Realistically, the only thing that the caller can do is ignore failures related
to missing credentials. If the caller requires some credentials to be present,
they should just check which output variables are not NULL. One of the callers
was already doing that, and the other wanted to, but missed -ENOENT. By
suppressing -ENOENT and -ENXIO, both callers are simplified.
Fixes a warning at boot:
systemd-vconsole-setup[221]: Failed to import credentials, ignoring: No such file or directory
Unfortunately we can't escape $ when ':' is used to prohibit variable expansion:
ExecStart=:echo $$
is not the same as
ExecStart=:echo $
This just adds the functionality and the unittests, without using it anywhere
for real yet.
Our escaping of '$' is '$$', not '\$'. We would write unit files that
were not valid:
$ systemd-run --user bash -c 'echo $$; sleep 1000'
Running as unit: run-r1c7c45b5b69f487c86ae205e12100808.service
$ systemctl cat --user run-r1c7c45b5b69f487c86ae205e12100808
# /run/user/1000/systemd/transient/run-r1c7c45b5b69f487c86ae205e12100808.service
...
ExecStart="/usr/bin/bash" "-c" "echo \$\$\; sleep 1000"
$ systemd-analyze verify /run/user/1000/systemd/transient/run-r1c7c45b5b69f487c86ae205e12100808.service
/run/user/1000/systemd/transient/run-r1c7c45b5b69f487c86ae205e12100808.service:7:
Ignoring unknown escape sequences: "echo \$\$\; sleep 1000"
Similarly, ';' cannot be escaped as '\;'. Only a handful of characters
listed in "Supported escapes" is allowed.
Escaping of "'" can be done, but it's not useful because we use double quotes
around the string anyway whenever we do escaping.
unit_write_setting() is called all over the place. In a great majority of
places we write either fixed strings or something that we generate ourselves,
so no escaping or quoting is needed. (And it's not allowed, e.g.
'Type="oneshot"' would not work.) But if we forgot to add escaping or quoting
for a free-style string, it would probably allow writing a unit file that would
be read completely wrong. I looked over various places where
unit_write_setting() is called, and I couldn't find any place where
quoting/escaping was forgotten. But trying to figure out the full
ramifications of this change is not easy.
__builtin_popcount() is a bit of a mouthful, so let's provide a helper.
Using _Generic has the advantage that if a type other then the ones on
the list is given, compilation will fail. This is nice, because if by any
change we pass a wider type, it is rejected immediately instead of being
truncated.
log.h is also needed. It is included transitively, but let's include it
directly.
macro.h is *not* needed.
The function path_prefix_root_cwd() was introduced for prefixing the
result from chaseat() with root, but
- it is named slightly generic,
- the logic is different from what chase() does.
This makes the name more explanative and specific for the result of the
chaseat(), and make the logic consistent with chase().
Fixes https://github.com/systemd/systemd/pull/27199#issuecomment-1511387731.
Follow-up for #27199.
Usually, we pass the file descriptor of the root directory to chaseat()
when `--root=` is not specified. Previously, even in such case, the
result was relative, and we need to prefix the path with "/" when we
want to pass the path to other functions that do not support dir_fd, or
log or show the path. That's inconvenient.
The ignore directive specifies to not do anything with the given
unit and leave existing configuration intact. This allows distributions
to gradually adopt preset files by shipping a ignore * preset file.
strstrafter() is like strstr() but returns a pointer to the first
character *after* the found substring, not on the substring itself.
Quite often this is what we actually want.
Inspired by #27267 I think it makes sense to add a helper for this,
to avoid the potentially fragile manual pointer increment afterwards.
When CHASE_MKDIR_0755 is specified without CHASE_NONEXISTENT and
CHASE_PARENT, then chase() succeeds only when the file specified by
the path already exists, and in that case, chase() does not create
any parent directories, and CHASE_MKDIR_0755 is meaningless.
Let's mention that CHASE_MKDIR_0755 needs to be specified with
CHASE_NONEXISTENT or CHASE_PARENT, and adds a assertion about that.
Enabling these options when not running as root requires a user
namespace, so implicitly enable PrivateUsers=.
This has a side effect as it changes which users are visible to the unit.
However until now these options did not work at all for user units, and
in practice just a handful of user units in Fedora, Debian and Ubuntu
mistakenly used them (and they have been all fixed since).
This fixes the long-standing confusing issue that the user and system
units take the same options but the behaviour is wildly (and sometimes
silently) different depending on which is which, with user units
requiring manually specifiying PrivateUsers= in order for sandboxing
options to actually work and not be silently ignored.
For consistency with other functions.
Unfortunately, va_start() requires that the previous argument is a
pointer, hence the order of the arguments in the internal function
cannot be changed.
When path_find_first_component() returns the last component, the iterator
must be an empty string. The fact is heavily used in chaseat(). Let's
explicitly test it.
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Luca Boccassi
David Tardon
Yu Watanabe
Frantisek Sumsal
Daan De Meyer
OMOJOLA JOSHUA DAMILOLA
Tanishka
maanyagoenka