Yu Watanabe [Tue, 4 May 2021 05:40:56 +0000 (14:40 +0900)]
path-util: make path_extract_filename/directory() handle "." gracefully
This makes the functions handle "xx/" and "xx/." as equivalent.
Moreover, now path_extract_directory() returns normalized path, that is
no redundant "/" or "/./" are contained.
meson: Correctly validate that prefix is a child of rootprefix
In commit d895e10a a test was introduced to validate that prefix is a
child of rootprefix. However, it only works when rootprefix is "/".
Since the test is ignored when rootprefix is equal to prefix, this is
only noticed if specifying both -Drootprefix= and -Dprefix=, e.g.:
$ meson foo -Drootprefix=/foo -Dprefix=/foo/bar
meson.build:111:8: ERROR: Problem encountered: Prefix is not below
root prefix (now rootprefix=/foo prefix=/foo/bar)
hash-func: change value type of string_hash_ops_free_free to void*
The generic string_hash_ops_free_free hash operations vtable currently
assumes the data pointer is of type char*. There's really no reason to
assume that though, we regularly store non-string data as value in a
hashmap. Hence, to accomodate for that, use void* as pointer for the
value (and keep char* for the key, as that's what
string_hash_ops_free_free is for, after all).
udevadm: make use of the new uuid-enabled triggering for "udevadm trigger"
This adds two things:
- A new switch --uuid is added to "udevadm trigger". If specified a
random UUID is associated with the synthettic uevent and it is printed
to stdout. It may then be used manually to match up uevents as they
propagate through the system.
- The UUID logic is now implicitly enabled if "udevadm trigger --settle"
is used, in order to wait for precisely the uevents we actually
trigger. Fallback support is kept for pre-4.13 kernels (where the
requests for trigger uevents with uuids results in EINVAL).
sd-device: add API for triggering synthetic uevents with UUID
Since kernel 4.13 the kerne allows passing a UUID to generated uevents.
Optionally do so via a new sd_device_trigger_with_uuid() call, and add
sd_device_get_trigger_uuid() as helper to retrieve the UUID from a
uevent we receive.
This is useful for tracking uevents through the udev system, and waiting
for specific triggers.
(Note that the 4.13 patch allows passing arbitrary meta-info into the
uevent as well. This does not add an API for that, because I am not
convinced it makes sense — as it conflicts with our general rule that
events are "stateless" if you so will — and it complicates the interface
quite a bit).
This replaces #13881 in a way, which added a similar infra, but which
stalled, and whose synchronous settling APIs are somewhat problematic
and probably not material to merge.
man: document that it is guaranteed that generated ID128 are never all-zero or all-one
This is the case because the ID128 we generate are all marked as v4 UUID
which requires that some bits are zero and others are one. Let's
document this so that people can rely on SD_ID128_NULL being a special
value for "uninitialized" that is always distinguishable from generated
UUIDs.
Topi Miettinen [Fri, 22 Jan 2021 15:14:50 +0000 (17:14 +0200)]
Mount all fs nosuid when NoNewPrivileges=yes
When `NoNewPrivileges=yes`, the service shouldn't have a need for any
setuid/setgid programs, so in case there will be a new mount namespace anyway,
mount the file systems with MS_NOSUID.
The code works differently than the docs, and the code is right here.
Fix the doc hence.
See VALID_CHARS in unit-name.c for details about allowed chars in unit
names, but keep in mind that "-" and "\" are special, since generated by
the escaping logic: they are OK to show up in unit names, but need to be
escaped when converting foreign strings to unit names to make sure
things remain reversible.
core: support specifier expansion in DefaultEnvironment= and ManagerEnvironment=
Strictly speaking adding this is a compatibility break, given that
previously % weren't special. But I'd argue that was simply a bug, as
for the much more prominent Environment= service setting we always
resolved specifiers, and DEfaultEnvironment= is explicitly listed as
being the default for that. Hence, let's fix that.
This might be useful for CopyFiles=, to reference some subdir of $TMP in
a generic way. This allows us to use the new common
system_and_tmp_specifier_table[].
sysusers: add a generic specifier table for common cases
This moves the definition of the specifier table consisting only of
system and /tmp specifiers into generic code so that we can share it.
This patch only adds one user of it for now. Follow-up patches will add
more.
networkctl: politely refuse being called from a different netns than the networkd instance we talk to
Otherwise things get very confusing since we mix up netens data from our
client side and from the data we retrieve from networkd.
In the long run we should teach networkctl some switch to operate safely
on other netns, and in that case also determine the right networkd
instance for that namespace.
networkd: add bus property exposing network namepace ID we run in
This is useful for clients to determine whether they are running in the
same network namespace as networkd.
Note that access to /proc/$PID/ns/ is restricted and only permitted to
equally privileged programs. This new bus property is primarily a way to
work around this, so that unprivileged clients can determine the
networkd netns, too.
When watching paths that contain symlinks in some element we so far
always only watched the inode they are pointing to, not the symlink
inode itself. Let's fix that and always watch both. We do this by simply
installing the inotify watch once with and once without IN_DONT_FOLLOW.
For non-symlink inodes this just overrides the same watch twice (where
the second one replaces the first), which is has no effect effectively.
For symlinks it means we'll watch both source and destination.
core: reorder where we add units to queues in unit_notify()
This moves all calls that shall do deferred work on detecting whether to
start/stop the unit or dependent units after a unit state change to the
end of the function, to make things easier to read.
So far, these calls were spread all over the function, and
conditionalized needlessly on MANAGER_RELOADING(). This is unnecessary,
since the queues are not dispatched while reloading anyway, and
immediately before acting on a queued unit we'll check if the suggested
operation really makes sense.
The only conditionalizaiton we leave in is on checking the new unit
state itself, since we have that in a local variable anyway.
core: change BoundBy= dependency handling to be processed by a deferred work queue
So far StopWhenUnneeded= handling and UpheldBy= handling was already
processed by a queue that is dispatched in a deferred mode of operation
instead of instantly. This changes BoundBy= handling to be processed the
same way.
This should ensure that all *event*-to-job propagation is done directly
from unit_notify(), while all *state*-to-job propagation is done from a
deferred work queue, quite systematically. The work queue is submitted
to by unit_notify() too.
Key really is the difference between event and state: some jobs shall be
queued one-time on events (think: OnFailure= + OnSuccess= and similar),
others shall be queued continuously when a specific state is in effect
(think: UpheldBy=). The latter cases are usually effect of the
combination of states of a few units (e.g. StopWhenUnneeded= checks
wether any of the Wants=/Requires=/… deps are still up before acting),
and hence it makes sense to trigger them to be run after an individual
unit's state changed, but process them on a queue that runs whenever
there's nothing else to do that ensures the decision on them is only
taken after all jobs/queued IO events are dispatched, and things
settled, so that it makes sense to come to a combined conclusion. If
we'd dispatch this work immediately inside of unit_notify() we'd always
act instantly, even though another event from another unit that is
already queued might make the work unnecessary or invalid.
This is mostly a commit to make things philosophically clean. It does
not add features, but it should make corner cases more robust.
This is like a really strong version of Wants=, that keeps starting the
specified unit if it is ever found inactive.
This is an alternative to Restart= inside a unit, acknowledging the fact
that whether to keep restarting the unit is sometimes not a property of
the unit itself but the state of the system.
This implements a part of what #4263 requests. i.e. there's no
distinction between "always" and "opportunistic". We just dumbly
implement "always" and become active whenever we see no job queued for
an inactive unit that is supposed to be upheld.
This is similar to OnFailure= but is activated whenever a unit returns
into inactive state successfully.
I was always afraid of adding this, since it effectively allows building
loops and makes our engine Turing complete, but it pretty much already
was it was just hidden.
Given that we have per-unit ratelimits as well as an event loop global
ratelimit I feel safe to add this finally, given it actually is useful.
core: add new PropagateStopTo= dependency (and inverse)
This takes inspiration from PropagatesReloadTo=, but propagates
stop jobs instead of restart jobs.
This is defined based on exactly two atoms: UNIT_ATOM_PROPAGATE_STOP +
UNIT_ATOM_RETROACTIVE_STOP_ON_STOP. The former ensures that when the
unit the dependency is originating from is stopped based on user
request, we'll propagate the stop job to the target unit, too. In
addition, when the originating unit suddenly stops from external causes
the stopping is propagated too. Note that this does *not* include the
UNIT_ATOM_CANNOT_BE_ACTIVE_WITHOUT atom (which is used by BoundBy=),
i.e. this dependency is purely about propagating "edges" and not
"levels", i.e. it's about propagating specific events, instead of
continious states.
This is supposed to be useful for dependencies between .mount units and
their backing .device units. So far we either placed a BindsTo= or
Requires= dependency between them. The former gave a very clear binding
of the to units together, however was problematic if users establish
mounnts manually with different block device sources than our
configuration defines, as we there might come to the conclusion that the
backing device was absent and thus we need to umount again what the user
mounted. By combining Requires= with the new StopPropagatedFrom= (i.e.
the inverse PropagateStopTo=) we can get behaviour that matches BindsTo=
in every single atom but one: UNIT_ATOM_CANNOT_BE_ACTIVE_WITHOUT is
absent, and hence the level-triggered logic doesn't apply.
Let's add an implicit reverse dep OnFailureOf=. This is exposed via the
bus to make things more debuggable: you can now ask systemd for which
units a specific unit is the failure handler.
OnFailure= was the only dependency type that had no inverse, this fixes
that.
Now that deps are a bit cheaper, it should be OK to add deps that only
serve debug purposes.
core: convert Slice= into a proper dependency (and add a back dependency)
The slice a unit is assigned to is currently a UnitRef reference. Let's
turn it into a proper dependency, to simplify and clean up code a bit.
Now that new dep types are cheaper, deps should generally be preferable
over everything else, if the concept applies.
This brings one major benefit: we often have to iterate through all unit
a slice contains. So far we iterated through all Before= dependencies of
the slice unit to achieve that, filtering out unrelated units, and
taking benefit of the fact that slice units are implicitly ordered
Before= the units they contain. By making Slice= a proper dependency,
and having an accompanying SliceOf= dependency type, this is much
simpler and nicer as we can directly enumerate the units a slice
contains.
The forward dependency is actually called InSlice internally, since we
already used the UNIT_SLICE name as UnitType field. However, since we
don't intend to expose the dependency to users as dep anyway (we already
have the regular Slice D-Bus property for this) this shouldn't matter.
The SliceOf= implicit dependency type (the erverse of Slice=/InSlice=)
is exported over the bus, to make things a bit nicer to debug and
discoverable.
In a later commit we intend to move the slice logic to use proper
dependencies instead of a "UnitRef" object. This preparatory commit
drops direct use of the slice UnitRef object for a static inline
function UNIT_GET_SLICE() that is both easier to grok, and allows us to
easily replace its internal implementation later on.
Luca Boccassi [Sun, 23 May 2021 12:43:38 +0000 (13:43 +0100)]
meson: look for bpftool in /usr/sbin too
On Debian, bpftool is installed in /usr/sbin, which is not in $PATH for
non-root users by default, so finding it fails.
Add a secondary, hard-coded '/usr/sbin/bpftool' after 'bpftool' so that
meson can find it.