[libvirt] [PATCH] remote: fix systemd IP socket activation with virtproxyd

[Erik Skultety]

On Tue, Sep 24, 2019 at 04:07:17PM +0100, Daniel P. Berrangé wrote:
> We recently forbid the use of --listen with socket activation:
>
>   commit 3a6a725b8f575890ee6c151ad1f46ea0ceea1f3b
>   Author: Daniel P. Berrangé <berrange at redhat.com>
>   Date:   Thu Aug 22 14:52:16 2019 +0100
>
>       remote: forbid the --listen arg when systemd socket activation
>
> In this change we forgot that virtproxyd doesn't have a --listen
> parameter, and instead behaves as if it was always present. Thus
> when systemd socket activation is present, we must disable this
> built-in default
>
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>  src/remote/remote_daemon.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/src/remote/remote_daemon.c b/src/remote/remote_daemon.c
> index 7195ac9218..43409edd24 100644
> --- a/src/remote/remote_daemon.c
> +++ b/src/remote/remote_daemon.c
> @@ -423,11 +423,20 @@ daemonSetupNetworking(virNetServerPtr srv,
>          return -1;
>
>  #ifdef WITH_IP
> +# ifdef (LIBVIRTD

^fails to compile:
s/(//

>      if (act && ipsock) {
>          VIR_ERROR(_("--listen parameter not permitted with systemd activation "
>                      "sockets, see 'man libvirtd' for further guidance"));
>          return -1;
>      }
> +# else /* ! LIBVIRTD */
> +    /* We don't have a --listen arg with virtproxyd, we're just
> +     * hardcoded to assume --listen. Thus with systemd we must
> +     * change that default
> +     */
> +    if (act)
> +        ipsock = 0;

I'm a bit confused with this bit wrt to what actually happens later in the
code. Basically this @ipsock is only relevant up until the point where we start
registering services listening for traffic e.g.virNetServerAddServiceTCP (this
is one is easier as an example). If I look at the condition:

if (((ipsock && config->listen_tcp) || act) ...

why does it even matter that we clear ipsock when socket activation is enabled?
The condition is true regardless of @ipsock and it's also not populated further
into the function being called unlike @act, so this bit is making me confused,
so what exactly is happening if we don't clear @ipsock with virtproxyd?

Erik