resolvconf.conf.5.in

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.Dd April 23, 2025
.Dt RESOLVCONF.CONF 5
.Os
.Sh NAME
.Nm resolvconf.conf
.Nd resolvconf configuration file
.Sh DESCRIPTION
.Nm
is the configuration file for
.Xr resolvconf 8 .
The
.Nm
file is a shell script that is sourced by
.Xr resolvconf 8 ,
meaning that
.Nm
must contain valid shell commands.
Listed below are the standard
.Nm
variables that may be set.
If the values contain whitespace, wildcards or other special shell characters,
ensure they are quoted and escaped correctly.
See the
.Sy replace
variable for an example on quoting.
.Pp
After updating this file, you may wish to run
.Nm resolvconf -u
to apply the new configuration.
.Pp
When a dynamically generated list is appended or prepended to, the whole
is made unique where left-most wins.
.Sh RESOLVCONF OPTIONS
.Bl -tag -width indent
.It Sy resolvconf
Set to NO to disable
.Nm resolvconf
from running any subscribers.
Defaults to YES.
.It Sy allow_interfaces
If set, only these interfaces will be processed.
.It Sy deny_interfaces
If set, these interfaces will not be processed.
.It Sy exclude
Is a space separated list of key/value pairs to match.
If all key/value pairs in one element can be found in the file,
then the whole file will be excluded from processing.
The syntax is this:
.Va $keyword Ns / Ns Va $match Ns Op / Ns Va $keyword Ns / Ns Va $match
.Pp
For example given this configuration:
.Bd -compact -literal -offset indent
exclude="search/foo*/nameserver/1.2.3.4 search/bar.org"
.Ed
Then any resolv.conf with both a search option starting with foo with a nameserver of 1.2.3.4
OR a search option of bar.org would be excluded.
.It Sy interface_order
These interfaces will always be processed first.
If unset, defaults to the following:-
.Bd -compact -literal -offset indent
lo lo[0-9]*
.Ed
.It Sy dynamic_order
These interfaces will be processed next, unless they have a metric.
If unset, defaults to the following:-
.Bd -compact -literal -offset indent
tap[0-9]* tun[0-9]* vpn vpn[0-9]* wg[0-9]* ppp[0-9]* ippp[0-9]*
.Ed
.It Sy inclusive_interfaces
Ignore any exclusive marking for these interfaces.
This is handy when 3rd party integrations force the
.Nm resolvconf -x
option and you want to disable it easily.
.It Sy local_nameservers
If unset, defaults to the following:-
.Bd -compact -literal -offset indent
127.* 0.0.0.0 255.255.255.255 ::1
.Ed
.It Sy search_domains
Prepend search domains to the dynamically generated list.
.It Sy search_domains_append
Append search domains to the dynamically generated list.
.It Sy domain_blacklist
A list of domains to be removed from consideration.
To remove a domain, you can use foo.*
To remove a sub domain, you can use *.bar
.It Sy name_servers
Prepend name servers to the dynamically generated list.
You should set this to 127.0.0.1 if you use a local name server other than
libc.
.It Sy name_servers_append
Append name servers to the dynamically generated list.
.It Sy name_server_blacklist
A list of name servers to be removed from consideration.
The default is 0.0.0.0 as some faulty routers send it via DHCP.
To remove a block, you can use 192.168.*
.It Sy private_interfaces
These interfaces name servers will only be queried for the domains listed
in their resolv.conf.
Useful for VPN domains.
Setting
.Sy private_interfaces Ns ="*"
will stop the forwarding of the root zone and allows the local resolver to
recursively query the root servers directly.
Requires a local nameserver other than libc.
This is equivalent to the
.Nm resolvconf -p
option.
.It Sy public_interfaces
Force these interface to be public, overriding the private marking.
This is handy when 3rd party integrations force the
.Nm resolvconf -p
option and you want to disable it easily.
.It Sy replace
Is a space separated list of replacement keywords.
The syntax is this:
.Va $keyword Ns / Ns Va $match Ns / Ns Va $replacement
.Pp
Example, given this resolv.conf:
.Bd -compact -literal -offset indent
domain foo.org
search foo.org dead.beef
nameserver 1.2.3.4
nameserver 2.3.4.5
.Ed
and this configuration:
.Bd -compact -literal -offset indent
replace="search/foo*/bar.com"
replace="$replace nameserver/1.2.3.4/5.6.7.8"
replace="$replace nameserver/2.3.4.5/"
.Ed
you would get this resolv.conf instead:
.Bd -compact -literal -offset indent
domain foo.org
search bar.com
nameserver 5.6.7.8
.Ed
.It Sy replace_sub
Works the same way as
.Sy replace
except it works on each space separated value rather than the whole line,
so it's useful for the replacing a single domain within the search directive.
Using the same example resolv.conf and changing
.Sy replace
to
.Sy replace_sub ,
you would get this resolv.conf instead:
.Bd -compact -literal -offset indent
domain foo.org
search bar.com dead.beef
nameserver 5.6.7.8
.Ed
.It Sy state_dir
Override the default state directory of
.Pa @VARDIR@ .
This should not be changed once
.Nm resolvconf
is in use unless the old directory is copied to the new one.
.El
.Sh LIBC OPTIONS
The following variables affect
.Xr resolv.conf 5
directly:-
.Bl -tag -width indent
.It Sy resolv_conf
Defaults to
.Pa /etc/resolv.conf
if not set.
Set to
.Pa /dev/null
to stop
.Xr resolvconf 8
from changing it.
.It Sy resolv_conf_options
A list of libc resolver options, as specified in
.Xr resolv.conf 5 .
.It Sy resolv_conf_passthrough
When set to YES the latest resolv.conf is written to
.Sy resolv_conf
without any alteration.
When set to /dev/null or NULL,
.Sy resolv_conf_local_only
is defaulted to NO,
.Sy local_nameservers
is unset unless overridden and only the information set in
.Nm
is written to
.Sy resolv_conf .
.It Sy resolv_conf_sortlist
A libc resolver sortlist, as specified in
.Xr resolv.conf 5 .
.It Sy resolv_conf_local_only
If a local name server is configured then the default is just to specify that
and ignore all other entries as they will be configured for the local
name server.
Set this to NO to also list non-local nameservers.
This will give you working DNS even if the local nameserver stops functioning
at the expense of duplicated server queries.
.It Sy append_nameservers
Append name servers to the dynamically generated list.
.It Sy prepend_nameservers
Prepend name servers to the dynamically generated list.
.It Sy append_search
Append search domains to the dynamically generated list.
.It Sy prepend_search
Prepend search domains to the dynamically generated list.
.It Sy resolv_conf_mv
Defaults to NO.
Defines if
.Pa /etc/resolv.conf
is updated by writing to a temporary file and then moving it
vs writing directly to it.
.El
.Sh SUBSCRIBER OPTIONS
openresolv ships with subscribers for the name servers
.Xr dnsmasq 8 ,
.Xr named 8 ,
.Xr pdnsd 8 ,
.Xr pdns_recursor 1 ,
and
.Xr unbound 8 .
Each subscriber can create configuration files which should be included in
the subscribers main configuration file.
.Pp
To disable a subscriber, simply set its name to NO.
If the subscriber name has a dash in it, then replace it with an underscore.
For example, to disable the libc subscriber you would set:
.Bd -compact -literal -offset indent
libc=NO
.Ed
.Bl -tag -width indent
.It Sy dnsmasq_conf
This file tells dnsmasq which name servers to use for specific domains.
.It Sy dnsmasq_resolv
This file tells dnsmasq which name servers to use for global lookups.
.Pp
Example resolvconf.conf for dnsmasq:
.Bd -compact -literal -offset indent
name_servers=127.0.0.1
dnsmasq_conf=/etc/dnsmasq-conf.conf
dnsmasq_resolv=/etc/dnsmasq-resolv.conf
.Ed
.Pp
Example dnsmasq.conf:
.Bd -compact -literal -offset indent
listen-address=127.0.0.1
# If dnsmasq is compiled for DBus then we can take
# advantage of not having to restart dnsmasq.
enable-dbus
conf-file=/etc/dnsmasq-conf.conf
resolv-file=/etc/dnsmasq-resolv.conf
.Ed
.It Sy named_options
Include this file in the named options block.
This file tells named which name servers to use for global lookups.
.It Sy named_zones
Include this file in the named global scope, after the options block.
This file tells named which name servers to use for specific domains.
.Pp
Example resolvconf.conf for named:
.Bd -compact -literal -offset indent
name_servers=127.0.0.1
named_options=/etc/named-options.conf
named_zones=/etc/named-zones.conf
.Ed
.Pp
Example named.conf:
.Bd -compact -literal -offset indent
options {
	listen-on { 127.0.0.1; };
	include "/etc/named-options.conf";
};

include "/etc/named-zones.conf";
.Ed
.It Sy pdnsd_conf
This is the main pdnsd configuration file which we modify to add our
forward domains to.
If this variable is not set then we rely on the pdnsd configuration file
setup to read
.Pa pdnsd_resolv
as documented below.
.It Sy pdnsd_resolv
This file tells pdnsd about global name servers.
If this variable is not set then it's written to
.Pa pdnsd_conf .
.Pp
Example resolvconf.conf for pdnsd:
.Bd -compact -literal -offset indent
name_servers=127.0.0.1
pdnsd_conf=/etc/pdnsd.conf
# pdnsd_resolv=/etc/pdnsd-resolv.conf
.Ed
.Pp
Example pdnsd.conf:
.Bd -compact -literal -offset indent
global {
	server_ip = 127.0.0.1;
	status_ctl = on;
}
server {
	# A server definition is required, even if empty.
	label="empty";
	proxy_only=on;
	# file="/etc/pdnsd-resolv.conf";
}
.Ed
.It Sy pdns_zones
This file tells pdns_recursor about specific and global name servers.
.Pp
Example resolvconf.conf for pdns_recursor:
.Bd -compact -literal -offset indent
name_servers=127.0.0.1
pdns_zones=/etc/pdns/recursor-zones.conf
.Ed
.Pp
Example recursor.conf:
.Bd -compact -literal -offset indent
allow-from=127.0.0.0/8, ::1/128
forward-zones-file=/etc/pdns/recursor-zones.conf
.Ed
.It Sy systemd_resolved_conf
This file tells systemd-resolved about global name servers.
.Pp
Example resolvconf.conf for systemd-resolved:
.Bd -compact -literal -offset indent
name_servers=127.0.0.53
resolv_conf_options="edns0 trust-ad"
systemd_resolved_conf=/run/systemd/resolved.conf.d/60-resolvconf.conf
.Ed
.It Sy unbound_conf
This file tells unbound about specific and global name servers.
.It Sy unbound_insecure
When set to YES, unbound marks the domains as insecure, thus ignoring DNSSEC.
.It Sy unbound_private
When set to YES, unbound marks the domains as private, allowing it and its subdomains to contain private addresses.
.It Sy unbound_forward_zone_options
Options appended to each forward zone.
Each option should be separated by an embedded new line.
.Pp
Example resolvconf.conf for unbound:
.Bd -compact -literal -offset indent
name_servers=127.0.0.1
unbound_conf=/etc/unbound-resolvconf.conf
.Ed
.Pp
Example unbound.conf:
.Bd -compact -literal -offset indent
include: /etc/unbound-resolvconf.conf
.Ed
.El
.Sh SUBSCRIBER INTEGRATION
Not all distributions store the files the subscribers need in the same
locations.
For example, named service scripts have been called named, bind and rc.bind
and they could be located in a directory called /etc/rc.d, /etc/init.d or
similar.
Each subscriber attempts to automatically configure itself, but not every
distribution has been catered for.
Also, users could equally want to use a different version from the one
installed by default, such as bind8 and bind9.
To accommodate this, the subscribers have these files in configurable
variables, documented below.
.Bl -tag -width indent
.It Sy dnsmasq_service
Name of the dnsmasq service.
.It Sy dnsmasq_restart
Command to restart the dnsmasq service.
.It Sy dnsmasq_pid
Location of the dnsmasq pidfile.
.It Sy libc_service
Name of the libc service.
.It Sy libc_restart
Command to restart the libc service.
.It Sy named_service
Name of the named service.
.It Sy named_restart
Command to restart the named service.
.It Sy pdnsd_restart
Command to restart the pdnsd service.
.It Sy pdns_service
Command to restart the pdns_recursor service.
.It Sy pdns_restart
Command to restart the pdns_recursor service.
.It Sy unbound_service
Name of the unbound service.
.It Sy unbound_restart
Command to restart the unbound service.
.It Sy unbound_pid
Location of the unbound pidfile.
.El
.Sh SEE ALSO
.Xr sh 1 ,
.Xr resolv.conf 5 ,
.Xr resolvconf 8
.Sh AUTHORS
.An Roy Marples Aq Mt roy@marples.name
.Sh BUGS
Each distribution is a special snowflake and likes to name the same thing
differently, namely the named service script.
.Pp
Please report them to
.Lk https://roy.marples.name/projects/openresolv