1 /* $NetBSD: magic.c,v 1.5 2021/01/09 16:39:28 christos 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 <sys/cdefs.h> 46 __RCSID("$NetBSD: magic.c,v 1.5 2021/01/09 16:39:28 christos Exp $"); 47 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <unistd.h> 51 #include <sys/types.h> 52 #include <sys/time.h> 53 54 #include "pppd.h" 55 #include "magic.h" 56 57 58 extern long mrand48 (void); 59 extern void srand48 (long); 60 61 /* 62 * magic_init - Initialize the magic number generator. 63 * 64 * Attempts to compute a random number seed which will not repeat. 65 * The current method uses the current hostid, current process ID 66 * and current time, currently. 67 */ 68 void 69 magic_init(void) 70 { 71 long seed; 72 struct timeval t; 73 74 gettimeofday(&t, NULL); 75 seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid(); 76 srand48(seed); 77 } 78 79 /* 80 * magic - Returns the next magic number. 81 */ 82 u_int32_t 83 magic(void) 84 { 85 return (u_int32_t) mrand48(); 86 } 87 88 /* 89 * random_bytes - Fill a buffer with random bytes. 90 */ 91 void 92 random_bytes(unsigned char *buf, int len) 93 { 94 int i; 95 96 for (i = 0; i < len; ++i) 97 buf[i] = mrand48() >> 24; 98 } 99 100 #ifdef NO_DRAND48 101 /* 102 * Substitute procedures for those systems which don't have 103 * drand48 et al. 104 */ 105 106 double 107 drand48(void) 108 { 109 return (double)random() / (double)0x7fffffffL; /* 2**31-1 */ 110 } 111 112 long 113 mrand48(void) 114 { 115 return random(); 116 } 117 118 void 119 srand48(long seedval) 120 { 121 srandom((int)seedval); 122 } 123 124 #endif 125