xref: /openbsd/usr.sbin/pppd/magic.c (revision 3d8817e4)
1 /*	$OpenBSD: magic.c,v 1.9 2009/10/27 23:59:53 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 #include <stdio.h>
46 #include <unistd.h>
47 #include <sys/types.h>
48 #include <sys/time.h>
49 #include <stdlib.h>
50 
51 #include "pppd.h"
52 #include "magic.h"
53 
54 extern long mrand48(void);
55 extern void srand48(long);
56 
57 /*
58  * magic_init - Initialize the magic number generator.
59  *
60  * Attempts to compute a random number seed which will not repeat.
61  * The current method uses the current hostid, current process ID
62  * and current time, currently.
63  */
64 void
65 magic_init()
66 {
67 #if 0
68     long seed;
69     struct timeval t;
70 
71     gettimeofday(&t, NULL);
72     seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid();
73     srand48(seed);
74 #endif
75 }
76 
77 /*
78  * magic - Returns the next magic number.
79  */
80 u_int32_t
81 magic()
82 {
83 #if 0
84     return (u_int32_t) mrand48();
85 #else
86     return arc4random();
87 #endif
88 }
89 
90 #ifdef NO_DRAND48
91 /*
92  * Substitute procedures for those systems which don't have
93  * drand48 et al.
94  */
95 
96 double
97 drand48()
98 {
99     return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
100 }
101 
102 long
103 mrand48()
104 {
105     return random();
106 }
107 
108 void
109 srand48(seedval)
110 long seedval;
111 {
112     srandom((int)seedval);
113 }
114 
115 #endif
116