external/bsd/bind/dist/bin/tests/lfsr_test.c

   1 /*      $NetBSD: lfsr_test.c,v 1.6 2014/12/10 04:37:53 christos Exp $   */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1999-2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: lfsr_test.c,v 1.16 2007/06/19 23:46:59 tbox Exp  */
  21
  22 /*! \file */
  23 #include <config.h>
  24
  25 #include <stdio.h>
  26
  27 #include <isc/lfsr.h>
  28 #include <isc/util.h>
  29
  30 isc_uint32_t state[1024 * 64];
  31
  32 int
  33 main(int argc, char **argv) {
  34         isc_lfsr_t lfsr1, lfsr2;
  35         int i;
  36         isc_uint32_t temp;
  37
  38         UNUSED(argc);
  39         UNUSED(argv);
  40
  41         /*
  42          * Verify that returned values are reproducable.
  43          */
  44         isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
  45         for (i = 0; i < 32; i++) {
  46                 isc_lfsr_generate(&lfsr1, &state[i], 4);
  47                 printf("lfsr1:  state[%2d] = %08x\n", i, state[i]);
  48         }
  49         isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
  50         for (i = 0; i < 32; i++) {
  51                 isc_lfsr_generate(&lfsr1, &temp, 4);
  52                 if (state[i] != temp)
  53                         printf("lfsr1:  state[%2d] = %08x, "
  54                                "but new state is %08x\n",
  55                                i, state[i], temp);
  56         }
  57
  58         /*
  59          * Now do the same with skipping.
  60          */
  61         isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
  62         for (i = 0; i < 32; i++) {
  63                 isc_lfsr_generate(&lfsr1, &state[i], 4);
  64                 isc_lfsr_skip(&lfsr1, 32);
  65                 printf("lfsr1:  state[%2d] = %08x\n", i, state[i]);
  66         }
  67         isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
  68         for (i = 0; i < 32; i++) {
  69                 isc_lfsr_generate(&lfsr1, &temp, 4);
  70                 isc_lfsr_skip(&lfsr1, 32);
  71                 if (state[i] != temp)
  72                         printf("lfsr1:  state[%2d] = %08x, "
  73                                "but new state is %08x\n",
  74                                i, state[i], temp);
  75         }
  76
  77         /*
  78          * Try to find the period of the LFSR.
  79          *
  80          *      x^16 + x^5 + x^3 + x^2 + 1
  81          */
  82         isc_lfsr_init(&lfsr2, 0, 16, 0x00008016U, 0, NULL, NULL);
  83         for (i = 0; i < 32; i++) {
  84                 isc_lfsr_generate(&lfsr2, &state[i], 4);
  85                 printf("lfsr2:  state[%2d] = %08x\n", i, state[i]);
  86         }
  87         isc_lfsr_init(&lfsr2, 0, 16, 0x00008016U, 0, NULL, NULL);
  88         for (i = 0; i < 32; i++) {
  89                 isc_lfsr_generate(&lfsr2, &temp, 4);
  90                 if (state[i] != temp)
  91                         printf("lfsr2:  state[%2d] = %08x, "
  92                                "but new state is %08x\n",
  93                                i, state[i], temp);
  94         }
  95
  96         return (0);
  97 }