Some drivers might support 80 or 160 MHz only on some
channels for whatever reason, so allow them to disable
these channel widths. Also maintain the new flags when
regulatory bandwidth limitations would disable these
wide channels.
Reviewed-by: NLuis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add new NL80211_CMD_RADAR_DETECT, which starts the Channel
Availability Check (CAC). This command will also notify the
usermode about events (CAC finished, CAC aborted, radar
detected, NOP finished).
Once radar detection has started it should continuously
monitor for radars as long as the channel is active.

This patch enables DFS for AP mode in nl80211/cfg80211.

Based on original patch by Victor Goldenshtein <victorg@ti.com>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
[remove WIPHY_FLAG_HAS_RADAR_DETECT again -- my mistake]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In that case, it's really a 160 MHz channel, so disallow
this configuration.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For channels wider than 20 MHz OFDM will be used, so when
checking whether or not a channel is usable, check for the
no-OFDM flag if the channel is wider than 20 MHz.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some of the chandef checking that we do in cfg80211
to check if a channel is supported or not is also
needed in mac80211, so rework that a bit and export
the functions that are needed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Change nl80211 to support specifying a VHT (or HT)
using the control channel frequency (as before) and
new attributes for the channel width and first and
second center frequency. The old channel type is of
course still supported for HT.

Also change the cfg80211 channel definition struct
to support these by adding the relevant fields to
it (and removing the _type field.)

This also adds new helper functions:
 - cfg80211_chandef_create to create a channel def
   struct given the control channel and channel type,
 - cfg80211_chandef_identical to check if two channel
   definitions are identical
 - cfg80211_chandef_compatible to check if the given
   channel definitions are compatible, and return the
   wider of the two

This isn't entirely complete, but that doesn't matter
until we have a driver using it. In particular, it's
missing
 - regulatory checks on the usable bandwidth (if that
   even makes sense)
 - regulatory TX power (database can't deal with it)
 - a proper channel compatibility calculation for the
   new channel types
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of passing a channel pointer and channel type
to all functions and driver methods, pass a new channel
definition struct. Right now, this struct contains just
the control channel and channel type, but for VHT this
will change.

Also, add a small inline cfg80211_get_chandef_type() so
that drivers don't need to use the _type field of the
new structure all the time, which will change.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Also add tracing to the API functions that drivers
(and mac80211) can call in cfg80211.
Signed-off-by: NBeni Lev <beni.lev@intel.com>
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This will allow adding central tracing like in mac80211.
Signed-off-by: NHila Gonen <hila.gonen@intel.com>
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In order to support using a different MAC address
for the P2P Device address we must first have a
P2P Device abstraction that can be assigned a MAC
address.

This abstraction will also be useful to support
offloading P2P operations to the device, e.g.
periodic listen for discoverability.

Currently, the driver is responsible for assigning
a MAC address to the P2P Device, but this could be
changed by allowing a MAC address to be given to
the NEW_INTERFACE command.

As it has no associated netdev, a P2P Device can
only be identified by its wdev identifier but the
previous patches allowed using the wdev identifier
in various APIs, e.g. remain-on-channel.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Revert commit b78e8cea
("cfg80211: track monitor channel") and remove the
set_monitor_enabled() callback.

Due to the tracking happening in NETDEV_PRE_UP, it had
introduced bugs because the monitor interface callback
would be called before the device was started. It looks
like there's no way to fix this, and using NETDEV_PRE_UP
is broken anyway (since there's no NETDEV_UP_FAIL), so
remove all that code, track interfaces in NETDEV_UP and
also stop tracking the monitor channel in cfg80211.

This mostly reverts to before the tracking, except that
we keep the interface count tracking so that setting the
monitor channel can be rejected properly.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Without this change, running AP + station on the same wiphy
does not work since the commit "cfg80211: add channel checking
for iface combinations". The stopped AP prevents the client
from connecting to an AP on a different channel.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
[line-break commit message to < 72 chars]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

To call cfg80211_get_chan_state() we need to lock
the wdev, so we need to lock the wdev_iter mutex
in cfg80211_can_use_iftype_chan(). This needs to
use nested locking for lockdep.

Also, cfg80211_get_chan_state() doesn't actually
use the rdev, so remove that completely including
the lock assertion that isn't needed.
Reported-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Make it even more obvious we support single
monitor channel. This will allow us to remove
.get_channel.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Having .set_monitor_channel work with non-monitor
interfaces running would make interface
combinations accounting ambiguous.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Helper function for finding out which channel is
used by a given interface.

An exclusive channel can be used only by a single
interface. This is mainly for non-fixed channel
IBSS handling.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Now that we've removed all uses of the set_channel
API except for the monitor channel and in libertas,
clarify this. Split the libertas mesh use into a
new libertas_set_mesh_channel() operation, just to
keep backward compatibility, and rename the normal
set_channel() to set_monitor_channel().

Also describe the desired set_monitor_channel()
semantics more clearly.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Change cfg80211_can_beacon_sec_chan() to return true
if there is no secondary channel to simplify all the
current users of it. They all check the channel type
before calling the function because it returns false
if there's no secondary channel.

Also actually document the return value.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It should return bool, not int. The function even
does return true/false.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Prepare cfg80211 for IBSS HT:
 * extend cfg80211 ibss struct with channel_type
 * Check if extension channel can be used
 * Export can_beacon_sec_chan for use in mac80211 (will be called
   from ibss.c later).
Signed-off-by: NAlexander Simon <an.alexsimon@googlemail.com>
[siwu@hrz.tu-chemnitz.de: Updates]
* fix cfg80211_can_beacon_ext_chan comment
* remove implicit channel_type enum assumptions
* remove radar channel flags check
* add HT IBSS feature flag
* reword commit message
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This follows wireless-testing 9236d838
("cfg80211: fix extension channel checks to initiate communication") and
fixes accidental case fall-through. Without this fix, HT40 is entirely
blocked.
Signed-off-by: NMark Mentovai <mark@moxienet.com>
Cc: stable@kernel.org
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When operating in a mode that initiates communication and using
HT40 we should fail if we cannot use both primary and secondary
channels to initiate communication. Our current ht40 allowmap
only covers STA mode of operation, for beaconing modes we need
a check on the fly as the mode of operation is dynamic and
there other flags other than disable which we should read
to check if we can initiate communication.

Do not allow for initiating communication if our secondary HT40
channel has is either disabled, has a passive scan flag, a
no-ibss flag or is a radar channel. Userspace now has similar
checks but this is also needed in-kernel.
Reported-by: NJouni Malinen <jouni.malinen@atheros.com>
Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Don't refuse HT20 channels on devices that don't support HT40.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since wdev can be NULL, check it before dereferencing it
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently (all tested with hwsim) you can do stupid
things like setting up an AP on a certain channel,
then adding another virtual interface and making
that associate on another channel -- this will make
the beaconing to move channel but obviously without
the necessary IEs data update.

In order to improve this situation, first make the
configuration APIs (cfg80211 and nl80211) aware of
multi-channel operation -- we'll eventually need
that in the future anyway. There's one userland API
change and one API addition. The API change is that
now SET_WIPHY must be called with virtual interface
index rather than only wiphy index in order to take
effect for that interface -- luckily all current
users (hostapd) do that. For monitor interfaces, the
old setting is preserved, but monitors are always
slaved to other devices anyway so no guarantees.

The second userland API change is the introduction
of a per virtual interface SET_CHANNEL command, that
hostapd should use going forward to make it easier
to understand what's going on (it can automatically
detect a kernel with this command).

Other than mac80211, no existing cfg80211 drivers
are affected by this change because they only allow
a single virtual interface.

mac80211, however, now needs to be aware that the
channel settings are per interface now, and needs
to disallow (for now) real multi-channel operation,
which is another important part of this patch.

One of the immediate benefits is that you can now
start hostapd to operate on a hardware that already
has a connection on another virtual interface, as
long as you specify the same channel.

Note that two things are left unhandled (this is an
improvement -- not a complete fix):

 * different HT/no-HT modes

   currently you could start an HT AP and then
   connect to a non-HT network on the same channel
   which would configure the hardware for no HT;
   that can be fixed fairly easily

 * CSA

   An AP we're connected to on a virtual interface
   might indicate switching channels, and in that
   case we would follow it, regardless of how many
   other interfaces are operating; this requires
   more effort to fix but is pretty rare after all
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add new commands for requesting the driver to remain awake
on a specified channel for the specified amount of time
(and another command to cancel such an operation). This
can be used to implement userspace-controlled off-channel
operations, like Public Action frame exchange on another
channel than the operation channel.

The off-channel operation should behave similarly to scan,
i.e. the local station (if associated) moves into power
save mode to request the AP to buffer frames for it and
then moves to the other channel to allow the off-channel
operation to be completed. The duration parameter can be
used to request enough time to receive a response from
the target station.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

"cfg80211: validate channel settings across interfaces"
contained a locking bug -- in the managed-mode SIWFREQ
call it would end up running into a lock recursion.

This fixes it by not checking that particular interface
for a channel that it needs to stay on, which is as it
should be as that's the interface we're setting the
channel for.
Reported-by: NReinette Chatre <reinette.chatre@intel.com>
Reported-by: NKalle Valo <kalle.valo@iki.fi>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Tested-by: NKalle Valo <kalle.valo@iki.fi>
Tested-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently, there's a problem that affects regulatory
enforcement and connection stability, in that it is
possible to switch the channel while connected to a
network or joined to an IBSS.

The problem comes from the fact that we only validate
the channel against the current interface's type, not
against any other interface. Thus, you have any type
of interface up, additionally bring up a monitor mode
interface and switch the channel on the monitor. This
will obviously also switch the channel on the other
interface.

The problem now is that if you do that while sending
beacons for IBSS mode, you can switch to a disabled
channel or a channel that doesn't allow beaconing.
Combined with a managed mode interface connected to
an AP instead of an IBSS interface, you can easily
break the connection that way.

To fix this, this patch validates any channel change
with all available interfaces, and disallows such
changes on secondary interfaces if another interface
is connected to an AP or joined to an IBSS.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>