On Fri, 2016-11-11 at 14:27 +0100, Victor Toso wrote: > From: Victor Toso <me@xxxxxxxxxxxxxx> > > This fixes the situation when VDAgent receives 0 byte message > regarding a file-transfer operation that was terminated in the > previous message. > > This makes the VDAgent to send a STATUS_ERROR after STATUS_SUCCESS to > client. > > Resolves: https://bugs.freedesktop.org/show_bug.cgi?id=97227 > > Signed-off-by: Victor Toso <victortoso@xxxxxxxxxx> > --- > src/channel-main.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/src/channel-main.c b/src/channel-main.c > index 990a06a..72ca712 100644 > --- a/src/channel-main.c > +++ b/src/channel-main.c > @@ -1822,6 +1822,14 @@ static void file_xfer_read_async_cb(GObject > *source_object, > return; > } > > + if (count == 0 && > spice_file_transfer_task_get_total_bytes(xfer_task) > 0) { > + /* If we have sent all payload to the agent, we should not > send 0 bytes > + * as it will cause https://bugs.freedesktop.org/show_bug.cg > i?id=97227. > + * Only when file has 0 bytes of size is when we should send > 0 bytes to > + * agent, see: https://bugzilla.redhat.com/show_bug.cgi?id=1 > 135099 */ > + return; > + } > + > file_xfer_queue_msg_to_agent(channel, > spice_file_transfer_task_get_id(xfer_task), buffer, count); > > if (count == 0 || > spice_file_transfer_task_is_completed(xfer_task)) { > /* on EOF just wait for VD_AGENT_FILE_XFER_STATUS from agent Interesting. I see now though that there's a corner case that could still be slightly problematic: For a zero-length file, we do a read and then this callback is triggered with count == 0. We send that (empty) message to the agent. But say the agent doesn't send back its SUCCESS status very quickly and so the _data_flushed_cb() function intiates another async read. When the async read callback is triggered again, we get another zero-length read. Since the file size is zero, we pass the above conditions and send out a second zero-length data message to the agent. That's the same problem you're trying to fix above for non-zero-length files. It's clearly not as important because it's not at all common to transfer zero-length files, but it's probably still good to handle it. Another semi-related issue: what do we do if a buggy agent never sends a status response? Should we set a timer to cancel the transfer within a certain time after we've sent our last data message if we haven't received a response from the agent yet? Obviously that's not a issue to be solved in this patch, but it's somethign that I was wondering while reviewing the code. Reviewed-by: Jonathon Jongsma <jjongsma@xxxxxxxxxx> _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel