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
The param was input/output, which is unexpected and confusing and
actually made most callers much more complicated than they needed to be.
The function was playing fast and loose with the return value. In some
cases it was returning a static string, which would be completely fine.
But in other case it was returning a pointer into the getgrgid static
buffer, i.e. that return value could be overwritten. AFAICT, this didn't
matter in any of the callers, but we shouldn't do that anyway.
So use a separate output param with an allocated string that the caller
is responsible for.
It turns out that all callers pass NULL (outside of tests) and zero for
flags. So the function _could_ be simplified. But get_user_creds is
called with all the params actually used, and I think having the the
functions so different wouldn't be nice. I first wrote a commit to
drop the unused params, but then I discarded it.
The error message in exec-invoke.c is fixed.
Drop the -fundamental suffix from src/fundamental/ headers in favor of names
that match their src/basic/ or src/shared/ counterparts (e.g.
macro-fundamental.h -> macro.h, assert-fundamental.h -> assert-util.h,
cleanup-fundamental.h -> cleanup-util.h). Rename src/basic/{btrfs,label}.{c,h}
to use the -util suffix to match the existing shared/btrfs-util and
shared/label-util siblings. Rename src/shared/mkdir-label.{c,h} to mkdir.{c,h}
and src/shared/tmpfile-util-label.{c,h} to tmpfile-util.{c,h} to match the
corresponding src/basic names.
This saves us from having to come up with separate names for files that do
the same thing across tiers, and it makes it easier to move stuff between
src/fundamental, src/basic and src/shared: consumers just #include "foo.h"
and pick up whichever tier their -I path resolves to first, so call sites
don't need to be updated when an API moves between layers.
Where a higher-tier wrapper exists (e.g. src/basic/macro.h wrapping
src/fundamental/macro.h), the wrapper uses an explicit "../fundamental/foo.h"
or "../basic/foo.h" relative include for the lower-tier header. We can't use
GCC's #include_next directive for this — when the wrapper is reachable both
via same-dir-as-source lookup and via -I (e.g. -Isrc/shared) for the
directory it lives in, #include_next advances by exactly one slot in libcpp's
internal directory chain and lands on the same physical directory it was
already in, never reaching the lower-tier sibling (see make_cpp_dir() in
gcc/libcpp/files.cc:1986).
To make sure the right headers are always picked up, the include directories
are reordered so that e.g. src/shared always takes priority over src/basic and
similar for the other directories.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
As per https://github.com/systemd/systemd/pull/41986#pullrequestreview-4281939586
This also corrects the list of unit types a bit:
1. this removes the mount/automount unit type from the list, since for these types
we do not allow aliases/renaming anyway.
2. this adds socket + swap units to the list, since they can change
name, and for both of them we actually do fork off processes hence
track resources.
Follow-up for: #41986
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.
After the update to 260-rc1 in Fedora Rawhide, we get a lot of messages like
this:
systemd[1]: systemd-resolved-monitor.socket:
Failed to create symlink /run/systemd/resolve/io.systemd.Resolve.Monitor →
/run/varlink/registry/io.systemd.Resolve.Monitor, ignoring: Permission denied
The actual issue will need to be fixed too, but let's fix the message first.
While at it, let's rename the variables to be meaningful.
Various socktops will fail if we run in a container, due to lack of
privs (for example SO_RECVFORCE as used by the journald sockets). That's
typically not a big issue. Hence downgrade the log level.
Follow-up for: f7df0eab8d
There is currently no way to figure out a rate limit was hit on a unit,
as the last result is stripped in order to keep reporting the first
result, which is useful in case of a watchdog failure, which is the
reason why it was changed as such.
But rate limiting is also an important information to provide to
users, so allow the Result property to reflect it when it
happens.
When a socket unit specifies SmackLabel=, the label was previously
not applied to the underlying Unix socket file or its file descriptor.
This change ensures that the SMACK label is applied both to the
socket path on the filesystem and to the opened socket FD.
$ sudo build/systemd-run --uid=asdf whoami
$ journalctl -e
(whoami)[1007784]: run-p1007782-i5200512.service: Failed to determine user credentials: No such process
(whoami)[1007784]: run-p1007782-i5200512.service: Failed at step USER spawning /usr/sbin/whoami: No such process
systemd[1]: run-p1007782-i5200512.service: Main process exited, code=exited, status=217/USER
systemd[1]: run-p1007782-i5200512.service: Failed with result 'exit-code'.
Now:
(whoami)[1013204]: run-p1013202-i5205932.service: Failed to determine credentials for user 'asdf': Unknown user
(whoami)[1013204]: run-p1013202-i5205932.service: Failed at step USER spawning /usr/sbin/whoami: Invalid argument
systemd[1]: run-p1013202-i5205932.service: Main process exited, code=exited, status=217/USER
systemd[1]: run-p1013202-i5205932.service: Failed with result 'exit-code'.
This allows a service to reuse the user namespace created for an
existing service, similarly to NetworkNamespacePath=. The configuration
is the initial user namespace (e.g. ID mapping) is preserved.
If socket is used as stdio, we'd currently imply EXEC_PASS_FDS
and dump the whole set of fds to the control processes. This is
pretty much unexpected and unnecessary though, instead let's
pass only the socket fds.
Yes, this is a compat break, but a relatively minor one I'd
argue. And we can always revisit things if users do complain.
Otherwise, e.g. requesting to start a unit that is under stopping may
enter the failed state.
This makes
- rename .can_start() -> .test_startable(), and make it allow to return
boolean and refuse to start units when it returns false,
- refuse earlier to start units that are in the deactivating state, so
several redundant conditions in .start() can be dropped,
- move checks for unit states mapped to UNIT_ACTIVATING from .start() to
.test_startable().
Fixes#39247.
We had errno_to_name() which works for "known" errnos, and returns NULL for
unknown ones, and then ERRNO_NAME which always returns an answer, possibly just
a number as a string, but requires a helper buffer.
It is possible for the kernel to add a new errno. We recently learned that some
architectures define custom errno names. Or for some function to unexpectedly
return a bogus errno value. In almost all cases it's better to print that value
rather than "n/a" or "(null)". So let's use ERRNO_NAME is most error handling
code. Noteably, our code wasn't very good in handling the potential NULL, so
in various places we could print "(null)". Since this is supposed to be used
most of the time, let's shorten the names to ERRNO_NAME/errno_name.
There are a few places where we don't want to use the fallback path, in
particular for D-Bus error names or when saving the error name. Let's rename
errno_to_name() to errno_name_no_fallback() to make the distinction clearer.
log_unit_warning() already prints the full unit name, so we don't need to say
that it is a socket unit. And in technical messages articles like "the" are
generally skipped to make the messages shorter. Use simpler tense and simpler
wording.
Example from log: fedora.local systemd[1]: systemd-initctl.socket: Socket unit
configuration has changed while unit has been running, no open socket file
descriptor left. The socket unit is not functional until restarted.
This is just too wordy and says "socket" four times.
Alternative to b50f6dbe57
The commit naively returned early from socket_enter_running(), which however
is quite problematic, as the socket will be woken up over and over again
without doing a thing, until we eventually hit Poll/TriggerLimit*=.
On top of that it requires hacks to hold the start job for initrd-switch-root.service
up. Overall I doubt that is the right approach.
Let's instead hook this into our job engine, and try to activate
the service again when some other units are stopped. If all installed
jobs have been run yet we're still seeing the conflict or the manually
selected timeout is reached, fail the socket as before.
This controls the new SO_PASSRIGHTS socket option in kernel v6.16.
Note that I intentionally choose a different naming scheme than
Pass*=, since all other Pass*= options controls whether some extra
bits are attached to the message, while this one's about denying
file descriptor transfer and it feels more explicit this way.
And diverging from underlying socket option name is precedented
by Timestamping=. But happy to change it to just say PassRights=
if people disagree.
On linux sockets have a really good, unique identifier, the SO_COOKIE,
which is used by sockdiag and BPF and elsewhere. Let's expose this more
prominently in the service name of per-connection services invoked via
Accept=yes sockets.
This is really nice, because together with our $SO_COOKIE env var we can
now match up services, process execution contexts, and "ss" outputs, BPF
rules, and more.
Note, BPF_PROG_TYPE_CGROUP_SKB is supported since kernel v4.10, and
BPF_F_ALLOW_MULTI and program name is supported since kernel v4.15.
As our baseline on the kernel is v5.4, we can assume that the type,
flag, and naming is supported when bpf_program_supported() succeeds.
On Linux, read() on a message queue descriptor returns the message
queue statistics, not the actual message queue data. We need to use
mq_receive() to drain the queues instead.
Fixes a problem where a POSIX message queue socket unit with messages
in the queue at shutdown time could result in a hang on reboot/shutdown.
Currently there are various circular dependencies between headers
in core/. Let's get rid of these by making judicious use of forward
declarations and moving includes into implementation files instead of
having them in header files.
Getting rid of circular header includes simplifies the code and makes
various clang based tooling such as iwyu work much better on our code.
The most important change is getting rid of the manager.h include in
unit.h which is possible thanks to the previous commits. We also move
the OOMPolicy and StatusType enums to unit.h to remove the need for
other unit headers to include manager.h to get access to these enums.
Admittedly, some of our glyphs _are_ special, e.g. "O=" for SPECIAL_GLYPH_TOUCH ;)
But we don't need this in the name. The very long names make some invocations
very wordy, e.g. special_glyph(SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY).
Also, I want to add GLYPH_SPACE, which is not special at all.
Prior to this commit, if no Exec*= is defined for socket,
and the unit was in SOCKET_FAILED state, failure of socket_open_fds()
would induce state transition SOCKET_FAILED -> SOCKET_FAILED,
and OnFailure= deps get unexpectedly skipped. Let's introduce
an intermediate state, so that during unit start we enter
UNIT_ACTIVATING at least once.
Fixes#35635
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Michael Vogt
Lennart Poettering
Mike Yuan
Daan De Meyer
Luca Boccassi
Yu Watanabe
Marc-Antoine Riou
Zbigniew Jędrzejewski-Szmek
Quentin Deslandes
Todd C. Miller