Servers that recognize this special report then stop streaming (sending regular screen updates instead) while older ones essentially ignore it. Signed-off-by: Francois Gouget <fgouget@xxxxxxxxxxxxxxx> --- This patchset is based on Victor Toso's idea [1] of using the stream reports to tell the server that, despite expectations, the client cannot handle a given stream. You'll notice that this patch does not directly check for create_xxx_decoder() errors. Instead it relies on the previous patchset [2] deleting broken streams so that the following messages will run into an unknown stream. Of course this could already happen in case of a malicious server sending garbage to the client. So this patchset is quite independent from the previous one. I don't know what the consequences of receiving an unknown message would be for the server so I chose to hook into the display_handle_stream_activate_report() as that's where we get notified that the server supports the stream reports. Maybe we should send such an error anywhere we receive a message with an unknown stream_id. There's really no reason for that to happen in those other places though, except if the server does not recognize the initial error stream report and continues streaming. In that case sending more error messages won't do any good. So sending an error in just this one place may make more sense. We could also add an extra cap to identify servers that recognize this special type or stream report. But is it really worth it? [1] https://lists.freedesktop.org/archives/spice-devel/2016-August/031101.html [2] https://lists.freedesktop.org/archives/spice-devel/2016-August/031282.html src/channel-display.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/src/channel-display.c b/src/channel-display.c index 709b3d2..3898f0a 100644 --- a/src/channel-display.c +++ b/src/channel-display.c @@ -1530,10 +1530,28 @@ static void display_handle_stream_activate_report(SpiceChannel *channel, SpiceMs g_return_if_fail(c != NULL); g_return_if_fail(c->streams != NULL); - g_return_if_fail(c->nstreams > op->stream_id); - st = c->streams[op->stream_id]; - g_return_if_fail(st != NULL); + st = op->stream_id < c->nstreams ? c->streams[op->stream_id] : NULL; + if (st == NULL) { + SpiceMsgcDisplayStreamReport report; + SpiceMsgOut *msg; + + /* Send a special stream report to indicate there is no such stream */ + spice_printerr("notify the server that stream %u does not exist", op->stream_id); + report.stream_id = op->stream_id; + report.unique_id = op->unique_id; + report.start_frame_mm_time = 0; + report.end_frame_mm_time = 0; + report.num_frames = 0; + report.num_drops = UINT_MAX; + report.last_frame_delay = 0; + report.audio_delay = 0; + + msg = spice_msg_out_new(SPICE_CHANNEL(channel), SPICE_MSGC_DISPLAY_STREAM_REPORT); + msg->marshallers->msgc_display_stream_report(msg->marshaller, &report); + spice_msg_out_send(msg); + return; + } st->report_is_active = TRUE; st->report_id = op->unique_id; -- 2.8.1 _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel