2 * $Id: libnet_prand.c,v 1.1.1.1 2000/05/25 00:28:49 route Exp $
5 * libnet_prand.c - pseudo-random number generation
7 * Copyright (c) 1998 - 2001 Mike D. Schiffman <mike@infonexus.com>
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "../include/config.h"
36 #include "../include/libnet.h"
43 if (gettimeofday(&seed, NULL) == -1)
45 perror("seed_rand: cannot gettimeofday");
50 * More entropy then just seeding with time(2).
52 srandom((unsigned)(seed.tv_sec ^ seed.tv_usec));
58 libnet_get_prand(int mod)
67 return (n % 0x2); /* 0 - 1 */
69 return (n % 0xff); /* 0 - 255 */
71 return (n % 0x7fff); /* 0 - 32767 */
73 return (n % 0xffff); /* 0 - 65535 */
75 return (n % 0x7fffffff); /* 0 - 2147483647 */
77 return (n); /* 0 - 4294967295 */
79 return (0); /* NOTTREACHED */