#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#define fir 16777216
#define sec 65536
#define the 256
 
int s;
struct sockaddr_in addr;
char rmt_host[100];
int skan(port)
int port;
{
 int r;
    s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (s < 0) {
       printf("ERROR: socket() failed\n");
       exit(0);
    }
 
    addr.sin_family = PF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = inet_addr(rmt_host);
 
    r = connect(s,(struct sockaddr *) &addr, sizeof(addr));
 
    close(s);
    if (r==-1) {
       return (1 == 0);
    }
 
    return (1 == 1);
}
 
main(argc,argv) 
int argc;
char *argv[];
{
 int a,b,c,d,e,f,w;
 struct hostent *foo,*rechner;
 struct servent *bar; 
 struct in_addr gesamt_ip;
 int i1,i2,i3,i4;
 unsigned long x,an;
 FILE *savefile;
   w=0;    
   if (argc < 2) {
      fprintf(stderr,"usage: %s <start IP> <number to scanning IP's>\n",argv[0]);
      exit(0);
   }
inet_aton(argv[1],&gesamt_ip);
sscanf(argv[1],"%d.%d.%d.%d",&i1,&i2,&i3,&i4);
sscanf(argv[2],"%lu",&an);
printf("Start IP: %s  - number to scanning IP's: %lu\n\n",inet_ntoa(gesamt_ip),an);
for(x=0;x<an;x++)
{
foo = gethostbyname(inet_ntoa(gesamt_ip));
rechner =gethostbyaddr((char *) &gesamt_ip, sizeof(gesamt_ip), AF_INET);
printf("Scanning %s ...",inet_ntoa(gesamt_ip));
  if (rechner == NULL) {
     fprintf(stderr,"Not aviable\n");
  }
  if (rechner != NULL){
  savefile=fopen("hosts","a+");
  fprintf(savefile,"OK-Domain: %s (%d.%d.%d.%d)\n",rechner->h_name ,(unsigned char )foo->h_addr_list[0][0],
              (unsigned char ) foo->h_addr_list[0][1], 
              (unsigned char ) foo->h_addr_list[0][2], 
              (unsigned char ) foo->h_addr_list[0][3]);
  printf("OK-Domain: %s",rechner->h_name);
  fclose(savefile);
  }
  sprintf(rmt_host,"%d.%d.%d.%d",(unsigned char )foo->h_addr_list[0][0],
              (unsigned char ) foo->h_addr_list[0][1], 
              (unsigned char ) foo->h_addr_list[0][2], 
              (unsigned char ) foo->h_addr_list[0][3]);
printf("\n");    
i4=i4+1;
gesamt_ip.s_addr=gesamt_ip.s_addr+fir;
if (i4 == 256)
{i4=0;i3=i3+1;w=3;gesamt_ip.s_addr=gesamt_ip.s_addr+sec;}
if (i3 == 256)
{i3=0;i2=i2+1;w=2;gesamt_ip.s_addr=gesamt_ip.s_addr+the;}
if (i2 == 256)
{i2=0;i1=i1+1;w=1;gesamt_ip.s_addr=gesamt_ip.s_addr+1;}
if (i1 == 256)
{exit(0);}
 
}
}

on the occasion of the current invasion of Russia in Ukraine