xref: /illumos-gate/usr/src/boot/libsa/uuid_to_string.c (revision 763f1f5f97e4c16840af2ced98915f0ed0f46616)
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 /*
31  * Note: some comments taken from lib/libc/uuid/uuid_to_string.c
32  * Copyright (c) 2002,2005 Marcel Moolenaar
33  * Copyright (c) 2002 Hiten Mahesh Pandya
34  */
35 
36 #include <stand.h>
37 #include <uuid.h>
38 
39 /*
40  * Dump len characters into *buf from val as hex and update *buf
41  */
42 static void
43 tohex(char **buf, int len, uint32_t val)
44 {
45 	static const char *hexstr = "0123456789abcdef";
46 	char *walker = *buf;
47 	int i;
48 
49 	for (i = len - 1; i >= 0; i--) {
50 		walker[i] = hexstr[val & 0xf];
51 		val >>= 4;
52 	}
53 	*buf = walker + len;
54 }
55 
56 /*
57  * uuid_to_string() - Convert a binary UUID into a string representation.
58  * See also:
59  *	http://www.opengroup.org/onlinepubs/009629399/uuid_to_string.htm
60  *
61  * NOTE: The references given above do not have a status code for when
62  *	 the string could not be allocated. The status code has been
63  *	 taken from the Hewlett-Packard implementation.
64  *
65  * NOTE: we don't support u == NULL for a nil UUID, sorry.
66  *
67  * NOTE: The sequence field is in big-endian, while the time fields are in
68  *	 native byte order.
69  *
70  *	 hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
71  *	 01234567-89ab-cdef-0123-456789abcdef
72  */
73 void
74 uuid_to_string(const uuid_t *u, char **s, uint32_t *status)
75 {
76 	uuid_t nil;
77 	char *w;
78 
79 	if (status != NULL)
80 		*status = uuid_s_ok;
81 	if (s == NULL)	/* Regular version does this odd-ball behavior too */
82 		return;
83 	w = *s = malloc(37);
84 	if (*s == NULL) {
85 		if (status != NULL)
86 			*status = uuid_s_no_memory;
87 		return;
88 	}
89 	if (u == NULL) {
90 		u = &nil;
91 		uuid_create_nil(&nil, NULL);
92 	}
93 	/* native */
94 	tohex(&w, 8, u->time_low);
95 	*w++ = '-';
96 	tohex(&w, 4, u->time_mid);
97 	*w++ = '-';
98 	tohex(&w, 4, u->time_hi_and_version);
99 	*w++ = '-';
100 	/* Big endian, so do a byte at a time */
101 	tohex(&w, 2, u->clock_seq_hi_and_reserved);
102 	tohex(&w, 2, u->clock_seq_low);
103 	*w++ = '-';
104 	tohex(&w, 2, u->node[0]);
105 	tohex(&w, 2, u->node[1]);
106 	tohex(&w, 2, u->node[2]);
107 	tohex(&w, 2, u->node[3]);
108 	tohex(&w, 2, u->node[4]);
109 	tohex(&w, 2, u->node[5]);
110 	*w++ = '\0';
111 }
112