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
main(int argc,char ** argv)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 }
98