char_device: Add spice_char_device_write_buffer_get_server_no_token()

To allow the server to send agent messages without needing to wait for a
self-token. IE for sending VD_AGENT_CLIENT_DISCONNECTED messages.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

2 files changed, 29 insertions, 15 deletions

diff --git a/server/char_device.c b/server/char_device.c
index 49c5dc04..e07eda1f 100644
--- a/server/char_device.c
+++ b/server/char_device.c
@@ -72,6 +72,7 @@ enum {
     WRITE_BUFFER_ORIGIN_NONE,
     WRITE_BUFFER_ORIGIN_CLIENT,
     WRITE_BUFFER_ORIGIN_SERVER,
+    WRITE_BUFFER_ORIGIN_SERVER_NO_TOKEN,
 };
 
 /* Holding references for avoiding access violation if the char device was
@@ -488,15 +489,14 @@ static void spice_char_dev_write_retry(void *opaque)
     spice_char_device_write_to_device(dev);
 }
 
-static SpiceCharDeviceWriteBuffer *__spice_char_device_write_buffer_get(SpiceCharDeviceState *dev,
-                                                                        RedClient *client,
-                                                                        int size,
-                                                                        int migrated_data_tokens)
+static SpiceCharDeviceWriteBuffer *__spice_char_device_write_buffer_get(
+    SpiceCharDeviceState *dev, RedClient *client,
+    int size, int origin, int migrated_data_tokens)
 {
     RingItem *item;
     SpiceCharDeviceWriteBuffer *ret;
 
-    if (!client && !dev->num_self_tokens) {
+    if (origin == WRITE_BUFFER_ORIGIN_SERVER && !dev->num_self_tokens) {
         return NULL;
     }
 
@@ -513,8 +513,10 @@ static SpiceCharDeviceWriteBuffer *__spice_char_device_write_buffer_get(SpiceCha
         ret->buf = spice_realloc(ret->buf, size);
         ret->buf_size = size;
     }
+    ret->origin = origin;
 
-    if (client) {
+    if (origin == WRITE_BUFFER_ORIGIN_CLIENT) {
+       spice_assert(client);
        SpiceCharDeviceClientState *dev_client = spice_char_device_client_find(dev, client);
        if (dev_client) {
             if (!migrated_data_tokens &&
@@ -523,7 +525,6 @@ static SpiceCharDeviceWriteBuffer *__spice_char_device_write_buffer_get(SpiceCha
                 spice_char_device_handle_client_overflow(dev_client);
                 goto error;
             }
-            ret->origin = WRITE_BUFFER_ORIGIN_CLIENT;
             ret->client = client;
             if (!migrated_data_tokens && dev_client->do_flow_control) {
                 dev_client->num_client_tokens--;
@@ -534,8 +535,7 @@ static SpiceCharDeviceWriteBuffer *__spice_char_device_write_buffer_get(SpiceCha
             spice_printerr("client not found: dev %p client %p", dev, client);
             goto error;
         }
-    } else {
-        ret->origin = WRITE_BUFFER_ORIGIN_SERVER;
+    } else if (origin == WRITE_BUFFER_ORIGIN_SERVER) {
         dev->num_self_tokens--;
     }
 
@@ -551,7 +551,16 @@ SpiceCharDeviceWriteBuffer *spice_char_device_write_buffer_get(SpiceCharDeviceSt
                                                                RedClient *client,
                                                                int size)
 {
-   return  __spice_char_device_write_buffer_get(dev, client, size, 0);
+   return  __spice_char_device_write_buffer_get(dev, client, size, 
+             client ? WRITE_BUFFER_ORIGIN_CLIENT : WRITE_BUFFER_ORIGIN_SERVER,
+             0);
+}
+
+SpiceCharDeviceWriteBuffer *spice_char_device_write_buffer_get_server_no_token(
+    SpiceCharDeviceState *dev, int size)
+{
+   return  __spice_char_device_write_buffer_get(dev, NULL, size, 
+             WRITE_BUFFER_ORIGIN_SERVER_NO_TOKEN, 0);
 }
 
 static SpiceCharDeviceWriteBuffer *spice_char_device_write_buffer_ref(SpiceCharDeviceWriteBuffer *write_buf)
@@ -945,12 +954,14 @@ int spice_char_device_state_restore(SpiceCharDeviceState *dev,
 
     if (mig_data->write_size > 0) {
         if (mig_data->write_num_client_tokens) {
-            dev->cur_write_buf = __spice_char_device_write_buffer_get(dev, client_state->client,
-                                                                      mig_data->write_size,
-                                                                      mig_data->write_num_client_tokens);
+            dev->cur_write_buf =
+                __spice_char_device_write_buffer_get(dev, client_state->client,
+                    mig_data->write_size, WRITE_BUFFER_ORIGIN_CLIENT,
+                    mig_data->write_num_client_tokens);
         } else {
-            dev->cur_write_buf = __spice_char_device_write_buffer_get(dev, NULL, mig_data->write_size,
-                                                                      0);
+            dev->cur_write_buf =
+                __spice_char_device_write_buffer_get(dev, NULL,
+                    mig_data->write_size, WRITE_BUFFER_ORIGIN_SERVER, 0);
         }
         /* the first write buffer contains all the data that was saved for migration */
         memcpy(dev->cur_write_buf->buf,
diff --git a/server/char_device.h b/server/char_device.h
index 8bfe4ec6..99bdb2e2 100644
--- a/server/char_device.h
+++ b/server/char_device.h
@@ -181,6 +181,9 @@ void spice_char_device_send_to_client_tokens_set(SpiceCharDeviceState *dev,
 
 SpiceCharDeviceWriteBuffer *spice_char_device_write_buffer_get(SpiceCharDeviceState *dev,
                                                                RedClient *client, int size);
+SpiceCharDeviceWriteBuffer *spice_char_device_write_buffer_get_server_no_token(
+    SpiceCharDeviceState *dev, int size);
+
 /* Either add the buffer to the write queue or release it */
 void spice_char_device_write_buffer_add(SpiceCharDeviceState *dev,
                                         SpiceCharDeviceWriteBuffer *write_buf);