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diff --git a/man/systemd-resolved.service.xml b/man/systemd-resolved.service.xml deleted file mode 100644 index 56f67960ce..0000000000 --- a/man/systemd-resolved.service.xml +++ /dev/null @@ -1,234 +0,0 @@ -<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<!-- - This file is part of systemd. - - Copyright 2014 Tom Gundersen - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="systemd-resolved.service" conditional='ENABLE_RESOLVED'> - - <refentryinfo> - <title>systemd-resolved.service</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Tom</firstname> - <surname>Gundersen</surname> - <email>teg@jklm.no</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>systemd-resolved.service</refentrytitle> - <manvolnum>8</manvolnum> - </refmeta> - - <refnamediv> - <refname>systemd-resolved.service</refname> - <refname>systemd-resolved</refname> - <refpurpose>Network Name Resolution manager</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <para><filename>systemd-resolved.service</filename></para> - <para><filename>/usr/lib/systemd/systemd-resolved</filename></para> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para><command>systemd-resolved</command> is a system service that provides network name resolution to local - applications. It implements a caching and validating DNS/DNSSEC stub resolver, as well as an LLMNR resolver and - responder. Local applications may submit network name resolution requests via three interfaces:</para> - - <itemizedlist> - <listitem><para>The native, fully-featured API <command>systemd-resolved</command> exposes on the bus. See the - <ulink url="http://www.freedesktop.org/wiki/Software/systemd/resolved">API Documentation</ulink> for - details. Usage of this API is generally recommended to clients as it is asynchronous and fully featured (for - example, properly returns DNSSEC validation status and interface scope for addresses as necessary for supporting - link-local networking).</para></listitem> - - <listitem><para>The glibc - <citerefentry project='man-pages'><refentrytitle>getaddrinfo</refentrytitle><manvolnum>3</manvolnum></citerefentry> API as defined - by <ulink url="https://tools.ietf.org/html/rfc3493">RFC3493</ulink> and its related resolver functions, - including <citerefentry project='man-pages'><refentrytitle>gethostbyname</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This - API is widely supported, including beyond the Linux platform. In its current form it does not expose DNSSEC - validation status information however, and is synchronous only. This API is backed by the glibc Name Service - Switch (<citerefentry project='man-pages'><refentrytitle>nss</refentrytitle><manvolnum>5</manvolnum></citerefentry>). Usage of the - glibc NSS module <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry> - is required in order to allow glibc's NSS resolver functions to resolve host names via - <command>systemd-resolved</command>.</para></listitem> - - <listitem><para>Additionally, <command>systemd-resolved</command> provides a local DNS stub listener on IP - address 127.0.0.53 on the local loopback interface. Programs issuing DNS requests directly, bypassing any local - API may be directed to this stub, in order to connect them to <command>systemd-resolved</command>. Note however - that it is strongly recommended that local programs use the glibc NSS or bus APIs instead (as described above), - as various network resolution concepts (such as link-local addressing, or LLMNR Unicode domains) cannot be mapped - to the unicast DNS protocol.</para></listitem> - </itemizedlist> - - <para>The DNS servers contacted are determined from the global settings in - <filename>/etc/systemd/resolved.conf</filename>, the per-link static settings in - <filename>/etc/systemd/network/*.network</filename> files, the per-link dynamic settings received over DHCP and any - DNS server information made available by other system services. See - <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> and - <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details - about systemd's own configuration files for DNS servers. To improve compatibility, - <filename>/etc/resolv.conf</filename> is read in order to discover configured system DNS servers, but only if it is - not a symlink to <filename>/run/systemd/resolve/resolv.conf</filename> (see below).</para> - - <para><command>systemd-resolved</command> synthesizes DNS resource records (RRs) for the following cases:</para> - - <itemizedlist> - <listitem><para>The local, configured hostname is resolved to - all locally configured IP addresses ordered by their scope, or - — if none are configured — the IPv4 address 127.0.0.2 (which - is on the local loopback) and the IPv6 address ::1 (which is the - local host).</para></listitem> - - <listitem><para>The hostnames <literal>localhost</literal> and - <literal>localhost.localdomain</literal> (as well as any hostname - ending in <literal>.localhost</literal> or <literal>.localhost.localdomain</literal>) - are resolved to the IP addresses 127.0.0.1 and ::1.</para></listitem> - - <listitem><para>The hostname <literal>gateway</literal> is - resolved to all current default routing gateway addresses, - ordered by their metric. This assigns a stable hostname to the - current gateway, useful for referencing it independently of the - current network configuration state.</para></listitem> - - <listitem><para>The mappings defined in <filename>/etc/hosts</filename> are resolved to their configured - addresses and back.</para></listitem> - </itemizedlist> - - <para>Lookup requests are routed to the available DNS servers - and LLMNR interfaces according to the following rules:</para> - - <itemizedlist> - <listitem><para>Lookups for the special hostname - <literal>localhost</literal> are never routed to the - network. (A few other, special domains are handled the same way.)</para></listitem> - - <listitem><para>Single-label names are routed to all local - interfaces capable of IP multicasting, using the LLMNR - protocol. Lookups for IPv4 addresses are only sent via LLMNR on - IPv4, and lookups for IPv6 addresses are only sent via LLMNR on - IPv6. Lookups for the locally configured host name and the - <literal>gateway</literal> host name are never routed to - LLMNR.</para></listitem> - - <listitem><para>Multi-label names are routed to all local - interfaces that have a DNS sever configured, plus the globally - configured DNS server if there is one. Address lookups from the - link-local address range are never routed to - DNS.</para></listitem> - </itemizedlist> - - <para>If lookups are routed to multiple interfaces, the first - successful response is returned (thus effectively merging the - lookup zones on all matching interfaces). If the lookup failed on - all interfaces, the last failing response is returned.</para> - - <para>Routing of lookups may be influenced by configuring - per-interface domain names. See - <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details. Lookups for a hostname ending in one of the - per-interface domains are exclusively routed to the matching - interfaces.</para> - - <para>See the <ulink url="http://www.freedesktop.org/wiki/Software/systemd/resolved"> resolved D-Bus API - Documentation</ulink> for information about the APIs <filename>systemd-resolved</filename> provides.</para> - - </refsect1> - - <refsect1> - <title><filename>/etc/resolv.conf</filename></title> - - <para>Three modes of handling <filename>/etc/resolv.conf</filename> (see - <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>) are - supported:</para> - - <itemizedlist> - <listitem><para>A static file <filename>/usr/lib/systemd/resolv.conf</filename> is provided that lists - the 127.0.0.53 DNS stub (see above) as only DNS server. This file may be symlinked from - <filename>/etc/resolv.conf</filename> in order to connect all local clients that bypass local DNS APIs to - <command>systemd-resolved</command>. This mode of operation is recommended.</para></listitem> - - <listitem><para><command>systemd-resolved</command> maintains the - <filename>/run/systemd/resolve/resolv.conf</filename> file for compatibility with traditional Linux - programs. This file may be symlinked from <filename>/etc/resolv.conf</filename> and is always kept up-to-date, - containing information about all known DNS servers. Note the file format's limitations: it does not know a - concept of per-interface DNS servers and hence only contains system-wide DNS server definitions. Note that - <filename>/run/systemd/resolve/resolv.conf</filename> should not be used directly by applications, but only - through a symlink from <filename>/etc/resolv.conf</filename>. If this mode of operation is used local clients - that bypass any local DNS API will also bypass <command>systemd-resolved</command> and will talk directly to the - known DNS servers.</para> </listitem> - - <listitem><para>Alternatively, <filename>/etc/resolv.conf</filename> may be managed by other packages, in which - case <command>systemd-resolved</command> will read it for DNS configuration data. In this mode of operation - <command>systemd-resolved</command> is consumer rather than provider of this configuration - file. </para></listitem> - </itemizedlist> - - <para>Note that the selected mode of operation for this file is detected fully automatically, depending on whether - <filename>/etc/resolv.conf</filename> is a symlink to <filename>/run/systemd/resolve/resolv.conf</filename> or - lists 127.0.0.53 as DNS server.</para> - </refsect1> - - <refsect1> - <title>Signals</title> - - <variablelist> - <varlistentry> - <term><constant>SIGUSR1</constant></term> - - <listitem><para>Upon reception of the SIGUSR1 process signal <command>systemd-resolved</command> will dump the - contents of all DNS resource record caches it maintains into the system logs.</para></listitem> - </varlistentry> - - <varlistentry> - <term><constant>SIGUSR2</constant></term> - - <listitem><para>Upon reception of the SIGUSR2 process signal <command>systemd-resolved</command> will flush all - caches it maintains. Note that it should normally not be necessary to request this explicitly – except for - debugging purposes – as <command>systemd-resolved</command> flushes the caches automatically anyway any time - the host's network configuration changes.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>See Also</title> - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>dnssec-trust-anchors.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-resolve</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>hosts</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |