[dnsdist] DnsDist Firefox Issue

Wed Sep 30 10:40:56 UTC 2015

https://github.com/PowerDNS/pdns/commit/bde3ab9654b1a33a6a250bf053c8f8ba044f67e8
has the fix, thank you!

	Bert

On Wed, Sep 30, 2015 at 01:31:55PM +0300, Burak Ozalp wrote:
> Dear Bert;
> 
> I double-check pcap's and you are right. When dnsdist is closed, RA
> bit equals 1. However, when i start dnsdist service, RA bit equals
> 0.
> 
> Probably there is some bug about this issue.
> 
> Your welcome, thank you for your interest :)
> 
> Best Regards
> Burak Özalp
> 
> Alinti bert hubert <bert.hubert at netherlabs.nl>
> 
> >On Tue, Sep 29, 2015 at 11:18:15AM +0300, Burak Ozalp wrote:
> >>Hi Bert,
> >>
> >>Actually, i solved the whole issue! The point is that i checked the
> >>pcap files and understand that RA bit (RA, Recursion Available bit )
> >>differs.
> >
> >Burak, thank you for investigating this!
> >
> >I'm very confused now, the RA bit should've been set already!
> >
> >Does your pcap show that dnsdist *dropped* the RA bit perhaps? Or we forgot
> >to set it on the TC=1 response? That might well be it.
> >
> >Can you verify that assumption?
> >
> >Thanks!
> >
> >	Bert
> >
> >
> >>
> >>Then i changed the dnsdist-lua.cc first and add the following lines
> >>to add setRA functionality to dnsdist;
> >>
> >>  g_lua.registerFunction<void(dnsheader::*)(bool)>("setRA",
> >>[](dnsheader& dh, bool v) {
> >>      dh.ra=v;
> >>    });
> >>
> >>then i add a single line to dnsdistconf.lua ( 	dh:setRA(true) )
> >>
> >>Finally, it worked for all browsers(Chrome,Firefox,Opera etc.)
> >>without any problems.
> >>
> >>I think if you add setRA function to master branch and create repos
> >>for rpm, it would be great!
> >>
> >>Thanks.
> >>
> >>Best Regards
> >>Burak Ozalp
> >>
> >>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>
> >>>On Fri, Sep 04, 2015 at 01:25:42PM +0300, Burak Ozalp wrote:
> >>>>I actually test in nearly all browsers, including
> >>>>Vivaldi-Opera-Firefox version 38, and all reject TCP connections. Is
> >>>>it possible that we do something wrong in lua script?
> >>>
> >>>I checked your PCAP, everything is perfect there. I think the browsers are
> >>>just not cooperating, or perhaps a firewall is preventing them
> >>from reaching
> >>>your server on TCP?
> >>>
> >>>	Bert
> >>>
> >>>>
> >>>>addLocal("0.0.0.0:53")
> >>>>newServer{address="8.8.8.8"}
> >>>>
> >>>>addAction(MaxQPSIPRule(5000), DropAction())
> >>>>
> >>>>function blockFilter(remote, qname, qtype, dh)
> >>>>        dh:setTC(true)
> >>>>        dh:setQR(true)
> >>>>        return false
> >>>>end
> >>>>
> >>>>Thanks!
> >>>>
> >>>>Best Regards
> >>>>
> >>>>Burak Özalp
> >>>>
> >>>>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>>>
> >>>>>Burak,
> >>>>>
> >>>>>Thank you, but this is the place to report your issues:
> >>>>>
> >>>>>https://bugzilla.mozilla.org/enter_bug.cgi
> >>>>>and
> >>>>>https://support.google.com/chrome/answer/95315?hl=en
> >>>>>
> >>>>>We sadly can't support all software products on the planet
> >>from dnsdist ;-)
> >>>>>
> >>>>>	Bert
> >>>>>
> >>>>>
> >>>>>On Fri, Sep 04, 2015 at 09:23:38AM +0300, Burak Ozalp wrote:
> >>>>>>Hi Bert
> >>>>>>
> >>>>>>Thank you for your interest. Firefox and Chrome DNS operations's
> >>>>>>pcap files are attached.
> >>>>>>
> >>>>>>Best Regards
> >>>>>>Burak Ozalp
> >>>>>>
> >>>>>>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>>>>>
> >>>>>>>On Thu, Sep 03, 2015 at 02:24:28PM +0300, Burak Ozalp wrote:
> >>>>>>>>Actually, it only works for Ubuntu-Chrome.. In Windows neither
> >>>>>>>>Chrome nor Internet Explorer works with these configuration. What
> >>>>>>>>could be the reason of this situation ?
> >>>>>>>
> >>>>>>>Hi Burak,
> >>>>>>>
> >>>>>>>We estimate that this is an issue that Mozilla and Google might
> >>>>>>need to take
> >>>>>>>a look at.
> >>>>>>>
> >>>>>>>We asked a friend at Mozilla and he suggests you file a
> >>very detailed bug
> >>>>>>>with them, including a tcpdump that shows what happens (UDP query, TC=1
> >>>>>>>response, no followup).
> >>>>>>>
> >>>>>>>On the dns-operations list we also discussed this issue you reported,
> >>>>>>>https://lists.dns-oarc.net/pipermail/dns-operations/2015-September/013637.html
> >>>>>>>where we learned that Firedox 38 at least on one platform
> >>does the right
> >>>>>>>thing.
> >>>>>>>
> >>>>>>>	Bert
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>
> >>>>>>>>Best Regards
> >>>>>>>>Burak Özalp
> >>>>>>>>
> >>>>>>>>Alinti Burak Ozalp <burak.ozalp at metu.edu.tr>
> >>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>Yes! It works. When we try with the Chrome Browser it responds
> >>>>>>>>>with the TC-bit set and then it automatically retries TCP(looks
> >>>>>>>>>great) . However, when we try with Firefox Browser, it only
> >>>>>>>>>returns the response and not try with TCP.
> >>>>>>>>>
> >>>>>>>>>This is our related configurations;
> >>>>>>>>>
> >>>>>>>>>glibc vesion : 2.13-1
> >>>>>>>>>Kernel version : 3.2.0-68-generic
> >>>>>>>>>Firefox version: 40.0.3
> >>>>>>>>>Chrome version: 43.0.2357.65
> >>>>>>>>>--
> >>>>>>>>>
> >>>>>>>>>Best Regards
> >>>>>>>>>Burak Ozalp
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>>>>>>>>
> >>>>>>>>>>On Wed, Sep 02, 2015 at 03:52:11PM +0300, Burak Ozalp wrote:
> >>>>>>>>>>>Our problem is that we don't know the source address.
> >>Our aim is the
> >>>>>>>>>>>defence against DDos Attacks, we should limit for all different
> >>>>>>>>>>>IP's. As a result, when an attacker attacks our server, we need to
> >>>>>>>>>>>not drop innocent requests.
> >>>>>>>>>>
> >>>>>>>>>>Ok, then do:
> >>>>>>>>>>
> >>>>>>>>>>addAction(MaxQPSIPRule(5), DropAction())
> >>>>>>>>>>
> >>>>>>>>>>On the latest packages. Limits each individual IP to 5
> >>>>QPS, drops beyond
> >>>>>>>>>>that.
> >>>>>>>>>>
> >>>>>>>>>>	Bert
> >>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>Best Regards
> >>>>>>>>>>>Burak Ozalp
> >>>>>>>>>>>
> >>>>>>>>>>>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>>>>>>>>>>
> >>>>>>>>>>>>On Wed, Sep 02, 2015 at 02:31:33PM +0300, Burak Ozalp wrote:
> >>>>>>>>>>>>>Hi Bert;
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>AddQPS is the best option for us. Is it possible to apply
> >>>>>>>>>>>>>addQPSLimit for individual IP's ?
> >>>>>>>>>>>>
> >>>>>>>>>>>>Yes, as outlined in the documentation ->
> >>>>>>>>>>>>https://github.com/PowerDNS/pdns/blob/master/pdns/README-dnsdist.md#per-domain-or-subnet-qps-limiting
> >>>>>>>>>>>>
> >>>>>>>>>>>>You can add as many subnets as you want, or individual IPs etc.
> >>>>>>>>>>>>
> >>>>>>>>>>>>Good luck!
> >>>>>>>>>>>>
> >>>>>>>>>>>>	Bert
> >>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Best Regards
> >>>>>>>>>>>>>Burak Ozalp
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Alinti bert hubert <bert.hubert at netherlabs.nl>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>>On Wed, Sep 02, 2015 at 02:08:38PM +0300, Burak Ozalp wrote:
> >>>>>>>>>>>>>>>With the current version of RPM i get no error. However,
> >>>>>>>>>>>>>>>addAction(MaxQPSIPRule(5), NoRecurseAction()) ,
> >>>>didn't do its job.
> >>>>>>>>>>>>>>>Should we use both addQPSLimit and addAction together
> >>>>for limiting
> >>>>>>>>>>>>>>>indivual IP to 5 qps?
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>No, addQPSLimit alone is fine. The addAction is only if you
> >>>>>>>>>>>>>want to drop the
> >>>>>>>>>>>>>>RD-bit for traffic that exceeds the QPS limit.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>	Bert
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>_______________________________________________
> >>>>>>>>>>>>>dnsdist mailing list
> >>>>>>>>>>>>>dnsdist at mailman.powerdns.com
> >>>>>>>>>>>>>http://mailman.powerdns.com/mailman/listinfo/dnsdist
> >>>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>_______________________________________________
> >>>>>>>>>>>dnsdist mailing list
> >>>>>>>>>>>dnsdist at mailman.powerdns.com
> >>>>>>>>>>>http://mailman.powerdns.com/mailman/listinfo/dnsdist
> >>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>_______________________________________________
> >>>>>>>>>dnsdist mailing list
> >>>>>>>>>dnsdist at mailman.powerdns.com
> >>>>>>>>>http://mailman.powerdns.com/mailman/listinfo/dnsdist
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>_______________________________________________
> >>>>>>>>dnsdist mailing list
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> >>>>>>>>http://mailman.powerdns.com/mailman/listinfo/dnsdist
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>>_______________________________________________
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> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>>_______________________________________________
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> >>>
> >>
> >>
> >>
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> >
> 
> 
> 
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