Originally by: Ivan Shmakov ivan@siamics.net
Posted to: alt.sources
On: Sat, 28 Jul 2018 12:07:38 +0000
Message-ID: 87bmarbm2d.fsf@violet.siamics.net
Archive-name: no-dbus-perl-2018-is
Copyright-Notice: Both this README and the code are available under CC0 Public Domain Dedication 1.0; see http://creativecommons.org/publicdomain/zero/1.0/.
This copy put on github as
https://github.com/Eli-the-Bearded/no-dbus
because I think github is a better place to find and share source code in the 2010s than an alt newsgroup. -- EtB
Note from the original author:
[Followup-To: set to news:alt.sources.d, as per the news:alt.sources charter, and also to news:comp.os.linux.misc. I will also monitor news:comp.lang.perl.misc, in case someone would wish to comment on the coding style or some such.]
# rm -- /run/dbus/system_bus_socket || mkdir -v -- /run/dbus
# chown -- nobody /run/dbus
# setsid -- su nobody -c perl\ no-dbus.perl &
When X.Org X server (at least as of version 1.19.2) is built with D-Bus support, such as the case for Debian 9 "Stretch," it logs every failure to connect to the D-Bus server, and also reattempts such connections every 10 seconds or so, resulting in the log growing by about 191 octets every 10 seconds (or 1.57 MiB/day) until and unless a connection is successfully established. (Cf. [1, 2].)
Seemingly, the lack of active D-Bus connection also reduces the X server performance.
Neither the documentation nor the source (at least for 1.19.2) seem to hint at a possibility of disabling D-Bus support by some run-time option. From there, available solutions are as follows.
-
Run a system D-Bus server on the machine. Cons.: one needs to learn the why and how X server (and possibly other installed software) uses D-Bus and take it into account when troubleshooting; also, as any software, said server may have (and probably has) unidentified bugs, including those that can be exploited by a malicious party.
-
Redirect the log to
/dev/null(e. g.,-logfile /dev/null.) Cons.: this also loses the valuable log messages; the X server performance may still be affected. -
Do nothing. Perhaps restart X server once in a while, so the log gets rotated (and older copies lost.) Cons.: inconvenient; performance may still be affected.
-
Run a simplistic server, which will answer as necessary to the handshake performed by X server, but will otherwise do nothing. Cons.: takes time and effort to get it right.
The present no-dbus.perl server implements the last of the above.
[1] xorg flooded by dbus messages // Debian Bug report logs http://bugs.debian.org/868453 [2] /var/log/Xorg.0.log gets flooded with (EE) dbus-... http://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1562610
Not tested with other software which may demand a running D-Bus daemon instance.
The "Hello" handshake handling is a hack. First of all, it searches for magic strings in the request (in place of proper decoding.) Then, I haven't figured out how to produce a correct response (see the commented-out my $reply section in the code) and just put in the code the one which a "real" D-Bus server emits.
Native octet order is assumed.
No --no-debug option.
A copy is not yet available from under http://am-1.org/~ivan/src/.
This README documents no-dbus.perl 0.1 (2017.U44uEkvB, authored 2017-12-16 17:53:34Z.)