This is not very pretty, but the code in fs-util.c already provisions for
missing /proc. We ourselves are careful to set up /proc, but not everybody
is and it is important for sysusers to also work where shadow-utils would:
I would like to replace calls to useradd and groupadd in Fedora systemd rpm
scriptlets with a call to sysusers. It has a number of advantages:
- dogfooding
- we don't need to manually duplicate the information from our sysusers
files to scriptlets
- a dependency on shadow-utils is dropped, which transitively drops dependencies
on setup and fedora-repos and bunch of other stuff.
We could try to get 'dnf' and 'rpm --root' and such to be reworked,
but not in any reasonable timeframe. And even if this was done, we'd still
want to support older rpm/dnf versions.
I'm trying to use systemd-sysusers for systemd.rpm itself, and the invocation
in dnf chroot is failing like this:
...
Creating group input with gid 999.
Creating group kvm with gid 36.
Creating group render with gid 998.
Creating group sgx with gid 997.
Creating group systemd-journal with gid 190.
Creating group systemd-network with gid 192.
Creating user systemd-network (systemd Network Management) with uid 192 and gid 192.
Creating group systemd-oom with gid 996.
Creating user systemd-oom (systemd Userspace OOM Killer) with uid 996 and gid 996.
Creating group systemd-resolve with gid 193.
Creating user systemd-resolve (systemd Resolver) with uid 193 and gid 193.
Creating group systemd-timesync with gid 995.
Creating user systemd-timesync (systemd Time Synchronization) with uid 995 and gid 995.
Creating group systemd-coredump with gid 994.
Creating user systemd-coredump (systemd Core Dumper) with uid 994 and gid 994.
Failed to write files: Function not implemented
Let's add more info to make such failures easier to debug.
We usually call specifier_printf() and then check the validity of
the result. In many cases, validity checkers, e.g. path_is_valid(),
refuse too long strings. This makes specifier_printf() refuse such
long results earlier.
Moreover, unit_full_string() and description field in sysuser now
refuse results longer than LONG_LINE_MAX. config_parse() already
refuses the line longer than LONG_LINE_MAX. Hence, it should be ok
to set the same value as the maximum length of the resolved string.
Let's add three defines for the 3 special cases of passwords.
Some of our tools used different values for the "locked"/"invalid" case,
let's settle on using "!*" which means the password is both locked *and*
invalid.
Other tools like to use "!!" for this case, which however is less than
ideal I think, since the this could also be a considered an entry with
an empty password, that can be enabled again by unlocking it twice.
Let's enable this in all tools that intend to write to the OS images.
It's not conditionalized for now, as there already is conditionalization
in the existance or absence of the flag in the GPT partition table (and
it's opt-in), hence it should be OK to just enable this by default for
now if the flag is set.
Let's make use of our own credentials infrastructure in our tools: let's
hook up systemd-sysusers with the credentials logic, so that the root
password can be provisioned this way. This is really useful when working
with stateless systems, in particular nspawn's "--volatile=yes" switch,
as this works now:
# systemd-nspawn -i foo.raw --volatile=yes --set-credential=passwd.plaintext-password:foo
For the first time we have a nice, non-interactive way to provision the
root password for a fully stateless system from the container manager.
Yay!
Previously, the flag did two things at once: enable support for using
generic partitions as root fs if there were only one/allow use of
partition-table-less images as root fs. And secondly, insist that there
was a rootfs, and fail if not. Let's split these two in two separate
options so that they can be used independently of each other.
There are cases where one wants to use one without the other (i.e. when
inspecting things with systemd-dissect tool it should be OK to do so
even if image has no root fs), and it's cleaner anyway.
It's so similar to copy_access(), hence let's move it over and rename it
in similar style to the rest of the functions.
No change in behaviour, just moving things over.
I think this formatting was originally used because it simplified
adding new options to the help messages. However, these days, most
tools their help message end with "\nSee the %s for details.\n" so
the final line almost never has to be edited which eliminates the
benefit of the custom formatting used for printf() help messages.
Let's make things more consistent and use the same formatting for
printf() help messages that we use everywhere else.
Prompted by https://github.com/systemd/systemd/pull/18355#discussion_r567241580
In many cases the tables are largely the same, hence define a common set
of macros to generate the common parts.
This adds in a couple of missing specifiers here and there, so is more
thant just refactoring: it actually fixes accidental omissions.
Note that some entries that look like they could be unified under these
macros can't really be unified, since they are slightly different. For
example in the DNSSD service logic we want to use the DNSSD hostname for
%H rather than the unmodified kernel one.
*** Running /home/zbyszek/src/systemd-work/test/test-sysusers/test-14.input (with login.defs symlinked)
login.defs specifies UID allocation range 401–555 that is different than the built-in defaults (201–998)
login.defs specifies GID allocation range 405–666 that is different than the built-in defaults (201–990)
Also, even if login.defs are not present, don't start allocating at 1, but at
SYSTEM_UID_MIN.
Fixes#9769.
The test is adjusted. Actually, it was busted before, because sysusers would
never use SYSTEM_GID_MIN, so if SYSTEM_GID_MIN was different than
SYSTEM_UID_MIN, the tests would fail. On all "normal" systems the two are
equal, so we didn't notice. Since sysusers now always uses the minimum of the
two, we only need to substitute one value.
This basically implements fc58c0c7bf for gshadow.
gpasswd may not have a lock/unlock that behaves the same as passwd, but
according to gshadow(5) the logic of the password field is the same.
As described in #15603, it is a fairly common setup to use a fqdn as the
configured hostname. But it is often convenient to use just the actual
hostname, i.e. until the first dot. This adds support in tmpfiles, sysusers,
and unit files for %l which expands to that.
Fixes#15603.
Let's use "!*" instead of "!!" as invalid password string.
Generally, any invalid password string can be used to for locking an
account, according to shadow(5). To temporarily lock a password of an
account it is commonly implemented to prefix the original password with
a single "!", so that it can later on be unlocked again by removing the
"!", restoring the original password. Thus, the "!" marker is an
indicator for a locked password; the act of prefixing "!" to a
password string is the locking operation; and the removal of a "!"
prefix is the unlock operation. (This is also suggested in shadow(5)).
If we want to entirely lock an account we previously used "!!" as
password string. This is nice since it indicates the password is locked.
However, it is less than ideal, since applying the password unlock
operation once will change the string to "!", which is still a locked
password. Unlocking the password a second time will result in "", i.e.
the empty password, which will in many cases allow logging in without
password. And that's a problem. Hopefully, tools do not allow such
duplicate unlocking, but it's still not a nice property.
By changing our password string to "!*" we get different behaviour: the
password will appear locked. When it is unlocked the password is "*"
which is an invalid password. In that case the password is hence
unlocked but invalid, which is a much better state to be in than the
above.
This is paranoia hardening. Not more. There's no report that anyone
every unlocked an account twice and people could log in.
This reworks the user validation infrastructure. There are now two
modes. In regular mode we are strict and test against a strict set of
valid chars. And in "relaxed" mode we just filter out some really
obvious, dangerous stuff. i.e. strict is whitelisting what is OK, but
"relaxed" is blacklisting what is really not OK.
The idea is that we use strict mode whenver we allocate a new user
(i.e. in sysusers.d or homed), while "relaxed" mode is when we process
users registered elsewhere, (i.e. userdb, logind, …)
The requirements on user name validity vary wildly. SSSD thinks its fine
to embedd "@" for example, while the suggested NAME_REGEX field on
Debian does not even allow uppercase chars…
This effectively liberaralizes a lot what we expect from usernames.
The code that warns about questionnable user names is now optional and
only used at places such as unit file parsing, so that it doesn't show
up on every userdb query, but only when processing configuration files
that know better.
Fixes: #15149#15090
We're operating on known paths in root-owned directories here, so the detour
through toctou-safe methods that require /proc to be mounted is not necessary.
Should fix https://bugzilla.redhat.com/show_bug.cgi?id=1807768.
See https://bugzilla.redhat.com/show_bug.cgi?id=1807768. It turns
out that sysusers cannot query if the group exists:
Failed to check if group dnsmasq already exists: No such process
...
Failed to check if group systemd-timesync already exists: No such process
When the same command is executed later, the issue does not occur. Not sure why
the behaviour in the initial transaction is different. But let's accept all
errors that the man pages list. We check if the user/group exists before creating
anyway, so this seems pretty safe.
This extends the "uid:gid" syntax for "u" lines so that a group
name can be given instead of a GID. This requires that the group
is either queued for creation by sysusers, or it is already defined
on the system.
Closes#14340
This reverts the gist of commit 636e72bce6.
The comment and the tiny cleanup are left alone.
We shouldn't lock the accounts because people actually need to use them, and
if they are locked, various tools will refuse.
See https://github.com/systemd/systemd/pull/13277#issuecomment-529964578
and follow-up comments.
Previously, we'd only set the shell to /usr/bin/nologin and lock the
password for system users. Let's go one step further and also lock the
whole account.
This is a paranoid safety precaution, since neither disabling the shell
like this nor disabling the password is sufficient to lock an account,
since remote shell tools generally allow passing different shells, and
logins into ftp or similar protocols don't know the shell concept anyway.
Moreover, in times of ssh authentication by password is just one
option of authentication among many.
Takes inspiration from the recommendations in usermod(8)'s -L switch:
"Note: if you wish to lock the account (not only access with a
password), you should also set the EXPIRE_DATE to 1."
Some distros install nologin as /usr/sbin/nologin, others as
/sbin/nologin.
Since we can't really on merged-usr everywhere (where the path wouldn't
matter), make the path build time configurable via -Dnologin-path=.
Closes#13028
Whenever I see EXTRACT_QUOTES, I'm always confused whether it means to
leave the quotes in or to take them out. Let's say "unquote", like we
say "cunescape".
Let's be helpful to static analyzers which care about whether we
knowingly ignore return values. We do in these cases, since they are
usually part of error paths.
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.
Ideally, coccinelle would strip unnecessary braces too. But I do not see any
option in coccinelle for this, so instead, I edited the patch text using
search&replace to remove the braces. Unfortunately this is not fully automatic,
in particular it didn't deal well with if-else-if-else blocks and ifdefs, so
there is an increased likelikehood be some bugs in such spots.
I also removed part of the patch that coccinelle generated for udev, where we
returns -1 for failure. This should be fixed independently.
Pretty much everything uses just the first argument, and this doesn't make this
common pattern more complicated, but makes it simpler to pass multiple options.
This is a bit like the info link in most of GNU's --help texts, but we
don't do info but man pages, and we make them properly clickable on
terminal supporting that, because awesome.
I think it's generally advisable to link up our (brief) --help texts and
our (more comprehensive) man pages a bit, so this should be an easy and
straight-forward way to do it.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
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.
The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
This corresponds nicely with the specifiers we already pass for
/var/lib, /var/cache, /run and so on.
This is particular useful to update the test-path service files to
operate without guessable files, thus allowing multiple parallel
test-path invocations to pass without issues (the idea is to set $TMPDIR
early on in the test to some private directory, and then only use the
new %T or %V specifier to refer to it).
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
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.
Commit 563dc6f8e2 added support for
/etc/{passwd,group} only but since nsswitch.conf(5) appears to document the NIS
entries also for shadow, let's support this case too.
The NIS-catchall entry switches from files to NIS lookup and never goes back,
so it must be the last entry in /etc/passwd (the other +/-{user,@netgroup}
entries don't have to be).
That's how the nss_compat mode for /etc/passwd (and /etc/group) traditionally
works.
It's age-old historic behaviour that the NIS entry must be the last one. It
doesn't seem to be specified somewhere, but it worked like this since very
early SunOS when NIS was first included.
Fixes: #8467
This PR implements the first part of RFE #8046. I.e. this allows to
write:
```
u username -:300
```
Where the uid is chosen automatically but the gid is fixed.
When used in a package installation script, we want to invoke systemd-sysusers
before that package is installed (so it can contain files owned by the newly
created user), so the configuration to use is specified on the command
line. This should be a copy of the configuration that will be installed as
/usr/lib/sysusers.d/package.conf. We still want to obey any overrides in
/etc/sysusers.d or /run/sysusers.d in the usual fashion. Otherwise, we'd get a
different result when systemd-sysusers is run with a copy of the new config on
the command line and when systemd-sysusers is run at boot after package
instalation. In the second case any files in /etc or /run have higher priority,
so the same should happen when the configuration is given on the command line.
More generally, we want the behaviour in this special case to be as close to
the case where the file is finally on disk as possible, so we have to read all
configuration files, since they all might contain overrides and additional
configuration that matters. Even files that have lower priority might specify
additional groups for the user we are creating. Thus, we need to read all
configuration, but insert our new configuration somewhere with the right
priority.
If --target=/path/to/file.conf is given on the command line, we gather the list
of files, and pretend that the command-line config is read from
/path/to/file.conf (doesn't matter if the file on disk actually exists or
not). All package scripts should use this option to obtain consistent and
idempotent behaviour.
The corner case when --target= is specified and there are no positional
arguments is disallowed.
v1:
- version with --config-name=
v2:
- disallow --config-name= and no positional args
v3:
- remove --config-name=
v4:
- add --target= and rework the code completely
v5:
- fix argcounting bug and add example in man page
v6:
- rename --target to --replace
If the configuration is included in a script, this is more convient.
I thought it would be possible to use this for rpm scriptlets with
'%pre -p systemd-sysuser "..."', but apparently there is no way to pass
arguments to the executable ($1 is used for the package installation count).
But this functionality seems generally useful, e.g. for testing and one-off
scripts, so let's keep it.
There's a slight change in behaviour when files are given on the command line:
if we cannot parse them, error out instead of ignoring the failure. When trying
to parse all configuration files, we don't want to fail even if some config
files are broken, but when parsing a list of items specified explicitly, we
should.
v2:
- rename --direct to --inline
This is the first error message when running unprivileged, and the message is
unspecific, so let's at least add some logging at debug level to make this less
confusing.
