1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * The copyright in this file is taken from the original Leach 29 * & Salz UUID specification, from which this implementation 30 * is derived. 31 */ 32 33 /* 34 * Copyright (c) 1990- 1993, 1996 Open Software Foundation, Inc. 35 * Copyright (c) 1989 by Hewlett-Packard Company, Palo Alto, Ca. & 36 * Digital Equipment Corporation, Maynard, Mass. Copyright (c) 1998 37 * Microsoft. To anyone who acknowledges that this file is provided 38 * "AS IS" without any express or implied warranty: permission to use, 39 * copy, modify, and distribute this file for any purpose is hereby 40 * granted without fee, provided that the above copyright notices and 41 * this notice appears in all source code copies, and that none of the 42 * names of Open Software Foundation, Inc., Hewlett-Packard Company, 43 * or Digital Equipment Corporation be used in advertising or 44 * publicity pertaining to distribution of the software without 45 * specific, written prior permission. Neither Open Software 46 * Foundation, Inc., Hewlett-Packard Company, Microsoft, nor Digital 47 * Equipment Corporation makes any representations about the 48 * suitability of this software for any purpose. 49 */ 50 51 #include <uuid/uuid.h> 52 #include <stdlib.h> 53 #include <strings.h> 54 #include "uuid_misc.h" 55 56 #define UUCMP(u1, u2) if (u1 != u2) return ((u1 < u2) ? -1 : 1) 57 #define UUIDS_PER_TOD_CALL 10 /* tv_usec is multiplied by 10 */ 58 59 void struct_to_string(uuid_t, struct uuid *); 60 void string_to_struct(struct uuid *, uuid_t); 61 void get_system_time(uuid_time_t *); 62 63 /* 64 * Name: get_current_time 65 * 66 * Description: get-current_time -- get time as 60 bit 100ns ticks 67 * since the beginning of unix time. 68 * Compensate for the fact that real clock resolution is 69 * less than 100ns. 70 * 71 * Returns: None. 72 * 73 */ 74 void 75 get_current_time(uuid_time_t *timestamp) 76 { 77 uuid_time_t time_now; 78 static uuid_time_t time_last = 0; 79 static uint16_t uuids_this_tick = 0; 80 int done; 81 82 done = 0; 83 while (!done) { 84 get_system_time(&time_now); 85 86 /* 87 * if clock reading changed since last UUID generated... 88 */ 89 if (time_last != time_now) { 90 /* 91 * reset count of uuids generated with 92 * this clock reading 93 */ 94 uuids_this_tick = 0; 95 done = 1; 96 } else { 97 uuids_this_tick++; 98 if (uuids_this_tick < UUIDS_PER_TOD_CALL) 99 done = 1; 100 } 101 /* 102 * too many UUIDs for this gettimeofday call; spin 103 */ 104 } 105 time_last = time_now; 106 /* 107 * add the count of uuids to low order bits of the clock reading 108 */ 109 *timestamp = time_now + uuids_this_tick; 110 } 111 112 /* 113 * Name: get_random 114 * 115 * Description: Gets a random number. 116 * 117 * Returns: nbytes of random information. 118 * 119 */ 120 uint16_t 121 get_random(void) 122 { 123 static int initted = 0; 124 uuid_time_t time_now; 125 long seed; 126 127 if (!initted) { 128 get_system_time(&time_now); 129 time_now = time_now/UUIDS_PER_TOD_CALL; 130 seed = (unsigned)(((time_now >> 32) ^ time_now)&0xffffffff); 131 srand48(seed); 132 initted = 1; 133 } 134 return (mrand48()); 135 } 136 137 /* 138 * Name: uuid_compare 139 * 140 * Description: Compares 2 uuid strings 141 * 142 * Returns: -1 if u1 < u2, 1 if u1 > u2 and 0 if both are equal 143 */ 144 int 145 uuid_compare(uuid_t uu1, uuid_t uu2) 146 { 147 148 struct uuid uuid1, uuid2; 149 150 string_to_struct(&uuid1, uu1); 151 string_to_struct(&uuid2, uu2); 152 UUCMP(uuid1.time_low, uuid2.time_low); 153 UUCMP(uuid1.time_mid, uuid2.time_mid); 154 UUCMP(uuid1.time_hi_and_version, uuid2.time_hi_and_version); 155 UUCMP(uuid1.clock_seq_hi_and_reserved, uuid2.clock_seq_hi_and_reserved); 156 UUCMP(uuid1.clock_seq_low, uuid2.clock_seq_low); 157 return (memcmp(uuid1.node_addr, uuid2.node_addr, 6)); 158 } 159 160 /* 161 * Name: get_system_time 162 * 163 * Description: system dependent call to get the current system time. 164 * Returned as 100ns ticks since Oct 15, 1582, but 165 * resolution may be less than 100ns. 166 * 167 * Returns: None 168 */ 169 void 170 get_system_time(uuid_time_t *uuid_time) 171 { 172 struct timeval tp; 173 174 (void) gettimeofday(&tp, (struct timezone *)0); 175 176 /* 177 * Offset between UUID formatted times and Unix formatted times. 178 * UUID UTC base time is October 15, 1582. 179 * Unix base time is January 1, 1970. 180 */ 181 *uuid_time = (uint64_t)tp.tv_sec * 10000000; 182 *uuid_time += tp.tv_usec * 10; 183 *uuid_time += 0x01B21DD213814000ULL; 184 } 185