These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
To make debugging easier, this patches allows one to change the log target and
do reload/reexec without modifying configuration permanently, which makes
debugging easier.
Indeed if one changed the log target at runtime (via the bus or via signals),
the change was lost on the next reload/reexecution.
In order to restore back the default value (set via system.conf, environment
variables or any other means ), the empty string in the "LogTarget" property is
now supported as well as sending SIGTRMIN+26 signal.
To make debugging easier, this patches allows one to change the log level and
do reload/reexec without modifying configuration permanently, which makes
debugging easier.
Indeed if one changed the log max level at runtime (via the bus or via
signals), the change was lost on the next daemon reload/reexecution.
In order to restore the original value back (set via system.conf, environment
variables or any other means), the empty string in the "LogLevel" property is
now supported as well as sending SIGRTMIN+23 signal.
Let's use a switch() statement, cover more cases with pretty messages.
Also let's rename it to "validate", as that's more specific that
"check", as it implies checking for a "valid"/"good" state, which is
what this function does.
It is not const, because a) systemd can bump it on its own if
errors occur, and b) the user can change it using signals.
Also it's not boolean.
$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager ShowStatus
b true
$ sudo kill -SIGRTMIN+21 1
$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager ShowStatus
b false
Fixes#4503.
Previously we were a bit sloppy with the index and size types of arrays,
we'd regularly use unsigned. While I don't think this ever resulted in
real issues I think we should be more careful there and follow a
stricter regime: unless there's a strong reason not to use size_t for
array sizes and indexes, size_t it should be. Any allocations we do
ultimately will use size_t anyway, and converting forth and back between
unsigned and size_t will always be a source of problems.
Note that on 32bit machines "unsigned" and "size_t" are equivalent, and
on 64bit machines our arrays shouldn't grow that large anyway, and if
they do we have a problem, however that kind of overly large allocation
we have protections for usually, but for overflows we do not have that
so much, hence let's add it.
So yeah, it's a story of the current code being already "good enough",
but I think some extra type hygiene is better.
This patch tries to be comprehensive, but it probably isn't and I missed
a few cases. But I guess we can cover that later as we notice it. Among
smaller fixes, this changes:
1. strv_length()' return type becomes size_t
2. the unit file changes array size becomes size_t
3. DNS answer and query array sizes become size_t
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76745
This is useful for foreign container runtimes implementing the OCI
runtime spec, which only wants to deal with cgroup paths. There's
already an API to translate units into cgroup paths, with this we add
the reverse.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This rearranges chase_symlinks() a bit: if no special flags are
specified it will now revert to behaviour before
b12d25a8d6. However, if the new
CHASE_TRAIL_SLASH flag is specified it will follow the behaviour
introduced by that commit.
I wasn't sure which one to make the beaviour that requires specification
of a flag to enable. I opted to make the "append trailing slash"
behaviour the one to enable by a flag, following the thinking that the
function should primarily be used to generate a normalized path, and I
am pretty sure a path without trailing slash is the more "normalized"
one, as the trailing slash is not really a part of it, but merely a
"decorator" that tells various system calls to generate ENOTDIR if the
path doesn't refer to a path.
Or to say this differently: if the slash was part of normalization then
we really should add it in all cases when the final path is a directory,
not just when the user originally specified it.
Fixes: #8544
Replaces: #8545
This adds a new bus call to service and scope units called
AttachProcesses() that moves arbitrary processes into the cgroup of the
unit. The primary user for this new API is systemd itself: the systemd
--user instance uses this call of the systemd --system instance to
migrate processes if itself gets the request to migrate processes and
the kernel refuses this due to access restrictions.
The primary use-case of this is to make "systemd-run --scope --user …"
invoked from user session scopes work correctly on pure cgroupsv2
environments. There, the kernel refuses to migrate processes between two
unprivileged-owned cgroups unless the requestor as well as the ownership
of the closest parent cgroup all match. This however is not the case
between the session-XYZ.scope unit of a login session and the
user@ABC.service of the systemd --user instance.
The new logic always tries to move the processes on its own, but if
that doesn't work when being the user manager, then the system manager
is asked to do it instead.
The new operation is relatively restrictive: it will only allow to move
the processes like this if the caller is root, or the UID of the target
unit, caller and process all match. Note that this means that
unprivileged users cannot attach processes to scope units, as those do
not have "owning" users (i.e. they have now User= field).
Fixes: #3388
This splits out the code that translates a unit name into a Unit* object
from method_get_unit(), and reuses it all other functions that operate
similar to it. This effectively means all those calls now optionally
take an empty unit string which now means the same as the client's unit.
This useful behaviour of the GetUnit() bus call is thus extended to all
other matching bus calls.
Similar, the same logic from method_load_unit() is also generalized and
reused wherever appropriate.
StartLimitIntervalSec= and DefaultStartLimitIntervalSec= are the
last options whose suffix is 'Sec' instead of 'USec'.
All the other option has suffix 'USec'. So, let's rename them.
The tainting logic existed for a long time, but was hidden inside the
bus interfaces. Let's give it a small bit more coverage, by logging its
value early at boot during initialization.
Let's make our finished checks a bit more readable. Checking the
timestamp is not entirely obvious, hence let's abstract that a bit by
adding a macro that shows what we are doing here, not how we doing it.
This is particularly useful if we want to change the definition of
"finished" later on, in particular, when we try to fix#7023.
It's like manager_dump(), but returns a string. This allows us to reduce
some duplicate code. Also, while we are at it, turn off stdio locking
while we write to the memory FILE *f.
This makes things quite a bit more systematic I think, as we can
systematically operate on all timestamps, for example for the purpose of
serialization/deserialization.
This rework doesn't necessarily make things shorter in the individual
lines, but it does reduce the line count a bit.
(This is useful particularly when we want to add additional timestamps,
for example to solve #7023)
This reverts commit ee043777be.
It broke almost everywhere it touched. The places that
handn't been converted, were mostly followed by special
handling for the invalid PID `0`. That explains why they
tested for `pid < 0` instead of `pid <= 0`.
I think that one was the first commit I reviewed, heh.
In some cases there might be unit symlinks in .wants/ or .requires/
directories even though the unit is otherwise fully removed. In this
case, don't fail removal, but still remove the symlinks.
This reworks the symlink marking logic to always add unit files that we
are missing to the changes list, but proceed with any symlink removal
for them. This way we'll still generate useful hints that a unit is
missing if you invoke "systemctl disable idontexist.service", but also
still remove any link to it.
Fixes: #4995
Previously, we'd refuse the GetUnitProcesses() bus call if the unit file
couldn't be loaded. Which is wrong, as admins should be able to inspect
services whose unit files was deleted. Change this logic, so that we
permit introspecting the processes of any unit that is loaded,
regardless if it has a unit file or not.
(Note that we won't load unit files in GetUnitProcess(), but only
operate on already loaded ones. That's because only loaded units can
have processes — as that's how our GC logic works — and hence loading
the unit just for the process tree is pointless, as it would be empty).
See: #4995
Let's more verbose error messages when validating the input parameters fails.
Also, call path_is_os_tree() properly, as it doesn't return a boolean, but
possibly also an error. Finally, check for the existance of the new init
process with chase_symlinks() to properly handle possible symlinks on the init
binary (which might actually be pretty likely).
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.
It may be desired by users to know what targets a particular service is
installed into. Improve user friendliness by teaching the is-enabled
command to show such information when used with --full.
This patch makes use of the newly added UnitFileFlags and adds
UNIT_FILE_DRY_RUN flag into it. Since the API had already been modified,
it's now easy to add the new dry-run feature for other commands as
well. As a next step, --dry-run could be added to systemctl, which in
turn might pave the way for a long requested dry-run feature when
running systemctl start.
This adds a new invocation ID concept to the service manager. The invocation ID
identifies each runtime cycle of a unit uniquely. A new randomized 128bit ID is
generated each time a unit moves from and inactive to an activating or active
state.
The primary usecase for this concept is to connect the runtime data PID 1
maintains about a service with the offline data the journal stores about it.
Previously we'd use the unit name plus start/stop times, which however is
highly racy since the journal will generally process log data after the service
already ended.
The "invocation ID" kinda matches the "boot ID" concept of the Linux kernel,
except that it applies to an individual unit instead of the whole system.
The invocation ID is passed to the activated processes as environment variable.
It is additionally stored as extended attribute on the cgroup of the unit. The
latter is used by journald to automatically retrieve it for each log logged
message and attach it to the log entry. The environment variable is very easily
accessible, even for unprivileged services. OTOH the extended attribute is only
accessible to privileged processes (this is because cgroupfs only supports the
"trusted." xattr namespace, not "user."). The environment variable may be
altered by services, the extended attribute may not be, hence is the better
choice for the journal.
Note that reading the invocation ID off the extended attribute from journald is
racy, similar to the way reading the unit name for a logging process is.
This patch adds APIs to read the invocation ID to sd-id128:
sd_id128_get_invocation() may be used in a similar fashion to
sd_id128_get_boot().
PID1's own logging is updated to always include the invocation ID when it logs
information about a unit.
A new bus call GetUnitByInvocationID() is added that allows retrieving a bus
path to a unit by its invocation ID. The bus path is built using the invocation
ID, thus providing a path for referring to a unit that is valid only for the
current runtime cycleof it.
Outlook for the future: should the kernel eventually allow passing of cgroup
information along AF_UNIX/SOCK_DGRAM messages via a unique cgroup id, then we
can alter the invocation ID to be generated as hash from that rather than
entirely randomly. This way we can derive the invocation race-freely from the
messages.
This adds two (privileged) bus calls Ref() and Unref() to the Unit interface.
The two calls may be used by clients to pin a unit into memory, so that various
runtime properties aren't flushed out by the automatic GC. This is necessary
to permit clients to race-freely acquire runtime results (such as process exit
status/code or accumulated CPU time) on successful service termination.
Ref() and Unref() are fully recursive, hence act like the usual reference
counting concept in C. Taking a reference is a privileged operation, as this
allows pinning units into memory which consumes resources.
Transient units may also gain a reference at the time of creation, via the new
AddRef property (that is only defined for transient units at the time of
creation).
This adds a new boolean setting DynamicUser= to service files. If set, a new
user will be allocated dynamically when the unit is started, and released when
it is stopped. The user ID is allocated from the range 61184..65519. The user
will not be added to /etc/passwd (but an NSS module to be added later should
make it show up in getent passwd).
For now, care should be taken that the service writes no files to disk, since
this might result in files owned by UIDs that might get assigned dynamically to
a different service later on. Later patches will tighten sandboxing in order to
ensure that this cannot happen, except for a few selected directories.
A simple way to test this is:
systemd-run -p DynamicUser=1 /bin/sleep 99999
