cfg80211: don't allow drivers to unset NL80211_FEATURE_SCAN_FLUSH

As the flag is entirely implemented in cfg80211, it should
have been a global feature flag (which I believe didn't
exist at the time). However, there's no reason to allow
drivers to unset the flag, so don't allow it and remove
the validation of NL80211_SCAN_FLAG_FLUSH.

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

2 files changed, 6 insertions, 10 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index aff959e5a1b3..9dca0925a1a9 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -357,8 +357,6 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
         rdev->wiphy.rts_threshold = (u32) -1;
         rdev->wiphy.coverage_class = 0;
 
-        rdev->wiphy.features = NL80211_FEATURE_SCAN_FLUSH;
-
         return &rdev->wiphy;
 }
 EXPORT_SYMBOL(wiphy_new);
@@ -566,6 +564,8 @@ int wiphy_register(struct wiphy *wiphy)
         /* check and set up bitrates */
         ieee80211_set_bitrate_flags(wiphy);
 
+        rdev->wiphy.features |= NL80211_FEATURE_SCAN_FLUSH;
+
         rtnl_lock();
         res = device_add(&rdev->wiphy.dev);
         if (res) {
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e2bb4276af1a..1ad11de6dd2f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5342,10 +5342,8 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
         if (info->attrs[NL80211_ATTR_SCAN_FLAGS]) {
                 request->flags = nla_get_u32(
                         info->attrs[NL80211_ATTR_SCAN_FLAGS]);
-                if (((request->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
-                     !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) ||
-                    ((request->flags & NL80211_SCAN_FLAG_FLUSH) &&
-                     !(wiphy->features & NL80211_FEATURE_SCAN_FLUSH))) {
+                if ((request->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
+                    !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) {
                         err = -EOPNOTSUPP;
                         goto out_free;
                 }
@@ -5585,10 +5583,8 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
         if (info->attrs[NL80211_ATTR_SCAN_FLAGS]) {
                 request->flags = nla_get_u32(
                         info->attrs[NL80211_ATTR_SCAN_FLAGS]);
-                if (((request->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
-                     !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) ||
-                    ((request->flags & NL80211_SCAN_FLAG_FLUSH) &&
-                     !(wiphy->features & NL80211_FEATURE_SCAN_FLUSH))) {
+                if ((request->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
+                    !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) {
                         err = -EOPNOTSUPP;
                         goto out_free;
                 }