Bluetooth: Add debugfs switch for forcing SMP over BR/EDR

To make it possible to use LE SC functionality over BR/EDR with pre-4.1
controllers (that do not support BR/EDR SC links) it's useful to be able
to force LE SC operations even over a traditional SSP protected link.
This patch adds a debugfs switch to force a special debug flag which is
used to skip the checks for BR/EDR SC support.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

2 files changed, 48 insertions, 0 deletions

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index e56f9099f8e3..569c077778b6 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -163,6 +163,7 @@ enum {
 enum {
         HCI_DUT_MODE,
         HCI_FORCE_SC,
+        HCI_FORCE_LESC,
         HCI_FORCE_STATIC_ADDR,
 };
 
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2fa9f2b2bee3..581e13e9dc32 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -406,6 +406,49 @@ static const struct file_operations force_sc_support_fops = {
         .llseek         = default_llseek,
 };
 
+static ssize_t force_lesc_support_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] = test_bit(HCI_FORCE_LESC, &hdev->dbg_flags) ? 'Y': 'N';
+        buf[1] = '\n';
+        buf[2] = '\0';
+        return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
+}
+
+static ssize_t force_lesc_support_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 == test_bit(HCI_FORCE_LESC, &hdev->dbg_flags))
+                return -EALREADY;
+
+        change_bit(HCI_FORCE_LESC, &hdev->dbg_flags);
+
+        return count;
+}
+
+static const struct file_operations force_lesc_support_fops = {
+        .open           = simple_open,
+        .read           = force_lesc_support_read,
+        .write          = force_lesc_support_write,
+        .llseek         = default_llseek,
+};
+
 static ssize_t sc_only_mode_read(struct file *file, char __user *user_buf,
                                  size_t count, loff_t *ppos)
 {
@@ -1817,6 +1860,10 @@ static int __hci_init(struct hci_dev *hdev)
                                     hdev, &force_sc_support_fops);
                 debugfs_create_file("sc_only_mode", 0444, hdev->debugfs,
                                     hdev, &sc_only_mode_fops);
+                if (lmp_le_capable(hdev))
+                        debugfs_create_file("force_lesc_support", 0644,
+                                            hdev->debugfs, hdev,
+                                            &force_lesc_support_fops);
         }
 
         if (lmp_sniff_capable(hdev)) {