Add definitions for the different types of event that need processing by the TCP/IP stack.

Demo/Common/ethernet/FreeTCPIP/net/uip.h

@@ -2165,6 +2165,16 @@ u16_t	uip_udpchksum( void );
  * \return The ICMP checksum of the ICMP packet in uip_buf
  */
 u16_t	uip_icmp6chksum( void );
+
+/* Events that can get posted to the uIP event queue.  These are events
+originating from the Ethernet interface or from a timer. */
+#define uipETHERNET_RX_EVENT		0x01UL
+#define	uipETHERNET_TX_EVENT		0x02UL
+#define uipARP_TIMER_EVENT			0x04UL
+#define uipPERIODIC_TIMER_EVENT		0x08UL
+#define uipAPPLICATION_SEND_EVENT	0x10UL
+
+
 #endif /* __UIP_H__ */
 
 /** @} */