+/* flags for "fce_ev_info" of additional info to send in events */
+#define FCE_EV_INFO_PID (1 << 0)
+#define FCE_EV_INFO_USER (1 << 1)
+#define FCE_EV_INFO_SRCPATH (1 << 2)
+
+/*
+ * Network payload of an FCE packet, version 1
+ *
+ * 1 2 3 4 5 6 7 8
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | FCE magic |
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | version |
+ * +---------+
+ * | event |
+ * +---------+-----------------------------+
+ * | event ID |
+ * +-------------------+-------------------+ . . . .
+ * | pathlen | path
+ * +-------------------+------ . . . . . . . . . . .
+ *
+ *
+ * Network payload of an FCE packet, version 2
+ *
+ * 1 2 3 4 5 6 7 8
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | FCE magic |
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | version |
+ * +---------+
+ * | options |
+ * +---------+
+ * | event |
+ * +---------+
+ * | padding |
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | reserved |
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | event ID |
+ * +---------+---------+---------+---------+
+ * ... optional:
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * | pid |
+ * +---------+---------+---------+---------+---------+---------+----------+----------+
+ * ...
+ * ... optional:
+ * +-------------------+---------- . . . .
+ * | username length | username
+ * +-------------------+---------- . . . .
+ * ...
+ * +-------------------+------ . . . . . .
+ * | pathlen | path
+ * +-------------------+------ . . . . . .
+ * ... optional:
+ * +-------------------+------------- . . .
+ * | pathlen | source path
+ * +-------------------+------------- . . .
+ *
+ * version = 2
+ * options = bitfield:
+ * 0: pid present
+ * 1: username present
+ * 2: source path present
+ * pid = optional pid
+ * username = optional username
+ * source path = optional source path