wifi: cfg80211: do some rework towards MLO link APIs

In order to support multi-link operation with multiple links,
start adding some APIs. The notable addition here is to have
the link ID in a new nl80211 attribute, that will be used to
differentiate the links in many nl80211 operations.

So far, this patch adds the netlink NL80211_ATTR_MLO_LINK_ID
attribute (as well as the NL80211_ATTR_MLO_LINKS attribute)
and plugs it through the system in some places, checking the
validity etc. along with other infrastructure needed for it.

For now, I've decided to include only the over-the-air link
ID in the API. I know we discussed that we eventually need to
have to have other ways of identifying a link, but for local
AP mode and auth/assoc commands as well as set_key etc. we'll
use the OTA ID.

Also included in this patch is some refactoring of the data
structures in struct wireless_dev, splitting for the first
time the data into type dependent pieces, to make reasoning
about these things easier.

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

1 files changed, 37 insertions, 7 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index a60d7d638e72..b7257862e0fe 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -5,7 +5,7 @@
  * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright 2017	Intel Deutschland GmbH
- * Copyright (C) 2018-2021 Intel Corporation
+ * Copyright (C) 2018-2022 Intel Corporation
  */
 #include <linux/export.h>
 #include <linux/bitops.h>
@@ -1041,7 +1041,6 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 			return -EBUSY;
 
 		dev->ieee80211_ptr->use_4addr = false;
-		dev->ieee80211_ptr->mesh_id_up_len = 0;
 		wdev_lock(dev->ieee80211_ptr);
 		rdev_set_qos_map(rdev, dev, NULL);
 		wdev_unlock(dev->ieee80211_ptr);
@@ -1049,7 +1048,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 		switch (otype) {
 		case NL80211_IFTYPE_AP:
 		case NL80211_IFTYPE_P2P_GO:
-			cfg80211_stop_ap(rdev, dev, true);
+			cfg80211_stop_ap(rdev, dev, -1, true);
 			break;
 		case NL80211_IFTYPE_ADHOC:
 			cfg80211_leave_ibss(rdev, dev, false);
@@ -1073,6 +1072,11 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 
 		cfg80211_process_rdev_events(rdev);
 		cfg80211_mlme_purge_registrations(dev->ieee80211_ptr);
+
+		memset(&dev->ieee80211_ptr->u, 0,
+		       sizeof(dev->ieee80211_ptr->u));
+		memset(&dev->ieee80211_ptr->links, 0,
+		       sizeof(dev->ieee80211_ptr->links));
 	}
 
 	err = rdev_change_virtual_intf(rdev, dev, ntype, params);
@@ -1930,6 +1934,24 @@ bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
 }
 EXPORT_SYMBOL(ieee80211_chandef_to_operating_class);
 
+static int cfg80211_wdev_bi(struct wireless_dev *wdev)
+{
+	switch (wdev->iftype) {
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_P2P_GO:
+		WARN_ON(wdev->valid_links);
+		return wdev->links[0].ap.beacon_interval;
+	case NL80211_IFTYPE_MESH_POINT:
+		return wdev->u.mesh.beacon_interval;
+	case NL80211_IFTYPE_ADHOC:
+		return wdev->u.ibss.beacon_interval;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int,
 				       u32 *beacon_int_gcd,
 				       bool *beacon_int_different)
@@ -1940,19 +1962,27 @@ static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int,
 	*beacon_int_different = false;
 
 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
-		if (!wdev->beacon_interval)
+		int wdev_bi;
+
+		/* this feature isn't supported with MLO */
+		if (wdev->valid_links)
+			continue;
+
+		wdev_bi = cfg80211_wdev_bi(wdev);
+
+		if (!wdev_bi)
 			continue;
 
 		if (!*beacon_int_gcd) {
-			*beacon_int_gcd = wdev->beacon_interval;
+			*beacon_int_gcd = wdev_bi;
 			continue;
 		}
 
-		if (wdev->beacon_interval == *beacon_int_gcd)
+		if (wdev_bi == *beacon_int_gcd)
 			continue;
 
 		*beacon_int_different = true;
-		*beacon_int_gcd = gcd(*beacon_int_gcd, wdev->beacon_interval);
+		*beacon_int_gcd = gcd(*beacon_int_gcd, wdev_bi);
 	}
 
 	if (new_beacon_int && *beacon_int_gcd != new_beacon_int) {