		hdev->suspend_state_next = BT_SUSPEND_DISCONNECT;
-		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
-		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-		ret = hci_suspend_wait_event(hdev);
+		ret = hci_change_suspend_state(hdev, BT_SUSPEND_DISCONNECT);
 
-		/* If the disconnect portion failed, don't attempt to complete
-		 * by configuring the whitelist. The suspend notifier will
-		 * follow a cancelled suspend with a PM_POST_SUSPEND
-		 * notification.
-		 */
-		if (!ret) {
-			hdev->suspend_state_next = BT_SUSPEND_COMPLETE;
-			set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
-			queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-			ret = hci_suspend_wait_event(hdev);
-		}
+		/* Only configure whitelist if disconnect succeeded */
+		if (!ret)
+			ret = hci_change_suspend_state(hdev,
+						       BT_SUSPEND_COMPLETE);
 	} else if (action == PM_POST_SUSPEND) {
-		hdev->suspend_state_next = BT_RUNNING;
-		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
-		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-		ret = hci_suspend_wait_event(hdev);
+		ret = hci_change_suspend_state(hdev, BT_RUNNING);
 	}
 
+	/* If suspend failed, restore it to running */
+	if (ret && action == PM_SUSPEND_PREPARE)
+		hci_change_suspend_state(hdev, BT_RUNNING);
+
 done:
 	return ret ? notifier_from_errno(-EBUSY) : NOTIFY_STOP;
 }
+
 /* Alloc HCI device */
 struct hci_dev *hci_alloc_dev(void)
 {

net/bluetooth/hci_event.c

@@ -2539,16 +2539,17 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 				bt_dev_err(hdev, "no memory for new conn");
 				goto unlock;
 			}
+		} else {
+			if (ev->link_type != SCO_LINK)
+				goto unlock;
+
+			conn = hci_conn_hash_lookup_ba(hdev, ESCO_LINK,
+						       &ev->bdaddr);
+			if (!conn)
+				goto unlock;
+
+			conn->type = SCO_LINK;
 		}
-
-		if (ev->link_type != SCO_LINK)
-			goto unlock;
-
-		conn = hci_conn_hash_lookup_ba(hdev, ESCO_LINK, &ev->bdaddr);
-		if (!conn)
-			goto unlock;
-
-		conn->type = SCO_LINK;
 	}
 
 	if (!ev->status) {
@@ -2962,14 +2963,14 @@ static void read_enc_key_size_complete(struct hci_dev *hdev, u8 status,
 	if (!conn)
 		goto unlock;
 
-	/* If we fail to read the encryption key size, assume maximum
-	 * (which is the same we do also when this HCI command isn't
-	 * supported.
+	/* While unexpected, the read_enc_key_size command may fail. The most
+	 * secure approach is to then assume the key size is 0 to force a
+	 * disconnection.
 	 */
 	if (rp->status) {
 		bt_dev_err(hdev, "failed to read key size for handle %u",
 			   handle);
-		conn->enc_key_size = HCI_LINK_KEY_SIZE;
+		conn->enc_key_size = 0;
 	} else {
 		conn->enc_key_size = rp->key_size;
 	}

net/bluetooth/l2cap_core.c

@@ -678,6 +678,29 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
 }
 EXPORT_SYMBOL_GPL(l2cap_chan_del);
 
+static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
+			      void *data)
+{
+	struct l2cap_chan *chan;
+
+	list_for_each_entry(chan, &conn->chan_l, list) {
+		func(chan, data);
+	}
+}
+
+void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
+		     void *data)
+{
+	if (!conn)
+		return;
+
+	mutex_lock(&conn->chan_lock);
+	__l2cap_chan_list(conn, func, data);
+	mutex_unlock(&conn->chan_lock);
+}
+
+EXPORT_SYMBOL_GPL(l2cap_chan_list);
+
 static void l2cap_conn_update_id_addr(struct work_struct *work)
 {
 	struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
@@ -1356,29 +1379,79 @@ static void l2cap_le_connect(struct l2cap_chan *chan)
 		       sizeof(req), &req);
 }
 
-static void l2cap_ecred_connect(struct l2cap_chan *chan)
-{
-	struct l2cap_conn *conn = chan->conn;
+struct l2cap_ecred_conn_data {
 	struct {
 		struct l2cap_ecred_conn_req req;
-		__le16 scid;
+		__le16 scid[5];
 	} __packed pdu;
+	struct l2cap_chan *chan;
+	struct pid *pid;
+	int count;
+};
+
+static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
+{
+	struct l2cap_ecred_conn_data *conn = data;
+	struct pid *pid;
+
+	if (chan == conn->chan)
+		return;
+
+	if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	pid = chan->ops->get_peer_pid(chan);
+
+	/* Only add deferred channels with the same PID/PSM */
+	if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
+	    chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
+		return;
 
 	if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
 		return;
 
 	l2cap_ecred_init(chan, 0);
 
-	pdu.req.psm     = chan->psm;
-	pdu.req.mtu     = cpu_to_le16(chan->imtu);
-	pdu.req.mps     = cpu_to_le16(chan->mps);
-	pdu.req.credits = cpu_to_le16(chan->rx_credits);
-	pdu.scid        = cpu_to_le16(chan->scid);
+	/* Set the same ident so we can match on the rsp */
+	chan->ident = conn->chan->ident;
+
+	/* Include all channels deferred */
+	conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
+
+	conn->count++;
+}
+
+static void l2cap_ecred_connect(struct l2cap_chan *chan)
+{
+	struct l2cap_conn *conn = chan->conn;
+	struct l2cap_ecred_conn_data data;
+
+	if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
+		return;
+
+	l2cap_ecred_init(chan, 0);
+
+	data.pdu.req.psm     = chan->psm;
+	data.pdu.req.mtu     = cpu_to_le16(chan->imtu);
+	data.pdu.req.mps     = cpu_to_le16(chan->mps);
+	data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
+	data.pdu.scid[0]     = cpu_to_le16(chan->scid);
 
 	chan->ident = l2cap_get_ident(conn);
+	data.pid = chan->ops->get_peer_pid(chan);
+
+	data.count = 1;
+	data.chan = chan;
+	data.pid = chan->ops->get_peer_pid(chan);
+
+	__l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
 
 	l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
-		       sizeof(pdu), &pdu);
+		       sizeof(data.pdu.req) + data.count * sizeof(__le16),
+		       &data.pdu);
 }
 
 static void l2cap_le_start(struct l2cap_chan *chan)
@@ -7693,6 +7766,33 @@ static bool is_valid_psm(u16 psm, u8 dst_type) {
 	return ((psm & 0x0101) == 0x0001);
 }
 
+struct l2cap_chan_data {
+	struct l2cap_chan *chan;
+	struct pid *pid;
+	int count;
+};
+
+static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
+{
+	struct l2cap_chan_data *d = data;
+	struct pid *pid;
+
+	if (chan == d->chan)
+		return;
+
+	if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
+		return;
+
+	pid = chan->ops->get_peer_pid(chan);
+
+	/* Only count deferred channels with the same PID/PSM */
+	if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
+	    chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
+		return;
+
+	d->count++;
+}
+
 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
 		       bdaddr_t *dst, u8 dst_type)
 {
@@ -7812,6 +7912,23 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
 		goto done;
 	}
 
+	if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
+		struct l2cap_chan_data data;
+
+		data.chan = chan;
+		data.pid = chan->ops->get_peer_pid(chan);
+		data.count = 1;
+
+		l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
+
+		/* Check if there isn't too many channels being connected */
+		if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
+			hci_conn_drop(hcon);
+			err = -EPROTO;
+			goto done;
+		}
+	}
+
 	mutex_lock(&conn->chan_lock);
 	l2cap_chan_lock(chan);
 

net/bluetooth/l2cap_sock.c

@@ -1504,6 +1504,13 @@ static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
 	return sk->sk_sndtimeo;
 }
 
+static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)
+{
+	struct sock *sk = chan->data;
+
+	return sk->sk_peer_pid;
+}
+
 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->data;
@@ -1525,6 +1532,7 @@ static const struct l2cap_ops l2cap_chan_ops = {
 	.suspend		= l2cap_sock_suspend_cb,
 	.set_shutdown		= l2cap_sock_set_shutdown_cb,
 	.get_sndtimeo		= l2cap_sock_get_sndtimeo_cb,
+	.get_peer_pid		= l2cap_sock_get_peer_pid_cb,
 	.alloc_skb		= l2cap_sock_alloc_skb_cb,
 };