We can only determine the final security level when both pairing request
and response have been exchanged. When initiating pairing the starting
target security level is set to MEDIUM unless explicitly specified to be
HIGH, so that we can still perform pairing even if the remote doesn't
have MITM capabilities. However, once we've received the pairing
response we should re-consult the remote and local IO capabilities and
upgrade the target security level if necessary.

Without this patch the resulting Long Term Key will occasionally be
reported to be unauthenticated when it in reality is an authenticated
one.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

The hci_recv_fragment function is no longer used by any driver and thus
do not export it. In fact it is not even needed by the core and it can
be removed altogether.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When receiving USB interrupt, bulk or isochronous packet, they normally
come in fragments. So far the driver just handed each fragment off to
the hci_recv_fragment function of the Bluetooth core. That function is
however so specific that is does not belong in the core. This patch
implements the same reassembly logic in the driver.

In addition this fixes a long standing bug where multiple complete
packets are received within a single USB packet.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The actual packet reassembly should be done inside the driver. To allow
this to happen cleanly in future patches, split the fragment reception
into its own functions.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The btusb driver has been around for a while now and it is time to
bring its coding style in sync with what has been done for the
Bluetooth subsystem and other drivers.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Add Jukka to 6LoWPAN maintainer list. He will concentrate on
generic and bluetooth part of 6LoWPAN stack.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The Bluetooth core already does processing of the HCI command header
and puts it together before sending it to the driver. It is not really
efficient for the driver to look at the HCI command header again in
case it has to make certain decisions about certain commands. To make
this easier, just provide the opcode as part of the SKB control buffer
information. The extra information about the opcode is optional and
only provided for HCI commands.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The struct bt_skb_cb size needs to stay within the limits of skb->cb
at all times and to ensure that add a BUILD_BUG_ON to check for it at
compile time.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The complete TX URB handling is done via a switch statement in the
btusb_send_frame function. To allow for more clear separation between
control, bulk and isoc URBs, split them into allocation and submission.

Previously the inc_tx function has been used for tracking in-flight
URB for HCI commands and ACL data packets. Convert that into a common
function that either submits the URB or queues it when needed.

This provides the flexibility to allow vendor specific hdev->send_frame
callbacks without having to duplicate the whole URB handling logic.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

All hdev->send() calls are these days done through a work queue. For the
btusb driver this means the btusb_send_frame() function. Because of this
we can safely use GFP_KERNEL for all memory allocations in this code
path.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The hci_update_random_address will clear the RPA_EXPIRED flag and
proceed with setting a new one if the flag was set. However, the
set_random_addr() function that is called may choose to defer the update
to a later moment. In such a case the flag would incorrectly remain
unset unless set_random_addr() re-sets it. This patch fixes the issue.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If encryption fails and we're using an RPA it may be because of a
conflict with another device. To avoid repeated failures the safest
action is to simply mark the RPA as expired so that a new one gets
generated as soon as the connection drops.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This is a trivial change to use a proper define for the NoInputNoOutput
IO capability instead of hard-coded values.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Even if we have no connection-oriented channels we should perform the
L2CAP Information Request procedures before notifying L2CAP channels of
the connection. This is so that the L2CAP channel implementations can
perform checks on what the remote side supports (e.g. does it support
the fixed channel in question).

So far the code has relied on the l2cap_do_start() function to initiate
the Information Request, however l2cap_do_start() is used on a
per-channel basis and only for connection-oriented channels. This means
that if there are no connection-oriented channels on the system we would
never start the Information Request procedure.

This patch creates a new l2cap_request_info() helper function to
initiate the Information Request procedure, and ensures that it is
called whenever a BR/EDR connection has been established. The patch also
updates fixed channels to be notified of connection readiness only once
the Information Request procedure has completed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

There are several places that need to determine the security level that
an LTK can provide. This patch adds a convenience function for this to
help make the code more readable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When the local IO capability is NoInputNoOutput any attempt to convert
the remote authentication requirement to a target security level is
futile. This patch makes sure that we set the target security level at
most to MEDIUM if the local IO capability is NoInputNoOutput.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

All the cases where we mark SMP commands as dissalowed are their
respective command handlers. We can therefore simplify the code by
always clearing the bit immediately after testing it. This patch
converts the corresponding test_bit() call to a test_and_clear_bit()
call and also removes the now unused SMP_DISALLOW_CMD macro.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The SMP specification states that we should ignore any unknown bits from
the authentication requirement. We already have a define for masking out
unknown bits but we haven't used it in all places so far. This patch
adds usage of the AUTH_REQ_MASK to all places that need it and ensures
that we don't pass unknown bits onward to other functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We do nothing else with the auth variable in smp_cmd_pairing_rsp()
besides passing it to tk_request() which in turn only cares about
whether one of the sides had the MITM bit set. It is therefore
unnecessary to assign a value to it until just before calling
tk_request(), and this value can simply be the bit-wise or of the local
and remote requirements.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If the remote side is not distributing its IRK but is distributing the
CSRK the next PDU after master identification is the Signing
Information. This patch fixes a missing SMP_ALLOW_CMD() for this in the
smp_cmd_master_ident() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Packets that are supposed to be delivered via the peer device need to
be checked and sent to correct device. This requires that user has set
the routes properly so that the 6lowpan module can then figure out
the destination gateway and the correct Bluetooth device.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 3.17.x

The peer IPv6 address contained wrong U/L bit in the EUI-64 part.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 3.17.x

Use the default connection timeout value defined in l2cap.h because
the current timeout was too short and most of the time the connection
attempts timed out.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 3.17.x

Suspend could fail for some platforms because
btusb_suspend==> btusb_stop_traffic ==> usb_kill_anchored_urbs.

When btusb_bulk_complete returns before system suspend and resubmits
an URB, the system cannot enter suspend state.
Signed-off-by: Champion Chen <champion_chen@realsil.com.cn>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

Whether through HCI with BR/EDR or SMP with LE when authentication fails
we should also notify any pending Pair Device mgmt command. This patch
updates the mgmt_auth_failed function to take the actual hci_conn object
and makes sure that any pending pairing command is notified and cleaned
up appropriately.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch fixes the following type of static analyzer warning (and
probably a real bug as well as the NULL check should be there for a
reason):

net/bluetooth/smp.c:1182 smp_conn_security() warn: variable dereferenced before check 'conn' (see line 1174)
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using an char array.

The new code can be compiled with both gcc and clang.

struct shash_desc contains a flexible array member member ctx declared with
CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
of the array declared after struct shash_desc with long long.

No trailing padding is required because it is not a struct type that can
be used in an array.

The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
as would be the case for a struct containing a member with
CRYPTO_MINALIGN_ATTR.
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

SMP defines quite clearly when certain PDUs are to be expected/allowed
and when not, but doesn't have any explicit request/response definition.
So far the code has relied on each PDU handler to behave correctly if
receiving PDUs at an unexpected moment, however this requires many
different checks and is prone to errors.

This patch introduces a generic way to keep track of allowed PDUs and
thereby reduces the responsibility & load on individual command
handlers. The tracking is implemented using a simple bit-mask where each
opcode maps to its own bit. If the bit is set the corresponding PDU is
allow and if the bit is not set the PDU is not allowed.

As a simple example, when we send the Pairing Request we'd set the bit
for Pairing Response, and when we receive the Pairing Response we'd
clear the bit for Pairing Response.

Since the disallowed PDU rejection is now done in a single central place
we need to be a bit careful of which action makes most sense to all
cases. Previously some, such as Security Request, have been simply
ignored whereas others have caused an explicit disconnect.

The only PDU rejection action that keeps good interoperability and can
be used for all the applicable use cases is to drop the data. This may
raise some concerns of us now being more lenient for misbehaving (and
potentially malicious) devices, but the policy of simply dropping data
has been a successful one for many years e.g. in L2CAP (where this is
the *only* policy for such cases - we never request disconnection in
l2cap_core.c because of bad data). Furthermore, we cannot prevent
connected devices from creating the SMP context (through a Security or
Pairing Request), and once the context exists looking up the
corresponding bit for the received opcode and deciding to reject it is
essentially an equally lightweight operation as the kind of rejection
that l2cap_core.c already successfully does.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we're in the process of receiving keys in phase 3 of SMP we keep
track of which keys are still expected in the smp->remote_key_dist
variable. If we still have some key bits set we need to continue waiting
for more PDUs and not needlessly call smp_distribute_keys(). This patch
fixes two such cases in the smp_cmd_master_ident() and
smp_cmd_ident_addr_info() handler functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a define for the allowed bits of the key distribution
mask so we don't have to have magic 0x07 constants throughout the code.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Before the move the l2cap_chan the SMP context (smp_chan) didn't have
any kind of proper locking. The best there existed was the
HCI_CONN_LE_SMP_PEND flag which was used to enable mutual exclusion for
potential multiple creators of the SMP context.

Now that SMP has been converted to use the l2cap_chan infrastructure and
since the SMP context is directly mapped to a corresponding l2cap_chan
we get the SMP context locking essentially for free through the
l2cap_chan lock. For all callbacks that l2cap_core.c makes for each
channel implementation (smp.c in the case of SMP) the l2cap_chan lock is
held through l2cap_chan_lock(chan).

Since the calls from l2cap_core.c to smp.c are covered the only missing
piece to have the locking implemented properly is to ensure that the
lock is held for any other call path that may access the SMP context.
This means user responses through mgmt.c, requests to elevate the
security of a connection through hci_conn.c, as well as any deferred
work through workqueues.

This patch adds the necessary locking to all these other code paths that
try to access the SMP context. Since mutual exclusion for the l2cap_chan
access is now covered from all directions the patch also removes
unnecessary HCI_CONN_LE_SMP_PEND flag (once we've acquired the chan lock
we can simply check whether chan->smp is set to know if there's an SMP
context).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Now that the identity address update happens through its own deferred
work there's no need to have smp_distribute_keys anymore behind a second
deferred work. This patch removes this extra construction and makes the
code do direct calls to smp_distribute_keys() again.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The identity address update of all channels for an l2cap_conn needs to
take the lock for each channel, i.e. it's safest to do this by a
separate workqueue callback.

Previously this was partially solved by moving the entire SMP key
distribution behind a workqueue. However, if we want SMP context locking
to be correct and safe we should always use the l2cap_chan lock when
accessing it, meaning even smp_distribute_keys needs to take that lock
which would once again create a dead lock when updating the identity
address.

The simplest way to solve this is to have l2cap_conn manage the deferred
work which is what this patch does. A subsequent patch will remove the
now unnecessary SMP key distribution work struct.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When smp_resume_cb is called if we're not encrypted (i.e. the callback
wasn't called because the connection became encrypted) we shouldn't take
any action at all. This patch moves also the security_timer cancellation
behind this condition.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The SMP security timer used to be able to modify the SMP context state
but now days it simply calls hci_disconnect(). It is therefore
unnecessary to have extra sanity checks for the SMP context after
canceling the timer.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The "pending" L2CAP response value is not defined for LE CoC. This patch
adds a clarifying comment to the code so that the reader will not think
there is a bug in trying to use this value for LE CoC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

To give all hci_disconnect() users the advantage of getting the clock
offset read automatically this patch moves the necessary code from
hci_conn_timeout() into hci_disconnect(). This way we pretty much always
update the clock offset when disconnecting.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

There's no reason to custom build the HCI_Disconnect command in the
Disconnect Device mgmt command handler. This patch updates the code to
use hci_disconnect() instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We'll soon use hci_disconnect() from places that are interested to know
whether the hci_send_cmd() really succeeded or not. This patch updates
hci_disconnect() to pass on any error returned from hci_send_cmd().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Returning failure from the SMP data parsing function will cause an
immediate disconnect, making any attempts to send a response PDU futile.
This patch updates the function to always either send a response or
return an error, but never both at the same time:

* In the case that HCI_LE_ENABLED is not set we want to send a Pairing Not
  Supported response but it is not required to force a disconnection, so
  do not set the error return in this case.

* If we get garbage SMP data we can just fail with the handler function
  instead of also trying to send an SMP Failure PDU.

* There's no reason to force a disconnection if we receive an unknown SMP
  command. Instead simply send a proper Command Not Supported SMP
  response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>