fix detection of 802.11a/b protocols

iptest/iptest.cpp

@@ -42,7 +42,7 @@ int main(int argc, char *argv[]) {
 
   //interface.deleteAddress("1.1.1.5/29");
 
-  Wireless wi("wlp0s11u1");
+  Wireless wi("wlp3s0");
 
   QList<BandInfo> bands = wi.bandMap();
 
@@ -81,12 +81,13 @@ int main(int argc, char *argv[]) {
       std::cout << "is channel 165 supported? " << (wi.channelSupported(165) ? "yes" : "no") << std::endl;
       std::cout << "is frequency 2.437GHz supported? " << (wi.frequencySupported(2437) ? "yes" : "no") << std::endl;
       std::cout << "is frequency 5.825GHz supported? " << (wi.frequencySupported(5825) ? "yes" : "no") << std::endl;
-      std::cout << "all channels:";
     }else{
       std::cout << "no channels supported" << std::endl;
     }
   }
 
+  std::cout << "all channels:";
+
   foreach(int chan, wi.allChannels()) {
     std::cout << " " << chan;
   }

wireless.cpp

@@ -439,7 +439,7 @@ int Wireless::nl80211_freqlist_cb(struct nl_msg *msg, void *arg) {
       }
 
       if(!((band.protocols & PROTOCOL_80211_B) == PROTOCOL_80211_B)) {
-        if(info.chan >= 1) { // first 2.4GHz channel
+        if(info.chan <= 14) { // last 2.4GHz channel
           band.protocols = static_cast<Protocols>(band.protocols | PROTOCOL_80211_B);
           band.band = static_cast<Bands>(band.band | BAND_2GHZ);
         }