[PATCH wireless 0/2] wifi: mac80211: fix link changes of 4-address MLD stations

[Piotr Kubik <piotr@kubik.pl>]

A 4-address (WDS) station of an AP MLD sits on an AP_VLAN interface.
Two faults appear when the links of such a station change, for
example when the station reassociates or removes a link with ML
reconfiguration:

- drv_change_sta_links() checks the AP_VLAN, which is never in the
  driver, so every link add fails with -EIO and a link removal stays
  in the driver.
- ieee80211_set_sta_4addr() adds the AP_VLAN links before it sets
  their addresses, so a link that the station gains later gets the
  zero address, and a second such link fails with -EALREADY. The
  station then stays on the AP interface.

Both come with 469d5d5a3b7a ("wifi: mac80211: synchronize valid links
for WDS AP_VLAN interfaces"). Tested with mt7996e on a 2-link AP MLD
(5 GHz + 6 GHz) and a 4-address non-AP MLD: after repeated
reassociation and after a link removal, the station stays on its
AP_VLAN with all of its links.

Piotr Kubik (2):
  wifi: mac80211: change the links of an AP_VLAN station through its AP
  wifi: mac80211: set the link addresses of a 4-address AP_VLAN before its links

  net/mac80211/cfg.c        |   17 ++++++++++-------
  net/mac80211/driver-ops.c |    1 +
  2 files changed, 11 insertions(+), 7 deletions(-)