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>

Now that there are no more users of the l2cap_conn_shutdown API (since
smp.c switched to using hci_disconnect) we can simply remove it along
with all of it's l2cap_conn variables.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Relying on the l2cap_conn_del procedure (triggered through the
l2cap_conn_shutdown API) to get the connection disconnected is not
reliable as it depends on all users releasing (through hci_conn_drop)
and that there's at least one user (so hci_conn_drop is called at least
one time).

A much simpler and more reliable solution is to call hci_disconnect()
directly from the SMP code when we want to disconnect. One side-effect
this has is that it prevents any SMP Failure PDU from being sent before
the disconnection, however neither one of the scenarios where
l2cap_conn_shutdown was used really requires this.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When the l2cap_conn_del() function is used we do not want to wait around
"in case something happens" before disconnecting. This patch sets the
disconnection timeout to 0 so that the disconnection routines get
immediately scheduled.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We can't have hci_chan contribute to the "active" reference counting of
the hci_conn since otherwise the connection would never get dropped when
there are no more users (since hci_chan would be counted as a user).
This patch removes hold() when creating the hci_chan and drop() when
destroying it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When hci_chan_del is called the disconnection routines get scheduled
through a workqueue. If there's any incoming ACL data before the
routines get executed there's a chance that a new hci_chan is created
and the disconnection never happens. This patch adds a new hci_conn flag
to indicate that we're in the process of driving the connection down. We
set the flag in hci_chan_del and check for it in hci_chan_create so that
no new channels are created for the same connection.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The hci_chan_del() function is used in scenarios where we've decided we
want to get rid of the underlying baseband link. It makes therefore
sense to force the disc_timeout to 0 so that the disconnection routines
are immediately scheduled.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The hci_chan_del() function was doing a hci_conn_drop() but there was no
matching hci_conn_hold() in the hci_chan_create() function. Furthermore,
as the hci_chan struct holds a pointer to the hci_conn there should be
proper use of hci_conn_get/put. This patch fixes both issues so that
hci_chan does correct reference counting of the hci_conn object.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

There's no point in passing a "small" timeout to queue_delayed_work() to
try to get the callback faster scheduled. Passing 0 is perfectly valid
and will cause a shortcut to a direct queue_work().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The necessary steps for freeing connection paramaters have grown quite a
bit so we can simplify the code by factoring it out into its own
function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Wherever we keep hci_conn pointers around we should be using
hci_conn_get/put to ensure that they stay valid. This patch fixes
all places violating against the principle currently.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

It's natural to have *_get() functions that increment the reference
count of an object to return the object type itself. This way it's
simple to make a copy of the object pointer and increase the reference
count in a single step. This patch updates two such get() functions,
namely hci_conn_get() and l2cap_conn_get(), and updates the users to
take advantage of the new API.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we get an LE connection complete event there's really no reason to
look through the entire connection parameter list as the entry should be
present in the hdev->pend_le_conns list too. This patch changes the
lookup code to do a more restricted lookup only in the pend_le_conns
list.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

In the hci_le_conn_complete_evt() function there's no need to set the
addr_type value until it's actually needed, i.e. for the black list
lookup. This patch moves the code a bit further down in the function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Now that SMP has been converted to use fixed channels we've got a bit of
a problem with the hci_conn reference counting. So far the L2CAP code
has kept a reference for each L2CAP channel that was notified of the
connection. With SMP however this would mean that the connection is
never dropped even though there are no other users of it. Furthermore,
SMP already does its own hci_conn reference counting internally,
starting from a security or pairing request and ending with the key
distribution.

This patch makes L2CAP fixed channels default to the L2CAP core not
keeping a hci_conn reference for them. A new FLAG_HOLD_HCI_CONN flag is
added so that L2CAP users can declare an exception to this rule and hold
a reference even for their fixed channels. One such exception is the
L2CAP socket layer which does want a reference for each socket (e.g. an
ATT socket which uses a fixed channel).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The l2cap_chan_add() function doesn't require the channel to be
unlocked. It only requires the l2cap_conn to be unlocked. Therefore,
it's unnecessary to unlock a channel before calling l2cap_chan_add().
This patch removes such unnecessary unlocking from the
l2cap_chan_connect() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The l2cap_create_le_flowctl_pdu() function that l2cap_segment_le_sdu()
calls is perfectly capable of doing packet fragmentation if given bigger
PDUs than the HCI buffers allow. Forcing the PDU length based on the HCI
MTU (conn->mtu) would therefore needlessly strict operation on hardware
with limited LE buffers (e.g. both Intel and Broadcom seem to have this
set to just 27 bytes).

This patch removes the restriction and makes it possible to send PDUs of
the full length that the remote MPS value allows.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

Signed-off-by: Jade Bilkey <herself@thefumon.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

There is an ongoing work on cleaning MIPS's nvram support so it could be
re-used on other platforms (bcm53xx to say precisely).
This will require a bit of extra logic in bcma this patch implements.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Merge tag 'mac80211-next-for-john-2014-08-29' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg <johannes@sipsolutions.net> says:

"Not that much content this time. Some RCU cleanups, crypto
performance improvements, and various patches all over,
rather than listing them one might as well look into the
git log instead."
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Conflicts:
	drivers/net/wireless/ath/wil6210/wmi.c

Merge tag 'mac80211-for-john-2014-08-29' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg <johannes@sipsolutions.net> says:

"Here are a few fixes for mac80211. One has been discussed for a while
and adds a terminating NUL-byte to the alpha2 sent to userspace, which
shouldn't be necessary but since many places treat it as a string we
couldn't move to just sending two bytes.

In addition to that, we have two VLAN fixes from Felix, a mesh fix, a
fix for the recently introduced RX aggregation offload, a revert for
a broken patch (that luckily didn't really cause any harm) and a small
fix for alignment in debugfs."
Signed-off-by: John W. Linville <linville@redhat.com>

The auxiliary station is being handled using the internal
station helper functions, clean that up and make the helpers
static.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

Unify all the functions that handle the per-interface broadcast
station and make them have mvm and vif parameters. While at it,
add a new function to allocate the broadcast station instead of
open-coding it, and make the combined alloc+send and free+send
functions use the alloc/free & send functions.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>