Date: Wed, 10 Jun 2009 17:52:10 -0400 From: John Baldwin <jhb@freebsd.org> To: Robert Watson <rwatson@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r193941 - head/sys/netinet Message-ID: <200906101752.11336.jhb@freebsd.org> In-Reply-To: <alpine.BSF.2.00.0906102051570.45017@fledge.watson.org> References: <200906101827.n5AIRFoR022115@svn.freebsd.org> <alpine.BSF.2.00.0906102051570.45017@fledge.watson.org>
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On Wednesday 10 June 2009 3:52:31 pm Robert Watson wrote: > > On Wed, 10 Jun 2009, John Baldwin wrote: > > > Change a few members of tcpcb that store cached copies of ticks to be ints > > instead of unsigned longs. This fixes a few overflow edge cases on 64-bit > > platforms. Specifically, if an idle connection receives a packet shortly > > before 2^31 clock ticks of uptime (about 25 days with hz=1000) and the keep > > alive timer fires after 2^31 clock ticks, the keep alive timer will think > > that the connection has been idle for a very long time and will immediately > > drop the connection instead of sending a keep alive probe. > > > > Reviewed by: silby, gnn, lstewart > > MFC after: 1 week > > That's pretty subtle even as TCP bugs go, nice work :-). More of the credit goes to gnn@ and my co-workers. I had told gnn@ to not worry about overflow about a week ago because I had just assumed (incorrectly) that 'ticks' and 't_rcvtime' were the same size. :-/ -- John Baldwin
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