etc-gentoo/dbus-1/session.conf

<!-- This configuration file controls the per-user-login-session message bus.
     Add a session-local.conf and edit that rather than changing this 
     file directly. -->

<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-Bus Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <!-- Our well-known bus type, don't change this -->
  <type>session</type>

  <!-- If we fork, keep the user's original umask to avoid affecting
       the behavior of child processes. -->
  <keep_umask/>

  <listen>unix:tmpdir=/tmp</listen>

  <standard_session_servicedirs />

  <policy context="default">
    <!-- Allow everything to be sent -->
    <allow send_destination="*" eavesdrop="true"/>
    <!-- Allow everything to be received -->
    <allow eavesdrop="true"/>
    <!-- Allow anyone to own anything -->
    <allow own="*"/>
  </policy>

  <!-- Config files are placed here that among other things, 
       further restrict the above policy for specific services. -->
  <includedir>session.d</includedir>

  <!-- This is included last so local configuration can override what's 
       in this standard file -->
  <include ignore_missing="yes">session-local.conf</include>

  <include if_selinux_enabled="yes" selinux_root_relative="yes">contexts/dbus_contexts</include>

  <!-- For the session bus, override the default relatively-low limits 
       with essentially infinite limits, since the bus is just running 
       as the user anyway, using up bus resources is not something we need 
       to worry about. In some cases, we do set the limits lower than 
       "all available memory" if exceeding the limit is almost certainly a bug, 
       having the bus enforce a limit is nicer than a huge memory leak. But the 
       intent is that these limits should never be hit. -->

  <!-- the memory limits are 1G instead of say 4G because they can't exceed 32-bit signed int max -->
  <limit name="max_incoming_bytes">1000000000</limit>
  <limit name="max_incoming_unix_fds">250000000</limit>
  <limit name="max_outgoing_bytes">1000000000</limit>
  <limit name="max_outgoing_unix_fds">250000000</limit>
  <limit name="max_message_size">1000000000</limit>
  <!-- We do not override max_message_unix_fds here since the in-kernel
       limit is also relatively low -->
  <limit name="service_start_timeout">120000</limit>  
  <limit name="auth_timeout">240000</limit>
  <limit name="pending_fd_timeout">150000</limit>
  <limit name="max_completed_connections">100000</limit>  
  <limit name="max_incomplete_connections">10000</limit>
  <limit name="max_connections_per_user">100000</limit>
  <limit name="max_pending_service_starts">10000</limit>
  <limit name="max_names_per_connection">50000</limit>
  <limit name="max_match_rules_per_connection">50000</limit>
  <limit name="max_replies_per_connection">50000</limit>

</busconfig>