xref: /freebsd/stand/libsa/uuid_from_string.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * Copyright (c) 2015 M. Warner Losh
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * Note: some comments taken from lib/libc/uuid/uuid_from_string.c
31  * Copyright (c) 2002 Marcel Moolenaar
32  * Copyright (c) 2002 Hiten Mahesh Pandya
33  */
34 
35 
36 #include <stand.h>
37 #include <uuid.h>
38 
39 static int
40 hex2int(int ch)
41 {
42 	if (ch >= '0' && ch <= '9')
43 		return ch - '0';
44 	if (ch >= 'a' && ch <= 'f')
45 		return 10 + ch - 'a';
46 	if (ch >= 'A' && ch <= 'F')
47 		return 10 + ch - 'A';
48 	return 16;
49 }
50 
51 static uint32_t
52 fromhex(const char *s, int len, int *ok)
53 {
54 	uint32_t v;
55 	int i, h;
56 
57 	if (!*ok)
58 		return 0;
59 	v = 0;
60 	for (i = 0; i < len; i++) {
61 		h = hex2int(s[i]);
62 		if (h == 16) {
63 			*ok = 0;
64 			return v;
65 		}
66 		v = (v << 4) | h;
67 	}
68 	return v;
69 }
70 
71 /*
72  * uuid_from_string() - convert a string representation of an UUID into
73  *			a binary representation.
74  * See also:
75  *	http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
76  *
77  * NOTE: The sequence field is in big-endian, while the time fields are in
78  *	 native byte order.
79  *
80  * 01234567-89ab-cdef-0123-456789abcdef
81  * 000000000011111111112222222222333333
82  * 012345678901234567890123456789012345
83  *         -    -    -    -
84  * hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
85  *
86  */
87 void
88 uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
89 {
90 	int ok = 1;
91 	int n;
92 
93 	if (s == NULL || *s == '\0') {
94 		uuid_create_nil(u, status);
95 		return;
96 	}
97 
98 	if (status != NULL)
99 		*status = uuid_s_invalid_string_uuid;
100 	if (strlen(s) != 36)
101 		return;
102 	/* Only support new format, check for all the right dashes */
103 	if (s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-')
104 		return;
105 	/* native byte order */
106 	u->time_low                  = fromhex(s     , 8, &ok);
107 	u->time_mid                  = fromhex(s +  9, 4, &ok);
108 	u->time_hi_and_version       = fromhex(s + 14, 4, &ok);
109 	/* Big endian, but presented as a whole number so decode as such */
110 	u->clock_seq_hi_and_reserved = fromhex(s + 19, 2, &ok);
111 	u->clock_seq_low             = fromhex(s + 21, 2, &ok);
112 	u->node[0]                   = fromhex(s + 24, 2, &ok);
113 	u->node[1]                   = fromhex(s + 26, 2, &ok);
114 	u->node[2]                   = fromhex(s + 28, 2, &ok);
115 	u->node[3]                   = fromhex(s + 30, 2, &ok);
116 	u->node[4]                   = fromhex(s + 32, 2, &ok);
117 	u->node[5]                   = fromhex(s + 34, 2, &ok);
118 	if (!ok)
119 		return;
120 
121 	/* We have a successful scan. Check semantics... */
122 	n = u->clock_seq_hi_and_reserved;
123 	if ((n & 0x80) != 0x00 &&			/* variant 0? */
124 	    (n & 0xc0) != 0x80 &&			/* variant 1? */
125 	    (n & 0xe0) != 0xc0) {			/* variant 2? */
126 		if (status != NULL)
127 			*status = uuid_s_bad_version;
128 	} else {
129 		if (status != NULL)
130 			*status = uuid_s_ok;
131 	}
132 }
133