net/queue: export qemu_net_queue_append_iov

This will be used by buffer filter implementation later to
queue packets.

Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/queue.h

@@ -47,6 +47,13 @@ typedef ssize_t (NetQueueDeliverFunc)(NetClientState *sender,
 
 NetQueue *qemu_new_net_queue(NetQueueDeliverFunc *deliver, void *opaque);
 
+void qemu_net_queue_append_iov(NetQueue *queue,
+                               NetClientState *sender,
+                               unsigned flags,
+                               const struct iovec *iov,
+                               int iovcnt,
+                               NetPacketSent *sent_cb);
+
 void qemu_del_net_queue(NetQueue *queue);
 
 ssize_t qemu_net_queue_send(NetQueue *queue,