This patch introduces a new mgmt command for enabling/disabling BR/EDR
functionality. This can be convenient when one wants to make a dual-mode
controller behave like a single-mode one. The command is only available
for dual-mode controllers and requires that LE is enabled before using
it. The BR/EDR setting can be enabled at any point, however disabling it
requires the controller to be powered off (otherwise a "rejected"
response will be sent).

Disabling the BR/EDR setting will automatically disable all other BR/EDR
related settings.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

To allow treating dual-mode (BR/EDR/LE) controllers as single-mode ones
(LE-only) we want to introduce a new HCI_BREDR_ENABLED flag to track
whether BR/EDR is enabled or not (previously we simply looked at the
feature bit with lmp_bredr_enabled).

This patch add the new flag and updates the relevant places to test
against it instead of using lmp_bredr_enabled. The flag is by default
enabled when registering an adapter and only cleared if necessary once
the local features have been read during the HCI init procedure.

We cannot completely block BR/EDR usage in case user space uses raw HCI
sockets but the patch tries to block this in places where possible, such
as the various BR/EDR specific ioctls.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When hci_sock.c calls hci_dev_open it needs to ensure that there isn't
pending work in progress, such as that which is scheduled for the
initial setup procedure or the one for automatically powering off after
the setup procedure. This adds the necessary calls to ensure that any
previously scheduled work is completed before attempting to call
hci_dev_do_open.

This patch fixes a race with old user space versions where we might
receive a HCIDEVUP ioctl before the setup procedure has been completed.
When that happens the setup procedures callback may fail early and leave
the device in an inconsistent state, causing e.g. the setup callback to
be (incorrectly) called more than once.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The requirements of an external call to hci_dev_open from hci_sock.c are
different to that from within hci_core.c. In the former case we want to
flush any pending work in hdev->req_workqueue whereas in the latter we
don't (since there we are already calling from within the workqueue
itself). This patch does the necessary refactoring to a separate
hci_dev_do_open function (analogous to hci_dev_do_close) but does not
yet introduce the synchronizations relating to the workqueue usage.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth protocol and hardware is pretty much all little endian
and so when running sparse via "make C=2" for example, enable the
endian checks by default.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The HCI User Channel operation is an admin operation that puts the
device into promiscuous mode for single use. It is more suitable
to require CAP_NET_ADMIN than CAP_NET_RAW.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

When enabling or disabling high speed setting it is required to send
a new settings event to inform other management interface users about
the changed settings.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Hiding the Bluetooth high speed support behind a module parameter is
not really useful. This can be enabled and disabled at runtime via
the management interface. This also has the advantage that this can
now be changed per controller and not just global.

This patch removes the module parameter and exposes the high speed
setting of the management interface to all controllers.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The controller type is limited to BR/EDR/LE and AMP controllers. This
can be easily encoded with just 2 bits and still leave enough room
for future controller types.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

This patch adds a new mgmt command for enabling and disabling
LE advertising. The command depends on the LE setting being enabled
first and will return a "rejected" response otherwise. The patch also
adds safeguards so that there will ever only be one set_le or
set_advertising command pending per adapter.

The response handling and new_settings event sending is done in an
asynchronous request callback, meaning raw HCI access from user space to
enable advertising (e.g. hciconfig leadv) will not trigger the
new_settings event. This is intentional since trying to support mixed
raw HCI and mgmt access would mean adding extra state tracking or new
helper functions, essentially negating the benefit of using the
asynchronous request framework. The HCI_LE_ENABLED and HCI_LE_PERIPHERAL
flags however are updated correctly even with raw HCI access so this
will not completely break subsequent access over mgmt.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch adds a new mgmt setting for LE advertising and hooks up the
necessary places in the mgmt code to operate on the HCI_LE_PERIPHERAL
flag (which corresponds to this setting). This patch does not yet add
any new command for enabling the setting - that is left for a subsequent
patch.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch updates the code to use an asynchronous request for handling
the enabling and disabling of LE support. This refactoring is necessary
as a preparation for adding advertising support, since when LE is
disabled we should also disable advertising, and the cleanest way to do
this is to perform the two respective HCI commands in the same
asynchronous request.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The settings_rsp and cmd_status_rsp functions can be useful for all mgmt
command handlers when asynchronous request callbacks are used. They will
e.g. be used by subsequent patches to change set_le to use an async
request as well as a new set_advertising command. Therefore, move them
higher up in the mgmt.c file to avoid unnecessary forward declarations
or mixing this trivial change with other patches.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

We should return a "busy" error always when there is another
mgmt_set_powered operation in progress. Previously when powering on
while the auto off timer was still set the code could have let two or
more pending power on commands to be queued. This patch fixes the issue
by moving the check for duplicate commands to an earlier point in the
set_powered handler.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch cleans up the locking login in l2cap_sock_recvmsg by pairing
up each lock_sock call with a release_sock call. The function already
has a "done" label that handles releasing the socket and returning from
the function so the fix is rather simple.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The bt_sock_wait_state requires the sk lock to be held (through
lock_sock) so document it clearly in the code.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Convert 0 to false and 1 to true when assigning values to bool
variables. Inspired by commit 3db1cd5c.

The simplified semantic patch that find this problem is as
follows (http://coccinelle.lip6.fr/):

@@
bool b;
@@
(
-b = 0
+b = false
|
-b = 1
+b = true
)
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When the dlc is closed, rfcomm_dev_state_change() tries to release the
port in the case it cannot get a reference to the tty. However this is
racy and not even needed.

Infact as Peter Hurley points out:

1. Only consider dlcs that are 'stolen' from a connected socket, ie.
   reused. Allocated dlcs cannot have been closed prior to port
   activate and so for these dlcs a tty reference will always be avail
   in rfcomm_dev_state_change() -- except for the conditions covered by
   #2b below.
2. If a tty was at some point previously created for this rfcomm, then
   either
   (a) the tty reference is still avail, so rfcomm_dev_state_change()
       will perform a hangup. So nothing to do, or,
   (b) the tty reference is no longer avail, and the tty_port will be
       destroyed by the last tty_port_put() in rfcomm_tty_cleanup.
       Again, no action required.
3. Prior to obtaining the dlc lock in rfcomm_dev_add(),
   rfcomm_dev_state_change() will not 'see' a rfcomm_dev so nothing to
   do here.
4. After releasing the dlc lock in rfcomm_dev_add(),
   rfcomm_dev_state_change() will 'see' an incomplete rfcomm_dev if a
   tty reference could not be obtained. Again, the best thing to do here
   is nothing. Any future attempted open() will block on
   rfcomm_dev_carrier_raised(). The unconnected device will exist until
   released by ioctl(RFCOMMRELEASEDEV).

The patch removes the aforementioned code and uses the
tty_port_tty_hangup() helper to hangup the tty.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

For those controller that support the HCI_Set_Event_Mask_Page_2 command
we should include it in the init sequence. This patch implements sending
of the command and enables the events in it based on supported features
(currently only CSB is checked).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch adds support for reading the synchronization train parameters
for controllers that support the feature. Since the feature is
detectable through the local features page 2, which is retreived only in
stage 3 of the HCI init sequence, there is no other option than to add a
fourth stage to the init sequence.

For now the patch doesn't yet add storing of the parameters, but it is
nevertheless convenient to have around to see what kind of parameters
various controllers use by default (analyzable e.g. with the btmon user
space tool).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

In the case of blocking sockets we should not proceed with sendmsg() if
the socket has the BT_SK_SUSPEND flag set. So far the code was only
ensuring that POLLOUT doesn't get set for non-blocking sockets using
poll() but there was no code in place to ensure that blocking sockets do
the right thing when writing to them.

This patch adds a new bt_sock_wait_ready helper function to sleep in the
sendmsg call if the BT_SK_SUSPEND flag is set, and wake up as soon as it
is unset. It also updates the L2CAP and RFCOMM sendmsg callbacks to take
advantage of this new helper function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When we have an LE link we should not respond to any data on the BR/EDR
L2CAP signaling channel (0x0001) and vice-versa when we have a BR/EDR
link we should not respond to LE L2CAP (CID 0x0005) signaling commands.
This patch fixes this issue by checking for a valid link type and
ignores data if it is wrong.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When L2CAP packets return a non-zero error and the value is passed
onwards by l2cap_bredr_sig_cmd this will trigger a command reject packet
to be sent. However, the core specification (page 1416 in core 4.0) says
the following: "Command Reject packets should not be sent in response to
an identified Response packet.".

This patch ensures that a command reject packet is not sent for any
identified response packet by ignoring the error return value from the
response handler functions.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

There are several possible reason codes that can be sent in the command
reject L2CAP packet. Before this patch the code has used a hard-coded
single response code ("command not understood"). This patch adds a
helper function to map the return value of an L2CAP handler function to
the correct command reject reason.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

If we receive an L2CAP Disconnect Request for an unknown CID we should
not just silently drop it but reply with a proper Command Reject
response. This patch fixes this by ensuring that the disconnect handler
returns a proper error instead of 0 and will cause the function caller
to send the right response.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The EFAULT error should only be used for memory address related errors
and ENOENT might be needed for other purposes than invalid CID errors.
This patch fixes the l2cap_config_req, l2cap_connect_create_rsp and
l2cap_create_channel_req handlers to use the unique EBADSLT error to
indicate failed lookups on a given CID.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When an L2CAP request handler returns non-zero the calling code will
send a command reject response. The l2cap_create_chan_req function will
in some cases send its own response but then still return a -EFAULT
error which would cause two responses to be sent. This patch fixes this
by making the function return 0 after sending its own response.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

We need to let the setup stage complete cleanly even when the HCI device
is rfkilled. Otherwise the HCI device will stay in an undefined state
and never get notified to user space through mgmt (even when it gets
unblocked through rfkill).

This patch makes sure that hci_dev_open() can be called in the HCI_SETUP
stage, that blocking the device doesn't abort the setup stage, and that
the device gets proper powered down as soon as the setup stage completes
in case it was blocked meanwhile.

The bug that this patch fixed can be very easily reproduced using e.g.
the rfkill command line too. By running "rfkill block all" before
inserting a Bluetooth dongle the resulting HCI device goes into a state
where it is never announced over mgmt, not even when "rfkill unblock all"
is run.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This makes it more convenient to check for rfkill (no need to check for
dev->rfkill before calling rfkill_blocked()) and also avoids potential
races if the RFKILL state needs to be checked from within the rfkill
callback.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

For certain devices (ex: HID mouse), support for authentication,
pairing and bonding is optional. For such devices, the ACL alive
for too long after the L2CAP disconnection.

To avoid the ACL alive for too long after L2CAP disconnection, reset the
ACL disconnect timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.

While merging the commit id:a9ea3ed9
this issue might have introduced.

Hcidump info:
sh-4.1# /opt/hcidump -Xt
2013-08-05 16:49:00.894129 < ACL data: handle 12 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004a scid 0x0041
2013-08-05 16:49:00.894195 < HCI Command: Exit Sniff Mode (0x02|0x0004)
    plen 2
    handle 12
2013-08-05 16:49:00.894269 < ACL data: handle 12 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x0049 scid 0x0040
2013-08-05 16:49:00.895645 > HCI Event: Command Status (0x0f) plen 4
    Exit Sniff Mode (0x02|0x0004) status 0x00 ncmd 1
2013-08-05 16:49:00.934391 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:49:00.936592 > HCI Event: Number of Completed Packets
    (0x13) plen 5
    handle 12 packets 2
2013-08-05 16:49:00.951577 > ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004a scid 0x0041
2013-08-05 16:49:00.952820 > ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x0049 scid 0x0040
2013-08-05 16:49:00.969165 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x02 interval 50
    Mode: Sniff

2013-08-05 16:49:48.175533 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:49:48.219045 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x02 interval 108
    Mode: Sniff

2013-08-05 16:51:00.968209 < HCI Command: Disconnect (0x01|0x0006) plen 3
    handle 12 reason 0x13
    Reason: Remote User Terminated Connection
2013-08-05 16:51:00.969056 > HCI Event: Command Status (0x0f) plen 4
    Disconnect (0x01|0x0006) status 0x00 ncmd 1
2013-08-05 16:51:01.013495 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:51:01.073777 > HCI Event: Disconn Complete (0x05) plen 4
    status 0x00 handle 12 reason 0x16
    Reason: Connection Terminated by Local Host

============================ After  fix ================================

2013-08-05 16:57:35.986648 < ACL data: handle 11 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004c scid 0x0041
2013-08-05 16:57:35.986713 < HCI Command: Exit Sniff Mode (0x02|0x0004)
    plen 2
    handle 11
2013-08-05 16:57:35.986785 < ACL data: handle 11 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004b scid 0x0040
2013-08-05 16:57:35.988110 > HCI Event: Command Status (0x0f) plen 4
    Exit Sniff Mode (0x02|0x0004) status 0x00 ncmd 1
2013-08-05 16:57:36.030714 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:57:36.032950 > HCI Event: Number of Completed Packets
    (0x13) plen 5
    handle 11 packets 2
2013-08-05 16:57:36.047926 > ACL data: handle 11 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004c scid 0x0041
2013-08-05 16:57:36.049200 > ACL data: handle 11 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004b scid 0x0040
2013-08-05 16:57:36.065509 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x02 interval 50
    Mode: Sniff

2013-08-05 16:57:40.052006 < HCI Command: Disconnect (0x01|0x0006) plen 3
    handle 11 reason 0x13
    Reason: Remote User Terminated Connection
2013-08-05 16:57:40.052869 > HCI Event: Command Status (0x0f) plen 4
    Disconnect (0x01|0x0006) status 0x00 ncmd 1
2013-08-05 16:57:40.104731 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:57:40.146935 > HCI Event: Disconn Complete (0x05) plen 4
    status 0x00 handle 11 reason 0x16
    Reason: Connection Terminated by Local Host
Signed-off-by: NSang-Ki Park <sangki79.park@samsung.com>
Signed-off-by: NChan-yeol Park <chanyeol.park@samsung.com>
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NSzymon Janc <szymon.janc@tieto.com>
Signed-off-by: NSyam Sidhardhan <s.syam@samsung.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch fixes the connection encryption key size information when
the host is playing the peripheral role. We should set conn->enc_key_
size in hci_le_ltk_request_evt, otherwise it is left uninitialized.

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

While playing the peripheral role, the host gets a LE Long Term Key
Request Event from the controller when a connection is established
with a bonded device. The host then informs the LTK which should be
used for the connection. Once the link is encrypted, the host gets
an Encryption Change Event.

Therefore we should set conn->pending_sec_level instead of conn->
sec_level in hci_le_ltk_request_evt. This way, conn->sec_level is
properly updated in hci_encrypt_change_evt.

Moreover, since we have a LTK associated to the device, we have at
least BT_SECURITY_MEDIUM security level.

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: NAndre Guedes <andre.guedes@openbossa.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When the user channel is set and an user application has full control
over the device, do not bother trying to schedule any queues except
the raw queue.

This is an optimization since with user channel, only the raw queue
is in use.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

There is no need to use GFP_ATOMIC with skb_clone() when the code is
executed in a workqueue.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When the device has the user channel flag set, it means it is driven by
an user application. In that case do not allow any connections from
L2CAP or SCO sockets.

This is the same situation as when the device has the raw flag set and
it will then return EHOSTUNREACH.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch introcuces a new HCI socket channel that allows user
applications to take control over a specific HCI device. The application
gains exclusive access to this device and forces the kernel to stay away
and not manage it. In case of the management interface it will actually
hide the device.

Such operation is useful for security testing tools that need to operate
underneath the Bluetooth stack and need full control over a device. The
advantage here is that the kernel still provides the service of hardware
abstraction and HCI level access. The use of Bluetooth drivers for
hardware access also means that sniffing tools like btmon or hcidump
are still working and the whole set of transaction can be traced with
existing tools.

With the new channel it is possible to send HCI commands, ACL and SCO
data packets and receive HCI events, ACL and SCO packets from the
device. The format follows the well established H:4 protocol.

The new HCI user channel can only be established when a device has been
through its setup routine and is currently powered down. This is
enforced to not cause any problems with current operations. In addition
only one user channel per HCI device is allowed. It is exclusive access
for one user application. Access to this channel is limited to process
with CAP_NET_RAW capability.

Using this new facility does not require any external library or special
ioctl or socket filters. Just create the socket and bind it. After that
the file descriptor is ready to speak H:4 protocol.

        struct sockaddr_hci addr;
        int fd;

        fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);

        memset(&addr, 0, sizeof(addr));
        addr.hci_family = AF_BLUETOOTH;
        addr.hci_dev = 0;
        addr.hci_channel = HCI_CHANNEL_USER;

        bind(fd, (struct sockaddr *) &addr, sizeof(addr));

The example shows on how to create a user channel for hci0 device. Error
handling has been left out of the example. However with the limitations
mentioned above it is advised to handle errors. Binding of the user
cahnnel socket can fail for various reasons. Specifically if the device
is currently activated by BlueZ or if the access permissions are not
present.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch introduces a new user channel flag that allows to give full
control of a HCI device to a user application. The kernel will stay away
from the device and does not allow any further modifications of the
device states.

The existing raw flag is not used since it has a bit of unclear meaning
due to its legacy. Using a new flag makes the code clearer.

A device with the user channel flag set can still be enumerate using the
legacy API, but it does not longer enumerate using the new management
interface used by BlueZ 5 and beyond. This is intentional to not confuse
users of modern systems.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The various legacy ioctls used with HCI sockets are limited to raw
channel only. They are not used on the other channels and also have
no meaning there. So return an error if tried to use them.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The HCI sockets for monitor and control do not support any HCI specific
socket options and if tried, an error will be returned. However the
error used is EINVAL and that is not really descriptive. To make it
clear that these sockets are not handling HCI socket options, return
EBADFD instead.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Even if this is legacy API, there is no reason to not report a proper
error when trying to reset a HCI device that is down.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>