Bluetooth: Track the current configured random address

For Bluetooth controllers with LE support, track the value of the
currently configured random address. It is important to know what
the current random address is to avoid unneeded attempts to set
a new address. This will become important when introducing the
LE privacy support in the future.

In addition expose the current configured random address via
debugfs for debugging purposes.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index b25a36c..877330b 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -548,6 +548,29 @@
 DEFINE_SIMPLE_ATTRIBUTE(sniff_max_interval_fops, sniff_max_interval_get,
 			sniff_max_interval_set, "%llu\n");
 
+static int random_address_show(struct seq_file *f, void *p)
+{
+	struct hci_dev *hdev = f->private;
+
+	hci_dev_lock(hdev);
+	seq_printf(f, "%pMR\n", &hdev->random_addr);
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+static int random_address_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, random_address_show, inode->i_private);
+}
+
+static const struct file_operations random_address_fops = {
+	.open		= random_address_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 static int static_address_show(struct seq_file *f, void *p)
 {
 	struct hci_dev *hdev = f->private;
@@ -1557,6 +1580,8 @@
 	}
 
 	if (lmp_le_capable(hdev)) {
+		debugfs_create_file("random_address", 0444, hdev->debugfs,
+				    hdev, &random_address_fops);
 		debugfs_create_file("static_address", 0444, hdev->debugfs,
 				    hdev, &static_address_fops);
 
@@ -2205,6 +2230,7 @@
 
 	memset(hdev->eir, 0, sizeof(hdev->eir));
 	memset(hdev->dev_class, 0, sizeof(hdev->dev_class));
+	bacpy(&hdev->random_addr, BDADDR_ANY);
 
 	hci_req_unlock(hdev);