Bugfix: don't send packets if they are shorter than the link layer header length

tools/sky/uip6-bridge/sicslow_ethernet.c

@@ -279,6 +279,7 @@ void mac_ethernetToLowpan(uint8_t * ethHeader)
   }
 
   //Remove header from length before passing onward
+  if(uip_len > UIP_LLH_LEN) {
     uip_len -= UIP_LLH_LEN;
     
     //Some IP packets have link layer in them, need to change them around!
@@ -292,6 +293,7 @@ void mac_ethernetToLowpan(uint8_t * ethHeader)
       tcpip_output(destAddrPtr);
       /* 	  rndis_stat.txok++; */
     }
+  }
 
   uip_len = 0;