+/*
+ * External references. The sftp client module sftp.c expects to be
+ * able to get at these functions.
+ *
+ * sftp_recvdata must never return less than len. It either blocks
+ * until len is available, or it returns failure.
+ *
+ * Both functions return 1 on success, 0 on failure.
+ */
+int sftp_senddata(char *data, int len);
+int sftp_recvdata(char *data, int len);
+