lfsr_test.c revision 1a69a1a78cfaa86f3b68bbc965232b7876d4da2a
/*
* Copyright (C) 1999, 2000 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
#include <config.h>
#include <stdio.h>
#include <isc/lfsr.h>
#include <isc/util.h>
isc_uint32_t state[1024 * 64];
int
main(int argc, char **argv) {
isc_lfsr_t lfsr1, lfsr2;
int i;
isc_uint32_t temp;
UNUSED(argc);
UNUSED(argv);
/*
* Verify that returned values are reproducable.
*/
isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr1, &state[i], 4);
printf("lfsr1: state[%2d] = %08x\n", i, state[i]);
}
isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr1, &temp, 4);
if (state[i] != temp)
printf("lfsr1: state[%2d] = %08x, "
"but new state is %08x\n",
i, state[i], temp);
}
/*
* Now do the same with skipping.
*/
isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr1, &state[i], 4);
isc_lfsr_skip(&lfsr1, 32);
printf("lfsr1: state[%2d] = %08x\n", i, state[i]);
}
isc_lfsr_init(&lfsr1, 0, 32, 0x80000057U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr1, &temp, 4);
isc_lfsr_skip(&lfsr1, 32);
if (state[i] != temp)
printf("lfsr1: state[%2d] = %08x, "
"but new state is %08x\n",
i, state[i], temp);
}
/*
* Try to find the period of the LFSR.
*
* x^16 + x^5 + x^3 + x^2 + 1
*/
isc_lfsr_init(&lfsr2, 0, 16, 0x00008016U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr2, &state[i], 4);
printf("lfsr2: state[%2d] = %08x\n", i, state[i]);
}
isc_lfsr_init(&lfsr2, 0, 16, 0x00008016U, 0, NULL, NULL);
for (i = 0 ; i < 32 ; i++) {
isc_lfsr_generate(&lfsr2, &temp, 4);
if (state[i] != temp)
printf("lfsr2: state[%2d] = %08x, "
"but new state is %08x\n",
i, state[i], temp);
}
return (0);
}