cfg80211: add more flexible BSS lookup

Add a more flexible BSS lookup function so that mac80211 or
other drivers can actually use this for getting the BSS to
connect to.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/cfg80211.h

@@ -785,7 +785,17 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 				      struct ieee80211_channel *channel,
 				      const u8 *bssid,
-				      const u8 *ssid, size_t ssid_len);
+				      const u8 *ssid, size_t ssid_len,
+				      u16 capa_mask, u16 capa_val);
+static inline struct cfg80211_bss *
+cfg80211_get_ibss(struct wiphy *wiphy,
+		  struct ieee80211_channel *channel,
+		  const u8 *ssid, size_t ssid_len)
+{
+	return cfg80211_get_bss(wiphy, channel, NULL, ssid, ssid_len,
+				WLAN_CAPABILITY_IBSS, WLAN_CAPABILITY_IBSS);
+}
+
 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
 				       struct ieee80211_channel *channel,
 				       const u8 *meshid, size_t meshidlen,

net/wireless/scan.c

@@ -116,9 +116,12 @@ static bool is_bss(struct cfg80211_bss *a,
 {
 	const u8 *ssidie;
 
-	if (compare_ether_addr(a->bssid, bssid))
+	if (bssid && compare_ether_addr(a->bssid, bssid))
 		return false;
 
+	if (!ssid)
+		return true;
+
 	ssidie = find_ie(WLAN_EID_SSID,
 			 a->information_elements,
 			 a->len_information_elements);
@@ -199,14 +202,17 @@ static int cmp_bss(struct cfg80211_bss *a,
 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 				      struct ieee80211_channel *channel,
 				      const u8 *bssid,
-				      const u8 *ssid, size_t ssid_len)
+				      const u8 *ssid, size_t ssid_len,
+				      u16 capa_mask, u16 capa_val)
 {
 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 	struct cfg80211_internal_bss *bss, *res = NULL;
 
 	spin_lock_bh(&dev->bss_lock);
 
 	list_for_each_entry(bss, &dev->bss_list, list) {
+		if ((bss->pub.capability & capa_mask) != capa_val)
+			continue;
 		if (channel && bss->pub.channel != channel)
 			continue;
 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {