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#define RCSID	"$Id$"
21
22#include <stdio.h>
23#include <unistd.h>
24#include <sys/types.h>
25#include <sys/time.h>
26
27#include <pppd.h>
28#include "magic.h"
29
30static const char rcsid[] = RCSID;
31
32extern long mrand48 __P((void));
33extern void srand48 __P((long));
34
35/*
36 * magic_init - Initialize the magic number generator.
37 *
38 * Attempts to compute a random number seed which will not repeat.
39 * The current method uses the current hostid, current process ID
40 * and current time, currently.
41 */
42void
43magic_init()
44{
45    long seed;
46    struct timeval t;
47
48    gettimeofday(&t, NULL);
49    seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid();
50    srand48(seed);
51}
52
53/*
54 * magic - Returns the next magic number.
55 */
56u_int32_t
57magic()
58{
59    return (u_int32_t) mrand48();
60}
61
62#ifdef NO_DRAND48
63/*
64 * Substitute procedures for those systems which don't have
65 * drand48 et al.
66 */
67
68double
69drand48()
70{
71    return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
72}
73
74long
75mrand48()
76{
77    return random();
78}
79
80void
81srand48(seedval)
82long seedval;
83{
84    srandom((int)seedval);
85}
86
87#endif
88