mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-05 09:14:03 +00:00
71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
/*
|
|
* 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 1.1 1993/11/11 03:54:25 paulus 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 __ARGS((void));
|
|
extern long random __ARGS((void));
|
|
extern void srandom __ARGS((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);
|
|
}
|