xref: /openbsd/usr.sbin/pppd/magic.c (revision 404b540a)
1 /*	$OpenBSD: magic.c,v 1.8 2002/07/01 19:31:37 deraadt Exp $	*/
2 
3 /*
4  * magic.c - PPP Magic Number routines.
5  *
6  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. The name "Carnegie Mellon University" must not be used to
21  *    endorse or promote products derived from this software without
22  *    prior written permission. For permission or any legal
23  *    details, please contact
24  *      Office of Technology Transfer
25  *      Carnegie Mellon University
26  *      5000 Forbes Avenue
27  *      Pittsburgh, PA  15213-3890
28  *      (412) 268-4387, fax: (412) 268-7395
29  *      tech-transfer@andrew.cmu.edu
30  *
31  * 4. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by Computing Services
34  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35  *
36  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43  */
44 
45 #ifndef lint
46 #if 0
47 static char rcsid[] = "Id: magic.c,v 1.7 1998/03/25 03:07:49 paulus Exp $";
48 #else
49 static char rcsid[] = "$OpenBSD: magic.c,v 1.8 2002/07/01 19:31:37 deraadt Exp $";
50 #endif
51 #endif
52 
53 #include <stdio.h>
54 #include <unistd.h>
55 #include <sys/types.h>
56 #include <sys/time.h>
57 #include <stdlib.h>
58 
59 #include "pppd.h"
60 #include "magic.h"
61 
62 extern long mrand48(void);
63 extern void srand48(long);
64 
65 /*
66  * magic_init - Initialize the magic number generator.
67  *
68  * Attempts to compute a random number seed which will not repeat.
69  * The current method uses the current hostid, current process ID
70  * and current time, currently.
71  */
72 void
73 magic_init()
74 {
75 #if 0
76     long seed;
77     struct timeval t;
78 
79     gettimeofday(&t, NULL);
80     seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid();
81     srand48(seed);
82 #endif
83 }
84 
85 /*
86  * magic - Returns the next magic number.
87  */
88 u_int32_t
89 magic()
90 {
91 #if 0
92     return (u_int32_t) mrand48();
93 #else
94     return arc4random();
95 #endif
96 }
97 
98 #ifdef NO_DRAND48
99 /*
100  * Substitute procedures for those systems which don't have
101  * drand48 et al.
102  */
103 
104 double
105 drand48()
106 {
107     return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
108 }
109 
110 long
111 mrand48()
112 {
113     return random();
114 }
115 
116 void
117 srand48(seedval)
118 long seedval;
119 {
120     srandom((int)seedval);
121 }
122 
123 #endif
124