1 /*
2 * magic.c - PPP Magic Number routines.
3 *
4 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * 3. The name "Carnegie Mellon University" must not be used to
19 * endorse or promote products derived from this software without
20 * prior written permission. For permission or any legal
21 * details, please contact
22 * Office of Technology Transfer
23 * Carnegie Mellon University
24 * 5000 Forbes Avenue
25 * Pittsburgh, PA 15213-3890
26 * (412) 268-4387, fax: (412) 268-7395
27 * tech-transfer@andrew.cmu.edu
28 *
29 * 4. Redistributions of any form whatsoever must retain the following
30 * acknowledgment:
31 * "This product includes software developed by Computing Services
32 * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
33 *
34 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
35 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
36 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
37 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
38 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
39 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
40 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41 */
42
43 #define RCSID "$Id: magic.c,v 1.11 2003/06/11 23:56:26 paulus Exp $"
44
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <sys/types.h>
49 #include <sys/time.h>
50
51 #include "pppd.h"
52 #include "magic.h"
53
54 static const char rcsid[] = RCSID;
55
56 extern long mrand48 __P((void));
57 extern void srand48 __P((long));
58
59 /*
60 * magic_init - Initialize the magic number generator.
61 *
62 * Attempts to compute a random number seed which will not repeat.
63 * The current method uses the current hostid, current process ID
64 * and current time, currently.
65 */
66 void
magic_init()67 magic_init()
68 {
69 long seed;
70 struct timeval t;
71
72 gettimeofday(&t, NULL);
73 seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid();
74 srand48(seed);
75 }
76
77 /*
78 * magic - Returns the next magic number.
79 */
80 u_int32_t
magic()81 magic()
82 {
83 return (u_int32_t) mrand48();
84 }
85
86 /*
87 * random_bytes - Fill a buffer with random bytes.
88 */
89 void
random_bytes(unsigned char * buf,int len)90 random_bytes(unsigned char *buf, int len)
91 {
92 int i;
93
94 for (i = 0; i < len; ++i)
95 buf[i] = mrand48() >> 24;
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
drand48()105 drand48()
106 {
107 return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
108 }
109
110 long
mrand48()111 mrand48()
112 {
113 return random();
114 }
115
116 void
srand48(seedval)117 srand48(seedval)
118 long seedval;
119 {
120 srandom((int)seedval);
121 }
122
123 #endif
124