DLT_LOOP does have a link header, so tell pcap-filter so it can use it.

matthieu@ reported that asking tcpdump to look at ip or ip6 traffic
on a wg(4) interface caused all packets to be captured. this is
because pcap assumes that if your link type doesn't have a link
header then it is always ip or ip6 (which is weird anyway) and
captures everything.

there was already code to generate a filter for the DLT_LOOP link
header, it was just bypassed cos earlier code said that there wasn't
one.

debugged with and ok kn@

0 files changed, 0 insertions, 0 deletions