u08 icmp_receive_packet( ip_header * p, u16 len )
{
icmp_header * icmp = ( icmp_header * )__ip_payload( p );
log_printf( "icmp: got packet, type=%d code=%d\n", icmp->type, icmp->code );
if (icmp->type == 8 && icmp->code == 0)
icmp_send_reply( p, icmp, len );
return 1;
}
int sr_handle_arpreq(struct sr_instance *sr, struct sr_arpreq *request){
time_t now = get_now(&now);
struct sr_packet * packetptr = request->packets;
int i;
if(difftime(now, request->sent) > 1.0){
if(request->times_sent >= 5){
while(packetptr != NULL){
icmp_send_reply(sr, (uint8_t *)packetptr, packetptr->len, packetptr->iface, 3, 1); /* send unreachable */
packetptr = packetptr->next;
}
sr_arpreq_destroy(&(sr->cache), request);
return -1;
}else{
struct sr_rt* entry;
struct sr_rt* routing = sr->routing_table;
for(entry = routing; entry != NULL; entry = routing->next){
struct sr_if * interface2 = sr_get_interface(sr, entry->interface);
/*create arp packet*/
enum sr_arp_opcode opcode = arp_op_request;
struct sr_packet *raw = malloc(sizeof(struct sr_arp_hdr) + ETHER_HDR_LEN);
/* may need to memset here*/
struct sr_ethernet_hdr *eth = (struct sr_ethernet_hdr *)raw;
struct sr_arp_hdr *req = (struct sr_arp_hdr *)(raw + ETHER_HDR_LEN);
req->ar_hrd = 0;
req->ar_pro = 0;
req->ar_hln = 0;
req->ar_pln = 0;
req->ar_op = opcode;
req->ar_sip = sr->sr_addr.sin_addr.s_addr;
req->ar_tip = request->ip;
for (i = 0; i < ETHER_ADDR_LEN; i++){
req->ar_tha[i] = 0xff;
req->ar_sha[i] = interface2->addr[i];
eth->ether_dhost[i] = 0xff;
eth->ether_shost[i] = interface2->addr[i];
}
/*send packet to the interface on routing_table*/
sr_send_packet(sr, (uint8_t *)raw, sizeof(struct sr_arp_hdr) + ETHER_HDR_LEN, request->packets->iface);
free(raw);
}
request->sent = now;
request->times_sent++;
}
}
return 0;
}
//*****************************************************************************************
//
// Function : server_process
// Description : Run web server and listen on port 80
//
//*****************************************************************************************
void server_process ( void )
{
MAC_ADDR client_mac;
IP_ADDR client_ip;
// you can change rx,tx buffer size in includes.h
BYTE rxtx_buffer[MAX_RXTX_BUFFER];
WORD plen;
if ( flag1.bits.syn_is_sent )
return;
// get new packet
plen = enc28j60_packet_receive( (BYTE*)&rxtx_buffer, MAX_RXTX_BUFFER );
//plen will ne unequal to zero if there is a valid packet (without crc error)
if(plen==0)
return;
// copy client mac address from buffer to client mac variable
memcpy ( (BYTE*)&client_mac, &rxtx_buffer[ ETH_SRC_MAC_P ], sizeof(MAC_ADDR) );
// check arp packet if match with avr ip let's send reply
if ( arp_packet_is_arp( rxtx_buffer, (WORD_BYTES){ARP_OPCODE_REQUEST_V} ) )
{
arp_send_reply ( (BYTE*)&rxtx_buffer, (BYTE*)&client_mac );
return;
}
// get client ip address
memcpy ( (BYTE*)&client_ip, &rxtx_buffer[ IP_SRC_IP_P ], sizeof(IP_ADDR) );
// check ip packet send to avr or not?
if ( ip_packet_is_ip ( (BYTE*)&rxtx_buffer ) == 0 )
{
return;
}
// check packet if packet is icmp packet let's send icmp echo reply
if ( icmp_send_reply ( (BYTE*)&rxtx_buffer, (BYTE*)&client_mac, (BYTE*)&client_ip ) )
{
return;
}
// start web server at port 80, see http.c
http_webserver_process ( (BYTE*)rxtx_buffer, (BYTE*)&client_mac, (BYTE*)&client_ip );
}
