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>

This is used to configure APs to not bridge traffic between connected stations.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

cfg80211 is quite strict on allowing authentication and association
commands only in certain states. In order to meet these requirements,
user space applications may need to clear authentication or
association state in some cases. Currently, this can be done with
deauth/disassoc command, but that ends up sending out Deauthentication
or Disassociation frame unnecessarily. Add a new nl80211 attribute to
allow this sending of the frame be skipped, but with all other
deauth/disassoc operations being completed.

Similar state change is also needed for IEEE 802.11r FT protocol in
the FT-over-DS case which does not use Authentication frame exchange
in a transition to another BSS. For this to work with cfg80211, an
authentication entry needs to be created for the target BSS without
sending out an Authentication frame. The nl80211 authentication
command can be used for this purpose, too, with the new attribute to
indicate that the command is only for changing local state. This
enables wpa_supplicant to complete FT-over-DS transition successfully.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

iw dev <devname> station del <MAC address> is quiet useful in mesh mode and should be possible.
Signed-off-by: NMarco Porsch <marco.porsch@siemens.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add support for basic configuration of a connection quality monitoring to the
nl80211 interface, and basic support for notifying about triggered monitoring
events.

Via this interface a user-space connection manager may configure and receive
pre-warning events of deteriorating WLAN connection quality, and start
preparing for roaming in advance, before the connection is already lost.

An example usage of such a trigger is starting scanning for nearby AP's in
an attempt to find one with better connection quality, and associate to it
before the connection characteristics of the existing connection become too bad
or the association is even lost, leading in a prolonged delay in connectivity.

The interface currently supports only RSSI, but it could be later extended
to include other parameters, such as signal-to-noise ratio, if need for that
arises.
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The most needed command from nl80211, which Wireless Extensions had,
is support for power save mode. Add a simple command to make it possible
to enable and disable power save via nl80211.

I was also planning about extending the interface, for example adding the
timeout value, but after thinking more about this I decided not to do it.
Basically there were three reasons:

Firstly, the parameters for power save are very much hardware dependent.
Trying to find a unified interface which would work with all hardware, and
still make sense to users, will be very difficult.

Secondly, IEEE 802.11 power save implementation in Linux is still in state
of flux. We have a long way to still to go and there is no way to predict
what kind of implementation we will have after few years. And because we
need to support nl80211 interface a long time, practically forever, adding
now parameters to nl80211 might create maintenance problems later on.

Third issue are the users. Power save parameters are mostly used for
debugging, so debugfs is better, more flexible, interface for this.
For example, wpa_supplicant currently doesn't configure anything related
to power save mode. It's better to strive that kernel can automatically
optimise the power save parameters, like with help of pm qos network
and other traffic parameters.

Later on, when we have better understanding of power save, we can extend
this command with more features, if there's a need for that.
Signed-off-by: NKalle Valo <kalle.valo@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Make remaining netlink policies as const.
Fixup coding style where needed.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This implements a new command to register for action frames
that userspace wants to handle instead of the in-kernel
rejection. It is then responsible for rejecting ones that
it decided not to handle. There is no unregistration, but
the socket can be closed for that.

Frames that are not registered for will not be forwarded
to userspace and will be rejected by the kernel, the
cfg80211 API helps implementing that.

Additionally, this patch adds a new command that allows
doing action frame transmission from userspace. It can be
used either to exchange action frames on the current
operational channel (e.g., with the AP with which we are
currently associated) or to exchange off-channel Public
Action frames with the remain-on-channel command.
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>

As discussed in linux-wireless mailing list, adding and removing
stations for mesh topologies is not necessary. Since doing it triggers
bugs, the sugestion was to simply disable it.

Tested using a custom iw command "station new". Works only after using
hostapd. "station del" command also works.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Simon Raffeiner <sturmflut@lieberbiber.de>
Cc: Andrey Yurovsky <andrey@cozybit.com>
Cc: Javier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

nl80211_associate() was rejecting (re)association attempts with EBUSY
in some cases where we are currently associated with an AP that uses
different channel from the destination AP. Fix this by passing the
current wdev to rdev_fixed_channel() in the same way that was already
done for join-IBSS and connect commands. This allows the fixedchan
check to skipped for the current wdev and allows the reassociation to
proceed.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Store information elements from Beacon and Probe Response frames in
separate buffers to allow both sets to be made available through
nl80211. This allows user space applications to get access to IEs from
Beacon frames even if we have received Probe Response frames from the
BSS. Previously, the IEs from Probe Response frames would have
overridden the IEs from Beacon frames.

This feature is of somewhat limited use since most protocols include
the same (or extended) information in Probe Response frames. However,
there are couple of exceptions where the IEs from Beacon frames could
be of some use: TIM IE is only included in Beacon frames (and it would
be needed to figure out the DTIM period used in the BSS) and at least
some implementations of Wireless Provisioning Services seem to include
the full IE only in Beacon frames).

The new BSS attribute for scan results is added to allow both the IE
sets to be delivered. This is done in a way that maintains the
previously used behavior for applications that are not aware of the
new NL80211_BSS_BEACON_IES attribute.
Signed-off-by: NJouni Malinen <j@w1.fi>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add a new NL80211_CMD_SET_TX_BITRATE_MASK command and related
attributes to provide support for setting TX rate mask for rate
control. This uses the existing cfg80211 set_bitrate_mask operation
that was previously used only with WEXT compat code (SIOCSIWRATE). The
nl80211 command allows more generic configuration of allowed rates as
a mask instead of fixed/max rate.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The new attribute NL80211_ATTR_WIPHY_COVERAGE_CLASS sets IEEE 802.11
Coverage Class, which depends on maximum distance of nodes in a
wireless network. It's required for long distance links (more than a few
hundred meters).

The attribute is now ignored by two non-mac80211 drivers, rndis and
iwmc3200wifi, together with WIPHY_PARAM_RETRY_SHORT and
WIPHY_PARAM_RETRY_LONG. If it turns out to be a problem, we could split
set_wiphy_params callback or add new capability bits.
Signed-off-by: NLukas Turek <8an@praha12.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When, for instance, a new IBSS peer is found, userspace
wants to be notified. Add events for all new stations
that mac80211 learns about.
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>

This is no longer needed with the availability of
CONFIG_CFG80211_INTERNAL_REGDB.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Previously, cfg80211 had reported "0" for MCS (i.e. 802.11n) bitrates
through the wireless extensions interface.  However, nl80211 was
converting MCS rates into a reasonable bitrate number.  This patch moves
the nl80211 code to cfg80211 where it is now shared between both the
nl80211 interface and the wireless extensions interface.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This is an interface to set, delete and flush PMKIDs through nl80211.
Main users would be fullmac devices which firmwares are capable of
generating the RSN IEs for the re-association requests, e.g. iwmc3200wifi.
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

A number of people have tried to add a wireless interface
(in managed mode) to a bridge and then complained that it
doesn't work. It cannot work, however, because in 802.11
networks all packets need to be acknowledged and as such
need to be sent to the right address. Promiscuous doesn't
help here. The wireless address format used for these
links has only space for three addresses, the
 * transmitter, which must be equal to the sender (origin)
 * receiver (on the wireless medium), which is the AP in
   the case of managed mode
 * the recipient (destination), which is on the APs local
   network segment

In an IBSS, it is similar, but the receiver and recipient
must match and the third address is used as the BSSID.

To avoid such mistakes in the future, disallow adding a
wireless interface to a bridge.

Felix has recently added a four-address mode to the AP
and client side that can be used (after negotiating that
it is possible, which must happen out-of-band by setting
up both sides) for bridging, so allow that case.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It's very likely that not many devices will support
four-address mode in station or AP mode so introduce
capability bits for both modes, set them in mac80211
and check them when userspace tries to use the mode.
Also, keep track of 4addr in cfg80211 (wireless_dev)
and not in mac80211 any more. mac80211 can also be
improved for the VLAN case by not looking at the
4addr flag but maintaining the station pointer for
it correctly. However, keep track of use_4addr for
station mode in mac80211 to avoid all the derefs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We've accumulated a number of options for wiphys
which make more sense as flags as we keep adding
more. Convert the existing ones.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch implements the NL80211_CMD_GET_SURVEY command and an get_survey()
ops that a driver can implement. The goal of this command is to allow a
drivers to report channel survey data (e.g. channel noise, channel
occupation).

For now, only the mechanism to report back channel noise has been
implemented.

In future, there will either be a survey-trigger command --- or the existing
scan-trigger command will be enhanced. This will allow user-space to
request survey for arbitrary channels.

Note: any driver that cannot report channel noise should not report
any value at all, e.g. made-up -92 dBm.
Signed-off-by: NHolger Schurig <holgerschurig@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

... which get's rid of three indentical cut-n-paste sections.
Signed-off-by: NHolger Schurig <holgerschurig@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NRui Paulo <rpaulo@gmail.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Reviewed-by: NAndrey Yurovsky <andrey@cozybit.com>
Tested-by: NBrian Cavagnolo <brian@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Resulting object files have the same MD5 as before.
Signed-off-by: NRui Paulo <rpaulo@gmail.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Reviewed-by: NAndrey Yurovsky <andrey@cozybit.com>
Tested-by: NBrian Cavagnolo <brian@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently it is possible to request a scan on only
disabled channels, which could be problematic for
some drivers. Reject such scans, and also ignore
disabled channels that are given. This resuls in
the scan begin/end event only including channels
that are actually used.

This makes the mac80211 check for disabled channels
superfluous. At the same time, remove the no-IBSS
check from mac80211 -- nothing says that we should
not find any networks on channels that cannot be
used for an IBSS, even when operating in IBSS mode.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The error unwinding code in set_netns has a bug
that will make it run into a BUG_ON if passed a
bad wiphy index, fix by not trying to unlock a
wiphy that doesn't exist.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Refactor wext to
 * split out iwpriv handling
 * split out iwspy handling
 * split out procfs support
 * allow cfg80211 to have wireless extensions compat code
   w/o CONFIG_WIRELESS_EXT

After this, drivers need to
 - select WIRELESS_EXT	- for wext support
 - select WEXT_PRIV	- for iwpriv support
 - select WEXT_SPY	- for iwspy support

except cfg80211 -- which gets new hooks in wext-core.c
and can then get wext handlers without CONFIG_WIRELESS_EXT.

Wireless extensions procfs support is auto-selected
based on PROC_FS and anything that requires the wext core
(i.e. WIRELESS_EXT or CFG80211_WEXT).
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Linux keeps scan results up to 15 seconds. This can be a problem for fast
moving clients: they get back stale data. But if the kernel reports the age
of the BSS items, then user-space can simply weed out old entries by itself.
Signed-off-by: NHolger Schurig <hs4233@mail.mn-solutions.de>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Jump to out_err when the iftype is not supported.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the interface type changes while connected, and the
driver does not require the interface to be down for a
type change, it is currently possible to get very strange
results unless the driver takes special care, which it
shouldn't have to.

To fix this, take care to disconnect/leave IBSS when
changing the interface type -- even if the driver may fail
the call. Also process all events that may be pending to
avoid running into a situation where an event is reported
but only processed after the type has already changed,
which would lead to missing events and warnings.

A side effect of this is that you will have disconnected
or left the IBSS even if the mode change ultimately fails,
but since the intention was to change it and thus leave or
disconnect, this is not a problem.
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>

The memory layout for scan requests was rather wrong,
we put the scan SSIDs before the channels which could
lead to the channel pointers being unaligned in memory.
It turns out that using a pointer to the channel array
isn't necessary anyway since we can embed a zero-length
array into the struct.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.

This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.

The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
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>

Until now we implemented iwfreq for managed mode, we
needed to keep the implementations separate, but now
that we have all versions implemented we can combine
them and export just one handler.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Jouni and Maxim reported an oops when using wpa_supplicant -Dnl80211,
which seems to be due to random data being contained in the crypto
settings for the assoc() command. This seems to be due to the missing
memset here, so add it -- it's certainly missing but I'm not 100%
certain that it will fix the problem.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Luis reported this lockdep complaint, that he had also
reported earlier but when trying to analyse I had been
locking at the wrong code, and never saw the problem:

(slightly abridged)
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.31-rc4-wl #6
-------------------------------------------------------
wpa_supplicant/3799 is trying to acquire lock:
 (cfg80211_mutex){+.+.+.}, at: [<ffffffffa009246a>] cfg80211_get_dev_from_ifindex+0x1a/0x90 [cfg80211]

but task is already holding lock:
 (rtnl_mutex){+.+.+.}, at: [<ffffffff81400ff2>] rtnl_lock+0x12/0x20

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.+.}:
       [<ffffffff810857b6>] __lock_acquire+0xd76/0x12b0
       [<ffffffff81085dd3>] lock_acquire+0xe3/0x120
       [<ffffffff814ee7a4>] mutex_lock_nested+0x44/0x350
       [<ffffffff81400ff2>] rtnl_lock+0x12/0x20
       [<ffffffffa009f6a5>] nl80211_send_reg_change_event+0x1f5/0x2a0 [cfg80211]
       [<ffffffffa009529e>] set_regdom+0x28e/0x4c0 [cfg80211]

-> #0 (cfg80211_mutex){+.+.+.}:
       [<ffffffff8108587b>] __lock_acquire+0xe3b/0x12b0
       [<ffffffff81085dd3>] lock_acquire+0xe3/0x120
       [<ffffffff814ee7a4>] mutex_lock_nested+0x44/0x350
       [<ffffffffa009246a>] cfg80211_get_dev_from_ifindex+0x1a/0x90 [cfg80211]
       [<ffffffffa009813f>] get_rdev_dev_by_info_ifindex+0x6f/0xa0 [cfg80211]
       [<ffffffffa009b12b>] nl80211_set_interface+0x3b/0x260 [cfg80211]

When looking at the correct code, the problem is quite
obvious. I'm not entirely sure which code paths lead
here, so until I can analyse it better let's just use
RCU to avoid the problem.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>