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

[Frediano Ziglio]

Due to ticket expiration, is possible that the streaming channels for the
client are created after the ticket expires, this as 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).
This causes the client to not be able to connect to a new streaming
channel as the authentication would fail.
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(+)

Changes since v1:
- improve commit message.

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