spkt: check for minimum common header length (#1987)
spkt: check for minimum common header length (#1987)


klausman/scion,netsec-ethz/scion,klausman/scion,klausman/scion,Oncilla/scion,Oncilla/scion,netsec-ethz/scion,klausman/scion,netsec-ethz/scion,netsec-ethz/scion,Oncilla/scion,Oncilla/scion,klausman/scion