/*

* Definitions for ARP/RARP protocol implementation

*/

////

// Constants

////

#define ARP_HW_TYPE_ETHERNET 0x0001

#define ARP_PROTO_TYPE_IPV4 0x0800

#define ARP_OPCODE_REQUEST 0x0001

#define ARP_OPCODE_ANSWER 0x0002

#define RARP_OPCODE_REQUEST 0x0003

#define RARP_OPCODE_ANSWER 0x0004

#define ARP_CACHE_TIMEOUT 120

////

// Structures

////

#pragma pack(1)

typedef struct{

short int hw_type;

short int proto_type;

unsigned char hw_addr_len;

unsigned char proto_addr_len;

short int opcode;

unsigned char addresses[1];

} ARP_fields;

#pragma pack()

typedef struct{

EthernetAddress ethernet;

IPv4Address ipv4;

time_t timestamp;

} ARP_cache_entry;

typedef struct{

int allocated;

int size;

ARP_cache_entry *entries;

} ARP_cache;

////

// Prototypes

////

#ifdef VERBOSE

void displayARPPacket(FILE *output,ARP_fields *arp,int size);

#endif

unsigned char arpSendPacket(EventsEvent *event,EventsSelector *selector);

unsigned char arpDecodePacket(EventsEvent *event,EventsSelector *selector);

#ifdef VERBOSE

void arpDisplay(FILE *output);

#endif

void arpPurgeCache(void);

void arpAddToCache(IPv4Address ip,EthernetAddress ether,unsigned char force);

EthernetAddress arpFindInCache(IPv4Address ip);

IPv4Address arpReverseFindInCache(EthernetAddress ethernet);