1. 17 Apr, 2013 5 commits
    • David Herrmann's avatar
      Bluetooth: allow constant arguments for bacmp()/bacpy() · f53c20e9
      David Herrmann authored
      There is no reason to require the source arguments to be writeable so fix
      this to allow constant source addresses.
      Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      f53c20e9
    • David Herrmann's avatar
      Bluetooth: hidp: test "terminate" before sleeping · e3492dc3
      David Herrmann authored
      The "terminate" flag is guaranteed to be set before the session terminates
      and the handlers are woken up. Hence, we need to add it to the
      sleep-condition.
      
      Note that testing the flags is not enough as nothing prevents us from
      setting the flags again after the session-handler terminated.
      Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      e3492dc3
    • David Herrmann's avatar
      Bluetooth: hidp: remove unused session->state field · dcc07647
      David Herrmann authored
      This field is always BT_CONNECTED. Remove it and set it to BT_CONNECTED in
      hidp_copy_session() unconditionally.
      
      Also note that this field is totally bogus. Userspace can query an
      hidp-session for its state. However, whenever user-space queries us, this
      field should be BT_CONNECTED. If it wasn't BT_CONNECTED, then we would be
      currently cleaning up the session and the session itself would exit in the
      next few milliseconds. Hence, there is no reason to let user-space know
      that the session will exit now if they cannot make _any_ use of that.
      
      Thus, remove the field and let user-space think that a session is always
      BT_CONNECTED as long as they can query it.
      Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      dcc07647
    • David Herrmann's avatar
      Bluetooth: introduce hci_conn ref-counting · 8d12356f
      David Herrmann authored
      We currently do not allow using hci_conn from outside of HCI-core.
      However, several other users could make great use of it. This includes
      HIDP, rfcomm and all other sub-protocols that rely on an active
      connection.
      
      Hence, we now introduce hci_conn ref-counting. We currently never call
      get_device(). put_device() is exclusively used in hci_conn_del_sysfs().
      Hence, we currently never have a greater device-refcnt than 1.
      Therefore, it is safe to move the put_device() call from
      hci_conn_del_sysfs() to hci_conn_del() (it's the only caller). In fact,
      this even fixes a "use-after-free" bug as we access hci_conn after calling
      hci_conn_del_sysfs() in hci_conn_del().
      
      From now on we can add references to hci_conn objects in other layers
      (like l2cap_sock, HIDP, rfcomm, ...) and grab a reference via
      hci_conn_get(). This does _not_ guarantee, that the connection is still
      alive. But, this isn't what we want. We can simply lock the hci_conn
      device and use "device_is_registered(hci_conn->dev)" to test that.
      However, this is hardly necessary as outside users should never rely on
      the HCI connection to be alive, anyway. Instead, they should solely rely
      on the device-object to be available.
      But if sub-devices want the hci_conn object as sysfs parent, they need to
      be notified when the connection drops. This will be introduced in later
      patches with l2cap_users.
      Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      8d12356f
    • David Herrmann's avatar
      Bluetooth: remove unneeded hci_conn_hold/put_device() · fc225c3f
      David Herrmann authored
      hci_conn_hold/put_device() is used to control when hci_conn->dev is no
      longer needed and can be deleted from the system. Lets first look how they
      are currently used throughout the code (excluding HIDP!).
      
      All code that uses hci_conn_hold_device() looks like this:
          ...
          hci_conn_hold_device();
          hci_conn_add_sysfs();
          ...
      On the other side, hci_conn_put_device() is exclusively used in
      hci_conn_del().
      
      So, considering that hci_conn_del() must not be called twice (which would
      fail horribly), we know that hci_conn_put_device() is only called _once_
      (which is in hci_conn_del()).
      On the other hand, hci_conn_add_sysfs() must not be called twice, either
      (it would call device_add twice, which breaks the device, see
      drivers/base/core.c). So we know that hci_conn_hold_device() is also
      called only once (it's only called directly before hci_conn_add_sysfs()).
      
      So hold and put are known to be called only once. That means we can safely
      remove them and directly call hci_conn_del_sysfs() in hci_conn_del().
      
      But there is one issue left: HIDP also uses hci_conn_hold/put_device().
      However, this case can be ignored and simply removed as it is totally
      broken. The issue is, the only thing HIDP delays with
      hci_conn_hold_device() is the removal of the hci_conn->dev from sysfs.
      But, the hci_conn device has no mechanism to get notified when its own
      parent (hci_dev) gets removed from sysfs. hci_dev_hold/put() does _not_
      control when it is removed but only when the device object is created
      and destroyed.
      And hci_dev calls hci_conn_flush_*() when it removes itself from sysfs,
      which itself causes hci_conn_del() to be called, but it does _not_ cause
      hci_conn_del_sysfs() to be called, which is wrong.
      
      Hence, we fix it to call hci_conn_del_sysfs() in hci_conn_del(). This
      guarantees that a hci_conn object is removed from sysfs _before_ its
      parent hci_dev is removed.
      
      The changes to HIDP look scary, wrong and broken. However, if you look at
      the HIDP session management, you will notice they're already broken in the
      exact _same_ way (ever tried "unplugging" HIDP devices? Breaks _all_ the
      time).
      So this patch only makes HIDP look _scary_ and _obviously broken_. It does
      not break HIDP itself, it already is!
      
      See later patches in this series which fix HIDP to use proper
      session-management.
      Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      fc225c3f
  2. 11 Apr, 2013 7 commits
  3. 06 Apr, 2013 2 commits
  4. 04 Apr, 2013 14 commits
  5. 03 Apr, 2013 12 commits