stream-device: Start supporting resetting device when close/open on guest

When guest close the device the host device has to be reset too.
This make easier to restart the guest device which can happen in case
of reboot, agent issues or if we want to update the agent.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Jonathon Jongsma <jjongsma@redhat.com>

server/stream-channel.c

@@ -483,3 +483,37 @@ stream_channel_register_start_cb(StreamChannel *channel,
     channel->start_cb = cb;
     channel->start_opaque = opaque;
 }
+
+void
+stream_channel_reset(StreamChannel *channel)
+{
+    struct {
+        StreamMsgStartStop base;
+        uint8_t codecs_buffer[MAX_SUPPORTED_CODECS];
+    } start_msg;
+    StreamMsgStartStop *const start = &start_msg.base;
+    RedChannel *red_channel = RED_CHANNEL(channel);
+
+    // send destroy old stream
+    red_channel_pipes_add_type(red_channel, RED_PIPE_ITEM_TYPE_STREAM_DESTROY);
+
+    // destroy display surface
+    if (channel->width != 0 && channel->height != 0) {
+        red_channel_pipes_add_type(red_channel, RED_PIPE_ITEM_TYPE_SURFACE_DESTROY);
+    }
+
+    channel->stream_id = -1;
+    channel->width = 0;
+    channel->height = 0;
+
+    if (!red_channel_is_connected(red_channel)) {
+        return;
+    }
+
+    // try to request a new stream, this should start a new stream
+    // if the guest is connected to the device and a client is already connected
+    start->num_codecs = stream_channel_get_supported_codecs(channel, start->codecs);
+    // send in any case, even if list is not changed
+    // notify device about changes
+    request_new_stream(channel, start);
+}

server/stream-channel.h

@@ -48,7 +48,12 @@ GType stream_channel_get_type(void) G_GNUC_CONST;
  */
 StreamChannel* stream_channel_new(RedsState *server, uint32_t id);
 
-struct StreamMsgFormat;
+/**
+ * Reset channel at initial state
+ */
+void stream_channel_reset(StreamChannel *channel);
+
+struct StreamMsgStreamFormat;
 struct StreamMsgStartStop;
 
 void stream_channel_change_format(StreamChannel *channel,

server/stream-device.c

@@ -43,6 +43,7 @@ struct StreamDevice {
     StreamDevHeader hdr;
     uint8_t hdr_pos;
     bool has_error;
+    bool opened;
     StreamChannel *stream_channel;
 };
 
@@ -203,6 +204,35 @@ stream_device_remove_client(RedCharDevice *self, RedClient *client)
 {
 }
 
+static void
+stream_device_stream_start(void *opaque, StreamMsgStartStop *start,
+                           StreamChannel *stream_channel G_GNUC_UNUSED)
+{
+    StreamDevice *dev = (StreamDevice *) opaque;
+
+    if (!dev->opened) {
+        return;
+    }
+
+    int msg_size = sizeof(*start) + sizeof(start->codecs[0]) * start->num_codecs;
+    int total_size = sizeof(StreamDevHeader) + msg_size;
+
+    RedCharDevice *char_dev = RED_CHAR_DEVICE(dev);
+    RedCharDeviceWriteBuffer *buf =
+        red_char_device_write_buffer_get_server_no_token(char_dev, total_size);
+    buf->buf_used = total_size;
+
+    StreamDevHeader *hdr = (StreamDevHeader *)buf->buf;
+    hdr->protocol_version = STREAM_DEVICE_PROTOCOL;
+    hdr->padding = 0;
+    hdr->type = GUINT16_TO_LE(STREAM_TYPE_START_STOP);
+    hdr->size = GUINT32_TO_LE(msg_size);
+
+    memcpy(&hdr[1], start, msg_size);
+
+    red_char_device_write_buffer_add(char_dev, buf);
+}
+
 RedCharDevice *
 stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin)
 {
@@ -212,6 +242,7 @@ stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin)
 
     StreamDevice *dev = stream_device_new(sin, reds);
     dev->stream_channel = stream_channel;
+    stream_channel_register_start_cb(stream_channel, stream_device_stream_start, dev);
 
     sif = spice_char_device_get_interface(sin);
     if (sif->state) {
@@ -233,6 +264,23 @@ stream_device_dispose(GObject *object)
     }
 }
 
+static void
+stream_device_port_event(RedCharDevice *char_dev, uint8_t event)
+{
+    if (event != SPICE_PORT_EVENT_OPENED && event != SPICE_PORT_EVENT_CLOSED) {
+        return;
+    }
+
+    StreamDevice *dev = STREAM_DEVICE(char_dev);
+
+    // reset device and channel on close/open
+    dev->opened = (event == SPICE_PORT_EVENT_OPENED);
+    dev->hdr_pos = 0;
+    dev->has_error = false;
+    red_char_device_reset(char_dev);
+    stream_channel_reset(dev->stream_channel);
+}
+
 static void
 stream_device_class_init(StreamDeviceClass *klass)
 {
@@ -245,6 +293,7 @@ stream_device_class_init(StreamDeviceClass *klass)
     char_dev_class->send_msg_to_client = stream_device_send_msg_to_client;
     char_dev_class->send_tokens_to_client = stream_device_send_tokens_to_client;
     char_dev_class->remove_client = stream_device_remove_client;
+    char_dev_class->port_event = stream_device_port_event;
 }
 
 static void