Bluetooth: Add le_auto_conn file on debugfs

This patch adds to debugfs the le_auto_conn file. This file will be
used to test LE auto connection infrastructure.

This file accept writes in the following format:
  "add <address> <address_type> [auto_connect]"
  "del <address> <address_type>"
  "clr"

The <address type> values are:
  * 0 for public address
  * 1 for random address

The [auto_connect] values are (for more details see struct hci_
conn_params):
  * 0 for disabled (default)
  * 1 for always
  * 2 for link loss

So for instance, if you want the kernel autonomously establishes
connections with device AA:BB:CC:DD:EE:FF (public address) every
time the device enters in connectable mode (starts advertising),
you should run the command:
$ echo "add AA:BB:CC:DD:EE:FF 0 1" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

To delete the connection parameters for that device, run the command:
$ echo "del AA:BB:CC:DD:EE:FF 0" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

To clear the connection parameters list, run the command:
$ echo "clr" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

Finally. to get the list of connection parameters configured in kernel,
read the le_auto_conn file:
$ cat /sys/kernel/debug/bluetooth/hci0/le_auto_conn

This file is created only if LE is enabled.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 111 insertions, 0 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 6d83ca040970..0b96f20238d8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -896,6 +896,115 @@ static const struct file_operations lowpan_debugfs_fops = {
         .llseek         = default_llseek,
 };
 
+static int le_auto_conn_show(struct seq_file *sf, void *ptr)
+{
+        struct hci_dev *hdev = sf->private;
+        struct hci_conn_params *p;
+
+        hci_dev_lock(hdev);
+
+        list_for_each_entry(p, &hdev->le_conn_params, list) {
+                seq_printf(sf, "%pMR %u %u\n", &p->addr, p->addr_type,
+                           p->auto_connect);
+        }
+
+        hci_dev_unlock(hdev);
+
+        return 0;
+}
+
+static int le_auto_conn_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, le_auto_conn_show, inode->i_private);
+}
+
+static ssize_t le_auto_conn_write(struct file *file, const char __user *data,
+                                  size_t count, loff_t *offset)
+{
+        struct seq_file *sf = file->private_data;
+        struct hci_dev *hdev = sf->private;
+        u8 auto_connect = 0;
+        bdaddr_t addr;
+        u8 addr_type;
+        char *buf;
+        int err = 0;
+        int n;
+
+        /* Don't allow partial write */
+        if (*offset != 0)
+                return -EINVAL;
+
+        if (count < 3)
+                return -EINVAL;
+
+        buf = kzalloc(count, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        if (copy_from_user(buf, data, count)) {
+                err = -EFAULT;
+                goto done;
+        }
+
+        if (memcmp(buf, "add", 3) == 0) {
+                n = sscanf(&buf[4], "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu %hhu",
+                           &addr.b[5], &addr.b[4], &addr.b[3], &addr.b[2],
+                           &addr.b[1], &addr.b[0], &addr_type,
+                           &auto_connect);
+
+                if (n < 7) {
+                        err = -EINVAL;
+                        goto done;
+                }
+
+                hci_dev_lock(hdev);
+                err = hci_conn_params_add(hdev, &addr, addr_type, auto_connect,
+                                          hdev->le_conn_min_interval,
+                                          hdev->le_conn_max_interval);
+                hci_dev_unlock(hdev);
+
+                if (err)
+                        goto done;
+        } else if (memcmp(buf, "del", 3) == 0) {
+                n = sscanf(&buf[4], "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
+                           &addr.b[5], &addr.b[4], &addr.b[3], &addr.b[2],
+                           &addr.b[1], &addr.b[0], &addr_type);
+
+                if (n < 7) {
+                        err = -EINVAL;
+                        goto done;
+                }
+
+                hci_dev_lock(hdev);
+                hci_conn_params_del(hdev, &addr, addr_type);
+                hci_dev_unlock(hdev);
+        } else if (memcmp(buf, "clr", 3) == 0) {
+                hci_dev_lock(hdev);
+                hci_conn_params_clear(hdev);
+                hci_pend_le_conns_clear(hdev);
+                hci_update_background_scan(hdev);
+                hci_dev_unlock(hdev);
+        } else {
+                err = -EINVAL;
+        }
+
+done:
+        kfree(buf);
+
+        if (err)
+                return err;
+        else
+                return count;
+}
+
+static const struct file_operations le_auto_conn_fops = {
+        .open           = le_auto_conn_open,
+        .read           = seq_read,
+        .write          = le_auto_conn_write,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
 /* ---- HCI requests ---- */
 
 static void hci_req_sync_complete(struct hci_dev *hdev, u8 result)
@@ -1694,6 +1803,8 @@ static int __hci_init(struct hci_dev *hdev)
                                     hdev, &adv_channel_map_fops);
                 debugfs_create_file("6lowpan", 0644, hdev->debugfs, hdev,
                                     &lowpan_debugfs_fops);
+                debugfs_create_file("le_auto_conn", 0644, hdev->debugfs, hdev,
+                                    &le_auto_conn_fops);
         }
 
         return 0;