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#include "ipv4.h"
#include "net_sys.h"
#include "inet.h"
#include "eth.h"
#include "icmp.h"
bool ipv4_incoming(struct netdev *dev,struct eth_hdr *hdr)
{
struct ipv4_hdr *ipv4=hdr->payload;
// klog("ipv4 incoming with checksum: 0x%04X",ntohs(ipv4->csum));
ipv4->csum=0;
// klog("expected checksum: 0x%04X",checksum(ipv4,ntohs(ipv4->len)));
// klog("ipv4 header len=%d",ipv4->ihl);
if(ipv4->proto==IPV4_P_ICMP)
{
icmp_incoming(dev,hdr);
}
return true;
}
uint32_t ipv4_generic(struct netdev *dev, uint32_t ip, uint8_t type, uint8_t* pos,uint8_t *end)
{
pos-=20; // we need 20 bytes for the ipv4 header.
struct ipv4_hdr *ipv4=pos;
ipv4->ihl=5; // 20 bytes
ipv4->version=4; // ipv 4
ipv4->tos=0; // type of service?
ipv4->len=htons(end-pos); // total length of ip datagramm in bytes
ipv4->id=0; // index of datagram for fragmentation
//ipv4->flags=0x2; // various control flags 0x20 do not fragment
//ipv4->frag_offset=0; // fragment offset 0 - first
ipv4->flags_and_offset=0; // TODO! 0x2?
ipv4->ttl=64; // time to live - countdown decreased by each receiver
ipv4->proto=type; // payload protocol / 1-icmp, 16 - udp , 6 -tcp
ipv4->csum=0; // header checksum
ipv4->saddr=dev->ip; // source ip address
ipv4->daddr=ip; // destination ip address
//ipv4->csum=checksum(ipv4,ntohs(ipv4->len));
ipv4->csum=checksum(ipv4,20);
return eth_generic(dev,ip,ETH_P_IPV4,pos,end);
}
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