Re: [libvirt] [PATCH] Add support for DNS TXT records

Hi Laine, thanks for your reply. Comments inline... On 03/25/2011 10:02 PM, Laine Stump wrote: > I haven't had time yet to look at the code in detail, but thought I > should send this preliminary commentary. > > On 03/24/2011 09:58 AM, Michal Novotny wrote: >> Hi, >> this is the patch to add DNS TXT record support to libvirt networking >> driver since this is feature that's supported by DNSMasq that's being >> used by the bridge driver. >> >> Maybe you fail to understand the reasons why to implement such a feature >> however it's a good thing IMHO since user could provide some information >> in the DNS TXT record headers. > As a matter of fact, I think that not only is this useful, but > configuring other capabilities presented by dnsmasq would be good. I > think you'll find a kindred spirit in Paweł Krześniak, who was also > wanting some other dnsmasq capabilities exposed (I forget which now). Well, I have to agree that there are some options/capabilities that would be good to be configurable.

>> The headers are, of course, configurable >> in the network XML description and the idea got to me when I was reading >> an article about DKIM (DomainKeys Identified Mail) since it's using TXT >> records in the DNS to provide the public keys. This inspired me to >> implement the DNS TXT record support to libvirt bridge driver to allow >> users expose some information to the guest if they want to do so etc. >> >> Limitations: >> - Records names and values containing space (' ') arguments are altered >> to change spaces to underscores ('_'). This is because of proper >> argument handling when spawning dnsmasq. > > Is this really necessary? We're not talking about a shell commandline > here, but an array of null terminated strings. If it's a restriction > placed by dnsmasq itself, then we should just disallow ' ' during > parsing rather than silently changing it, to avoid surprises. Well, that's the reason since if we quote this we can't use dig to dig it correctly without the quotes. This was simply the way to disallow ' ' by changing it to underscores since I didn't want the definition to fail because of this.