sd_journal_stream_fd() does not return the same file descriptor across
different calls. It can't possibly do so, because the file descriptor
is created using certain parameters passed by the caller.
Also the implementation clearly isn't doing this, it's just connecting
to a unix socket.
It opens exactly one file descriptor, and does not close it unless there
is a write failure. Nothing like "temporarily multiple file descriptors
may be open".
These restrictions are implied by systemd options used for
systemd-udevd.service, i.e. MountFlags=slave and
IPAddressDeny=any. However, there are users out there getting tripped by
this, so let's make things clear in the man page so the actual
restrictions we implement by default have better visibility.
Follow-up for e79eabdb1b. There was an
apparent contradiction:
man/systemd.unit says for Requires=:
Besides, with or without specifying After=, this unit will be deactivated
if one of the other units get deactivated.
Also, some unit types may deactivate on their own (for example, a service
process may decide to exit cleanly, or a device may be unplugged by the
user), which is not propagated to units having a Requires= dependency.
Fixes#7870.
Let's be more restrictive when validating PID files and MAINPID=
messages: don't accept PIDs that make no sense, and if the configuration
source is not trusted, don't accept out-of-cgroup PIDs. A configuratin
source is considered trusted when the PID file is owned by root, or the
message was received from root.
This should lock things down a bit, in case service authors write out
PID files from unprivileged code or use NotifyAccess=all with
unprivileged code. Note that doing so was always problematic, just now
it's a bit less problematic.
When we open the PID file we'll now use the CHASE_SAFE chase_symlinks()
logic, to ensure that we won't follow an unpriviled-owned symlink to a
privileged-owned file thinking this was a valid privileged PID file,
even though it really isn't.
Fixes: #6632
The new --uid= switch allows selecting the UID from which the
notificaiton messages shall originate.
This is primarily useful for testing purposes, but might have other
uses.
Nowadays people use systemd on many different architectures, so we
shouldn't presuppose that they are using amd64. debootstrap defaults
to the native architecture and this should be good enough.
This adds a simple condition/assert/match to the service manager, to
udev's .link handling and to networkd, for matching the kernel version
string.
In this version we only do fnmatch() based globbing, but we might want
to extend that to version comparisons later on, if we like, by slightly
extending the syntax with ">=", "<=", ">", "<" and "==" expressions.
Follow-up to @poettering’s comments in #7723:
- Slightly expand on the difference between using tmpfiles.d and service
directives
- Mention CacheDirectory=
- Mention LogsDirectory=
- Abbreviate and unify some later descriptions
ConfigDirectory= is not mentioned, since it does not support the
functionality mentioned in the manpage which tmpfiles.d provides:
copying or symlinking default configuration from /usr/share/factory. And
the user package variable file locations don’t mention the directives
because in user units the service can always create the directories
itself (whereas in system units lesser-privileged services lack
permission to create them).
Zbigniew Jędrzejewski-Szmek
Alan Jenkins
Yu Watanabe
Susant Sahani
Michal Sekletar
John Lin
Shawn Landden
Дилян Палаузов
Lennart Poettering
Susant Sahani
Jörg Thalheim
Patrik Flykt
nulsoh
Lucas Werkmeister