This adds a helper call for detaching a DnsServer from a DnsStream if
the latter is the "default" stream of the server.
Also, let's unref the stream in dns_stream_stop() rather than
dns_stream_free(): as soon as our stream is disconnected by stopping
there's really no need to keep it as default stream for the server
around.
Since dns_stream_free() calls dns_stream_stop() we can remove it from
the former.
DnsStream and DnsServer have a symbiotic relationship: one DnsStream is
the current "default" stream of the server (and thus reffed by it), but
each stream also refs the server it is connected to. This cyclic
dependency can result in weird situations: when one is
destroyed/unlinked/stopped it needs to unregister itself from the other,
but doing this will trigger unregistration of the other. Hence, let's
make sure we unregister the stream from the server before destroying it,
to break this cycle.
Most likely fixes: #10725
We register an on_packet() handler anyway, which is called first.
There's hence no need to check in on_stream_complete() again, as it is
already taken by that time.
Let's not name a variable of type ssize_t "r". We usually use "r" for
return values of API calls that return some kind of error as in int.
This creates a lot of confusion if used differently here, which actually
resulted in connect()'s return value being assigned to this mistyped "r"
by accident.
Let's rename the variable "m" hence, and not use it for connect() return
values.
https://bugzilla.redhat.com/show_bug.cgi?id=1656639
Using "--" is a trick that is hard to discover. Let's give users a hint:
$ build/systemctl status -.service
build/systemctl: invalid option -- '.'
Hint: to specify units starting with a dash, use "--":
build/systemctl [OPTIONS...] {COMMAND} -- -.service ...
I use program_invocation_name because that's what getopt seems to use.
"::" is used in the option string so that getopt doesn't complain about
a missing argument in case somebody passes "-." as the argument. After all
"." is not a real option.
If file "/etc/hosts" does not exist, fopen fails and sets errno to ENOENT
("No such file or directory"). So errno should be compared with ENOENT.
This mistake causes test test-resolved-etc-hosts to fail when run on Debian
image built with mkosi.debian included in the repo. The image does not include
"/etc/hosts" file as it is not created by debootstrap, see debootstrap manpage
https://manpages.debian.org/stretch/debootstrap/debootstrap.8.en.html.
Lennart Poettering
Evgeny Vereshchagin
Filipe Brandenburger
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Alexey Bogdanenko
Paweł Szewczyk