If the remote L2CAP server uses authentication pending stage and
encryption is enabled it can happen that a L2CAP connection request is
sent twice due to a race condition in the connection state machine.

When the remote side indicates any kind of connection pending, then
track this state and skip sending of L2CAP commands for this period.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When two L2CAP connections are requested quickly after the ACL link has
been established there exists a window for a race condition where a
connection request is sent before the information response has been
received. Any connection request should only be sent after an exchange
of the extended features mask has been finished.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Change the L2CAP internals to use the new security levels and remove
the link mode details.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In case the remote entity tries to negogiate retransmission or flow
control mode, reject it and fall back to basic mode.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth 1.2 specification introduced a specific features mask
value to interoperate with newer versions of the specification. So far
this piece of information was never needed, but future extensions will
rely on it. This patch adds a generic way to retrieve this information
only once per connection setup.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

After the change to the L2CAP configuration parameter handling the
global conf_mtu variable is no longer needed and so remove it.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

no code changes, just documenting existing types
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The L2CAP configuration parameter handling was missing the support
for rejecting unknown options. The capability to reject unknown
options is mandatory since the Bluetooth 1.2 specification. This
patch implements its and also simplifies the parameter parsing.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!