Remove the old, vague Naming Conventions section
[platform/upstream/dbus.git] / doc / dbus-specification.xml
index ac98d1c..86e2b9b 100644 (file)
@@ -1,14 +1,13 @@
-<?xml version="1.0" standalone="no"?>
+<?xml version="1.0" standalone="no" ?>
 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"
 [
 ]>
-
 <article id="index">
   <articleinfo>
     <title>D-Bus Specification</title>
-    <releaseinfo>Version 0.12</releaseinfo>
-    <date>7 November 2006</date>
+    <releaseinfo>Version 0.17</releaseinfo>
+    <date>(not final)</date>
     <authorgroup>
       <author>
        <firstname>Havoc</firstname>
           </address>
        </affiliation>
       </author>
+      <author>
+       <firstname>Sven</firstname>
+       <surname>Herzberg</surname>
+       <affiliation>
+         <orgname>Imendio AB</orgname>
+         <address>
+            <email>sven@imendio.com</email>
+          </address>
+       </affiliation>
+      </author>
     </authorgroup>
+   <revhistory>
+     <revision>
+       <revnumber>current</revnumber>
+       <date><ulink url='http://cgit.freedesktop.org/dbus/dbus/log/doc/dbus-specification.xml'>commit log</ulink></date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.16</revnumber>
+       <date>11 April 2011</date>
+       <authorinitials></authorinitials>
+       <revremark>add path_namespace, arg0namespace; argNpath matches object
+        paths</revremark>
+     </revision>
+     <revision>
+       <revnumber>0.15</revnumber>
+       <date>3 November 2010</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.14</revnumber>
+       <date>12 May 2010</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.13</revnumber>
+       <date>23 Dezember 2009</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.12</revnumber>
+       <date>7 November, 2006</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.11</revnumber>
+       <date>6 February 2005</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.10</revnumber>
+       <date>28 January 2005</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.9</revnumber>
+       <date>7 Januar 2005</date>
+       <authorinitials></authorinitials>
+       <revremark></revremark>
+     </revision>
+     <revision>
+       <revnumber>0.8</revnumber>
+       <date>06 September 2003</date>
+       <authorinitials></authorinitials>
+       <revremark>First released document.</revremark>
+     </revision>
+   </revhistory>
   </articleinfo>
 
   <sect1 id="introduction">
               </row><row>
                 <entry><literal>STRUCT</literal></entry>
                 <entry>114 (ASCII 'r'), 40 (ASCII '('), 41 (ASCII ')')</entry>
-                <entry>Struct</entry>
+                <entry>Struct; type code 114 'r' is reserved for use in
+                  bindings and implementations to represent the general
+                  concept of a struct, and must not appear in signatures
+                  used on D-Bus.</entry>
               </row><row>
                 <entry><literal>VARIANT</literal></entry>
                 <entry>118 (ASCII 'v') </entry>
               </row><row>
                 <entry><literal>DICT_ENTRY</literal></entry>
                 <entry>101 (ASCII 'e'), 123 (ASCII '{'), 125 (ASCII '}') </entry>
-                <entry>Entry in a dict or map (array of key-value pairs)</entry>
+                <entry>Entry in a dict or map (array of key-value pairs).
+                  Type code 101 'e' is reserved for use in bindings and
+                  implementations to represent the general concept of a
+                  dict or dict-entry, and must not appear in signatures
+                  used on D-Bus.</entry>
+              </row><row>
+                <entry><literal>UNIX_FD</literal></entry>
+                <entry>104 (ASCII 'h')</entry>
+                <entry>Unix file descriptor</entry>
+              </row>
+              <row>
+                <entry>(reserved)</entry>
+                <entry>109 (ASCII 'm')</entry>
+                <entry>Reserved for <ulink
+                    url="https://bugs.freedesktop.org/show_bug.cgi?id=27857">a
+                  'maybe' type compatible with the one in GVariant</ulink>,
+                  and must not appear in signatures used on D-Bus until
+                  specified here</entry>
+              </row>
+              <row>
+                <entry>(reserved)</entry>
+                <entry>42 (ASCII '*')</entry>
+                <entry>Reserved for use in bindings/implementations to
+                  represent any <firstterm>single complete type</firstterm>,
+                  and must not appear in signatures used on D-Bus.</entry>
+              </row>
+              <row>
+                <entry>(reserved)</entry>
+                <entry>63 (ASCII '?')</entry>
+                <entry>Reserved for use in bindings/implementations to
+                  represent any <firstterm>basic type</firstterm>, and must
+                  not appear in signatures used on D-Bus.</entry>
+              </row>
+              <row>
+                <entry>(reserved)</entry>
+                <entry>64 (ASCII '@'), 38 (ASCII '&amp;'),
+                  94 (ASCII '^')</entry>
+                <entry>Reserved for internal use by bindings/implementations,
+                  and must not appear in signatures used on D-Bus.
+                  GVariant uses these type-codes to encode calling
+                  conventions.</entry>
               </row>
             </tbody>
           </tgroup>
              </row><row>
                 <entry><literal>VARIANT</literal></entry>
                 <entry>
-                  A variant type has a marshaled <literal>SIGNATURE</literal>
-                  followed by a marshaled value with the type
-                  given in the signature.
-                  Unlike a message signature, the variant signature 
-                  can contain only a single complete type.
-                  So "i" is OK, "ii" is not.
+                  A variant type has a marshaled
+                  <literal>SIGNATURE</literal> followed by a marshaled
+                  value with the type given in the signature.  Unlike
+                  a message signature, the variant signature can
+                  contain only a single complete type.  So "i", "ai"
+                  or "(ii)" is OK, but "ii" is not.  Use of variants may not
+                  cause a total message depth to be larger than 64, including
+                 other container types such as structures.
                 </entry>
                 <entry>
                   1 (alignment of the signature)
                 <entry>
                   8
                 </entry>
+              </row><row>
+                <entry><literal>UNIX_FD</literal></entry>
+                <entry>32-bit unsigned integer in the message's byte
+                order. The actual file descriptors need to be
+                transferred out-of-band via some platform specific
+                mechanism. On the wire, values of this type store the index to the
+                file descriptor in the array of file descriptors that
+                accompany the message.</entry>
+                <entry>4</entry>
              </row>
             </tbody>
           </tgroup>
           </itemizedlist>
         </para>
 
+        <para>
+          Object paths are often namespaced by starting with a reversed
+          domain name and containing an interface version number, in the
+          same way as
+          <link linkend="message-protocol-names-interface">interface
+            names</link> and
+          <link linkend="message-protocol-names-bus">well-known
+            bus names</link>.
+          This makes it possible to implement more than one service, or
+          more than one version of a service, in the same process,
+          even if the services share a connection but cannot otherwise
+          co-operate (for instance, if they are implemented by different
+          plugins).
+        </para>
+
+        <para>
+          For instance, if the owner of <literal>example.com</literal> is
+          developing a D-Bus API for a music player, they might use the
+          hierarchy of object paths that start with
+          <literal>/com/example/MusicPlayer1</literal> for its objects.
+        </para>
       </sect3>
 
-      
       <sect3 id="message-protocol-marshaling-signature">
         <title>Valid Signatures</title>
         <para>
                 <entry>2nd <literal>UINT32</literal></entry>
                 <entry>The serial of this message, used as a cookie 
                   by the sender to identify the reply corresponding
-                  to this request.
+                  to this request. This must not be zero.
                 </entry>
               </row>      
               <row>
                   If omitted, it is assumed to be the 
                   empty signature "" (i.e. the body must be 0-length).</entry>
                 </row>
+                <row>
+                  <entry><literal>UNIX_FDS</literal></entry>
+                  <entry>9</entry>
+                  <entry><literal>UINT32</literal></entry>
+                  <entry>optional</entry>
+                  <entry>The number of Unix file descriptors that
+                  accompany the message.  If omitted, it is assumed
+                  that no Unix file descriptors accompany the
+                  message. The actual file descriptors need to be
+                  transferred via platform specific mechanism
+                  out-of-band. They must be sent at the same time as
+                  part of the message itself. They may not be sent
+                  before the first byte of the message itself is
+                  transferred or after the last byte of the message
+                  itself.</entry>
+                </row>
               </tbody>
             </tgroup>
           </informaltable>
            <listitem><para>Interface names must not exceed the maximum name length.</para></listitem>
           </itemizedlist>
         </para>
+
+        <para>
+          Interface names should start with the reversed DNS domain name of
+          the author of the interface (in lower-case), like interface names
+          in Java. It is conventional for the rest of the interface name
+          to consist of words run together, with initial capital letters
+          on all words ("CamelCase"). Several levels of hierarchy can be used.
+          It is also a good idea to include the major version of the interface
+          in the name, and increment it if incompatible changes are made;
+          this way, a single object can implement several versions of an
+          interface in parallel, if necessary.
+        </para>
+
+        <para>
+          For instance, if the owner of <literal>example.com</literal> is
+          developing a D-Bus API for a music player, they might define
+          interfaces called <literal>com.example.MusicPlayer1</literal>,
+          <literal>com.example.MusicPlayer1.Track</literal> and
+          <literal>com.example.MusicPlayer1.Seekable</literal>.
+        </para>
+
+        <para>
+          D-Bus does not distinguish between the concepts that would be
+          called classes and interfaces in Java: either can be identified on
+          D-Bus by an interface name.
+        </para>
       </sect3>
       <sect3 id="message-protocol-names-bus">
         <title>Bus names</title>
         <para>
           Connections have one or more bus names associated with them.
-          A connection has exactly one bus name that is a unique connection
-          name. The unique connection name remains with the connection for
-          its entire lifetime.
+          A connection has exactly one bus name that is a <firstterm>unique
+            connection name</firstterm>. The unique connection name remains
+          with the connection for its entire lifetime.
           A bus name is of type <literal>STRING</literal>,
           meaning that it must be valid UTF-8. However, there are also
           some additional restrictions that apply to bus names 
           specifically:
           <itemizedlist>
             <listitem><para>Bus names that start with a colon (':')
-                character are unique connection names.
+                character are unique connection names. Other bus names
+                are called <firstterm>well-known bus names</firstterm>.
                 </para>
             </listitem>
             <listitem><para>Bus names are composed of 1 or more elements separated by
           Note that the hyphen ('-') character is allowed in bus names but
           not in interface names.
         </para>
+
+        <para>
+          Like <link linkend="message-protocol-names-interface">interface
+            names</link>, well-known bus names should start with the
+          reversed DNS domain name of the author of the interface (in
+          lower-case), and it is conventional for the rest of the well-known
+          bus name to consist of words run together, with initial
+          capital letters. As with interface names, including a version
+          number in well-known bus names is a good idea; it's possible to
+          have the well-known bus name for more than one version
+          simultaneously if backwards compatibility is required.
+        </para>
+
+        <para>
+          If a well-known bus name implies the presence of a "main" interface,
+          that "main" interface is often given the same name as
+          the well-known bus name, and situated at the corresponding object
+          path. For instance, if the owner of <literal>example.com</literal>
+          is developing a D-Bus API for a music player, they might define
+          that any application that takes the well-known name
+          <literal>com.example.MusicPlayer1</literal> should have an object
+          at the object path <literal>/com/example/MusicPlayer1</literal>
+          which implements the interface
+          <literal>com.example.MusicPlayer1</literal>.
+        </para>
       </sect3>
       <sect3 id="message-protocol-names-member">
         <title>Member names</title>
            <listitem><para>Must be at least 1 byte in length.</para></listitem>
           </itemizedlist>
         </para>
+
+        <para>
+          It is conventional for member names on D-Bus to consist of
+          capitalized words with no punctuation ("camel-case").
+          Method names should usually be verbs, such as
+          <literal>GetItems</literal>, and signal names should usually be
+          a description of an event, such as <literal>ItemsChanged</literal>.
+        </para>
       </sect3>
       <sect3 id="message-protocol-names-error">
         <title>Error names</title>
         <para>
           Error names have the same restrictions as interface names.
         </para>
+
+        <para>
+          Error names have the same naming conventions as interface
+          names, and often contain <literal>.Error.</literal>; for instance,
+          the owner of <literal>example.com</literal> might define the
+          errors <literal>com.example.MusicPlayer.Error.FileNotFound</literal>
+          and <literal>com.example.MusicPlayer.Error.OutOfMemory</literal>.
+          The errors defined by D-Bus itself, such as
+          <literal>org.freedesktop.DBus.Error.Failed</literal>, follow a
+          similar pattern.
+        </para>
       </sect3>
     </sect2>
 
          <listitem><para>BEGIN</para></listitem>
          <listitem><para>DATA &lt;data in hex encoding&gt;</para></listitem>
          <listitem><para>ERROR [human-readable error explanation]</para></listitem>
+         <listitem><para>NEGOTIATE_UNIX_FD</para></listitem>
        </itemizedlist>
 
         From server to client are as follows:
          <listitem><para>OK &lt;GUID in hex&gt;</para></listitem>
          <listitem><para>DATA &lt;data in hex encoding&gt;</para></listitem>
          <listitem><para>ERROR</para></listitem>
+         <listitem><para>AGREE_UNIX_FD</para></listitem>
        </itemizedlist>
       </para>
       <para>
         an OK command must be sent to the client.
       </para>
       <para>
-        The first octet received by the client after the \r\n of the OK
-        command must be the first octet of the authenticated/encrypted 
-        stream of D-Bus messages.
-      </para>
-      <para>
         The first octet received by the server after the \r\n of the BEGIN
         command from the client must be the first octet of the
         authenticated/encrypted stream of D-Bus messages.
       </para>
+      <para>
+        If BEGIN is received by the server, the first octet received
+        by the client after the \r\n of the OK command must be the
+        first octet of the authenticated/encrypted stream of D-Bus
+        messages.
+      </para>
     </sect2>
     <sect2 id="auth-command-cancel">
       <title>CANCEL Command</title>
     <sect2 id="auth-command-ok">
       <title>OK Command</title>
       <para>
-        The OK command indicates that the client has been authenticated,
-        and that further communication will be a stream of D-Bus messages
-        (optionally encrypted, as negotiated) rather than this protocol.
+        The OK command indicates that the client has been
+        authenticated. The client may now proceed with negotiating
+        Unix file descriptor passing. To do that it shall send
+        NEGOTIATE_UNIX_FD to the server.
       </para>
       <para>
-        The first octet received by the client after the \r\n of the OK
-        command must be the first octet of the authenticated/encrypted 
-        stream of D-Bus messages.
+        Otherwise, the client must respond to the OK command by
+        sending a BEGIN command, followed by its stream of messages,
+        or by disconnecting.  The server must not accept additional
+        commands using this protocol after the BEGIN command has been
+        received. Further communication will be a stream of D-Bus
+        messages (optionally encrypted, as negotiated) rather than
+        this protocol.
       </para>
       <para>
-        The client must respond to the OK command by sending a BEGIN
-        command, followed by its stream of messages, or by disconnecting.
-        The server must not accept additional commands using this protocol 
-        after the OK command has been sent.
+        If a client sends BEGIN the first octet received by the client
+        after the \r\n of the OK command must be the first octet of
+        the authenticated/encrypted stream of D-Bus messages.
       </para>
       <para>
         The OK command has one argument, which is the GUID of the server.
         negotiate extensions or changes to the D-Bus protocol in the future.
       </para>
     </sect2>
+    <sect2 id="auth-command-negotiate-unix-fd">
+      <title>NEGOTIATE_UNIX_FD Command</title>
+      <para>
+        The NEGOTIATE_UNIX_FD command indicates that the client
+        supports Unix file descriptor passing. This command may only
+        be sent after the connection is authenticated, i.e. after OK
+        was received by the client. This command may only be sent on
+        transports that support Unix file descriptor passing.
+      </para>
+      <para>
+        On receiving NEGOTIATE_UNIX_FD the server must respond with
+        either AGREE_UNIX_FD or ERROR. It shall respond the former if
+        the transport chosen supports Unix file descriptor passing and
+        the server supports this feature. It shall respond the latter
+        if the transport does not support Unix file descriptor
+        passing, the server does not support this feature, or the
+        server decides not to enable file descriptor passing due to
+        security or other reasons.
+      </para>
+    </sect2>
+    <sect2 id="auth-command-agree-unix-fd">
+      <title>AGREE_UNIX_FD Command</title>
+      <para>
+        The AGREE_UNIX_FD command indicates that the server supports
+        Unix file descriptor passing. This command may only be sent
+        after the connection is authenticated, and the client sent
+        NEGOTIATE_UNIX_FD to enable Unix file descriptor passing. This
+        command may only be sent on transports that support Unix file
+        descriptor passing.
+      </para>
+      <para>
+        On receiving AGREE_UNIX_FD the client must respond with BEGIN,
+        followed by its stream of messages, or by disconnecting.  The
+        server must not accept additional commands using this protocol
+        after the BEGIN command has been received. Further
+        communication will be a stream of D-Bus messages (optionally
+        encrypted, as negotiated) rather than this protocol.
+      </para>
+    </sect2>
+    <sect2 id="auth-command-future">
+      <title>Future Extensions</title>
+      <para>
+        Future extensions to the authentication and negotiation
+        protocol are possible. For that new commands may be
+        introduced. If a client or server receives an unknown command
+        it shall respond with ERROR and not consider this fatal. New
+        commands may be introduced both before, and after
+        authentication, i.e. both before and after the OK command.
+      </para>
+    </sect2>
     <sect2 id="auth-examples">
       <title>Authentication examples</title>
       
             C: BEGIN
           </programlisting>
        </figure>
+        <figure>
+         <title>Example of successful magic cookie authentication with successful negotiation of Unix FD passing</title>
+         <programlisting>
+            (MAGIC_COOKIE is a made up mechanism)
+
+            C: AUTH MAGIC_COOKIE 3138363935333137393635383634
+            S: OK 1234deadbeef
+            C: NEGOTIATE_UNIX_FD
+            S: AGREE_UNIX_FD
+            C: BEGIN
+          </programlisting>
+       </figure>
+        <figure>
+         <title>Example of successful magic cookie authentication with unsuccessful negotiation of Unix FD passing</title>
+         <programlisting>
+            (MAGIC_COOKIE is a made up mechanism)
+
+            C: AUTH MAGIC_COOKIE 3138363935333137393635383634
+            S: OK 1234deadbeef
+            C: NEGOTIATE_UNIX_FD
+            S: ERROR
+            C: BEGIN
+          </programlisting>
+       </figure>
       </para>
     </sect2>
     <sect2 id="auth-states">
           directory.
         </para>
         <para>
+          Throughout this description, "hex encoding" must output the digits
+          from a to f in lower-case; the digits A to F must not be used
+          in the DBUS_COOKIE_SHA1 mechanism.
+        </para>
+        <para>
           Authentication proceeds as follows:
           <itemizedlist>
             <listitem>
               <para>
                 The client sends the username it would like to authenticate 
-                as.
+                as, hex-encoded.
               </para>
             </listitem>
             <listitem>
                 The server sends the name of its "cookie context" (see below); a
                 space character; the integer ID of the secret cookie the client
                 must demonstrate knowledge of; a space character; then a
-                hex-encoded randomly-generated challenge string.
+                randomly-generated challenge string, all of this hex-encoded into
+                one, single string.
               </para>
             </listitem>
             <listitem>
               <para>
-                The client locates the cookie, and generates its own hex-encoded
-                randomly-generated challenge string.  The client then
-                concatenates the server's hex-encoded challenge, a ":"
-                character, its own hex-encoded challenge, another ":" character,
-                and the hex-encoded cookie.  It computes the SHA-1 hash of this
-                composite string.  It sends back to the server the client's
-                hex-encoded challenge string, a space character, and the SHA-1
-                hash.
+                The client locates the cookie and generates its own
+                randomly-generated challenge string. The client then concatenates
+                the server's decoded challenge, a ":" character, its own challenge,
+                another ":" character, and the cookie. It computes the SHA-1 hash
+                of this composite string as a hex digest. It concatenates the
+                client's challenge string, a space character, and the SHA-1 hex
+                digest, hex-encodes the result and sends it back to the server.
               </para>
             </listitem>
             <listitem>
       [FIXME we need to specify in detail each transport and its possible arguments]
     
       Current transports include: unix domain sockets (including 
-      abstract namespace on linux), TCP/IP, and a debug/testing transport using 
-      in-process pipes. Future possible transports include one that 
+      abstract namespace on linux), launchd, TCP/IP, and a debug/testing transport
+      using in-process pipes. Future possible transports include one that
       tunnels over X11 protocol.
     </para>
   
        length path name.  Names which were shorter than the fixed length
        would be padded by Nul bytes.
       </para>
+      <para>
+        Unix domain sockets are not available on windows. 
+      </para>
+      <sect3 id="transports-unix-domain-sockets-addresses">
+        <title>Server Address Format</title>
+        <para> 
+          Unix domain socket addresses are identified by the "unix:" prefix 
+          and support the following key/value pairs:
+        </para>
+        <informaltable>
+         <tgroup cols="3">
+          <thead>
+           <row>
+            <entry>Name</entry>
+            <entry>Values</entry>
+            <entry>Description</entry>
+           </row>
+          </thead>
+          <tbody>
+           <row>
+            <entry>path</entry>
+            <entry>(path)</entry>
+            <entry>path of the unix domain socket. If set, the "tmpdir" and "abstract" key must not be set.</entry>
+          </row>
+          <row>
+            <entry>tmpdir</entry>
+            <entry>(path)</entry>
+            <entry>temporary directory in which a socket file with a random file name starting with 'dbus-' will be created by the server. This key can only be used in server addresses, not in client addresses. If set, the "path" and "abstract" key must not be set.</entry>
+          </row>
+          <row>
+            <entry>abstract</entry>
+            <entry>(string)</entry>
+            <entry>unique string (path) in the abstract namespace. If set, the "path" or "tempdir" key must not be set.</entry>
+          </row>
+        </tbody>
+        </tgroup>
+       </informaltable>
+      </sect3>
     </sect2>
-  </sect1>
+    <sect2 id="transports-launchd">
+      <title>launchd</title>
+      <para>
+        launchd is a open-source server management system that replaces init, inetd
+        and cron on Apple Mac OS X versions 10.4 and above. It provides a common session
+        bus address for each user and deprecates the X11-enabled D-Bus launcher on OSX.
+      </para>
 
-  <sect1 id="naming-conventions">
-    <title>Naming Conventions</title>
-    
-    <para>
-      D-Bus namespaces are all lowercase and correspond to reversed domain
-      names, as with Java. e.g. "org.freedesktop"
-    </para>
-    <para>
-      Interface, signal, method, and property names are "WindowsStyleCaps", note
-      that the first letter is capitalized, unlike Java.
-    </para>
+      <para>
+        launchd allocates a socket and provides it with the unix path through the
+        DBUS_LAUNCHD_SESSION_BUS_SOCKET variable in launchd's environment. Every process
+        spawned by launchd (or dbus-daemon, if it was started by launchd) can access
+        it through its environment.
+        Other processes can query for the launchd socket by executing:
+        $ launchctl getenv DBUS_LAUNCHD_SESSION_BUS_SOCKET
+        This is normally done by the D-Bus client library so doesn't have to be done
+        manually.
+      </para>
+      <para>
+        launchd is not available on Microsoft Windows.
+      </para>
+      <sect3 id="transports-launchd-addresses">
+        <title>Server Address Format</title>
+        <para>
+          launchd addresses are identified by the "launchd:" prefix
+          and support the following key/value pairs:
+        </para>
+        <informaltable>
+         <tgroup cols="3">
+          <thead>
+           <row>
+            <entry>Name</entry>
+            <entry>Values</entry>
+            <entry>Description</entry>
+           </row>
+          </thead>
+          <tbody>
+           <row>
+            <entry>env</entry>
+            <entry>(environment variable)</entry>
+            <entry>path of the unix domain socket for the launchd created dbus-daemon.</entry>
+          </row>
+        </tbody>
+        </tgroup>
+       </informaltable>
+      </sect3>
+    </sect2>
+    <sect2 id="transports-tcp-sockets">
+      <title>TCP Sockets</title>
+      <para>
+        The tcp transport provides TCP/IP based connections between clients
+        located on the same or different hosts. 
+      </para>
+      <para>
+        Using tcp transport without any additional secure authentification mechanismus 
+        over a network is unsecure. 
+      </para>
+      <para>  
+        Windows notes: Because of the tcp stack on windows does not provide sending 
+        credentials over a tcp connection, the EXTERNAL authentification 
+        mechanismus does not work. 
+      </para>
+      <sect3 id="transports-tcp-sockets-addresses">
+        <title>Server Address Format</title>
+        <para> 
+         TCP/IP socket addresses are identified by the "tcp:" prefix 
+         and support the following key/value pairs:
+        </para>
+        <informaltable>
+         <tgroup cols="3">
+          <thead>
+           <row>
+            <entry>Name</entry>
+            <entry>Values</entry>
+            <entry>Description</entry>
+           </row>
+          </thead>
+          <tbody>
+           <row>
+            <entry>host</entry>
+            <entry>(string)</entry>
+            <entry>dns name or ip address</entry>
+          </row>
+          <row>
+           <entry>port</entry>
+           <entry>(number)</entry>
+           <entry>The tcp port the server will open. A zero value let the server 
+            choose a free port provided from the underlaying operating system. 
+            libdbus is able to retrieve the real used port from the server.  
+           </entry>
+          </row>
+          <row>
+           <entry>family</entry>
+           <entry>(string)</entry>
+           <entry>If set, provide the type of socket family either "ipv4" or "ipv6". If unset, the family is unspecified.</entry>
+          </row>
+         </tbody>
+        </tgroup>
+       </informaltable>
+      </sect3>
+    </sect2>
+    <sect2 id="transports-nonce-tcp-sockets">
+      <title>Nonce-secured TCP Sockets</title>
+      <para>
+        The nonce-tcp transport provides a secured TCP transport, using a
+        simple authentication mechanism to ensure that only clients with read
+        access to a certain location in the filesystem can connect to the server.
+        The server writes a secret, the nonce, to a file and an incoming client
+        connection is only accepted if the client sends the nonce right after
+        the connect. The nonce mechanism requires no setup and is orthogonal to
+        the higher-level authentication mechanisms described in the
+        Authentication section.
+      </para>
+
+      <para>
+        On start, the server generates a random 16 byte nonce and writes it
+        to a file in the user's temporary directory. The nonce file location
+        is published as part of the server's D-Bus address using the
+        "noncefile" key-value pair.
+
+        After an accept, the server reads 16 bytes from the socket. If the
+        read bytes do not match the nonce stored in the nonce file, the
+        server MUST immediately drop the connection.
+        If the nonce match the received byte sequence, the client is accepted
+        and the transport behaves like an unsecured tcp transport.
+      </para>
+      <para>
+        After a successful connect to the server socket, the client MUST read
+        the nonce from the file published by the server via the noncefile=
+        key-value pair and send it over the socket. After that, the
+        transport behaves like an unsecured tcp transport.
+      </para>
+      <sect3 id="transports-nonce-tcp-sockets-addresses">
+        <title>Server Address Format</title>
+        <para> 
+         Nonce TCP/IP socket addresses uses the "nonce-tcp:" prefix 
+         and support the following key/value pairs:
+        </para>
+        <informaltable>
+         <tgroup cols="3">
+          <thead>
+           <row>
+            <entry>Name</entry>
+            <entry>Values</entry>
+            <entry>Description</entry>
+           </row>
+          </thead>
+          <tbody>
+           <row>
+            <entry>host</entry>
+            <entry>(string)</entry>
+            <entry>dns name or ip address</entry>
+          </row>
+          <row>
+           <entry>port</entry>
+           <entry>(number)</entry>
+           <entry>The tcp port the server will open. A zero value let the server 
+            choose a free port provided from the underlaying operating system. 
+            libdbus is able to retrieve the real used port from the server.  
+           </entry>
+          </row>
+          <row>
+           <entry>family</entry>
+           <entry>(string)</entry>
+           <entry>If set, provide the type of socket family either "ipv4" or "ipv6". If unset, the family is unspecified.</entry>
+          </row>
+          <row>
+           <entry>noncefile</entry>
+           <entry>(path)</entry>
+           <entry>file location containing the secret</entry>
+          </row>
+         </tbody>
+        </tgroup>
+       </informaltable>
+      </sect3>
+    </sect2>
+   </sect1>
+   <sect1 id="meta-transports">
+    <title>Meta Transports</title>
     <para>
-      Object paths are normally all lowercase with underscores used rather than
-      hyphens.
+      Meta transports are a kind of transport with special enhancements or
+      behavior. Currently available meta transports include: autolaunch
     </para>
-  </sect1>
+
+    <sect2 id="meta-transports-autolaunch">
+     <title>Autolaunch</title>
+     <para>The autolaunch transport provides a way for dbus clients to autodetect
+       a running dbus session bus and to autolaunch a session bus if not present.
+     </para>
+     <sect3 id="meta-transports-autolaunch-addresses">
+       <title>Server Address Format</title>
+       <para>
+         Autolaunch addresses uses the "autolaunch:" prefix and support the
+         following key/value pairs:
+       </para>
+       <informaltable>
+        <tgroup cols="3">
+         <thead>
+          <row>
+           <entry>Name</entry>
+           <entry>Values</entry>
+           <entry>Description</entry>
+          </row>
+         </thead>
+         <tbody>
+          <row>
+           <entry>scope</entry>
+           <entry>(string)</entry>
+           <entry>scope of autolaunch (Windows only)
+            <itemizedlist>
+             <listitem>
+              <para>
+               "*install-path" - limit session bus to dbus installation path.
+               The dbus installation path is determined from the location of
+               the shared dbus library. If the library is located in a 'bin'
+               subdirectory the installation root is the directory above,
+               otherwise the directory where the library lives is taken as
+               installation root.
+               <programlisting>
+                   &lt;install-root&gt;/bin/[lib]dbus-1.dll
+                   &lt;install-root&gt;/[lib]dbus-1.dll
+               </programlisting>
+              </para>
+             </listitem>
+             <listitem>
+              <para>
+               "*user" - limit session bus to the recent user.
+              </para>
+             </listitem>
+             <listitem>
+              <para>
+               other values - specify dedicated session bus like "release",
+               "debug" or other
+              </para>
+             </listitem>
+            </itemizedlist>
+           </entry>
+         </row>
+        </tbody>
+       </tgroup>
+      </informaltable>
+     </sect3>
+
+     <sect3 id="meta-transports-autolaunch-windows-implementation">
+      <title>Windows implementation</title>
+      <para>
+        On start, the server opens a platform specific transport, creates a mutex
+        and a shared memory section containing the related session bus address.
+        This mutex will be inspected by the dbus client library to detect a
+        running dbus session bus. The access to the mutex and the shared memory
+        section are protected by global locks.
+      </para>
+      <para>
+       In the recent implementation the autolaunch transport uses a tcp transport
+       on localhost with a port choosen from the operating system. This detail may
+       change in the future.
+      </para>
+      <para>
+        Disclaimer: The recent implementation is in an early state and may not
+        work in all cirumstances and/or may have security issues. Because of this
+        the implementation is not documentated yet.
+      </para>
+     </sect3>
+    </sect2>
+   </sect1>
 
   <sect1 id="uuids">
     <title>UUIDs</title>
         deterministic rule, or returning an error, are the reasonable 
         possibilities).
       </para>
+      <para>
+        If one or more properties change on an object, the
+        <literal>org.freedesktop.DBus.Properties.PropertiesChanged</literal>
+        signal may be emitted (this signal was added in 0.14):
+      </para>
+      <para>
+        <programlisting>
+              org.freedesktop.DBus.Properties.PropertiesChanged (STRING interface_name,
+                                                                 DICT&lt;STRING,VARIANT&gt; changed_properties,
+                                                                 ARRAY&lt;STRING&gt; invalidated_properties);
+        </programlisting>
+      </para>
+      <para>
+        where <literal>changed_properties</literal> is a dictionary
+        containing the changed properties with the new values and
+        <literal>invalidated_properties</literal> is an array of
+        properties that changed but the value is not conveyed.
+      </para>
+      <para>
+        Whether the <literal>PropertiesChanged</literal> signal is
+        supported can be determined by calling
+        <literal>org.freedesktop.DBus.Introspectable.Introspect</literal>. Note
+        that the signal may be supported for an object but it may
+        differ how whether and how it is used on a per-property basis
+        (for e.g. performance or security reasons). Each property (or
+        the parent interface) must be annotated with the
+        <literal>org.freedesktop.DBus.Property.EmitsChangedSignal</literal>
+        annotation to convey this (usually the default value
+        <literal>true</literal> is sufficient meaning that the
+        annotation does not need to be used). See <xref
+        linkend="introspection-format"/> for details on this
+        annotation.
+      </para>
     </sect2>
   </sect1>
 
             <entry>true,false</entry>
             <entry>If set, don't expect a reply to the method call; defaults to false.</entry>
           </row>
+          <row>
+            <entry>org.freedesktop.DBus.Property.EmitsChangedSignal</entry>
+            <entry>true,invalidates,false</entry>
+            <entry>
+               <para>
+                 If set to <literal>false</literal>, the
+                 <literal>org.freedesktop.DBus.Properties.PropertiesChanged</literal>
+                 signal, see <xref
+                 linkend="standard-interfaces-properties"/> is not
+                 guaranteed to be emitted if the property changes.
+               </para>
+               <para>
+                 If set to <literal>invalidates</literal> the signal
+                 is emitted but the value is not included in the
+                 signal.
+               </para>
+               <para>
+                 If set to <literal>true</literal> the signal is
+                 emitted with the value included.
+               </para>
+               <para>
+                 The value for the annotation defaults to
+                 <literal>true</literal> if the enclosing interface
+                 element does not specify the annotation. Otherwise it
+                 defaults to the value specified in the enclosing
+                 interface element.
+               </para>
+             </entry>
+          </row>
         </tbody>
        </tgroup>
      </informaltable>
         linkend="message-protocol-header-fields"/>).  If the
         <literal>DESTINATION</literal> field is present, it specifies a message
         recipient by name. Method calls and replies normally specify this field.
+        The message bus must send messages (of any type) with the
+        <literal>DESTINATION</literal> field set to the specified recipient,
+        regardless of whether the recipient has set up a match rule matching
+        the message.
       </para>
 
       <para>
            </tgroup>
          </informaltable>
         </para>
-      </sect3>
+       </sect3>
+
+       <sect3 id="bus-messages-list-queued-owners">
+        <title><literal>org.freedesktop.DBus.ListQueuedOwners</literal></title>
+        <para>
+          As a method:
+          <programlisting>
+            ARRAY of STRING ListQueuedOwners (in STRING name)
+          </programlisting>
+          Message arguments:
+          <informaltable>
+            <tgroup cols="3">
+              <thead>
+                <row>
+                  <entry>Argument</entry>
+                  <entry>Type</entry>
+                  <entry>Description</entry>
+                </row>
+              </thead>
+              <tbody>
+                <row>
+                  <entry>0</entry>
+                  <entry>STRING</entry>
+                  <entry>The well-known bus name to query, such as
+                    <literal>com.example.cappuccino</literal></entry>
+                </row>
+              </tbody>
+            </tgroup>
+          </informaltable>
+          Reply arguments:
+          <informaltable>
+            <tgroup cols="3">
+              <thead>
+                <row>
+                  <entry>Argument</entry>
+                  <entry>Type</entry>
+                  <entry>Description</entry>
+                </row>
+              </thead>
+              <tbody>
+                <row>
+                  <entry>0</entry>
+                  <entry>ARRAY of STRING</entry>
+                  <entry>The unique bus names of connections currently queued
+                    for the name</entry>
+                </row>
+              </tbody>
+            </tgroup>
+          </informaltable>
+        </para>
+        <para>
+          This method call should be sent to
+          <literal>org.freedesktop.DBus</literal> and lists the connections
+          currently queued for a bus name (see
+          <xref linkend="term-queued-owner"/>).
+        </para>
+       </sect3>
     </sect2>
 
     <sect2 id="message-bus-routing">
         </para>
         <para>
           Match rules are added using the AddMatch bus method 
-          (see xref linkend="bus-messages-add-match"/>).  Rules are 
+          (see <xref linkend="bus-messages-add-match"/>).  Rules are
           specified as a string of comma separated key/value pairs. 
           Excluding a key from the rule indicates a wildcard match.  
           For instance excluding the the member from a match rule but 
                   path match is path='/org/freedesktop/Hal/Manager'</entry>
                 </row>
                 <row>
+                  <entry><literal>path_namespace</literal></entry>
+                  <entry>An object path</entry>
+                  <entry>
+                    <para>
+                      Matches messages which are sent from or to an
+                      object for which the object path is either the
+                      given value, or that value followed by one or
+                      more path components.
+                    </para>
+
+                    <para>
+                      For example,
+                      <literal>path_namespace='/com/example/foo'</literal>
+                      would match signals sent by
+                      <literal>/com/example/foo</literal>
+                      or by
+                      <literal>/com/example/foo/bar</literal>,
+                      but not by
+                      <literal>/com/example/foobar</literal>.
+                    </para>
+
+                    <para>
+                      Using both <literal>path</literal> and
+                      <literal>path_namespace</literal> in the same match
+                      rule is not allowed.
+                    </para>
+
+                    <para>
+                      <emphasis>
+                        This match key was added in version 0.16 of the
+                        D-Bus specification and implemented by the bus
+                        daemon in dbus 1.5.0 and later.
+                      </emphasis>
+                    </para>
+                </entry>
+                </row>
+                <row>
                   <entry><literal>destination</literal></entry>
                   <entry>A unique name (see <xref linkend="term-unique-name"/>)</entry>
                   <entry>Matches messages which are being sent to the given unique name. An
                   <entry><literal>arg[0, 1, 2, 3, ...]</literal></entry>
                   <entry>Any string</entry>
                   <entry>Arg matches are special and are used for further restricting the 
-                  match based on the arguments in the body of a message.  As of this time
-                  only string arguments can be matched.  An example of an argument match 
+                  match based on the arguments in the body of a message. Only arguments of type
+                  STRING can be matched in this way. An example of an argument match 
                   would be arg3='Foo'. Only argument indexes from 0 to 63 should be 
                   accepted.</entry>
                 </row>
                 <row>
                   <entry><literal>arg[0, 1, 2, 3, ...]path</literal></entry>
                   <entry>Any string</entry>
-                  <entry>Argument path matches provide a specialised form of wildcard
-                  matching for path-like namespaces. As with normal argument matches,
-                  if the argument is exactly equal to the string given in the match
-                  rule then the rule is satisfied. Additionally, there is also a
-                  match when either the string given in the match rule or the
-                  appropriate message argument ends with '/' and is a prefix of the
-                  other. An example argument path match is arg0path='/aa/bb/'. This
-                  would match messages with first arguments of '/', '/aa/',
-                  '/aa/bb/', '/aa/bb/cc/' and '/aa/bb/cc'. It would not match
-                  messages with first arguments of '/aa/b', '/aa' or even '/aa/bb'.</entry>
+                  <entry>
+                    <para>Argument path matches provide a specialised form of wildcard matching for
+                      path-like namespaces. They can match arguments whose type is either STRING or
+                      OBJECT_PATH. As with normal argument matches,
+                      if the argument is exactly equal to the string given in the match
+                      rule then the rule is satisfied. Additionally, there is also a
+                      match when either the string given in the match rule or the
+                      appropriate message argument ends with '/' and is a prefix of the
+                      other. An example argument path match is arg0path='/aa/bb/'. This
+                      would match messages with first arguments of '/', '/aa/',
+                      '/aa/bb/', '/aa/bb/cc/' and '/aa/bb/cc'. It would not match
+                      messages with first arguments of '/aa/b', '/aa' or even '/aa/bb'.</para>
+
+                    <para>This is intended for monitoring “directories” in file system-like
+                      hierarchies, as used in the <citetitle>dconf</citetitle> configuration
+                      system. An application interested in all nodes in a particular hierarchy would
+                      monitor <literal>arg0path='/ca/example/foo/'</literal>. Then the service could
+                      emit a signal with zeroth argument <literal>"/ca/example/foo/bar"</literal> to
+                      represent a modification to the “bar” property, or a signal with zeroth
+                      argument <literal>"/ca/example/"</literal> to represent atomic modification of
+                      many properties within that directory, and the interested application would be
+                      notified in both cases.</para>
+                    <para>
+                      <emphasis>
+                        This match key was added in version 0.12 of the
+                        D-Bus specification, implemented for STRING
+                        arguments by the bus daemon in dbus 1.2.0 and later,
+                        and implemented for OBJECT_PATH arguments in dbus 1.5.0
+                        and later.
+                      </emphasis>
+                    </para>
+                  </entry>
+                </row>
+                <row>
+                  <entry><literal>arg0namespace</literal></entry>
+                  <entry>Like a bus name, except that the string is not
+                    required to contain a '.' (period)</entry>
+                  <entry>
+                    <para>Match messages whose first argument is of type STRING, and is a bus name
+                      or interface name within the specified namespace. This is primarily intended
+                      for watching name owner changes for a group of related bus names, rather than
+                      for a single name or all name changes.</para>
+
+                    <para>Because every valid interface name is also a valid
+                      bus name, this can also be used for messages whose
+                      first argument is an interface name.</para>
+
+                    <para>For example, the match rule
+                      <literal>member='NameOwnerChanged',arg0namespace='com.example.backend'</literal>
+                      matches name owner changes for bus names such as
+                      <literal>com.example.backend.foo</literal>,
+                      <literal>com.example.backend.foo.bar</literal>, and
+                      <literal>com.example.backend</literal> itself.</para>
+
+                    <para>See also <xref linkend='bus-messages-name-owner-changed'/>.</para>
+                    <para>
+                      <emphasis>
+                        This match key was added in version 0.16 of the
+                        D-Bus specification and implemented by the bus
+                        daemon in dbus 1.5.0 and later.
+                      </emphasis>
+                    </para>
+                  </entry>
                 </row>
               </tbody>
             </tgroup>
         <xref linkend="message-bus-types"/>.
       </para>
       <para>
-        [FIXME the file format should be much better specified than "similar to
-        .desktop entries" esp. since desktop entries are already
-        badly-specified. ;-)] Service description files have the ".service" file
+        Service description files have the ".service" file
         extension. The message bus will only load service description files
         ending with .service; all other files will be ignored.  The file format
         is similar to that of <ulink
-        url="http://www.freedesktop.org/standards/desktop-entry-spec/desktop-entry-spec.html">desktop
+        url="http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html">desktop
         entries</ulink>. All service description files must be in UTF-8
         encoding. To ensure that there will be no name collisions, service files
         must be namespaced using the same mechanism as messages and service
         names.
+      </para>
+
+      <para>
+        [FIXME the file format should be much better specified than "similar to
+        .desktop entries" esp. since desktop entries are already
+        badly-specified. ;-)]
+        These sections from the specification apply to service files as well:
+
+        <itemizedlist>
+          <listitem><para>General syntax</para></listitem>
+          <listitem><para>Comment format</para></listitem>
+        </itemizedlist>
 
         <figure>
          <title>Example service description file</title>
           The environment variable should have precedence over the 
           root window property.
         </para>
-        <para>
-          [FIXME specify location of .service files, probably using 
-          DESKTOP_DIRS etc. from basedir specification, though login session 
-          bus is not really desktop-specific]
-        </para>
+        <para>The address of the login session message bus is given in the
+        <literal>DBUS_SESSION_BUS_ADDRESS</literal> environment variable. If
+        DBUS_SESSION_BUS_ADDRESS is not set, or if it's set to the string
+        "autolaunch:", the system should use platform-specific methods of
+        locating a running D-Bus session server, or starting one if a running
+        instance cannot be found. Note that this mechanism is not recommended
+        for attempting to determine if a daemon is running. It is inherently
+        racy to attempt to make this determination, since the bus daemon may
+        be started just before or just after the determination is made.
+        Therefore, it is recommended that applications do not try to make this
+        determination for their functionality purposes, and instead they
+        should attempt to start the server.</para>
+
+        <sect4 id="message-bus-types-login-x-windows">
+          <title>X Windowing System</title>
+          <para>
+            For the X Windowing System, the application must locate the
+            window owner of the selection represented by the atom formed by
+            concatenating:
+            <itemizedlist>
+              <listitem>
+                <para>the literal string "_DBUS_SESSION_BUS_SELECTION_"</para>
+              </listitem>
+
+              <listitem>
+                <para>the current user's username</para>
+              </listitem>
+
+              <listitem>
+                <para>the literal character '_' (underscore)</para>
+              </listitem>
+
+              <listitem>
+                <para>the machine's ID</para>
+              </listitem>
+            </itemizedlist>
+          </para>
+
+          <para>
+            The following properties are defined for the window that owns
+            this X selection:
+            <informaltable frame="all">
+              <tgroup cols="2">
+                <tbody>
+                  <row>
+                    <entry>
+                      <para>Atom</para>
+                    </entry>
+
+                    <entry>
+                      <para>meaning</para>
+                    </entry>
+                  </row>
+
+                  <row>
+                    <entry>
+                      <para>_DBUS_SESSION_BUS_ADDRESS</para>
+                    </entry>
+
+                    <entry>
+                      <para>the actual address of the server socket</para>
+                    </entry>
+                  </row>
+
+                  <row>
+                    <entry>
+                      <para>_DBUS_SESSION_BUS_PID</para>
+                    </entry>
+
+                    <entry>
+                      <para>the PID of the server process</para>
+                    </entry>
+                  </row>
+                </tbody>
+              </tgroup>
+            </informaltable>
+          </para>
+
+          <para>
+            At least the _DBUS_SESSION_BUS_ADDRESS property MUST be
+            present in this window.
+          </para>
+
+          <para>
+            If the X selection cannot be located or if reading the
+            properties from the window fails, the implementation MUST conclude
+            that there is no D-Bus server running and proceed to start a new
+            server. (See below on concurrency issues)
+          </para>
+
+          <para>
+            Failure to connect to the D-Bus server address thus obtained
+            MUST be treated as a fatal connection error and should be reported
+            to the application.
+          </para>
+
+          <para>
+            As an alternative, an implementation MAY find the information
+            in the following file located in the current user's home directory,
+            in subdirectory .dbus/session-bus/:
+            <itemizedlist>
+              <listitem>
+                <para>the machine's ID</para>
+              </listitem>
+
+              <listitem>
+                <para>the literal character '-' (dash)</para>
+              </listitem>
+
+              <listitem>
+                <para>the X display without the screen number, with the
+                following prefixes removed, if present: ":", "localhost:"
+                ."localhost.localdomain:". That is, a display of
+                "localhost:10.0" produces just the number "10"</para>
+              </listitem>
+            </itemizedlist>
+          </para>
+
+          <para>
+            The contents of this file NAME=value assignment pairs and
+            lines starting with # are comments (no comments are allowed
+            otherwise). The following variable names are defined:
+            <informaltable
+              frame="all">
+              <tgroup cols="2">
+                <tbody>
+                  <row>
+                    <entry>
+                      <para>Variable</para>
+                    </entry>
+
+                    <entry>
+                      <para>meaning</para>
+                    </entry>
+                  </row>
+
+                  <row>
+                    <entry>
+                      <para>DBUS_SESSION_BUS_ADDRESS</para>
+                    </entry>
+
+                    <entry>
+                      <para>the actual address of the server socket</para>
+                    </entry>
+                  </row>
+
+                  <row>
+                    <entry>
+                      <para>DBUS_SESSION_BUS_PID</para>
+                    </entry>
+
+                    <entry>
+                      <para>the PID of the server process</para>
+                    </entry>
+                  </row>
+
+                  <row>
+                    <entry>
+                      <para>DBUS_SESSION_BUS_WINDOWID</para>
+                    </entry>
+
+                    <entry>
+                      <para>the window ID</para>
+                    </entry>
+                  </row>
+                </tbody>
+              </tgroup>
+            </informaltable>
+          </para>
+
+          <para>
+            At least the DBUS_SESSION_BUS_ADDRESS variable MUST be present
+            in this file.
+          </para>
+
+          <para>
+            Failure to open this file MUST be interpreted as absence of a
+            running server. Therefore, the implementation MUST proceed to
+            attempting to launch a new bus server if the file cannot be
+            opened.
+          </para>
+
+          <para>
+            However, success in opening this file MUST NOT lead to the
+            conclusion that the server is running. Thus, a failure to connect to
+            the bus address obtained by the alternative method MUST NOT be
+            considered a fatal error. If the connection cannot be established,
+            the implementation MUST proceed to check the X selection settings or
+            to start the server on its own.
+          </para>
+
+          <para>
+            If the implementation concludes that the D-Bus server is not
+            running it MUST attempt to start a new server and it MUST also
+            ensure that the daemon started as an effect of the "autolaunch"
+            mechanism provides the lookup mechanisms described above, so
+            subsequent calls can locate the newly started server. The
+            implementation MUST also ensure that if two or more concurrent
+            initiations happen, only one server remains running and all other
+            initiations are able to obtain the address of this server and
+            connect to it. In other words, the implementation MUST ensure that
+            the X selection is not present when it attempts to set it, without
+            allowing another process to set the selection between the
+            verification and the setting (e.g., by using XGrabServer /
+            XungrabServer).
+          </para>
+        </sect4>
+        <sect4>
+          <title></title>
+          <para>
+            [FIXME specify location of .service files, probably using
+            DESKTOP_DIRS etc. from basedir specification, though login session
+            bus is not really desktop-specific]
+          </para>
+        </sect4>
       </sect3>
       <sect3 id="message-bus-types-system">
         <title>System message bus</title>
 
       </sect3>
 
+      <sect3 id="bus-messages-update-activation-environment">
+        <title><literal>org.freedesktop.DBus.UpdateActivationEnvironment</literal></title>
+        <para>
+          As a method:
+          <programlisting>
+            UpdateActivationEnvironment (in ARRAY of DICT&lt;STRING,STRING&gt; environment)
+          </programlisting>
+          Message arguments:
+          <informaltable>
+            <tgroup cols="3">
+              <thead>
+                <row>
+                  <entry>Argument</entry>
+                  <entry>Type</entry>
+                  <entry>Description</entry>
+                </row>
+              </thead>
+              <tbody>
+                <row>
+                  <entry>0</entry>
+                  <entry>ARRAY of DICT&lt;STRING,STRING&gt;</entry>
+                  <entry>Environment to add or update</entry>
+                </row>
+              </tbody>
+            </tgroup>
+            </informaltable>
+            Normally, session bus activated services inherit the environment of the bus daemon.  This method adds to or modifies that environment when activating services.
+        </para>
+        <para>
+          Some bus instances, such as the standard system bus, may disable access to this method for some or all callers.
+        </para>
+        <para>
+          Note, both the environment variable names and values must be valid UTF-8.  There's no way to update the activation environment with data that is invalid UTF-8.
+        </para>
+
+      </sect3>
+
       <sect3 id="bus-messages-get-name-owner">
         <title><literal>org.freedesktop.DBus.GetNameOwner</literal></title>
         <para>
         <para>
           As a method:
           <programlisting>
-            UINT32 GetConnectionUnixUser (in STRING connection_name)
+            UINT32 GetConnectionUnixUser (in STRING bus_name)
           </programlisting>
           Message arguments:
           <informaltable>
                 <row>
                   <entry>0</entry>
                   <entry>STRING</entry>
-                  <entry>Name of the connection to query</entry>
+                  <entry>Unique or well-known bus name of the connection to
+                    query, such as <literal>:12.34</literal> or
+                    <literal>com.example.tea</literal></entry>
                 </row>
               </tbody>
             </tgroup>
               <row>
                 <entry>0</entry>
                 <entry>UINT32</entry>
-                <entry>unix user id</entry>
+                <entry>Unix user ID</entry>
               </row>
             </tbody>
           </tgroup>
         </informaltable>
-        Returns the unix uid of the process connected to the server. If unable to
-       determine it, a <literal>org.freedesktop.DBus.Error.Failed</literal>
-       error is returned.
+        Returns the Unix user ID of the process connected to the server. If
+        unable to determine it (for instance, because the process is not on the
+        same machine as the bus daemon), an error is returned.
+       </para>
+      </sect3>
+
+      <sect3 id="bus-messages-get-connection-unix-process-id">
+        <title><literal>org.freedesktop.DBus.GetConnectionUnixProcessID</literal></title>
+        <para>
+          As a method:
+          <programlisting>
+            UINT32 GetConnectionUnixProcessID (in STRING bus_name)
+          </programlisting>
+          Message arguments:
+          <informaltable>
+            <tgroup cols="3">
+              <thead>
+                <row>
+                  <entry>Argument</entry>
+                  <entry>Type</entry>
+                  <entry>Description</entry>
+                </row>
+              </thead>
+              <tbody>
+                <row>
+                  <entry>0</entry>
+                  <entry>STRING</entry>
+                  <entry>Unique or well-known bus name of the connection to
+                    query, such as <literal>:12.34</literal> or
+                    <literal>com.example.tea</literal></entry>
+                </row>
+              </tbody>
+            </tgroup>
+          </informaltable>
+        Reply arguments:
+        <informaltable>
+          <tgroup cols="3">
+            <thead>
+              <row>
+                <entry>Argument</entry>
+                <entry>Type</entry>
+                <entry>Description</entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>0</entry>
+                <entry>UINT32</entry>
+                <entry>Unix process id</entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
+        Returns the Unix process ID of the process connected to the server. If
+        unable to determine it (for instance, because the process is not on the
+        same machine as the bus daemon), an error is returned.
        </para>
       </sect3>
 
 
   </glossary>
 </article>
-