mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-11-04 20:31:13 +00:00
f69a6b987d
In commitf386825we began adding the options --domain-needed --local=/$mydomain/ to all dnsmasq commandlines with the stated reason of preventing forwarding of DNS queries for names that weren't fully qualified domain names ("FQDN", i.e. a name that included some "."s and a domain name). This was later changed to domain-needed local=/$mydomain/ when we moved the options from the dnsmasq commandline to a conf file. The original patch on the list, and discussion about it, is here: https://www.redhat.com/archives/libvir-list/2012-August/msg01594.html When a domain name isn't specified (mydomain == ""), the addition of "domain-needed local=//" will prevent forwarding of domain-less requests to the virtualization host's DNS resolver, but if a domain *is* specified, the addition of "local=/domain/" will prevent forwarding of any requests for *qualified* names within that domain that aren't resolvable by libvirt's dnsmasq itself. An example of the problems this causes - let's say a network is defined with: <domain name='example.com'/> <dhcp> .. <host mac='52:54:00:11:22:33' ip='1.2.3.4' name='myguest'/> </dhcp> This results in "local=/example.com/" being added to the dnsmasq options. If a guest requests "myguest" or "myguest.example.com", that will be resolved by dnsmasq. If the guest asks for "www.example.com", dnsmasq will not know the answer, but instead of forwarding it to the host, it will return NOT FOUND to the guest. In most cases that isn't the behavior an admin is looking for. A later patch (commit4f595ba) attempted to remedy this by adding a "forwardPlainNames" attribute to the <dns> element. The idea was that if forwardPlainNames='yes' (default is 'no'), we would allow unresolved names to be forwarded. However, that patch was botched, in that it only removed the "domain-needed" option when forwardPlainNames='yes', and left the "local=/mydomain/". Really we should have been just including the option "--domain-needed --local=//" (note the lack of domain name) regardless of the configured domain of the network, so that requests for names without a domain would be treated as "local to dnsmasq" and not forwarded, but all others (including those in the network's configured domain) would be forwarded. We also shouldn't include *either* of those options if forwardPlainNames='yes'. This patch makes those corrections. This patch doesn't remedy the fact that default behavior was changed by the addition of this feature. That will be handled in a subsequent patch.
16 lines
443 B
Plaintext
16 lines
443 B
Plaintext
##WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
|
|
##OVERWRITTEN AND LOST. Changes to this configuration should be made using:
|
|
## virsh net-edit default
|
|
## or other application using the libvirt API.
|
|
##
|
|
## dnsmasq conf file created by libvirt
|
|
strict-order
|
|
domain=example.com
|
|
expand-hosts
|
|
domain-needed
|
|
local=//
|
|
except-interface=lo
|
|
bind-dynamic
|
|
interface=virbr0
|
|
addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts
|