To avoid flooding the host with useless advertising reports during
background scan, we enable the duplicates filter from controller.

However, enabling duplicates filter requires a small change in
background scan routine in order to fix the following scenario:
  1) Background scan is running.
  2) A device disconnects and starts advertising.
  3) Before host gets the disconnect event, the advertising is reported
     to host. Since there is no pending LE connection at that time,
     nothing happens.
  4) Host gets the disconnection event and adds a pending connection.
  5) No advertising is reported (since controller is filtering) and the
     connection is never established.

So, to address this scenario, we should always restart background scan
to unsure we don't miss any advertising report (due to duplicates
filter).
Signed-off-by: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel 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: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan 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: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan 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: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan 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: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan 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: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel 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: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The RPA expiry timer is only initialized inside mgmt.c when we receive
the first command from user space. This action also involves setting the
HCI_MGMT flag for the first time so that flag acts as a good indicator
of whether the delayed work variable can be touched or not. This patch
fixes hci_dev_do_close to first check the flag.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The identity information in debugfs currently do not include the
current in use local RPA. Since the RPA is now stored in the
controller information, include it in the debugfs as well.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The RPA needs to be stored to know which is the current one. Otherwise
it is impossible to ensure that always the correct RPA can be programmed
into the controller when it is needed.

Current code checks if the address in the controller is a RPA, but that
can potentially lead to using a RPA that can not be resolved with the
IRK that has been distributed.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

When running active scanning during LE discovery, do not reveal the own
identity to the peer devices. In case LE privacy has been enabled, then
a resolvable private address is used. If the LE privacy option is off,
then use an unresolvable private address.

The public address or static random address is never used in active
scanning anymore. This ensures that scan request are send using a
random address.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

When using LE Privacy it is useful to know the local identity address,
identity address type and identity resolving key. For debugging purposes
add these information to debugfs.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Now that the identity address type is always looked up for all
successful connections, the hdev->own_addr_type variable has become
completely unnecessary. Simply remove it.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds a rpa_timeout debugfs entry which can be used to set the
RPA regeneration timeout to something else than the default 15 minutes.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds a convenience function for updating the local random
address which is needed before advertising, scanning and initiating LE
connections.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds a timer for updating the local RPA periodically. The
default timeout is set to 15 minutes.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We should be iterating hdev->identity_resolving_keys in the
hci_remove_irk() function instead of hdev->long_term_keys. This patch
fixes the issue.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

For testing purposes it is useful to provide an option to change the
advertising channel map. So add a debugfs option to allow this.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

For Bluetooth controllers with LE support, track the value of the
currently configured random address. It is important to know what
the current random address is to avoid unneeded attempts to set
a new address. This will become important when introducing the
LE privacy support in the future.

In addition expose the current configured random address via
debugfs for debugging purposes.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The own_address_type debugfs option does not providing enough
flexibity for interacting with the upcoming LE privacy support.

What really is needed is an option to force using the static address
compared to the public address. The new force_static_address debugfs
option does exactly that. In addition it is also only available when
the controller does actually have a public address. For single mode
LE only controllers this option will not be available.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

This patch moves the SMP Long Term Key notification over mgmt from the
hci_add_ltk function to smp.c when both sides have completed their key
distribution. This way we are also able to update the identity address
into the mgmt_new_ltk event.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

It's simpler (one less if-statement) to just evaluate the appropriate
value for store_hint in the mgmt_new_ltk function than to pass a boolean
parameter to the function. Furthermore, this simplifies moving the mgmt
event emission out from hci_add_ltk in subsequent patches.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The SMP code will need to postpone the mgmt event emission for the IRK
and LTKs. To avoid extra lookups at the end of the key distribution
simply return the added value from the add_ltk and add_irk functions.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The various pieces of data cached in the hci_dev structure do not need
to be allocated using GFP_ATOMIC since they are never added from
interrupt context. This patch updates these allocations to use
GFP_KERNEL instead.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For debugging purposes expose the current list of identity resolving
keys via debugfs. This file is read-only and limited to root access.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Identity Addresses are either public or static random. When looking up
addresses based on the Identity Address it doesn't make sense to go
through the IRK list if we're given a private random address. This patch
fixes (or rather improves) the hci_find_irk_by_addr function to bail out
early if given a private random address.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When mgmt_unpair_device is called we should also remove any associated
IRKs. This patch adds a hci_remove_irk convenience function and ensures
that it's called when mgmt_unpair_device is called.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There is code (in mgmt.c) that depends on the hci_remove_ltk function to
fail if no match is found. This patch adds tracking of removed LTKs
(there can be up to two: one for master and another for slave) in the
hci_remove_ltk function and returns -ENOENT of no matches were found.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There are many functions that never fail but still declare an integer
return value for no reason. This patch converts these functions to use a
void return value to avoid any confusion of whether they can fail or not.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When removing Long Term Keys we should also be checking that the given
address type (public vs random) matches. This patch updates the
hci_remove_ltk function to take an extra parameter and uses it for
address type matching.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>