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>

To make is easier to track which keys we've received and which ones
we're still waiting for simply clear the corresponding key bits from
smp->remote_key_dist as they get received. This will allow us to
simplify the code for checking for SMP completion in subsequent patches.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The Core Specification (4.1) leaves room for sending an SMP Identity
Address Information PDU with an all-zeros BD_ADDR value. This
essentially means that we would not have an Identity Address for the
device and the only means of identifying it would be the IRK value
itself.

Due to lack of any known implementations behaving like this it's best to
keep our implementation as simple as possible as far as handling such
situations is concerned. This patch updates the Identity Address
Information handler function to simply ignore the IRK received from such
a device.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When the connectable setting is toggled using mgmt_set_connectable the
HCI_CONNECTABLE flag will only be set once the related HCI commands
succeed. When determining what kind of advertising to do we need to
therefore also check whether there is a pending Set Connectable command
in addition to the current flag value.

The enable_advertising function was already taking care of this for the
advertising type with the help of the get_adv_type function, but was
failing to do the same for the address type selection. This patch
converts the get_adv_type function to be more generic in that it returns
the expected connectable state and updates the enable_advertising
function to use the return value both for the advertising type as well
as the advertising address type.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When trying to allocate skb for new PDU, l2cap_chan is unlocked so we
can sleep waiting for memory as otherwise there's possible deadlock as
fixed in e454c844. However, in a6a5568c lock was moved from socket
to channel level and it's no longer safe to just unlock and lock again
without checking l2cap_chan state since channel can be disconnected
when lock is not held.

This patch adds missing checks for l2cap_chan state when returning from
call which allocates skb.

Scenario is easily reproducible by running rfcomm-tester in a loop.

BUG: unable to handle kernel NULL pointer dereference at         (null)
IP: [<ffffffffa0442169>] l2cap_do_send+0x29/0x120 [bluetooth]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in:
CPU: 7 PID: 4038 Comm: krfcommd Not tainted 3.14.0-rc2+ #15
Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A10 11/24/2011
task: ffff8802bdd731c0 ti: ffff8801ec986000 task.ti: ffff8801ec986000
RIP: 0010:[<ffffffffa0442169>]  [<ffffffffa0442169>] l2cap_do_send+0x29/0x120
RSP: 0018:ffff8801ec987ad8  EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8800c5796800 RCX: 0000000000000000
RDX: ffff880410e7a800 RSI: ffff8802b6c1da00 RDI: ffff8800c5796800
RBP: ffff8801ec987af8 R08: 00000000000000c0 R09: 0000000000000300
R10: 000000000000573b R11: 000000000000573a R12: ffff8802b6c1da00
R13: 0000000000000000 R14: ffff8802b6c1da00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000041257c000 CR4: 00000000000407e0
Stack:
 ffff8801ec987d78 ffff8800c5796800 ffff8801ec987d78 0000000000000000
 ffff8801ec987ba8 ffffffffa0449e37 0000000000000004 ffff8801ec987af0
 ffff8801ec987d40 0000000000000282 0000000000000000 ffffffff00000004
Call Trace:
 [<ffffffffa0449e37>] l2cap_chan_send+0xaa7/0x1120 [bluetooth]
 [<ffffffff81770100>] ? _raw_spin_unlock_bh+0x20/0x40
 [<ffffffffa045188b>] l2cap_sock_sendmsg+0xcb/0x110 [bluetooth]
 [<ffffffff81652b0f>] sock_sendmsg+0xaf/0xc0
 [<ffffffff810a8381>] ? update_curr+0x141/0x200
 [<ffffffff810a8961>] ? dequeue_entity+0x181/0x520
 [<ffffffff81652b60>] kernel_sendmsg+0x40/0x60
 [<ffffffffa04a8505>] rfcomm_send_frame+0x45/0x70 [rfcomm]
 [<ffffffff810766f0>] ? internal_add_timer+0x20/0x50
 [<ffffffffa04a8564>] rfcomm_send_cmd+0x34/0x60 [rfcomm]
 [<ffffffffa04a8605>] rfcomm_send_disc+0x75/0xa0 [rfcomm]
 [<ffffffffa04aacec>] rfcomm_run+0x8cc/0x1a30 [rfcomm]
 [<ffffffffa04aa420>] ? rfcomm_check_accept+0xc0/0xc0 [rfcomm]
 [<ffffffff8108e3a9>] kthread+0xc9/0xe0
 [<ffffffff8108e2e0>] ? flush_kthread_worker+0xb0/0xb0
 [<ffffffff817795fc>] ret_from_fork+0x7c/0xb0
 [<ffffffff8108e2e0>] ? flush_kthread_worker+0xb0/0xb0
Code: 00 00 66 66 66 66 90 55 48 89 e5 48 83 ec 20 f6 05 d6 a3 02 00 04
RIP  [<ffffffffa0442169>] l2cap_do_send+0x29/0x120 [bluetooth]
 RSP <ffff8801ec987ad8>
CR2: 0000000000000000
Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

To be friendly to user space and to behave well with controllers that
lack a proper internal power off procedure we should try to clean up as
much state as possible before requesting the HCI driver to power off.

This patch updates the power off procedure that's triggered by
mgmt_set_powered to clean any scan modes, stop LE scanning and
advertising and to disconnect any open connections.

The asynchronous cleanup procedure uses the HCI request framework,
however since HCI_Disconnect is only covered until its Command Status
event we need some extra tracking/waiting of disconnections. This is
done by monitoring when hci_conn_count() indicates that there are no
more connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_ADVERTISING flag in mgmt_advertising()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_CONNECTABLE flag in mgmt_connectable()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_DISCOVERABLE flag in mgmt_discoverable()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) starts doing disconnections we'll need to
care about any disconnections in mgmt.c and not just those with the
MGMT_CONNECTED flag set. Therefore, move the check into mgmt.c from
hci_event.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We'll soon need to make decisions on toggling the HCI_ADVERTISING flag
based on pending mgmt_set_powered commands. Therefore, move the handling
from hci_event.c into mgmt.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a convenience function to return the number of
connections in the conn_hash list. This will be useful once we update
the power off procedure to disconnect any open connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

A user space that supports the Set Privacy command is also expected to
be able to handle New IRK events. Therefore, set the HCI_RPA_RESOLVING
flag whenever the Set Privacy command is received.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When enabling non-connectable advertising, there is no need to advertise
with a public address or static address. In case LE privacy has not been
enabled a unresolvable private address will be used.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch ensures that conn->src_type contains the same address type as
is used for initiating the connection while the connection attempt is in
progress. Once connected this value will be overwritten with the
identity address type.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds support for handling the Set Privacy mgmt command,
including copying the value to hdev->irk and toggling the HCI_PRIVACY
flag.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Since we always update the random address before enabling advertising,
scanning and initiating LE connections there is no need to write the
random address add power on.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we start LE scanning we need to update the local random address if
necessary. This patch updates the code to use hci_update_random_address()
for setting the own_address_type scan parameter and updating the local
random address if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we enable advertising we need to update the local random address if
necessary. This patch takes advantage of the hci_update_random_address()
function to set the own_address_type variable and to update the local
random address if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we initiate LE connections we need to update the local random
address if necessary. This patch updates the LE connection creation
mechanism to use the new hci_update_random_address() function to set the
own_address_type parameter and to update the local random address if
necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>