Bluetooth: Add variable SSP auto-accept delay support

Some test systems require an arbitrary delay to the auto-accept test
cases for Secure Simple Pairing in order for the tests to pass.
Previously when this was handled in user space it was worked around by
code modifications and recompilation, but now that it's on the kernel
side it's more convenient if there's a debugfs interface for it.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

4 files changed, 60 insertions, 1 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 2995e2e63512..09b9dd61e370 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -126,6 +126,8 @@ struct hci_dev {
         __u16           sniff_min_interval;
         __u16           sniff_max_interval;
 
+        unsigned int    auto_accept_delay;
+
         unsigned long   quirks;
 
         atomic_t        cmd_cnt;
@@ -246,6 +248,7 @@ struct hci_conn {
 
         struct timer_list disc_timer;
         struct timer_list idle_timer;
+        struct timer_list auto_accept_timer;
 
         struct work_struct work_add;
         struct work_struct work_del;
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 74cd755b38a7..7f5ad8a2b22d 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -269,6 +269,19 @@ static void hci_conn_idle(unsigned long arg)
         hci_conn_enter_sniff_mode(conn);
 }
 
+static void hci_conn_auto_accept(unsigned long arg)
+{
+        struct hci_conn *conn = (void *) arg;
+        struct hci_dev *hdev = conn->hdev;
+
+        hci_dev_lock(hdev);
+
+        hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_REPLY, sizeof(conn->dst),
+                                                                &conn->dst);
+
+        hci_dev_unlock(hdev);
+}
+
 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 {
         struct hci_conn *conn;
@@ -312,6 +325,8 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
 
         setup_timer(&conn->disc_timer, hci_conn_timeout, (unsigned long)conn);
         setup_timer(&conn->idle_timer, hci_conn_idle, (unsigned long)conn);
+        setup_timer(&conn->auto_accept_timer, hci_conn_auto_accept,
+                                                        (unsigned long) conn);
 
         atomic_set(&conn->refcnt, 0);
 
@@ -342,6 +357,8 @@ int hci_conn_del(struct hci_conn *conn)
 
         del_timer(&conn->disc_timer);
 
+        del_timer(&conn->auto_accept_timer);
+
         if (conn->type == ACL_LINK) {
                 struct hci_conn *sco = conn->link;
                 if (sco)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 514e10e1e0ff..a479389668ef 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2515,7 +2515,15 @@ static inline void hci_user_confirm_request_evt(struct hci_dev *hdev,
         /* If no side requires MITM protection; auto-accept */
         if ((!loc_mitm || conn->remote_cap == 0x03) &&
                                 (!rem_mitm || conn->io_capability == 0x03)) {
-                BT_DBG("Auto-accept of user confirmation");
+                BT_DBG("Auto-accept of user confirmation with %ums delay",
+                                                hdev->auto_accept_delay);
+
+                if (hdev->auto_accept_delay > 0) {
+                        int delay = msecs_to_jiffies(hdev->auto_accept_delay);
+                        mod_timer(&conn->auto_accept_timer, jiffies + delay);
+                        goto unlock;
+                }
+
                 hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_REPLY,
                                                 sizeof(ev->bdaddr), &ev->bdaddr);
                 goto unlock;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 8775933ea837..a6c3aa8be1f7 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -511,6 +511,35 @@ static const struct file_operations uuids_fops = {
         .release        = single_release,
 };
 
+static int auto_accept_delay_set(void *data, u64 val)
+{
+        struct hci_dev *hdev = data;
+
+        hci_dev_lock_bh(hdev);
+
+        hdev->auto_accept_delay = val;
+
+        hci_dev_unlock_bh(hdev);
+
+        return 0;
+}
+
+static int auto_accept_delay_get(void *data, u64 *val)
+{
+        struct hci_dev *hdev = data;
+
+        hci_dev_lock_bh(hdev);
+
+        *val = hdev->auto_accept_delay;
+
+        hci_dev_unlock_bh(hdev);
+
+        return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(auto_accept_delay_fops, auto_accept_delay_get,
+                                        auto_accept_delay_set, "%llu\n");
+
 int hci_register_sysfs(struct hci_dev *hdev)
 {
         struct device *dev = &hdev->dev;
@@ -545,6 +574,8 @@ int hci_register_sysfs(struct hci_dev *hdev)
 
         debugfs_create_file("uuids", 0444, hdev->debugfs, hdev, &uuids_fops);
 
+        debugfs_create_file("auto_accept_delay", 0444, hdev->debugfs, hdev,
+                                                &auto_accept_delay_fops);
         return 0;
 }