The three functions for reading cwd, exe and root symlinks of processes
already share a common core: get_process_link_contents(). Let's refactor
that a bit, and move formatting of the /proc/self/ path into this helper
function instead of doing that in the caller, thus sharing more code.
While we are at it, make the return parameters optional, in case the
information if the links are readable is interesting, but the contents
is not. (This also means safe_getcwd() and readlinkat_malloc() are
updated to make the return parameter optional, as these are called by
the relevant three functions)
Containers generally have a smaller UID range assigned than host
systems. Let's visualize this in the user/group tables. We insert
markers for unavailable regions. This way display is identical to status
quo ante on host systems, but in containers unavailable ranges will be
shown as that.
And while we are at it, also hide well-known UID ranges when they are
outside of userns uid_map range. This is mostly about the "container"
range. It's pointless showing the cotnainer range (i.e. a range UID >
65535) if that range isn#t available in the container anyway.
This will taint systemd if invoked in containers that do not have the
full 16bit range of UIDs defined.
we pretty much need uid root…nobody to be defined for a variety of
purposes, hence let's add this taint flag. Of course taints are
graceful, but it at least communicates the mess in some way...
The former checks if one UID is inside the uid range set. The latter
checks if a full UID range is inside the uid range set. The former is
hence a special case of the latter.
I regularly run my tests also as root, since some of the tested code
uses privileged APIs. The test-resolved-stream so far tried to run its
tests in a user/network namespace if that can be allocated. This caused
the tests to fail on my system where once the user namespace is opened
access to the build tree in my $HOME is prohibited (due to restricted
access modes on my home dir). Let's add a check for that: before
actually isolating the test in a user/network namespace, let's see if
that would make it impossible for us to access the build tree (which we
need to do load the TLS certificates the test requires).
This should make the test pass when run as root from a build tree with
restrictive access mode.
We usually open() device node obtained by sd_device_get_devname().
However, the device node corresponds to the sd-device object may be
already removed, and another device node with the same path may be
created, hence an unexpected device may be opened.
The sd_device_open() opens device node, and checks the devnum and
diskseq of opened devnum, to avoid the above possibility.
Prompted by https://github.com/systemd/systemd/issues/22906#issuecomment-1082736443.
"Link-local" and "link local" are used throughout man pages and program
output, with the former used far more than the latter. This commit makes
it consistent throughout the project.
Accessing the various arguments always through argv[] is nasty, since
it's not obvious what we are talking about here. Let's give things nice
names.
We did the same in cryptsetup a while back.
Let's upgrade log levels of some noteworthy messages from LOG_DEBUG to
LOG_NOTICE. These messages contain information that previous log
messages in the error path didn't say, namely that we'll now fall back
to traditional unlocking.
Note that this leaves similar log messages for cases where
TPM2/PKCS#11/FIDO2 support is disabled at build at LOG_DEBUG, since in
that case nothing really failed, we just systematically can't do
TPM2/PKCS#11/FIDO2 and hence it is pointless and not actionable for
users to do anything about it...
