fdo-mirrors/dbus
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/dbus/dbus.git synced 2026-01-06 10:40:14 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

spec: Mention that the system bus address might actually be in /run

Browse source 
The interoperable address is unix:path=/var/run/dbus/system_bus_socket.
However, in most (perhaps all) current Linux distributions, /var/run
is guaranteed to be a symbolic link to /run, and using the path in /run
has some advantages (particularly if automounters are used).

Implementations that intend to be interoperable are not required to
listen on exactly /var/run/dbus/system_bus_socket, as long as clients
that connect to that socket will work correctly. Similarly, clients
are not required to connect to exactly /var/run/dbus/system_bus_socket,
as long as the overall system (consisting of the client and the OSs
that it supports) ensures that it ends up connecting to the same
well-known system bus that is available at
/var/run/dbus/system_bus_socket.

Because of the Unix conventions for how software installs into a prefix,
building a D-Bus implementation with its default build-time
configuration options will not necessarily result in an interoperable
system bus. The system bus is normally shipped by OS distributors,
who should ensure that they have configured it in a way that is
interoperable.

Resolves: https://gitlab.freedesktop.org/dbus/dbus/-/issues/180
Signed-off-by: Simon McVittie <smcv@collabora.com>
This commit is contained in:
Simon McVittie 2022-07-15 17:10:57 +01:00
parent 91fe77904a
commit cc0544cd36
1 changed files with 21 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
doc/dbus-specification.xml
View file

@ -5783,13 +5783,27 @@
variable. If that variable is not set, applications should try
to connect to the well-known address
<literal>unix:path=/var/run/dbus/system_bus_socket</literal>.
<footnote>
<para>
The D-Bus reference implementation actually honors the
<literal>$(localstatedir)</literal> configure option
for this address, on both client and server side.
</para>
</footnote>
Implementations of the well-known system bus should listen on
an address that will result in that connection being successful.
</para>
<para>
On systems where <filename>/var/run/</filename> is known to be
synonymous with <filename>/run/</filename> (such as most Linux
operating system distributions), implementations might prefer
to make use of that knowledge to connect to or listen on
<literal>unix:path=/run/dbus/system_bus_socket</literal> instead,
which has some minor technical advantages, particularly during
early startup and late shutdown.
</para>
<para>
In practice, implementations of D-Bus often have build-time
configuration options for the system bus address, whose defaults
often depend on other build-time options such as the installation
prefix (in particular, this is the case for dbus, the reference
implementation of D-Bus).
Distributors intending to provide access to the well-known
system bus should verify that they are using an interoperable
address.
</para>
<para>
On Unix systems, the system bus should default to searching