1/*
2 * magic.c - PPP Magic Number routines.
3 *
4 * Copyright (c) 1989 Carnegie Mellon University.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by Carnegie Mellon University.  The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20#pragma ident	"%Z%%M%	%I%	%E% SMI"
21#define RCSID	"$Id: magic.c,v 1.9 1999/08/13 06:46:15 paulus Exp $"
22
23#include <stdio.h>
24#include <stdlib.h>
25#include <unistd.h>
26#include <sys/types.h>
27#include <sys/time.h>
28
29#include "pppd.h"
30#include "magic.h"
31
32#if !defined(lint) && !defined(_lint)
33static const char rcsid[] = RCSID;
34#endif
35
36#ifdef NO_DRAND48
37long mrand48 __P((void));
38void srand48 __P((long));
39#endif
40
41/*
42 * magic_init - Initialize the magic number generator.
43 *
44 * Attempts to compute a random number seed which will not repeat.
45 * The current method uses the current hostid, current process ID
46 * and current time, currently.
47 */
48void
49magic_init()
50{
51    long seed;
52    struct timeval t;
53
54    (void) gettimeofday(&t, NULL);
55    seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid();
56    srand48(seed);
57}
58
59/*
60 * magic - Returns the next magic number.
61 */
62u_int32_t
63magic()
64{
65    return (u_int32_t) mrand48();
66}
67
68#ifdef NO_DRAND48
69/*
70 * Substitute procedures for those systems which don't have
71 * drand48 et al.
72 */
73
74double
75drand48()
76{
77    return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
78}
79
80long
81mrand48()
82{
83    return random();
84}
85
86void
87srand48(seedval)
88long seedval;
89{
90    srandom((int)seedval);
91}
92
93#endif
94