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/*
* Copyright (c) 2000, 2001 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <sys/types.h>
#if defined(TIME_WITH_SYS_TIME) || defined(HAVE_SYS_TIME_H)
# include <sys/time.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif /* HAVE_STDLIB_H */
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
#if defined(TIME_WITH_SYS_TIME) || !defined(HAVE_SYS_TIME_H)
# include <time.h>
#endif
#include <extern.h>
#ifdef HAVE_RANDOM
# define RAND random
# define SRAND srandom
# define SEED_T unsigned int
#elif defined (HAVE_LRAND48)
# define RAND lrand48
# define SRAND srand48
# define SEED_T long
#else
# define RAND rand
# define SRAND srand
# define SEED_T unsigned int
#endif
#ifndef lint
static const char rcsid[] = "$Id: random.c,v 1.4 2001/10/01 00:21:34 millert Exp $";
#endif /* not lint */
#ifdef HAVE_SRANDOMDEV
void
seed_random()
{
srandomdev();
}
#else !HAVE_SRANDOMDEV
#ifdef _PATH_RANDOM
static ssize_t
read_loop(fd, buf, count)
int fd;
void *buf;
size_t count;
{
char *buffer = (char *) buf;
ssize_t offset, block;
offset = 0;
while (count > 0) {
block = read(fd, &buffer[offset], count);
if (block < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
return(block);
} else if (block == 0)
return(offset);
offset += block;
count -= block;
}
return(offset);
}
#endif /* _PATH_RANDOM */
void
seed_random()
{
SEED_T seed;
struct timeval tv;
#ifdef _PATH_RANDOM
int fd;
if ((fd = open(_PATH_RANDOM, O_RDONLY)) != -1 &&
read_loop(fd, &seed, sizeof(seed)) == sizeof(seed)) {
close(fd);
SRAND(seed);
return;
}
#endif /* _PATH_RANDOM */
/* Don't have /dev/random */
/* XXX - check for gettimeofday() and use time() if none? */
gettimeofday(&tv, NULL);
/* Use time of day and process id multiplied by small primes */
seed = (tv.tv_sec % 10000) * 523 + tv.tv_usec * 13 + (getpid() % 1000) * 983;
SRAND(seed);
}
#endif /* !HAVE_SRANDOMDEV */
long
get_random()
{
static int initialized;
if (!initialized) {
seed_random();
initialized = 1;
}
return(RAND());
}
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