.\" $OpenBSD: unwind.conf.5,v 1.17 2019/11/06 14:19:59 florian Exp $ .\" .\" Copyright (c) 2018 Florian Obser .\" Copyright (c) 2005 Esben Norby .\" Copyright (c) 2004 Claudio Jeker .\" Copyright (c) 2003, 2004 Henning Brauer .\" Copyright (c) 2002 Daniel Hartmeier .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: November 6 2019 $ .Dt UNWIND.CONF 5 .Os .Sh NAME .Nm unwind.conf .Nd validating DNS resolver configuration file .Sh DESCRIPTION The .Xr unwind 8 daemon is a validating DNS resolver. .Pp The .Nm config file is divided into the following main sections: .Bl -tag -width xxxx .It Sy Macros User-defined variables may be defined and used later, simplifying the configuration file. .It Sy Global Configuration Global settings for .Xr unwind 8 . .El .Pp Additional configuration files can be included with the .Ic include keyword. .Sh MACROS Macros can be defined that will later be expanded in context. Macro names must start with a letter, digit, or underscore, and may contain any of those characters. Macro names may not be reserved words (for example, .Ic forwarder , .Ic port , or .Ic DoT ) . Macros are not expanded inside quotes. .Pp For example: .Bd -literal -offset indent fwd1=192.0.2.53 fwd2=192.0.2.153 forwarder { $fwd1 $fwd2 } .Ed .Sh GLOBAL CONFIGURATION .Bl -tag -width Ds .It Ic block list Ar file Op Cm log A file containing domains to block, one per line. If a domain from this list is queried .Nm unwind answers with a return code of .Cm refused . With .Cm log blocked queries are logged. .It Ic captive portal Brq ... .Nm unwind can detect when it is running behind a .Dq captive portal by sending an HTTP request and checking the response against the configured expected response. The check is triggered when .Xr dhclient 8 reports new nameservers. If the response does not match, .Nm unwind uses the DHCP provided nameservers and periodically re-checks if the user passed the captive portal. .Bl -tag -width Ds .It Ic auto Op Cm yes | no When .Ic auto is set to .Cm yes .Nm unwind automatically triggers a captive portal check when the network is changed. When set to .Cm no a captive portal check can be triggered by .Xr unwindctl 8 . The default is .Cm yes . .It Ic expected response Ar response The body of the HTTP response is compared to .Ar response . The default is the empty string. .It Ic expected status Ar status The expected HTTP status code. The default is 200. .It Ic url Ar URL URL to send HTTP queries to. This parameter is required. .El .It Ic forwarder Brq Ar address Oo Ic port Ar number Oc Oo Oo Ic authentication name Ar name Oc Ic DoT Oc ... A list of addresses of DNS name servers to forward queries to. .Ic port defaults to 53. If .Ic DoT is specified, use DNS over TLS when sending queries to the server at .Ar address . The default .Ic port is 853. .Ar name validates the certificate of the DNS over TLS server. .It Ic preference Brq Ar type ... A list of DNS name server types to specify the preference in which name servers are picked. Validating name servers are always picked over non-validating name servers. DNS name server types are: .Pp .Bl -tag -width "forwarder" -compact .It Ic stub Name servers learned via DHCP, queried using the libc functions. See .Xr asr_run 3 . Will never validate. Useful when running behind broken middle boxes that do not like edns0. .It Ic dhcp Name servers learned via DHCP. .It Ic DoT DNS over TLS name servers configured in .Nm . .It Ic forwarder Name servers configured in .Nm . .It Ic recursor .Nm unwind itself recursively resolves names. .El .Pp The default preference is .Ic DoT forwarder recursor dhcp stub . .El .Sh FILES .Bl -tag -width "/etc/examples/unwind.conf" -compact .It Pa /etc/examples/unwind.conf Example configuration file. .It Pa /etc/unwind.conf The default .Xr unwind 8 configuration file. .El .Sh SEE ALSO .Xr rc.conf.local 8 , .Xr unwind 8 , .Xr unwindctl 8 .Sh HISTORY The .Nm file format first appeared in .Ox 6.5 .