netem/pareto.c

   1 /*
   2  * Pareto distribution table generator
   3  * Taken from the uncopyrighted NISTnet code.
   4  */
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <math.h>
   8 #include <limits.h>
   9
  10 #include <linux/types.h>
  11 #include <linux/pkt_sched.h>
  12
  13 static const double a=3.0;
  14 #define TABLESIZE       16384
  15 #define TABLEFACTOR     NETEM_DIST_SCALE
  16
  17 int
  18 main(int argc, char **argv)
  19 {
  20         int i, n;
  21         double dvalue;
  22
  23         printf("# This is the distribution table for the pareto distribution.\n");
  24
  25         for (i = 65536, n = 0; i > 0; i -= 16) {
  26                 dvalue = (double)i/(double)65536;
  27                 dvalue = 1.0/pow(dvalue, 1.0/a);
  28                 dvalue -= 1.5;
  29                 dvalue *= (4.0/3.0)*(double)TABLEFACTOR;
  30                 if (dvalue > 32767)
  31                         dvalue = 32767;
  32
  33                 printf(" %d", (int)rint(dvalue));
  34                 if (++n == 8) {
  35                         putchar('\n');
  36                         n = 0;
  37                 }
  38         }
  39
  40         return 0;
  41 }