Bluetooth: debugfs option to unset MITM flag

The BT qualification test SM/MAS/PKE/BV-01-C needs us to turn off
the MITM flag when pairing, and at the same time also set the io
capability to something other than no input no output.

Currently the MITM flag is only unset when the io capability is set
to no input no output, therefore the test cannot be executed.

This patch introduces a debugfs option to force MITM flag to be
turned off.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/net/bluetooth/hci_debugfs.c b/net/bluetooth/hci_debugfs.c
index 6b1314c738b8..5e8af2658e44 100644
--- a/net/bluetooth/hci_debugfs.c
+++ b/net/bluetooth/hci_debugfs.c
@@ -1075,6 +1075,50 @@ DEFINE_SIMPLE_ATTRIBUTE(auth_payload_timeout_fops,
 			auth_payload_timeout_get,
 			auth_payload_timeout_set, "%llu\n");
 
+static ssize_t force_no_mitm_read(struct file *file,
+				  char __user *user_buf,
+				  size_t count, loff_t *ppos)
+{
+	struct hci_dev *hdev = file->private_data;
+	char buf[3];
+
+	buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_NO_MITM) ? 'Y' : 'N';
+	buf[1] = '\n';
+	buf[2] = '\0';
+	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
+}
+
+static ssize_t force_no_mitm_write(struct file *file,
+				   const char __user *user_buf,
+				   size_t count, loff_t *ppos)
+{
+	struct hci_dev *hdev = file->private_data;
+	char buf[32];
+	size_t buf_size = min(count, (sizeof(buf) - 1));
+	bool enable;
+
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+
+	buf[buf_size] = '\0';
+	if (strtobool(buf, &enable))
+		return -EINVAL;
+
+	if (enable == hci_dev_test_flag(hdev, HCI_FORCE_NO_MITM))
+		return -EALREADY;
+
+	hci_dev_change_flag(hdev, HCI_FORCE_NO_MITM);
+
+	return count;
+}
+
+static const struct file_operations force_no_mitm_fops = {
+	.open		= simple_open,
+	.read		= force_no_mitm_read,
+	.write		= force_no_mitm_write,
+	.llseek		= default_llseek,
+};
+
 DEFINE_QUIRK_ATTRIBUTE(quirk_strict_duplicate_filter,
 		       HCI_QUIRK_STRICT_DUPLICATE_FILTER);
 DEFINE_QUIRK_ATTRIBUTE(quirk_simultaneous_discovery,
@@ -1134,6 +1178,8 @@ void hci_debugfs_create_le(struct hci_dev *hdev)
 			    &max_key_size_fops);
 	debugfs_create_file("auth_payload_timeout", 0644, hdev->debugfs, hdev,
 			    &auth_payload_timeout_fops);
+	debugfs_create_file("force_no_mitm", 0644, hdev->debugfs, hdev,
+			    &force_no_mitm_fops);
 
 	debugfs_create_file("quirk_strict_duplicate_filter", 0644,
 			    hdev->debugfs, hdev,