This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
log.h really should only include the bare minimum of other headers, as
it is really pulled into pretty much everything else and already in
itself one of the most basic pieces of code we have.
Let's hence drop inclusion of:
1. sd-id128.h because it's entirely unneeded in current log.h
2. errno.h, dito.
3. sys/signalfd.h which we can replace by a simple struct forward
declaration
4. process-util.h which was needed for getpid_cached() which we now hide
in a funciton log_emergency_level() instead, which nicely abstracts
the details away.
5. sys/socket.h which was needed for struct iovec, but a simple struct
forward declaration suffices for that too.
Ultimately this actually makes our source tree larger (since users of
the functionality above must now include it themselves, log.h won't do
that for them), but I think it helps to untangle our web of includes a
tiny bit.
(Background: I'd like to isolate the generic bits of src/basic/ enough
so that we can do a git submodule import into casync for it)
Let's call getsockopt() in a loop, so that we can deal correctly with
the label changing while we are trying to read it.
(also, while we are at it, let's make sure that there's always one
trailing NUL byte at the end of the buffer, after all SO_PEERSEC has
zero documentation, and multiple implementing backends, hence let's
better be safe than sorry)
Also, drop UID/GID validity checks from getpeercred() as the kernel will
never pass us invalid UID/GID on userns, but the overflow UID/GID
instead. Add a comment about this.
The advantage is that is the name is mispellt, cpp will warn us.
$ git grep -Ee "conf.set\('(HAVE|ENABLE)_" -l|xargs sed -r -i "s/conf.set\('(HAVE|ENABLE)_/conf.set10('\1_/"
$ git grep -Ee '#ifn?def (HAVE|ENABLE)' -l|xargs sed -r -i 's/#ifdef (HAVE|ENABLE)/#if \1/; s/#ifndef (HAVE|ENABLE)/#if ! \1/;'
$ git grep -Ee 'if.*defined\(HAVE' -l|xargs sed -i -r 's/defined\((HAVE_[A-Z0-9_]*)\)/\1/g'
$ git grep -Ee 'if.*defined\(ENABLE' -l|xargs sed -i -r 's/defined\((ENABLE_[A-Z0-9_]*)\)/\1/g'
+ manual changes to meson.build
squash! build-sys: use #if Y instead of #ifdef Y everywhere
v2:
- fix incorrect setting of HAVE_LIBIDN2
The AF_VSOCK address family facilitates guest<->host communication on
VMware and KVM (virtio-vsock). Adding support to systemd allows guest
agents to be launched through .socket unit files. Today guest agents
are stand-alone daemons running inside guests that do not take advantage
of systemd socket activation.
sockaddr_port() either returns a >= 0 port number or a negative errno.
This works for AF_INET and AF_INET6 because port ranges are only 16-bit.
In AF_VSOCK ports are 32-bit so an int cannot represent all port number
and negative errnos. Separate the port and the return code.
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.
As suggested here:
https://github.com/systemd/systemd/pull/4296#issuecomment-251911349
Let's try AF_INET first as socket, but let's fall back to AF_NETLINK, so that
we can use a protocol-independent socket here if possible. This has the benefit
that our code will still work even if AF_INET/AF_INET6 is made unavailable (for
exmple via seccomp), at least on current kernels.
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
Calling recv with a NULL buffer returns EFAULT instead of EOPNOTSUPP on
older kernels (3.14).
Fixes#3407
Signed-off-by: Kai Ruhnau <kai.ruhnau@target-sg.com>
Previously, we'd simply close and reopen the socket file descriptors. This is
problematic however, as we won't transition through the SOCKET_CHOWN state
then, and thus the file ownership won't be correct for the sockets.
Rework the flushing logic, and actually read any queued data from the sockets
for flushing, and accept any queued messages and disconnect them.
This reworks the coredumping logic so that the coredump handler invoked from the kernel only collects runtime data
about the crashed process, and then submits it for processing to a socket-activate coredump service, which extracts a
stacktrace and writes the coredump to disk.
This has a number of benefits: the disk IO and stack trace generation may take a substantial amount of resources, and
hence should better be managed by PID 1, so that resource management applies. This patch uses RuntimeMaxSec=, Nice=, OOMScoreAdjust=
and various sandboxing settings to ensure that the coredump handler doesn't take away unbounded resources from normally
priorized processes.
This logic is also nice since this makes sure the coredump processing and storage is delayed correctly until
/var/systemd/coredump is mounted and writable.
Fixes: #2286
The file /sys/module/ipv6 does not exist in all container
implementations (e.g. Virtuozzo). Using /proc/net/sockstat6
detects IPv6 support reliably in these environments, too.
This file does not exist when the kernel is not compiled with
IPv6 support, or if IPv6 support is disabled, so simply checking
for existence should be a suitable check.
Fixes#2059
Borked since
commit 3ee897d6c2
Author: Lennart Poettering <lennart@poettering.net>
Date: Wed Sep 23 01:00:04 2015 +0200
tree-wide: port more code to use send_one_fd() and receive_one_fd()
because here our fd is not connected and we need to specify
the address.
When constructing the journal filename to store logs from a remote host, remove the port of the tcp connection, as the port will change with every reboot/connection loss between sender/reveiver machines. Having the port in the filename will cause a new journal file to be created for every reboot or connection loss.
For the implementation, a new argument "bool include_port" is added to the getpeername_pretty() function. This is passed to the sockaddr_pretty() function. The value of the include_port argument is set to true in all calls of getpeername_pretty(), except for 2 calls in journal-remote.c, where it is set to false.
Lennart Poettering