xref: /freebsd/stand/efi/libefi/efichar.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2010 Marcel Moolenaar
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/types.h>
31 #include <errno.h>
32 #ifdef _STANDALONE
33 #include <stand.h>
34 #else
35 #include <stddef.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <sys/efi.h>
40 #include <machine/efi.h>
41 #endif
42 
43 #include "efichar.h"
44 
45 int
46 ucs2len(const efi_char *str)
47 {
48 	int i;
49 
50 	i = 0;
51 	while (*str++)
52 		i++;
53 	return (i);
54 }
55 
56 /*
57  * If nm were converted to utf8, what what would strlen
58  * return on the resulting string?
59  */
60 static size_t
61 utf8_len_of_ucs2(const efi_char *nm)
62 {
63 	size_t len;
64 	efi_char c;
65 
66 	len = 0;
67 	while (*nm) {
68 		c = *nm++;
69 		if (c > 0x7ff)
70 			len += 3;
71 		else if (c > 0x7f)
72 			len += 2;
73 		else
74 			len++;
75 	}
76 
77 	return (len);
78 }
79 
80 int
81 ucs2_to_utf8(const efi_char *nm, char **name)
82 {
83 	size_t len, sz;
84 	efi_char c;
85 	char *cp;
86 	int freeit = *name == NULL;
87 
88 	sz = utf8_len_of_ucs2(nm) + 1;
89 	len = 0;
90 	if (*name != NULL)
91 		cp = *name;
92 	else
93 		cp = *name = malloc(sz);
94 	if (*name == NULL)
95 		return (ENOMEM);
96 
97 	while (*nm) {
98 		c = *nm++;
99 		if (c > 0x7ff) {
100 			if (len++ < sz)
101 				*cp++ = (char)(0xE0 | (c >> 12));
102 			if (len++ < sz)
103 				*cp++ = (char)(0x80 | ((c >> 6) & 0x3f));
104 			if (len++ < sz)
105 				*cp++ = (char)(0x80 | (c & 0x3f));
106 		} else if (c > 0x7f) {
107 			if (len++ < sz)
108 				*cp++ = (char)(0xC0 | ((c >> 6) & 0x1f));
109 			if (len++ < sz)
110 				*cp++ = (char)(0x80 | (c & 0x3f));
111 		} else {
112 			if (len++ < sz)
113 				*cp++ = (char)(c & 0x7f);
114 		}
115 	}
116 
117 	if (len >= sz) {
118 		/* Absent bugs, we'll never return EOVERFLOW */
119 		if (freeit) {
120 			free(*name);
121 			*name = NULL;
122 		}
123 		return (EOVERFLOW);
124 	}
125 	*cp++ = '\0';
126 
127 	return (0);
128 }
129 
130 int
131 utf8_to_ucs2(const char *name, efi_char **nmp, size_t *len)
132 {
133 	efi_char *nm;
134 	size_t sz;
135 	uint32_t ucs4;
136 	int c, bytes;
137 	int freeit = *nmp == NULL;
138 
139 	sz = strlen(name) * 2 + 2;
140 	if (*nmp == NULL)
141 		*nmp = malloc(sz);
142 	if (*nmp == NULL)
143 		return (ENOMEM);
144 	nm = *nmp;
145 	*len = sz;
146 
147 	ucs4 = 0;
148 	bytes = 0;
149 	while (sz > 1 && *name != '\0') {
150 		c = *name++;
151 		/*
152 		 * Conditionalize on the two major character types:
153 		 * initial and followup characters.
154 		 */
155 		if ((c & 0xc0) != 0x80) {
156 			/* Initial characters. */
157 			if (bytes != 0)
158 				goto ilseq;
159 			if ((c & 0xf8) == 0xf0) {
160 				ucs4 = c & 0x07;
161 				bytes = 3;
162 			} else if ((c & 0xf0) == 0xe0) {
163 				ucs4 = c & 0x0f;
164 				bytes = 2;
165 			} else if ((c & 0xe0) == 0xc0) {
166 				ucs4 = c & 0x1f;
167 				bytes = 1;
168 			} else {
169 				ucs4 = c & 0x7f;
170 				bytes = 0;
171 			}
172 		} else {
173 			/* Followup characters. */
174 			if (bytes > 0) {
175 				ucs4 = (ucs4 << 6) + (c & 0x3f);
176 				bytes--;
177 			} else if (bytes == 0)
178 				goto ilseq;
179 		}
180 		if (bytes == 0) {
181 			if (ucs4 > 0xffff)
182 				goto ilseq;
183 			*nm++ = (efi_char)ucs4;
184 			sz -= 2;
185 		}
186 	}
187 	if (sz < 2) {
188 		if (freeit) {
189 			free(nm);
190 			*nmp = NULL;
191 		}
192 		return (EDOOFUS);
193 	}
194 	sz -= 2;
195 	*nm = 0;
196 	*len -= sz;
197 	return (0);
198 ilseq:
199 	if (freeit) {
200 		free(nm);
201 		*nmp = NULL;
202 	}
203 	return (EILSEQ);
204 }
205