limit cambium beacon parser to more specific packets

Author: kkonradpl

tzsp-receiver.c

@@ -272,6 +272,8 @@ tzsp_receiver_packet(const uint8_t *packet,
 
         if(cambium_net_get_frequency(net_cambium))
             data->network->frequency = cambium_net_get_frequency(net_cambium) * 1000;
+        else if(channel)
+            data->network->frequency = (*channel * 5 + context->frequency_base) * 1000;
 
         cambium_net_free(net_cambium);
     }

tzsp/cambium.c

@@ -93,6 +93,10 @@ cambium_process_beacon(const uint8_t *data,
 
     context = calloc(sizeof(cambium_net_t), 1);
 
+    /* Only 0x08 seems to contain useful data */
+    if(data[1] != 0x08)
+        return context;
+
     for(i=CAMBIUM_BEACON_HEADER_LEN;
         i+CAMBIUM_BEACON_TAG_LEN <= len;
         i+=CAMBIUM_BEACON_TAG_LEN + data_len)