xref: /aosp_15_r20/external/e2fsprogs/lib/uuid/uuid_time.c (revision 6a54128f25917bfc36a8a6e9d722c04a0b4641b6)
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 "config.h"
38 
39 #include <stdio.h>
40 #ifdef HAVE_UNISTD_H
41 #include <unistd.h>
42 #endif
43 #include <stdlib.h>
44 #include <sys/types.h>
45 #ifdef HAVE_SYS_TIME_H
46 #include <sys/time.h>
47 #endif
48 #include <time.h>
49 
50 #include "uuidP.h"
51 
uuid_time(const uuid_t uu,struct timeval * ret_tv)52 time_t uuid_time(const uuid_t uu, struct timeval *ret_tv)
53 {
54 	struct timeval		tv;
55 	struct uuid		uuid;
56 	uint32_t		high;
57 	uint64_t		clock_reg;
58 
59 	uuid_unpack(uu, &uuid);
60 
61 	high = uuid.time_mid | ((uuid.time_hi_and_version & 0xFFF) << 16);
62 	clock_reg = uuid.time_low | ((uint64_t) high << 32);
63 
64 	clock_reg -= (((uint64_t) 0x01B21DD2) << 32) + 0x13814000;
65 	tv.tv_sec = clock_reg / 10000000;
66 	tv.tv_usec = (clock_reg % 10000000) / 10;
67 
68 	if (ret_tv)
69 		*ret_tv = tv;
70 
71 	return tv.tv_sec;
72 }
73 
uuid_type(const uuid_t uu)74 int uuid_type(const uuid_t uu)
75 {
76 	struct uuid		uuid;
77 
78 	uuid_unpack(uu, &uuid);
79 	return ((uuid.time_hi_and_version >> 12) & 0xF);
80 }
81 
uuid_variant(const uuid_t uu)82 int uuid_variant(const uuid_t uu)
83 {
84 	struct uuid		uuid;
85 	int			var;
86 
87 	uuid_unpack(uu, &uuid);
88 	var = uuid.clock_seq;
89 
90 	if ((var & 0x8000) == 0)
91 		return UUID_VARIANT_NCS;
92 	if ((var & 0x4000) == 0)
93 		return UUID_VARIANT_DCE;
94 	if ((var & 0x2000) == 0)
95 		return UUID_VARIANT_MICROSOFT;
96 	return UUID_VARIANT_OTHER;
97 }
98 
99 #ifdef DEBUG
variant_string(int variant)100 static const char *variant_string(int variant)
101 {
102 	switch (variant) {
103 	case UUID_VARIANT_NCS:
104 		return "NCS";
105 	case UUID_VARIANT_DCE:
106 		return "DCE";
107 	case UUID_VARIANT_MICROSOFT:
108 		return "Microsoft";
109 	default:
110 		return "Other";
111 	}
112 }
113 
114 
115 int
main(int argc,char ** argv)116 main(int argc, char **argv)
117 {
118 	uuid_t		buf;
119 	time_t		time_reg;
120 	struct timeval	tv;
121 	int		type, variant;
122 
123 	if (argc != 2) {
124 		fprintf(stderr, "Usage: %s uuid\n", argv[0]);
125 		exit(1);
126 	}
127 	if (uuid_parse(argv[1], buf)) {
128 		fprintf(stderr, "Invalid UUID: %s\n", argv[1]);
129 		exit(1);
130 	}
131 	variant = uuid_variant(buf);
132 	type = uuid_type(buf);
133 	time_reg = uuid_time(buf, &tv);
134 
135 	printf("UUID variant is %d (%s)\n", variant, variant_string(variant));
136 	if (variant != UUID_VARIANT_DCE) {
137 		printf("Warning: This program only knows how to interpret "
138 		       "DCE UUIDs.\n\tThe rest of the output is likely "
139 		       "to be incorrect!!\n");
140 	}
141 	printf("UUID type is %d", type);
142 	switch (type) {
143 	case 1:
144 		printf(" (time based)\n");
145 		break;
146 	case 2:
147 		printf(" (DCE)\n");
148 		break;
149 	case 3:
150 		printf(" (name-based)\n");
151 		break;
152 	case 4:
153 		printf(" (random)\n");
154 		break;
155 	default:
156 		printf("\n");
157 	}
158 	if (type != 1) {
159 		printf("Warning: not a time-based UUID, so UUID time "
160 		       "decoding will likely not work!\n");
161 	}
162 	printf("UUID time is: (%ld, %ld): %s\n", (long)tv.tv_sec, (long)tv.tv_usec,
163 	       ctime(&time_reg));
164 
165 	return 0;
166 }
167 #endif
168