madwifi: recognize hidden essid with length=1 containing a nullbyte

SVN-Revision: 11793

package/madwifi/patches/356-hidden_ssid.patch

@@ -0,0 +1,38 @@
+This patch fixes the detection of hidden SSIDs as transmitted
+by some cisco systems.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
+--- a/net80211/ieee80211_scan_sta.c
++++ b/net80211/ieee80211_scan_sta.c
+@@ -209,6 +209,19 @@
+ 		ieee80211_saveie(iep, ie);
+ }
+ 
++
++static inline int is_empty_ssid(u_int8_t *ssid)
++{
++	if (!ssid)
++		return 1;
++	if (ssid[1] == 0)
++		return 1;
++	if ((ssid[1] == 1) && (ssid[2] == 0))
++		return 1;
++	return 0;
++}
++
++
+ /*
+  * Process a beacon or probe response frame; create an
+  * entry in the scan cache or update any previous entry.
+@@ -252,8 +265,8 @@
+ 	ise = &se->base;
+ 
+ 	/* XXX ap beaconing multiple ssid w/ same bssid */
+-	if (sp->ssid[1] != 0 &&
+-	    (ISPROBE(subtype) || ise->se_ssid[1] == 0))
++	if (!is_empty_ssid(sp->ssid) &&
++	    (ISPROBE(subtype) || is_empty_ssid(ise->se_ssid)))
+ 		memcpy(ise->se_ssid, sp->ssid, 2 + sp->ssid[1]);
+ 
+ 	memcpy(ise->se_rates, sp->rates,