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#include <assert.h>
#include <drivers/rtl8139.h>
#include <network/arp.h>
#include <network/bytes.h>
#include <network/ethernet.h>
#include <stdio.h>
#include <string.h>
struct ARP_DATA {
uint16_t htype; // Hardware type
uint16_t ptype; // Protocol type
uint8_t hlen; // Hardware address length (Ethernet = 6)
uint8_t plen; // Protocol address length (IPv4 = 4)
uint16_t opcode; // ARP Operation Code
uint8_t srchw[6]; // Source hardware address - hlen bytes (see above)
uint8_t srcpr[4]; // Source protocol address - plen bytes (see above).
// If IPv4 can just be a "u32" type.
uint8_t dsthw[6]; // Destination hardware address - hlen bytes (see above)
uint8_t dstpr[4]; // Destination protocol address - plen bytes (see
// above). If IPv4 can just be a "u32" type.
};
// FIXME: This is hardcoded, don't do this.
uint8_t ip_address[4] = {10, 0, 2, 15};
void print_mac(const char *str, uint8_t *mac) {
kprintf("%s: ", str);
for (int i = 0; i < 6; i++) {
kprintf("%x", mac[i]);
if (5 != i)
kprintf(":");
}
kprintf("\n");
}
void print_ip(const char *str, uint8_t *ip) {
kprintf("%s: ", str);
for (int i = 0; i < 4; i++) {
kprintf("%d", ip[i]);
if (3 != i)
kprintf(".");
}
kprintf("\n");
}
void handle_arp(const uint8_t *payload) {
struct ARP_DATA *data = (struct ARP_DATA *)payload;
// Assert that communication is over ethernet
assert(1 == ntohs(data->htype));
// Assert it is a request
assert(0x0001 == ntohs(data->opcode));
// Assert that request uses IP
assert(0x0800 == ntohs(data->ptype));
assert(6 == data->hlen);
assert(4 == data->plen);
print_mac("srchw: ", data->srchw);
print_ip("srcpr: ", data->srcpr);
print_mac("dsthw: ", data->dsthw);
print_ip("dstpr: ", data->dstpr);
uint8_t mac[6];
get_mac_address(mac);
print_mac("THIS DEVICE MAC: ", mac);
assert(0 == memcmp(data->dstpr, ip_address, sizeof(uint8_t[4])));
// Now we have to construct a ARP response
struct ARP_DATA response;
response.htype = htons(1);
response.ptype = htons(0x0800);
response.opcode = htons(0x00002);
response.hlen = 6;
response.plen = 4;
get_mac_address(response.srchw);
memcpy(response.srcpr, ip_address, sizeof(uint8_t[4]));
memcpy(response.dsthw, data->srchw, sizeof(uint8_t[6]));
memcpy(response.dstpr, data->srcpr, sizeof(uint8_t[4]));
send_ethernet_packet(data->srchw, 0x0806, (uint8_t *)&response,
sizeof(response));
}
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