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