The core spec defines specific response codes for situations when the
received CID is incorrect. Add the defines for these and return them
as appropriate from the LE Connect Request handler function.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The SKB context buffer for HCI request is really not just for requests,
information in their are preserved for the whole HCI layer. So it makes
more sense to actually rename it into bt_cb()->hci and also call it then
struct hci_ctrl.

In addition that allows moving the decoded opcode for outgoing packets
into that struct. So far it was just consuming valuable space from the
main shared items. And opcode are not valid for L2CAP packets.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

There's only one user of this helper which can be replaces with a call
to hci_pend_le_action_lookup() and a check for params->explicit_connect.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Many of the existing LE connection lookups are forced to use
hci_conn_hash_lookup_ba() which doesn't take into account the address
type. What's worse, most of the users don't bother checking that the
returned address type matches what was wanted.

This patch adds a new helper API to look up LE connections based on
their address and address type, paving the way to have the
hci_conn_hash_lookup_ba() users converted to do more precise lookups.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The hci_conn objects don't have a dedicated lock themselves but rely
on the caller to hold the hci_dev lock for most types of access. The
hci_conn_timeout() function has so far sent certain HCI commands based
on the hci_conn state which has been possible without holding the
hci_dev lock.

The recent changes to do LE scanning before connect attempts added
even more operations to hci_conn and hci_dev from hci_conn_timeout,
thereby exposing potential race conditions with the hci_dev and
hci_conn states.

As an example of such a race, here there's a timeout but an
l2cap_sock_connect() call manages to race with the cleanup routine:

[Oct21 08:14] l2cap_chan_timeout: chan ee4b12c0 state BT_CONNECT
[  +0.000004] l2cap_chan_close: chan ee4b12c0 state BT_CONNECT
[  +0.000002] l2cap_chan_del: chan ee4b12c0, conn f3141580, err 111, state BT_CONNECT
[  +0.000002] l2cap_sock_teardown_cb: chan ee4b12c0 state BT_CONNECT
[  +0.000005] l2cap_chan_put: chan ee4b12c0 orig refcnt 4
[  +0.000010] hci_conn_drop: hcon f53d56e0 orig refcnt 1
[  +0.000013] l2cap_chan_put: chan ee4b12c0 orig refcnt 3
[  +0.000063] hci_conn_timeout: hcon f53d56e0 state BT_CONNECT
[  +0.000049] hci_conn_params_del: addr ee:0d:30:09:53:1f (type 1)
[  +0.000002] hci_chan_list_flush: hcon f53d56e0
[  +0.000001] hci_chan_del: hci0 hcon f53d56e0 chan f4e7ccc0
[  +0.004528] l2cap_sock_create: sock e708fc00
[  +0.000023] l2cap_chan_create: chan ee4b1770
[  +0.000001] l2cap_chan_hold: chan ee4b1770 orig refcnt 1
[  +0.000002] l2cap_sock_init: sk ee4b3390
[  +0.000029] l2cap_sock_bind: sk ee4b3390
[  +0.000010] l2cap_sock_setsockopt: sk ee4b3390
[  +0.000037] l2cap_sock_connect: sk ee4b3390
[  +0.000002] l2cap_chan_connect: 00:02:72:d9:e5:8b -> ee:0d:30:09:53:1f (type 2) psm 0x00
[  +0.000002] hci_get_route: 00:02:72:d9:e5:8b -> ee:0d:30:09:53:1f
[  +0.000001] hci_dev_hold: hci0 orig refcnt 8
[  +0.000003] hci_conn_hold: hcon f53d56e0 orig refcnt 0

Above the l2cap_chan_connect() shouldn't have been able to reach the
hci_conn f53d56e0 anymore but since hci_conn_timeout didn't do proper
locking that's not the case. The end result is a reference to hci_conn
that's not in the conn_hash list, resulting in list corruption when
trying to remove it later:

[Oct21 08:15] l2cap_chan_timeout: chan ee4b1770 state BT_CONNECT
[  +0.000004] l2cap_chan_close: chan ee4b1770 state BT_CONNECT
[  +0.000003] l2cap_chan_del: chan ee4b1770, conn f3141580, err 111, state BT_CONNECT
[  +0.000001] l2cap_sock_teardown_cb: chan ee4b1770 state BT_CONNECT
[  +0.000005] l2cap_chan_put: chan ee4b1770 orig refcnt 4
[  +0.000002] hci_conn_drop: hcon f53d56e0 orig refcnt 1
[  +0.000015] l2cap_chan_put: chan ee4b1770 orig refcnt 3
[  +0.000038] hci_conn_timeout: hcon f53d56e0 state BT_CONNECT
[  +0.000003] hci_chan_list_flush: hcon f53d56e0
[  +0.000002] hci_conn_hash_del: hci0 hcon f53d56e0
[  +0.000001] ------------[ cut here ]------------
[  +0.000461] WARNING: CPU: 0 PID: 1782 at lib/list_debug.c:56 __list_del_entry+0x3f/0x71()
[  +0.000839] list_del corruption, f53d56e0->prev is LIST_POISON2 (00000200)

The necessary fix is unfortunately more complicated than just adding
hci_dev_lock/unlock calls to the hci_conn_timeout() call path.
Particularly, the hci_conn_del() API, which expects the hci_dev lock to
be held, performs a cancel_delayed_work_sync(&hcon->disc_work) which
would lead to a deadlock if the hci_conn_timeout() call path tries to
acquire the same lock.

This patch solves the problem by deferring the cleanup work to a
separate work callback. To protect against the hci_dev or hci_conn
going away meanwhile temporary references are taken with the help of
hci_dev_hold() and hci_conn_get().

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.3

Some drivers might have to restore certain settings after the init
procedure has been completed. This driver callback allows them to hook
into that stage. This callback is run just before the controller is
declared as powered up.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Before the vendor specific setup stage is triggered call back into the
core to trigger an internal notification event. That event is used to
send an index update to the monitor interface. With that specific event
it is possible to update userspace with manufacturer information before
any HCI command has been executed. This is useful for early stage
debugging of vendor specific initialization sequences.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

If the diagnostic settings are not persistent over HCI Reset, then this
quirk can be used to tell the Bluetoth core about it. This will ensure
that the settings are programmed correctly when the controller is
powered up.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

There are LE devices on the market that start off by announcing their
public address and then once paired switch to using private address.
To be interoperable with such devices we should simply trust the fact
that we're receiving an IRK from them to indicate that they may use
private addresses in the future. Instead, simply tie the persistency
to the bonding/no-bonding information the same way as for LTKs and
CSRKs.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This adds a new debugfs entry for enabling and disabling the vendor
diagnostic mode. It is only exposed for drivers that provide the
set_diag driver callback and actually have an option for vendor
specific diagnostic information.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>