xref: /openbsd-src/lib/libc/uuid/uuid_from_string.c (revision 46035553bfdd96e63c94e32da0210227ec2e3cf1)
1 /*	$OpenBSD: uuid_from_string.c,v 1.2 2015/09/10 18:13:46 guenther Exp $	*/
2 /*	$NetBSD: uuid_from_string.c,v 1.1 2004/09/13 21:44:54 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 2002 Marcel Moolenaar
6  * Copyright (c) 2002 Hiten Mahesh Pandya
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD: src/lib/libc/uuid/uuid_from_string.c,v 1.2 2003/08/08 19:18:43 marcel Exp $
31  */
32 
33 #include <stdio.h>
34 #include <string.h>
35 #include <uuid.h>
36 
37 /*
38  * uuid_from_string() - convert a string representation of an UUID into
39  *			a binary representation.
40  * See also:
41  *	http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
42  *
43  * NOTE: The sequence field is in big-endian, while the time fields are in
44  *	 native byte order.
45  */
46 void
47 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
48 {
49 	int n;
50 
51 	/* Short-circuit 2 special cases: NULL pointer and empty string. */
52 	if (s == NULL || *s == '\0') {
53 		uuid_create_nil(u, status);
54 		return;
55 	}
56 
57 	/* Assume the worst. */
58 	if (status != NULL)
59 		*status = uuid_s_invalid_string_uuid;
60 
61 	/* The UUID string representation has a fixed length. */
62 	if (strlen(s) != UUID_STR_LEN)
63 		return;
64 
65 	/*
66 	 * We only work with "new" UUIDs. New UUIDs have the form:
67 	 *	01234567-89ab-cdef-0123-456789abcdef
68 	 * The so called "old" UUIDs, which we don't support, have the form:
69 	 *	0123456789ab.cd.ef.01.23.45.67.89.ab
70 	 */
71 	if (s[8] != '-')
72 		return;
73 
74 	n = sscanf(s,
75 	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
76 	    &u->time_low, &u->time_mid, &u->time_hi_and_version,
77 	    &u->clock_seq_hi_and_reserved, &u->clock_seq_low, &u->node[0],
78 	    &u->node[1], &u->node[2], &u->node[3], &u->node[4], &u->node[5]);
79 
80 	/* Make sure we have all conversions. */
81 	if (n != 11)
82 		return;
83 
84 	/* We have a successful scan. Check semantics... */
85 	n = u->clock_seq_hi_and_reserved;
86 	if ((n & 0x80) != 0x00 &&			/* variant 0? */
87 	    (n & 0xc0) != 0x80 &&			/* variant 1? */
88 	    (n & 0xe0) != 0xc0) {			/* variant 2? */
89 		if (status != NULL)
90 			*status = uuid_s_bad_version;
91 	} else {
92 		if (status != NULL)
93 			*status = uuid_s_ok;
94 	}
95 }
96