xref: /freebsd/lib/libc/uuid/uuid_from_string.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
30  */
31 
32 #include <stdio.h>
33 #include <string.h>
34 #include <uuid.h>
35 
36 /*
37  * uuid_from_string() - convert a string representation of an UUID into
38  *			a binary representation.
39  * See also:
40  *	http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
41  *
42  * NOTE: The sequence field is in big-endian, while the time fields are in
43  *	 native byte order.
44  */
45 void
46 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
47 {
48 	int n;
49 
50 	/* Short-circuit 2 special cases: NULL pointer and empty string. */
51 	if (s == NULL || *s == '\0') {
52 		uuid_create_nil(u, status);
53 		return;
54 	}
55 
56 	/* Assume the worst. */
57 	if (status != NULL)
58 		*status = uuid_s_invalid_string_uuid;
59 
60 	/* The UUID string representation has a fixed length. */
61 	if (strlen(s) != 36)
62 		return;
63 
64 	/*
65 	 * We only work with "new" UUIDs. New UUIDs have the form:
66 	 *	01234567-89ab-cdef-0123-456789abcdef
67 	 * The so called "old" UUIDs, which we don't support, have the form:
68 	 *	0123456789ab.cd.ef.01.23.45.67.89.ab
69 	 */
70 	if (s[8] != '-')
71 		return;
72 
73 	n = sscanf(s,
74 	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
75 	    &u->time_low, &u->time_mid, &u->time_hi_and_version,
76 	    &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
77 	    &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);
78 
79 	/* Make sure we have all conversions. */
80 	if (n != 11)
81 		return;
82 
83 	/* We have a successful scan. Check semantics... */
84 	n = u->clock_seq_hi_and_reserved;
85 	if ((n & 0x80) != 0x00 &&			/* variant 0? */
86 	    (n & 0xc0) != 0x80 &&			/* variant 1? */
87 	    (n & 0xe0) != 0xc0) {			/* variant 2? */
88 		if (status != NULL)
89 			*status = uuid_s_bad_version;
90 	} else {
91 		if (status != NULL)
92 			*status = uuid_s_ok;
93 	}
94 }
95