net/arp.h


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// http://www.saminiir.com/lets-code-tcp-ip-stack-1-ethernet-arp/
//

#include <stdint.h>

#include "netdev.h"

struct arp_hdr
{
    uint16_t hwtype;	    // link layer type (1 - ethernet)
    uint16_t protype;	    // protocol (0x800 - ipv4)
    unsigned char hwsize;   // hardware field size (6 bytes mac)
    unsigned char prosize;  // protocol field size (4 byte ip)
    uint16_t opcode;	    // arp message type (1- arp request, 2- arp reply, 3- rarp request, 4- rarp reply)
    unsigned char data[];   // payload
} __attribute__((packed));

// arp ipv4 payload
struct arp_ipv4
{
    unsigned char smac[6];  // sender mac
    uint32_t sip;	    // sender ip
    unsigned char dmac[6];  // receiver mac
    uint32_t dip;	    // receiver ip
} __attribute__((packed));

void arp_incoming(struct netdev *netdev, struct eth_hdr *hdr);
void arp_reply(struct netdev *netdev, struct eth_hdr *hdr, struct arp_hdr *arphdr);