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
54static const char rcsid[] = RCSID;
55
56extern long mrand48 __P((void));
57extern 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 */
66void
67magic_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 */
80u_int32_t
81magic()
82{
83    return (u_int32_t) mrand48();
84}
85
86/*
87 * random_bytes - Fill a buffer with random bytes.
88 */
89void
90random_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
104double
105drand48()
106{
107    return (double)random() / (double)0x7fffffffL; /* 2**31-1 */
108}
109
110long
111mrand48()
112{
113    return random();
114}
115
116void
117srand48(seedval)
118long seedval;
119{
120    srandom((int)seedval);
121}
122
123#endif
124