1 /* 2 * magic.c - PPP Magic Number routines. 3 * 4 * Copyright (c) 1989 Carnegie Mellon University. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms are permitted 8 * provided that the above copyright notice and this paragraph are 9 * duplicated in all such forms and that any documentation, 10 * advertising materials, and other materials related to such 11 * distribution and use acknowledge that the software was developed 12 * by Carnegie Mellon University. The name of the 13 * University may not be used to endorse or promote products derived 14 * from this software without specific prior written permission. 15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 18 */ 19 20 #pragma ident "%Z%%M% %I% %E% SMI" 21 #define RCSID "$Id: magic.c,v 1.9 1999/08/13 06:46:15 paulus Exp $" 22 23 #include <stdio.h> 24 #include <stdlib.h> 25 #include <unistd.h> 26 #include <sys/types.h> 27 #include <sys/time.h> 28 29 #include "pppd.h" 30 #include "magic.h" 31 32 #if !defined(lint) && !defined(_lint) 33 static const char rcsid[] = RCSID; 34 #endif 35 36 #ifdef NO_DRAND48 37 long mrand48 __P((void)); 38 void srand48 __P((long)); 39 #endif 40 41 /* 42 * magic_init - Initialize the magic number generator. 43 * 44 * Attempts to compute a random number seed which will not repeat. 45 * The current method uses the current hostid, current process ID 46 * and current time, currently. 47 */ 48 void 49 magic_init() 50 { 51 long seed; 52 struct timeval t; 53 54 (void) gettimeofday(&t, NULL); 55 seed = get_host_seed() ^ t.tv_sec ^ t.tv_usec ^ getpid(); 56 srand48(seed); 57 } 58 59 /* 60 * magic - Returns the next magic number. 61 */ 62 u_int32_t 63 magic() 64 { 65 return (u_int32_t) mrand48(); 66 } 67 68 #ifdef NO_DRAND48 69 /* 70 * Substitute procedures for those systems which don't have 71 * drand48 et al. 72 */ 73 74 double 75 drand48() 76 { 77 return (double)random() / (double)0x7fffffffL; /* 2**31-1 */ 78 } 79 80 long 81 mrand48() 82 { 83 return random(); 84 } 85 86 void 87 srand48(seedval) 88 long seedval; 89 { 90 srandom((int)seedval); 91 } 92 93 #endif 94