xref: /freebsd/bin/uuidgen/uuidgen.c (revision d0b2dbfa)
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 #include <sys/capsicum.h>
31 
32 #include <capsicum_helpers.h>
33 #include <err.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 #include <uuid.h>
38 
39 static void
40 usage(void)
41 {
42 	(void)fprintf(stderr,
43 	    "usage: uuidgen [-1] [-r] [-n count] [-o filename]\n");
44 	exit(1);
45 }
46 
47 static void
48 uuid_to_compact_string(const uuid_t *u, char **s, uint32_t *status)
49 {
50 	uuid_t nil;
51 
52 	if (status != NULL)
53 		*status = uuid_s_ok;
54 
55 	if (s == NULL)
56 		return;
57 
58 	if (u == NULL) {
59 		u = &nil;
60 		uuid_create_nil(&nil, NULL);
61 	}
62 
63 	asprintf(s, "%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x",
64 	    u->time_low, u->time_mid, u->time_hi_and_version,
65 	    u->clock_seq_hi_and_reserved, u->clock_seq_low, u->node[0],
66 	    u->node[1], u->node[2], u->node[3], u->node[4], u->node[5]);
67 
68 	if (*s == NULL && status != NULL)
69 		*status = uuid_s_no_memory;
70 }
71 
72 static int
73 uuidgen_v4(struct uuid *store, int count)
74 {
75 	int size;
76 	struct uuid *item;
77 
78 	if (count < 1) {
79 		errno = EINVAL;
80 		return (-1);
81 	}
82 	size = sizeof(struct uuid) * count;
83 	arc4random_buf(store, size);
84 	item = store;
85 	for (int i = 0; i < count; ++i) {
86 		/*
87 		 * Set the two most significant bits (bits 6 and 7) of the
88 		 * clock_seq_hi_and_reserved to zero and one, respectively.
89 		 */
90 		item->clock_seq_hi_and_reserved &= ~(3 << 6);
91 		item->clock_seq_hi_and_reserved |= (2 << 6);
92 		/*
93 		 * Set the four most significant bits (bits 12 through 15) of
94 		 * the time_hi_and_version field to the 4-bit version number
95 		 * from  Section 4.1.3.
96 		 */
97 		item->time_hi_and_version &= ~(15 << 12);
98 		item->time_hi_and_version |= (4 << 12);
99 		item++;
100 	};
101 	return (0);
102 }
103 
104 int
105 main(int argc, char *argv[])
106 {
107 	FILE *fp;
108 	uuid_t *store, *uuid;
109 	char *p;
110 	int ch, count, i, iterate, status, version;
111 	void (*tostring)(const uuid_t *, char **, uint32_t *) = uuid_to_string;
112 
113 	count = -1;  /* no count yet */
114 	fp = stdout; /* default output file */
115 	iterate = 0; /* not one at a time */
116 	version = 1; /* create uuid v1 by default */
117 	while ((ch = getopt(argc, argv, "1crn:o:")) != -1)
118 		switch (ch) {
119 		case '1':
120 			iterate = 1;
121 			break;
122 		case 'c':
123 			tostring = uuid_to_compact_string;
124 			break;
125 		case 'r':
126 			version = 4;
127 			break;
128 		case 'n':
129 			if (count > 0)
130 				usage();
131 			count = strtol(optarg, &p, 10);
132 			if (*p != 0 || count < 1)
133 				usage();
134 			break;
135 		case 'o':
136 			if (fp != stdout)
137 				errx(1, "multiple output files not allowed");
138 			fp = fopen(optarg, "w");
139 			if (fp == NULL)
140 				err(1, "fopen");
141 			break;
142 		default:
143 			usage();
144 		}
145 	argv += optind;
146 	argc -= optind;
147 
148 	if (argc)
149 		usage();
150 
151 	caph_cache_catpages();
152 	if (caph_limit_stdio() < 0)
153 		err(1, "Unable to limit stdio");
154 	if (caph_enter() < 0)
155 		err(1, "Unable to enter capability mode");
156 
157 	if (count == -1)
158 		count = 1;
159 
160 	store = (uuid_t *)malloc(sizeof(uuid_t) * count);
161 	if (store == NULL)
162 		err(1, "malloc()");
163 
164 	if (!iterate) {
165 		/* Get them all in a single batch */
166 		if (version == 1) {
167 			if (uuidgen(store, count) != 0)
168 				err(1, "uuidgen()");
169 		} else if (version == 4) {
170 			if (uuidgen_v4(store, count) != 0)
171 				err(1, "uuidgen_v4()");
172 		} else {
173 			err(1, "unsupported version");
174 		}
175 	} else {
176 		uuid = store;
177 		for (i = 0; i < count; i++) {
178 			if (version == 1) {
179 				if (uuidgen(uuid++, 1) != 0)
180 					err(1, "uuidgen()");
181 			} else if (version == 4) {
182 				if (uuidgen_v4(uuid++, 1) != 0)
183 					err(1, "uuidgen_v4()");
184 			} else {
185 				err(1, "unsupported version");
186 			}
187 		}
188 	}
189 
190 	uuid = store;
191 	while (count--) {
192 		tostring(uuid++, &p, &status);
193 		if (status != uuid_s_ok)
194 			err(1, "cannot stringify a UUID");
195 		fprintf(fp, "%s\n", p);
196 		free(p);
197 	}
198 
199 	free(store);
200 	if (fp != stdout)
201 		fclose(fp);
202 	return (0);
203 }
204