reg_apps Variable

struct arp_app_callbacks reg_apps[MAX_REG_APPS];

Call-Backs storage for MAX of two Modules/Apps 

// ARP packet structure typedef struct __attribute__((aligned(2), packed)) { WORD HardwareType; WORD Protocol; BYTE MACAddrLen; BYTE ProtocolLen; WORD Operation; MAC_ADDR SenderMACAddr; IP_ADDR SenderIPAddr; MAC_ADDR TargetMACAddr; IP_ADDR TargetIPAddr; } ARP_PACKET;