This macro emits an SD_ELF_NOTE_DLOPEN note so that calling sites,
and not just libsystemd-shared, get the ELF stamped with the notes
documenting the dependency. Currently most of the dlopen notes end
up in libsystemd-shared, and executables have no way to document
the optional dependencies they need. With this new macro, this
issue can be fixed.
Co-developed-by: Claude Opus 4.8 <noreply@anthropic.com>
Each dlopen_*() wrapper kept its dl handle as a file-scope
'static void *xxx_dl = NULL;' even though only the wrapper itself
ever referenced it. Move each one inside the corresponding function
so its scope matches its actual use, leaving the rest of each
translation unit free of the unused file-scope name.
In pcre2-util.c the assert(pcre2_dl) in pattern_matches_and_log()
becomes assert(sym_pcre2_match), which carries the same invariant
(pattern_compile_and_log() ran dlopen_pcre2()).
This avoids having to subpackage the tokens separately. If they link directly
against libcryptsetup, package manager will automatically add a dependency on
libcryptsetup to the package containing the tokens. With this change, the tokens
can ship in the main systemd package without necessarily pulling in libcryptsetup.
It also makes things more consistent. Once we also do the same for pam, any direct
linking will be limited to just libc, which for example simplifies writing tests for
ensuring we don't link unnecessarily as we don't have to add exceptions for the
cryptsetup tokens.
This actually drops the dependency on cryptsetup-libs for the fedora/centos/opensuse
systemd-udev package so install it explicitly in the initrd now to keep the tests
working.
For libc syscall wrappers (pidfd_open, fsopen, openat2, etc.) we previously
gated the calls behind build-time HAVE_* checks. Replace these with shim
functions in src/libc/ that fall back to the raw syscall at runtime when the
loaded glibc lacks the symbol. The infrastructure lives in src/libc/libc-shim.h:
DEFINE_SYSCALL_SHIM falls back to a direct syscall, DEFINE_LIBC_SHIM returns
ENOSYS (for posix_spawn-family helpers that have no corresponding syscall), and
DEFINE_LIBC_ERRNO_SHIM sets errno=ENOSYS and returns -1 (for read/write-style
helpers). The weak reference to the libc symbol is bound via __asm__(\"name\")
rename so the bare libc identifier never appears as a C token — this avoids
both #undef boilerplate against override-header redirects and the resulting
-Wredundant-decls warning. Drop the corresponding cc.has_function() loop from
meson.build.
For optional libraries (libcryptsetup, libdw, libarchive), drop the per-symbol
HAVE_* checks. Always declare the prototypes, suppressing the redundant-decl
warnings via DISABLE_WARNING_REDUNDANT_DECLS and NOLINT, and resolve the symbols
after the main dlopen via a new DLSYM_OPTIONAL() helper that only assigns on
success. libcryptsetup's crypt_set_keyring_to_link / crypt_token_set_external_path
and libarchive's *_is_set wrappers use fallback functions as their pointer
initializers (returning -ENOSYS and 0 respectively), so call sites can invoke
the symbol unconditionally and just check for -ENOSYS where the \"not supported\"
distinction matters.
The same shim treatment applies to pidfd_spawn / posix_spawnattr_setcgroup_np
(src/libc/spawn.c) and epoll_pwait2 (src/libc/epoll.c), with corresponding
override headers in src/include/override/spawn.h and
src/include/override/sys/epoll.h. posix_spawn_wrapper() in process-util.c and
epoll_wait_usec() in sd-event.c now detect ENOSYS in the return value instead
of checking the function pointer, falling back to plain posix_spawn() and
epoll_wait() respectively. coredump-config and coredump-submit get a
dlopen_dw_has_dwfl_set_sysroot() helper. The kexec arch gate now uses
defined(__NR_kexec_file_load) directly; pidfd.h uses __has_include_next() to
decide whether to pull in glibc's header.
This lets binaries built against newer glibc / libcryptsetup / libdw /
libarchive headers still load and run on older targets where these symbols are
absent.
cryptsetup_set_minimal_pbkdf(), cryptsetup_get_token_as_json() and
cryptsetup_add_token_json() each take a struct crypt_device *cd, which
can only be obtained by first calling sym_crypt_init*() — and that
already requires dlopen_cryptsetup() to have succeeded. The internal
calls here were only implicitly re-loading a library the caller is
guaranteed to have already loaded.
Convert systemd-cryptsetup, systemd-cryptenroll, systemd-veritysetup
and systemd-integritysetup to go through the existing dlopen wrapper
for libcryptsetup instead of linking the library directly. Each binary
calls dlopen_cryptsetup() at the start of its run() and uses the sym_*
variants for every libcryptsetup entry point.
Extend cryptsetup-util.{h,c} to cover the libcryptsetup symbols that
these binaries use and that the wrapper was missing:
crypt_activate_by_token_pin, crypt_deactivate, crypt_init_data_device,
crypt_keyslot_status, crypt_set_keyring_to_link (conditional on
HAVE_CRYPT_SET_KEYRING_TO_LINK), crypt_status and
crypt_token_external_path.
With no direct callers of crypt_free() left, drop the non-sym
crypt_freep cleanup variant and rename sym_crypt_freep back to
crypt_freep via DEFINE_TRIVIAL_CLEANUP_FUNC_FULL_RENAME, matching the
naming convention used by other dlopen wrappers (acl_freep,
xkb_context_unrefp, ...). Update the remaining users in src/shared,
src/repart, src/home and src/growfs to the new name.
The four affected meson targets switch from libcryptsetup to
libcryptsetup_cflags so they no longer record a DT_NEEDED entry for
libcryptsetup.so.12.
Every dlopen_xxx() helper now takes an int log_level argument. It is
passed through to dlopen_many_sym_or_warn() (which in turn propagates it
to dlopen_verbose() for the library-not-installed case), and is used by
the fallback stub when support for the library is not compiled in to
emit a "<lib> support is not compiled in." message at the caller's level.
Callers pass LOG_DEBUG when gracefully degrading, or a higher level when
the failure should surface, and no longer need to log redundantly at the
call site.
As part of this, dlopen_bpf_full() (which already took a log_level) is
merged into dlopen_bpf() rather than keeping both.
The static inline fallbacks used to live in the headers, which required
pulling log.h in from every header that declared a dlopen_xxx(). Move
them into the .c files instead: the declaration is always outside the
#if HAVE_XXX block, the impl sits outside the outer #if HAVE_XXX wrap
with its own internal #if HAVE_XXX/#else/#endif, and apparmor-util.c,
idn-util.c, libmount-util.c and pam-util.c are now always compiled so
they can host their stubs.
The updated parsing_hacks.h file uncovered a bunch of extra
things that the check-pointer-deref coccinelle script flags.
This commit fixes them to make the tree check-pointer-deref clean.
AllowDiscards= will set allow-discards in the persistent flags which will make
activating the device automatically activate with that option. This is
useful for devices discovered through gpt-auto-generator without
needing to use some kernel command line to set the option.
Switch all internal callers from the private ELF_NOTE_DLOPEN() macro to
the new public SD_ELF_NOTE_DLOPEN() API from sd-dlopen.h, and remove
the now-redundant macro definitions from dlfcn-util.h.
Signed-off-by: Christian Brauner <brauner@kernel.org>
The expected hash (SHA265 HMAC signature) uses the exact same algorithm which
is used to calculate sha256 PCR bank digest when 'tpm2-measure-pcr=' is used.
Major distributions already have cryptsetup newer than 2.4.0.
Let's bump the minimal required version.
Note, cryptsetup 2.4.0 was released on 2021-08-18.
See also #38608.
LUKS2 supports built-in integrity checking which may come very handy to
mitigate partial rollback attacks on the storage when only some specific
parts are restored to some old encrypted state. Specific use-cases like
Confidential VMs may want to mandate the usage of feature e.g. on the root
volume. Introduce "encryptedwithintegrity" image policy to support that.
Note, due to the current libcryptsetup limitations, checking whether the
feature is enabled or not for the 'file' case (e.g. DDI image as a raw file)
requires setting up a loop device. To avoid that and keep dissect fully
functional when working unpriviliged, implement a minimal custom LUKS header
parser.
Authenticated disk encryption is experimentally supported by cryptsetup since
v2.0.0 and allows for automatic dm-integrity setup for LUKS devices. Add
support for the mode to systemd-repart. Currently, the option can only be used
in 'online' mode as libcryptsetup does not support creating integrity data
without the use of in-kernel dm-integrity infrastructure.
Integrity=/IntegrityAlgorithm= are added in the anticipation of other integrity
protection options, e.g. enabling dm-integrity for a plain unencrypted
partition.
Every other log in this function is debug level, so downgrade this too.
Otherwise compiling without libcryptsetup means sd-executor logs at
error level when starting any service, regardless of whether it is
needed or not.
Fixes https://github.com/systemd/systemd/issues/39968
Follow-up for efaf5a763d
The functions crypt_set_metadata_size() and friends are supported since
libcryptsetup-2.0.
This also merges checks for functions used for supporting libcryptsetup
plugins with others.
Moreover, check existence of one more function (crypt_logf) that is used in
libcryptsetup plugins.
Let's make use of libcryptsetup's new crypt_token_set_external_path()
API in place of the interposition stuff we have been doing before. Let's
kill it entirely, given that this was a developer feature only anyway
(and guarded by an appropriate ifdef).
Fixes: #30098
This is preparation for making our Varlink API a public API. Since our
Varlink API is built on top of our JSON API we need to make that public
first (it's a nice API, but JSON APIs there are already enough, this is
purely about the Varlink angle).
I made most of the json.h APIs public, and just placed them in
sd-json.h. Sometimes I wasn't so sure however, since the underlying data
structures would have to be made public too. If in doubt I didn#t risk
it, and moved the relevant API to src/libsystemd/sd-json/json-util.h
instead (without any sd_* symbol prefixes).
This is mostly a giant search/replace patch.
When looking at how dlopen for various libs is implemented, I found that the
macros hide too much. I find it much easier to see what is going on if 'extern'
and '= NULL' are written explicitly. After all, we don't hide those for other
definitions, e.g. our style guide says that static variables should be
initialized with '= NULL'. With that change, it's much more obvious what is
a variable declaration and what is a variable initialization.
Use 'recommended' priority for the default compression library, to
indicate that it should be prioritized over the other ones, as it
will be used to compress journals/core files.
Also use 'recommended' for kmod, as systems will likely fail to boot
if it's missing from the initrd.
Use 'suggested' for everything else.
There is one dlopen'ed TPM library that has the name generated
at runtime (depending on the driver), so that cannot be added, as it
needs to be known at build time.
Also when we support multiple ABI versions list them all, as for the
same reason we cannot know which one will be used at build time.
$ dlopen-notes.py build/libsystemd.so.0.39.0 build/src/shared/libsystemd-shared-256.so
libarchive.so.13 suggested
libbpf.so.0 suggested
libbpf.so.1 suggested
libcryptsetup.so.12 suggested
libdw.so.1 suggested
libelf.so.1 suggested
libfido2.so.1 suggested
libgcrypt.so.20 suggested
libidn2.so.0 suggested
libip4tc.so.2 suggested
libkmod.so.2 recommended
liblz4.so.1 suggested
liblzma.so.5 suggested
libp11-kit.so.0 suggested
libpcre2-8.so.0 suggested
libpwquality.so.1 suggested
libqrencode.so.3 suggested
libqrencode.so.4 suggested
libtss2-esys.so.0 suggested
libtss2-mu.so.0 suggested
libtss2-rc.so.0 suggested
libzstd.so.1 recommended
Co-authored-by: Luca Boccassi <bluca@debian.org>
This commit makes homework always upload the LUKS volume key into the
kernel keyring. This is different from previous behavior in three
notable ways:
- Previously, we'd only upload if auto-resize was on. In preparation for
upcoming changes, now we always upload
- Previously, we'd upload the user's actual password (or a password
obtained from a FIDO key or similar). Now, we upload the LUKS volume key
itself, to remove a layer of unnecessary indirection.
- Previously, Lock() wouldn't remove the key from the kernel keyring.
This, of course, defeats the purpose of Lock(), so now it removes the
key
This commit also allows the LUKS volume to be unlocked using the volume
key we obtained from the keyring.
We have these pretty macros, let's use them everywhere (so far we mostly
used them for newer additions only).
This PR is mostly an excercise in "perl -p -i -e", but there are some
special cases:
* idn-util.c exposes a function whose prototype in the official library
headers is marked with the "const" attribute, and this apparently does
not propagate along typeof() correctly and then
__builtin_types_compatible_p() fails later because it detects that
prototype and original function don't match in prototype.
* libbpf removed some symbols in newer versions, hence we need to define
some prototypes manually to still be able to build.
* libcryptsetup marked a symbol as deprecated we want to use (knowing it
is deprecated). By using the macros this is detected by the compiler.
We work around it via the usual warning off macros.
Note by using these macros we assume that all symbols are known during
build time. Which might not be the case. We might need to revert this
commit for some symbols if this trips up builds on older distros.
This code doesn't link when gcc+lld is used:
$ LDFLAGS=-fuse-ld=lld meson setup build-lld && ninja -C build-lld udevadm
...
ld.lld: error: src/shared/libsystemd-shared-255.a(libsystemd-shared-255.a.p/cryptsetup-util.c.o):
symbol crypt_token_external_path@@ has undefined version
collect2: error: ld returned 1 exit status
As a work-around, restrict it to developer mode.
Closes https://github.com/systemd/systemd/issues/30218.
I tried to get something similar upstream:
https://gitlab.com/cryptsetup/cryptsetup/-/issues/846
But no luck, it was suggested I use ELF interposition instead. Hence,
let's do so (but not via ugly LD_PRELOAD, but simply by overriding the
relevant symbol natively in our own code).
This makes debugging tokens a ton easier.
Make sure that the sym_xyz function pointers have the types that the
functions we'll assign them have.
And of course, this found a number of incompatibilities right-away, in
particular in the bpf hookup.
(Doing this will trigger deprecation warnings from libbpf. I simply
turned them off locally now, since we are well aware of what we are
doing in that regard.)
There's one return type fix (bool → int), that actually matters I think,
as it might have created an incompatibility on some archs.
Offline encryption can be done without mounting the luks device. For
now we still use loop devices to split out the partition we want to
write to but in a later commit we'll replace this with a regular file.
For offline encryption, we need to keep 2x the luks header size space
free at the end of the partition, so this means our encrypted partitions
will be 16M larger than before.
This splits out the JSON parser used by the systemd-cryptsetup code.
This is preparation for later work to reuse it in the tpm2 cryptsetup
token module, which currently uses a separate but very similar parser
for the same data.
No change in behaviour.
We warn when the operation fails, not when it succeeds. Hence this should be
"<do>_or_<handle failure>", not "<do>_and_<handle failure>". We *could* use
whatever convention we want, but rust and perl are rather consistent in using
the logical convention. We don't care about perl that much, but having a naming
convention inverted wrt. rust would be rather confusing.
Also, pretty much every implementation does similar steps, so add a nice
wrapper which combines opening of the library and loading of the symbols.
Also add missing sentinel attribute in dlopen_or_warn().
No need to benchmark pbkdf when asking for minimal values
anyway.
1000 iterations count is minimum for both LUKS1 and LUKS2
pbkdf2 keyslot parameters according to NIST SP 800-132, ch. 5.2.
Iterations count can not be lower than recommended minimum
when benchmark is disabled. The time_ms member is ignored with
benchmark disabled.
So far we only set the per-crypt_device log functions, but some
libcryptsetup calls we invoke without a crypt_device objects, and we
want those to redirect to our infra too.
Let's make libcryptsetup a dlopen() style dep for PID 1 (i.e. for
RootImage= and stuff), systemd-growfs and systemd-repart. (But leave to
be a regulra dep in systemd-cryptsetup, systemd-veritysetup and
systemd-homed since for them the libcryptsetup support is not auxiliary
but pretty much at the core of what they do.)
This should be useful for container images that want systemd in the
payload but don't care for the cryptsetup logic since dm-crypt and stuff
isn't available in containers anyway.
Fixes: #8249
"crypt-util.c" is such a generic name, let's avoid that, in particular
as libc's/libcrypt's crypt() function is so generically named too that
one might thing this is about that. Let's hence be more precise, and
make clear that this is about cryptsetup, and nothing else.
We already had cryptsetup-util.[ch] in src/cryptsetup/ doing keyfile
management. To avoid the needless confusion, let's rename that file to
cryptsetup-keyfile.[ch].
Luca Boccassi
Daan De Meyer
Michael Vogt
Valentin David
Christian Brauner
Vitaly Kuznetsov
Yu Watanabe
Daan De Meyer
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Mike Yuan
Adrian Vovk
Ondrej Kozina