There are a couple of new things that should be possible
with MLO:
 * selecting the link to transmit to a station by link ID,
   which a previous patch added to the nl80211 API
 * selecting the link by frequency, similarly
 * allowing transmittion to an MLD without specifying any
   channel or link ID, with MLD addresses

Enable these use cases. Also fix the address comparison
in client mode to use the AP (MLD) address.

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

Since links can be added and removed dynamically, we need to
somehow protect the sdata->link[] and vif->link_conf[] array
pointers from disappearing when accessing them without locks.
RCU-ify the pointers to achieve this, which requires quite a
bit of rework.

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

Check all the MLO links to decide whether offchannel TX is needed.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Split the bss_info_changed method to vif_cfg_changed and
link_info_changed, with the latter getting a link ID.
Also change the 'changed' parameter to u64 already, we
know we need that.

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

Start reorganizing interface related data structures toward
MLD. The most complex part here is for the keys, since we
have to split the various kinds of GTKs off to the link but
still need to use (for WEP) the other keys as a fallback
even for multicast frames.

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

We'll use bss_conf for per-link configuration later, so
move out all the non-link-specific data out into a new
struct ieee80211_vif_cfg used in the vif.

Some adjustments were done with the following spatch:

    @@
    expression sdata;
    struct ieee80211_vif *vifp;
    identifier var = { assoc, ibss_joined, aid, arp_addr_list, arp_addr_cnt, ssid, ssid_len, s1g, ibss_creator };
    @@
    (
    -sdata->vif.bss_conf.var
    +sdata->vif.cfg.var
    |
    -vifp->bss_conf.var
    +vifp->cfg.var
    )

    @bss_conf@
    struct ieee80211_bss_conf *bss_conf;
    identifier var = { assoc, ibss_joined, aid, arp_addr_list, arp_addr_cnt, ssid, ssid_len, s1g, ibss_creator };
    @@
    -bss_conf->var
    +vif_cfg->var

(though more manual fixups were needed, e.g. replacing
"vif_cfg->" by "vif->cfg." in many files.)

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

To add MLD, reuse the bss_conf structure later for per-link
information, so move some things into it that are per link.

Most transformations were done with the following spatch:

    @@
    expression sdata;
    identifier var = { chanctx_conf, mu_mimo_owner, csa_active, color_change_active, color_change_color };
    @@
    -sdata->vif.var
    +sdata->vif.bss_conf.var

    @@
    struct ieee80211_vif *vif;
    identifier var = { chanctx_conf, mu_mimo_owner, csa_active, color_change_active, color_change_color };
    @@
    -vif->var
    +vif->bss_conf.var

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

Since we always track the BSSID there when we get associated,
these are equivalent, but ifmgd->bssid saves a dereference and
thus makes the code a bit smaller, and more readable.

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

Because we can miss AP wakeup (beacon) while scanning other channels,
it's better go into wakeup state and inform the AP of that upon
returning to the operating channel, rather than staying asleep and
waiting for the next TIM indicating traffic for us.

This saves precious time, especially when we only have 200ms inter-
scan period for monitoring the active connection.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1593420923-26668-1-git-send-email-loic.poulain@linaro.org
[rewrite commit message a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We want to reuse the functions and structs for other counters such as BSS
color change. Rename them to more generic names.

Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20200811080107.3615705-2-john@phrozen.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>