Re: [Qemu-devel] [PATCH] char: don't skip client cleanup if 'connected' flag is unset

[Daniel P. Berrange]

On Thu, Oct 05, 2017 at 05:35:39PM +0200, Marc-André Lureau wrote:
> Hi
> 
> On Thu, Oct 5, 2017 at 5:28 PM, Daniel P. Berrange <address@hidden> wrote:
> > The tcp_chr_free_connection & tcp_chr_disconnect methods both
> > skip all of their cleanup work unless the 's->connected' flag
> > is set.  This flag is set when the incoming client connection
> > is ready to use. Crucially this is *after* the TLS handshake
> > has been completed. So if the TLS handshake fails and we try
> > to cleanup the failed client, all the cleanup is skipped as
> > 's->connected' is still false.
> >
> > The only important thing that should be skipped in this case
> > is sending of the CHR_EVENT_CLOSED, because we never got as
> > far as sending the corresponding CHR_EVENT_OPENED. Every other
> > bit of cleanup can be robust against being called even when
> > s->connected is false.
> >
> > Signed-off-by: Daniel P. Berrange <address@hidden>
> > ---
> >  chardev/char-socket.c | 31 +++++++++++++++++--------------
> >  1 file changed, 17 insertions(+), 14 deletions(-)
> >
> > diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> > index e65148fe97..a34d4d72c2 100644
> > --- a/chardev/char-socket.c
> > +++ b/chardev/char-socket.c
> > @@ -332,10 +332,6 @@ static void tcp_chr_free_connection(Chardev *chr)
> >      SocketChardev *s = SOCKET_CHARDEV(chr);
> >      int i;
> >
> > -    if (!s->connected) {
> > -        return;
> > -    }
> > -
> >      if (s->read_msgfds_num) {
> >          for (i = 0; i < s->read_msgfds_num; i++) {
> >              close(s->read_msgfds[i]);
> > @@ -347,10 +343,14 @@ static void tcp_chr_free_connection(Chardev *chr)
> >
> >      tcp_set_msgfds(chr, NULL, 0);
> >      remove_fd_in_watch(chr);
> > -    object_unref(OBJECT(s->sioc));
> > -    s->sioc = NULL;
> > -    object_unref(OBJECT(s->ioc));
> > -    s->ioc = NULL;
> > +    if (s->sioc) {
> > +        object_unref(OBJECT(s->sioc));
> > +        s->sioc = NULL;
> > +    }
> > +    if (s->ioc) {
> > +        object_unref(OBJECT(s->ioc));
> > +        s->ioc = NULL;
> > +    }
> 
> object_unref() and OBJECT() are null-safe.
> 
> >      g_free(chr->filename);
> >      chr->filename = NULL;
> >      s->connected = 0;
> > @@ -394,22 +394,25 @@ static void 
> > update_disconnected_filename(SocketChardev *s)
> >                                           s->is_listen, s->is_telnet);
> >  }
> >
> > +/* NB may be called even if tcp_chr_connect has not been
> > + * reached, due to TLS or telnet initialization failure,
> > + * so can *not* assume s->connected == true
> > + */
> >  static void tcp_chr_disconnect(Chardev *chr)
> >  {
> >      SocketChardev *s = SOCKET_CHARDEV(chr);
> > -
> > -    if (!s->connected) {
> > -        return;
> > -    }
> > +    bool emitClose = s->connected;
> 
> ewh, which code style do you pick today? :)

Which bit don't you like ?  The 'bool' or the camelCase, or both ?


Regards,
Daniel
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