+<?xml version='1.0'?> <!--*-nxml-*-->
+<!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 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_bus_negotiate_fds" conditional="ENABLE_KDBUS">
+
+ <refentryinfo>
+ <title>sd_bus_new</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_bus_negotiate_fds</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_bus_negotiate_fds</refname>
+ <refname>sd_bus_negotiate_timestamps</refname>
+ <refname>sd_bus_negotiate_creds</refname>
+
+ <refpurpose>Control feature negotiation on bus connections</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_negotiate_fds</function></funcdef>
+ <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+ <paramdef>int <parameter>b</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_negotiate_timestamp</function></funcdef>
+ <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+ <paramdef>int <parameter>b</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_negotiate_creds</function></funcdef>
+ <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+ <paramdef>int <parameter>b</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_bus_negotiate_fds()</function> controls whether
+ file descriptor passing shall be negotiated for the specified bus
+ connection. Takes a bus object and a boolean, which when true
+ enables file descriptor passing, and when false disables it. Note
+ that not all transports and servers support file descriptor
+ passing. To find out whether file descriptor passing is available
+ after negotiation use
+ <citerefentry><refentrytitle>sd_bus_can_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ and pass <constant>SD_BUS_TYPE_UNIX_FD</constant>. Note that file
+ descriptor passing is always enabled for both sending and
+ receiving or for neither, but never only in one direction. By
+ default file descriptor passing is negotiated for all
+ connections.</para>
+
+ <para>Note that when bus activation is used it is highly
+ recommended to set the <option>AcceptFileDescriptors=</option>
+ setting in the <filename>.busname</filename> unit file to the same
+ setting as negotiated by the program ultimately activated. By
+ default file descriptor passing is enabled for both.</para>
+
+ <para><function>sd_bus_negotiate_timestamps()</function> controls
+ whether implicit sender timestamps shall be attached automatically
+ to all incoming messages. Takes a bus object and a boolean, which
+ when true enables timestamping, and when false disables it. If
+ this is disabled,
+ <citerefentry><refentrytitle>sd_bus_message_get_monotonic_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_seqno</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ fail with <constant>-ENODATA</constant> on incoming messages. Note
+ that not all transports support timestamping of messages. On local
+ transports the timestamping is applied by the kernel and cannot be
+ manipulated by userspace.</para>
+
+ <para><function>sd_bus_negotiate_creds()</function> controls
+ whether implicit sender credentials shall be attached
+ automatically to all incoming messages. Takes a bus object and a
+ bit mask value, which controls which credential parameters are
+ attached. If this is not used,
+ <citerefentry><refentrytitle>sd_bus_message_get_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ fails with <constant>-ENODATA</constant> on incoming
+ messages. Note that not all transports support attaching sender
+ credentials to messages, or do not support all types of sender
+ credential parameters. On local transports the sender credentials
+ are attached by the kernel and cannot be manipulated by
+ userspace. By default no sender credentials are attached.</para>
+
+ <para>These functions may be called only before the connection has
+ been started with
+ <citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>On success, these functions returns 0 or a
+ positive integer. On failure, it returns a negative errno-style
+ error code.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Errors</title>
+
+ <para>Returned errors may indicate the following problems:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><varname>-EPERM</varname></term>
+
+ <listitem><para>The bus connection has already been started.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para><function>sd_bus_negotiate_fs()</function> and the other
+ functions described here are available as a shared library, which
+ can be compiled and linked to with the
+ <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ file.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_can_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_monotonic_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
~ianmdlvl / elogind.git / commitdiff