[PATCH] Runt frames dropped under RX checksum in hamachi.c

Pete Wyckoff wyckoff@ca.sandia.gov
Fri Mar 10 17:57:12 2000


wyckoff@ca.sandia.gov said:
> Tony Caola brought to my attention the fact that my receive checksum
> enabling changes to the hamachi driver cause some packets to be dropped
> due to invalid checksum.

P.S.  The only reason this was noticed at all is that Tony was trying to
ssh in from a Sun over the gige port.  Linux tacks on plenty of TCP
header options (wscale,mss,sackOK on SYN, and timestamp on all) so that
under-64-byte packets are never generated.  The Sun was producing
sub-64-byte byte SYN packets and those were getting tossed.

Unless you were playing with turning off tcp_timestamps, or coming in
from foreign systems, you would never trigger this bug.

		-- Pete
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