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.
This cleans up handling of MTU values across the codebase. Previously
MTU values where stored sometimes in uint32_t, sometimes in uint16_t,
sometimes unsigned and sometimes in size_t. This now unifies this to
uint32_t across the codebase, as that's what netlink spits out, and what
the majority was already using.
Also, all MTU parameters are now parsed with config_parse_mtu() and
config_parse_ipv6_mtu() is dropped as it is now unneeded.
(Note there is one exception for the MTU typing: in the DCHPv4 code we
continue to process the MTU as uint16_t value, as it is encoded like
that in the protocol, and it's probably better stay close to the
protocol there.)
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.
log.h really should only include the bare minimum of other headers, as
it is really pulled into pretty much everything else and already in
itself one of the most basic pieces of code we have.
Let's hence drop inclusion of:
1. sd-id128.h because it's entirely unneeded in current log.h
2. errno.h, dito.
3. sys/signalfd.h which we can replace by a simple struct forward
declaration
4. process-util.h which was needed for getpid_cached() which we now hide
in a funciton log_emergency_level() instead, which nicely abstracts
the details away.
5. sys/socket.h which was needed for struct iovec, but a simple struct
forward declaration suffices for that too.
Ultimately this actually makes our source tree larger (since users of
the functionality above must now include it themselves, log.h won't do
that for them), but I think it helps to untangle our web of includes a
tiny bit.
(Background: I'd like to isolate the generic bits of src/basic/ enough
so that we can do a git submodule import into casync for it)
