[Spice-devel] [PATCH spice-server v2 2/2] stream-device: Create channels before first non-main channel connection

[Christophe Fergeau]

Hey,

I assume the client is not going to show an unwanted window or something
like that?

Looks good to me, Acked-by: Christophe Fergeau <cfergeau at redhat.com>
though maybe people more familiar with the streaming channel will want
to take a look too.

Christophe

On Wed, Mar 07, 2018 at 08:26:16AM +0000, Frediano Ziglio wrote:
> Due to ticket expiration, it is possible that the streaming channels for
> the client are created after the ticket expires. Currently, streaming
> channels are created dynamically when the guest starts streaming to the
> server, which can happen at any time (for instance if you decide to start
> the graphic server manually).
> If the ticket has expired before the streaming channel is created,
> authentication will fail and the client will not be able to connect.
> To avoid this, create the channels when the first main channel connection
> is made. This ensures that client will connect to all streaming channels.
> This could be considered a temporary solution. There may be other
> situations where it would be useful to connect new channels after the
> ticket has expired, but enabling this behavior would require protocol
> changes and a careful analysis of security implications.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/reds-private.h  |  1 +
>  server/reds.c          | 22 ++++++++++++++++++++++
>  server/stream-device.c |  6 +++---
>  server/stream-device.h |  1 +
>  4 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/server/reds-private.h b/server/reds-private.h
> index adc48ba5..920edc5c 100644
> --- a/server/reds-private.h
> +++ b/server/reds-private.h
> @@ -117,6 +117,7 @@ struct RedsState {
>      RedStatFile *stat_file;
>  #endif
>      int allow_multiple_clients;
> +    bool late_initialization_done;
>  
>      /* Intermediate state for on going monitors config message from a single
>       * client, being passed to the guest */
> diff --git a/server/reds.c b/server/reds.c
> index 9660476c..73c9ec20 100644
> --- a/server/reds.c
> +++ b/server/reds.c
> @@ -1734,6 +1734,26 @@ static RedClient *reds_get_client(RedsState *reds)
>      return reds->clients->data;
>  }
>  
> +/* Performs late initializations steps.
> + * This should be called when a client connects */
> +static void reds_late_initialization(RedsState *reds)
> +{
> +    RedCharDevice *dev;
> +
> +    // do only once
> +    if (reds->late_initialization_done) {
> +        return;
> +    }
> +
> +    // create stream channels for streaming devices
> +    GLIST_FOREACH(reds->char_devices, RedCharDevice, dev) {
> +        if (IS_STREAM_DEVICE(dev)) {
> +            stream_device_create_channel(STREAM_DEVICE(dev));
> +        }
> +    }
> +    reds->late_initialization_done = true;
> +}
> +
>  static void
>  red_channel_capabilities_init_from_link_message(RedChannelCapabilities *caps,
>                                                  const SpiceLinkMess *link_mess)
> @@ -1769,6 +1789,8 @@ static void reds_handle_main_link(RedsState *reds, RedLinkInfo *link)
>      spice_debug("trace");
>      spice_assert(reds->main_channel);
>  
> +    reds_late_initialization(reds);
> +
>      link_mess = link->link_mess;
>      if (!reds->allow_multiple_clients) {
>          reds_disconnect(reds);
> diff --git a/server/stream-device.c b/server/stream-device.c
> index fd73e784..6cf29d37 100644
> --- a/server/stream-device.c
> +++ b/server/stream-device.c
> @@ -538,8 +538,8 @@ stream_device_finalize(GObject *object)
>      dev->msg_pos = 0;
>  }
>  
> -static void
> -allocate_channels(StreamDevice *dev)
> +void
> +stream_device_create_channel(StreamDevice *dev)
>  {
>      if (dev->stream_channel) {
>          return;
> @@ -600,7 +600,7 @@ stream_device_port_event(RedCharDevice *char_dev, uint8_t event)
>      // reset device and channel on close/open
>      dev->opened = (event == SPICE_PORT_EVENT_OPENED);
>      if (dev->opened) {
> -        allocate_channels(dev);
> +        stream_device_create_channel(dev);
>      }
>      dev->hdr_pos = 0;
>      dev->msg_pos = 0;
> diff --git a/server/stream-device.h b/server/stream-device.h
> index 501629c1..27efaeab 100644
> --- a/server/stream-device.h
> +++ b/server/stream-device.h
> @@ -43,6 +43,7 @@ typedef struct StreamDeviceClass StreamDeviceClass;
>  
>  GType stream_device_get_type(void) G_GNUC_CONST;
>  StreamDevice *stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin);
> +void stream_device_create_channel(StreamDevice *dev);
>  
>  G_END_DECLS
>  
> -- 
> 2.14.3
> 
> _______________________________________________
> Spice-devel mailing list
> Spice-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/spice-devel
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