[Spice-devel] [RFC PATCH spice-server] stream-device: Create channels before first not main connection

[Frediano Ziglio]

Due to ticket expiration is possible that the streaming
channels for the client are created after the ticket expires.
This would cause the client to not be able to connect back
to a new streaming channel.
To avoid this create the channels when the first main channel
connection is made. This make sure that client will connect
to all streaming channels.
This can be considered a temporary solution, connecting back
to the VM is helpful in different situations however this
requires some protocol changes and different security considerations.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/char-device.h   |  1 +
 server/reds-private.h  |  1 +
 server/reds.c          | 20 ++++++++++++++++++++
 server/stream-device.c | 11 +++++++++++
 4 files changed, 33 insertions(+)

diff --git a/server/char-device.h b/server/char-device.h
index 54a1ef93..a9634383 100644
--- a/server/char-device.h
+++ b/server/char-device.h
@@ -237,6 +237,7 @@ RedCharDevice *spicevmc_device_connect(RedsState *reds,
 void spicevmc_device_disconnect(RedsState *reds,
                                 SpiceCharDeviceInstance *char_device);
 RedCharDevice *stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin);
+void stream_device_create_channel(RedCharDevice *dev);
 
 SpiceCharDeviceInterface *spice_char_device_get_interface(SpiceCharDeviceInstance *instance);
 
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 a31ed4e9..30243f47 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -1733,6 +1733,24 @@ 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) {
+        stream_device_create_channel(dev);
+    }
+    reds->late_initialization_done = true;
+}
+
 static void
 red_channel_capabilities_init_from_link_message(RedChannelCapabilities *caps,
                                                 const SpiceLinkMess *link_mess)
@@ -1768,6 +1786,8 @@ 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 b206b116..9298d16e 100644
--- a/server/stream-device.c
+++ b/server/stream-device.c
@@ -32,6 +32,8 @@
     (G_TYPE_CHECK_INSTANCE_CAST((obj), TYPE_STREAM_DEVICE, StreamDevice))
 #define STREAM_DEVICE_CLASS(klass) \
     (G_TYPE_CHECK_CLASS_CAST((klass), TYPE_STREAM_DEVICE, StreamDeviceClass))
+#define IS_STREAM_DEVICE(obj) \
+    (G_TYPE_CHECK_INSTANCE_TYPE((obj), TYPE_STREAM_DEVICE))
 #define STREAM_DEVICE_GET_CLASS(obj) \
     (G_TYPE_INSTANCE_GET_CLASS((obj), TYPE_STREAM_DEVICE, StreamDeviceClass))
 
@@ -70,6 +72,7 @@ static StreamDevice *stream_device_new(SpiceCharDeviceInstance *sin, RedsState *
 G_DEFINE_TYPE(StreamDevice, stream_device, RED_TYPE_CHAR_DEVICE)
 
 static void char_device_set_state(RedCharDevice *char_dev, int state);
+static void allocate_channels(StreamDevice *dev);
 
 typedef bool StreamMsgHandler(StreamDevice *dev, SpiceCharDeviceInstance *sin)
     SPICE_GNUC_WARN_UNUSED_RESULT;
@@ -520,6 +523,14 @@ stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin)
     return RED_CHAR_DEVICE(dev);
 }
 
+void
+stream_device_create_channel(RedCharDevice *char_dev)
+{
+    if (IS_STREAM_DEVICE(char_dev)) {
+        allocate_channels(STREAM_DEVICE(char_dev));
+    }
+}
+
 static void
 stream_device_dispose(GObject *object)
 {
-- 
2.14.3