trim the FCS off Ethernet packets before sending them up the stack.

Jurjen Oskam on tech@ found that ure in a veb caused these extra
fcs bytes to be transmitted by other veb members. the extra bytes
aren't a problem usually because our network stack ignores them if
they're present, eg, the ip stack reads an ip packet length and
trims bytes in an mbuf if there's more. bridge(4) masked this problem
because it always parses IP packets going over the bridge and trims
them like the IP stack before pushing them out another port.

veb(4) generally just moves packets around based on the Ethernet
header, by default it doesn't look too deeply into packets, which
is why this issue popped out.

it is more correct for ure to just not pass the fcs bytes up.

ok jmatthew@ kevlo@

0 files changed, 0 insertions, 0 deletions