These three settings only make sense within the context of actual unit
files, hence filter this out when applied to the per-manager default,
and generate a log message about it.
These new settings permit specifiying arbitrary paths as
stdin/stdout/stderr locations. We try to open/create them as necessary.
Some special magic is applied:
1) if the same path is specified for both input and output/stderr, we'll
open it only once O_RDWR, and duplicate them fd instead.
2) If we an AF_UNIX socket path is specified, we'll connect() to it,
rather than open() it. This allows invoking systemd services with
stdin/stdout/stderr connected to arbitrary foreign service sockets.
Fixes: #3991
Let's make sure to process the fdname first, before changing the actual
input/output setting, since the fdname part can fail due to OOM.
This way we don't leave half-initialized bits around.
property_get_output_fdname() already had two different control flows for
stdout and stderr, it might as well handle stdin too, thus shortening
our code a bit.
Whether seccomp is supported or not is a server implementation detail,
the client should not be altered by that, and clients should be able to talk
to servers configured differently than the client, hence drop the
HAVE_SECCOMP ifdeffery here.
(This would be different if we'd need libseccomp or so to implement the
client, but we don't)
Both permit configuring data to pass through STDIN to an invoked
process. StandardInputText= accepts a line of text (possibly with
embedded C-style escapes as well as unit specifiers), which is appended
to the buffer to pass as stdin, followed by a single newline.
StandardInputData= is similar, but accepts arbitrary base64 encoded
data, and will not resolve specifiers or C-style escapes, nor append
newlines.
This may be used to pass input/configuration data to services, directly
in-line from unit files, either in a cooked or in a more raw format.
If the string length is specified as (size_t) -1, let's use that as
indicator for determining the length on our own. This makes it
slightlier shorter to invoke these APIs for a very common case.
Also, do some minor other coding style updates, and add assert()s here
and there.
All this function does is place some data in an in-memory read-only fd,
that may be read back to get the original data back.
Doing this in a way that works everywhere, given the different kernels
we support as well as different privilege levels is surprisingly
complex.
Mostly coding style fixes, but most importantly, initialize
c->std_input only after we know the free_and_strdup() invocation
succeeded, so that we don't leave half-initialized fields around on
failure.
Given that Linux assigns the same ioctl numbers ot multiple subsystems,
we should be careful when invoking ioctls, so that we don't end up
calling something we wouldn't want to call.
We are using the same pattern at various places: call dup2() on an fd,
and close the old fd, usually in combination with some O_CLOEXEC
fiddling. Let's add a little helper for this, and port a few obvious
cases over.
Before this, assigning empty string to Delegate= makes no change to the
controller list. This is inconsistent to the other options that take list
of strings. After this, when empty string is assigned to Delegate=, the
list of controllers is reset. Such behavior is consistent to other options
and useful for drop-in configs.
Closes#7334.
This option is likely to be very useful for systemd-run invocations,
hence let's add a shortcut for it.
With this new concepts it's now very easy to put together systemd-run
invocations that leave zero artifacts in the system, including when they
fail.
Right now, the option only takes one of two possible values "inactive"
or "inactive-or-failed", the former being the default, and exposing same
behaviour as the status quo ante. If set to "inactive-or-failed" units
may be collected by the GC logic when in the "failed" state too.
This logic should be a nicer alternative to using the "-" modifier for
ExecStart= and friends, as the exit data is collected and logged about
and only removed when the GC comes along. This should be useful in
particular for per-connection socket-activated services, as well as
"systemd-run" command lines that shall leave no artifacts in the
system.
I was thinking about whether to expose this as a boolean, but opted for
an enum instead, as I have the suspicion other tweaks like this might be
a added later on, in which case we extend this setting instead of having
to add yet another one.
Also, let's add some documentation for the GC logic.
When preparing for a restart we quickly go through the DEAD/INACTIVE
service state before entering AUTO_RESTART. When doing this, we need to
make sure we don't destroy the FD store. Previously this was done by
checking the failure state of the unit, and keeping the FD store around
when the unit failed, under the assumption that the restart logic will
then get into action.
This is not entirely correct howver, as there might be failure states
that will no result in restarts.
With this commit we slightly alter the logic: a ref counter for the fd
store is added, that is increased right before we handle the restart
logic, and decreased again right-after.
This should ensure that the fdstore lives exactly as long as it needs.
Follow-up for f0bfbfac43.
And let's make use of it to implement two new unit settings with it:
1. LogLevelMax= is a new per-unit setting that may be used to configure
log priority filtering: set it to LogLevelMax=notice and only
messages of level "notice" and lower (i.e. more important) will be
processed, all others are dropped.
2. LogExtraFields= is a new per-unit setting for configuring per-unit
journal fields, that are implicitly included in every log record
generated by the unit's processes. It takes field/value pairs in the
form of FOO=BAR.
Also, related to this, one exisiting unit setting is ported to this new
facility:
3. The invocation ID is now pulled from /run/systemd/units/ instead of
cgroupfs xattrs. This substantially relaxes requirements of systemd
on the kernel version and the privileges it runs with (specifically,
cgroupfs xattrs are not available in containers, since they are
stored in kernel memory, and hence are unsafe to permit to lesser
privileged code).
/run/systemd/units/ is a new directory, which contains a number of files
and symlinks encoding the above information. PID 1 creates and manages
these files, and journald reads them from there.
Note that this is supposed to be a direct path between PID 1 and the
journal only, due to the special runtime environment the journal runs
in. Normally, today we shouldn't introduce new interfaces that (mis-)use
a file system as IPC framework, and instead just an IPC system, but this
is very hard to do between the journal and PID 1, as long as the IPC
system is a subject PID 1 manages, and itself a client to the journal.
This patch cleans up a couple of types used in journal code:
specifically we switch to size_t for a couple of memory-sizing values,
as size_t is the right choice for everything that is memory.
Fixes: #4089Fixes: #3041Fixes: #4441
When we drop messages of a unit, we log about. Let's add some structured
data to that. Let's include how many messages we dropped, but more
importantly, let's link up the message we generate to the unit we
dropped the messages from by using the "OBJECT" logic, i.e. by
generating OBJECT_SYSTEMD_UNIT= fields and suchlike, that "journalctl
-u" and friends already look for.
Fixes: #6494
In chroot environments, /etc might not be fully initialized: /etc/machine-id
can be missing for example. This makes the expansions of affected specifiers
impossible at that time.
These cases should not be considered as errors and such failures shouldn't be
logged at an error level therefore this patch downgrades the level used to
LOG_NOTICE in such cases.
Also this is logged at LOG_NOTICE only the first time and then downgrade to
LOG_DEBUG for the rest. That way, if debugging is enabled we get the full
output, but otherwise we only see only one message.
The expansion of specifiers is now self contained in a dedicated function
instead of being spread all over the place.
Implement DHCPv6 option to exchange information about the Fully
Qualified Domain Name (FQDN) according to RFC 4704.
The RFC 4704 describes two models of operations in section 3,
currently only the second model is supported (DHCPv6 server
updates both the AAAA and the PTR RRs).
The existing DHCP Section Options SendHostname and Hostname are
sent as FQDN to the server. According to section 4.2 sending
only parts of its FQDN is allowed.
Fixes#4682.
Technically DNS allows any ASCII character to be used in the
domain name. Also the DHCP specification for the FQDN option
(RFC 4702) does not put restriction on labels.
However, hostnames do have stricter requirements and typically
should only use characters from a-z (case insensitve), 0-9 and
minus.
Currently we require hostname/FQDN to be either a hostname or
a valid DNS name. Since dns_name_is_valid() allows any ASCII
characters this allows to specify hostnames which are typically
not valid.
Check hostname/FQDN more strictly and require them to pass both
tests. Specifically this requires the entire FQDN to be below 63.
We would continue, but still return an error at the end. This isn't useful
because we'd still error-out in main().
Also, add a missing error message when we fail to mkdir.
It is possible that kernel will reject our netlink message that
configures the link. However, we should always make sure that interface
will be named properly otherwise we can leave interfaces having
unpredictable kernel names. Thus we don't return early and continue to
export name and link file properties.
Suggested-by: Tom Gundersen <teg@jklm.no>
SetLinger is authorized by the PolicyKit action "set-self-linger", if it is
not passed an explicit UID.
According to comments we were determining the default UID from the client's
session. However, user processes e.g. which are run from a terminal
emulator do not necessarily belong to a session scope unit. They may
equally be started from the systemd user manager [1][2]. Actually the
comment was wrong, and it would also have worked for processes
started from the systemd user manager.
Nevertheless it seems to involve fetching "augmented credentials" i.e.
it's using a racy method, so we shouldn't have been authenticating based
on it.
We could change the default UID, but that raises issues especially for
consistency between the methods. Instead we can just use the clients
effective UID for authorization.
This commit also fixes `loginctl enable-linger $USER` to match the docs
that say it was equivalent to `loginctl enable-linger` (given that $USER
matches the callers user and owner_uid). Previously, the former would not
have suceeded for unpriviliged users in the default configuration.
[1] It seems the main meaning of per-session scopes is tracking the PAM
login process. Killing that provokes logind to revoke device access. Less
circularly, killing it provokes getty to hangup the TTY.
[2] User units may be started with an environment which includes
XDG_SESSION_ID (presuambly GNOME does this?). Or not.
