Date: Tue, 5 Aug 2003 20:29:45 -0400 From: Barney Wolff <barney@databus.com> To: Edwin Groothuis <edwin@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: bpf, ipfw and before-and-after Message-ID: <20030806002945.GA57865@pit.databus.com> In-Reply-To: <20030805235411.GA558@k7.mavetju> References: <20030805133922.GA7713@k7.mavetju> <20030805143100.GA52099@pit.databus.com> <20030805235411.GA558@k7.mavetju>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Aug 06, 2003 at 09:54:11AM +1000, Edwin Groothuis wrote: > On Tue, Aug 05, 2003 at 10:31:01AM -0400, Barney Wolff wrote: > > Seems to me that with ipfw logging and tcpdump packet selection this > > is largely a non-issue. We should be wary of adding complexity to > > what's already at the limits of human comprehension. > > Could you explain that first line a little bit more verbose? ipfw can log packets, giving source ip/port, dest ip/port, proto and interface which is at least some of the info that tcpdump would supply. tcpdump can take quite complex selection criteria to determine whether to log a packet. So your complaint that tcpdump logs stuff that ipfw is going to drop can be substantially mitigated. > About the second one, given the fact that I could find out how it > works (more or less) and where to add the statements, makes me think > that despite the complexity of the thing being achieved, the > implementation in the code is pretty neat and structured. The issue is not that the addition would be complex, but that every addition to a system already very complex must be carefully weighed against the claimed benefits. Does the expression "creeping featurism" sound familiar? Every feature of the Win32 API, OS/360 and the US Federal Tax Code was added because somebody thought it was a good idea. "Perfection in design is achieved not when there is nothing left to add, but when there is nothing left to take away." -- Barney Wolff http://www.databus.com/bwresume.pdf I'm available by contract or FT, in the NYC metro area or via the 'Net.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030806002945.GA57865>