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>
When receiving L2CAP Create Channel Request set the channel as
L2CAP_FCS_NONE. Then in "L2CAP Config req" following field will
be set: "FCS Option 0x00 (No FCS)". So by default High Speed
channels have no FCS.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When receiving Physical Link Completed event we need to create L2CAP
channel with L2CAP Create Chan Request. Current code was sending
this command only if connection was pending (which is probably
needed in channel move case). If channel is not moved but created
Create Chan should be sent for outgoing channel which is checked
with BT_CONNECT flag.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Set chan->fcs to L2CAP_FCS_NONE only for new L2CAP channels
(not moved). Other side can still request to use FCS.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
local_amp_id is already set in l2cap_connect() which is called several
lines above.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Use helper instead of test_bit. This is the only place left using
test CONF_CONNECT_PEND flag.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Since we have started to use local_amp_id for local AMP
Controller Id it makes sense to rename ctrl_id to remote_amp_id
since it represents remote AMP controller Id.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Add processing L2CAP Create Chan Request. When channel is created
save associated high speed link hs_hcon.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When deciding whether to send EFS configuration response with success,
check rather for existence of High Speed physical link hs_hcon then
ctrl_id. There might be cases when there is ctrl_id but high speed link
is not established yet.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Disconnect logical link for high speed channel hs_hchan
associated with L2CAP channel chan.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
After physical link is created logical link needs to be created.
The process starts after L2CAP channel is created and L2CAP
Configuration Response with result PENDING is received.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When logical link creation is completed we need to save hs_hchan
which represents logical link instead of hs_hcon representing
physical link. hs_hcon shall be saved when receiving physical link
complete event.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
There is helper function used to send EFS Configuration Response.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Assignment is not needed here since err is always gets value.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Channel moves are triggered by changes to the BT_CHANNEL_POLICY
sockopt when an ERTM or streaming-mode channel is connected.
Moves are only started if enable_hs is true.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Do not retransmit previously-sent data when a "receiver ready" s-frame
with the "final" flag is received during a move.
The ERTM state machines will resynchronize at the end of a channel
move, and the state machine needs to avoid state changes during a
move.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When operating over BR/EDR, ERTM accounts for the maximum over-the-air
packet size when setting the PDU size. AMP controllers do not use the
same over-the-air packets, so the PDU size should only be based on the
HCI MTU of the AMP controller.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The L2CAP spec recommends specific retransmit and monitor timeouts for
ERTM channels that are on AMP controllers. These timeouts are
calculated from the AMP controller's best effort flush timeout.
BR/EDR controllers use the default retransmit and monitor timeouts.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Outgoing ERTM data is queued during a channel move. The ERTM state
machine is partially reset at the start of a move, and must be
resynchronized with the remote state machine at the end of the move.
Data is not sent so that there are no state transitions between the
partial reset and the resync.
Streaming mode frames are dropped during a move.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
AMP controllers expect to transmit only "complete" ACL frames. These
frames have both the "start" and "cont" bits set. AMP does not allow
fragmented ACLs.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Several different actions may be taken when an AMP physical link
becomes available. A channel being created on an AMP controller must
continue the connection process. A channel being moved needs to
either send a move request or a move response. A failed physical link
will revert to using a BR/EDR controller if possible.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The move confirm response concludes the channel move command sequence.
Receipt of this command indicates that data may begin to flow again.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The logical link confirm callback is executed when the AMP controller
completes its logical link setup. During a channel move, a newly
formed logical link allows a move responder to send a move channel
response. A move initiator will send a move channel confirm. A
failed logical link will end the channel move and send an appropriate
response or confirm command indicating a failure.
If the channel is being created on an AMP controller, L2CAP
configuration is completed after the logical link is set up.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The move response command includes a result code indicating
"pending", "success", or "failure" status. A pending result is
received when the remote address is still setting up a physical link,
and will be followed by success or failure. On success, logical link
setup will proceed. On failure, the move is stopped. The receiver of
a move channel response must always follow up by sending a move
channel confirm command.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
After sending a move channel response, a move responder waits for a
move channel confirm command. If the received command has a
"confirmed" result the move is proceeding, and "unconfirmed" means the
move has failed and the channel will not change controllers.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Two new states are required to implement channel moves with the ERTM
receive state machine.
The "WAIT_P" state is used by a move responder to wait for a "poll"
flag after a move is completed (success or failure). "WAIT_F" is
similarly used by a move initiator to wait for a "final" flag when the
move is completing. In either state, the reqseq value in the
poll/final frame tells the state machine exactly which frame should be
expected next.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
On receipt of a channel move request, the request must be validated
based on the L2CAP mode, connection state, and controller
capabilities. ERTM channels must have their state machines cleared
and transmission paused while the channel move takes place.
If the channel is being moved to an AMP controller then
an AMP physical link must be prepared. Moving the channel back to
BR/EDR proceeds immediately.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Processing a move channel request involves getting the channel
structure using the destination channel ID. Previous code could only
look up using the source channel ID.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Resolves a conflict resolution issue in "Bluetooth: Fix L2CAP coding
style". The remaining connect and create channel response handler is
renamed to better reflect its use for both response types.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The L2CAP create channel request is very similar to an L2CAP connect
request, but it has an additional parameter for the controller ID. If
the controller id is 0, the channel is set up on the BR/EDR controller
(just like a connect request). Using a valid high speed controller ID
will cause the channel to be initially created on that high speed
controller. While the L2CAP data will be initially routed over the
AMP controller, the L2CAP fixed signaling channel only uses BR/EDR.
When a create channel request is received for a high speed controller,
a pending response is always sent first. After the high speed
physical and logical links are complete a success response will be
sent.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
An L2CAP channel using high speed continues to be associated with a
BR/EDR l2cap_conn, while also tracking an additional hci_conn
(representing a physical link on a high speed controller) and hci_chan
(representing a logical link). There may only be one physical link
between two high speed controllers. Each physical link may contain
several logical links, with each logical link representing a channel
with specific quality of service.
During a channel move, the destination channel id, current move state,
and role (initiator vs. responder) are tracked and used by the channel
move state machine. The ident value associated with a move request
must also be stored in order to use it in later move responses.
The active channel is stored in local_amp_id.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
