random-ip.c

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#include "buffer.h"
#include "exit.h"
#include "fmt.h"
#include "scan.h"
#include "dns.h"
 
/* Generates random IPv4 numbers for tests only */
 
char ip[4];
int ipfixed = 0;
unsigned long loops = 10000;
unsigned char tab[256];
 
char strnum[FMT_ULONG];
 
char seed[128];
 
int main(int argc,char **argv)
{
  unsigned long u;
  int i;
  int j;
  unsigned char c;
 
  dns_random_init(seed);
 
  for (i = 0; i < 256; ++i) tab[i] = i;
  for (j = 256; j > 0 ;--j) {
    i = dns_random(j);
    c = tab[j - 1];
    tab[j - 1] = tab[i];
    tab[i] = c;
  }
 
  if (*argv) ++argv;
  if (*argv) scan_ulong(*argv++,&loops);
  if (*argv) { scan_ulong(*argv++,&u); ip[0] = u; ipfixed = 1; }
  if (*argv) { scan_ulong(*argv++,&u); ip[1] = u; ipfixed = 2; }
  if (*argv) { scan_ulong(*argv++,&u); ip[2] = u; ipfixed = 3; }
  if (*argv) { scan_ulong(*argv++,&u); ip[3] = u; ipfixed = 4; }
 
  if (ipfixed >= 1) if (loops > 16777216) loops = 16777216;
  if (ipfixed >= 2) if (loops > 65536) loops = 65536;
  if (ipfixed >= 3) if (loops > 256) loops = 256;
  if (ipfixed >= 4) if (loops > 1) loops = 1;
 
  while (loops) {
    --loops;
    u = loops;
    for (i = ipfixed; i < 4; ++i) { ip[i] = u & 255; u >>= 8; }
    if (ipfixed == 3) {
      c = ip[3];
      ip[3] = tab[c];
    }
    else if (ipfixed < 3) {
      c = 0;
      for (j = 0; j < 100; ++j) {
        for (i = ipfixed;i < 4;++i) {
          c ^= (unsigned char) ip[i];
          c = tab[c];
          ip[i] = c;
        }
      }
    }
 
    u = (unsigned char) ip[0];
    buffer_put(buffer_1,strnum,fmt_ulong(strnum,u));
    buffer_puts(buffer_1,".");
    u = (unsigned char) ip[1];
    buffer_put(buffer_1,strnum,fmt_ulong(strnum,u));
    buffer_puts(buffer_1,".");
    u = (unsigned char) ip[2];
    buffer_put(buffer_1,strnum,fmt_ulong(strnum,u));
    buffer_puts(buffer_1,".");
    u = (unsigned char) ip[3];
    buffer_put(buffer_1,strnum,fmt_ulong(strnum,u));
    buffer_puts(buffer_1,"\n");
  }
 
  buffer_flush(buffer_1);
  _exit(0);
}