The new connection parameters now match the recommended values for
Proximity and Health Thermometer profiles. The previous values were
ramdomly chosen, and are either too low or too high for most cases.
New values:
Scan Interval: 60 ms
Scan Window: 30 ms
Minimum Connection Interval: 50 ms
Maximum Connection Interval: 70 ms
Supervision Timeout: 420 ms
See "Table 5.2: Recommended Scan Interval and Scan Window Values" and
"Table 5.3: Recommended Connection Interval Values" for both profiles
for details. Note that the "fast connection" parameters were chosen,
because we do not support yet dynamically changing these parameters from
initiator side.
Additionally, the Proximity profile recommends (section "4.4 Alert on
Link Loss"):
"It is recommended that the Link Supervision Timeout (LSTO) is set to 6x
the connection interval."
Minimum_CE_Length and Maximum_CE_Length were also changed from 0x0001 to
0x0000 because they are informational and optional, and old value was
not reflecting reality.
Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
This patch fixes wrong memcpy size when copying rand value to
HCI_OP_LE_START_ENC command.
The compiler pretends that the array parameter was declared as a pointer
and sizeof reports the size of the pointer. [1]
[1] http://www.c-faq.com/aryptr/aryparmsize.html
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
If the remote device is not present, the connections attemp fails and
the struct hci_conn was not freed
Signed-off-by: Tomas Targownik <ttargownik@geicp.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
In hci_conn_security ( which is used during L2CAP connection
establishment ) test for HCI_CONN_ENCRYPT_PEND state also
sets this state, which is bogus and leads to connection time-out
on L2CAP sockets in certain situations (especially when
using non-ssp devices )
Signed-off-by: Ilia Kolomisnky <iliak@ti.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
As the default security level (BT_SECURITY_SDP) doesn't make sense for
LE links, initialize LE links with something that makes sense.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
This adds support for starting SMP Phase 2 Encryption, when the initial
SMP negotiation is successful. This adds the LE Start Encryption and LE
Long Term Key Request commands and related events.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
With older userspace versions (using hciops) it might not have the
key type to check if the key has sufficient security for any security
level so it is necessary to check the return of hci_conn_auth to make
sure the connection is authenticated
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
If the link key is secure (authenticated or combination 16 digit)
the sec_level will be always BT_SECURITY_HIGH. Therefore, instead
of checking the link key type simply check the sec_level on the link.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Add BT_POWER socket option used to control the power
characteristics of the underlying ACL link. When the remote end
has put the link in sniff mode and the host stack wants to send
data we need need to explicitly exit sniff mode to work well with
certain devices (For example, A2DP on Plantronics Voyager 855).
However, this causes problems with HID devices.
Hence, moving into active mode when sending data, irrespective
of who set the sniff mode has been made as a socket option. By
default, we will move into active mode. HID devices can set the
L2CAP socket option to prevent this from happening.
Currently, this has been implemented for L2CAP sockets. This has been
tested with incoming and outgoing L2CAP sockets for HID and A2DP.
Based on discussions on linux-bluetooth and patches submitted by
Andrei Emeltchenko.
Signed-off-by: Jaikumar Ganesh <jaikumar@google.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Set the 'peer_addr_type' field of the LE Create Connection command
sent in hci_le_connect().
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Acked-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
When connecting to a LE device, we need to check the advertising
cache in order to know the address type of that device.
If its advertising entry is not found, the connection is not
established and hci_connect() returns error.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Acked-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
There is no need to check the connection's state since hci_conn_add()
has just created a new connection and its state has been set properly.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Acked-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Legacy devices don't re-authenticate the link properly if a link key
already exists. Thus, don't update sec_level for this case even if
hci_auth_complete_evt indicates success. Otherwise the sec_level will
not reflect a real security on the link.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
In case of pre v2.1 devices authentication request will return
success immediately if the link key already exists without any
authentication process.
That means, it's not possible to re-authenticate the link if you
already have combination key and for instance want to re-authenticate
to get the high security (use 16 digit pin).
Therefore, it's necessary to check security requirements on auth
complete event to prevent not enough secure connection.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Some test systems require an arbitrary delay to the auto-accept test
cases for Secure Simple Pairing in order for the tests to pass.
Previously when this was handled in user space it was worked around by
code modifications and recompilation, but now that it's on the kernel
side it's more convenient if there's a debugfs interface for it.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Keep the link key type together with connection and use it to
map security level to link key requirements. Authenticate and/or
encrypt connection if the link is insufficiently secure.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Use ERR_PTR mechanism to return error from hci_connect.
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
This patch prevents a crash when remote host tries to create a LE
link which already exists. i.e.: call l2test twice passing the
same parameters.
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
The remote authentication requirements for conections need to be
initialized to 0xff (unknown) since it is possible that we receive a IO
Capability Request before we have received information about the remote
requirements.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
If the new connection update parameter are accepted, the LE master
host sends the LE Connection Update Command to its controller informing
the new requested parameters.
Signed-off-by: Claudio Takahasi <claudio.takahasi@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Fix LE connections not being marked as master.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth chips may have separate buffers for LE traffic.
This patch add support to use LE buffers provided by the chip.
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth V4.0 adds support for Low Energy (LE) connections.
Specification introduces new set of hci commands to control LE
connection. This patch adds logic to create, cancel and disconnect
LE connections.
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
This patch adds a new set_io_capability management command which is used
to set the IO capability for Secure Simple Pairing (SSP) as well as the
Security Manager Protocol (SMP). The value is per hci_dev and each
hci_conn object inherits it upon creation.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
The conn->sec_level value is supposed to represent the current level of
security that the connection has. However, by assigning to it before
requesting authentication it will have the wrong value during the
authentication procedure. To fix this a pending_sec_level variable is
added which is used to track the desired security level while making
sure that sec_level always represents the current level of security.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
If an existing connection has a MITM protection requirement (the first
bit of the auth_type) then that requirement should not be cleared by new
sockets that reuse the ACL but don't have that requirement.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
This reverts commit 045309820a. That
commit is wrong for two reasons:
- The conn->sec_level shouldn't be updated without performing
authentication first (as it's supposed to represent the level of
security that the existing connection has)
- A higher auth_type value doesn't mean "more secure" like the commit
seems to assume. E.g. dedicated bonding with MITM protection is 0x03
whereas general bonding without MITM protection is 0x04. hci_conn_auth
already takes care of updating conn->auth_type so hci_connect doesn't
need to do it.
Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Do not use assignment in IF condition, remove extra spaces,
fixing typos, simplify code.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Qualcomm, Inc. has reassigned rights to Code Aurora Forum. Accordingly,
as files are modified by Code Aurora Forum members, the copyright
statement will be updated.
Signed-off-by: Ron Shaffer <rshaffer@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Update auth level for already existing connections if it is lower
than required by new connection.
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Reviewed-by: Emeltchenko Andrei <andrei.emeltchenko@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When in sniff mode with a long interval time (1.28s) it can take 4+ seconds
to establish a SCO link. Fix by requesting active mode before requesting
SCO connection. This improves SCO setup time to ~500ms.
Bluetooth headsets that use a long interval time, and exhibit the long
SCO connection time include Motorola H790, HX1 and H17. They have a
CSR 2.1 chipset.
Verified this behavior and fix with host Bluetooth chipsets: BCM4329 and
TI1271.
2009-10-13 14:17:46.183722 > HCI Event: Mode Change (0x14) plen 6
status 0x00 handle 1 mode 0x02 interval 2048
Mode: Sniff
2009-10-13 14:17:53.436285 < HCI Command: Setup Synchronous Connection (0x01|0x0028) plen 17
handle 1 voice setting 0x0060
2009-10-13 14:17:53.445593 > HCI Event: Command Status (0x0f) plen 4
Setup Synchronous Connection (0x01|0x0028) status 0x00 ncmd 1
2009-10-13 14:17:57.788855 > HCI Event: Synchronous Connect Complete 0x2c) plen 17
status 0x00 handle 257 bdaddr 00:1A:0E:F1:A4:7F type eSCO
Air mode: CVSD
Signed-off-by: Nick Pelly <npelly@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes double pairing issues with Secure Simple
Paring support. It was observed that when pairing with SSP
enabled, that the confirmation will be asked twice.
http://www.spinics.net/lists/linux-bluetooth/msg02473.html
This also causes bug when initiating SSP connection from
Windows Vista.
The reason is because bluetoothd does not store link keys
since HCIGETAUTHINFO returns 0. Setting default to general
bonding fixes these issues.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The device model itself has no real usable reference counting at the
moment and this causes problems if parents are deleted before their
children. The device model itself handles the memory details of this
correctly, but the uevent order is not consistent. This causes various
problems for systems like HAL or even X.
So until device_put() does a proper cleanup, the device for Bluetooth
connection will be protected with an extra reference counting to ensure
the correct order of uevents when connections are terminated.
This is not an automatic feature. Higher Bluetooth layers like HIDP or
BNEP should grab this new reference to ensure that their uevents are
send before the ones from the parent device.
Based on a report by Brian Rogers <brian@xyzw.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The connection setup phase takes around 2 seconds or longer and in
that time it is possible that the need for an ACL connection is no
longer present. If that happens then, the connection attempt will
be canceled.
This only applies to outgoing connections, but currently it can also
be triggered by incoming connection. Don't call hci_acl_connect_cancel()
on incoming connection since these have to be either accepted or rejected
in this state. Once they are successfully connected they need to be
fully disconnected anyway.
Also remove the wrong hci_acl_disconn() call for SCO and eSCO links
since at this stage they can't be disconnected either, because the
connection handle is still unknown.
Based on a report by Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Johan Hedberg <johan.hedberg@nokia.com>
The module refcount is increased by hci_dev_hold() call in hci_conn_add()
and decreased by hci_dev_put() call in del_conn(). In case the connection
setup fails, hci_dev_put() is never called.
Procedure to reproduce the issue:
# hciconfig hci0 up
# lsmod | grep btusb -> "used by" refcount = 1
# hcitool cc <non-exisiting bdaddr> -> will get timeout
# lsmod | grep btusb -> "used by" refcount = 2
# hciconfig hci0 down
# lsmod | grep btusb -> "used by" refcount = 1
# rmmod btusb -> ERROR: Module btusb is in use
The hci_dev_put() call got moved into del_conn() with the 2.6.25 kernel
to fix an issue with hci_dev going away before hci_conn. However that
change was wrong and introduced this problem.
When calling hci_conn_del() it has to call hci_dev_put() after freeing
the connection details. This handling should be fully symmetric. The
execution of del_conn() is done in a work queue and needs it own calls
to hci_dev_hold() and hci_dev_put() to ensure that the hci_dev stays
until the connection cleanup has been finished.
Based on a report by Bing Zhao <bzhao@marvell.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Bing Zhao <bzhao@marvell.com>
Due to a semantic changes in flush_workqueue() the current approach of
synchronizing the sysfs handling for connections doesn't work anymore. The
whole approach is actually fully broken and based on assumptions that are
no longer valid.
With the introduction of Simple Pairing support, the creation of low-level
ACL links got changed. This change invalidates the reason why in the past
two independent work queues have been used for adding/removing sysfs
devices. The adding of the actual sysfs device is now postponed until the
host controller successfully assigns an unique handle to that link. So
the real synchronization happens inside the controller and not the host.
The only left-over problem is that some internals of the sysfs device
handling are not initialized ahead of time. This leaves potential access
to invalid data and can cause various NULL pointer dereferences. To fix
this a new function makes sure that all sysfs details are initialized
when an connection attempt is made. The actual sysfs device is only
registered when the connection has been successfully established. To
avoid a race condition with the registration, the check if a device is
registered has been moved into the removal work.
As an extra protection two flush_work() calls are left in place to
make sure a previous add/del work has been completed first.
Based on a report by Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Justin P. Mattock <justinmattock@gmail.com>
Tested-by: Roger Quadros <ext-roger.quadros@nokia.com>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
The Bluetooth 2.1 specification introduced four different security modes
that can be mapped using Legacy Pairing and Simple Pairing. With the
usage of Simple Pairing it is required that all connections (except
the ones for SDP) are encrypted. So even the low security requirement
mandates an encrypted connection when using Simple Pairing. When using
Legacy Pairing (for Bluetooth 2.0 devices and older) this is not required
since it causes interoperability issues.
To support this properly the low security requirement translates into
different host controller transactions depending if Simple Pairing is
supported or not. However in case of Simple Pairing the command to
switch on encryption after a successful authentication is not triggered
for the low security mode. This patch fixes this and actually makes
the logic to differentiate between Simple Pairing and Legacy Pairing
a lot simpler.
Based on a report by Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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: Marcel Holtmann <marcel@holtmann.org>
The authentication requirement got only updated when the security level
increased. This is a wrong behavior. The authentication requirement is
read by the Bluetooth daemon to make proper decisions when handling the
IO capabilities exchange. So set the value that is currently expected by
the higher layers like L2CAP and RFCOMM.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Some of the qualification tests demand that in case of failures in L2CAP
the HCI disconnect should indicate a reason why L2CAP fails. This is a
bluntly layer violation since multiple L2CAP connections could be using
the same ACL and thus forcing a disconnect reason is not a good idea.
To comply with the Bluetooth test specification, the disconnect reason
is now stored in the L2CAP connection structure and every time a new
L2CAP channel is added it will set back to its default. So only in the
case where the L2CAP channel with the disconnect reason is really the
last one, it will propagated to the HCI layer.
The HCI layer has been extended with a disconnect indication that allows
it to ask upper layers for a disconnect reason. The upper layer must not
support this callback and in that case it will nicely default to the
existing behavior. If an upper layer like L2CAP can provide a disconnect
reason that one will be used to disconnect the ACL or SCO link.
No modification to the ACL disconnect timeout have been made. So in case
of Linux to Linux connection the initiator will disconnect the ACL link
before the acceptor side can signal the specific disconnect reason. That
is perfectly fine since Linux doesn't make use of this value anyway. The
L2CAP layer has a perfect valid error code for rejecting connection due
to a security violation. It is unclear why the Bluetooth specification
insists on having specific HCI disconnect reason.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When no authentication requirements are selected, but an outgoing or
incoming connection has requested any kind of security enforcement,
then set these authentication requirements.
This ensures that the userspace always gets informed about the
authentication requirements (if available). Only when no security
enforcement has happened, the kernel will signal invalid requirements.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When receiving incoming connection to specific services, always use
general bonding. This ensures that the link key gets stored and can be
used for further authentications.
Signed-off-by: Marcel 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: Marcel Holtmann <marcel@holtmann.org>
The current security model is based around the flags AUTH, ENCRYPT and
SECURE. Starting with support for the Bluetooth 2.1 specification this is
no longer sufficient. The different security levels are now defined as
SDP, LOW, MEDIUM and SECURE.
Previously it was possible to set each security independently, but this
actually doesn't make a lot of sense. For Bluetooth the encryption depends
on a previous successful authentication. Also you can only update your
existing link key if you successfully created at least one before. And of
course the update of link keys without having proper encryption in place
is a security issue.
The new security levels from the Bluetooth 2.1 specification are now
used internally. All old settings are mapped to the new values and this
way it ensures that old applications still work. The only limitation
is that it is no longer possible to set authentication without also
enabling encryption. No application should have done this anyway since
this is actually a security issue. Without encryption the integrity of
the authentication can't be guaranteed.
As default for a new L2CAP or RFCOMM connection, the LOW security level
is used. The only exception here are the service discovery sessions on
PSM 1 where SDP level is used. To have similar security strength as with
a Bluetooth 2.0 and before combination key, the MEDIUM level should be
used. This is according to the Bluetooth specification. The MEDIUM level
will not require any kind of man-in-the-middle (MITM) protection. Only
the HIGH security level will require this.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
With the introduction of CONFIG_DYNAMIC_PRINTK_DEBUG it is possible to
allow debugging without having to recompile the kernel. This patch turns
all BT_DBG() calls into pr_debug() to support dynamic debug messages.
As a side effect all CONFIG_BT_*_DEBUG statements are now removed and
some broken debug entries have been fixed.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Security Mode 4 of the Bluetooth 2.1 specification has strict
authentication and encryption requirements. It is the initiators job
to create a secure ACL link. However in case of malicious devices, the
acceptor has to make sure that the ACL is encrypted before allowing
any kind of L2CAP connection. The only exception here is the PSM 1 for
the service discovery protocol, because that is allowed to run on an
insecure ACL link.
Previously it was enough to reject a L2CAP connection during the
connection setup phase, but with Bluetooth 2.1 it is forbidden to
do any L2CAP protocol exchange on an insecure link (except SDP).
The new hci_conn_check_link_mode() function can be used to check the
integrity of an ACL link. This functions also takes care of the cases
where Security Mode 4 is disabled or one of the devices is based on
an older specification.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
