The Bluetooth stack uses a reference counting for all established ACL
links and if no user (L2CAP connection) is present, the link will be
terminated to save power. The problem part is the dedicated pairing
when using Legacy Pairing (Bluetooth 2.0 and before). At that point
no user is present and pairing attempts will be disconnected within
10 seconds or less. In previous kernel version this was not a problem
since the disconnect timeout wasn't triggered on incoming connections
for the first time. However this caused issues with broken host stacks
that kept the connections around after dedicated pairing. When the
support for Simple Pairing got added, the link establishment procedure
needed to be changed and now causes issues when using Legacy Pairing

When using Simple Pairing it is possible to do a proper reference
counting of ACL link users. With Legacy Pairing this is not possible
since the specification is unclear in some areas and too many broken
Bluetooth devices have already been deployed. So instead of trying to
deal with all the broken devices, a special pairing timeout will be
introduced that increases the timeout to 60 seconds when pairing is
triggered.

If a broken devices now puts the stack into an unforeseen state, the
worst that happens is the disconnect timeout triggers after 120 seconds
instead of 4 seconds. This allows successful pairings with legacy and
broken devices now.

Based on a report by Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When attempting to setup eSCO connections it can happen that some link
manager implementations fail to properly negotiate the eSCO parameters
and thus fail the eSCO setup. Normally the link manager is responsible
for the negotiation of the parameters and actually fallback to SCO if
no agreement can be reached. In cases where the link manager is just too
stupid, then at least try to establish a SCO link if eSCO fails.

For the Bluetooth devices with EDR support this includes handling packet
types of EDR basebands. This is particular tricky since for the EDR the
logic of enabling/disabling one specific packet type is turned around.
This fix contains an extra bitmask to disable eSCO EDR packet when
trying to fallback to a SCO connection.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth subsystem was not using the HCI Reset command when doing
device initialization. The Bluetooth 1.0b specification was ambiguous
on how the device firmware was suppose to handle it. Almost every device
was triggering a transport reset at the same time. In case of USB this
ended up in disconnects from the bus.

All modern Bluetooth dongles handle this perfectly fine and a lot of
them actually require that HCI Reset is sent. If not then they are
either stuck in their HID Proxy mode or their internal structures for
inquiry and paging are not correctly setup.

To handle old and new devices smoothly the Bluetooth subsystem contains
a quirk to force the HCI Reset on initialization. However maintaining
such a quirk becomes more and more complicated. This patch turns the
logic around and lets the old devices disable the HCI Reset command.

The only device where the HCI_QUIRK_NO_RESET is still needed are the
original Digianswer devices and dongles with an early CSR firmware.

CSR reported that they fixed this for version 12 firmware. The last
official release of version 11 firmware is build ID 115. The first
version 12 candidate was build ID 117.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With the Simple Pairing support, the authentication requirements are
an explicit setting during the bonding process. Track and enforce the
requirements and allow higher layers like L2CAP and RFCOMM to increase
them if needed.

This patch introduces a new IOCTL that allows to query the current
authentication requirements. It is also possible to detect Simple
Pairing support in the kernel this way.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth technology introduces new features on a regular basis
and for some of them it is important that the hardware on both sides
support them. For features like Simple Pairing it is important that
the host stacks on both sides have switched this feature on. To make
valid decisions, a config stage during ACL link establishment has been
introduced that retrieves remote features and if needed also the remote
extended features (known as remote host features) before signalling
this link as connected.

This change introduces full reference counting of incoming and outgoing
ACL links and the Bluetooth core will disconnect both if no owner of it
is present. To better handle interoperability during the pairing phase
the disconnect timeout for incoming connections has been increased to
10 seconds. This is five times more than for outgoing connections.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Simple Pairing process can only be used if both sides have the
support enabled in the host stack. The current Bluetooth specification
has three ways to detect this support.

If an Extended Inquiry Result has been sent during inquiry then it
is safe to assume that Simple Pairing is enabled. It is not allowed
to enable Extended Inquiry without Simple Pairing. During the remote
name request phase a notification with the remote host supported
features will be sent to indicate Simple Pairing support. Also the
second page of the remote extended features can indicate support for
Simple Pairing.

For all three cases the value of remote Simple Pairing mode is stored
in the inquiry cache for later use.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Simple Pairing feature is optional and needs to be enabled by the
host stack first. The Linux kernel relies on the Bluetooth daemon to
either enable or disable it, but at any time it needs to know the
current state of the Simple Pairing mode. So track any changes made
by external entities and store the current mode in the HCI device
structure.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

During the Simple Pairing process the HCI disconnect timer must be
disabled. The way to do this is by holding a reference count of the
HCI connection. The Simple Pairing process on both sides starts with
an IO Capabilities Request and ends with Simple Pairing Complete.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth specification supports the default link policy settings
on a per host controller basis. For every new connection the link
manager would then use these settings. It is better to use this instead
of bothering the controller on every connection setup to overwrite the
default settings.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The connection packet type can be changed after the connection has been
established and thus needs to be properly tracked to ensure that the
host stack has always correct and valid information about it.

On incoming connections the Bluetooth core switches the supported packet
types to the configured list for this controller. However the usefulness
of this feature has been questioned a lot. The general consent is that
every Bluetooth host stack should enable as many packet types as the
hardware actually supports and leave the decision to the link manager
software running on the Bluetooth chip.

When running on Bluetooth 2.0 or later hardware, don't change the packet
type for incoming connections anymore. This hardware likely supports
Enhanced Data Rate and thus leave it completely up to the link manager
to pick the best packet type.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth HCI commands are divided into logical OGF groups for
easier identification of their purposes. While this still makes sense
for the written specification, its makes the code only more complex
and harder to read. So instead of using separate OGF and OCF values
to identify the commands, use a common 16-bit opcode that combines
both values. As a side effect this also reduces the complexity of
OGF and OCF calculations during command header parsing.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

To better support and handle eSCO links in the future a bunch of
constants needs to be added and some basic routines need to be
updated. This is the initial step.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For consistency with other skb data accessors, reducing the number of direct
accesses to skb->data.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In case of non-blocking connects it is possible that the last user
of an ACL link quits before the connection has been fully established.
This will lead to a race condition where the internal state of a
connection is closed, but the actual link has been established and is
active. In case of Bluetooth 1.2 and later devices it is possible to
call create connection cancel to abort the connect. For older devices
the disconnect timer will be used to trigger the needed disconnect.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The command complete event of the exit periodic inquiry command must
clear the HCI_INQUIRY flag and finish the HCI request.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch assigns the next free HCI device identifier to Bluetooth
devices based on the SDIO interface.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch introduces the automatic sniff mode feature. This allows
the host to switch idle connections into sniff mode to safe power.
Signed-off-by: NUlisses Furquim <ulissesf@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch introduces a quirk that allows the drivers to tell the host
to correct the SCO buffer size values.
Signed-off-by: NOlivier Galibert <galibert@pobox.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds the endian annotations to the Bluetooth core.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the handling of the extended inquiry responses and
inserts them into the inquiry cache.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The HCI page scan repetition mode change event contains the actual
page scan repetition mode for the remote device. It is the same
value that is received from an inquiry response and it can be used
to make further reconnections faster.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements a workaround for buggy Bluetooth 1.2 devices from
Silicon Wave. Their inquiry results with RSSI contain the page scan mode
field. This field was removed in the final Bluetooth 1.2 specification.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!