This is preparation for #28891, which adds a bunch more helpers around
"struct iovec", at which point this really deserves its own .c/.h file.
The idea is that we sooner or later can consider "struct iovec" as an
entirely generic mechanism to reference some binary blob, and is the
go-to type for this purpose whenever we need one.
IN C23, thread_local is a reserved keyword and we shall therefore
do nothing to redefine it. glibc has it defined for older standard
version with the right conditions.
v2 by Yu Watanabe:
Move the definition to missing_threads.h like the way we define e.g.
missing syscalls or missing definitions, and include it by the users.
Co-authored-by: Yu Watanabe <watanabe.yu+github@gmail.com>
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
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.
DNS_HOSTNAME_MAX is used by sd-resolve, but it was defined in
src/shared/dns-domain.h. The library libsystemd should be independent
of source files under src/shared.
This really doesn't matter given that AF_xyz and PF_xyz are equivalent
in all ways, but we almost always use AF_xyz, hence stick to it
universally and convert the remaining PF_ to AF_
Found by inspecting results of running this small program:
int main(int argc, const char **argv) {
for (int i = 1; i < argc; i++) {
FILE *f;
char line[1024], prev[1024], *r;
int lineno;
prev[0] = '\0';
lineno = 1;
f = fopen(argv[i], "r");
if (!f)
exit(1);
do {
r = fgets(line, sizeof(line), f);
if (!r)
break;
if (strcmp(line, prev) == 0)
printf("%s:%d: error: dup %s", argv[i], lineno, line);
lineno++;
strcpy(prev, line);
} while (!feof(f));
fclose(f);
}
}
Continuation of a3ebe5eb62:
in other places we sometimes use assert_se(), and sometimes normal error
handling. sigfillset and sigaddset can only fail if mask is NULL (which cannot
happen if we are passing in a reference), or if the signal number is invalid
(which really shouldn't happen when we are using a constant like SIGCHLD. If
SIGCHLD is invalid, we have a bigger problem). So let's simplify things and
always use assert_se() in those cases.
In sigset_add_many() we could conceivably pass an invalid signal, so let's keep
normal error handling here. The caller can do assert_se() around the
sigprocmask_many() call if appropriate.
'>= 0' is used for consistency with the rest of the codebase.
From WordNet (r) 3.0 (2006) [wn]:
time-out
n 1: a brief suspension of play; "each team has two time-outs left"
From The Free On-line Dictionary of Computing (18 March 2015) [foldoc]:
timeout
A period of time after which an error condition is raised if
some event has not occured. A common example is sending a
message. If the receiver does not acknowledge the message
within some preset timeout period, a transmission error is
assumed to have occured.
When a nested struct is initialized by structured initializer, then
padding space is not cleared by zero. So, before setting values,
this makes explicitly set zero including padding.
This fixes the following false positive warning by valgrind:
```
==492== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==492== at 0x56D0CF7: sendmsg (in /usr/lib64/libpthread-2.27.so)
==492== by 0x4FDD3C5: sd_resolve_getaddrinfo (sd-resolve.c:975)
==492== by 0x110B9E: manager_connect (timesyncd-manager.c:879)
==492== by 0x10B729: main (timesyncd.c:165)
==492== Address 0x1fff0008f1 is on thread 1's stack
==492== in frame #1, created by sd_resolve_getaddrinfo (sd-resolve.c:928)
==492==
```
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Let's tweak the assignment of errors a bit, and automatically abs()
errnos, similar to how log_error_errno() and friends does it.
Macros are fine to use, but regular functions usually preferable if
there's no reason to use macros, because they avoid multiple evaluation
and suchlike. Hence, let's just use a regular funciton for assigning
errors, instead of macros.
Follow-up for #8993
The protocol is that a string is serialized with the nul byte at the end, and
the terminator is included in length. We'd call strndup with offset 0, length
len1-1, and then a second time with offset len1, length len2-1, so in the end
the check was off by one. But let's require the terminating nul too, even if
we don't access it.
CID #1383035.
This is external data, even if trusted. We should not assert on it, but verify
and return proper error instead, which assert_return does. In particular,
write(2) says that a partial write could occur when interupted by a signal.
When compiled with asserts disabled, we could access memory outside of the
allocated buffer.
CID #1237671.
Follow-up for 1a96c8e1cc.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This adds some paranoia code that moves some of the fds we allocate for
longer periods of times to fds > 2 if they are allocated below this
boundary. This is a paranoid safety thing, in order to avoid that
external code might end up erroneously use our fds under the assumption
they were valid stdin/stdout/stderr. Think: some app closes
stdin/stdout/stderr and then invokes 'fprintf(stderr, …' which causes
writes on our fds.
This both adds the helper to do the moving as well as ports over a
number of users to this new logic. Since we don't want to litter all our
code with invocations of this I tried to strictly focus on fds we keep
open for long periods of times only and only in code that is frequently
loaded into foreign programs (under the assumptions that in our own
codebase we are smart enough to always keep stdin/stdout/stderr
allocated to avoid this pitfall). Specifically this means all code used
by NSS and our sd-xyz API:
1. our logging APIs
2. sd-event
3. sd-bus
4. sd-resolve
5. sd-netlink
This changed was inspired by this:
https://github.com/systemd/systemd/issues/8075#issuecomment-363689755
This shows that apparently IRL there are programs that do close
stdin/stdout/stderr, and we should accomodate for that.
Note that this won't fix any bugs, this just makes sure that buggy
programs are less likely to interfere with out own code.
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)
Yu Watanabe
Lennart Poettering
David Tardon
Cristian RodríguezandYu Watanabe
Zbigniew Jędrzejewski-Szmek
Frantisek Sumsal
fangxiuning
Topi Miettinen