This way it is easy to only exclude directories from the current boot
from automatic clean up in /var/tmp.
Also, pick a longer name for the directories so that are globs in
tmp.conf can be simpler yet equally accurate.
Currently, PrivateTmp=yes means that the service cannot see the /tmp
shared by rest of the system and is isolated from other services using
PrivateTmp, but users can access and modify /tmp as seen by the
service.
Move the private /tmp and /var/tmp directories into a 0077-mode
directory. This way unpriviledged users on the system cannot see (or
modify) /tmp as seen by the service.
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
Many people prefer to avoid clearing /tmp and /var/tmp, and
distributions often have explicit settings for how often to clear them
if at all. Overriding those with systemd currently requires overriding
all of /usr/lib/tmpfiles.d/systemd.conf via
/etc/tmpfiles.d/systemd.conf, copying across all the other entries, and
updating that override when systemd.conf changes.
Move the /tmp and /var/tmp entries from systemd.conf to a separate
tmp.conf, making them easier to override without affecting the rest of
systemd.conf.
