When trying to allocate skb for new PDU, l2cap_chan is unlocked so we
can sleep waiting for memory as otherwise there's possible deadlock as
fixed in e454c844. However, in a6a5568c lock was moved from socket
to channel level and it's no longer safe to just unlock and lock again
without checking l2cap_chan state since channel can be disconnected
when lock is not held.

This patch adds missing checks for l2cap_chan state when returning from
call which allocates skb.

Scenario is easily reproducible by running rfcomm-tester in a loop.

BUG: unable to handle kernel NULL pointer dereference at         (null)
IP: [<ffffffffa0442169>] l2cap_do_send+0x29/0x120 [bluetooth]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in:
CPU: 7 PID: 4038 Comm: krfcommd Not tainted 3.14.0-rc2+ #15
Hardware name: Dell Inc. OptiPlex 790/0HY9JP, BIOS A10 11/24/2011
task: ffff8802bdd731c0 ti: ffff8801ec986000 task.ti: ffff8801ec986000
RIP: 0010:[<ffffffffa0442169>]  [<ffffffffa0442169>] l2cap_do_send+0x29/0x120
RSP: 0018:ffff8801ec987ad8  EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8800c5796800 RCX: 0000000000000000
RDX: ffff880410e7a800 RSI: ffff8802b6c1da00 RDI: ffff8800c5796800
RBP: ffff8801ec987af8 R08: 00000000000000c0 R09: 0000000000000300
R10: 000000000000573b R11: 000000000000573a R12: ffff8802b6c1da00
R13: 0000000000000000 R14: ffff8802b6c1da00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000041257c000 CR4: 00000000000407e0
Stack:
 ffff8801ec987d78 ffff8800c5796800 ffff8801ec987d78 0000000000000000
 ffff8801ec987ba8 ffffffffa0449e37 0000000000000004 ffff8801ec987af0
 ffff8801ec987d40 0000000000000282 0000000000000000 ffffffff00000004
Call Trace:
 [<ffffffffa0449e37>] l2cap_chan_send+0xaa7/0x1120 [bluetooth]
 [<ffffffff81770100>] ? _raw_spin_unlock_bh+0x20/0x40
 [<ffffffffa045188b>] l2cap_sock_sendmsg+0xcb/0x110 [bluetooth]
 [<ffffffff81652b0f>] sock_sendmsg+0xaf/0xc0
 [<ffffffff810a8381>] ? update_curr+0x141/0x200
 [<ffffffff810a8961>] ? dequeue_entity+0x181/0x520
 [<ffffffff81652b60>] kernel_sendmsg+0x40/0x60
 [<ffffffffa04a8505>] rfcomm_send_frame+0x45/0x70 [rfcomm]
 [<ffffffff810766f0>] ? internal_add_timer+0x20/0x50
 [<ffffffffa04a8564>] rfcomm_send_cmd+0x34/0x60 [rfcomm]
 [<ffffffffa04a8605>] rfcomm_send_disc+0x75/0xa0 [rfcomm]
 [<ffffffffa04aacec>] rfcomm_run+0x8cc/0x1a30 [rfcomm]
 [<ffffffffa04aa420>] ? rfcomm_check_accept+0xc0/0xc0 [rfcomm]
 [<ffffffff8108e3a9>] kthread+0xc9/0xe0
 [<ffffffff8108e2e0>] ? flush_kthread_worker+0xb0/0xb0
 [<ffffffff817795fc>] ret_from_fork+0x7c/0xb0
 [<ffffffff8108e2e0>] ? flush_kthread_worker+0xb0/0xb0
Code: 00 00 66 66 66 66 90 55 48 89 e5 48 83 ec 20 f6 05 d6 a3 02 00 04
RIP  [<ffffffffa0442169>] l2cap_do_send+0x29/0x120 [bluetooth]
 RSP <ffff8801ec987ad8>
CR2: 0000000000000000
Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

To be friendly to user space and to behave well with controllers that
lack a proper internal power off procedure we should try to clean up as
much state as possible before requesting the HCI driver to power off.

This patch updates the power off procedure that's triggered by
mgmt_set_powered to clean any scan modes, stop LE scanning and
advertising and to disconnect any open connections.

The asynchronous cleanup procedure uses the HCI request framework,
however since HCI_Disconnect is only covered until its Command Status
event we need some extra tracking/waiting of disconnections. This is
done by monitoring when hci_conn_count() indicates that there are no
more connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_ADVERTISING flag in mgmt_advertising()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_CONNECTABLE flag in mgmt_connectable()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) is updated to clear the scan mode we should
not just blindly clear the HCI_DISCOVERABLE flag in mgmt_discoverable()
but first check if there is a pending set_powered operation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Once mgmt_set_powered(off) starts doing disconnections we'll need to
care about any disconnections in mgmt.c and not just those with the
MGMT_CONNECTED flag set. Therefore, move the check into mgmt.c from
hci_event.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We'll soon need to make decisions on toggling the HCI_ADVERTISING flag
based on pending mgmt_set_powered commands. Therefore, move the handling
from hci_event.c into mgmt.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a convenience function to return the number of
connections in the conn_hash list. This will be useful once we update
the power off procedure to disconnect any open connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The RPA expiry timer is only initialized inside mgmt.c when we receive
the first command from user space. This action also involves setting the
HCI_MGMT flag for the first time so that flag acts as a good indicator
of whether the delayed work variable can be touched or not. This patch
fixes hci_dev_do_close to first check the flag.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

A user space that supports the Set Privacy command is also expected to
be able to handle New IRK events. Therefore, set the HCI_RPA_RESOLVING
flag whenever the Set Privacy command is received.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The identity information in debugfs currently do not include the
current in use local RPA. Since the RPA is now stored in the
controller information, include it in the debugfs as well.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The RPA needs to be stored to know which is the current one. Otherwise
it is impossible to ensure that always the correct RPA can be programmed
into the controller when it is needed.

Current code checks if the address in the controller is a RPA, but that
can potentially lead to using a RPA that can not be resolved with the
IRK that has been distributed.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When enabling non-connectable advertising, there is no need to advertise
with a public address or static address. In case LE privacy has not been
enabled a unresolvable private address will be used.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When running active scanning during LE discovery, do not reveal the own
identity to the peer devices. In case LE privacy has been enabled, then
a resolvable private address is used. If the LE privacy option is off,
then use an unresolvable private address.

The public address or static random address is never used in active
scanning anymore. This ensures that scan request are send using a
random address.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When using LE Privacy it is useful to know the local identity address,
identity address type and identity resolving key. For debugging purposes
add these information to debugfs.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Now that the identity address type is always looked up for all
successful connections, the hdev->own_addr_type variable has become
completely unnecessary. Simply remove it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch ensures that conn->src_type contains the same address type as
is used for initiating the connection while the connection attempt is in
progress. Once connected this value will be overwritten with the
identity address type.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds support for handling the Set Privacy mgmt command,
including copying the value to hdev->irk and toggling the HCI_PRIVACY
flag.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a rpa_timeout debugfs entry which can be used to set the
RPA regeneration timeout to something else than the default 15 minutes.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Since we always update the random address before enabling advertising,
scanning and initiating LE connections there is no need to write the
random address add power on.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we start LE scanning we need to update the local random address if
necessary. This patch updates the code to use hci_update_random_address()
for setting the own_address_type scan parameter and updating the local
random address if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we enable advertising we need to update the local random address if
necessary. This patch takes advantage of the hci_update_random_address()
function to set the own_address_type variable and to update the local
random address if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When we initiate LE connections we need to update the local random
address if necessary. This patch updates the LE connection creation
mechanism to use the new hci_update_random_address() function to set the
own_address_type parameter and to update the local random address if
necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a convenience function for updating the local random
address which is needed before advertising, scanning and initiating LE
connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds a timer for updating the local RPA periodically. The
default timeout is set to 15 minutes.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

We need a function in smp.c to generate Resolvable Random Addresses in
order to support privacy. The local RPA will need to be generated before
advertising, scanning or connecting and regenerated at periodic
intervals. This patch adds the necessary function for RPA generation.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The SMP Identity Address Information PDU should contain our Identity
Address. This patch updates the code to copy the correct values from the
hci_conn object.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

To be consistent with the remote address info in hci_conn we want it to
also contain the local identity address information. This patch updates
the code to copy the right values in place whenever an LE connection has
been established.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch makes sure that the Privacy flag is available in the mgmt
supported settings for all LE capable controllers and in the current
settings whenever the HCI_PRIVACY flag is set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch adds basic mgmt defines for enabling privacy. This includes a
new setting flag as well as the Set Privacy command.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

These functions will soon be needed by the RPA regeneration timeout so
move them higher up in mgmt.c to avoid a forward declaration.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This code adds a HCI_PRIVACY flag to track whether Privacy support is
enabled (meaning we have a local IRK) and makes sure the IRK is
distributed during SMP key distribution in case this flag is set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This patch a couple of helper variables to the smp_distribute_keys
function in order to avoid long chains of dereferences and thereby help
readability.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The event opcode for New Identity Resolving Key event is missing from
supported event list. Just add it there.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

We should be iterating hdev->identity_resolving_keys in the
hci_remove_irk() function instead of hdev->long_term_keys. This patch
fixes the issue.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

With the addition of Resolvable Private Address (RPA) resolution
support for Bluetooth Low Energy connections, it makes sense to
increase the minor version of the Bluetooth core module.

The module version is not used anywhere, but it gives a nice extra
hint for debugging purposes.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

For testing purposes it is useful to provide an option to change the
advertising channel map. So add a debugfs option to allow this.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

When binding RFCOMM socket with non-zero channel we're checking if
there is already any other socket which has the same channel number
assigned and then fail. This check does not consider situation where
we have another socket connected to remote device on given channel
number in which case we still should be able to bind local socket.

This patch changes __rfcomm_get_sock_by_addr() to return only sockets
in either BT_BOUND or BT_LISTEN states, also name is updated to better
describe what this function does now.
Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

For Bluetooth controllers with LE support, track the value of the
currently configured random address. It is important to know what
the current random address is to avoid unneeded attempts to set
a new address. This will become important when introducing the
LE privacy support in the future.

In addition expose the current configured random address via
debugfs for debugging purposes.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

The own_address_type debugfs option does not providing enough
flexibity for interacting with the upcoming LE privacy support.

What really is needed is an option to force using the static address
compared to the public address. The new force_static_address debugfs
option does exactly that. In addition it is also only available when
the controller does actually have a public address. For single mode
LE only controllers this option will not be available.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>