cfg80211/mac80211: move interface counting for combination check to mac80211

Move the counting part of the interface combination check from
cfg80211 to mac80211.

This is needed to simplify locking when the driver has to perform a
combination check by itself (eg. with channel-switch).

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 93 insertions, 2 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 906bc3b05aae..8bf94eaa0456 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -972,7 +972,6 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	sdata->needed_rx_chains = sdata->local->rx_chains;
 
 	mutex_lock(&local->mtx);
-	sdata->radar_required = params->radar_required;
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
 	mutex_unlock(&local->mtx);
@@ -2930,7 +2929,6 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	/* whatever, but channel contexts should not complain about that one */
 	sdata->smps_mode = IEEE80211_SMPS_OFF;
 	sdata->needed_rx_chains = local->rx_chains;
-	sdata->radar_required = true;
 
 	err = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_SHARED);
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index b297bd3043a8..623b336f3efd 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -519,6 +519,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_chanctx *ctx;
+	u8 radar_detect_width = 0;
 	int ret;
 
 	lockdep_assert_held(&local->mtx);
@@ -526,6 +527,22 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 
 	mutex_lock(&local->chanctx_mtx);
+
+	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
+					    chandef,
+					    sdata->wdev.iftype);
+	if (ret < 0)
+		goto out;
+	if (ret > 0)
+		radar_detect_width = BIT(chandef->width);
+
+	sdata->radar_required = ret;
+
+	ret = ieee80211_check_combinations(sdata, chandef, mode,
+					   radar_detect_width);
+	if (ret < 0)
+		goto out;
+
 	__ieee80211_vif_release_channel(sdata);
 
 	ctx = ieee80211_find_chanctx(local, chandef, mode);
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 222c28b75315..09213fd87f8d 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1805,6 +1805,10 @@ int ieee80211_cs_headroom(struct ieee80211_local *local,
 			  enum nl80211_iftype iftype);
 void ieee80211_recalc_dtim(struct ieee80211_local *local,
 			   struct ieee80211_sub_if_data *sdata);
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 73af7398850b..436f98870066 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2797,3 +2797,75 @@ void ieee80211_recalc_dtim(struct ieee80211_local *local,
 
 	ps->dtim_count = dtim_count;
 }
+
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *sdata_iter;
+	enum nl80211_iftype iftype = sdata->wdev.iftype;
+	int num[NUM_NL80211_IFTYPES];
+	struct ieee80211_chanctx *ctx;
+	int num_different_channels = 1;
+	int total = 1;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	if (WARN_ON(hweight32(radar_detect) > 1))
+		return -EINVAL;
+
+	if (WARN_ON(chanmode == IEEE80211_CHANCTX_SHARED && !chandef->chan))
+		return -EINVAL;
+
+	if (WARN_ON(iftype >= NUM_NL80211_IFTYPES))
+		return -EINVAL;
+
+	/* Always allow software iftypes */
+	if (local->hw.wiphy->software_iftypes & BIT(iftype)) {
+		if (radar_detect)
+			return -EINVAL;
+		return 0;
+	}
+
+	memset(num, 0, sizeof(num));
+
+	if (iftype != NL80211_IFTYPE_UNSPECIFIED)
+		num[iftype] = 1;
+
+	list_for_each_entry(ctx, &local->chanctx_list, list) {
+		if (ctx->conf.radar_enabled)
+			radar_detect |= BIT(ctx->conf.def.width);
+		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) {
+			num_different_channels++;
+			continue;
+		}
+		if ((chanmode == IEEE80211_CHANCTX_SHARED) &&
+		    cfg80211_chandef_compatible(chandef,
+						&ctx->conf.def))
+			continue;
+		num_different_channels++;
+	}
+
+	list_for_each_entry_rcu(sdata_iter, &local->interfaces, list) {
+		struct wireless_dev *wdev_iter;
+
+		wdev_iter = &sdata_iter->wdev;
+
+		if (sdata_iter == sdata ||
+		    rcu_access_pointer(sdata_iter->vif.chanctx_conf) == NULL ||
+		    local->hw.wiphy->software_iftypes & BIT(wdev_iter->iftype))
+			continue;
+
+		num[wdev_iter->iftype]++;
+		total++;
+	}
+
+	if (total == 1 && !radar_detect)
+		return 0;
+
+	return cfg80211_check_combinations(local->hw.wiphy,
+					   num_different_channels,
+					   radar_detect, num);
+}