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#include "inet.h"
#include "icmp.h"
#include "ipv4.h"
#include "log.h"
#include "lib/string/string.h"
bool icmp_reply(struct netdev *dev,struct eth_hdr *hdr)
{
unsigned char tmp[6];
memcpy(tmp,hdr->dmac,6);
memcpy(hdr->dmac,hdr->smac,6);
memcpy(hdr->smac,tmp,6);
struct ipv4_hdr *ipv4=hdr->payload;
uint32_t tmp2;
tmp2=ipv4->saddr;
ipv4->saddr=ipv4->daddr;
ipv4->daddr=tmp2;
uint32_t daddr; // destination ip address
struct icmp_v4 *data=(uint32_t *)ipv4+ipv4->ihl;
data->type=ICMP_ECHO_REPLY;
data->csum=0;
ipv4->csum=0;
data->csum=htons(checksum(data,ipv4->len-ipv4->ihl*4));
ipv4->csum=htons(checksum(ipv4,ntohs(ipv4->len)));
dev->transmit(hdr,ntohs(ipv4->len)+14); // 14bytes for link2
return true;
}
bool icmp_incoming(struct netdev *dev,struct eth_hdr *hdr)
{
struct ipv4_hdr *ipv4=hdr->payload;
struct icmp_v4 *data=(uint32_t *)ipv4+ipv4->ihl;
klog ("icmp type=%d",data->type);
klog ("icmp code=%d",data->code);
klog ("icmp csum=0x%04x",ntohs(data->csum));
data->csum=0;
klog("expected checksum = 0x%04X",checksum(data,ipv4->len-ipv4->ihl*4));
if(data->type==ICMP_ECHO_REQUEST) // echo request
{
struct icmp_v4_echo *echo=data->data;
klog ("received echo request id=%d, seq=%d, data=%d ",ntohs(echo->id),ntohs(echo->seq),echo->data);
icmp_reply(dev,hdr); /// TODO watchout that this is the memory managed by the network card we are dealing with!!. fix this later.
}
return true;
}
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