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#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_icmp.h>
#include <arpa/inet.h>
#include "emulate/internet.h"
#include "scheduler.h"
/*
* in_cksum --
* Checksum routine for Internet Protocol family headers (C Version)
* [taken from ping.c]
*/
u_short
Internet::in_cksum(u_short* addr, int len)
{
register int nleft = len;
register u_short *w = addr;
register int sum = 0;
u_short answer = 0;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum), we add
* sequential 16 bit words to it, and at the end, fold back all the
* carry bits from the top 16 bits into the lower 16 bits.
*/
while (nleft > 1) {
sum += *w++;
nleft -= 2;
}
/* mop up an odd byte, if necessary */
if (nleft == 1) {
*(u_char *)(&answer) = *(u_char *)w ;
sum += answer;
}
/* add back carry outs from top 16 bits to low 16 bits */
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = ~sum; /* truncate to 16 bits */
return(answer);
}
#include <netinet/in_systm.h>
#include <netinet/ip.h>
void
Internet::print_ip(ip *ip)
{
u_short off = ntohs(ip->ip_off);
printf("IP v:%d, ihl:%d, tos:0x%x, id:%d, off:%d [df:%d, mf:%d], "
"sum:%d, prot:%d\n",
ip->ip_v, ip->ip_hl, ip->ip_tos, ntohs(ip->ip_id),
off & IP_OFFMASK,
(off & IP_DF) ? 1 : 0,
(off & IP_MF) ? 1 : 0,
ip->ip_sum, ip->ip_p);
printf("IP src:%s, ", inet_ntoa(ip->ip_src));
printf("dst: %s\n", inet_ntoa(ip->ip_dst));
printf("IP len:%d ttl: %d\n",
ntohs(ip->ip_len), ip->ip_ttl);
}
/*
* cons up a basic-looking ip header, no options
* multi-byte quantities are assumed to be in HOST byte order
*/
void
Internet::makeip(ip* iph, u_short len, u_char ttl, u_char proto, in_addr& src,
in_addr& dst)
{
u_char *p = (u_char*) iph;
*p = 0x45; /* ver + hl */
iph->ip_tos = 0;
iph->ip_len = htons(len);
iph->ip_id = (u_short) Scheduler::instance().clock(); // why not?
iph->ip_off = 0x0000; // mf and df bits off, offset zero
iph->ip_ttl = ttl;
iph->ip_p = proto;
memcpy(&iph->ip_src, &src, 4);
memcpy(&iph->ip_dst, &dst, 4);
iph->ip_sum = Internet::in_cksum((u_short*) iph, 20);
return;
}
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