[Spice-devel] [PATCH spice 3/3] reds: Cancel unexpected xfer messages

[Pavel Grunt]

Inform client that transfer will not work, instead of only
dropping the agent messages.

The file transfer messages can be disabled using qemu cli option:
 "disable-agent-file-xfer"

Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=1373725

Signed-off-by: Pavel Grunt <pgrunt at redhat.com>
---
Can be extended to use a detailed status message introduced recently in protocol
---
 server/reds.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/server/reds.c b/server/reds.c
index 8abeb3fbd..38d34c827 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -1110,6 +1110,39 @@ static void reds_on_main_agent_monitors_config(RedsState *reds, const void *mess
     reds_client_monitors_config_cleanup(reds);
 }
 
+static void agent_data_free(uint8_t *data, void *opaque G_GNUC_UNUSED)
+{
+    free(data);
+}
+
+/*
+ * Inform client about discarded file transfer
+ * https://bugzilla.redhat.com/show_bug.cgi?id=1373725 
+ */
+static void agent_xfer_error(MainChannelClient *mcc, const VDAgentMessage *message)
+{
+    VDAgentMessage *xfer_msg;
+    VDAgentFileXferStatusMessage *xfer_status;
+    size_t len;
+ 
+    if (message->type < VD_AGENT_FILE_XFER_START || message->type > VD_AGENT_FILE_XFER_DATA) {
+        return;
+    }
+
+    len = sizeof(VDAgentMessage) + sizeof(VDAgentFileXferStatusMessage);
+    xfer_msg = spice_malloc0(len);
+    xfer_msg->protocol = VD_AGENT_PROTOCOL;
+    xfer_msg->type = VD_AGENT_FILE_XFER_STATUS;
+    xfer_msg->size = sizeof(VDAgentFileXferStatusMessage);
+    xfer_status = (VDAgentFileXferStatusMessage *) xfer_msg->data;
+    xfer_status->id = *((uint32_t *) message->data);
+    xfer_status->result = VD_AGENT_FILE_XFER_STATUS_ERROR;
+
+    spice_debug("canceling file transfer %u", xfer_status->id);
+
+    main_channel_client_push_agent_data(mcc, (uint8_t *) xfer_msg, len, agent_data_free, NULL);
+}
+
 void reds_on_main_agent_data(RedsState *reds, MainChannelClient *mcc, const void *message,
                              size_t size)
 {
@@ -1123,6 +1156,7 @@ void reds_on_main_agent_data(RedsState *reds, MainChannelClient *mcc, const void
     case AGENT_MSG_FILTER_OK:
         break;
     case AGENT_MSG_FILTER_DISCARD:
+        agent_xfer_error(mcc, message);
         return;
     case AGENT_MSG_FILTER_MONITORS_CONFIG:
         reds_on_main_agent_monitors_config(reds, message, size);
-- 
2.13.0