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efichar.c revision 1.1.2.2
      1 /*	$NetBSD: efichar.c,v 1.1.2.2 2018/03/30 06:20:11 pgoyette Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 Marcel Moolenaar
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 #if 0
     31 __FBSDID("$FreeBSD: head/stand/efi/libefi/efichar.c 328061 2018-01-16 20:35:54Z tsoome $");
     32 #endif
     33 
     34 #include "efiboot.h"
     35 
     36 size_t
     37 ucs2len(const CHAR16 *str)
     38 {
     39 	size_t i;
     40 
     41 	i = 0;
     42 	while (*str++)
     43 		i++;
     44 	return i;
     45 }
     46 
     47 /*
     48  * If nm were converted to utf8, what what would strlen
     49  * return on the resulting string?
     50  */
     51 static size_t
     52 utf8_len_of_ucs2(const CHAR16 *nm)
     53 {
     54 	size_t len;
     55 	CHAR16 c;
     56 
     57 	len = 0;
     58 	while (*nm) {
     59 		c = *nm++;
     60 		if (c > 0x7ff)
     61 			len += 3;
     62 		else if (c > 0x7f)
     63 			len += 2;
     64 		else
     65 			len++;
     66 	}
     67 
     68 	return len;
     69 }
     70 
     71 int
     72 ucs2_to_utf8(const CHAR16 *nm, char **name)
     73 {
     74 	size_t len, sz;
     75 	CHAR16 c;
     76 	char *cp;
     77 	int freeit = *name == NULL;
     78 
     79 	sz = utf8_len_of_ucs2(nm) + 1;
     80 	len = 0;
     81 	if (*name != NULL)
     82 		cp = *name;
     83 	else
     84 		cp = *name = AllocatePool(sz);
     85 	if (*name == NULL)
     86 		return ENOMEM;
     87 
     88 	while (*nm) {
     89 		c = *nm++;
     90 		if (c > 0x7ff) {
     91 			if (len++ < sz)
     92 				*cp++ = (char)(0xE0 | (c >> 12));
     93 			if (len++ < sz)
     94 				*cp++ = (char)(0x80 | ((c >> 6) & 0x3f));
     95 			if (len++ < sz)
     96 				*cp++ = (char)(0x80 | (c & 0x3f));
     97 		} else if (c > 0x7f) {
     98 			if (len++ < sz)
     99 				*cp++ = (char)(0xC0 | ((c >> 6) & 0x1f));
    100 			if (len++ < sz)
    101 				*cp++ = (char)(0x80 | (c & 0x3f));
    102 		} else {
    103 			if (len++ < sz)
    104 				*cp++ = (char)(c & 0x7f);
    105 		}
    106 	}
    107 
    108 	if (len >= sz) {
    109 		/* Absent bugs, we'll never return EOVERFLOW */
    110 		if (freeit) {
    111 			FreePool(*name);
    112 			*name = NULL;
    113 		}
    114 		return EOVERFLOW;
    115 	}
    116 	*cp++ = '\0';
    117 
    118 	return 0;
    119 }
    120 
    121 int
    122 utf8_to_ucs2(const char *name, CHAR16 **nmp, size_t *len)
    123 {
    124 	CHAR16 *nm;
    125 	size_t sz;
    126 	uint32_t ucs4;
    127 	int c, bytes;
    128 	int freeit = *nmp == NULL;
    129 
    130 	sz = strlen(name) * 2 + 2;
    131 	if (*nmp == NULL)
    132 		*nmp = AllocatePool(sz);
    133 	if (*nmp == NULL)
    134 		return ENOMEM;
    135 	nm = *nmp;
    136 	*len = sz;
    137 
    138 	ucs4 = 0;
    139 	bytes = 0;
    140 	while (sz > 1 && *name != '\0') {
    141 		c = *name++;
    142 		/*
    143 		 * Conditionalize on the two major character types:
    144 		 * initial and followup characters.
    145 		 */
    146 		if ((c & 0xc0) != 0x80) {
    147 			/* Initial characters. */
    148 			if (bytes != 0)
    149 				goto ilseq;
    150 			if ((c & 0xf8) == 0xf0) {
    151 				ucs4 = c & 0x07;
    152 				bytes = 3;
    153 			} else if ((c & 0xf0) == 0xe0) {
    154 				ucs4 = c & 0x0f;
    155 				bytes = 2;
    156 			} else if ((c & 0xe0) == 0xc0) {
    157 				ucs4 = c & 0x1f;
    158 				bytes = 1;
    159 			} else {
    160 				ucs4 = c & 0x7f;
    161 				bytes = 0;
    162 			}
    163 		} else {
    164 			/* Followup characters. */
    165 			if (bytes > 0) {
    166 				ucs4 = (ucs4 << 6) + (c & 0x3f);
    167 				bytes--;
    168 			} else if (bytes == 0)
    169 				goto ilseq;
    170 		}
    171 		if (bytes == 0) {
    172 			if (ucs4 > 0xffff)
    173 				goto ilseq;
    174 			*nm++ = (CHAR16)ucs4;
    175 			sz -= 2;
    176 		}
    177 	}
    178 	if (sz < 2) {
    179 		if (freeit) {
    180 			FreePool(nm);
    181 			*nmp = NULL;
    182 		}
    183 		return EINVAL;
    184 	}
    185 	sz -= 2;
    186 	*nm = 0;
    187 	*len -= sz;
    188 	return 0;
    189 ilseq:
    190 	if (freeit) {
    191 		FreePool(nm);
    192 		*nmp = NULL;
    193 	}
    194 	return EILSEQ;
    195 }
    196