So here's the thing. One library we use (libselinux) is opening fds
behind our back when we initialize it and keeps it open. On the other
hand we want to automatically pick up all fds passed in to us, so that
we can distribute them to our services and close the rest. We pick them
up very early in our code, to ensure that we don't get confused by open
fds at that point. Except that libselinux insists on being initialized
even earlier. So suddenly we might take possession of libselinux' fds,
and then close them later when we decide no service wants them. Then
during shutdown we close down selinux and selinux closes its fds, but
since already closed long ago this ight close our fds instead. Hilarity
ensues.
I wish low-level software wouldn't do such things behind our back, but
well, let's make the best of it.
This changes the fd pick-up logic to only pick up fds that have
O_CLOEXEC unset. O_CLOEXEC must be unset for any fds passed in to us
over execve() after all. And for all our own fds we should set O_CLOEXEC
since we generally don't want to litter fd tables for execve(). Also,
libselinux thankfully appears to set O_CLOEXEC correctly on its fds,
hence the filter works.
Fixes: #27491
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
This converts to TEST macro where it is trivial.
Some additional notable changes:
- simplify HAVE_LIBIDN #ifdef in test-dns-domain.c
- use saved_argc/saved_argv in test-copy.c, test-path-util.c,
test-tmpfiles.c and test-unit-file.c
This splits out a bunch of functions from fileio.c that have to do with
temporary files. Simply to make the header files a bit shorter, and to
group things more nicely.
No code changes, just some rearranging of source files.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
According to its manual page, flags given to mkostemp(3) shouldn't include
O_RDWR, O_CREAT or O_EXCL flags as these are always included. Beyond
those, the only flag that all callers (except a few tests where it
probably doesn't matter) use is O_CLOEXEC, so set that unconditionally.
Mike Yuan
Lennart Poettering
David Tardon
Zbigniew Jędrzejewski-Szmek
Jan Janssen
Yu Watanabe
Topi Miettinen
Ronny Chevalier