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.
Let's fold get_user_creds_clean() into get_user_creds(), and introduce a
flags argument for it to select "clean" behaviour. This flags parameter
also learns to other new flags:
- USER_CREDS_SYNTHESIZE_FALLBACK: in this mode the user records for
root/nobody are only synthesized as fallback. Normally, the synthesized
records take precedence over what is in the user database. With this
flag set this is reversed, and the user database takes precedence, and
the synthesized records are only used if they are missing there. This
flag should be set in cases where doing NSS is deemed safe, and where
there's interest in knowing the correct shell, for example if the
admin changed root's shell to zsh or suchlike.
- USER_CREDS_ALLOW_MISSING: if set, and a UID/GID is specified by
numeric value, and there's no user/group record for it accept it
anyway. This allows us to fix#9767
This then also ports all users to set the most appropriate flags.
Fixes: #9767
[zj: remove one isempty() call]
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.
For now, only add_acls_for_user is tested. When run under root, it
actually sets the acls. When run under non-root, it sets the acls for
the user, which does nothing, but at least calls the functions.
