kernel 5.6 added support for a new flag for getrandom(): GRND_INSECURE.
If we set it we can get some random data out of the kernel random pool,
even if it is not yet initializated. This is great for us to initialize
hash table seeds and such, where it is OK if they are crap initially. We
used RDRAND for these cases so far, but RDRAND is only available on
newer CPUs and some archs. Let's now use GRND_INSECURE for these cases
as well, which means we won't needlessly delay boot anymore even on
archs/CPUs that do not have RDRAND.
Of course we never set this flag when generating crypto keys or uuids.
Which makes it different from RDRAND for us (and is the reason I think
we should keep explicit RDRAND support in): RDRAND we don't trust enough
for crypto keys. But we do trust it enough for UUIDs.
Let's make the logic a bit smarter: if we detect that /home is
encrypted, let's avoid double encryption and prefer plain
directory/subvolumes instead of our regular luks images.
Also, allow configuration go storage/file system via an env var passed
to homework. In a later commit, let's then change homed to initialize
that env var from a config file setting, when invoking homework.
Make use of the new user_record_build_image_path() helper the previous
commit added to share some code.
Also, let's make sure we update all parsed-out fields with the new data
from the binding, so that the parsed-out fields are definitely
up-to-date.
We should return 0 only if current freezer state, as reported by the
kernel, is already the desired state. Otherwise, we would dispatch
return dbus message prematurely in bus_unit_method_freezer_generic().
Thanks to Frantisek Sumsal for reporting the issue.
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.
Ideally, assert_cc() would be used for this, so that it is not possible to even
compile systemd with something like '-Dfallback-hostname=.foo'. But to do a
proper check we need to call hostname_is_valid(), and we cannot depend on being
able to run code (e.g. during cross-compilation). So let's do a very superficial
check in meson, and a proper on in test-util.
This new helper checks whether the specified locale is installed. It's
distinct from locale_is_valid() which just superficially checks if a
string looks like something that could be a valid locale.
Heavily inspired by @jsynacek's #13964.
Replaces: #13964
There are two libc APIs for accessing the user database: NSS/getpwuid(),
and fgetpwent(). if we run in --root= mode (i.e. "offline" mode), let's
use the latter. Otherwise the former. This means tmpfiles can use the
database included in the root environment for chowning, which is a lot
more appropriate.
Fixes: #14806
We make this entirely independent of the regular discard field, i.e. the
one that controls discard behaviour when the home directory is online.
Not all combinations make a ridiculous amount of sense, but most do.
Specifically:
online-discard = yes, offline-discard = yes
→ Discard when activating explicitly, and during runtime using
the "discard" mount option, and discard explicitly when logging
out again.
online-discard = no, offline-discard = yes
→ The new default: when logging in allocate the full backing
store, and use no discard while active. When loging out discard
everything. This provides nice behaviour: we take minimal storage
when offline but provide allocation guarantees while online.
online-discard = no, offline-discard = no
→ Never, ever discard, always operate with fully allocated
backing store. The extra safe mode.
Let's make debugging a bit easier: when invoking homed from the build
tree it's now possible to make sure homed invokes the build tree's
homework binary by setting an env var.