[systemd-devel] [PATCH] Describe handling of an AF_UNIX socket

[Lennart Poettering]

On Wed, 19.06.13 14:59, Łukasz Stelmach (l.stelmach at samsung.com) wrote:

> Describe how to handle an AF_UNIX socket, with Accept set to false,
> received from systemd, upon exit.
> 
> Signed-off-by: Łukasz Stelmach <l.stelmach at samsung.com>
> ---
>  man/systemd.socket.xml |   12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml
> index 6dc847d..f1e7d40 100644
> --- a/man/systemd.socket.xml
> +++ b/man/systemd.socket.xml
> @@ -381,9 +381,15 @@
>                                  performance reasons, it is recommended
>                                  to write new daemons only in a way
>                                  that is suitable for
> -                                <option>Accept=false</option>. This
> -                                option is mostly useful to allow
> -                                daemons designed for usage with
> +                                <option>Accept=false</option>. A daemon
> +                                listening on an AF_UNIX socket may, but does not need to, call
> +                                <citerefentry><refentrytitle>close</refentrytitle><manvolnum>2</manvolnum></citerefentry>
> +                                or
> +                                <citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>2</manvolnum></citerefentry>
> +                                on the received socket before exiting. However,
> +                                it must not unlink the socket from a
> +                                filesystem. This option is mostly useful
> +                                to allow daemons designed for usage with

Hmm, calling shutdown() on a listening socket will actually do weird
things from which we cannot recover. Calling shutdown() is fine if you
do it on connection sockets, but not for listening sockets. (or in other
words: it's OK for Accept=yes, but not for Accept=no sockets.

I will update the man page accordingly.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.