1 /*
2 * The olsr.org Optimized Link-State Routing daemon (olsrd)
3 *
4 * (c) by the OLSR project
5 *
6 * See our Git repository to find out who worked on this file
7 * and thus is a copyright holder on it.
8 *
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * * Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in
19 * the documentation and/or other materials provided with the
20 * distribution.
21 * * Neither the name of olsr.org, olsrd nor the names of its
22 * contributors may be used to endorse or promote products derived
23 * from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
28 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
29 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
31 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
32 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
33 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
35 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 *
38 * Visit http://www.olsr.org for more information.
39 *
40 * If you find this software useful feel free to make a donation
41 * to the project. For more information see the website or contact
42 * the copyright holders.
43 *
44 */
45
46 #ifndef _OLSR_RANDOM_H
47 #define _OLSR_RANDOM_H
48
49 #include <fcntl.h>
50 #include <unistd.h>
51 #include <stdint.h>
52 #include <stdlib.h>
53 #include <time.h>
54
55 #define OLSR_RANDOM_MAX INT32_MAX
56
olsr_random(void)57 static INLINE long int olsr_random(void) {
58 int32_t value;
59 int randomFile;
60
61 #ifdef _WIN32
62 return random();
63 #endif /* _WIN32 */
64
65 randomFile = open("/dev/urandom", O_RDONLY);
66 if (randomFile == -1) {
67 randomFile = open("/dev/random", O_RDONLY);
68 }
69
70 if ((randomFile == -1) || (read(randomFile, &value, sizeof(value)) != sizeof(value))) {
71 value = random();
72 }
73
74 if (randomFile != -1) {
75 close(randomFile);
76 }
77
78 return abs(value);
79 }
80
81 #endif /* _OLSR_RANDOM_H */
82