1.\" $OpenBSD: resolvd.8,v 1.6 2021/05/02 15:15:44 deraadt Exp $ 2.\" 3.\" Copyright (c) 2021 Florian Obser <florian@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: May 2 2021 $ 18.Dt RESOLVD 8 19.Os 20.Sh NAME 21.Nm resolvd 22.Nd a daemon to handle nameserver configuration 23.Sh SYNOPSIS 24.Nm 25.Op Fl dv 26.Sh DESCRIPTION 27.Nm 28handles the contents of 29.Pa /etc/resolv.conf , 30which contains details of the system's DNS nameservers, and is 31read by the resolver routines in the C library. 32Nameservers are learned from various sources, incorporated in a priority 33order, then user-edited information found in the pre-existing file is 34re-appended. 35.Pp 36.Nm 37checks whether 38.Xr unwind 8 39is running, and if so places 40.Pp 41.Dl nameserver 127.0.0.1 42.Pp 43at the top, to cause local resolution. 44.Pp 45.Nm 46also monitors the routing socket for proposals learned by 47.Xr dhclient 8 , 48.Xr dhcpleased 8 , 49.Xr slaacd 8 , 50or network devices which natively learn DNS information such as 51.Xr umb 4 . 52.Pp 53These proposals are added in priority order, but commented out 54if 55.Xr unwind 8 56is running. 57.Pp 58After that, 59.Nm 60appends all user-edited lines found in the file. 61.Pp 62.Nm 63also notices if the 64.Pa /etc/resolv.conf 65file is edited, and will rewrite the file, re-blending the various 66pieces of information. 67It will also create 68.Pa /etc/resolv.conf 69if it does not exist or if it is empty. 70.Pp 71The options are as follows: 72.Bl -tag -width Ds 73.It Fl d 74Do not daemonize. 75If this option is specified, 76.Nm 77will run in the foreground and log to 78.Em stderr . 79.It Fl v 80Produce more verbose output. 81.El 82.Sh SEE ALSO 83.Xr resolv.conf 5 , 84.Xr dhclient 8 , 85.Xr dhcpleased 8 , 86.Xr slaacd 8 , 87.Xr unwind 8 88.Sh HISTORY 89The 90.Nm 91program first appeared in 92.Ox 6.9 . 93