wifi: cfg80211: add cfg80211_get_iftype_ext_capa()

Add a helper function cfg80211_get_iftype_ext_capa() to
look up interface type-specific (extended) capabilities.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -5005,6 +5005,14 @@ struct wiphy_iftype_ext_capab {
 	u16 mld_capa_and_ops;
 };
 
+/**
+ * cfg80211_get_iftype_ext_capa - lookup interface type extended capability
+ * @wiphy: the wiphy to look up from
+ * @type: the interface type to look up
+ */
+const struct wiphy_iftype_ext_capab *
+cfg80211_get_iftype_ext_capa(struct wiphy *wiphy, enum nl80211_iftype type);
+
 /**
  * struct cfg80211_pmsr_capabilities - cfg80211 peer measurement capabilities
  * @max_peers: maximum number of peers in a single measurement

net/wireless/util.c

@@ -2490,3 +2490,17 @@ int cfg80211_remove_virtual_intf(struct cfg80211_registered_device *rdev,
 
 	return rdev_del_virtual_intf(rdev, wdev);
 }
+
+const struct wiphy_iftype_ext_capab *
+cfg80211_get_iftype_ext_capa(struct wiphy *wiphy, enum nl80211_iftype type)
+{
+	int i;
+
+	for (i = 0; i < wiphy->num_iftype_ext_capab; i++) {
+		if (wiphy->iftype_ext_capab[i].iftype == type)
+			return &wiphy->iftype_ext_capab[i];
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(cfg80211_get_iftype_ext_capa);