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