So glibc exposes a close_range() syscall wrapper now, but they decided
to use "unsigned" as type for the fds. Which is a bit weird, because fds
are universally understood to be "int". The kernel internally uses
"unsigned", both for close() and for close_range(), but weirdly,
userspace didn't fix that for close_range() unlike what they did for
close()... Weird.
But anyway, let's follow suit, and make our wrapper match glibc's.
Fixes#31270
Previously, if given an absolute path, we would open the file, but when given a
relative path, we'd attempt to search the directories. If the user wants to open
a file from the search path, allowing paths is very confusing. E.g. with a path
like 'sysusers/foo.conf', we'd try to open '/etc/sysusers.d/sysusers/foo.conf',
'/run/sysusers.d/sysusers/foo.conf', …, and with '../foo.conf', we'd try to open
'/etc/sysusers.d/../foo.conf', '/run/sysusers.d/../foo.conf', …. This just isn't
useful, and in fact for a scheme like sysusers.d and tmpfiles.d where there we
have a flat directory with config files, only searching for plain names can
result in success. When a user specifies a relative path, it's more likely that
they wanted to open some local file. OTOH, to correctly open a local file, e.g.
one that they're just writing, this interface is also awkward, because something
like '$PWD/file.conf' has to be used to open a file with a relative path.
This patch changes the interface so that any path (i.e. an argument with "/") is
used to open a file directly, and only plain basenames are used for searching.
(Note that tpmfiles and sysusers are somewhat special here: their "config files"
make sense without the other config and users are likely to want to test them
without the other config. I was trying to do just that when writing a spec file
for a package and attempting to convert the existing scripts to sysusers and
tmpfiles. The same logic wouldn't apply for example to units or udev rules,
because they generally can only be interpreted with the whole rest of config
also available.)
I was annoyed that systemd-sysusers doesn't print any info when it opens a
config file. Its read_config_file() started out the same as the one in tmpfiles,
and then they diverged. The one in tmpfiles has that logging, hence the rework
to use it here too and get better logging. The two programs should provide
similar functionality, so using a common helper will make it easier to extend
them in tandem later.
No functional change apart from the log info.
The userdata argument (Context) is moved to the last position as requested in
the review.
The personality() syscall returns a 32-bit value where the top three
bytes are reserved for flags that emulate historical or architectural
quirks, and only the least significant byte reflects the actual
personality we're interested in (in opinionated_personality()).
Use the newly defined mask in the corresponding test as well, otherwise
the test fails on some more "exotic" architectures that set some of the
"quirk" flags:
~# uname -m
armv7l
~# build/test-seccomp
...
/* test_lock_personality */
current personality=0x0
safe_personality(PERSONALITY_INVALID)=0x800000
Assertion '(unsigned long) safe_personality(current) == current' failed at src/test/test-seccomp.c:970, function test_lock_personality(). Aborting.
lockpersonalityseccomp terminated by signal ABRT.
Assertion 'wait_for_terminate_and_check("lockpersonalityseccomp", pid, WAIT_LOG) == EXIT_SUCCESS' failed at src/test/test-seccomp.c:996, function test_lock_personality(). Aborting.
Aborted (core dumped)
See: personality(2) and comments in sys/personality.h
posix_spawnattr_setflags() doesn't OR the input to the current set of flags,
it overwrites them, so we are currently losing POSIX_SPAWN_SETSIGDEF.
Follow-up for: 6ecdfe7d10
This commit overhauls the way freeze/thaw works recursively:
First, it introduces new FreezerActions that are like the existing
FREEZE and THAW but indicate that the action was initiated by a parent
unit. We also refactored the code to pass these FreezerActions through
the whole call stack so that we can make use of them. FreezerState was
extended similarly, to be able to differentiate between a unit that's
frozen manually and a unit that's frozen because a parent is frozen.
Next, slices were changed to check recursively that all their child
units can be frozen before it attempts to freeze them. This is different
from the previous behavior, that would just check if the unit's type
supported freezing at all. This cleans up the code, and also ensures
that the behavior of slices corresponds to the unit's actual ability
to be frozen
Next, we make it so that if you FREEZE a slice, it'll PARENT_FREEZE
all of its children. Similarly, if you THAW a slice it will PARENT_THAW
its children.
Finally, we use the new states available to us to refactor the code
that actually does the cgroup freezing. The code now looks at the unit's
existing freezer state and the action being requested, and decides what
next state is most appropriate. Then it puts the unit in that state.
For instance, a RUNNING unit with a request to PARENT_FREEZE will
put the unit into the PARENT_FREEZING state. As another example, a
FROZEN unit who's parent is also FROZEN will transition to
PARENT_FROZEN in response to a request to THAW.
Fixes https://github.com/systemd/systemd/issues/30640
Fixes https://github.com/systemd/systemd/issues/15850
By definition, a parameter cannot contain a comma because commas
are used to delimit parameters. So we also don't need to use parens
when the use site is delimited by commas.
We do this for getgroups_malloc() hence we should do this here too,
after all whether we do it for a socket peer or for ourselves doesn't
make too much of a difference.
We can only delegate actual controllers, not the BPF pseudo-controllers
we defined as there's imply no concept for that. Hence, when users set
Delegate=yes to do a wildcard delegation, only delegate the regular
controllers.
This means that we won't bother with BPF stuff for such units where it's
entirelly unnecessary.
The RA's Retransmission Timer field was being ignored. This resolves the IPv6
Core Conformance test, v6LC.2.1.5 [1].
Retransmission Timer is a 32-bit unsigned integer. The time, in milliseconds,
between retransmitted Neighbor Solicitation messages. Used by the Address
Resolution and Neighbor Unreachability Detection (NUD) algorithm.
Support setting a default value for the neighbour retransmission timer value with:
[Network]
IPv6RetransmissionTimeSec=<int>
By default, upon receiving a Router Advertisement with the Retransmission Timer
field set to a non-zero value, it will update the kernel's retransmit timer value.
To disable this behaviour, configure the UseIPv6RetransmissionTime= under the
[IPv6AcceptRA] section.
[IPv6AcceptRA]
UseIPv6RetransmissionTime=<bool>
RFC4861: Neighbor Discovery in IPv6
* Section 4.2 RA Message Format.
* Section 6.3.4 Processing Received Router Advertisements
A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time,
and Retrans Timer) may contain a value denoting that it is
unspecified. In such cases, the parameter should be ignored and the
host should continue using whatever value it is already using. In
particular, a host MUST NOT interpret the unspecified value as
meaning change back to the default value that was in use before the
first Router Advertisement was received.
The RetransTimer variable SHOULD be copied from the Retrans Timer
field, if the received value is non-zero.
References
[1] IPv6 Core Conformance Spec (PDF)
Lennart Poettering
Luca Boccassi
Sam Leonard
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Frantisek Sumsal
Mike Yuan
mille-feuille
Vladimir Stoiakin
Yu Watanabe
Adrian Vovk
Matt Muggeridge