Re: [RFC PATCH v1 03/26] char-socket: fix the client mode when created through QMP

["Adalbert Lazăr" <alazar@bitdefender.com>]

On Wed, 15 Apr 2020 16:11:14 +0200, Markus Armbruster <armbru@redhat.com> wrote:
> Adalbert Lazãr <alazar@bitdefender.com> writes:
> 
> > On Wed, 15 Apr 2020 12:37:34 +0200, Marc-André Lureau <marcandre.lureau@gmail.com> wrote:
> >> Hi
> >> 
> >> On Wed, Apr 15, 2020 at 3:00 AM Adalbert Lazăr <alazar@bitdefender.com> wrote:
> >> >
> >> > qmp_chardev_open_socket() ignores the absence of the 'server' argument
> >> > and always switches to listen/server mode.
> >> >
> >> > CC: "Marc-André Lureau" <marcandre.lureau@redhat.com>
> >> > CC: Paolo Bonzini <pbonzini@redhat.com>
> >> > Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
> >> > ---
> >> >  chardev/char-socket.c | 2 +-
> >> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >> >
> >> > diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> >> > index 9b2deb0125..fd0106ab85 100644
> >> > --- a/chardev/char-socket.c
> >> > +++ b/chardev/char-socket.c
> >> > @@ -1310,7 +1310,7 @@ static void qmp_chardev_open_socket(Chardev *chr,
> >> >      SocketChardev *s = SOCKET_CHARDEV(chr);
> >> >      ChardevSocket *sock = backend->u.socket.data;
> >> >      bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
> >> > -    bool is_listen      = sock->has_server  ? sock->server  : true;
> >> > +    bool is_listen      = sock->has_server  ? sock->server  : false;
> >> 
> >> I don't understand what you mean. It defaults to server mode. We can't
> >> change that.
> >
> > First of all, thanks for your comments.
> >
> > I understand that a chardev socket is either in client mode or in server
> > mode.  If the 'server' parameter is not used, the socket is put in client
> > mode. At least this is the behavior when the socket is created by parsing
> > the command line. But, when created through QMP, without the 'server' parameter,
> > the socket is put in server mode.
> >
> > Until this moment, I did not think that we can use "server=no" through QMP :))
> 
> Start here:
> 
>     $ socat "READLINE,history=$HOME/.qmp_history,prompt=QMP>" UNIX-CONNECT:$HOME/work/images/test-qmp 
>     {"QMP": {"version": {"qemu": {"micro": 92, "minor": 2, "major": 4}, "package": "v5.0.0-rc2-30-g25b0509e28"}, "capabilities": ["oob"]}}
>     QMP>{"execute": "qmp_capabilities"}
>     {"return": {}}
>     QMP>{"execute":"chardev-add", "arguments": {"id":"foo", "backend": {"type": "socket", "data": {"addr": {"type": "inet", "data": {"host": "0.0.0.0", "port": "2445"}}, "server": false}}}}
>     {"error": {"class": "GenericError", "desc": "Failed to connect socket: Connection refused"}}
> 

Thank you, Markus.

I wanted to say that while I was writing the reply, I had an aha! moment and I was
amused that I have not thought to use server=no/false and I used the wrong verb tense.