1. 09 Sep, 2008 2 commits
    • Marcel Holtmann's avatar
      [Bluetooth] Enforce correct authentication requirements · 09ab6f4c
      Marcel Holtmann authored
      With the introduction of Security Mode 4 and Simple Pairing from the
      Bluetooth 2.1 specification it became mandatory that the initiator
      requires authentication and encryption before any L2CAP channel can
      be established. The only exception here is PSM 1 for the service
      discovery protocol (SDP). It is meant to be used without any encryption
      since it contains only public information. This is how Bluetooth 2.0
      and before handle connections on PSM 1.
      
      For Bluetooth 2.1 devices the pairing procedure differentiates between
      no bonding, general bonding and dedicated bonding. The L2CAP layer
      wrongly uses always general bonding when creating new connections, but it
      should not do this for SDP connections. In this case the authentication
      requirement should be no bonding and the just-works model should be used,
      but in case of non-SDP connection it is required to use general bonding.
      
      If the new connection requires man-in-the-middle (MITM) protection, it
      also first wrongly creates an unauthenticated link key and then later on
      requests an upgrade to an authenticated link key to provide full MITM
      protection. With Simple Pairing the link key generation is an expensive
      operation (compared to Bluetooth 2.0 and before) and doing this twice
      during a connection setup causes a noticeable delay when establishing
      a new connection. This should be avoided to not regress from the expected
      Bluetooth 2.0 connection times. The authentication requirements are known
      up-front and so enforce them.
      
      To fulfill these requirements the hci_connect() function has been extended
      with an authentication requirement parameter that will be stored inside
      the connection information and can be retrieved by userspace at any
      time. This allows the correct IO capabilities exchange and results in
      the expected behavior.
      Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      09ab6f4c
    • Marcel Holtmann's avatar
      [Bluetooth] Fix reference counting during ACL config stage · f1c08ca5
      Marcel Holtmann authored
      The ACL config stage keeps holding a reference count on incoming
      connections when requesting the extended features. This results in
      keeping an ACL link up without any users. The problem here is that
      the Bluetooth specification doesn't define an ownership of the ACL
      link and thus it can happen that the implementation on the initiator
      side doesn't care about disconnecting unused links. In this case the
      acceptor needs to take care of this.
      Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
      f1c08ca5
  2. 28 Aug, 2008 17 commits
  3. 27 Aug, 2008 21 commits