Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
As reported in https://github.com/systemd/systemd/issues/38222, we get the
buffer size calculation wrong on 32-bit arm. The reporter suggested checking if
__TIMESIZE == 64, but I think it's better to just use the bigger size in all
cases. The code to guesstimate the buffer size was already tweaked a few times
and apparently it's not easy to get it right. Systemd and glibc might be
compiled with different combinations of __TIMESIZE, so the compile-time check
is not super reliable, and by using the bigger size, we don't depend on the
details of how glibc decided whether to duplicate the struct or not. The cost
is negligible, 16 bytes on stack, so let's do the easy and robust thing.
Solution based on the suggestion by UZver24.
While at it, drop the mock struct definitions. They are only used to calculate
the size, but since the types involved are 8-bit values, there are no alignment
issues and we can just calculate the size directly.
Fixes https://github.com/systemd/systemd/issues/38222.
On Linux, read() on a message queue descriptor returns the message
queue statistics, not the actual message queue data. We need to use
mq_receive() to drain the queues instead.
Fixes a problem where a POSIX message queue socket unit with messages
in the queue at shutdown time could result in a hang on reboot/shutdown.
The header requires struct sockaddr declared. So, otherwise, we need to
include sys/socket.h earlier than linux/vm_sockets.h.
Let's make the header includable at any place.
This is a rework of #24764 by Cristian Rodríguez
<crodriguez@owncloud.com>, which stalled.
Instead of assigning -1 we'll use a macro defined to INT_MAX however.
The cmd(3) man page says about CMSG_DATA():
> The pointer returned cannot be assumed to be suitably aligned for
> accessing arbitrary payload data types. Applications should not cast
> it to a pointer type matching the payload, but should instead use
> memcpy(3) to copy data to or from a suitably declared object.
Hence, if we want to use unaligned data in cmsg, we need to copy it
before use. That's typically important for reading timestamps in
RISCV32, as the time_t is 64bit and size_t is 32bit on the system.
Apparently CMSG_DATA() alignment is very much undefined. Which is quite
an ABI fuck-up, but we need to deal with this. CMSG_TYPED_DATA() already
checks alignment of the specified pointer. Let's also check matching
alignment of the underlying structures, which we already can do at
compile-time.
See: #27241
(This does not fix#27241, but should catch such errors already at
compile-time instead of runtime)
This is a short helper for connecting to AF_UNIX sockets in the file
system. It works around the 108ch limit of sockaddr_un, and supports
"at" style fds.
This doesn't come with a test of its own, but the next patch will add
that.
It does the same stuff, let's use the same codepaths as much as we can.
And while we are at it, let's generate good error codes in case we are
called with unsupported parameters/let's validate stuff more that might
originate from user input.
In general we almost never hit those asserts in production code, so users see
them very rarely, if ever. But either way, we just need something that users
can pass to the developers.
We have quite a few of those asserts, and some have fairly nice messages, but
many are like "WTF?" or "???" or "unexpected something". The error that is
printed includes the file location, and function name. In almost all functions
there's at most one assert, so the function name alone is enough to identify
the failure for a developer. So we don't get much extra from the message, and
we might just as well drop them.
Dropping them makes our code a tiny bit smaller, and most importantly, improves
development experience by making it easy to insert such an assert in the code
without thinking how to phrase the argument.
[59/1551] Compiling C object src/basic/libbasic.a.p/socket-util.c.o
../src/basic/socket-util.c: In function ‘socket_get_mtu’:
../src/basic/socket-util.c:1393:16: warning: ‘mtu’ may be used uninitialized in this function [-Wmaybe-uninitialized]
1393 | *ret = (size_t) mtu;
| ^~~~~~~~~~~~