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diff --git a/man/sd_listen_fds.xml b/man/sd_listen_fds.xml deleted file mode 100644 index 93bf8d853f..0000000000 --- a/man/sd_listen_fds.xml +++ /dev/null @@ -1,257 +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 2010 Lennart Poettering - - 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="sd_listen_fds" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>sd_listen_fds</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd_listen_fds</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd_listen_fds</refname> - <refname>sd_listen_fds_with_names</refname> - <refname>SD_LISTEN_FDS_START</refname> - <refpurpose>Check for file descriptors passed by the system manager</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-daemon.h></funcsynopsisinfo> - - <funcsynopsisinfo>#define SD_LISTEN_FDS_START 3</funcsynopsisinfo> - - <funcprototype> - <funcdef>int <function>sd_listen_fds</function></funcdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - </funcprototype> - - <funcprototype> - <funcdef>int <function>sd_listen_fds_with_names</function></funcdef> - <paramdef>int <parameter>unset_environment</parameter></paramdef> - <paramdef>char*** <parameter>names</parameter></paramdef> - </funcprototype> - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para><function>sd_listen_fds()</function> may be invoked by a - daemon to check for file descriptors passed by the service manager as - part of the socket-based activation logic. It returns the number - of received file descriptors. If no file descriptors have been - received, zero is returned. The first file descriptor may be found - at file descriptor number 3 - (i.e. <constant>SD_LISTEN_FDS_START</constant>), the remaining - descriptors follow at 4, 5, 6, ..., if any.</para> - - <para>If a daemon receives more than one file descriptor, they - will be passed in the same order as configured in the systemd - socket unit file (see - <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details). Nonetheless, it is recommended to verify the correct - socket types before using them. To simplify this checking, the - functions - <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket_inet</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket_unix</refentrytitle><manvolnum>3</manvolnum></citerefentry> - are provided. In order to maximize flexibility, it is recommended - to make these checks as loose as possible without allowing - incorrect setups. i.e. often, the actual port number a socket is - bound to matters little for the service to work, hence it should - not be verified. On the other hand, whether a socket is a datagram - or stream socket matters a lot for the most common program logics - and should be checked.</para> - - <para>This function call will set the FD_CLOEXEC flag for all - passed file descriptors to avoid further inheritance to children - of the calling process.</para> - - <para>If multiple socket units activate the same service, the order - of the file descriptors passed to its main process is undefined. - If additional file descriptors have been passed to the service - manager using - <citerefentry><refentrytitle>sd_pid_notify_with_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s - <literal>FDSTORE=1</literal> messages, these file descriptors are - passed last, in arbitrary order, and with duplicates - removed.</para> - - <para>If the <parameter>unset_environment</parameter> parameter is - non-zero, <function>sd_listen_fds()</function> will unset the - <varname>$LISTEN_FDS</varname>, <varname>$LISTEN_PID</varname> and - <varname>$LISTEN_FDNAMES</varname> environment variables before - returning (regardless of whether the function call itself - succeeded or not). Further calls to - <function>sd_listen_fds()</function> will then return zero, but the - variables are no longer inherited by child processes.</para> - - <para><function>sd_listen_fds_with_names()</function> is like - <function>sd_listen_fds()</function>, but optionally also returns - an array of strings with identification names for the passed file - descriptors, if that is available and the - <parameter>names</parameter> parameter is non-NULL. This - information is read from the <varname>$LISTEN_FDNAMES</varname> - variable, which may contain a colon-separated list of names. For - socket-activated services, these names may be configured with the - <varname>FileDescriptorName=</varname> setting in socket unit - files, see - <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details. For file descriptors pushed into the file descriptor - store (see above), the name is set via the - <varname>FDNAME=</varname> field transmitted via - <function>sd_pid_notify_with_fds()</function>. The primary usecase - for these names are services which accept a variety of file - descriptors which are not recognizable with functions like - <function>sd_is_socket()</function> alone, and thus require - identification via a name. It is recommended to rely on named file - descriptors only if identification via - <function>sd_is_socket()</function> and related calls is not - sufficient. Note that the names used are not unique in any - way. The returned array of strings has as many entries as file - descriptors have been received, plus a final NULL pointer - terminating the array. The caller needs to free the array itself - and each of its elements with libc's <function>free()</function> - call after use. If the <parameter>names</parameter> parameter is - NULL, the call is entirely equivalent to - <function>sd_listen_fds()</function>.</para> - - <para>Under specific conditions, the following automatic file - descriptor names are returned: - - <table> - <title> - <command>Special names</command> - </title> - - <tgroup cols='2'> - <thead> - <row> - <entry>Name</entry> - <entry>Description</entry> - </row> - </thead> - <tbody> - <row> - <entry><literal>unknown</literal></entry> - <entry>The process received no name for the specific file descriptor from the service manager.</entry> - </row> - - <row> - <entry><literal>stored</literal></entry> - <entry>The file descriptor originates in the service manager's per-service file descriptor store, and the <varname>FDNAME=</varname> field was absent when the file descriptor was submitted to the service manager.</entry> - </row> - - <row> - <entry><literal>connection</literal></entry> - <entry>The service was activated in per-connection style using <varname>Accept=yes</varname> in the socket unit file, and the file descriptor is the connection socket.</entry> - </row> - </tbody> - </tgroup> - </table> - </para> - </refsect1> - - <refsect1> - <title>Return Value</title> - - <para>On failure, these calls returns a negative errno-style error - code. If - <varname>$LISTEN_FDS</varname>/<varname>$LISTEN_PID</varname> was - not set or was not correctly set for this daemon and hence no file - descriptors were received, 0 is returned. Otherwise, the number of - file descriptors passed is returned. The application may find them - starting with file descriptor SD_LISTEN_FDS_START, i.e. file - descriptor 3.</para> - </refsect1> - - <refsect1> - <title>Notes</title> - - <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/> - - <para>Internally, <function>sd_listen_fds()</function> checks - whether the <varname>$LISTEN_PID</varname> environment variable - equals the daemon PID. If not, it returns immediately. Otherwise, - it parses the number passed in the <varname>$LISTEN_FDS</varname> - environment variable, then sets the FD_CLOEXEC flag for the parsed - number of file descriptors starting from SD_LISTEN_FDS_START. - Finally, it returns the parsed - number. <function>sd_listen_fds_with_names()</function> does the - same but also parses <varname>$LISTEN_FDNAMES</varname> if - set.</para> - </refsect1> - - <refsect1> - <title>Environment</title> - - <variablelist class='environment-variables'> - <varlistentry> - <term><varname>$LISTEN_PID</varname></term> - <term><varname>$LISTEN_FDS</varname></term> - <term><varname>$LISTEN_FDNAMES</varname></term> - - <listitem><para>Set by the service manager for supervised - processes that use socket-based activation. This environment - variable specifies the data - <function>sd_listen_fds()</function> and - <function>sd_listen_fds_with_names()</function> parses. See - above for details.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>See Also</title> - - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket_inet</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_is_socket_unix</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_pid_notify_with_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |