This PR only sets the default to "relaxed" - I can change the default
to "tofu" if desired. But for that we will also need to update the NEWS
file to ensure everyone is aware of this new default.
---
This PR adds a new `systemd.credentials-boot=` kernel
commandline that allows to control if credentials with
a `null` key are accepted.
The possible options are:
* strict: always insist on tpm encryption
* tofu: allow null encryption in firstboot mode and when no tpm is
available
* relaxed: allow null encryption when sb is off, or no tpm is available
* off: allow null encryption always
The default is `relaxed` which is exactly the behavior we had before.
This replaces the initial idea of using plaintext credentials
at firstboot (thanks to Lennart for this nicer and simpler design).
---
With that we can drop `- firstboot: optionally accept credentials at
firstboot without authentication` from TODO.md
Extend ConditionCPUFeature to support architecture prefixes in feature names.
The goal is avoiding ambiguities on mixed-arch fleets, where CPU feature names
may potentially conflict.
With this patch, ConditionCPUFeature=arm64.bti is now equivalent to
ConditionCPUFeature=bti on arm64 systems.
Signed-off-by: Emanuele Rocca <emanuele.rocca@arm.com>
Even though systemd-networkd and systemd-udevd do not support
ConditionSecurity= in .network, .netdev, and .link files, the unified
condition_test() function maintained a function pointer table that
unconditionally referenced condition_test_security(). Consequently,
linker garbage collection (--gc-sections) could not drop the security
test code, inadvertently pulling in dlopen dependencies and ELF notes
for apparmor, audit, and tpm2 libraries into these binaries.
To resolve this, introduce condition_test_net() and condition_test_list_net(),
which utilize a trimmed-down function pointer table that excludes
security-related condition evaluators.
By migrating networkd and udevd to these new network-specific variants,
the reference to condition_test_security() is completely severed in
their dependency chains. This allows the compiler and linker to
successfully garbage-collect the unused security logic and safely drops
the unnecessary dlopen notes from those binaries.
This commit tweaks the in_first_boot() code to make it
a proper shared helper. It tweaks the comments about the
caching policy. This is important because while this is
simialr to `in_initrd()` there is a suble difference:
we never cache the result of access() because other parts
of systemd will use this file to signal if anything about
firstboot changes.
This also tweaks it to return an int instead of a bool.
So any error is returned as -errno. This allows other
parts of systemd (like the random-seed) that need to make
decisions about "unknown" first-boot state.
This also means that the consumers need to get updated
and we can now also use the new helper in random-seed-tool.c
and have only a single helper to check for first-boot.
This commit adds a new `systemd.credentials_boot_policy=` kernel
commandline that allows to control if credentials with
a `null` key are accepted.
The possible options are:
* strict: always insist on tpm encryption
* tofu: allow null encryption in firstboot mode and when no tpm is available
* relaxed: allow null encryption when sb is off, or no tpm is available
* off: allow null encryption always
The default is currently `relaxed` which is the same behavior
as before.
This replaces the initial idea of using plaintext credentials
at firstboot (thanks to Lennart for this nicer and simpler design).
Note that this also moves `in_first_boot()` to `basic/initrd-util`
which is a better fit now.
get_user_creds would use getpwnam() and then returns strings pointing
into the static buffer. This seems very iffy. Let's duplicate the
strings properly
There are some unnecessary() if() checks for variables
that are already guarded by assert()s. Drop those.
Thanks to keszybz for clarifying the direction of this commit.
So far we always conditioned our TPM magic on the UKI having detected
TPM support in the firmware. This is a bit limiting when we want to
support a software TPM that is not visible to the firmware. Hence let's
split this up, and add a separate control that can be set via the kernel
command line. However, as before, let's by default inherit the firmare
TPM discovery state into it, to retain the current behaviour unless
overriden.
With this in place, boot with "systemd.tpm2_measured_os=1
systemd.tpm2_software_fallback=1" on the kernel cmdline to get the swtpm
fallback and then a measured OS based on it.
We have dropped cgroup v1 support in v258. Let's drop legacy code.
Then, we can drop 'controller' argument from cg_pid_get_path() and
cg_pidref_get_path().
bus_append_unit_property() and associated functions accept a long list of
properties. But the specific names are only available through code. But it is
useful to be able to know the specific list of properties that is supported, in
particular for shell completions. Thus, add a way to list the properties that
are supported by the code.
In the future we could also turn this into a test for the documentation. For
various reasons, the list of properties listed in the docs is a partially
overlapping set. E.g. for service type, the pull request
https://github.com/systemd/systemd/pull/37661 creates a list with 212 entries,
and this code generates 7 entries less and 184 more. I didn't check all the
differences, but in the few cases I did, the list generated here was actually
correctly supported by 'systemd-run -p'.
A smoke test is added.
git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.
In one of the next commits we'd like to introduce a concept of
optionally hashing the hostname from the machine ID. For that we we need
to optionally back gethostname_full() by code involving sd-id128, hence
let's move it from src/basic/ to src/shared/, since only there we are
allowed to use our public APIs.
Sometimes it's interesting to condition units not just on the
installation but on the physical device. Let's make ConditionHost=
useful for that kind of checks, and while we are at it, also allow it to
be used for condition checks on the boot id.
Overloading like this is safe, since UUIDs are globally unique after
all, and hence there should be no conflicts between the namespace of
boot ids, machine ids and product ids.
Finally, relax rules on uuid checking: if the specified string parses
as uuid or id, also check it against the hostname, for setups where
people name hosts after uuids. I wouldn't know why anyone would do that,
but also, why not? shouldn'rt hurt allowing them and should not create
ambiguity conflicts.
'ConditionOSRelease=|ID_LIKE$=*rhel*' results in a segfault.
The key 'ID_LIKE' is not present in Fedora's os-release file.
I think the most reasonable behaviour is to treat missing keys as empty.
This matches the "shell-like" sprit, since in a shell empty keys would
by default be treated as empty too. Thus, "ID_LIKE=" would match, if
ID_LIKE is not present in the file, and ID_LIKE=!$foo" would also match.
The other option would be to make those matches fail, but I think that'd
make the feature harder to use, esp. with negative matches.
Documentation is updated to clarify the new behaviour.
https://bugzilla.redhat.com/show_bug.cgi?id=2345544
This generalizes and modernizes the code to acquire set of local caps,
based on the code for this in the condition logic. Uses PidRef, and
acquires the full quintuplet of caps.
This can be considered preparation to one day maybe build without
libcap.
This introduces a new unit condition check: that matches if a specific
kmod module is allowed. This should be generally useful, but there's one
usecase in particular: we can optimize modprobe@.service with this and
avoid forking out a bunch of modprobe requests during boot for the same
kmods.
Checking if a kernel module is loaded is more complicated than just
checking if /sys/module/$MODULE/ exists, since kernel modules typically
take a while to initialize and we must check that this is complete (by
checking if the sysfs attr "initstate" is "live").
cpu.pressure 'full' is undefined for system-wide checks since 5.13 but still reported with values set to 0 for backwards compatibility. Made changes to reflect this for system-wide checks so that the conditional comparison is not made against the 0 value and instead fall back to 'some'.
https://www.kernel.org/doc/html/latest/accounting/psi.html
- drop unnecessary SYNTHETIC_ERRNO() when the logger does not propagate
error code,
- drop unnecessary '%m' in error message when the error code is
specified with SYNTHETIC_ERRNO(),
- add missing full stop at the end of log message,
- use RET_GATHER(),
- add missing ", ignoring.",
- upeercase the first letter, etc., etc...
Most of our kernel cmdline options use underscores as word separators in
kernel cmdline options, but there were some exceptions. Let's fix those,
and also use underscores.
Since our /proc/cmdline parsers don't distinguish between the two
characters anyway this should not break anything, but makes sure our own
codebase (and in particular docs and log messages) are internally
consistent.
We had both uid-range.h and uid-alloc-range.h. The latter now contains helpers
like {uid,gid}_is_{system,dynamic,container}(), uid_for_system_journal(), so
the existing name is outdated. I think the uid-range.[ch] should stay separate
because it has a bunch of helpers for parsing and printing of uid ranges. So
let's rename as in $subject to better reflect the contents of the file and make
the two sets of files harder to confuse.
I figure these messages are rather unnecessary, so let the user quiet
them with the existing --quiet flag if desired. Makes systemd-analyze
condition a little more ergonomic in scripts.
No code change, just some splitting out of the relevant code from
udev-util.[ch].
This makes sense on its own, but is also prepartion to move the code
that checks for low battery state into battery-util.[ch], too.
Before 7cd43e34c5, it was possible to use
SYSTEMD_PROC_CMDLINE=systemd.condition-first-boot to override autodetection.
But now this doesn't work anymore, and it's useful to be able to do that for
testing.