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

[Marc-André Lureau]

Hi

On Thu, Oct 5, 2017 at 5:40 PM, Daniel P. Berrange <address@hidden> wrote:
> 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 ?

the mixedCase, let's stick to lower_case for variables.

>
>
> Regards,
> Daniel
> --
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-- 
Marc-André Lureau