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/*
* magic.c - PPP Magic Number routines.
*
* Copyright (c) 1989 Carnegie Mellon University.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Carnegie Mellon University. The name of the
* University 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 WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char rcsid[] = "$Id: magic.c,v 1.2.6.1 1996/03/01 19:34:52 phk Exp $";
#endif
#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include "magic.h"
static u_long next; /* Next value to return */
extern u_long gethostid __P((void));
extern long random __P((void));
extern void srandom __P((int));
/*
* magic_init - Initialize the magic number generator.
*
* Computes first magic number and seed for random number generator.
* Attempts to compute a random number seed which will not repeat.
* The current method uses the current hostid and current time.
*/
void magic_init()
{
struct timeval tv;
next = gethostid();
if (gettimeofday(&tv, NULL)) {
perror("gettimeofday");
exit(1);
}
next ^= (u_long) tv.tv_sec ^ (u_long) tv.tv_usec;
srandom((int) next);
}
/*
* magic - Returns the next magic number.
*/
u_long magic()
{
u_long m;
m = next;
next = (u_long) random();
return (m);
}
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