Date: Mon, 19 Jul 1999 22:52:42 -0600 (MDT) From: David G Andersen <danderse@cs.utah.edu> To: mrcpu@internetcds.com (Jaye Mathisen) Cc: hackers@FreeBSD.ORG Subject: Re: tee option on ipfw? Message-ID: <199907200452.WAA15557@lal.cs.utah.edu> In-Reply-To: <Pine.BSF.4.10.9907181540560.357-100000@schizo.cdsnet.net> from "Jaye Mathisen" at Jul 18, 99 03:42:19 pm
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The 'tee' behavior can be pretty easily emulated, however.
a) use bpfilter - it automatically does a copy type thing.
b) Use a little divert socket program which simply does:
len = recvfrom(divert_socket, packetbuf, sizeof(packetbuf),
0, (struct sockaddr *)&from, &fromlen);
sendto(divert_socket, packetbuf, len, 0,
(struct sockaddr *)&from, fromlen);
do_whatever_stuff_you_want();
Option a will, of course, be faster, since it doesn't involve a copy to
userspace before allowing the packet to continue its normal path. The tee
option would do the same thing, if and when.
-Dave
Lo and behold, Jaye Mathisen once said:
>
>
>
> The man page says the tee option on ipfw is not yet supported.
>
> I'm wondering if that is still the case as of 3.2-stable, or if the doc is
> just out of date.
>
> I would like to make a copy of incoming UDP packets to a specific port for
> some testing. tee seems like an easy way to go.
>
>
>
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--
work: danderse@cs.utah.edu me: angio@pobox.com
University of Utah CS Department http://www.angio.net/
"If you haul a geek up a crack, you will bloody their fingers for a day...
If you teach a geek to climb, you will bloody their fingers for life."
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