diff --git a/src/mirror.h b/src/mirror.h
new file mode 100644
index 0000000..9e4ee0c
--- /dev/null
+++ b/src/mirror.h
@@ -0,0 +1,94 @@
+#ifndef MIRROR_H
+#define MIRROR_H
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include "bitset.h"
+#include "self_pipe.h"
+enum mirror_state;
+#include "serve.h"
+
+/* MS_CONNECT_TIME_SECS
+ * The length of time after which the sender will assume a connect() to
+ * the destination has failed.
+ */
+#define MS_CONNECT_TIME_SECS 60
+
+/* MS_HELLO_TIME_SECS
+ * The length of time the sender will wait for the NBD hello message
+ * after connect() before aborting the connection attempt.
+ */
+#define MS_HELLO_TIME_SECS 5
+
+
+/* MS_RETRY_DELAY_SECS
+ * The delay after a failed migration attempt before launching another
+ * thread to try again.
+ */
+#define MS_RETRY_DELAY_SECS 1
+
+enum mirror_finish_action {
+	ACTION_EXIT,
+	ACTION_NOTHING
+};
+
+enum mirror_state {
+	MS_UNKNOWN,
+	MS_INIT,
+	MS_GO,
+	MS_FINALISE,
+	MS_DONE,
+	MS_FAIL_CONNECT,
+	MS_FAIL_REJECTED,
+	MS_FAIL_NO_HELLO,
+	MS_FAIL_SIZE_MISMATCH
+};
+
+struct mirror_status {
+	pthread_t            thread;
+	/* set to 1, then join thread to make mirror terminate early */
+	int                  signal_abandon;
+	union mysockaddr *   connect_to;
+	union mysockaddr *   connect_from;
+	int                  client;
+	const char *         filename;
+	off64_t              max_bytes_per_second;
+	enum mirror_finish_action action_at_finish;
+	
+	char                 *mapped;
+	struct bitset_mapping *dirty_map;
+
+	enum mirror_state   commit_state;
+
+	/* commit_signal is sent immediately after attempting to connect
+	 * and checking the remote size, whether successful or not.
+	 */
+	struct self_pipe *   commit_signal;
+};
+
+
+struct mirror_super {
+	struct mirror_status * mirror;
+	pthread_t thread;
+	struct mbox * state_mbox;
+};
+
+
+
+/* We need these declaration to get around circular dependencies in the
+ * .h's
+ */
+struct server;
+struct flexnbd;
+
+struct mirror_super * mirror_super_create(
+		const char * filename,
+		union mysockaddr * connect_to,
+		union mysockaddr * connect_from,
+		int max_Bps,
+		int action_at_finish);
+void * mirror_super_runner( void * serve_uncast );
+enum mirror_state mirror_super_wait( struct mirror_super * );
+#endif