wifi: mac80211: refactor STA CSA parsing flows

The new Wi-Fi Standard (IEEE Std 802.11-2020 9.4.2.160) specifies that
the Wide Bandwidth Channel Switch (WBCS) Element subfields have the same
definitions as VHT operation information if the operating band is not
S1G.

The problem comes when the BSS is in 6 GHz band, the STA parses the WBCS
Element by ieee80211_chandef_vht_oper(), which checks the capabilities for
HT/VHT mode, not HE/EHT mode.

This patch refactors STA CSA parsing flow so that the corresponding
capabilities can be checked. Also, it adds the way to use op_class in ECSA
Element to build a new chandef.

In summary, the new steps for STA to handle CSA event are:
1. build the new chandef from one of the CSA-related (Sub)Elements in
following order,
- Bandwidth Indication (Sub)Element
- Wide Bandwidth Channel Switch (Sub)Element
- Operating class in Extended Channel Switch Announcement Element
- Channel Switch Announcement Element
2. convert the new chandef into operation information according to the
operating band in order to check if the new chandef fits STA's
capabilities.
3. downgrade the bandwidth until current bandwidth is not disabled.

Co-developed-by: Money Wang <money.wang@mediatek.com>
Signed-off-by: Michael-CY Lee <michael-cy.lee@mediatek.com>
Link: https://msgid.link/20231222010914.6521-3-michael-cy.lee@mediatek.com
[rebase on top of the changes with struct ieee80211_conn_settings,
prefer leXY_encode_bits()]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: introduce 'channel request'

For channel contexts, mac80211 currently uses the cfg80211
chandef struct (control channel, center freq(s), width) to
define towards drivers and internally how these behave. In
fact, there are _two_ such structs used, where the min_def
can reduce bandwidth according to the stations connected.

Unfortunately, with EHT this is longer be sufficient, at
least not for all hardware. EHT requires that non-AP STAs
that are connected to an AP with a lower bandwidth than it
(the AP) advertises (e.g. 160 MHz STA connected to 320 MHz
AP) still be able to receive downlink OFDMA and respond to
trigger frames for uplink OFDMA that specify the position
and bandwidth for the non-AP STA relative to the channel
the AP is using. Therefore, they need to be aware of this,
and at least for some hardware (e.g. Intel) this awareness
is in the hardware. As a result, use of the "same" channel
may need to be split over two channel contexts where they
differ by the AP being used.

As a first step, introduce a concept of a channel request
('chanreq') for each interface, to control the context it
requests. This step does nothing but reorganise the code,
so that later the AP's chandef can be added to the request
in order to handle the EHT case described above.

Link: https://msgid.link/20240129194108.2e88e48bd2e9.I4256183debe975c5ed71621611206fdbb69ba330@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: clean up HE 6 GHz and EHT chandef parsing

In the code we currently check for support 80+80, 160
and 320 channel widths, but really the way this should
be (and is otherwise) handled is that we compute the
highest channel bandwidth given there, and then cut it
down to what we support. This is also needed for wider
bandwidth OFDMA support.

Change the code to remove this limitation and always
parse the highest possible channel width.

Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240129194108.d06f85082e29.I47e68ed3d97b0a2f4ee61e5d8abfcefc8a5b9c08@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: clean up connection process

Rewrite the station-side connection handling. The connection
flags (IEEE80211_DISABLE_*) are rather confusing, and they're
not always maintained well. Additionally, for wider-bandwidth
OFDMA support we need to know the precise bandwidth of the AP,
which is currently somewhat difficult.

Rewrite this to have a 'mode' (S1G/legacy/HT/...) and a limit
on the bandwidth. This is not entirely clean because some of
those modes aren't completely sequenced (as this assumes in
some places), e.g. VHT doesn't exist on 2.4 GHz, but HE does.
However, it still simplifies things and gives us a good idea
what we're operating as, so we can parse elements accordingly
etc.

This leaves a FIXME for puncturing, this is addressed in a
later patch.

Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240129194108.9451722c0110.I3e61f4cfe9da89008e1854160093c76a1e69dc2a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: use bandwidth indication element for CSA

In CSA, parse the (EHT) bandwidth indication element and
use it (in fact prefer it if present).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230920211508.43ef01920556.If4f24a61cd634ab1e50eba43899b9e992bf25602@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: separate out connection downgrade flags

Separate out the connection downgrade flags from the ifmgd->flags
and put them into the link information instead. While at it, make
them a separate sparse type so we don't get confused about where
they belong and have static checking on correct handling.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: 160MHz with extended NSS BW in CSA

Upon receiving CSA with 160MHz extended NSS BW from associated AP,
STA should set the HT operation_mode based on new_center_freq_seg1
because it is later used as ccfs2 in ieee80211_chandef_vht_oper().

Signed-off-by: Aviad Brikman <aviad.brikman@celeno.com>
Signed-off-by: Shay Bar <shay.bar@celeno.com>
Link: https://lore.kernel.org/r/20201222064714.24888-1-shay.bar@celeno.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: avoid using ext NSS high BW if not supported

If the AP advertises inconsistent data, namely it has CCFS1 or CCFS2,
but doesn't advertise support for 160/80+80 bandwidth or "Extended NSS
BW Support", then we cannot use any MCSes in the the higher bandwidth.
Thus, avoid connecting with higher bandwidth since it's less efficient
that way.

Link: https://lore.kernel.org/r/20200528213443.0e55d40c3ccc.I6fd0b4708ebd087e5e46466c3e91f6efbcbef668@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mac80211: support max channel switch time element

2018 REVmd of the spec introduces the max channel switch time
element which is optionally included in beacons/probes when there
is a channel switch / extended channel switch element.
The value represents the maximum delay between the time the AP
transmitted the last beacon in current channel and the expected
time of the first beacon in the new channel, in TU.

Parse the value and pass it to the driver.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: add ability to parse CCFS2

With newer VHT implementations, it's necessary to look at the
HT operation's CCFS2 field to identify the actual bandwidth
used.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Do not disconnect on invalid operating class

Some APs include a non global operating class in their extended channel
switch information element. In such a case, as the operating class is not
known, mac80211 would decide to disconnect.

However the specification states that the operating class needs to be
taken from Annex E, but it does not specify from which table it should be
taken, so it is valid for an AP to use a non global operating class.

To avoid possibly unneeded disconnection, in such a case ignore the
operating class and assume that the current band is used, and if the
resulting channel and band configuration is invalid disconnect.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

networking: convert many more places to skb_put_zero()

There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.

The following spatch found many more and also removes the
now unnecessary casts:

@@
identifier p, p2;
expression len;
expression skb;
type t, t2;
@@
(
-p = skb_put(skb, len);
+p = skb_put_zero(skb, len);
|
-p = (t)skb_put(skb, len);
+p = skb_put_zero(skb, len);
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, len);
|
-memset(p, 0, len);
)

@@
type t, t2;
identifier p, p2;
expression skb;
@@
t *p;
...
(
-p = skb_put(skb, sizeof(t));
+p = skb_put_zero(skb, sizeof(t));
|
-p = (t *)skb_put(skb, sizeof(t));
+p = skb_put_zero(skb, sizeof(t));
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, sizeof(*p));
|
-memset(p, 0, sizeof(*p));
)

@@
expression skb, len;
@@
-memset(skb_put(skb, len), 0, len);
+skb_put_zero(skb, len);

Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: move clearing result into ieee80211_parse_ch_switch_ie()

Clear the csa_ie in ieee80211_parse_ch_switch_ie() where the data
is filled in, rather than in each caller.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: mark channel as unusable if a regulatory MESH CSA is received

In the Mesh Channel Switch Parameters (8.4.2.105) the reason is specified
to WLAN_REASON_MESH_CHAN_REGULATORY in the case that a regulatory
limitation was the cause for the switch. This means another station
detected a radar event.

Mark the channel as unusable if this happens.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
[sw: style cleanup, rebase]
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

ieee80211: rename CCFS1/CCFS2 to CCFS0/CCFS1

This matches the spec, and otherwise things are really
confusing with the next patch adding CCFS2.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: parse wide bandwidth channel switch IE with workaround

Continuing the workaround implemented in commit 23665aaf9170
("mac80211: Interoperability workaround for 80+80 and 160 MHz channels")
use the same code to parse the Wide Bandwidth Channel Switch element
by converting to VHT Operation element since the spec also just refers
to that for parsing semantics, particularly with the workaround.

While at it, remove some dead code - the IEEE80211_STA_DISABLE_40MHZ
flag can never be set at this point since it's checked earlier and the
wide_bw_chansw_ie pointer is set to NULL if it's set.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

cfg80211: remove enum ieee80211_band

This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: remove unused variable in ieee80211_parse_ch_switch_ie()

The ht_oper variable is assigned a value, but never used in
ieee80211_parse_ch_switch_ie(). Remove it.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: use secondary channel offset IE also beacons during CSA

If we are switching from an HT40+ to an HT40- channel (or vice-versa),
we need the secondary channel offset IE to specify what is the
post-CSA offset to be used. This applies both to beacons and to probe
responses.

In ieee80211_parse_ch_switch_ie() we were ignoring this IE from
beacons and using the *current* HT information IE instead. This was
causing us to use the same offset as before the switch.

Fix that by using the secondary channel offset IE also for beacons and
don't ever use the pre-switch offset. Additionally, remove the
"beacon" argument from ieee80211_parse_ch_switch_ie(), since it's not
needed anymore.

Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: fix the mesh channel switch support

Mesh STA receiving the mesh CSA action frame is not able to trigger
the mesh channel switch due to the incorrect handling and comparison
of mesh channel switch parameters element (MCSP)'s TTL. Make sure
the MCSP's TTL is updated accordingly before calling the
ieee80211_mesh_process_chnswitch. Also, we update the beacon before
forwarding the CSA action frame, so MCSP's precedence value and
initiator flag need to be updated prior to this.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: process mesh channel switching using beacon

Trigger the mesh channel switching procedure if the mesh STA
happens to miss the CSA action frame but able to receive the
beacon containing the CSA and MCSP elements from its peer
mesh STAs.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
[fix locking in ieee80211_mesh_process_chnswitch()]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: refactor the parsing of chan switch ie

Refactor the channel switch IE parsing to reduce the number
of function parameters.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: split off channel switch parsing function

The channel switch parsing function can be re-used for the IBSS code,
put the common part into an extra function.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[also move/rename chandef_downgrade]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Remove unnecessary OOM logging messages

Removing unnecessary messages saves code and text.

Site specific OOM messages are duplications of a generic MM
out of memory message and aren't really useful, so just
delete them.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: reduce reliance on netdev

For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.

In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: remove encrypt parameter from ieee80211_tx_skb

Since the flags moved into skb->cb, there's no
longer a need to have the encrypt bool passed
into the function, anyone who requires it set
to 0 (false) can just set the flag directly.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: move channel switch code

The channel switch code is currently in the spectrum
management file, where arguably it belongs. However,
it is for managed mode only and uses the structures
for that mode only so having it in a more generic
file can be confusing. Additionally, my next patch
gets simpler with the code here.

When/if we ever implement this for IBSS or mesh then
we will need to rework the structures it uses anyway
at which point we could move the code back.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

cfg80211: clean up includes

Trying to separate header files into net/wireless.h and
net/cfg80211.h has been a source of confusion. Remove
net/wireless.h (because there also is the linux/wireless.h)
and subsume everything into net/cfg80211.h -- except the
definitions for regulatory structures which get moved to
a new header net/regulatory.h.

The "new" net/cfg80211.h is now divided into sections.

There are no real changes in this patch but code shuffling
and some very minor documentation fixes.

I have also, to make things reflect reality, put in a
copyright line for Luis to net/regulatory.h since that
is probably exclusively written by him but was formerly
in a file that only had my copyright line.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: split IBSS/managed code

This patch splits out the ibss code and data from managed (station) mode.
The reason to do this is to better separate the state machines, and have
the code be contained better so it gets easier to determine what exactly
a given change will affect, that in turn makes it easier to understand.

This is quite some churn, especially because I split sdata->u.sta into
sdata->u.mgd and sdata->u.ibss, but I think it's easier to maintain that
way. I've also shuffled around some code -- null function sending is only
applicable to managed interfaces so put that into that file, some other
functions are needed from various places so put them into util, and also
rearranged the prototypes in ieee80211_i.h accordingly.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: use cfg80211s BSS infrastructure

Remove all the code from mac80211 to keep track of BSSes
and use the cfg80211-provided code completely.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Handle power constraint level advertised in 11d+h beacon

This patch uses power constraint level while determining the maximum
transmit power, there by it makes sure that any power mitigation
requirement for the channel in the current regulatory domain is met.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: 802.11w - Do not force Action frames to disable encryption

When sending out Action frames, allow ieee80211_tx_skb() to send them
without enforcing do_not_encrypt. These frames will be encrypted if
MFP has been negotiated.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Add 802.11h CSA support

Move to the advertised channel on reception of
a CSA element. This is needed for 802.11h compliance.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: move frame TX function

The ieee80211_sta_tx function isn't MLME code any more,
it's getting used by a lot of code. Move it to utils and
rename it to ieee80211_tx_skb.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: move spectrum management code out

Like the HT code, this doesn't depend on the STA-mode implementation
and can be handled entirely independently. There's only stub code
for now, but when it gets filled having it in its own file will be
beneficial.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>