Bluetooth: Add automated SSP user confirmation responses

This patch adds automated negative and positive (auto-accept) responses
for Secure Simple Pairing user confirmation requests. The responses are
only sent if the HCI_MGMT flag is set in order not to confuse older user
space versions (without management interface support).

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

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 577d638..514e10e 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2483,14 +2483,47 @@ static inline void hci_user_confirm_request_evt(struct hci_dev *hdev,
                                                        struct sk_buff *skb)
 {
        struct hci_ev_user_confirm_req *ev = (void *) skb->data;
+       int loc_mitm, rem_mitm;
+       struct hci_conn *conn;
 
        BT_DBG("%s", hdev->name);
 
        hci_dev_lock(hdev);
 
-       if (test_bit(HCI_MGMT, &hdev->flags))
-               mgmt_user_confirm_request(hdev->id, &ev->bdaddr, ev->passkey);
+       if (!test_bit(HCI_MGMT, &hdev->flags))
+               goto unlock;
 
+       conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &ev->bdaddr);
+       if (!conn)
+               goto unlock;
+
+       loc_mitm = (conn->auth_type & 0x01);
+       rem_mitm = (conn->remote_auth & 0x01);
+
+       /* If we require MITM but the remote device can't provide that
+        * (it has NoInputNoOutput) then reject the confirmation
+        * request. The only exception is when we're dedicated bonding
+        * initiators (connect_cfm_cb set) since then we always have the MITM
+        * bit set. */
+       if (!conn->connect_cfm_cb && loc_mitm && conn->remote_cap == 0x03) {
+               BT_DBG("Rejecting request: remote device can't provide MITM");
+               hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_NEG_REPLY,
+                                       sizeof(ev->bdaddr), &ev->bdaddr);
+               goto unlock;
+       }
+
+       /* 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");
+               hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_REPLY,
+                                               sizeof(ev->bdaddr), &ev->bdaddr);
+               goto unlock;
+       }
+
+       mgmt_user_confirm_request(hdev->id, &ev->bdaddr, ev->passkey);
+
+unlock:
        hci_dev_unlock(hdev);
 }