unbound looks like an excellent choice, thanks for pointing it out.
On Tue, Aug 08, 2017 at 08:09:28PM +0000, Mark Michelson wrote: > In a project I worked on previously, we used unbound [1] for async DNS, and > it worked well for our needs. We liked that DNSSEC was supported out of the > box. If you're talking about just doing A/AAAA lookups, that's also > supported out of the box. If you want to do fancier things (NAPTR or SRV), > then you'll have to parse the DNS results yourself. And as for the > licensing, it's BSD [2] licensed. > > Mark Michelson > > [1] https://www.unbound.net/ > [2] http://unbound.nlnetlabs.nl/svn/trunk/LICENSE > > On Tue, Aug 8, 2017 at 2:49 PM Ben Pfaff <b...@ovn.org> wrote: > > > On Tue, Aug 08, 2017 at 02:59:21PM -0400, Lance Richardson wrote: > > > > From: "Ben Pfaff" <b...@ovn.org> > > > > To: d...@openvswitch.org > > > > Sent: Tuesday, August 8, 2017 2:43:17 PM > > > > Subject: [ovs-dev] DNS support options > > > > > > > > Open vSwitch currently supports only IP addresses for specifying > > > > OpenFlow and OVSDB remotes. It would be nice to support DNS names. > > > > Open vSwitch can't afford to let DNS resolution block processing, so it > > > > needs some way to resolve DNS asynchronously. I've come up with the > > > > following solutions so far: > > > > > > > > * Implement it ourselves using threads. Probably, this would > > be > > > > a single worker thread that loops through calls to > > > > getaddrinfo(). > > > > > > > > * glibc has getaddrinfo_a(), an asynchronous version of > > > > getaddrinfo(). *BSD and Windows do not have this function, > > so > > > > we would still need to implement it ourselves (probably using > > > > threads) if we adopted this approach, so it might be more > > work > > > > than the first solution. > > > > > > > > * Use an external asynchronous DNS library. GNU adns looks > > like > > > > a good choice: http://www.chiark.greenend.org.uk/~ian/adns/. > > > > It has a port to Windows but I don't know whether it's > > > > up-to-date. > > > > > > > > > > With adns_beforepoll()/adns_afterpoll(), it looks like adns might be easy > > > to integrate on top of lib/poll-loop.c. Not requiring a separate thread > > > seems like a plus. > > > > Oops, I just realized that adns is GPL'd, which means that linking it > > against OVS would force OVS to be GPL'd, so it's probably not a good > > choice. > > > > Other possible choices: > > > > - c-ares (https://c-ares.haxx.se/). Main disadvantage seems to > > be that it's very "select" oriented. > > > > - UDNS (http://www.corpit.ru/mjt/udns.html). May not be well > > maintained--last release in 2014. Does not fall back to TCP > > if necessary. Port to Windows exists, don't know whether it's > > up-to-date. > > _______________________________________________ > > dev mailing list > > d...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
