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no longer valid.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>
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: Marcel Holtmann <marcel@holtmann.org>
When attaching Bluetooth low-level connections to the bus, the bus name
is constructed from the remote address since at that time the connection
handle is not assigned yet. This has worked so far, but also caused a
lot of troubles. It is better to postpone the creation of the sysfs
entry to the time when the connection actually has been established
and then use its connection handle as unique identifier.
This also fixes the case where two different adapters try to connect
to the same remote device.
Signed-off-by: Marcel 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: Marcel 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: Marcel 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: Marcel 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: Marcel 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: Marcel Holtmann <marcel@holtmann.org>
Move hci_dev_put to del_conn to avoid hci dev going away before hci conn.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many-many code in the kernel initialized the timer->function
and timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.
The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because of workqueue delay, the put_device could be called before
device_del, so move it to del_conn.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the Bluetooth 1.2 specification the Extended SCO feature for
better audio connections was introduced. So far the Bluetooth core
wasn't able to handle any eSCO connections correctly. This patch
adds simple eSCO support while keeping backward compatibility with
older devices.
Signed-off-by: Marcel 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: Marcel 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: Marcel Holtmann <marcel@holtmann.org>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most Bluetooth chips don't support concurrent connect requests, because
this would involve a multiple baseband page with only one radio. In the
case an upper layer like L2CAP requests a concurrent connect these chips
return the error "Command Disallowed" for the second request. If this
happens it the responsibility of the Bluetooth core to queue the request
and try again after the previous connect attempt has been completed.
Signed-off-by: Marcel Holtmann <marcel@holtmann.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: Marcel Holtmann <marcel@holtmann.org>
This patch integrates the low-level connections (ACL and SCO) into the
driver model. Every connection is presented as device with the parent
set to its host controller device.
Signed-off-by: Marcel 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: Ulisses Furquim <ulissesf@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Get rid of needless casting of kmalloc() return value in net/
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A lot of places in there are including major.h for no reason whatsoever.
Removed. And yes, it still builds.
The history of that stuff is often amusing. E.g. for net/core/sock.c
the story looks so, as far as I've been able to reconstruct it: we used
to need major.h in net/socket.c circa 1.1.early. In 1.1.13 that need
had disappeared, along with register_chrdev(SOCKET_MAJOR, "socket",
&net_fops) in sock_init(). Include had not. When 1.2 -> 1.3 reorg of
net/* had moved a lot of stuff from net/socket.c to net/core/sock.c,
this crap had followed...
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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!
Marcel Holtmann