xref: /freebsd/lib/libc/uuid/uuid_from_string.c (revision 02e9120893770924227138ba49df1edb3896112a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2002 Marcel Moolenaar
5  * Copyright (c) 2002 Hiten Mahesh Pandya
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <stdio.h>
31 #include <string.h>
32 #include <uuid.h>
33 
34 /*
35  * uuid_from_string() - convert a string representation of an UUID into
36  *			a binary representation.
37  * See also:
38  *	http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
39  *
40  * NOTE: The sequence field is in big-endian, while the time fields are in
41  *	 native byte order.
42  */
43 void
44 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
45 {
46 	int n;
47 
48 	/* Short-circuit 2 special cases: NULL pointer and empty string. */
49 	if (s == NULL || *s == '\0') {
50 		uuid_create_nil(u, status);
51 		return;
52 	}
53 
54 	/* Assume the worst. */
55 	if (status != NULL)
56 		*status = uuid_s_invalid_string_uuid;
57 
58 	/* The UUID string representation has a fixed length. */
59 	if (strlen(s) != 36)
60 		return;
61 
62 	/*
63 	 * We only work with "new" UUIDs. New UUIDs have the form:
64 	 *	01234567-89ab-cdef-0123-456789abcdef
65 	 * The so called "old" UUIDs, which we don't support, have the form:
66 	 *	0123456789ab.cd.ef.01.23.45.67.89.ab
67 	 */
68 	if (s[8] != '-')
69 		return;
70 
71 	n = sscanf(s,
72 	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
73 	    &u->time_low, &u->time_mid, &u->time_hi_and_version,
74 	    &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
75 	    &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);
76 
77 	/* Make sure we have all conversions. */
78 	if (n != 11)
79 		return;
80 
81 	/* We have a successful scan. Check semantics... */
82 	n = u->clock_seq_hi_and_reserved;
83 	if ((n & 0x80) != 0x00 &&			/* variant 0? */
84 	    (n & 0xc0) != 0x80 &&			/* variant 1? */
85 	    (n & 0xe0) != 0xc0) {			/* variant 2? */
86 		if (status != NULL)
87 			*status = uuid_s_bad_version;
88 	} else {
89 		if (status != NULL)
90 			*status = uuid_s_ok;
91 	}
92 }
93