Re: [PATCH 4/8] Bluetooth: Use the updated key structures for handling LTKs

[Marcel Holtmann <marcel@holtmann.org>]

Hi Vinicius,

> > > This updates all the users of the older way, that was using the
> > > link_keys list to store the SMP keys, to use the new way.
> > > 
> > > This includes defining new types for the keys, we have a type for each
> > > combination of STK/LTK and Master/Slave.
> > > 
> > > Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
> > > ---
> > >  include/net/bluetooth/hci_core.h |   11 +++--
> > >  net/bluetooth/hci_core.c         |   79 ++++++++++++++++++--------------------
> > >  net/bluetooth/hci_event.c        |    9 +++-
> > >  net/bluetooth/smp.c              |   38 +++++++++++-------
> > >  4 files changed, 73 insertions(+), 64 deletions(-)
> > > 
> > > diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> > > index 06eab3f..ae3f653 100644
> > > --- a/include/net/bluetooth/hci_core.h
> > > +++ b/include/net/bluetooth/hci_core.h
> > > @@ -658,12 +658,13 @@ int hci_link_keys_clear(struct hci_dev *hdev);
> > >  struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
> > >  int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
> > >  			bdaddr_t *bdaddr, u8 *val, u8 type, u8 pin_len);
> > > -struct link_key *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8]);
> > > -struct link_key *hci_find_link_key_type(struct hci_dev *hdev,
> > > -					bdaddr_t *bdaddr, u8 type);
> > > -int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
> > > -			u8 key_size, __le16 ediv, u8 rand[8], u8 ltk[16]);
> > > +struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8]);
> > > +int hci_add_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 addr_type, u8 type,
> > > +				int new_key, u8 authenticated, u8 tk[16],
> > > +				u8 enc_size, u16 ediv, u8 rand[8]);
> > >  int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
> > > +struct smp_ltk *hci_find_ltk_addr(struct hci_dev *hdev, bdaddr_t *bdaddr,
> > > +								u8 addr_type);
> > >  int hci_smp_ltks_clear(struct hci_dev *hdev);
> > >  
> > >  int hci_remote_oob_data_clear(struct hci_dev *hdev);
> > > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> > > index a7b2d6b..d00704e 100644
> > > --- a/net/bluetooth/hci_core.c
> > > +++ b/net/bluetooth/hci_core.c
> > > @@ -1222,41 +1222,40 @@ static int hci_persistent_key(struct hci_dev *hdev, struct hci_conn *conn,
> > >  	return 0;
> > >  }
> > >  
> > > -struct link_key *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8])
> > > +/* If the returned key is a STK it should be free'd by the caller */
> > > +struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8])
> > >  {
> > 
> > this kind of API seems to be rather random. We need a bit better
> > semantics here.
> 
> Ok. I can leave the work of removing the STK from the list to the
> caller. Would that make more sense to you? 
> 
> The point is that it doesn't make sense to keep the STK around after
> it was used.

that would be better. Then at least the semantics are clear.

Regards

Marcel