This is a rewrite of the HIDP session management. It implements HIDP as an
l2cap_user sub-module so we get proper notification when the underlying
connection goes away.

The helpers are not yet used but only added in this commit. The old
session management is still used and will be removed in a following patch.

The old session-management was flawed. Hotplugging is horribly broken and
we have no way of getting notified when the underlying connection goes
down. The whole idea of removing the HID/input sub-devices from within the
session itself is broken and suffers from major dead-locks. We never can
guarantee that the session can unregister itself as long as we use
synchronous shutdowns. This can only work with asynchronous shutdowns.
However, in this case we _must_ be able to unregister the session from the
outside as otherwise the l2cap_conn object might be unlinked before we
are.

The new session-management is based on l2cap_user. There is only one
way how to add a session and how to delete a session: "probe" and "remove"
callbacks from l2cap_user.
This guarantees that the session can be registered and unregistered at
_any_ time without any synchronous shutdown.
On the other hand, much work has been put into proper session-refcounting.
We can unregister/unlink the session only if we can guarantee that it will
stay alive. But for asynchronous shutdowns we never know when the last
user goes away so we must use proper ref-counting.

The old ->conn field has been renamed to ->hconn so we can reuse ->conn in
the new session management. No other existing HIDP code is modified.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

There is no reason to keep this helper in the header file. No other file
depends on it so move it into hidp/core.c where it belongs.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The "terminate" flag is guaranteed to be set before the session terminates
and the handlers are woken up. Hence, we need to add it to the
sleep-condition.

Note that testing the flags is not enough as nothing prevents us from
setting the flags again after the session-handler terminated.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This field is always BT_CONNECTED. Remove it and set it to BT_CONNECTED in
hidp_copy_session() unconditionally.

Also note that this field is totally bogus. Userspace can query an
hidp-session for its state. However, whenever user-space queries us, this
field should be BT_CONNECTED. If it wasn't BT_CONNECTED, then we would be
currently cleaning up the session and the session itself would exit in the
next few milliseconds. Hence, there is no reason to let user-space know
that the session will exit now if they cannot make _any_ use of that.

Thus, remove the field and let user-space think that a session is always
BT_CONNECTED as long as they can query it.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

hci_conn_hold/put_device() is used to control when hci_conn->dev is no
longer needed and can be deleted from the system. Lets first look how they
are currently used throughout the code (excluding HIDP!).

All code that uses hci_conn_hold_device() looks like this:
    ...
    hci_conn_hold_device();
    hci_conn_add_sysfs();
    ...
On the other side, hci_conn_put_device() is exclusively used in
hci_conn_del().

So, considering that hci_conn_del() must not be called twice (which would
fail horribly), we know that hci_conn_put_device() is only called _once_
(which is in hci_conn_del()).
On the other hand, hci_conn_add_sysfs() must not be called twice, either
(it would call device_add twice, which breaks the device, see
drivers/base/core.c). So we know that hci_conn_hold_device() is also
called only once (it's only called directly before hci_conn_add_sysfs()).

So hold and put are known to be called only once. That means we can safely
remove them and directly call hci_conn_del_sysfs() in hci_conn_del().

But there is one issue left: HIDP also uses hci_conn_hold/put_device().
However, this case can be ignored and simply removed as it is totally
broken. The issue is, the only thing HIDP delays with
hci_conn_hold_device() is the removal of the hci_conn->dev from sysfs.
But, the hci_conn device has no mechanism to get notified when its own
parent (hci_dev) gets removed from sysfs. hci_dev_hold/put() does _not_
control when it is removed but only when the device object is created
and destroyed.
And hci_dev calls hci_conn_flush_*() when it removes itself from sysfs,
which itself causes hci_conn_del() to be called, but it does _not_ cause
hci_conn_del_sysfs() to be called, which is wrong.

Hence, we fix it to call hci_conn_del_sysfs() in hci_conn_del(). This
guarantees that a hci_conn object is removed from sysfs _before_ its
parent hci_dev is removed.

The changes to HIDP look scary, wrong and broken. However, if you look at
the HIDP session management, you will notice they're already broken in the
exact _same_ way (ever tried "unplugging" HIDP devices? Breaks _all_ the
time).
So this patch only makes HIDP look _scary_ and _obviously broken_. It does
not break HIDP itself, it already is!

See later patches in this series which fix HIDP to use proper
session-management.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

We need to verify that the given sockets actually are l2cap sockets. If
they aren't, we are not supposed to access bt_sk(sock) and we shouldn't
start the session if the offsets turn out to be valid local BT addresses.

That is, if someone passes a TCP socket to HIDCONNADD, then we access some
random offset in the TCP socket (which isn't even guaranteed to be valid).

Fix this by checking that the socket is an l2cap socket.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

After linux 3.2 the hid_destroy_device call in hidp_session
cleaning up invokes a hook to the power_supply code which
in turn tries to read the battery capacity. This read will
trigger a call to hidp_get_raw_report which is bound to fail
because the device is being taken away - so rather than
wait for the 5 second timeout failure this changes enables
it to fail straight away.
Signed-off-by: NKarl Relton <karllinuxtest.relton@ntlworld.com>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The length parameter should be sizeof(req->name) - 1 because there is no
guarantee that string provided by userspace will contain the trailing
'\0'.

Can be easily reproduced by manually setting req->name to 128 non-zero
bytes prior to ioctl(HIDPCONNADD) and checking the device name setup on
input subsystem:

$ cat /sys/devices/pnp0/00\:04/tty/ttyS0/hci0/hci0\:1/input8/name
AAAAAA[...]AAAAAAAAf0:af:f0:af:f0:af

("f0:af:f0:af:f0:af" is the device bluetooth address, taken from "phys"
field in struct hid_device due to overflow.)

Cc: stable@vger.kernel.org
Signed-off-by: NAnderson Lizardo <anderson.lizardo@openbossa.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch against kernel 3.7.0-rc8 fixes a kernel oops when turning on the
bluetooth mouse with id 0458:0058 [1].

The mouse in question supports both input and hid sessions, however it is
blacklisted in drivers/hid/hid-core.c so the input session is one that should
be used. Long ago (around kernel 3.0.0) some changes in the bluetooth
subsystem made the kernel do not fallback to input session when hid session is
not supported or blacklisted. This patch restore that behaviour by making the
kernel try the input session if hid_add_device returns ENODEV.

The patch exports hid_ignore() from hid-core.c so that it can be used in the
bluetooth subsystem.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=39882Signed-off-by: NLamarque V. Souza <lamarque@gmail.com>
Acked-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Instead of old unsafe batostr function use %pMR print specifier
for printing Bluetooth addresses in sprintf and seq_printf
statements.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Follow the net rules.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Most of the include were unnecessary or already included by some other
header.
Replace module.h by export.h where possible.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Only obvious cases were left as inline, mostly oneline functions.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Move the hid drivers of the bus drivers to a common generic hid
driver, and make it a proper module. This ought to simplify device
handling moving forward.

Cc: Gustavo Padovan <gustavo@padovan.org>
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Devices that do not have a special driver are handled by the generic
driver. This patch does the same thing using device groups; Instead of
forcing a particular driver, the appropriate driver is picked up by
udev. As a consequence, one can now move a device from generic to
specific handling by a simple rebind. By adding a new device id to the
generic driver, the same thing can be done in reverse.
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>
Acked-by: NBenjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Now we run everything in HCI in process context, so it's a better idea use
mutex instead spin_lock. The macro remains hci_dev_lock() (and I got rid
of hci_dev_lock_bh()), of course.
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

This functions needs crtl_sock and intr_sock to be set first.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Calling module_put(THIS_MODULE) is *never* safe when we cannot go sure that we
own at least two references. This is because the call may unload our module
before it returns and then the "return" will jump into invalid memory.

Gladly, module.h provides a wrapper for kthread-users: module_put_and_exit().
This puts our module and then exits the kthread without returning to the module.

This patch fixes the hidp kthread to use this wrapper instead of manually
freeing its own reference. See nfsd or lockd for other kthreads using this.

Calling __module_get() inside the kthread is safe as the hidp module will always
wait until the kthread sets "waiting_for_startup" to 0.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When all items in the list have the same type there is no much of a point
to use list_for_each except if you want to use the list pointer itself.
Signed-off-by: NLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

hidp_get_connection() makes more sense because we hold a reference to the
connection inside this function.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

It gets allocated only when it is really needed.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Claim device lock to safely enumerate hci connection list and bump
hci connection proxy device ref count simultaneously.

This patch incorporates David Herrmann's fix to prevent adding an
HID device when the hci connection no longer exists.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

d458a9df add this check, but now it proves to be wrong.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

This is a regression fix. It made impossible use input device when hid
fails.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

interrupt channel is low latency.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Interrupt channel has low latency requiments, should be processed first.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

list_for_each_entry is much more meaningful.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Current hidp driver purges the in/out queue on HID shutdown, but does
not prevent further I/O. If a driver uses hidp_output_raw_report or
hidp_get_raw_report during shutdown, the driver hangs for 5 or 10
seconds per call until it gets a timeout.
That is, if the output queue of an HID driver has 10 messages pending,
it will take 50s until hid_destroy_device() will return. The
hidp_session_sem semaphore is held during shutdown so no other HID
device may be added/removed during this time.

This patch makes hidp_output_raw_report and hidp_get_raw_report fail if
session->terminate is true. Also hidp_session will wakeup all current
calls to these functions to cancel the current operations.

We already purge the current I/O queues on hidp_stop(), so this data loss
does not change the behaviour of the HID drivers.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Fragmented skbs are only encountered when receiving ERTM or streaming
mode L2CAP data.  BNEP, CMTP, HIDP, and RFCOMM generally use basic
mode, but they need to handle fragments without crashing.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

During setup the host initializes all HID reports. Some devices do not
support this. If this quirk is set, we skip the initialization.
See also usbhid_init_reports() for this quirk.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When an hidp connection is added for a boot protocol input
device, don't release a device reference that was never
acquired. The device reference is acquired when the session
is linked to the session list (which hasn't happened yet when
hidp_setup_input is called).
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When an hidp connection is added for a boot protocol input
device, only free the allocated device if device registration fails.
Subsequent failures should only unregister the device (the input
device api documents that unregister will also free the allocated
device).
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Free the cached HID report descriptor on thread terminate.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Once the session thread is running, cleanup must be
handled by the session thread only.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Partial revert of commit aabf6f89. When the hidp session thread
was converted from kernel_thread to kthread, the atomic/wakeups
were replaced with kthread_stop. kthread_stop has blocking semantics
which are inappropriate for the hidp session kthread. In addition,
the kthread signals itself to terminate in hidp_process_hid_control()
- it cannot do this with kthread_stop().

Lastly, a wakeup can be lost if the wakeup happens between checking
for the loop exit condition and setting the current state to
TASK_INTERRUPTIBLE. (Without appropriate synchronization mechanisms,
the task state should not be changed between the condition test and
the yield - via schedule() - as this creates a race between the
wakeup and resetting the state back to interruptible.)
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

In this commit, omtu, imtu, flush_to, mode and sport. It also remove the
pi var from l2cap_sock_sendmsg().
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

kernel_thread() is a low-level implementation detail and
EXPORT_SYMBOL(kernel_thread) is scheduled for removal.
Use the <linux/kthread.h> API instead.
Signed-off-by: NSzymon Janc <szymon.janc@tieto.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Signed-off-by: NSzymon Janc <szymon.janc@tieto.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

The current implementation of hidp_output_raw_report() relies only on
the Control channel even for Output reports, and the BT HID
specification [1] does not mention using the DATA message for Output
reports on the Control channel (see section 7.9.1 and also Figure 11:
SET_ Flow Chart), so let us just use SET_REPORT.

This also fixes sending Output reports to some devices (like Sony
Sixaxis) which are not able to handle DATA messages on the Control
channel.

Ideally hidp_output_raw_report() could be improved to use this scheme:
  Feature Report -- SET_REPORT on the Control channel
  Output Report  -- DATA on the Interrupt channel
for more efficiency, but as said above, right now only the Control
channel is used.

[1] http://www.bluetooth.com/Specification%20Documents/HID_SPEC_V10.pdfSigned-off-by: NAntonio Ospite <ospite@studenti.unina.it>
Acked-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>