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>

3 files changed, 78 insertions, 40 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index c3180dc03a33..c61bcdd3dfbc 100644
--- a/net/wireless/chan.c
+++ b/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;
 
-        width = cfg80211_chandef_get_width(chandef);
-        if (width < 0)
-                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,
-                                            width);
-        if (r)
-                return r;
+                ret = cfg80211_get_chans_dfs_required(wiphy,
+                                                      chandef->center_freq1,
+                                                      width);
+                if (ret < 0)
+                        return ret;
+                else if (ret > 0)
+                        return BIT(chandef->width);
 
-        if (!chandef->center_freq2)
-                return 0;
+                if (!chandef->center_freq2)
+                        return 0;
+
+                ret = cfg80211_get_chans_dfs_required(wiphy,
+                                                      chandef->center_freq2,
+                                                      width);
+                if (ret < 0)
+                        return ret;
+                else if (ret > 0)
+                        return BIT(chandef->width);
 
-        return cfg80211_get_chans_dfs_required(wiphy, chandef->center_freq2,
-                                               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;
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 7031ee0afad8..6ebe883653a4 100644
--- a/net/wireless/mesh.c
+++ b/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,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 85bc830fd7e3..4f82b9b71db1 100644
--- a/net/wireless/nl80211.c
+++ b/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;
 
@@ -5942,22 +5946,15 @@ skip_beacons:
                                      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);
-                if (err < 0)
-                        return err;
-                if (err) {
-                        radar_detect_width = BIT(params.chandef.width);
-                        params.radar_required = true;
-                }
-                break;
-        default:
-                break;
+        err = cfg80211_chandef_dfs_required(wdev->wiphy,
+                                            &params.chandef,
+                                            wdev->iftype);
+        if (err < 0)
+                return err;
+
+        if (err > 0) {
+                radar_detect_width = BIT(params.chandef.width);
+                params.radar_required = true;
         }
 
         err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,