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authorRalf Habacker <ralf.habacker@freenet.de>2013-02-05 02:19:28 +0100
committerSimon McVittie <simon.mcvittie@collabora.co.uk>2013-02-14 13:27:27 +0000
commit60cf73ce6482ae89fdf1777f3c7f8f767b36a278 (patch)
tree59aa33a7544498c758440ea344f91197e2b6b957 /doc/dbus-daemon.1.xml.in
parent6676a7db9cb30dad9bdd477e5949ca12a3c15cf6 (diff)
downloaddbus-60cf73ce6482ae89fdf1777f3c7f8f767b36a278.tar.gz
Updated man docbook xml sources from man page source using doclifter.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=59805 Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Diffstat (limited to 'doc/dbus-daemon.1.xml.in')
-rw-r--r--doc/dbus-daemon.1.xml.in582
1 files changed, 359 insertions, 223 deletions
diff --git a/doc/dbus-daemon.1.xml.in b/doc/dbus-daemon.1.xml.in
index f331699c..bc602bbf 100644
--- a/doc/dbus-daemon.1.xml.in
+++ b/doc/dbus-daemon.1.xml.in
@@ -1,17 +1,17 @@
<?xml version="1.0" encoding="ISO-8859-1"?>
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
- "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
+ "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<!-- lifted from troff+man by doclifter -->
-<refentry id='dbus-daemon'>
-<!-- -->
-<!-- dbus\-daemon manual page. -->
-<!-- Copyright (C) 2003 Red Hat, Inc. -->
+<refentry id='dbusdaemon1in'>
+
+<!-- dbus&bsol;-daemon manual page.
+ Copyright (C) 2003,2008 Red Hat, Inc. -->
<refmeta>
<refentrytitle>dbus-daemon</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
-<refnamediv id='name'>
+<refnamediv>
<refname>dbus-daemon</refname>
<refpurpose>Message bus daemon</refpurpose>
</refnamediv>
@@ -41,35 +41,29 @@ application that uses this library to implement a message bus
daemon. Multiple programs connect to the message bus daemon and can
exchange messages with one another.</para>
-
-<para>There are two standard message bus instances: the systemwide message bus
-(installed on many systems as the "messagebus" init service) and the
+<para>There are two standard message bus instances: the systemwide message bus
+(installed on many systems as the "messagebus" init service) and the
per-user-login-session message bus (started each time a user logs in).
-<command>dbus-daemon</command> is used for both of these instances, but with
+<command>dbus-daemon</command> is used for both of these instances, but with
a different configuration file.</para>
-
<para>The --session option is equivalent to
-"--config-file=/etc/dbus-1/session.conf" and the --system
+"--config-file=@EXPANDED_SYSCONFDIR@/dbus-1/session.conf" and the --system
option is equivalent to
-"--config-file=/etc/dbus-1/system.conf". By creating
+"--config-file=@EXPANDED_SYSCONFDIR@/dbus-1/system.conf". By creating
additional configuration files and using the --config-file option,
additional special-purpose message bus daemons could be created.</para>
+<para>The systemwide daemon is normally launched by an init script,
+standardly called simply "messagebus".</para>
-<para>The systemwide daemon is normally launched by an init script,
-standardly called simply "messagebus".</para>
-
-
-<para>The systemwide daemon is largely used for broadcasting system events,
+<para>The systemwide daemon is largely used for broadcasting system events,
such as changes to the printer queue, or adding/removing devices.</para>
-
-<para>The per-session daemon is used for various interprocess communication
-among desktop applications (however, it is not tied to X or the GUI
+<para>The per-session daemon is used for various interprocess communication
+among desktop applications (however, it is not tied to X or the GUI
in any way).</para>
-
<para>SIGHUP will cause the D-Bus daemon to PARTIALLY reload its
configuration file and to flush its user/group information caches. Some
configuration changes would require kicking all apps off the bus; so they will
@@ -90,25 +84,28 @@ with SIGHUP.</para>
<varlistentry>
<term><option>--fork</option></term>
<listitem>
-<para>Force the message bus to fork and become a daemon, even if
+<para>Force the message bus to fork and become a daemon, even if
the configuration file does not specify that it should.
In most contexts the configuration file already gets this
-right, though.</para>
+right, though.
+<option>--nofork</option>
+Force the message bus not to fork and become a daemon, even if
+the configuration file specifies that it should.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>--print-address[=DESCRIPTOR]</option></term>
<listitem>
-<para>Print the address of the message bus to standard output, or
-to the given file descriptor. This is used by programs that
+<para>Print the address of the message bus to standard output, or
+to the given file descriptor. This is used by programs that
launch the message bus.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>--print-pid[=DESCRIPTOR]</option></term>
<listitem>
-<para>Print the process ID of the message bus to standard output, or
-to the given file descriptor. This is used by programs that
+<para>Print the process ID of the message bus to standard output, or
+to the given file descriptor. This is used by programs that
launch the message bus.</para>
</listitem>
</varlistentry>
@@ -129,6 +126,33 @@ bus.</para>
<term><option>--version</option></term>
<listitem>
<para>Print the version of the daemon.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>--introspect</option></term>
+ <listitem>
+<para>Print the introspection information for all D-Bus internal interfaces.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>--address[=ADDRESS]</option></term>
+ <listitem>
+<para>Set the address to listen on. This option overrides the address
+configured in the configuration file.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>--systemd-activation</option></term>
+ <listitem>
+<para>Enable systemd-style service activation. Only useful in conjunction
+with the systemd system and session manager on Linux.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>--nopidfile</option></term>
+ <listitem>
+<para>Don't write a PID file even if one is configured in the configuration
+files.</para>
</listitem>
</varlistentry>
@@ -137,23 +161,20 @@ bus.</para>
<refsect1 id='configuration_file'><title>CONFIGURATION FILE</title>
<para>A message bus daemon has a configuration file that specializes it
-for a particular application. For example, one configuration
-file might set up the message bus to be a systemwide message bus,
+for a particular application. For example, one configuration
+file might set up the message bus to be a systemwide message bus,
while another might set it up to be a per-user-login-session bus.</para>
-
<para>The configuration file also establishes resource limits, security
parameters, and so forth.</para>
-
<para>The configuration file is not part of any interoperability
specification and its backward compatibility is not guaranteed; this
document is documentation, not specification.</para>
-
<para>The standard systemwide and per-session message bus setups are
-configured in the files "/etc/dbus-1/system.conf" and
-"/etc/dbus-1/session.conf". These files normally
+configured in the files "@EXPANDED_SYSCONFDIR@/dbus-1/system.conf" and
+"@EXPANDED_SYSCONFDIR@/dbus-1/session.conf". These files normally
&lt;include&gt; a system-local.conf or session-local.conf; you can put local
overrides in those files to avoid modifying the primary configuration
files.</para>
@@ -171,43 +192,50 @@ doctype declaration:</para>
<para>The following elements may be present in the configuration file.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;busconfig&gt;</emphasis></term>
- <listitem>
-<para></para>
- </listitem>
- </varlistentry>
-</variablelist>
+<itemizedlist remap='TP'>
+
+ <listitem><para><emphasis remap='I'>&lt;busconfig&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>Root element.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;type&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;type&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>The well-known type of the message bus. Currently known values are
"system" and "session"; if other values are set, they should be
either added to the D-Bus specification, or namespaced. The last
-&lt;type&gt; element "wins" (previous values are ignored).</para>
+&lt;type&gt; element "wins" (previous values are ignored). This element
+only controls which message bus specific environment variables are
+set in activated clients. Most of the policy that distinguishes a
+session bus from the system bus is controlled from the other elements
+in the configuration file.</para>
+
+
+<para>If the well-known type of the message bus is "session", then the
+DBUS_STARTER_BUS_TYPE environment variable will be set to "session"
+and the DBUS_SESSION_BUS_ADDRESS environment variable will be set
+to the address of the session bus. Likewise, if the type of the
+message bus is "system", then the DBUS_STARTER_BUS_TYPE environment
+variable will be set to "system" and the DBUS_SESSION_BUS_ADDRESS
+environment variable will be set to the address of the system bus
+(which is normally well known anyway).</para>
<para>Example: &lt;type&gt;session&lt;/type&gt;</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;include&gt;</emphasis></term>
- <listitem>
-<para></para>
- </listitem>
- </varlistentry>
-</variablelist>
+<itemizedlist remap='TP'>
+
+ <listitem><para><emphasis remap='I'>&lt;include&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>Include a file &lt;include&gt;filename.conf&lt;/include&gt; at this point. If the
filename is relative, it is located relative to the configuration file
@@ -215,19 +243,16 @@ doing the including.</para>
<para>&lt;include&gt; has an optional attribute "ignore_missing=(yes|no)"
-which defaults to "no" if not provided. This attribute
-controls whether it's a fatal error for the included file
+which defaults to "no" if not provided. This attribute
+controls whether it's a fatal error for the included file
to be absent.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;includedir&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;includedir&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>Include all files in &lt;includedir&gt;foo.d&lt;/includedir&gt; at this
point. Files in the directory are included in undefined order.
@@ -237,18 +262,15 @@ Only files ending in ".conf" are included.</para>
<para>This is intended to allow extension of the system bus by particular
packages. For example, if CUPS wants to be able to send out
notification of printer queue changes, it could install a file to
-/etc/dbus-1/system.d that allowed all apps to receive
+@EXPANDED_SYSCONFDIR@/dbus-1/system.d that allowed all apps to receive
this message and allowed the printer daemon user to send it.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;user&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;user&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>The user account the daemon should run as, as either a username or a
UID. If the daemon cannot change to this UID on startup, it will exit.
@@ -261,97 +283,127 @@ about its UID.</para>
<para>The user is changed after the bus has completed initialization. So
sockets etc. will be created before changing user, but no data will be
-read from clients before changing user. This means that sockets
-and PID files can be created in a location that requires root
+read from clients before changing user. This means that sockets
+and PID files can be created in a location that requires root
privileges for writing.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;fork&gt;</emphasis></term>
- <listitem>
-<para></para>
- </listitem>
- </varlistentry>
-</variablelist>
+<itemizedlist remap='TP'>
-<para>If present, the bus daemon becomes a real daemon (forks
-into the background, etc.). This is generally used
+ <listitem><para><emphasis remap='I'>&lt;fork&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
+
+<para>If present, the bus daemon becomes a real daemon (forks
+into the background, etc.). This is generally used
rather than the --fork command line option.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;listen&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;keep_umask&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
+
+<para>If present, the bus daemon keeps its original umask when forking.
+This may be useful to avoid affecting the behavior of child processes.</para>
+
+<itemizedlist remap='TP'>
-<para>Add an address that the bus should listen on. The
-address is in the standard D-Bus format that contains
+ <listitem><para><emphasis remap='I'>&lt;listen&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
+
+<para>Add an address that the bus should listen on. The
+address is in the standard D-Bus format that contains
a transport name plus possible parameters/options.</para>
<para>Example: &lt;listen&gt;unix:path=/tmp/foo&lt;/listen&gt;</para>
-<para>If there are multiple &lt;listen&gt; elements, then the bus listens
-on multiple addresses. The bus will pass its address to
-started services or other interested parties with
-the last address given in &lt;listen&gt; first. That is,
+<para>Example: &lt;listen&gt;tcp:host=localhost,port=1234&lt;/listen&gt;</para>
+
+
+<para>If there are multiple &lt;listen&gt; elements, then the bus listens
+on multiple addresses. The bus will pass its address to
+started services or other interested parties with
+the last address given in &lt;listen&gt; first. That is,
apps will try to connect to the last &lt;listen&gt; address first.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;auth&gt;</emphasis></term>
- <listitem>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+<para>tcp sockets can accept IPv4 addresses, IPv6 addresses or hostnames.
+If a hostname resolves to multiple addresses, the server will bind
+to all of them. The family=ipv4 or family=ipv6 options can be used
+to force it to bind to a subset of addresses</para>
+
+
+<para>Example: &lt;listen&gt;tcp:host=localhost,port=0,family=ipv4&lt;/listen&gt;</para>
+
+
+<para>A special case is using a port number of zero (or omitting the port),
+which means to choose an available port selected by the operating
+system. The port number chosen can be obtained with the
+--print-address command line parameter and will be present in other
+cases where the server reports its own address, such as when
+DBUS_SESSION_BUS_ADDRESS is set.</para>
+
+
+<para>Example: &lt;listen&gt;tcp:host=localhost,port=0&lt;/listen&gt;</para>
+
+
+<para>tcp addresses also allow a bind=hostname option, which will override
+the host option specifying what address to bind to, without changing
+the address reported by the bus. The bind option can also take a
+special name '*' to cause the bus to listen on all local address
+(INADDR_ANY). The specified host should be a valid name of the local
+machine or weird stuff will happen.</para>
+
+
+<para>Example: &lt;listen&gt;tcp:host=localhost,bind=*,port=0&lt;/listen&gt;</para>
+
+<itemizedlist remap='TP'>
+
+ <listitem><para><emphasis remap='I'>&lt;auth&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>Lists permitted authorization mechanisms. If this element doesn't
exist, then all known mechanisms are allowed. If there are multiple
&lt;auth&gt; elements, all the listed mechanisms are allowed. The order in
which mechanisms are listed is not meaningful.</para>
-
+
<para>Example: &lt;auth&gt;EXTERNAL&lt;/auth&gt;</para>
<para>Example: &lt;auth&gt;DBUS_COOKIE_SHA1&lt;/auth&gt;</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;servicedir&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;servicedir&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>Adds a directory to scan for .service files. Directories are
-scanned starting with the last to appear in the config file
-(the first .service file found that provides a particular
+scanned starting with the last to appear in the config file
+(the first .service file found that provides a particular
service will be used).</para>
<para>Service files tell the bus how to automatically start a program.
-They are primarily used with the per-user-session bus,
+They are primarily used with the per-user-session bus,
not the systemwide bus.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;standard_session_servicedirs/&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;standard_session_servicedirs/&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>&lt;standard_session_servicedirs/&gt; is equivalent to specifying a series
of &lt;servicedir/&gt; elements for each of the data directories in the "XDG
@@ -367,18 +419,48 @@ otherwise try your favorite search engine.</para>
<para>The &lt;standard_session_servicedirs/&gt; option is only relevant to the
per-user-session bus daemon defined in
-/etc/dbus-1/session.conf. Putting it in any other
+@EXPANDED_SYSCONFDIR@/dbus-1/session.conf. Putting it in any other
configuration file would probably be nonsense.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;limit&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;standard_system_servicedirs/&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
+
+<para>&lt;standard_system_servicedirs/&gt; specifies the standard system-wide
+activation directories that should be searched for service files.
+This option defaults to @EXPANDED_DATADIR@/dbus-1/system-services.</para>
+
+
+<para>The &lt;standard_system_servicedirs/&gt; option is only relevant to the
+per-system bus daemon defined in
+@EXPANDED_SYSCONFDIR@/dbus-1/system.conf. Putting it in any other
+configuration file would probably be nonsense.</para>
+
+<itemizedlist remap='TP'>
+
+ <listitem><para><emphasis remap='I'>&lt;servicehelper/&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
+
+<para>&lt;servicehelper/&gt; specifies the setuid helper that is used to launch
+system daemons with an alternate user. Typically this should be
+the dbus-daemon-launch-helper executable in located in libexec.</para>
+
+
+<para>The &lt;servicehelper/&gt; option is only relevant to the per-system bus daemon
+defined in @EXPANDED_SYSCONFDIR@/dbus-1/system.conf. Putting it in any other
+configuration file would probably be nonsense.</para>
+
+<itemizedlist remap='TP'>
+
+ <listitem><para><emphasis remap='I'>&lt;limit&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>&lt;limit&gt; establishes a resource limit. For example:</para>
<literallayout remap='.nf'>
@@ -392,31 +474,36 @@ Available limit names are:</para>
<literallayout remap='.nf'>
"max_incoming_bytes" : total size in bytes of messages
incoming from a single connection
+ "max_incoming_unix_fds" : total number of unix fds of messages
+ incoming from a single connection
"max_outgoing_bytes" : total size in bytes of messages
queued up for a single connection
+ "max_outgoing_unix_fds" : total number of unix fds of messages
+ queued up for a single connection
"max_message_size" : max size of a single message in
bytes
- "service_start_timeout" : milliseconds (thousandths) until
+ "max_message_unix_fds" : max unix fds of a single message
+ "service_start_timeout" : milliseconds (thousandths) until
a started service has to connect
"auth_timeout" : milliseconds (thousandths) a
connection is given to
authenticate
- "max_completed_connections" : max number of authenticated connections
+ "max_completed_connections" : max number of authenticated connections
"max_incomplete_connections" : max number of unauthenticated
connections
"max_connections_per_user" : max number of completed connections from
the same user
"max_pending_service_starts" : max number of service launches in
progress at the same time
- "max_names_per_connection" : max number of names a single
+ "max_names_per_connection" : max number of names a single
connection can own
- "max_match_rules_per_connection": max number of match rules for a single
+ "max_match_rules_per_connection": max number of match rules for a single
connection
- "max_replies_per_connection" : max number of pending method
+ "max_replies_per_connection" : max number of pending method
replies per connection
(number of calls-in-progress)
- "reply_timeout" : milliseconds (thousandths)
- until a method call times out
+ "reply_timeout" : milliseconds (thousandths)
+ until a method call times out
</literallayout> <!-- .fi -->
@@ -430,49 +517,60 @@ number of users that can work together to denial-of-service all other users by u
up all connections on the systemwide bus.</para>
-<para>Limits are normally only of interest on the systemwide bus, not the user session
+<para>Limits are normally only of interest on the systemwide bus, not the user session
buses.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;policy&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;policy&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>The &lt;policy&gt; element defines a security policy to be applied to a particular
set of connections to the bus. A policy is made up of
&lt;allow&gt; and &lt;deny&gt; elements. Policies are normally used with the systemwide bus;
-they are analogous to a firewall in that they allow expected traffic
+they are analogous to a firewall in that they allow expected traffic
and prevent unexpected traffic.</para>
-<para>The &lt;policy&gt; element has one of three attributes:</para>
+<para>Currently, the system bus has a default-deny policy for sending method calls
+and owning bus names. Everything else, in particular reply messages, receive
+checks, and signals has a default allow policy.</para>
+
+
+<para>In general, it is best to keep system services as small, targeted programs which
+run in their own process and provide a single bus name. Then, all that is needed
+is an &lt;allow&gt; rule for the "own" permission to let the process claim the bus
+name, and a "send_destination" rule to allow traffic from some or all uids to
+your service.</para>
+
+
+<para>The &lt;policy&gt; element has one of four attributes:</para>
<literallayout remap='.nf'>
context="(default|mandatory)"
+ at_console="(true|false)"
user="username or userid"
group="group name or gid"
</literallayout> <!-- .fi -->
-<para>
-Policies are applied to a connection as follows:</para>
+<para>Policies are applied to a connection as follows:</para>
<literallayout remap='.nf'>
- all context="default" policies are applied
- all group="connection's user's group" policies are applied
in undefined order
- all user="connection's auth user" policies are applied
in undefined order
+ - all at_console="true" policies are applied
+ - all at_console="false" policies are applied
- all context="mandatory" policies are applied
</literallayout> <!-- .fi -->
-<para>Policies applied later will override those applied earlier,
-when the policies overlap. Multiple policies with the same
-user/group/context are applied in the order they appear
+<para>Policies applied later will override those applied earlier,
+when the policies overlap. Multiple policies with the same
+user/group/context are applied in the order they appear
in the config file.</para>
<variablelist remap='TP'>
@@ -493,16 +591,16 @@ statements, and works just like &lt;deny&gt; but with the inverse meaning.</para
<para>The possible attributes of these elements are:</para>
<literallayout remap='.nf'>
send_interface="interface_name"
- send_member="method_or_signal_name"
- send_error="error_name"
- send_destination="name"
- send_type="method_call" | "method_return" | "signal" | "error"
+ send_member="method_or_signal_name"
+ send_error="error_name"
+ send_destination="name"
+ send_type="method_call" | "method_return" | "signal" | "error"
send_path="/path/name"
receive_interface="interface_name"
- receive_member="method_or_signal_name"
- receive_error="error_name"
- receive_sender="name"
+ receive_member="method_or_signal_name"
+ receive_error="error_name"
+ receive_sender="name"
receive_type="method_call" | "method_return" | "signal" | "error"
receive_path="/path/name"
@@ -520,9 +618,7 @@ statements, and works just like &lt;deny&gt; but with the inverse meaning.</para
<para>Examples:</para>
<literallayout remap='.nf'>
- &lt;deny send_interface="org.freedesktop.System" send_member="Reboot"/&gt;
- &lt;deny receive_interface="org.freedesktop.System" receive_member="Reboot"/&gt;
- &lt;deny own="org.freedesktop.System"/&gt;
+ &lt;deny send_destination="org.freedesktop.Service" send_interface="org.freedesktop.System" send_member="Reboot"/&gt;
&lt;deny send_destination="org.freedesktop.System"/&gt;
&lt;deny receive_sender="org.freedesktop.System"/&gt;
&lt;deny user="john"/&gt;
@@ -534,34 +630,29 @@ statements, and works just like &lt;deny&gt; but with the inverse meaning.</para
particular action. If it matches, the action is denied (unless later
rules in the config file allow it).</para>
-
<para>send_destination and receive_sender rules mean that messages may not be
sent to or received from the *owner* of the given name, not that
they may not be sent *to that name*. That is, if a connection
owns services A, B, C, and sending to A is denied, sending to B or C
will not work either.</para>
-
<para>The other send_* and receive_* attributes are purely textual/by-value
matches against the given field in the message header.</para>
-
<para>"Eavesdropping" occurs when an application receives a message that
-was explicitly addressed to a name the application does not own.
-Eavesdropping thus only applies to messages that are addressed to
-services (i.e. it does not apply to signals).</para>
+was explicitly addressed to a name the application does not own, or
+is a reply to such a message. Eavesdropping thus only applies to
+messages that are addressed to services and replies to such messages
+(i.e. it does not apply to signals).</para>
-
-<para>For &lt;allow&gt;, eavesdrop="true" indicates that the rule matches even
-when eavesdropping. eavesdrop="false" is the default and means that
+<para>For &lt;allow&gt;, eavesdrop="true" indicates that the rule matches even
+when eavesdropping. eavesdrop="false" is the default and means that
the rule only allows messages to go to their specified recipient.
-For &lt;deny&gt;, eavesdrop="true" indicates that the rule matches
+For &lt;deny&gt;, eavesdrop="true" indicates that the rule matches
only when eavesdropping. eavesdrop="false" is the default for &lt;deny&gt;
-also, but here it means that the rule applies always, even when
+also, but here it means that the rule applies always, even when
not eavesdropping. The eavesdrop attribute can only be combined with
-receive rules (with receive_* attributes).</para>
-
-
+send and receive rules (with send_* and receive_* attributes).</para>
<para>The [send|receive]_requested_reply attribute works similarly to the eavesdrop
attribute. It controls whether the &lt;deny&gt; or &lt;allow&gt; matches a reply
@@ -582,7 +673,7 @@ requested. [send|receive]_requested_reply="true" indicates that the rule applies
always, regardless of pending reply state.</para>
-<para>user and group denials mean that the given user or group may
+<para>user and group denials mean that the given user or group may
not connect to the message bus.</para>
@@ -591,6 +682,7 @@ the character "*" can be substituted, meaning "any." Complex globs
like "foo.bar.*" aren't allowed for now because they'd be work to
implement and maybe encourage sloppy security anyway.</para>
+
<para>&lt;allow own_prefix="a.b"/&gt; allows you to own the name "a.b" or any
name whose first dot-separated elements are "a.b": in particular,
you can own "a.b.c" or "a.b.c.d", but not "a.bc" or "a.c".
@@ -599,6 +691,7 @@ define a meaning for subtrees of well-known names, such as
org.freedesktop.Telepathy.ConnectionManager.(anything)
and org.freedesktop.ReserveDevice1.(anything).</para>
+
<para>It does not make sense to deny a user or group inside a &lt;policy&gt;
for a user or group; user/group denials can only be inside
context="default" or context="mandatory" policies.</para>
@@ -617,42 +710,40 @@ rule, since "whether the message can be sent" and "whether it can be
received" are evaluated separately.</para>
-<para>Be careful with send_interface/receive_interface, because the
-interface field in messages is optional.</para>
+<para>Be careful with send_interface/receive_interface, because the
+interface field in messages is optional. In particular, do NOT
+specify &lt;deny send_interface="org.foo.Bar"/&gt;! This will cause
+no-interface messages to be blocked for all services, which is
+almost certainly not what you intended. Always use rules of
+the form: &lt;deny send_interface="org.foo.Bar" send_destination="org.foo.Service"/&gt;</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;selinux&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;selinux&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>The &lt;selinux&gt; element contains settings related to Security Enhanced Linux.
More details below.</para>
-<variablelist remap='TP'>
- <varlistentry>
- <term><emphasis remap='I'>&lt;associate&gt;</emphasis></term>
- <listitem>
+<itemizedlist remap='TP'>
-<para></para> <!-- FIXME: blank list item -->
- </listitem>
- </varlistentry>
-</variablelist>
+ <listitem><para><emphasis remap='I'>&lt;associate&gt;</emphasis></para></listitem>
+
+
+</itemizedlist>
<para>An &lt;associate&gt; element appears below an &lt;selinux&gt; element and
creates a mapping. Right now only one kind of association is possible:</para>
<literallayout remap='.nf'>
- &lt;associate own="org.freedesktop.Foobar" context="foo_t"/&gt;
+ &lt;associate own="org.freedesktop.Foobar" context="foo_t"/&gt;
</literallayout> <!-- .fi -->
<para>This means that if a connection asks to own the name
"org.freedesktop.Foobar" then the source context will be the context
-of the connection and the target context will be "foo_t" - see the
+of the connection and the target context will be "foo_t" - see the
short discussion of SELinux below.</para>
@@ -663,7 +754,7 @@ NOT the context of the connection owning the name.</para>
<para>There's currently no way to set a default for owning any name, if
we add this syntax it will look like:</para>
<literallayout remap='.nf'>
- &lt;associate own="*" context="foo_t"/&gt;
+ &lt;associate own="*" context="foo_t"/&gt;
</literallayout> <!-- .fi -->
<para>If you find a reason this is useful, let the developers know.
Right now the default will be the security context of the bus itself.</para>
@@ -715,30 +806,75 @@ the first connection as source, security context of the second connection
as target, object class "dbus" and requested permission "send_msg".</para>
-<para>If a security context is not available for a connection
-(impossible when using UNIX domain sockets), then the target
+<para>If a security context is not available for a connection
+(impossible when using UNIX domain sockets), then the target
context used is the context of the bus daemon itself.
-There is currently no way to change this default, because we're
-assuming that only UNIX domain sockets will be used to
-connect to the systemwide bus. If this changes, we'll
+There is currently no way to change this default, because we're
+assuming that only UNIX domain sockets will be used to
+connect to the systemwide bus. If this changes, we'll
probably add a way to set the default connection context.</para>
-<para>Second, any time a connection asks to own a name,
-the bus daemon will check permissions with the security
+<para>Second, any time a connection asks to own a name,
+the bus daemon will check permissions with the security
context of the connection as source, the security context specified
-for the name in the config file as target, object
+for the name in the config file as target, object
class "dbus" and requested permission "acquire_svc".</para>
-<para>The security context for a bus name is specified with the
+<para>The security context for a bus name is specified with the
&lt;associate&gt; element described earlier in this document.
-If a name has no security context associated in the
-configuration file, the security context of the bus daemon
+If a name has no security context associated in the
+configuration file, the security context of the bus daemon
itself will be used.</para>
</refsect1>
+<refsect1 id='debugging'><title>DEBUGGING</title>
+<para>If you're trying to figure out where your messages are going or why
+you aren't getting messages, there are several things you can try.</para>
+
+<para>Remember that the system bus is heavily locked down and if you
+haven't installed a security policy file to allow your message
+through, it won't work. For the session bus, this is not a concern.</para>
+
+<para>The simplest way to figure out what's happening on the bus is to run
+the <emphasis remap='I'>dbus-monitor</emphasis> program, which comes with the D-Bus
+package. You can also send test messages with <emphasis remap='I'>dbus-send</emphasis>. These
+programs have their own man pages.</para>
+
+<para>If you want to know what the daemon itself is doing, you might consider
+running a separate copy of the daemon to test against. This will allow you
+to put the daemon under a debugger, or run it with verbose output, without
+messing up your real session and system daemons.</para>
+
+<para>To run a separate test copy of the daemon, for example you might open a terminal
+and type:</para>
+<literallayout remap='.nf'>
+ DBUS_VERBOSE=1 dbus-daemon --session --print-address
+</literallayout> <!-- .fi -->
+
+<para>The test daemon address will be printed when the daemon starts. You will need
+to copy-and-paste this address and use it as the value of the
+DBUS_SESSION_BUS_ADDRESS environment variable when you launch the applications
+you want to test. This will cause those applications to connect to your
+test bus instead of the DBUS_SESSION_BUS_ADDRESS of your real session bus.</para>
+
+<para>DBUS_VERBOSE=1 will have NO EFFECT unless your copy of D-Bus
+was compiled with verbose mode enabled. This is not recommended in
+production builds due to performance impact. You may need to rebuild
+D-Bus if your copy was not built with debugging in mind. (DBUS_VERBOSE
+also affects the D-Bus library and thus applications using D-Bus; it may
+be useful to see verbose output on both the client side and from the daemon.)</para>
+
+<para>If you want to get fancy, you can create a custom bus
+configuration for your test bus (see the session.conf and system.conf
+files that define the two default configurations for example). This
+would allow you to specify a different directory for .service files,
+for example.</para>
+
+</refsect1>
+
<refsect1 id='author'><title>AUTHOR</title>
<para>See <ulink url='http://www.freedesktop.org/software/dbus/doc/AUTHORS'>http://www.freedesktop.org/software/dbus/doc/AUTHORS</ulink></para>