xref: /freebsd/stand/efi/libefi/efichar.c (revision edf8578117e8844e02c0121147f45e4609b30680)
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 #include <sys/types.h>
29 #include <errno.h>
30 #ifdef _STANDALONE
31 #include <stand.h>
32 #else
33 #include <stddef.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <sys/efi.h>
38 #include <machine/efi.h>
39 #endif
40 
41 #include "efichar.h"
42 
43 int
44 ucs2len(const efi_char *str)
45 {
46 	int i;
47 
48 	i = 0;
49 	while (*str++)
50 		i++;
51 	return (i);
52 }
53 
54 /*
55  * If nm were converted to utf8, what what would strlen
56  * return on the resulting string?
57  */
58 static size_t
59 utf8_len_of_ucs2(const efi_char *nm)
60 {
61 	size_t len;
62 	efi_char c;
63 
64 	len = 0;
65 	while (*nm) {
66 		c = *nm++;
67 		if (c > 0x7ff)
68 			len += 3;
69 		else if (c > 0x7f)
70 			len += 2;
71 		else
72 			len++;
73 	}
74 
75 	return (len);
76 }
77 
78 int
79 ucs2_to_utf8(const efi_char *nm, char **name)
80 {
81 	size_t len, sz;
82 	efi_char c;
83 	char *cp;
84 	int freeit = *name == NULL;
85 
86 	sz = utf8_len_of_ucs2(nm) + 1;
87 	len = 0;
88 	if (*name != NULL)
89 		cp = *name;
90 	else
91 		cp = *name = malloc(sz);
92 	if (*name == NULL)
93 		return (ENOMEM);
94 
95 	while (*nm) {
96 		c = *nm++;
97 		if (c > 0x7ff) {
98 			if (len++ < sz)
99 				*cp++ = (char)(0xE0 | (c >> 12));
100 			if (len++ < sz)
101 				*cp++ = (char)(0x80 | ((c >> 6) & 0x3f));
102 			if (len++ < sz)
103 				*cp++ = (char)(0x80 | (c & 0x3f));
104 		} else if (c > 0x7f) {
105 			if (len++ < sz)
106 				*cp++ = (char)(0xC0 | ((c >> 6) & 0x1f));
107 			if (len++ < sz)
108 				*cp++ = (char)(0x80 | (c & 0x3f));
109 		} else {
110 			if (len++ < sz)
111 				*cp++ = (char)(c & 0x7f);
112 		}
113 	}
114 
115 	if (len >= sz) {
116 		/* Absent bugs, we'll never return EOVERFLOW */
117 		if (freeit) {
118 			free(*name);
119 			*name = NULL;
120 		}
121 		return (EOVERFLOW);
122 	}
123 	*cp++ = '\0';
124 
125 	return (0);
126 }
127 
128 int
129 utf8_to_ucs2(const char *name, efi_char **nmp, size_t *len)
130 {
131 	efi_char *nm;
132 	size_t sz;
133 	uint32_t ucs4;
134 	int c, bytes;
135 	int freeit = *nmp == NULL;
136 
137 	sz = strlen(name) * 2 + 2;
138 	if (*nmp == NULL)
139 		*nmp = malloc(sz);
140 	if (*nmp == NULL)
141 		return (ENOMEM);
142 	nm = *nmp;
143 	*len = sz;
144 
145 	ucs4 = 0;
146 	bytes = 0;
147 	while (sz > 1 && *name != '\0') {
148 		c = *name++;
149 		/*
150 		 * Conditionalize on the two major character types:
151 		 * initial and followup characters.
152 		 */
153 		if ((c & 0xc0) != 0x80) {
154 			/* Initial characters. */
155 			if (bytes != 0)
156 				goto ilseq;
157 			if ((c & 0xf8) == 0xf0) {
158 				ucs4 = c & 0x07;
159 				bytes = 3;
160 			} else if ((c & 0xf0) == 0xe0) {
161 				ucs4 = c & 0x0f;
162 				bytes = 2;
163 			} else if ((c & 0xe0) == 0xc0) {
164 				ucs4 = c & 0x1f;
165 				bytes = 1;
166 			} else {
167 				ucs4 = c & 0x7f;
168 				bytes = 0;
169 			}
170 		} else {
171 			/* Followup characters. */
172 			if (bytes > 0) {
173 				ucs4 = (ucs4 << 6) + (c & 0x3f);
174 				bytes--;
175 			} else if (bytes == 0)
176 				goto ilseq;
177 		}
178 		if (bytes == 0) {
179 			if (ucs4 > 0xffff)
180 				goto ilseq;
181 			*nm++ = (efi_char)ucs4;
182 			sz -= 2;
183 		}
184 	}
185 	if (sz < 2) {
186 		if (freeit) {
187 			free(nm);
188 			*nmp = NULL;
189 		}
190 		return (EDOOFUS);
191 	}
192 	sz -= 2;
193 	*nm = 0;
194 	*len -= sz;
195 	return (0);
196 ilseq:
197 	if (freeit) {
198 		free(nm);
199 		*nmp = NULL;
200 	}
201 	return (EILSEQ);
202 }
203