Setting the flags means we won#t try to read the data from /etc/shadow
when reading a user record, thus slightly making conversion quicker and
reducing the chance of generating MAC faults, because we needlessly
access a privileged resource. Previously, passing the flag didn't
matter, when converting our JSON records to NSS since the flag only had
an effect on whether to use NSS getspnam() and related calls or not. But
given that we turn off NSS anyway as backend for this conversion (since
we want to avoid NSS loops, where we turn NSS data to our JSON user
records, and then to NSS forever and ever) it was unnecessary to pass
it.
This changed in one of the previous commits however, where we added
support for reading user definitions from drop-in files, with separate
drop-in files for the shadow data.
This adds a two new values to --private-users-ownership=: "map" and
"auto".
"map" exposes the kernel 5.12 idmap feature pretty much 1:1. It fails if
the kernel or used file system doesn't support ID mapping.
"auto" is a bit smarter: if we can make ID mapping work, we'll use it,
otherwise revert back to classic chown()ing. We'll also use chown()ing
if we detect that an image is already ID shifted, both to increase
compatibility with the status quo ante, and to simplify our codepaths,
since the mappings become a lot simpler if we only have to map from zero
to something else, instead of from anything to anything else.
The short -U switch, and --private-users=pick will now imply
--private-users-ownership=auto instead of
--private-users-ownership=chown, since the new logic should be the much
better choice.
This makes use of the new kernel 5.12 APIs to add an idmap to a mount
point. It does so by cloning the mountpoint, changing it, and then
unmounting the old mountpoint, replacing it later with the new one.
This replaces --private-user-chown by an enum value
--private-user-ownership=off|chown. Changes otherwise very little.
This is mostly preparation for a follow-up commit adding a new "map"
mode, using kernel 5.12 UID mapping mounts.
Note that this does alter codeflow a bit: the new enum already knows
three different values instead of the old true/false pair. Besides "off"
and "chown" it knows -EINVAL, i.e. whenever the value wsn't set
explicitly. This value is changed to "off" or "chown" before use, thus
retaining compat to the status quo before, except it won't override
explicit configuration anymore. Thus, if you explicitly request
--private-user=pick you can now combine it wiht an explicit
--private-user-ownership=off if you like, which will give you a
container that runs under its own UID set, but the files will be owned
by the original image. Makes not much sense besids maybe debugging, but
if requested explicitly I think it's OK to implement.
userns identity 1:1 mapping is a pretty useful concept since it isolates
capability sets between containers and hosts, even if it doesn't map
any uid ranges. Let's support it with an explicit concept.
(Note that this is identical to --private-users=0:65536 (which in turn
is identical to --private-users=0), but I think it makes to emphasize
this concept as a high-level one that makes sense to support.)
So far we basically had two ways to iterate through NSS records: one via
the varlink IPC and one via the userdb.[ch] infra, with slightly
different implementations.
Let's clean this up, and always use userdb.[ch] also when resolving via
userdbd. The different codepaths for the NameServiceSwitch and the
Multiplexer varlink service now differ only in the different flags
passed to the userdb lookup.
Behaviour shouldn't change by this. This is mostly refactoring, reducing
redundant codepaths.
Let's use "exclude" for flags that really exclude records from our
lookup. Let's use "avoid" referring to concepts that when flag is set
we'll not use but we have a fallback path for that should yield the same
result. Let' use "suppress" for suppressing partial info, even if we
return the record otherwise.
So far we used "avoid" for all these cases, which was confusing.
Whiel we are at it, let's reassign the bits a bit, leaving some space
for bits follow-up commits are going to add.
This fixes the following error:
```
In file included from ../src/basic/af-list.h:6,
from ../src/basic/af-list.c:7:
../src/basic/string-util.h: In function 'char_is_cc':
../src/basic/string-util.h:133:19: error: comparison is always true due to limited range of data type [-Werror=type-limits]
133 | return (p >= 0 && p < ' ') || p == 127;
| ^~
cc1: all warnings being treated as errors
```
Fixes#19543.
userdbd listens on "two" sockets, that are actually the same: one is a
real AF_UNIX socket in the fs, and the other is a symlink to it.
So far, when userdbd was started from the command line it would make one
a symlink and the other a real socket, but when invoked via unit files
they'd be swapped, i.e. the other would be a symlink and the one a real
socket.
Let's bring this in line.
Since the "io.systemd.Multiplexer" is our main interface, let's make it
the one exposed as socket, and then make "io.systemd.NameServiceSwitch"
a symlink to it. Or in other words, let's adjust the C code to match the
unit file.
When we are queried for membership lists on a system that has exactly
zero, then we'll return ESRCH immediately instead of at EOF. Which is
OK, but we need to handle this in various places, and not get confused
by it.
It's not going to be efficient if called in inner loops, but it's oh so
handy, and we have some code that does this:
asprintf(&p, "%s…", b, …);
free(b);
b = TAKE_PTR(p);
which can now be replaced by the quicker and easier to read:
strextendf(&p, "…", …);
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.
This fixes an issue introduced by the commit 954c77c251.
For some reasons, setting default ACL on $TESTDIR makes TEST-29-PORTABLE
fail. Let's drop the default ACL, and set ACL on saved results instead.
Fixes#19519.
D330-10IGM has been added due the fact that 81H3 and 81MD product name belongs to the same product version. So the fact is that now that we know 81MD has the same transformation matrix that the 81H3 we can just use the product version and get rid the product name.
Signed-off-by: David Santamaría Rogado <howl.nsp@gmail.com>
Lennart Poettering
Yu Watanabe
Yegor Alexeyev
Marco Antonio Mauro
Frantisek Sumsal
Zbigniew Jędrzejewski-Szmek
Mike Kazantsev
Luca Boccassi
Dimitri John Ledkov
Mark Wielaard
howl
Phaedrus Leeds