Date: Wed, 05 Mar 2003 14:29:54 +0000 From: Mark Murray <mark@grondar.org> To: Terry Lambert <tlambert2@mindspring.com> Cc: freebsd-net@FreeBSD.ORG, freebsd-current@FreeBSD.ORG Subject: Re: Removal of netns - politically correct version Message-ID: <200303051429.h25ETsIg047004@grimreaper.grondar.org> In-Reply-To: Your message of "Wed, 05 Mar 2003 04:32:23 PST." <3E65EE57.BBD230B4@mindspring.com>
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Terry Lambert writes: > Let' start wth the libalias/natd incremental checksum update code; > the code is based on RFC1141, instead of RFC1624. As a result, > it get updated incorrectly occasionally, because it's using two's > complement instead of one's complement math. Per RFC1642: > > RFC 1141 yields an updated header checksum of -0 when it should be > +0. This is because it assumed that one's complement has a > distributive property, which does not hold when the result is 0 (see > derivation of [Eqn. 2]). > > People see this as hands on FTP installs, etc., going through > FreeBSD based NAT's. > > It's very obvious ad easy to repeat: > > 1) Put a printf in tcp_input.c that compalins when the > checksum is incorect. > > 2) Do a CVSup from that machine through a FreeBSD NAT > > > How long can this remain unfixed before the code is diked out, > and the checksum is recalculated fully, instead? Terry, you sound rather foolish when you argue like this. This is semantic tomfoolery and off topic. End of thread. M -- Mark Murray iumop ap!sdn w,I idlaH To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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