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1 /*
2  * uuid_time.c --- Interpret the time field from a uuid.  This program
3  * 	violates the UUID abstraction barrier by reaching into the guts
4  *	of a UUID and interpreting it.
5  *
6  * Copyright (C) 1998, 1999 Theodore Ts'o.
7  *
8  * %Begin-Header%
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, and the entire permission notice in its entirety,
14  *    including the disclaimer of warranties.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote
19  *    products derived from this software without specific prior
20  *    written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
25  * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
28  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
32  * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
33  * DAMAGE.
34  * %End-Header%
35  */
36 
37 #include <stdio.h>
38 #include <unistd.h>
39 #include <stdlib.h>
40 #include <sys/types.h>
41 #include <sys/time.h>
42 #include <time.h>
43 
44 #include "uuidP.h"
45 
uuid_time(const uuid_t uu,struct timeval * ret_tv)46 time_t uuid_time(const uuid_t uu, struct timeval *ret_tv)
47 {
48 	struct uuid		uuid;
49 	uint32_t			high;
50 	struct timeval		tv;
51 	unsigned long long	clock_reg;
52 
53 	uuid_unpack(uu, &uuid);
54 
55 	high = uuid.time_mid | ((uuid.time_hi_and_version & 0xFFF) << 16);
56 	clock_reg = uuid.time_low | ((unsigned long long) high << 32);
57 
58 	clock_reg -= (((unsigned long long) 0x01B21DD2) << 32) + 0x13814000;
59 	tv.tv_sec = clock_reg / 10000000;
60 	tv.tv_usec = (clock_reg % 10000000) / 10;
61 
62 	if (ret_tv)
63 		*ret_tv = tv;
64 
65 	return tv.tv_sec;
66 }
67 
uuid_type(const uuid_t uu)68 int uuid_type(const uuid_t uu)
69 {
70 	struct uuid		uuid;
71 
72 	uuid_unpack(uu, &uuid);
73 	return ((uuid.time_hi_and_version >> 12) & 0xF);
74 }
75 
uuid_variant(const uuid_t uu)76 int uuid_variant(const uuid_t uu)
77 {
78 	struct uuid		uuid;
79 	int			var;
80 
81 	uuid_unpack(uu, &uuid);
82 	var = uuid.clock_seq;
83 
84 	if ((var & 0x8000) == 0)
85 		return UUID_VARIANT_NCS;
86 	if ((var & 0x4000) == 0)
87 		return UUID_VARIANT_DCE;
88 	if ((var & 0x2000) == 0)
89 		return UUID_VARIANT_MICROSOFT;
90 	return UUID_VARIANT_OTHER;
91 }
92 
93 #ifdef DEBUG
variant_string(int variant)94 static const char *variant_string(int variant)
95 {
96 	switch (variant) {
97 	case UUID_VARIANT_NCS:
98 		return "NCS";
99 	case UUID_VARIANT_DCE:
100 		return "DCE";
101 	case UUID_VARIANT_MICROSOFT:
102 		return "Microsoft";
103 	default:
104 		return "Other";
105 	}
106 }
107 
108 
109 int
main(int argc,char ** argv)110 main(int argc, char **argv)
111 {
112 	uuid_t		buf;
113 	time_t		time_reg;
114 	struct timeval	tv;
115 	int		type, variant;
116 
117 	if (argc != 2) {
118 		fprintf(stderr, "Usage: %s uuid\n", argv[0]);
119 		exit(1);
120 	}
121 	if (uuid_parse(argv[1], buf)) {
122 		fprintf(stderr, "Invalid UUID: %s\n", argv[1]);
123 		exit(1);
124 	}
125 	variant = uuid_variant(buf);
126 	type = uuid_type(buf);
127 	time_reg = uuid_time(buf, &tv);
128 
129 	printf("UUID variant is %d (%s)\n", variant, variant_string(variant));
130 	if (variant != UUID_VARIANT_DCE) {
131 		printf("Warning: This program only knows how to interpret "
132 		       "DCE UUIDs.\n\tThe rest of the output is likely "
133 		       "to be incorrect!!\n");
134 	}
135 	printf("UUID type is %d", type);
136 	switch (type) {
137 	case 1:
138 		printf(" (time based)\n");
139 		break;
140 	case 2:
141 		printf(" (DCE)\n");
142 		break;
143 	case 3:
144 		printf(" (name-based)\n");
145 		break;
146 	case 4:
147 		printf(" (random)\n");
148 		break;
149 	default:
150 		printf("\n");
151 	}
152 	if (type != 1) {
153 		printf("Warning: not a time-based UUID, so UUID time "
154 		       "decoding will likely not work!\n");
155 	}
156 	printf("UUID time is: (%ld, %ld): %s\n", tv.tv_sec, tv.tv_usec,
157 	       ctime(&time_reg));
158 
159 	return 0;
160 }
161 #endif
162