This adds the basic constants required to add support for L2CAP Enhanced
Retransmission feature.

Based on a patch from Nathan Holstein <nathan@lampreynetworks.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch fixes the errors without changing the l2cap.o binary:

 text    data     bss     dec     hex filename
18059     568       0   18627    48c3 l2cap.o.after
18059     568       0   18627    48c3 l2cap.o.before
Signed-off-by: NGustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The initial value of err is not used until it is set to -ENOMEM. So just
remove the initialization completely.

Based on a patch from Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Using the L2CAP_CONF_HINT macro is easier to understand than using a
hardcoded 0x80 value.
Signed-off-by: NGustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Use macros instead of hardcoded numbers to make the L2CAP source code
more readable.
Signed-off-by: NGustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Remove some pointless conditionals before kfree_skb().
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Userspace pairing code can be simplified if it doesn't have to fall
back to using L2CAP_LM in the case of L2CAP raw sockets. This patch
allows the BT_SECURITY socket option to be used for these sockets.
Signed-off-by: NJohan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In the future the L2CAP layer will have full support for fixed channels
and right now it already can export the channel assignment, but for the
functions bind() and connect() the usage of only CID 0 is allowed. This
allows an easy detection if the kernel supports fixed channels or not,
because otherwise it would impossible for application to tell.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The L2CAP layer can trigger the authentication via an ACL connection or
later on to increase the security level. When increasing the security
level it didn't use the same authentication requirements when triggering
a new ACL connection. Make sure that exactly the same authentication
requirements are used. The only exception here are the L2CAP raw sockets
which are only used for dedicated bonding.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Some of the qualification tests demand that in case of failures in L2CAP
the HCI disconnect should indicate a reason why L2CAP fails. This is a
bluntly layer violation since multiple L2CAP connections could be using
the same ACL and thus forcing a disconnect reason is not a good idea.

To comply with the Bluetooth test specification, the disconnect reason
is now stored in the L2CAP connection structure and every time a new
L2CAP channel is added it will set back to its default. So only in the
case where the L2CAP channel with the disconnect reason is really the
last one, it will propagated to the HCI layer.

The HCI layer has been extended with a disconnect indication that allows
it to ask upper layers for a disconnect reason. The upper layer must not
support this callback and in that case it will nicely default to the
existing behavior. If an upper layer like L2CAP can provide a disconnect
reason that one will be used to disconnect the ACL or SCO link.

No modification to the ACL disconnect timeout have been made. So in case
of Linux to Linux connection the initiator will disconnect the ACL link
before the acceptor side can signal the specific disconnect reason. That
is perfectly fine since Linux doesn't make use of this value anyway. The
L2CAP layer has a perfect valid error code for rejecting connection due
to a security violation. It is unclear why the Bluetooth specification
insists on having specific HCI disconnect reason.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In preparation for L2CAP fixed channel support, the CID value of a
L2CAP connection needs to be accessible via the socket interface. The
CID is the connection identifier and exists as source and destination
value. So extend the L2CAP socket address structure with this field and
change getsockname() and getpeername() to fill it in.

The bind() and connect() functions have been modified to handle L2CAP
socket address structures of variable sizes. This makes them future
proof if additional fields need to be added.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If the extended features mask indicates support for fixed channels,
request the list of available fixed channels. This also enables the
fixed channel features bit so remote implementations can request
information about it. Currently only the signal channel will be
listed.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The recommendation for the L2CAP PSM 1 (SDP) is to not use any kind
of authentication or encryption. So don't trigger authentication
for incoming and outgoing SDP connections.

For L2CAP PSM 3 (RFCOMM) there is no clear requirement, but with
Bluetooth 2.1 the initiator is required to enable authentication
and encryption first and this gets enforced. So there is no need
to trigger an additional authentication step. The RFCOMM service
security will make sure that a secure enough link key is present.

When the encryption gets enabled after the SDP connection setup,
then switch the security level from SDP to low security.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

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>

When receiving incoming connection to specific services, always use
general bonding. This ensures that the link key gets stored and can be
used for further authentications.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For L2CAP sockets with medium and high security requirement a missing
encryption will enforce the closing of the link. For the L2CAP raw
sockets this is not needed, so skip that check.

This fixes a crash when pairing Bluetooth 2.0 (and earlier) devices
since the L2CAP state machine got confused and then locked up the whole
system.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With the support for the enhanced security model and the support for
deferring connection setup, it is a good idea to increase various
version numbers.

This is purely cosmetic and has no effect on the behavior, but can
be really helpful when debugging problems in different kernel versions.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The new socket options should only be evaluated for SOL_BLUETOOTH level
and not for every other level. Previously this causes some minor issues
when detecting if a kernel with certain features is available.

Also restrict BT_SECURITY to SOCK_SEQPACKET for L2CAP and SOCK_STREAM for
the RFCOMM protocol.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For L2CAP connections with high security setting, the link will be
immediately dropped when the encryption gets disabled. For L2CAP
connections with medium security there will be grace period where
the remote device has the chance to re-enable encryption. If it
doesn't happen then the link will also be disconnected.

The requirement for the grace period with medium security comes from
Bluetooth 2.0 and earlier devices that require role switching.
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>

The current security model is based around the flags AUTH, ENCRYPT and
SECURE. Starting with support for the Bluetooth 2.1 specification this is
no longer sufficient. The different security levels are now defined as
SDP, LOW, MEDIUM and SECURE.

Previously it was possible to set each security independently, but this
actually doesn't make a lot of sense. For Bluetooth the encryption depends
on a previous successful authentication. Also you can only update your
existing link key if you successfully created at least one before. And of
course the update of link keys without having proper encryption in place
is a security issue.

The new security levels from the Bluetooth 2.1 specification are now
used internally. All old settings are mapped to the new values and this
way it ensures that old applications still work. The only limitation
is that it is no longer possible to set authentication without also
enabling encryption. No application should have done this anyway since
this is actually a security issue. Without encryption the integrity of
the authentication can't be guaranteed.

As default for a new L2CAP or RFCOMM connection, the LOW security level
is used. The only exception here are the service discovery sessions on
PSM 1 where SDP level is used. To have similar security strength as with
a Bluetooth 2.0 and before combination key, the MEDIUM level should be
used. This is according to the Bluetooth specification. The MEDIUM level
will not require any kind of man-in-the-middle (MITM) protection. Only
the HIGH security level will require this.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In order to decide if listening L2CAP sockets should be accept()ed
the BD_ADDR of the remote device needs to be known. This patch adds
a socket option which defines a timeout for deferring the actual
connection setup.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The socket option levels SOL_L2CAP, SOL_RFOMM and SOL_SCO are currently
in use by various Bluetooth applications. Going forward the common
option level SOL_BLUETOOTH should be used. This patch prepares the clean
split of the old and new option levels while keeping everything backward
compatibility.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With the introduction of CONFIG_DYNAMIC_PRINTK_DEBUG it is possible to
allow debugging without having to recompile the kernel. This patch turns
all BT_DBG() calls into pr_debug() to support dynamic debug messages.

As a side effect all CONFIG_BT_*_DEBUG statements are now removed and
some broken debug entries have been fixed.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Security Mode 4 of the Bluetooth 2.1 specification has strict
authentication and encryption requirements. It is the initiators job
to create a secure ACL link. However in case of malicious devices, the
acceptor has to make sure that the ACL is encrypted before allowing
any kind of L2CAP connection. The only exception here is the PSM 1 for
the service discovery protocol, because that is allowed to run on an
insecure ACL link.

Previously it was enough to reject a L2CAP connection during the
connection setup phase, but with Bluetooth 2.1 it is forbidden to
do any L2CAP protocol exchange on an insecure link (except SDP).

The new hci_conn_check_link_mode() function can be used to check the
integrity of an ACL link. This functions also takes care of the cases
where Security Mode 4 is disabled or one of the devices is based on
an older specification.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With the introduction of Security Mode 4 and Simple Pairing from the
Bluetooth 2.1 specification it became mandatory that the initiator
requires authentication and encryption before any L2CAP channel can
be established. The only exception here is PSM 1 for the service
discovery protocol (SDP). It is meant to be used without any encryption
since it contains only public information. This is how Bluetooth 2.0
and before handle connections on PSM 1.

For Bluetooth 2.1 devices the pairing procedure differentiates between
no bonding, general bonding and dedicated bonding. The L2CAP layer
wrongly uses always general bonding when creating new connections, but it
should not do this for SDP connections. In this case the authentication
requirement should be no bonding and the just-works model should be used,
but in case of non-SDP connection it is required to use general bonding.

If the new connection requires man-in-the-middle (MITM) protection, it
also first wrongly creates an unauthenticated link key and then later on
requests an upgrade to an authenticated link key to provide full MITM
protection. With Simple Pairing the link key generation is an expensive
operation (compared to Bluetooth 2.0 and before) and doing this twice
during a connection setup causes a noticeable delay when establishing
a new connection. This should be avoided to not regress from the expected
Bluetooth 2.0 connection times. The authentication requirements are known
up-front and so enforce them.

To fulfill these requirements the hci_connect() function has been extended
with an authentication requirement parameter that will be stored inside
the connection information and can be retrieved by userspace at any
time. This allows the correct IO capabilities exchange and results in
the expected behavior.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth entries for the MAINTAINERS file are a little bit too
much. Consolidate them into two entries. One for Bluetooth drivers and
another one for the Bluetooth subsystem.

Also the MODULE_AUTHOR should indicate the current maintainer of the
module and actually not the original author. Fix all Bluetooth modules
to provide current maintainer information.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When requested the L2CAP layer will now enforce authentication and
encryption on outgoing connections. The usefulness of this feature
is kinda limited since it will not allow proper connection ownership
tracking until the authentication procedure has been finished. This
is a limitation of Bluetooth 2.0 and before and can only be fixed by
using Simple Pairing.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Enable the common timestamp functionality that the network subsystem
provides for L2CAP, RFCOMM and SCO sockets. It is possible to either
use SO_TIMESTAMP or the IOCTLs to retrieve the timestamp of the
current packet.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With the Simple Pairing support, the authentication requirements are
an explicit setting during the bonding process. Track and enforce the
requirements and allow higher layers like L2CAP and RFCOMM to increase
them if needed.

This patch introduces a new IOCTL that allows to query the current
authentication requirements. It is also possible to detect Simple
Pairing support in the kernel this way.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Bluetooth specification allows to enable or disable the encryption
of an ACL link at any time by either the peer or the remote device. If
a L2CAP or RFCOMM connection requested an encrypted link, they will now
disconnect that link if the encryption gets disabled. Higher protocols
that don't care about encryption (like SDP) are not affected.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Getting the remote L2CAP features mask is really important, but doing
this as less intrusive as possible is tricky. To play nice with older
systems and Bluetooth qualification testing, the features mask is now
only retrieved in two specific cases and only once per lifetime of an
ACL link.

When trying to establish a L2CAP connection and the remote features mask
is unknown, the L2CAP information request is sent when the ACL link goes
into connected state. This applies only to outgoing connections and also
only for the connection oriented channels.

The second case is when a connection request has been received. In this
case a connection response with the result pending and the information
request will be send. After receiving an information response or if the
timeout gets triggered, the normal connection setup process with security
setup will be initiated.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The older RW_LOCK_UNLOCKED macros defeat lockdep state tracing so
replace them with the newer __RW_LOCK_UNLOCKED macros.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

When the l2cap info_timer is active the info_state will be set to
L2CAP_INFO_FEAT_MASK_REQ_SENT, and it will be unset after the timer is
deleted or timeout triggered.

Here in l2cap_conn_del only call del_timer_sync when the info_state is
set to L2CAP_INFO_FEAT_MASK_REQ_SENT.
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Delete a possibly armed timer before kfree'ing the connection object.

Solves: http://lkml.org/lkml/2008/2/15/514Reported-by: NQuel Qun <kelk1@comcast.net>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many-many code in the kernel initialized the timer->function
and  timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Finally, the zero_it argument can be completely removed from
the callers and from the function prototype.

Besides, fix the checkpatch.pl warnings about using the
assignments inside if-s.

This patch is rather big, and it is a part of the previous one.
I splitted it wishing to make the patches more readable. Hope 
this particular split helped.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>