cfg80211: rework chandef checking and export it

Some of the chandef checking that we do in cfg80211
to check if a channel is supported or not is also
needed in mac80211, so rework that a bit and export
the functions that are needed.

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

4 files changed, 85 insertions, 72 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e78db2cf3d1b..a238f41e55c2 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -58,6 +58,8 @@
  * structures here describe these capabilities in detail.
  */
 
+struct wiphy;
+
 /*
  * wireless hardware capability structures
  */
@@ -388,6 +390,22 @@ cfg80211_chandef_compatible(const struct cfg80211_chan_def *chandef1,
                             const struct cfg80211_chan_def *chandef2);
 
 /**
+ * cfg80211_chandef_valid - check if a channel definition is valid
+ * @chandef: the channel definition to check
+ */
+bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef);
+
+/**
+ * cfg80211_chandef_usable - check if secondary channels can be used
+ * @wiphy: the wiphy to validate against
+ * @chandef: the channel definition to check
+ * @prohibited_flags: the regulatory chanenl flags that must not be set
+ */
+bool cfg80211_chandef_usable(struct wiphy *wiphy,
+                             const struct cfg80211_chan_def *chandef,
+                             u32 prohibited_flags);
+
+/**
  * enum survey_info_flags - survey information flags
  *
  * @SURVEY_INFO_NOISE_DBM: noise (in dBm) was filled in
@@ -1045,9 +1063,6 @@ struct ieee80211_txq_params {
         u8 aifs;
 };
 
-/* from net/wireless.h */
-struct wiphy;
-
 /**
  * DOC: Scanning and BSS list handling
  *
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index bf2dfd54ff3b..b5f69831e318 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -44,7 +44,7 @@ void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
 }
 EXPORT_SYMBOL(cfg80211_chandef_create);
 
-bool cfg80211_chan_def_valid(const struct cfg80211_chan_def *chandef)
+bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 {
         u32 control_freq;
 
@@ -105,6 +105,7 @@ bool cfg80211_chan_def_valid(const struct cfg80211_chan_def *chandef)
 
         return true;
 }
+EXPORT_SYMBOL(cfg80211_chandef_valid);
 
 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
                                   int *pri40, int *pri80)
@@ -187,9 +188,9 @@ cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
 }
 EXPORT_SYMBOL(cfg80211_chandef_compatible);
 
-bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
-                                 u32 center_freq, u32 bandwidth,
-                                 u32 prohibited_flags)
+static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
+                                        u32 center_freq, u32 bandwidth,
+                                        u32 prohibited_flags)
 {
         struct ieee80211_channel *c;
         u32 freq;
@@ -205,55 +206,88 @@ bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
         return true;
 }
 
-static bool cfg80211_check_beacon_chans(struct wiphy *wiphy,
-                                        u32 center_freq, u32 bw)
+bool cfg80211_chandef_usable(struct wiphy *wiphy,
+                             const struct cfg80211_chan_def *chandef,
+                             u32 prohibited_flags)
 {
-        return cfg80211_secondary_chans_ok(wiphy, center_freq, bw,
-                                           IEEE80211_CHAN_DISABLED |
-                                           IEEE80211_CHAN_PASSIVE_SCAN |
-                                           IEEE80211_CHAN_NO_IBSS |
-                                           IEEE80211_CHAN_RADAR);
-}
+        struct ieee80211_sta_ht_cap *ht_cap;
+        struct ieee80211_sta_vht_cap *vht_cap;
+        u32 width, control_freq;
 
-bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
-                             struct cfg80211_chan_def *chandef)
-{
-        u32 width;
-        bool res;
+        if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+                return false;
 
-        trace_cfg80211_reg_can_beacon(wiphy, chandef);
+        ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
+        vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
 
-        if (WARN_ON(!cfg80211_chan_def_valid(chandef))) {
-                trace_cfg80211_return_bool(false);
-                return false;
-        }
+        control_freq = chandef->chan->center_freq;
 
         switch (chandef->width) {
-        case NL80211_CHAN_WIDTH_20_NOHT:
         case NL80211_CHAN_WIDTH_20:
+                if (!ht_cap->ht_supported)
+                        return false;
+        case NL80211_CHAN_WIDTH_20_NOHT:
                 width = 20;
                 break;
         case NL80211_CHAN_WIDTH_40:
                 width = 40;
+                if (!ht_cap->ht_supported)
+                        return false;
+                if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+                    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+                        return false;
+                if (chandef->center_freq1 < control_freq &&
+                    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+                        return false;
+                if (chandef->center_freq1 > control_freq &&
+                    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+                        return false;
                 break;
-        case NL80211_CHAN_WIDTH_80:
         case NL80211_CHAN_WIDTH_80P80:
+                if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
+                        return false;
+        case NL80211_CHAN_WIDTH_80:
+                if (!vht_cap->vht_supported)
+                        return false;
                 width = 80;
                 break;
         case NL80211_CHAN_WIDTH_160:
+                if (!vht_cap->vht_supported)
+                        return false;
+                if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
+                        return false;
                 width = 160;
                 break;
         default:
                 WARN_ON_ONCE(1);
-                trace_cfg80211_return_bool(false);
                 return false;
         }
 
-        res = cfg80211_check_beacon_chans(wiphy, chandef->center_freq1, width);
+        /* TODO: missing regulatory check on 80/160 bandwidth */
+
+        if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
+                                         width, prohibited_flags))
+                return false;
+
+        if (!chandef->center_freq2)
+                return true;
+        return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
+                                           width, prohibited_flags);
+}
+EXPORT_SYMBOL(cfg80211_chandef_usable);
+
+bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
+                             struct cfg80211_chan_def *chandef)
+{
+        bool res;
+
+        trace_cfg80211_reg_can_beacon(wiphy, chandef);
 
-        if (res && chandef->center_freq2)
-                res = cfg80211_check_beacon_chans(wiphy, chandef->center_freq2,
-                                                  width);
+        res = cfg80211_chandef_usable(wiphy, chandef,
+                                      IEEE80211_CHAN_DISABLED |
+                                      IEEE80211_CHAN_PASSIVE_SCAN |
+                                      IEEE80211_CHAN_NO_IBSS |
+                                      IEEE80211_CHAN_RADAR);
 
         trace_cfg80211_return_bool(res);
         return res;
diff --git a/net/wireless/core.h b/net/wireless/core.h
index a0c8decf6a47..6183a0d25b8b 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -483,12 +483,6 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                                enum nl80211_iftype iftype, int num);
 
-bool cfg80211_chan_def_valid(const struct cfg80211_chan_def *chandef);
-
-bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
-                                 u32 center_freq, u32 bandwidth,
-                                 u32 prohibited_flags);
-
 #define CFG80211_MAX_NUM_DIFFERENT_CHANNELS 10
 
 #ifdef CONFIG_CFG80211_DEVELOPER_WARNINGS
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d038fa45ecd1..eb0aa71a02b3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1420,63 +1420,33 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
         ht_cap = &rdev->wiphy.bands[chandef->chan->band]->ht_cap;
         vht_cap = &rdev->wiphy.bands[chandef->chan->band]->vht_cap;
 
-        if (!cfg80211_chan_def_valid(chandef))
+        if (!cfg80211_chandef_valid(chandef))
                 return -EINVAL;
 
         switch (chandef->width) {
         case NL80211_CHAN_WIDTH_20:
-                if (!ht_cap->ht_supported)
-                        return -EINVAL;
         case NL80211_CHAN_WIDTH_20_NOHT:
                 width = 20;
                 break;
         case NL80211_CHAN_WIDTH_40:
                 width = 40;
-                /* quick early regulatory check */
-                if (chandef->center_freq1 < control_freq &&
-                    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
-                        return -EINVAL;
-                if (chandef->center_freq1 > control_freq &&
-                    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
-                        return -EINVAL;
-                if (!ht_cap->ht_supported)
-                        return -EINVAL;
-                if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
-                    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
-                        return -EINVAL;
                 break;
         case NL80211_CHAN_WIDTH_80:
                 width = 80;
-                if (!vht_cap->vht_supported)
-                        return -EINVAL;
                 break;
         case NL80211_CHAN_WIDTH_80P80:
                 width = 80;
-                if (!vht_cap->vht_supported)
-                        return -EINVAL;
-                if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
-                        return -EINVAL;
                 break;
         case NL80211_CHAN_WIDTH_160:
                 width = 160;
-                if (!vht_cap->vht_supported)
-                        return -EINVAL;
-                if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
-                        return -EINVAL;
                 break;
         default:
                 return -EINVAL;
         }
 
-        if (!cfg80211_secondary_chans_ok(&rdev->wiphy, chandef->center_freq1,
-                                         width, IEEE80211_CHAN_DISABLED))
+        if (!cfg80211_chandef_usable(&rdev->wiphy, chandef,
+                                     IEEE80211_CHAN_DISABLED))
                 return -EINVAL;
-        if (chandef->center_freq2 &&
-            !cfg80211_secondary_chans_ok(&rdev->wiphy, chandef->center_freq2,
-                                         width, IEEE80211_CHAN_DISABLED))
-                return -EINVAL;
-
-        /* TODO: missing regulatory check on bandwidth */
 
         return 0;
 }
@@ -1841,7 +1811,7 @@ static inline u64 wdev_id(struct wireless_dev *wdev)
 static int nl80211_send_chandef(struct sk_buff *msg,
                                  struct cfg80211_chan_def *chandef)
 {
-        WARN_ON(!cfg80211_chan_def_valid(chandef));
+        WARN_ON(!cfg80211_chandef_valid(chandef));
 
         if (nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ,
                         chandef->chan->center_freq))