We use this at various places, let's unify this in one global constant.
This changes flags in crash-handler.c in a tiny irrelevant way: we ask
syscalls to be continued on signal arrival, which we previously didn't.
But that shouldn't change anything, the only thing we'll do in the
relevant process is call raise(), and that's it, hence there definitely
are no syscalls to restart or not to restart.
- introduce or rename usual enum values _MAX and _INVALID,
- introduce and use string table lookup functions,
- split out implementation of get_color_mode() to _impl(),
- add tests for get_color_mode().
Doing this in reset_terminal_fd() is a bit too invasive, see
https://github.com/systemd/systemd/pull/32406#issuecomment-2070923583.
Let's only do this for /dev/console so that we work around weird firmwares
disabling line-wrapping, but avoid messing too much with other things.
While we're at it, let's handle more than just line wrapping, and do a
more general reset of stuff to get the terminal into a sane state.
The qemu seabios firmware disables serial console line wrapping. Let's
make sure we re-enable it again when we reset a terminal to some sane
defaults.
To avoid potentially blocking on writing to the terminal, we put it
in nonblocking mode and add a timeout of 50ms.
We shouldn't try to use any ANSI escape sequences if TERM=dumb.
Also, the "\r\n" we output can get interpreted as a double newline
(for example by Github Actions), so let's output just "\n" when
TERM=dumb to clean up the CI logs.
Currently scan_background_color_response only accepts BEL (\x07) to end
a response, however some terminals (namely kitty in my case) will reply
with the string terminator (ST - https://en.wikipedia.org/wiki/ANSI_escape_code).
This commit changes the behaviour to now accept either ending.
Currently the return value 0 is not checked for, this indicates a
timeout and should be handled to prevent doing a blocking read on a file
descriptor with no data ready.
Let's disable ECHOPRT for terminals we reset.
The feature only really makes sense for hardcopy terminals and we sure
as shit don't talk to one of those. It has the effect that when line
editing is on and you hit backspace it outputs "\" followed by the
removed character. This never makes sense on a TTY that can just erase
the character.
Hence turn of this flag.
We have carried this flag along for about forever, but it doesn't really
make sense. I guess we mostly tested the terminal reset stuff for output
only, not for input.
This change is in particular useful for tools such as
"systemd-firstboot" which interactively ask questions on the console,
and where line editing should really work.
Sometimes it makes sense to hard kill a client if we die. Let's hence
add a third FORK_DEATHSIG flag for this purpose: FORK_DEATHSIG_SIGKILL.
To make things less confusing this also renames FORK_DEATHSIG to
FORK_DEATHSIG_SIGTERM to make clear it sends SIGTERM. We already had
FORK_DEATHSIG_SIGINT, hence this makes things nicely symmetric.
A bunch of users are switched over for FORK_DEATHSIG_SIGKILL where we
know it's safe to abort things abruptly. This should make some kernel
cases more robust, since we cannot get confused by signal masks or such.
While we are at it, also fix a bunch of bugs where we didn't take
FORK_DEATHSIG_SIGINT into account in safe_fork()
We use it for more than just pipe() arrays. For example also for
socketpair(). Hence let's give it a generic name.
Also add EBADF_TRIPLET to mirror this for things like
stdin/stdout/stderr arrays, which we use a bunch of times.
We use usec_t for storing time value, which is 64bit.
However, usleep() takes useconds_t that is (typically?) 32bit.
Also, usleep() may only support the range [0, 1000000].
This introduce usleep_safe() which takes usec_t.
If we're connected to /dev/null, we're likely going to be writing
colors to something that's not stdout/stderr, so let's fall back to
checking TERM if that's the case.
-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.
reset_terminal_fd sets certain minimum required terminal attributes
that systemd relies on.
One of those attributes is `ONLCR` which ensures that when a new line
is sent to the terminal, that the cursor not only moves to the next
line, but also moves to the very beginning of that line.
In order for `ONLCR` to work, the terminal needs to perform output
post-processing. That requires an additional attribute, `OPOST`,
which reset_terminal_fd currently fails to ensure is set.
In most cases `OPOST` (and `ONLCR` actually) are both set anyway, so
it's not an issue, but it could be a problem if, e.g., the terminal was
put in raw mode by a program and the program unexpectedly died before
restoring settings.
This commit ensures when `ONLCR` is set `OPOST` is set too, which is
the only thing that really makes sense to do.
The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
We now have a local implementation in string-util-fundamental.c, but
it's useful at a lot of other places, hence let's give it a more
expressive name and share it across the tree.
Follow-up for: 8d9156660d
Fixup for a5efbf468c: if $COLORTERM was set, we'd
unconditionally turn on colors, which is unexpected and wrong. It even breaks
our own tests when executed in gnome-terminal.
No actual code changes, just splitting out of some dev_t handling
related calls from stat-util.[ch], they are quite a number already, and
deserve their own module now I think.
Also, try to settle on the name "devnum" as the name for the concept,
instead of "devno" or "dev" or "devid". "devnum" is the name exported in
udev APIs, hence probably best to stick to that. (this just renames a
few symbols to "devum", local variables are left untouched, to make the
patch not too invasive)
No actual code changes.
fd_duplicate_data_fd() is renamed to copy_data_fd(). This makes
the two functions have nicely similar names.
Now fd-util.[ch] is again about low-level file descriptor manipulations.
copy_data_fd() is a complex function that internally wraps the other
functions in copy.c. I want to move copy.c and the whole cluster of
related code from basic/ to shared/ later on, and this is a preparatory
step for that.
Hardcoding major numbers sucks. And we generally don't do it, except
when determining whether something is a PTY. Thing though is that we
don't actually need to do that here either, hence don#t.
Lennart Poettering
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Sam Leonard
Mike Yuan
OMOJOLA JOSHUA
Ray Strode
Sonali Srivastava