Re: [Qemu-devel] [PATCH] io: fix handling of EOF / error conditions in websock GSource

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Daniel,

On 2/20/19 7:25 PM, Daniel P. Berrangé wrote:
> We were never reporting the G_IO_HUP event when an end of file was hit
> on the websocket channel.
> 
> We also ddn't report G_IO_ERR when we hit a fatal error processing the

"didn't report"

> websocket protocol.
> 
> The latter in particular meant that the chardev code would not notice
> when an eof/error was encountered on the websocket channel, unless the
> guest OS happened to trigger a write operation.
> 
> This meant that once the first client had quit, the chardev would never
> listen to accept a new client.
> 
> Fixes launchpad bug 1816819
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  io/channel-websock.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/io/channel-websock.c b/io/channel-websock.c
> index dc43dc6bb9..fc4c3dcaa5 100644
> --- a/io/channel-websock.c
> +++ b/io/channel-websock.c
> @@ -1225,12 +1225,18 @@ qio_channel_websock_source_check(GSource *source)
>      QIOChannelWebsockSource *wsource = (QIOChannelWebsockSource *)source;
>      GIOCondition cond = 0;
>  
> -    if (wsource->wioc->rawinput.offset || wsource->wioc->io_eof) {
> +    if (wsource->wioc->rawinput.offset) {
>          cond |= G_IO_IN;
>      }
>      if (wsource->wioc->encoutput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER) {
>          cond |= G_IO_OUT;
>      }
> +    if (wsource->wioc->io_eof) {
> +        cond |= G_IO_IN | G_IO_HUP;

Shouldn't this be:

           cond |= G_IO_HUP;

> +    }
> +    if (wsource->wioc->io_err) {
> +        cond |= G_IO_IN | G_IO_ERR;

Ditto:

           cond |= G_IO_ERR;

> +    }
>  
>      return cond & wsource->condition;
>  }
>