red-pipe-item: Better encapsulate marshaller_unref_pipe_item

To avoid memory errors marshaller_unref_pipe_item should be
matched with a previous call to red_pipe_item_ref.
This is correctly done but to reduce the possibility of breaking
this rule move both referencing and unreferencing into a new
RedPipeItem::add_to_marshaller method.

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Acked-by: Julien Ropé <jrope@gmail.com>

server/cursor-channel.cpp

@@ -89,9 +89,7 @@ static void cursor_fill(CursorChannelClient *ccc, RedCursorPipeItem *cursor,
 
     if (red_cursor->data_size) {
         SpiceMarshaller *m2 = spice_marshaller_get_submarshaller(m);
-        red_pipe_item_ref(&cursor->base);
-        spice_marshaller_add_by_ref_full(m2, red_cursor->data, red_cursor->data_size,
-                                         marshaller_unref_pipe_item, &cursor->base);
+        cursor->base.add_to_marshaller(m2, red_cursor->data, red_cursor->data_size);
     }
 }
 

server/dcc-send.cpp

@@ -1969,10 +1969,8 @@ static void red_marshall_image(DisplayChannelClient *dcc,
 
         spice_marshall_Image(src_bitmap_out, &red_image,
                              &bitmap_palette_out, &lzplt_palette_out);
-        red_pipe_item_ref(&item->base);
-        spice_marshaller_add_by_ref_full(src_bitmap_out, item->data,
-                                         bitmap.y * bitmap.stride,
-                                         marshaller_unref_pipe_item, item);
+        item->base.add_to_marshaller(src_bitmap_out, item->data,
+                                     bitmap.y * bitmap.stride);
         region_remove(surface_lossy_region, &copy.base.box);
     }
     spice_chunks_destroy(chunks);

server/main-channel-client.cpp

@@ -684,8 +684,7 @@ static void main_channel_marshall_agent_data(RedChannelClient *rcc,
 {
     rcc->init_send_data(SPICE_MSG_MAIN_AGENT_DATA);
     /* since pipe item owns the data, keep it alive until it's sent */
-    red_pipe_item_ref(&item->base);
-    spice_marshaller_add_by_ref_full(m, item->data, item->len, marshaller_unref_pipe_item, item);
+    item->base.add_to_marshaller(m, item->data, item->len);
 }
 
 static void main_channel_marshall_migrate_data_item(RedChannelClient *rcc,

server/red-pipe-item.cpp

@@ -47,8 +47,15 @@ void red_pipe_item_init_full(RedPipeItem *item,
     item->free_func = free_func ? free_func : (red_pipe_item_free_t *)g_free;
 }
 
-void marshaller_unref_pipe_item(uint8_t *data G_GNUC_UNUSED, void *opaque)
+static void marshaller_unref_pipe_item(uint8_t *, void *opaque)
 {
     RedPipeItem *item = (RedPipeItem*) opaque;
     red_pipe_item_unref(item);
 }
+
+void RedPipeItem::add_to_marshaller(SpiceMarshaller *m, uint8_t *data, size_t size)
+{
+    red_pipe_item_ref(this);
+    spice_marshaller_add_by_ref_full(m, data, size,
+                                     marshaller_unref_pipe_item, this);
+}

server/red-pipe-item.h

@@ -22,7 +22,9 @@
 #include <stddef.h>
 #include <inttypes.h>
 
-SPICE_BEGIN_DECLS
+#include "common/marshaller.h"
+
+#include "push-visibility.h"
 
 typedef struct RedPipeItem RedPipeItem;
 
@@ -31,6 +33,8 @@ typedef void red_pipe_item_free_t(RedPipeItem *item);
 struct RedPipeItem {
     int type;
 
+    void add_to_marshaller(SpiceMarshaller *m, uint8_t *data, size_t size);
+
     /* private */
     int refcount;
 
@@ -46,9 +50,6 @@ static inline void red_pipe_item_init(RedPipeItem *item, int type)
     red_pipe_item_init_full(item, type, NULL);
 }
 
-/* a convenience function for unreffing a pipe item after it has been sent */
-void marshaller_unref_pipe_item(uint8_t *data, void *opaque);
-
-SPICE_END_DECLS
+#include "pop-visibility.h"
 
 #endif /* RED_PIPE_ITEM_H_ */

server/smartcard-channel-client.cpp

@@ -121,12 +121,10 @@ void smartcard_channel_client_send_data(RedChannelClient *rcc,
 {
     spice_assert(rcc);
     spice_assert(vheader);
+    rcc->init_send_data(SPICE_MSG_SMARTCARD_DATA);
     /* NOTE: 'vheader' is assumed to be owned by 'item' so we keep the pipe
      * item valid until the message is actually sent. */
-    red_pipe_item_ref(item);
-    rcc->init_send_data(SPICE_MSG_SMARTCARD_DATA);
-    spice_marshaller_add_by_ref_full(m, (uint8_t*)vheader, sizeof(VSCMsgHeader) + vheader->length,
-                                     marshaller_unref_pipe_item, item);
+    item->add_to_marshaller(m, (uint8_t*)vheader, sizeof(VSCMsgHeader) + vheader->length);
 }
 
 void smartcard_channel_client_send_error(RedChannelClient *rcc, SpiceMarshaller *m, RedPipeItem *item)

server/spicevmc.cpp

@@ -532,9 +532,7 @@ static void spicevmc_red_channel_send_data(VmcChannelClient *rcc,
         };
         spice_marshall_SpiceMsgCompressedData(m, &compressed_msg);
     }
-    red_pipe_item_ref(item);
-    spice_marshaller_add_by_ref_full(m, i->buf, i->buf_used,
-                                     marshaller_unref_pipe_item, item);
+    item->add_to_marshaller(m, i->buf, i->buf_used);
 
     // account for sent data and wake up device if was blocked
     uint32_t old_queued_data = channel->queued_data;

server/stream-channel.cpp

@@ -234,9 +234,7 @@ void StreamChannelClient::send_item(RedPipeItem *pipe_item)
         StreamDataItem *item = SPICE_UPCAST(StreamDataItem, pipe_item);
         init_send_data(SPICE_MSG_DISPLAY_STREAM_DATA);
         spice_marshall_msg_display_stream_data(m, &item->data);
-        red_pipe_item_ref(pipe_item);
-        spice_marshaller_add_by_ref_full(m, item->data.data, item->data.data_size,
-                                         marshaller_unref_pipe_item, pipe_item);
+        pipe_item->add_to_marshaller(m, item->data.data, item->data.data_size);
         record(stream_channel_data, "Stream data packet size %u mm_time %u",
                item->data.data_size, item->data.base.multi_media_time);
         break;