wifi: mac80211: refactor channel checks

To later introduce an override for VLP APs being allowed despite
NO-IR flags, which is somewhat similar in construction to being
allowed to monitor on disabled channels, refactor the code that
checks channel flags to have not a 'monitor' argument but a set
of 'permitting' flags that permit the operation without checking
for 'prohibited' flags.
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://msgid.link/20240523120945.3da28ded4a50.I90cffc633d0510293d511f60097dc75e719b55f0@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/chan.c

@@ -1145,7 +1145,8 @@ EXPORT_SYMBOL(cfg80211_chandef_dfs_cac_time);
 
 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
 					u32 center_freq, u32 bandwidth,
-					u32 prohibited_flags, bool monitor)
+					u32 prohibited_flags,
+					u32 permitting_flags)
 {
 	struct ieee80211_channel *c;
 	u32 freq, start_freq, end_freq;
@@ -1157,7 +1158,7 @@ static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
 		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c)
 			return false;
-		if (monitor && c->flags & IEEE80211_CHAN_CAN_MONITOR)
+		if (c->flags & permitting_flags)
 			continue;
 		if (c->flags & prohibited_flags)
 			return false;
@@ -1221,7 +1222,8 @@ static bool cfg80211_edmg_usable(struct wiphy *wiphy, u8 edmg_channels,
 
 bool _cfg80211_chandef_usable(struct wiphy *wiphy,
 			      const struct cfg80211_chan_def *chandef,
-			      u32 prohibited_flags, bool monitor)
+			      u32 prohibited_flags,
+			      u32 permitting_flags)
 {
 	struct ieee80211_sta_ht_cap *ht_cap;
 	struct ieee80211_sta_vht_cap *vht_cap;
@@ -1383,22 +1385,23 @@ bool _cfg80211_chandef_usable(struct wiphy *wiphy,
 
 	if (!cfg80211_secondary_chans_ok(wiphy,
 					 ieee80211_chandef_to_khz(chandef),
-					 width, prohibited_flags, monitor))
+					 width, prohibited_flags,
+					 permitting_flags))
 		return false;
 
 	if (!chandef->center_freq2)
 		return true;
 	return cfg80211_secondary_chans_ok(wiphy,
 					   MHZ_TO_KHZ(chandef->center_freq2),
-					   width, prohibited_flags, monitor);
+					   width, prohibited_flags,
+					   permitting_flags);
 }
 
 bool cfg80211_chandef_usable(struct wiphy *wiphy,
 			     const struct cfg80211_chan_def *chandef,
 			     u32 prohibited_flags)
 {
-	return _cfg80211_chandef_usable(wiphy, chandef, prohibited_flags,
-					false);
+	return _cfg80211_chandef_usable(wiphy, chandef, prohibited_flags, 0);
 }
 EXPORT_SYMBOL(cfg80211_chandef_usable);
 
@@ -1541,7 +1544,7 @@ static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
 		prohibited_flags = IEEE80211_CHAN_DISABLED;
 	}
 
-	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
+	res = _cfg80211_chandef_usable(wiphy, chandef, prohibited_flags, 0);
 
 	trace_cfg80211_return_bool(res);
 	return res;

net/wireless/core.h

@@ -494,7 +494,8 @@ bool cfg80211_wdev_on_sub_chan(struct wireless_dev *wdev,
 			       bool primary_only);
 bool _cfg80211_chandef_usable(struct wiphy *wiphy,
 			      const struct cfg80211_chan_def *chandef,
-			      u32 prohibited_flags, bool monitor);
+			      u32 prohibited_flags,
+			      u32 permitting_flags);
 
 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 {

net/wireless/nl80211.c

@@ -3347,7 +3347,7 @@ static int _nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 
 	if (!_cfg80211_chandef_usable(&rdev->wiphy, chandef,
 				      IEEE80211_CHAN_DISABLED,
-				      monitor)) {
+				      monitor ? IEEE80211_CHAN_CAN_MONITOR : 0)) {
 		NL_SET_ERR_MSG(extack, "(extension) channel is disabled");
 		return -EINVAL;
 	}