[ Upstream commit 9bdaf3b91efd229dd272b228e13df10310c80d19 ]

There's a race condition in the netdev registration in that
NETDEV_REGISTER actually happens after the netdev is available,
and so if we initialize things only there, we might get called
with an uninitialized wdev through nl80211 - not using a wdev
but using a netdev interface index.

I found this while looking into a syzbot report, but it doesn't
really seem to be related, and unfortunately there's no repro
for it (yet). I can't (yet) explain how it managed to get into
cfg80211_release_pmsr() from nl80211_netlink_notify() without
the wdev having been initialized, as the latter only iterates
the wdevs that are linked into the rdev, which even without the
change here happened after init.

However, looking at this, it seems fairly clear that the init
needs to be done earlier, otherwise we might even re-init on a
netns move, when data might still be pending.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20201009135821.fdcbba3aad65.Ie9201d91dbcb7da32318812effdc1561aeaf4cdc@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Lockdep reports that we may deadlock because we take the RTNL on
the work struct, but flush it under RTNL. Clearly, it's correct.
In practice, this can happen when doing rfkill on an active device.

Fix this by moving the work struct to the wiphy (registered dev)
layer, and iterate over all the wdevs inside there. This then
means we need to track which one of them has work to do, so we
don't update to the driver for all wdevs all the time.

Also fix a locking bug I noticed while working on this - the
registrations list is iterated as if it was an RCU list, but it
isn't handle that way - and we need to lock now for the update
flag anyway, so remove the RCU.

Fixes: 6cd536fe62ef ("cfg80211: change internal management frame registration API")
Reported-by: Markus Theil <markus.theil@tu-ilmenau.de>
Reported-and-tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200604120420.b1dc540a7e26.I55dcca56bb5bdc5d7ad66a36a0b42afd7034d8be@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200507183909.GA12993@embeddedor
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

For DPP, there's a need to receive multicast action frames,
but many drivers need a special filter configuration for this.

Support announcing from userspace in the management registration
that multicast RX is required, with an extended feature flag if
the driver handles this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200417124013.c46238801048.Ib041d437ce0bff28a0c6d5dc915f68f1d8591002@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Almost all drivers below cfg80211 get the API wrong (except for
cfg80211) and are unable to cope with multiple registrations for
the same frame type, which is valid due to the match filter.
This seems to indicate the API is wrong, and we should maintain
the full information in cfg80211 instead of the drivers.

Change the API to no longer inform the driver about individual
registrations and unregistrations, but rather every time about
the entire state of the entire wiphy and single wdev, whenever
it may have changed. This also simplifies the code in cfg80211
as it no longer has to track exactly what was unregistered and
can free things immediately.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200417124300.f47f3828afc8.I7f81ef59c2c5a340d7075fb3c6d0e08e8aeffe07@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

To support Pre Association Security Negotiation (PASN) while already
associated to one AP, allow user space to register to Rx
authentication frames, so that the user space logic would be able to
receive/handle authentication frames from a different AP as part of
PASN.

Note that it is expected that user space would intelligently register
for Rx authentication frames, i.e., only when PASN is used and
configure a match filter only for PASN authentication algorithm, as
otherwise the MLME functionality of mac80211 would be broken.

Additionally, since some versions of the user space daemons wrongly
register to all types of authentication frames (which might result in
unexpected behavior) allow such registration if the request is for a
specific authentication algorithm number.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20200131114529.894206-1-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When the RFKILL subsystem isn't available, then rfkill_blocked()
always returns false. In the case of hardware rfkill this will
be wrong though, as if the hardware reported being killed then
it cannot operate any longer.

Since we only ever call the rfkill_sync work in this case, just
rename it to rfkill_block and always pass "true" for the blocked
parameter, rather than passing rfkill_blocked().

We rely on the underlying driver to still reject any new attempt
to bring up the device by itself.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-2-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When associated BSS completes channel switch procedure, its channel
record needs to be updated. The existing mac80211 solution was
extended to cfg80211 in commit 5dc8cdce1d72 ("mac80211/cfg80211:
update bss channel on channel switch").

However that solution still appears to be incomplete as it may lead
to duplicated scan entries for associated BSS after channel switch.
The root cause of the problem is as follows. Each BSS entry is
included into the following data structures:
- bss list rdev->bss_list
- bss search tree rdev->bss_tree
Updating BSS channel record without rebuilding bss_tree may break
tree search since cmp_bss considers all of the following: channel,
bssid, ssid. When BSS channel is updated, but its location in bss_tree
is not updated, then subsequent search operations may fail to locate
this BSS since they will be traversing bss_tree in wrong direction.
As a result, for scan performed after associated BSS channel switch,
cfg80211_bss_update may add the second entry for the same BSS to both
bss_list and bss_tree, rather then update the existing one.

To summarize, if BSS channel needs to be updated, then bss_tree should
be rebuilt in order to put updated BSS entry into a proper location.

This commit suggests the following straightforward solution:
- if new entry has been already created for BSS after channel switch,
  then use its IEs to update known BSS entry and then remove new
  entry completely
- use rb_erase/rb_insert_bss reinstall updated BSS in bss_tree
- for nontransmit BSS entry, the whole transmit BSS hierarchy
  is updated

Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20190726163922.27509-3-sergey.matyukevich.os@quantenna.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If the BSS is expired during connection, the connect result will
trigger a kernel warning. Ideally cfg80211 should hold the BSS
before the connection is attempted, but as the BSSID is not known
in case of auth/assoc MLME offload (connect op) it doesn't.

For those drivers without the connect op cfg80211 holds down the
reference so it wil not be removed from list.

Fix this by removing the warning and silently adding the BSS back to
the bss list which is return by the driver (with proper BSSID set) or
in case the BSS is already added use that.

The requirements for drivers are documented in the API's.

Signed-off-by: Chaitanya Tata <chaitanya.tata@bluwireless.co.uk>
[formatting fixes, keep old timestamp]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Merge net-next to resolve a conflict and to get the mac80211
rhashtable fixes so further patches can be applied on top.

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