The discovery process has a timer for disabling scanning, however
scanning might be disabled through other means too like the auto-connect
process.  We should therefore ensure that the timer is never active
after sending a HCI command to disable scanning.

There was some existing code in stop_scan_complete trying to avoid the
timer when a connect request interrupts a discovery procedure, but the
other way around was not covered. This patch covers both scenarios by
canceling the timer as soon as we get a successful command complete for
the disabling HCI command.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Some devices may refuse to re-encrypt with the LTK if they haven't
received all our keys yet. This patch adds a 250ms delay before
attempting re-encryption with the LTK.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

It's not strictly speaking required to re-encrypt a link once we receive
an LTK since the connection is already encrypted with the STK. However,
re-encrypting with the LTK allows us to verify that we've received an
LTK that actually works.

This patch updates the SMP code to request encrypting with the LTK in
case we're in master role and waits until the key refresh complete event
before notifying user space of the distributed keys.

A new flag is also added for the SMP context to ensure that we
re-encryption only once in case of multiple calls to smp_distribute_keys.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

LE connection attempts do not have a controller side timeout in the same
way as BR/EDR has (in form of the page timeout). Since we always do
scanning before initiating connections the attempts are always expected
to succeed in some reasonable time.

This patch adds a timer which forces a cancellation of the connection
attempt within 20 seconds if it has not been successful by then. This
way we e.g. ensure that mgmt_pair_device times out eventually and gives
an error response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds defines for the initiator filter policy parameter values
of the HCI_LE_Create_Connection command. They will be used in a
subsequent patch to check whether we should have a timeout for the
connection attempt or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Now that we have nicely tracked values of the initiator and responder
address information we can pass that directly to the smp_c1 function
without worrying e.g. about who initiated the connection. This patch
updates the two places in smp.c to use the new variables.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

For SMP we need the local and remote addresses (and their types) that
were used to establish the connection. These may be different from the
Identity Addresses or even the current RPA. To guarantee that we have
this information available and it is correct track these values
separately from the very beginning of the connection.

For outgoing connections we set the values as soon as we get a
successful command status for HCI_LE_Create_Connection (for which the
patch adds a command status handler function) and for incoming
connections as soon as we get a LE Connection Complete HCI event.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We shouldn't update the hci_conn state to BT_CONNECT until the moment
that we're ready to send the initiating HCI command for it. If the
connection has the BT_CONNECT state too early the code responsible for
updating the local random address may incorrectly think there's a
pending connection in progress and refuse to update the address.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Different controllers behave differently when HCI_Set_Random_Address is
called while they are advertising or have a HCI_LE_Create_Connection in
progress. Some take the newly written address into use for the pending
operation while others use the random address that we had at the time
that the operation started.

Due to this undefined behavior and for the fact that we want to reliably
determine the initiator address of all connections for the sake of SMP
it's best to simply prevent the random address update if we have these
problematic operations in progress.

This patch adds a set_random_addr() helper function for the use of
hci_update_random_address which contains the necessary checks for
advertising and ongoing LE connections.

One extra thing we need to do is to clear the HCI_ADVERTISING flag in
the enable_advertising() function before sending any commands. Since
re-enabling advertising happens by calling first disable_advertising()
and then enable_advertising() all while having the HCI_ADVERTISING flag
set. Clearing the flag lets the set_random_addr() function know that
it's safe to write a new address at least as far as advertising is
concerned.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If SMP fails we should not leave any keys (LTKs or IRKs) hanging around
the internal lists. This patch adds the necessary code to
smp_chan_destroy to remove any keys we may have in case of pairing
failure.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The random numbers in Bluetooth Low Energy are 64-bit numbers and should
also be little endian since the HCI specification is little endian.

Change the whole Low Energy pairing to use __le64 instead of a byte
array.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

If some of the cleanup commands caused by mgmt_set_powered(off) never
complete we should still force the adapter to be powered down. This is
rather easy to do since hdev->power_off is already a delayed work
struct. This patch schedules this delayed work if at least one HCI
command was sent by the cleanup procedure.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When powering off and disconnecting devices we should also consider
connections which have not yet reached the BT_CONNECTED state. They may
not have a valid handle yet and simply sending a HCI_Disconnect will not
work.

This patch updates the code to either disconnect, cancel connection
creation or reject incoming connection creation based on the current
conn->state value as well as the link type in question.

When the power off procedure results in canceling connection attempts
instead of disconnecting connections we get a connection failed event
instead of a disconnection event. Therefore, we also need to have extra
code in the mgmt_connect_failed function to check if we should proceed
with the power off or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When the LE white list gets changed via HCI commands make sure that
the internal storage of the white list entries gets updated.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The current LE white list entries require storing in the HCI controller
structure. So provide a storage and access functions for it. In addition
export the current list via debugfs.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When starting up a controller make sure that all LE white list entries
are cleared. Normally the HCI Reset takes care of this. This is just
in case no HCI Reset has been executed.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Add the definitions for clearing the LE white list, adding entries to
the LE white list and removing entries from the LE white list.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The hci_blacklist_clear function is not used outside of hci_core.c and
can be made static.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The number of places needing the local Identity Address are starting to
grow so it's better to have a single place for the logic of determining
it. This patch adds a convenience function for getting the Identity
Address and updates the two current places needing this to use it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

To know the real source address for incoming connections (needed e.g.
for SMP) we should store the own_address_type parameter that was used
for the last HCI_LE_Write_Advertising_Parameters command. This patch
adds a proper command complete handler for the command and stores the
address type in a new adv_addr_type variable in the hci_dev struct.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

According to mgmt-api.txt, in case of confirm name command,
cmd_complete should be always use as a response. Not command status
as it is now for failures.
Using command complete on failure is actually better as client might
be interested in device address for which confirm name failed.
Signed-off-by: Lukasz Rymanowski <lukasz.rymanowski@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If new scanning parameters are set while background scan is running,
we should restart background scanning so these parameters are updated.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patches creates the public hci_req_add_le_passive_scan helper so
it can be re-used outside hci_core.c in the next patch.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds to debugfs the le_auto_conn file. This file will be
used to test LE auto connection infrastructure.

This file accept writes in the following format:
  "add <address> <address_type> [auto_connect]"
  "del <address> <address_type>"
  "clr"

The <address type> values are:
  * 0 for public address
  * 1 for random address

The [auto_connect] values are (for more details see struct hci_
conn_params):
  * 0 for disabled (default)
  * 1 for always
  * 2 for link loss

So for instance, if you want the kernel autonomously establishes
connections with device AA:BB:CC:DD:EE:FF (public address) every
time the device enters in connectable mode (starts advertising),
you should run the command:
$ echo "add AA:BB:CC:DD:EE:FF 0 1" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

To delete the connection parameters for that device, run the command:
$ echo "del AA:BB:CC:DD:EE:FF 0" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

To clear the connection parameters list, run the command:
$ echo "clr" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

Finally. to get the list of connection parameters configured in kernel,
read the le_auto_conn file:
$ cat /sys/kernel/debug/bluetooth/hci0/le_auto_conn

This file is created only if LE is enabled.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Only identity addresses are inserted into hdev->pend_le_conns. So,
in order to support resolvable private addresses in auto connection
mechanism, we should resolve the address before checking for pending
connections.

Thus, this patch adds an extra check in check_pending_le_conn() and
updates 'addr' and 'addr_type' variables before hci_pend_le_conn_
lookup().
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We should only accept connection parameters from identity addresses
(public or random static). Thus, we should check the address type
in hci_conn_params_add().

Additionally, since the IRK is removed during unpair, we should also
remove the connection parameters from that device.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When hdev is closed (e.g. Mgmt power off command, RFKILL or controller
is reset), the ongoing active connections are silently dropped by the
controller (no Disconnection Complete Event is sent to host). For that
reason, the devices that require HCI_AUTO_CONN_ALWAYS are not added to
hdev->pend_le_conns list and they won't auto connect.

So to fix this issue, during hdev closing, we remove all pending LE
connections. After adapter is powered on, we add a pending LE connection
for each HCI_AUTO_CONN_ALWAYS address.

This way, the auto connection mechanism works propely after a power
off and power on sequence as well as RFKILL block/unblock.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If the user sends a mgmt start discovery command while the background
scanning is running, we should temporarily stop it. Once the discovery
finishes, we start the background scanning again.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch modifies hci_conn_params_add() and hci_conn_params_del() so
they also add/delete pending LE connections according to the auto_
connect option. This way, background scan is automatically triggered/
untriggered when connection parameters are added/removed.

For instance, when a new connection parameters with HCI_AUTO_CONN_ALWAYS
option is added and we are not connected to the device, we add a pending
LE connection for that device.

Likewise, when the connection parameters are updated we add or delete
a pending LE connection according to its new auto_connect option.

Finally, when the connection parameter is deleted we also delete the
pending LE connection (if any).
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch introduces the LE auto connection options: HCI_AUTO_CONN_
ALWAYS and HCI_AUTO_CONN_LINK_LOSS. Their working mechanism are
described as follows:

The HCI_AUTO_CONN_ALWAYS option configures the kernel to always re-
establish the connection, no matter the reason the connection was
terminated. This feature is required by some LE profiles such as
HID over GATT, Health Thermometer and Blood Pressure. These profiles
require the host autonomously connect to the device as soon as it
enters in connectable mode (start advertising) so the device is able
to delivery notifications or indications.

The BT_AUTO_CONN_LINK_LOSS option configures the kernel to re-
establish the connection in case the connection was terminated due
to a link loss. This feature is required by the majority of LE
profiles such as Proximity, Find Me, Cycling Speed and Cadence and
Time.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch introduces the LE auto connection infrastructure which
will be used to implement the LE auto connection options.

In summary, the auto connection mechanism works as follows: Once the
first pending LE connection is created, the background scanning is
started. When the target device is found in range, the kernel
autonomously starts the connection attempt. If connection is
established successfully, that pending LE connection is deleted and
the background is stopped.

To achieve that, this patch introduces the hci_update_background_scan()
which controls the background scanning state. This function starts or
stops the background scanning based on the hdev->pend_le_conns list. If
there is no pending LE connection, the background scanning is stopped.
Otherwise, we start the background scanning.

Then, every time a pending LE connection is added we call hci_update_
background_scan() so the background scanning is started (in case it is
not already running). Likewise, every time a pending LE connection is
deleted we call hci_update_background_scan() so the background scanning
is stopped (in case this was the last pending LE connection) or it is
started again (in case we have more pending LE connections). Finally,
we also call hci_update_background_scan() in hci_le_conn_failed() so
the background scan is restarted in case the connection establishment
fails. This way the background scanning keeps running until all pending
LE connection are established.

At this point, resolvable addresses are not support by this
infrastructure. The proper support is added in upcoming patches.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch introduces the hdev->pend_le_conn list which holds the
device addresses the kernel should autonomously connect. It also
introduces some helper functions to manipulate the list.

The list and helper functions will be used by the next patch which
implements the LE auto connection infrastructure.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch moves address type conversion (L2CAP address type to HCI
address type) to outside hci_connect_le. This way, we avoid back and
forth address type conversion in a comming patch.

So hci_connect_le() now expects 'dst_type' parameter in HCI address
type convention.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

hci_connect() is a very simple and useless wrapper of hci_connect_acl
and hci_connect_le functions. Addtionally, all places where hci_connect
is called the link type value is passed explicitly. This way, we can
safely delete hci_connect, declare hci_connect_acl and hci_connect_le
in hci_core.h and call them directly.

No functionality is changed by this patch.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch removes hci_create_le_conn() since it is not used anymore.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Some LE controllers don't support scanning and creating a connection
at the same time. So we should always stop scanning in order to
establish the connection.

Since we may prematurely stop the discovery procedure in favor of
the connection establishment, we should also cancel hdev->le_scan_
disable delayed work and set the discovery state to DISCOVERY_STOPPED.

This change does a small improvement since it is not mandatory the
user stops scanning before connecting anymore. Moreover, this change
is required by upcoming LE auto connection mechanism in order to work
properly with controllers that don't support background scanning and
connection establishment at the same time.

In future, we might want to do a small optimization by checking if
controller is able to scan and connect at the same time. For now,
we want the simplest approach so we always stop scanning (even if
the controller is able to carry out both operations).
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds the "hci_" prefix to le_conn_failed() helper and
declares it in hci_core.h so it can be reused in hci_event.c.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch moves stop LE scanning duplicate code to one single
place and reuses it. This will avoid more duplicate code in
upcoming patches.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Now that to-be-received keys are properly tracked we no-longer need the
"force" parameter to smp_distribute_keys(). It was essentially acting as
an indicator whether all keys have been received, but now it's just
redundant together with smp->remote_key_dist.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Now that smp->remote_key_dist is tracking the keys we're still waiting
for we can use it to simplify the logic for checking whether we're done
with key distribution or not. At the same time the reliance on the
"force" parameter of smp_distribute_keys goes away and it can completely
be removed in a subsequent patch.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>