xref: /freebsd/bin/uuidgen/uuidgen.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/capsicum.h>
30 
31 #include <capsicum_helpers.h>
32 #include <err.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36 #include <uuid.h>
37 
38 static void
39 usage(void)
40 {
41 	(void)fprintf(stderr,
42 	    "usage: uuidgen [-1] [-r] [-n count] [-o filename]\n");
43 	exit(1);
44 }
45 
46 static void
47 uuid_to_compact_string(const uuid_t *u, char **s, uint32_t *status)
48 {
49 	uuid_t nil;
50 
51 	if (status != NULL)
52 		*status = uuid_s_ok;
53 
54 	if (s == NULL)
55 		return;
56 
57 	if (u == NULL) {
58 		u = &nil;
59 		uuid_create_nil(&nil, NULL);
60 	}
61 
62 	asprintf(s, "%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x",
63 	    u->time_low, u->time_mid, u->time_hi_and_version,
64 	    u->clock_seq_hi_and_reserved, u->clock_seq_low, u->node[0],
65 	    u->node[1], u->node[2], u->node[3], u->node[4], u->node[5]);
66 
67 	if (*s == NULL && status != NULL)
68 		*status = uuid_s_no_memory;
69 }
70 
71 static int
72 uuidgen_v4(struct uuid *store, int count)
73 {
74 	int size;
75 	struct uuid *item;
76 
77 	if (count < 1) {
78 		errno = EINVAL;
79 		return (-1);
80 	}
81 	size = sizeof(struct uuid) * count;
82 	arc4random_buf(store, size);
83 	item = store;
84 	for (int i = 0; i < count; ++i) {
85 		/*
86 		 * Set the two most significant bits (bits 6 and 7) of the
87 		 * clock_seq_hi_and_reserved to zero and one, respectively.
88 		 */
89 		item->clock_seq_hi_and_reserved &= ~(3 << 6);
90 		item->clock_seq_hi_and_reserved |= (2 << 6);
91 		/*
92 		 * Set the four most significant bits (bits 12 through 15) of
93 		 * the time_hi_and_version field to the 4-bit version number
94 		 * from  Section 4.1.3.
95 		 */
96 		item->time_hi_and_version &= ~(15 << 12);
97 		item->time_hi_and_version |= (4 << 12);
98 		item++;
99 	};
100 	return (0);
101 }
102 
103 int
104 main(int argc, char *argv[])
105 {
106 	FILE *fp;
107 	uuid_t *store, *uuid;
108 	char *p;
109 	int ch, count, i, iterate, status, version;
110 	void (*tostring)(const uuid_t *, char **, uint32_t *) = uuid_to_string;
111 
112 	count = -1;  /* no count yet */
113 	fp = stdout; /* default output file */
114 	iterate = 0; /* not one at a time */
115 	version = 1; /* create uuid v1 by default */
116 	while ((ch = getopt(argc, argv, "1crn:o:")) != -1)
117 		switch (ch) {
118 		case '1':
119 			iterate = 1;
120 			break;
121 		case 'c':
122 			tostring = uuid_to_compact_string;
123 			break;
124 		case 'r':
125 			version = 4;
126 			break;
127 		case 'n':
128 			if (count > 0)
129 				usage();
130 			count = strtol(optarg, &p, 10);
131 			if (*p != 0 || count < 1)
132 				usage();
133 			break;
134 		case 'o':
135 			if (fp != stdout)
136 				errx(1, "multiple output files not allowed");
137 			fp = fopen(optarg, "w");
138 			if (fp == NULL)
139 				err(1, "fopen");
140 			break;
141 		default:
142 			usage();
143 		}
144 	argv += optind;
145 	argc -= optind;
146 
147 	if (argc)
148 		usage();
149 
150 	caph_cache_catpages();
151 	if (caph_limit_stdio() < 0)
152 		err(1, "Unable to limit stdio");
153 	if (caph_enter() < 0)
154 		err(1, "Unable to enter capability mode");
155 
156 	if (count == -1)
157 		count = 1;
158 
159 	store = (uuid_t *)malloc(sizeof(uuid_t) * count);
160 	if (store == NULL)
161 		err(1, "malloc()");
162 
163 	if (!iterate) {
164 		/* Get them all in a single batch */
165 		if (version == 1) {
166 			if (uuidgen(store, count) != 0)
167 				err(1, "uuidgen()");
168 		} else if (version == 4) {
169 			if (uuidgen_v4(store, count) != 0)
170 				err(1, "uuidgen_v4()");
171 		} else {
172 			err(1, "unsupported version");
173 		}
174 	} else {
175 		uuid = store;
176 		for (i = 0; i < count; i++) {
177 			if (version == 1) {
178 				if (uuidgen(uuid++, 1) != 0)
179 					err(1, "uuidgen()");
180 			} else if (version == 4) {
181 				if (uuidgen_v4(uuid++, 1) != 0)
182 					err(1, "uuidgen_v4()");
183 			} else {
184 				err(1, "unsupported version");
185 			}
186 		}
187 	}
188 
189 	uuid = store;
190 	while (count--) {
191 		tostring(uuid++, &p, &status);
192 		if (status != uuid_s_ok)
193 			err(1, "cannot stringify a UUID");
194 		fprintf(fp, "%s\n", p);
195 		free(p);
196 	}
197 
198 	free(store);
199 	if (fp != stdout)
200 		fclose(fp);
201 	return (0);
202 }
203