cfg80211/mac80211: refactor cfg80211_chandef_dfs_required()

Some interface types don't require DFS (such as STATION, P2P_CLIENT
etc).  In order to centralize these decisions, make
cfg80211_chandef_dfs_required() take the iftype into consideration.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -446,10 +446,13 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
  * cfg80211_chandef_dfs_required - checks if radar detection is required
  * @wiphy: the wiphy to validate against
  * @chandef: the channel definition to check
- * Return: 1 if radar detection is required, 0 if it is not, < 0 on error
+ * @iftype: the interface type as specified in &enum nl80211_iftype
+ * Returns:
+ *	1 if radar detection is required, 0 if it is not, < 0 on error
  */
 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
-				  const struct cfg80211_chan_def *chandef);
+				  const struct cfg80211_chan_def *chandef,
+				  enum nl80211_iftype);
 
 /**
  * ieee80211_chandef_rate_flags - returns rate flags for a channel

net/mac80211/ibss.c

@@ -228,7 +228,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	struct beacon_data *presp;
 	enum nl80211_bss_scan_width scan_width;
 	bool have_higher_than_11mbit;
-	bool radar_required = false;
+	bool radar_required;
 	int err;
 
 	sdata_assert_lock(sdata);
@@ -284,20 +284,19 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	}
 
 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
-					    &chandef);
+					    &chandef, NL80211_IFTYPE_ADHOC);
 	if (err < 0) {
 		sdata_info(sdata,
 			   "Failed to join IBSS, invalid chandef\n");
 		return;
 	}
-	if (err > 0) {
-		if (!ifibss->userspace_handles_dfs) {
+	if (err > 0 && !ifibss->userspace_handles_dfs) {
 		sdata_info(sdata,
 			   "Failed to join IBSS, DFS channel without control program\n");
 		return;
 	}
-		radar_required = true;
-	}
+
+	radar_required = err;
 
 	mutex_lock(&local->mtx);
 	if (ieee80211_vif_use_channel(sdata, &chandef,
@@ -777,7 +776,8 @@ static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
 	 * unavailable.
 	 */
 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
-					    &ifibss->chandef);
+					    &ifibss->chandef,
+					    NL80211_IFTYPE_ADHOC);
 	if (err > 0)
 		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
 				     GFP_ATOMIC);
@@ -876,17 +876,17 @@ ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	}
 
 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
-					    &params.chandef);
+					    &params.chandef,
+					    NL80211_IFTYPE_ADHOC);
 	if (err < 0)
 		goto disconnect;
-	if (err) {
+	if (err > 0 && !ifibss->userspace_handles_dfs) {
 		/* IBSS-DFS only allowed with a control program */
-		if (!ifibss->userspace_handles_dfs)
 		goto disconnect;
-
-		params.radar_required = true;
 	}
 
+	params.radar_required = err;
+
 	if (cfg80211_chandef_identical(&params.chandef,
 				       &sdata->vif.bss_conf.chandef)) {
 		ibss_dbg(sdata,

net/mac80211/mesh.c

@@ -903,14 +903,15 @@ ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
 	}
 
 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
-					    &params.chandef);
+					    &params.chandef,
+					    NL80211_IFTYPE_MESH_POINT);
 	if (err < 0)
 		return false;
-	if (err) {
-		params.radar_required = true;
+	if (err > 0)
 		/* TODO: DFS not (yet) supported */
 		return false;
-	}
+
+	params.radar_required = err;
 
 	if (cfg80211_chandef_identical(&params.chandef,
 				       &sdata->vif.bss_conf.chandef)) {

net/wireless/chan.c

@@ -326,28 +326,57 @@ static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
 
 
 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
-				  const struct cfg80211_chan_def *chandef)
+				  const struct cfg80211_chan_def *chandef,
+				  enum nl80211_iftype iftype)
 {
 	int width;
-	int r;
+	int ret;
 
 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 		return -EINVAL;
 
+	switch (iftype) {
+	case NL80211_IFTYPE_ADHOC:
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_P2P_GO:
+	case NL80211_IFTYPE_MESH_POINT:
 		width = cfg80211_chandef_get_width(chandef);
 		if (width < 0)
 			return -EINVAL;
 
-	r = cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq1,
+		ret = cfg80211_get_chans_dfs_required(wiphy,
+						      chandef->center_freq1,
 						      width);
-	if (r)
-		return r;
+		if (ret < 0)
+			return ret;
+		else if (ret > 0)
+			return BIT(chandef->width);
 
 		if (!chandef->center_freq2)
 			return 0;
 
-	return cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq2,
+		ret = cfg80211_get_chans_dfs_required(wiphy,
+						      chandef->center_freq2,
 						      width);
+		if (ret < 0)
+			return ret;
+		else if (ret > 0)
+			return BIT(chandef->width);
+
+		break;
+	case NL80211_IFTYPE_STATION:
+	case NL80211_IFTYPE_P2P_CLIENT:
+	case NL80211_IFTYPE_MONITOR:
+	case NL80211_IFTYPE_AP_VLAN:
+	case NL80211_IFTYPE_WDS:
+	case NL80211_IFTYPE_P2P_DEVICE:
+	case NL80211_IFTYPE_UNSPECIFIED:
+		break;
+	case NUM_NL80211_IFTYPES:
+		WARN_ON(1);
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
 
@@ -749,7 +778,8 @@ bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
 	    !cfg80211_go_permissive_chan(rdev, chandef->chan))
 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
 
-	if (cfg80211_chandef_dfs_required(wiphy, chandef) > 0 &&
+	if (cfg80211_chandef_dfs_required(wiphy, chandef,
+					  NL80211_IFTYPE_UNSPECIFIED) > 0 &&
 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
 		prohibited_flags = IEEE80211_CHAN_DISABLED;
@@ -779,6 +809,8 @@ cfg80211_get_chan_state(struct wireless_dev *wdev,
 		        enum cfg80211_chan_mode *chanmode,
 		        u8 *radar_detect)
 {
+	int ret;
+
 	*chan = NULL;
 	*chanmode = CHAN_MODE_UNDEFINED;
 
@@ -821,8 +853,11 @@ cfg80211_get_chan_state(struct wireless_dev *wdev,
 			*chan = wdev->chandef.chan;
 			*chanmode = CHAN_MODE_SHARED;
 
-			if (cfg80211_chandef_dfs_required(wdev->wiphy,
-							  &wdev->chandef))
+			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
+							    &wdev->chandef,
+							    wdev->iftype);
+			WARN_ON(ret < 0);
+			if (ret > 0)
 				*radar_detect |= BIT(wdev->chandef.width);
 		}
 		return;
@@ -831,8 +866,11 @@ cfg80211_get_chan_state(struct wireless_dev *wdev,
 			*chan = wdev->chandef.chan;
 			*chanmode = CHAN_MODE_SHARED;
 
-			if (cfg80211_chandef_dfs_required(wdev->wiphy,
-							  &wdev->chandef))
+			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
+							    &wdev->chandef,
+							    wdev->iftype);
+			WARN_ON(ret < 0);
+			if (ret > 0)
 				*radar_detect |= BIT(wdev->chandef.width);
 		}
 		return;

net/wireless/mesh.c

@@ -179,10 +179,13 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 				     NL80211_IFTYPE_MESH_POINT))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy, &setup->chandef);
+	err = cfg80211_chandef_dfs_required(wdev->wiphy,
+					    &setup->chandef,
+					    NL80211_IFTYPE_MESH_POINT);
 	if (err < 0)
 		return err;
-	if (err)
+
+	if (err > 0)
 		radar_detect_width = BIT(setup->chandef.width);
 
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,

net/wireless/nl80211.c

@@ -3275,12 +3275,15 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 				     wdev->iftype))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy, &params.chandef);
+	err = cfg80211_chandef_dfs_required(wdev->wiphy,
+					    &params.chandef,
+					    NL80211_IFTYPE_AP);
 	if (err < 0)
 		return err;
-	if (err) {
-		radar_detect_width = BIT(params.chandef.width);
+
+	if (err > 0) {
 		params.radar_required = true;
+		radar_detect_width = BIT(params.chandef.width);
 	}
 
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
@@ -5806,7 +5809,8 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 	if (wdev->cac_started)
 		return -EBUSY;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy, &chandef);
+	err = cfg80211_chandef_dfs_required(wdev->wiphy, &chandef,
+					    NL80211_IFTYPE_UNSPECIFIED);
 	if (err < 0)
 		return err;
 
@@ -5942,23 +5946,16 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 				     wdev->iftype))
 		return -EINVAL;
 
-	switch (dev->ieee80211_ptr->iftype) {
-	case NL80211_IFTYPE_AP:
-	case NL80211_IFTYPE_P2P_GO:
-	case NL80211_IFTYPE_ADHOC:
-	case NL80211_IFTYPE_MESH_POINT:
 	err = cfg80211_chandef_dfs_required(wdev->wiphy,
-						    &params.chandef);
+					    &params.chandef,
+					    wdev->iftype);
 	if (err < 0)
 		return err;
-		if (err) {
+
+	if (err > 0) {
 		radar_detect_width = BIT(params.chandef.width);
 		params.radar_required = true;
 	}
-		break;
-	default:
-		break;
-	}
 
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
 					   params.chandef.chan,