Date: Wed, 24 Jan 2001 15:01:38 -0800 (PST) From: Luigi Rizzo <rizzo@aciri.org> To: agoodloe@gradient.cis.upenn.edu (Alwyn Goodloe) Cc: rizzo@aciri.org, hackers@FreeBSD.ORG Subject: Re: Divert Sockets & Fragmentation Message-ID: <200101242301.f0ON1cX21729@iguana.aciri.org> In-Reply-To: <Pine.SOL.4.21.0101241755480.2862-100000@gradient.cis.upenn.edu> from Alwyn Goodloe at "Jan 24, 2001 6: 0:10 pm"
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> I was originally diverting udp packets heading to a particular port then > I flushed the ipfw and tried: > > ipfw add 60000 divert 4422 ip all from any to any in > and still no packets are received by recvfrom(). Would the port numbers > matter for this case. probably not but better check if you have any former rule which matches fragments luigi > Alwyn > agoodloe@gradient.cis.upenn.edu > > > > > > On Wed, 24 Jan 2001, Luigi Rizzo wrote: > > > it depends on what template do you use for matching. > > the firewall acts before reassembly, so for the fragments you will > > not be able to see the port numbers. > > > > cheers > > luigi > > > > > I have been using divert sockets for a while sending small (< MTU) UDP > > > packets and everything worked fine. Now that the UDP packets are larger > > > (>MTU = 1500) and hence fragmentation is taking place there seems to be a > > > problem. tcpdump tells me that the fragmented packets arrive but it seems > > > that they are never diverted. I say this because after they are received > > > recvfrom () never gets the packet. I've done things like play with the > > > nbytes field of the recvfrom() fn. without any success. Any > > > suggestions, I'm sure its something stupid. > > > > > > > > > Alwyn > > > agoodloe@gradient.cis.upenn.edu > > > > > > > > > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > > with "unsubscribe freebsd-hackers" in the body of the message > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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