"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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-
-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
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+ SPDX-License-Identifier: LGPL-2.1+
-->
-<refentry id="sd_bus_negotiate_fds" conditional="ENABLE_KDBUS">
+<refentry id="sd_bus_negotiate_fds" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_bus_negotiate_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>
<refnamediv>
<refname>sd_bus_negotiate_fds</refname>
- <refname>sd_bus_negotiate_timestamps</refname>
+ <refname>sd_bus_negotiate_timestamp</refname>
<refname>sd_bus_negotiate_creds</refname>
<refpurpose>Control feature negotiation on bus connections</refpurpose>
<funcdef>int <function>sd_bus_negotiate_creds</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>int <parameter>b</parameter></paramdef>
- <paramdef>uint64_t <parameter>flags</parameter></paramdef>
+ <paramdef>uint64_t <parameter>mask</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<para><function>sd_bus_negotiate_fds()</function> controls whether
file descriptor passing shall be negotiated for the specified bus
connection. It 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
+ enables file descriptor passing, and, when false, disables
+ it. Note that not all transports and servers support file
+ descriptor passing. In particular, networked transports generally
+ do not 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
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,
+ <para><function>sd_bus_negotiate_timestamp()</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. Use
<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. By default, message timestamping is
- not negotiated for all connections.</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, a
- boolean indicating wether to enable or disable the credential
- parts encoded in the bit mask value argument. Note that not all
- transports support attaching sender credentials to messages, or do
- not support all types of sender credential parameters, or might
- suppress them under certain circumstances for individual
- messages. 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>
+ <citerefentry><refentrytitle>sd_bus_message_get_seqnum</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ to query the timestamps of incoming messages. If negotiation is disabled or not supported, these
+ calls will fail with <constant>-ENODATA</constant>. Note that currently no transports support
+ timestamping of messages. By default, message timestamping is not negotiated for
+ connections.</para>
+
+ <para><function>sd_bus_negotiate_creds()</function> controls whether and which implicit sender
+ credentials shall be attached automatically to all incoming messages. Takes a bus object and a
+ boolean indicating whether to enable or disable the credential parts encoded in the bit mask
+ value argument. Note that not all transports support attaching sender credentials to messages,
+ or do not support all types of sender credential parameters, or might suppress them under
+ certain circumstances for individual messages. Specifically, dbus1 only supports
+ <constant>SD_BUS_CREDS_UNIQUE_NAME</constant>. The sender credentials are suitable for
+ authorization decisions. By default, only <constant>SD_BUS_CREDS_WELL_KNOWN_NAMES</constant> and
+ <constant>SD_BUS_CREDS_UNIQUE_NAME</constant> are enabled. In fact, these two credential fields
+ are always sent along and cannot be turned off.</para>
<para>The <function>sd_bus_negotiate_fds()</function> function may
be called only before the connection has been started with
<citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Both
<function>sd_bus_negotiate_timestamp()</function> and
- <function>sd_bus_negotiate_creds()</function> also may be called
- after a connection has been set up. Note that when operating on a
+ <function>sd_bus_negotiate_creds()</function> may also be called
+ after a connection has been set up. Note that, when operating on a
connection that is shared between multiple components of the same
program (for example via
- <citerefentry><refentrytitle>sd_bus_default</refentrytitle><manvolnum>3</manvolnum></citerefentry>)
+ <citerefentry><refentrytitle>sd_bus_default</refentrytitle><manvolnum>3</manvolnum></citerefentry>),
it is highly recommended to only enable additional per message
metadata fields, but never disable them again, in order not to
disable functionality needed by other components.</para>
<refsect1>
<title>Return Value</title>
- <para>On success, these functions returns 0 or a
+ <para>On success, these functions return 0 or a
positive integer. On failure, they return a negative errno-style
error code.</para>
</refsect1>
</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 project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- file.</para>
- </refsect1>
+ <xi:include href="libelogind-pkgconfig.xml" />
<refsect1>
<title>See Also</title>
<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>,
- <citerefentry><refentrytitle>systemd.busname</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>sd_bus_message_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_seqnum</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_message_get_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff