Some bands (S1G) define channels centered on a non-integer
MHz. Give ieee80211_channel and cfg80211_chan_def a
freq_offset component where the final frequency can be
expressed as:

MHZ_TO_KHZ(chan->center_freq) + chan->freq_offset;

Also provide some helper functions to do the frequency
conversion and test for equality.

Retain the existing interface to frequency and channel
conversion helpers, and expose new ones which handle
frequencies in units of KHz.

Some internal functions (net/wireless/chan.c) pass around
a frequency value. Convert these to units of KHz.

mesh, ibss, wext, etc. are currently ignored.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200402011810.22947-3-thomas@adapt-ip.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Minor comment conflict in mac80211.

Signed-off-by: David S. Miller <davem@davemloft.net>

When cfg80211_update_assoc_bss_entry() is called, there is a
verification that the BSS channel actually changed. As some APs use
CSA also for bandwidth changes, this would result with a kernel
warning.

Fix this by removing the WARN_ON().

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.96316ada0e8d.I6710376b1b4257e5f4712fc7ab16e2b638d512aa@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The only driver that used that was iwlwifi and it removed
support for this. Remove the feature here as well.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200214232336.a530de38e511.I393bc395f6037c8cca6421ed550e3072dc248aed@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

rdev->sched_scan_req_list maybe traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of rtnl_mutex.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover <frextrite@gmail.com>
Link: https://lore.kernel.org/r/20200219091102.10709-1-frextrite@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

cfg80211_update_notlisted_nontrans() leaves the RCU critical session
too early, while still using nontrans_ssid which is RCU protected. In
addition, it performs a bunch of RCU pointer update operations such
as rcu_access_pointer and rcu_assign_pointer.

The caller, cfg80211_inform_bss_frame_data(), also accesses the RCU
pointer without holding the lock.

Just wrap all of this with bss_lock.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20191004123706.15768-3-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The code copying the data assumes that the SSID element is
before the MBSSID element, but since the data is untrusted
from the AP, this cannot be guaranteed.

Validate that this is indeed the case and ignore the MBSSID
otherwise, to avoid having to deal with both cases for the
copy of data that should be between them.

Cc: stable@vger.kernel.org
Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Link: https://lore.kernel.org/r/1569009255-I1673911f5eae02964e21bdc11b2bf58e5e207e59@changeid
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>

This patch implements minor refactoring for cfg80211_bss_update function.
Code path for updating known BSS is extracted into dedicated
cfg80211_update_known_bss function.

Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20190726163922.27509-2-sergey.matyukevich.os@quantenna.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If we just read jiffies over and over again, a non-transmitting
entry may have a newer timestamp than the transmitting one,
leading to possible confusion on expiry. Give them all the same
timestamp when creating them.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20190703133823.10530-3-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>