xref: /freebsd/bin/uuidgen/uuidgen.c (revision 005cca8361a4932d03bd93fefa998fff69a1e136)
1 /*
2  * Copyright (c) 2002 Marcel Moolenaar
3  * Copyright (c) 2022 Tobias C. Berner
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/capsicum.h>
33 
34 #include <capsicum_helpers.h>
35 #include <err.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <unistd.h>
39 #include <uuid.h>
40 
41 static void
42 usage(void)
43 {
44 	(void)fprintf(stderr,
45 	    "usage: uuidgen [-1] [-r] [-n count] [-o filename]\n");
46 	exit(1);
47 }
48 
49 static void
50 uuid_to_compact_string(const uuid_t *u, char **s, uint32_t *status)
51 {
52 	uuid_t nil;
53 
54 	if (status != NULL)
55 		*status = uuid_s_ok;
56 
57 	if (s == NULL)
58 		return;
59 
60 	if (u == NULL) {
61 		u = &nil;
62 		uuid_create_nil(&nil, NULL);
63 	}
64 
65 	asprintf(s, "%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x",
66 	    u->time_low, u->time_mid, u->time_hi_and_version,
67 	    u->clock_seq_hi_and_reserved, u->clock_seq_low, u->node[0],
68 	    u->node[1], u->node[2], u->node[3], u->node[4], u->node[5]);
69 
70 	if (*s == NULL && status != NULL)
71 		*status = uuid_s_no_memory;
72 }
73 
74 static int
75 uuidgen_v4(struct uuid *store, int count)
76 {
77 	int size;
78 	struct uuid *item;
79 
80 	if (count < 1) {
81 		errno = EINVAL;
82 		return (-1);
83 	}
84 	size = sizeof(struct uuid) * count;
85 	arc4random_buf(store, size);
86 	item = store;
87 	for (int i = 0; i < count; ++i) {
88 		/*
89 		 * Set the two most significant bits (bits 6 and 7) of the
90 		 * clock_seq_hi_and_reserved to zero and one, respectively.
91 		 */
92 		item->clock_seq_hi_and_reserved &= ~(3 << 6);
93 		item->clock_seq_hi_and_reserved |= (2 << 6);
94 		/*
95 		 * Set the four most significant bits (bits 12 through 15) of
96 		 * the time_hi_and_version field to the 4-bit version number
97 		 * from  Section 4.1.3.
98 		 */
99 		item->time_hi_and_version &= ~(15 << 12);
100 		item->time_hi_and_version |= (4 << 12);
101 		item++;
102 	};
103 	return (0);
104 }
105 
106 int
107 main(int argc, char *argv[])
108 {
109 	FILE *fp;
110 	uuid_t *store, *uuid;
111 	char *p;
112 	int ch, count, i, iterate, status, version;
113 	void (*tostring)(const uuid_t *, char **, uint32_t *) = uuid_to_string;
114 
115 	count = -1;  /* no count yet */
116 	fp = stdout; /* default output file */
117 	iterate = 0; /* not one at a time */
118 	version = 1; /* create uuid v1 by default */
119 	while ((ch = getopt(argc, argv, "1crn:o:")) != -1)
120 		switch (ch) {
121 		case '1':
122 			iterate = 1;
123 			break;
124 		case 'c':
125 			tostring = uuid_to_compact_string;
126 			break;
127 		case 'r':
128 			version = 4;
129 			break;
130 		case 'n':
131 			if (count > 0)
132 				usage();
133 			count = strtol(optarg, &p, 10);
134 			if (*p != 0 || count < 1)
135 				usage();
136 			break;
137 		case 'o':
138 			if (fp != stdout)
139 				errx(1, "multiple output files not allowed");
140 			fp = fopen(optarg, "w");
141 			if (fp == NULL)
142 				err(1, "fopen");
143 			break;
144 		default:
145 			usage();
146 		}
147 	argv += optind;
148 	argc -= optind;
149 
150 	if (argc)
151 		usage();
152 
153 	caph_cache_catpages();
154 	if (caph_limit_stdio() < 0)
155 		err(1, "Unable to limit stdio");
156 	if (caph_enter() < 0)
157 		err(1, "Unable to enter capability mode");
158 
159 	if (count == -1)
160 		count = 1;
161 
162 	store = (uuid_t *)malloc(sizeof(uuid_t) * count);
163 	if (store == NULL)
164 		err(1, "malloc()");
165 
166 	if (!iterate) {
167 		/* Get them all in a single batch */
168 		if (version == 1) {
169 			if (uuidgen(store, count) != 0)
170 				err(1, "uuidgen()");
171 		} else if (version == 4) {
172 			if (uuidgen_v4(store, count) != 0)
173 				err(1, "uuidgen_v4()");
174 		} else {
175 			err(1, "unsupported version");
176 		}
177 	} else {
178 		uuid = store;
179 		for (i = 0; i < count; i++) {
180 			if (version == 1) {
181 				if (uuidgen(uuid++, 1) != 0)
182 					err(1, "uuidgen()");
183 			} else if (version == 4) {
184 				if (uuidgen_v4(uuid++, 1) != 0)
185 					err(1, "uuidgen_v4()");
186 			} else {
187 				err(1, "unsupported version");
188 			}
189 		}
190 	}
191 
192 	uuid = store;
193 	while (count--) {
194 		tostring(uuid++, &p, &status);
195 		if (status != uuid_s_ok)
196 			err(1, "cannot stringify a UUID");
197 		fprintf(fp, "%s\n", p);
198 		free(p);
199 	}
200 
201 	free(store);
202 	if (fp != stdout)
203 		fclose(fp);
204 	return (0);
205 }
206