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, 136 insertions, 60 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index f74f176e0d9d..efc2de4bab57 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -672,14 +672,21 @@ bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
  * range of chandef.
  */
 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
-			  struct ieee80211_channel *chan)
+			  struct ieee80211_channel *chan,
+			  bool primary_only)
 {
 	int width;
 	u32 freq;
 
+	if (!chandef->chan)
+		return false;
+
 	if (chandef->chan->center_freq == chan->center_freq)
 		return true;
 
+	if (primary_only)
+		return false;
+
 	width = cfg80211_chandef_get_width(chandef);
 	if (width <= 20)
 		return false;
@@ -704,23 +711,25 @@ bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
 
 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
 {
-	bool active = false;
+	unsigned int link;
 
 	ASSERT_WDEV_LOCK(wdev);
 
-	if (!wdev->chandef.chan)
-		return false;
-
 	switch (wdev->iftype) {
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
-		active = wdev->beacon_interval != 0;
+		for_each_valid_link(wdev, link) {
+			if (wdev->links[link].ap.beacon_interval)
+				return true;
+		}
 		break;
 	case NL80211_IFTYPE_ADHOC:
-		active = wdev->ssid_len != 0;
+		if (wdev->u.ibss.ssid_len)
+			return true;
 		break;
 	case NL80211_IFTYPE_MESH_POINT:
-		active = wdev->mesh_id_len != 0;
+		if (wdev->u.mesh.id_len)
+			return true;
 		break;
 	case NL80211_IFTYPE_STATION:
 	case NL80211_IFTYPE_OCB:
@@ -737,7 +746,35 @@ bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
 		WARN_ON(1);
 	}
 
-	return active;
+	return false;
+}
+
+bool cfg80211_wdev_on_sub_chan(struct wireless_dev *wdev,
+			       struct ieee80211_channel *chan,
+			       bool primary_only)
+{
+	unsigned int link;
+
+	switch (wdev->iftype) {
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_P2P_GO:
+		for_each_valid_link(wdev, link) {
+			if (cfg80211_is_sub_chan(&wdev->links[link].ap.chandef,
+						 chan, primary_only))
+				return true;
+		}
+		break;
+	case NL80211_IFTYPE_ADHOC:
+		return cfg80211_is_sub_chan(&wdev->u.ibss.chandef, chan,
+					    primary_only);
+	case NL80211_IFTYPE_MESH_POINT:
+		return cfg80211_is_sub_chan(&wdev->u.mesh.chandef, chan,
+					    primary_only);
+	default:
+		break;
+	}
+
+	return false;
 }
 
 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
@@ -752,7 +789,7 @@ static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
 			continue;
 		}
 
-		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
+		if (cfg80211_wdev_on_sub_chan(wdev, chan, false)) {
 			wdev_unlock(wdev);
 			return true;
 		}
@@ -772,7 +809,8 @@ cfg80211_offchan_chain_is_active(struct cfg80211_registered_device *rdev,
 	if (!cfg80211_chandef_valid(&rdev->background_radar_chandef))
 		return false;
 
-	return cfg80211_is_sub_chan(&rdev->background_radar_chandef, channel);
+	return cfg80211_is_sub_chan(&rdev->background_radar_chandef, channel,
+				    false);
 }
 
 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
@@ -1176,6 +1214,68 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 }
 EXPORT_SYMBOL(cfg80211_chandef_usable);
 
+static bool cfg80211_ir_permissive_check_wdev(enum nl80211_iftype iftype,
+					      struct wireless_dev *wdev,
+					      struct ieee80211_channel *chan)
+{
+	struct ieee80211_channel *other_chan = NULL;
+	unsigned int link_id;
+	int r1, r2;
+
+	for_each_valid_link(wdev, link_id) {
+		if (wdev->iftype == NL80211_IFTYPE_STATION &&
+		    wdev->links[link_id].client.current_bss)
+			other_chan = wdev->links[link_id].client.current_bss->pub.channel;
+
+		/*
+		 * If a GO already operates on the same GO_CONCURRENT channel,
+		 * this one (maybe the same one) can beacon as well. We allow
+		 * the operation even if the station we relied on with
+		 * GO_CONCURRENT is disconnected now. But then we must make sure
+		 * we're not outdoor on an indoor-only channel.
+		 */
+		if (iftype == NL80211_IFTYPE_P2P_GO &&
+		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
+		    wdev->links[link_id].ap.beacon_interval &&
+		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
+			other_chan = wdev->links[link_id].ap.chandef.chan;
+
+		if (!other_chan)
+			continue;
+
+		if (chan == other_chan)
+			return true;
+
+		if (chan->band != NL80211_BAND_5GHZ &&
+		    chan->band != NL80211_BAND_6GHZ)
+			continue;
+
+		r1 = cfg80211_get_unii(chan->center_freq);
+		r2 = cfg80211_get_unii(other_chan->center_freq);
+
+		if (r1 != -EINVAL && r1 == r2) {
+			/*
+			 * At some locations channels 149-165 are considered a
+			 * bundle, but at other locations, e.g., Indonesia,
+			 * channels 149-161 are considered a bundle while
+			 * channel 165 is left out and considered to be in a
+			 * different bundle. Thus, in case that there is a
+			 * station interface connected to an AP on channel 165,
+			 * it is assumed that channels 149-161 are allowed for
+			 * GO operations. However, having a station interface
+			 * connected to an AP on channels 149-161, does not
+			 * allow GO operation on channel 165.
+			 */
+			if (chan->center_freq == 5825 &&
+			    other_chan->center_freq != 5825)
+				continue;
+			return true;
+		}
+	}
+
+	return false;
+}
+
 /*
  * Check if the channel can be used under permissive conditions mandated by
  * some regulatory bodies, i.e., the channel is marked with
@@ -1219,59 +1319,14 @@ static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
 	 * the current registered device.
 	 */
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
-		struct ieee80211_channel *other_chan = NULL;
-		int r1, r2;
+		bool ret;
 
 		wdev_lock(wdev);
-		if (wdev->iftype == NL80211_IFTYPE_STATION &&
-		    wdev->current_bss)
-			other_chan = wdev->current_bss->pub.channel;
-
-		/*
-		 * If a GO already operates on the same GO_CONCURRENT channel,
-		 * this one (maybe the same one) can beacon as well. We allow
-		 * the operation even if the station we relied on with
-		 * GO_CONCURRENT is disconnected now. But then we must make sure
-		 * we're not outdoor on an indoor-only channel.
-		 */
-		if (iftype == NL80211_IFTYPE_P2P_GO &&
-		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
-		    wdev->beacon_interval &&
-		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
-			other_chan = wdev->chandef.chan;
+		ret = cfg80211_ir_permissive_check_wdev(iftype, wdev, chan);
 		wdev_unlock(wdev);
 
-		if (!other_chan)
-			continue;
-
-		if (chan == other_chan)
-			return true;
-
-		if (chan->band != NL80211_BAND_5GHZ &&
-		    chan->band != NL80211_BAND_6GHZ)
-			continue;
-
-		r1 = cfg80211_get_unii(chan->center_freq);
-		r2 = cfg80211_get_unii(other_chan->center_freq);
-
-		if (r1 != -EINVAL && r1 == r2) {
-			/*
-			 * At some locations channels 149-165 are considered a
-			 * bundle, but at other locations, e.g., Indonesia,
-			 * channels 149-161 are considered a bundle while
-			 * channel 165 is left out and considered to be in a
-			 * different bundle. Thus, in case that there is a
-			 * station interface connected to an AP on channel 165,
-			 * it is assumed that channels 149-161 are allowed for
-			 * GO operations. However, having a station interface
-			 * connected to an AP on channels 149-161, does not
-			 * allow GO operation on channel 165.
-			 */
-			if (chan->center_freq == 5825 &&
-			    other_chan->center_freq != 5825)
-				continue;
-			return true;
-		}
+		if (ret)
+			return ret;
 	}
 
 	return false;
@@ -1374,3 +1429,24 @@ bool cfg80211_any_usable_channels(struct wiphy *wiphy,
 	return false;
 }
 EXPORT_SYMBOL(cfg80211_any_usable_channels);
+
+struct cfg80211_chan_def *wdev_chandef(struct wireless_dev *wdev,
+				       unsigned int link_id)
+{
+	ASSERT_WDEV_LOCK(wdev);
+
+	switch (wdev->iftype) {
+	case NL80211_IFTYPE_MESH_POINT:
+		return &wdev->u.mesh.chandef;
+	case NL80211_IFTYPE_ADHOC:
+		return &wdev->u.ibss.chandef;
+	case NL80211_IFTYPE_OCB:
+		return &wdev->u.ocb.chandef;
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_P2P_GO:
+		return &wdev->links[link_id].ap.chandef;
+	default:
+		return NULL;
+	}
+}
+EXPORT_SYMBOL(wdev_chandef);