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 } 98