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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The switch statement for the various L2CAP fixed channel handlers
is not really ordered.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Convert 0 to false and 1 to true when assigning values to bool
variables. Inspired by commit 3db1cd5c05.
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: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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 cb3b3152b2
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: Jaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: Chan-Yeol Park <chanyeol.park@samsung.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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 160dc6ac1. This patch adds a clarifying comment to the
code for this.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: John 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: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo 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: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
If we want to use l2cap_conn outside of l2cap_core.c, we need refcounting
for these objects. Otherwise, we cannot synchronize l2cap locks with
outside locks and end up with deadlocks.
Hence, introduce ref-counting for l2cap_conn objects. This doesn't affect
l2cap internals at all, as they use a direct synchronization.
We also keep a reference to the parent hci_conn for locking purposes as
l2cap_conn depends on this. This doesn't affect the connection itself but
only the lifetime of the (dead) object.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch removes the status parameter of the l2cap_conn_add function.
The parameter 'status' is always 0.
Signed-off-by: Claudio Takahasi <claudio.takahasi@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
We use _get() and _put() for device ref-counting in the kernel. However,
hci_conn_put() is _not_ used for ref-counting, hence, rename it to
hci_conn_drop() so we can later fix ref-counting and introduce
hci_conn_put().
hci_conn_hold() and hci_conn_put() are currently used to manage how long a
connection should be held alive. When the last user drops the connection,
we spawn a delayed work that performs the disconnect. Obviously, this has
nothing to do with ref-counting for the _object_ but rather for the
keep-alive of the connection.
But we really _need_ proper ref-counting for the _object_ to allow
connection-users like rfcomm-tty, HIDP or others.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Remove code which cannot execute. l2cap_conn_add for AMP_LINK
might only be invoked when receiving data in l2cap_recv_acldata.
But this case is checked in the first statement there.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Make code more readable by changing CONF_NO_FCS_RECV which is read
as "No L2CAP FCS option received" to CONF_RECV_NO_FCS which means
"Received L2CAP option NO_FCS". This flag really means that we have
received L2CAP FRAME CHECK SEQUENCE (FCS) OPTION with value "No FCS".
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
If L2CAP_FEAT_FCS is not supported we sould miss EWS option
configuration because of break. Make code more readable by
combining FCS configuration in the single block.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Before starting quering remote AMP controllers make sure
that there is local active AMP controller.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
l2cap_send_disconn_req takes 3 parameters of which conn might be
derived from chan. Make this conversion inside l2cap_send_disconn_req.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
