ICMPState Variable

enum {
  SM_IDLE = 0,
  SM_DNS_SEND_QUERY,
  SM_DNS_GET_RESPONSE,
  SM_ARP_SEND_QUERY,
  SM_ARP_GET_RESPONSE,
  SM_ICMP_SEND_ECHO_REQUEST,
  SM_ICMP_GET_ECHO_RESPONSE
} ICMPState;

ICMP State Machine Enumeration