This is useful for debugging client-side ref counting of units: for each
ref taken on a unit the client's sender name is listed. If a client has
multiple refs on the same unit it is listed multiple times.
This is the same as Abandon() on the Scope object, but saves clients
from first translating a unit name into a unit object path. This logic
matches how all the other unit methods have counterparts on the Manager
object too (e.g. StopUnit() on the Manager object matching Stop() on the
Unit object), this one was simply forgotten so far.
Behaviour is prett ymuch the same, but there's some additional type
checking done on the input parameters.
(In the case of UNIT_WRITE_FLAGS_NOOP() the C compiler won't actually do
the type checking necessarily, but static chckers at least could)
sysctl is disabled for /proc mounted from an user namespace thus entries like
/proc/sys/net/unix/max_dgram_qlen do not exist. In this case, skip the error
and do not try to change the default for the AF_UNIX datagram queue length.
This splits the "environment" field of Manager into two:
transient_environment and client_environment. The former is generated
from configuration file, kernel cmdline, environment generators. The
latter is the one the user can control with "systemctl set-environment"
and similar.
Both sets are merged transparently whenever needed. Separating the two
sets has the benefit that we can safely flush out the former while
keeping the latter during daemon reload cycles, so that env var settings
from env generators or configuration files do not accumulate, but
dynamic API changes are kept around.
Note that this change is not entirely transparent to users: if the user
first uses "set-environment" to override a transient variable, and then
uses "unset-environment" to unset it again things will revert to the
original transient variable now, while previously the variable was fully
removed. This change in behaviour should not matter too much though I
figure.
Fixes: #9972
If WorkingDirectory is on NFS, root might only have the privileges of
nobody and the chdir to the WorkingDirectory might fail, even if the
user running the service would have the proper privileges to chdir to
that directory.
Fixes#10568
There is difference between time set by the user and real elapsed time because of accuracy feature.
If you change the system date(or time) between these times, the timer drops.
You can easily reproduce it with the following command.
-----------------------------------------------------------
$ systemd-run --on-active=3s ls; sleep 3; date -s "`date`"
-----------------------------------------------------------
In the following command, the problem is rarely reproduced. But it exists.
---------------------------------------------------------------------------------------------
$ systemd-run --on-active=3s --timer-property=AccuracySec=1us ls ; sleep 1; date -s "`date`"
---------------------------------------------------------------------------------------------
Note : Global AccuracySec value.
----------------------------------------------------------------------
$ cat /etc/systemd/system.conf
DefaultTimerAccuracySec=1min
----------------------------------------------------------------------
If unit_deserialize() fails (because one read line is overly long), it returns
an error and we would have assumed that the next read would point to the next
unit to deserialize.
But instead unit_deserialize() can leave the file offset in the middle of a
line.
Therefore we need to ignore and skip the current unit in this case too.
While at it, move unit deserialization in a dedicated functions. That should
make the code easier to read.
That way we can pin a specific inode and analyze it and manipulate it
without it being swapped out beneath our hands.
Fixes a vulnerability originally found by Jann Horn from Google.
CVE-2018-15687
LP: #1796692https://bugzilla.redhat.com/show_bug.cgi?id=1639076
When we start a service process we pass the selected watchdog timeout to
it with the $WATCHDOG_USEC environment variable. If the unit file is
reconfigured later, we need to make sure to continue to honour the
original timeout, i.e. watch $WATCHDOG_USEC was set to, otherwise we'll
expect the ping at a different time as the service process is sending it
to us.
Hence, whenever we start a unit, save the watchdog timeout, and stick to
that for everything we do.
Fixes: #9467
Let's make sure we always use the right watchdog timeout: when a service
has overwritten it, then stick to it, also for follow-up processes of
the same service.
Let's be more careful with what we serialize: let's ensure we never
serialize strings that are longer than LONG_LINE_MAX, so that we know we
can read them back with read_line(…, LONG_LINE_MAX, …) safely.
In order to implement this all serialization functions are move to
serialize.[ch], and internally will do line size checks. We'd rather
skip a serialization line (with a loud warning) than write an overly
long line out. Of course, this is just a second level protection, after
all the data we serialize shouldn't be this long in the first place.
While we are at it also clean up logging: while serializing make sure to
always log about errors immediately. Also, (void)ify all calls we don't
expect errors in (or catch errors as part of the general
fflush_and_check() at the end.
The predicate function manager_timestamp_shall_serialize() simply says
whether to serialize or not serialize a timestamp, and should make
things a bit easier to read.
This should be much better than fgets(), as we can read substantially
longer lines and overly long lines result in proper errors.
Fixes a vulnerability discovered by Jann Horn at Google.
CVE-2018-15686
LP: #1796402https://bugzilla.redhat.com/show_bug.cgi?id=1639071
"killing" is very UNIX terminology, and not really what this is about.
Let's be more correct and say "send a UNIX signal" for the operation.
Otherwise things are really weird if users call "journalctl --rotate"
from the command line, which internally asks systemd to send SIGUSR2 to
to journald: when german locale is selected this asks the user — roughly
transliterated — whether they want to "eliminate" journald, which is
definitely not the intended meaning.
Don't add an implicit RequiresMountsFor depenency for the
WorkingDirectory of a unit if the "-" character was used to
indicate that "a missing working directory is not considered fatal"
(see systemd.exec(5)). Otherwise systemd might fail the unit
because of missing dependencies.
When journald reaches the maximum number of active streams, it,
basically, starts to decline new connections. On the client
side it can be detected by getting EPIPE and, if the writing
process isn't lucky enough, getting SIGPIPE soon afterwards.
systemd has always ignored EPIPE, which makes it very hard
to keep track of services losing logs. This patch should make
it easier to detect such services by just staring at the logs
carefully.
In case anyone is interested, the following one-liner run as any user
can be used to paralyze all the stream logging on a machine:
for i in {1..4096}; do systemd-cat -t HEY-$i & done
Lennart Poettering