void icmpEchoRequest(icmpip_hdr* packet)
{
uint32_t tempIp;
// change type to reply
packet->icmp.type = ICMP_TYPE_ECHOREPLY;
// recalculate checksum
packet->icmp.icmpchksum = 0;
packet->icmp.icmpchksum = netChecksum((uint8_t*)&packet->icmp, htons(packet->ip.len)-IP_HEADER_LEN);
// return to sender
tempIp = packet->ip.destipaddr;
packet->ip.destipaddr = packet->ip.srcipaddr;
packet->ip.srcipaddr = tempIp;
// add ethernet routing
arpIpOut((struct netEthIpHeader*)(((uint8_t*)packet)-ETH_HEADER_LEN), 0);
// debugging
#if NET_DEBUG >= 2
icmpPrintHeader(packet);
//debugPrintHexTable(htons(packet->ip.len), (u08*)packet);
#endif
// send it (packet->ip.len+ETH_HEADER_LEN
nicSend(htons(packet->ip.len)+ETH_HEADER_LEN, (((uint8_t*)packet)-ETH_HEADER_LEN));
}
void ipSend(uint32_t dstIp, uint8_t protocol, uint16_t len, uint8_t* data)
{
// make pointer to ethernet/IP header
struct netEthIpHeader* ethIpHeader;
// move data pointer to make room for headers
data -= ETH_HEADER_LEN+IP_HEADER_LEN;
ethIpHeader = (struct netEthIpHeader*)data;
// debugPrintHexTable(len+ETH_HEADER_LEN+IP_HEADER_LEN, data);
// adjust length to add IP header
len += IP_HEADER_LEN;
// fill IP header
ethIpHeader->ip.destipaddr = HTONL(dstIp);
ethIpHeader->ip.srcipaddr = HTONL(IpMyConfig.ip);
ethIpHeader->ip.proto = protocol;
ethIpHeader->ip.len = htons(len);
ethIpHeader->ip.vhl = 0x45;
ethIpHeader->ip.tos = 0;
ethIpHeader->ip.ipid = 0;
ethIpHeader->ip.ipoffset = 0;
ethIpHeader->ip.ttl = IP_TIME_TO_LIVE;
ethIpHeader->ip.ipchksum = 0;
// calculate and apply IP checksum
// DO THIS ONLY AFTER ALL CHANGES HAVE BEEN MADE TO IP HEADER
ethIpHeader->ip.ipchksum = netChecksum(ðIpHeader->ip, IP_HEADER_LEN);
// add ethernet routing
// check if we need to send to gateway
if( (dstIp & IpMyConfig.netmask) == (IpMyConfig.ip & IpMyConfig.netmask) )
{
arpIpOut(ethIpHeader,0); // local send
//rprintf("Sending IP packet on local net\r\n");
}
else
{
arpIpOut(ethIpHeader,IpMyConfig.gateway); // gateway send
//rprintf("Sending IP packet to gateway\r\n");
}
// adjust length to add ethernet header
len += ETH_HEADER_LEN;
// debug
//debugPrintHexTable(ETH_HEADER_LEN, &data[0]);
//debugPrintHexTable(len-ETH_HEADER_LEN, &data[ETH_HEADER_LEN]);
// send it
nicSend(len, data);
}