The a2mp.h header file is only used internally by the bluetooth.ko
module and is not a public API. So make it local to the core
Bluetooth module.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The amp.h header file is only used internally by the bluetooth.ko
module and is not a public API. So make it local to the core
Bluetooth module.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The l2cap_recv_frame function is expected to take ownership and
eventually free the skb passed to it. We need to ensure that the
conn->rx_skb pointer is no longer reachable when calling
l2cap_recv_frame so that no other function, such as l2cap_conn_del, may
think that it can free conn->rx_skb.

An actual situation when this can happen is when smp_sig_channel (called
from l2cap_recv_frame) fails and l2cap_conn_del gets called as a
consequence. The l2cap_conn_del function would then try to free
conn->rx_skb, but as the same skb was just passed to smp_sig_channel and
freed we get a double-free.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The check if a L2CAP connection is AMP capable was a little bit
complicated. This changes the code to make it simpler and more
readable.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The hci_amp_capable() function has only a single user inside the L2CAP
core. Instead of exporting the function, place it next to its user.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The special AMP controller id 0 is reserved for the BR/EDR controller
that has the main link. It is a fixed value and so use a constant for
this throughout the code to make it more visible when the handling is
for the BR/EDR channel or when it is for the AMP channel.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The Bluetooth specification makes it clear that only one command
should be present in the L2CAP LE signalling packet. So tighten
the checks here and restrict it to exactly one command.

This is different from L2CAP BR/EDR signalling where multiple
commands can be part of the same packet.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The ATT fixed channel is only valid when using LE connections. On
BR/EDR it is required to go through L2CAP connection oriented
channel for ATT.

Drop ATT packets when they are received on a BR/EDR connection.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

When receiving connectionless packets on a LE connection, just drop
the packet. There is no concept of connectionless channels for LE.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The L2CAP raw sockets are only used for BR/EDR signalling. Packets
on LE links should not be forwarded there.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The switch statement for the various L2CAP fixed channel handlers
is not really ordered.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The wrong type of L2CAP signalling packets on the wrong type of
either BR/EDR or LE links need to be dropped. When that happens
the packet is dropped, but the memory not freed. So actually
free the memory as well.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

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>

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 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>

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>

The length check is invalid since the length varies with type of
info response.

This was introduced by the commit cb3b3152

Because of this, l2cap info rsp is not handled and command reject is sent.

> ACL data: handle 11 flags 0x02 dlen 16
        L2CAP(s): Info rsp: type 2 result 0
          Extended feature mask 0x00b8
            Enhanced Retransmission mode
            Streaming mode
            FCS Option
            Fixed Channels
< ACL data: handle 11 flags 0x00 dlen 10
        L2CAP(s): Command rej: reason 0
          Command not understood

Cc: stable@vger.kernel.org
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NChan-Yeol Park <chanyeol.park@samsung.com>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Trivial change in the coding style.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The length check is invalid since the length varies with type of
info response.

This was introduced by the commit cb3b3152

Because of this, l2cap info rsp is not handled and command reject is sent.

> ACL data: handle 11 flags 0x02 dlen 16
        L2CAP(s): Info rsp: type 2 result 0
          Extended feature mask 0x00b8
            Enhanced Retransmission mode
            Streaming mode
            FCS Option
            Fixed Channels
< ACL data: handle 11 flags 0x00 dlen 10
        L2CAP(s): Command rej: reason 0
          Command not understood

Cc: stable@vger.kernel.org
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NChan-Yeol Park <chanyeol.park@samsung.com>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The LE ATT server socket needs to be superseded by any ATT client
sockets. Previously this was done by looking at the hcon->out variable
(indicating whether the connection is outgoing or incoming) which is a
too crude way of determining whether the server socket needs to be
picked or not (an outgoing connection doesn't necessarily mean that an
ATT client socket has triggered it).

This patch extends the ATT server socket lookup function
(l2cap_le_conn_ready) to be used for all LE connections (regardless of
the hcon->out value) and adds an internal check into the function for
the existence of any ATT client sockets (in which case the server socket
should be skipped). For this to work reliably all lookups must be done
while the l2cap_conn->chan_lock is held, meaning also that the call to
l2cap_chan_add needs to be changed to its lockless __l2cap_chan_add
counterpart.
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's no need to reset disc_timeout in l2cap_le_conn_ready since
HCI_DISCONN_TIMEOUT is the default when the hci_conn is created and
there should be no way for it to get changed between creation and
l2cap_le_conn_ready being called.
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 L2CAP code has been incrementing the hci_conn reference for each
l2cap_chan instance in the l2cap_conn list. Likewise, the reference is
dropped each time an l2cap_chan is removed from the list. The reference
counting policy with respect to removal has been clear and explicit in
the l2cap_chan_del function, however for addition the function
calling 2cap_chan_add has always had to do a separate hci_conn_hold
call.

What made the counting even more hard to follow is that the
hci_connect() procedure increments the reference and the L2CAP layer
making this call took advantage of it to use it as its own reference.

This patch aims to clarify things by having the call to hci_conn_hold
inside __l2cap_chan_add, thereby removing the need to do it in the
functions calling __l2cap_chan_add. The reference count for hci_connect
is still kept as it's necessary for users such as mgmt_pair_device,
however for the L2CAP layer it means that an extra call to hci_conn_drop
must be performed once l2cap_chan_add has been done.
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 l2cap_att_channel() we're only interested in the BT_CONNECTED state
so this state can directly be passed to l2cap_global_chan_by_scid().
This way there's no need to do any additional state check later.
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 sk variable is of quite little use since it's only used to simplify
access in the two bt_sk() calls.
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 l2cap_le_conn_ready() after doing l2cap_chann_add() the LE channel is
part of the list which is subsequently iterated in l2cap_conn_ready() in
this loop each channel will get l2cap_chan_ready() called which would
result in trying to set the channel two times into BT_CONNECTED state.
Instead it makes sense to just add the channel but not call chan_ready
in l2cap_le_conn_ready, which is what this patch does.
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 is an extra call to smp_conn_security() for outgoing LE
connections from l2cap_conn_ready() but the reason for this call is far
from clear. After a bit of commit history research and using git blame I
found out that this extra call is for socket-less pairing processes
added by commit 160dc6ac. This patch adds a clarifying comment to the
code for this.
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>

Since in the future more than the ATT CID may be permissible we should
not be hardcoding it for all LE connections in __l2cap_chan_add().
Instead, the source ATT CID should only be set if the destination is
also ATT, and in other cases we should just use the existing dynamic CID
allocation function.

Assigning scid based on dcid means that whenever __l2cap_chan_add() is
called that chan->dcid is properly initialized. l2cap_le_conn_ready()
wasn't initializing is properly so this is also taken care of in this
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>

The current test in l2cap_chan_connect is intended to protect against
multiple conflicting connect attempts. However, it assumes that there
will ever only be a single CID that is connected to, which is not true.
We do need to check for conflicts with connect attempts to the same
destination CID but this check is not in anyway specific to LE but can
be applied to BR/EDR as well.
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 choice between LE and BR/EDR should be made on the destination
address type instead of the destination CID. This is particularly
important when in the future more than one CID will be allowed for LE.
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 future Core Specification versions the ATT CID will be just one of
many possible CIDs that can be used for data transfer. Therefore, it
makes sense to rename the define for the ATT CID to something less
ambigous.
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 LE L2CAP signalling channel follows its own rules and will continue
to evolve independently from the BR/EDR signalling channel. Therefore,
it makes sense to have a clear split from BR/EDR by having a dedicated
function for handling LE signalling commands.
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 a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---
Signed-off-by: NAnderson Lizardo <anderson.lizardo@openbossa.org>
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There has been code in place to check that the L2CAP length header
matches the amount of data received, but many PDU handlers have not been
checking that the data received actually matches that expected by the
specific PDU. This patch adds passing the length header to the specific
handler functions and ensures that those functions fail cleanly in the
case of an incorrect amount of data.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The CID is fixed to L2CAP ATT channel and so there is no need to hand it
down to the handling function. Just use a constant instead.
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>

Several sub-modules like HIDP, rfcomm, ... need to track l2cap
connections. The l2cap_conn->hcon->dev object is used as parent for sysfs
devices so the sub-modules need to be notified when the hci_conn object is
removed from sysfs.

As submodules normally use the l2cap layer, the l2cap_user objects are
registered there instead of on the underlying hci_conn object. This avoids
any direct dependency on the HCI layer and lets the l2cap core handle any
specifics.

This patch introduces l2cap_user objects which contain a "probe" and
"remove" callback. You can register them on any l2cap_conn object and if
it is active, the "probe" callback will get called. Otherwise, an error is
returned.

The l2cap_conn object will call your "remove" callback directly before it
is removed from user-space. This allows you to remove your submodules
_before_ the parent l2cap_conn and hci_conn object is removed.

At any time you can asynchronously unregister your l2cap_user object if
your submodule vanishes before the l2cap_conn object does.

There is no way around l2cap_user. If we want wire-protocols in the
kernel, we always want the hci_conn object as parent in the sysfs tree. We
cannot use a channel here since we might need multiple channels for a
single protocol.
But the problem is, we _must_ get notified when an l2cap_conn object is
removed. We cannot use reference-counting for object-removal! This is not
how it works. If a hardware is removed, we should immediately remove the
object from sysfs. Any other behavior would be inconsistent with the rest
of the system. Also note that device_del() might sleep, but it doesn't
wait for user-space or block very long. It only _unlinks_ the object from
sysfs and the whole device-tree. Everything else is handled by ref-counts!
This is exactly what the other sub-modules must do: unlink their devices
when the "remove" l2cap_user callback is called. They should not do any
cleanup or synchronous shutdowns.
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>