This new flag controls whether to consider a problem if the referenced path
doesn't actually exist. If specified it's OK if the final file doesn't exist.
Note that this permits one or more final components of the path not to exist,
but these must not contain "../" for safety reasons (or, to be extra safe,
neither "./" and a couple of others, i.e. what path_is_safe() permits).
This new flag is useful when resolving paths before issuing an mkdir() or
open(O_CREAT) on a path, as it permits that the file or directory is created
later.
The return code of chase_symlinks() is changed to return 1 if the file exists,
and 0 if it doesn't. The latter is only returned in case CHASE_NON_EXISTING is
set.
Let's remove chase_symlinks_prefix() and instead introduce a flags parameter to
chase_symlinks(), with a flag CHASE_PREFIX_ROOT that exposes the behaviour of
chase_symlinks_prefix().
Previously, we'd generate an EINVAL error if it is attempted to escape a root
directory with relative ".." symlinks. With this commit this is changed so that
".." from the root directory is a NOP, following the kernel's own behaviour
where /.. is equivalent to /.
As suggested by @keszybz.
Let's use chase_symlinks() everywhere, and stop using GNU
canonicalize_file_name() everywhere. For most cases this should not change
behaviour, however increase exposure of our function to get better tested. Most
importantly in a few cases (most notably nspawn) it can take the correct root
directory into account when chasing symlinks.
strtoul() parses leading whitespace and an optional sign;
check that the first character is a digit to prevent odd
specifications like "00: 00: 00" and "-00:+00/-1".
"*-*~1" => The last day of every month
"*-02~3..5" => The third, fourth, and fifth last days in February
"Mon 05~07/1" => The last Monday in May
Resolves#3861
core: add new RestrictNamespaces= unit file setting
Merging, not rebasing, because this touches many files and there were tree-wide cleanups in the mean time.
We don't have plural in the name of any other -util files and this
inconsistency trips me up every time I try to type this file name
from memory. "formats-util" is even hard to pronounce.
This new setting permits restricting whether namespaces may be created and
managed by processes started by a unit. It installs a seccomp filter blocking
certain invocations of unshare(), clone() and setns().
RestrictNamespaces=no is the default, and does not restrict namespaces in any
way. RestrictNamespaces=yes takes away the ability to create or manage any kind
of namspace. "RestrictNamespaces=mnt ipc" restricts the creation of namespaces
so that only mount and IPC namespaces may be created/managed, but no other
kind of namespaces.
This setting should be improve security quite a bit as in particular user
namespacing was a major source of CVEs in the kernel in the past, and is
accessible to unprivileged processes. With this setting the entire attack
surface may be removed for system services that do not make use of namespaces.
In case of running test-execute on systems with systemd < v232, several
tests like privatedevices or protectkernelmodules fail because
/run/systemd/inaccessible/ doesn't exist. In these cases, we should skip
tests to avoid unnecessary errors.
See also https://github.com/systemd/systemd/pull/4243#issuecomment-253665566
This stripping is contolled by a new boolean parameter. When the parameter
is true, it means that the caller does not care about the distinction between
initrd and real root, and wants to act on both rd-dot-prefixed and unprefixed
parameters in the initramfs, and only on the unprefixed parameters in real
root. If the parameter is false, behaviour is the same as before.
Changes by caller:
log.c (systemd.log_*): changed to accept rd-dot-prefix params
pid1: no change, custom logic
cryptsetup-generator: no change, still accepts rd-dot-prefix params
debug-generator: no change, does not accept rd-dot-prefix params
fsck: changed to accept rd-dot-prefix params
fstab-generator: no change, custom logic
gpt-auto-generator: no change, custom logic
hibernate-resume-generator: no change, does not accept rd-dot-prefix params
journald: changed to accept rd-dot-prefix params
modules-load: no change, still accepts rd-dot-prefix params
quote-check: no change, does not accept rd-dot-prefix params
udevd: no change, still accepts rd-dot-prefix params
I added support for "rd." params in the three cases where I think it's
useful: logging, fsck options, journald forwarding options.
Fixes:
```
==10750==
==10750== HEAP SUMMARY:
==10750== in use at exit: 96 bytes in 3 blocks
==10750== total heap usage: 1,711 allocs, 1,708 frees, 854,545 bytes
allocated
==10750==
==10750== 96 (64 direct, 32 indirect) bytes in 1 blocks are definitely
lost in loss record 3 of 3
==10750== at 0x4C2DA60: calloc (vg_replace_malloc.c:711)
==10750== by 0x4EB3BDA: calendar_spec_from_string
(calendarspec.c:771)
==10750== by 0x109675: test_hourly_bug_4031 (test-calendarspec.c:118)
==10750== by 0x10A00E: main (test-calendarspec.c:202)
==10750==
==10750== LEAK SUMMARY:
==10750== definitely lost: 64 bytes in 1 blocks
==10750== indirectly lost: 32 bytes in 2 blocks
==10750== possibly lost: 0 bytes in 0 blocks
==10750== still reachable: 0 bytes in 0 blocks
==10750== suppressed: 0 bytes in 0 blocks
==10750==
==10750== For counts of detected and suppressed errors, rerun with: -v
==10750== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
```
When a unit file is invalid, we'd return an error without any details:
$ systemctl --root=/ enable testing@instance.service
Failed to enable: Invalid argument.
Fix things to at least print the offending file name:
$ systemctl enable testing@instance.service
Failed to enable unit: File testing@instance.service: Invalid argument
$ systemctl --root=/ enable testing@instance.service
Failed to enable unit, file testing@instance.service: Invalid argument.
A real fix would be to pass back a proper error message from conf-parser.
But this would require major surgery, since conf-parser functions now
simply print log errors, but we would need to return them over the bus.
So let's just print the file name, to indicate where the error is.
(Incomplete) fix for #4210.
