lib/libefivar/libefivar.c

   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: head/lib/libefivar/libefivar.c 307071 2016-10-11 22:30:41Z imp $");
  29
  30 #include <sys/types.h>
  31 #include <errno.h>
  32 #include <stddef.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36 #include <sys/efi.h>
  37 #include <machine/efi.h>
  38
  39 #include "libefivar_int.h"
  40
  41 #include <stdio.h>
  42
  43 /*
  44  * If nm were converted to utf8, what what would strlen
  45  * return on the resulting string?
  46  */
  47 static size_t
  48 utf8_len_of_ucs2(const efi_char *nm)
  49 {
  50         size_t len;
  51         efi_char c;
  52
  53         len = 0;
  54         while (*nm) {
  55                 c = *nm++;
  56                 if (c > 0x7ff)
  57                         len += 3;
  58                 else if (c > 0x7f)
  59                         len += 2;
  60                 else
  61                         len++;
  62         }
  63
  64         return (len);
  65 }
  66
  67 int
  68 libefi_ucs2_to_utf8(const efi_char *nm, char **name)
  69 {
  70         size_t len, sz;
  71         efi_char c;
  72         char *cp;
  73         int freeit = *name == NULL;
  74
  75         sz = utf8_len_of_ucs2(nm) + 1;
  76         len = 0;
  77         if (*name != NULL)
  78                 cp = *name;
  79         else
  80                 cp = *name = malloc(sz);
  81         if (*name == NULL)
  82                 return (ENOMEM);
  83
  84         while (*nm) {
  85                 c = *nm++;
  86                 if (c > 0x7ff) {
  87                         if (len++ < sz)
  88                                 *cp++ = (char)(0xE0 | (c >> 12));
  89                         if (len++ < sz)
  90                                 *cp++ = (char)(0x80 | ((c >> 6) & 0x3f));
  91                         if (len++ < sz)
  92                                 *cp++ = (char)(0x80 | (c & 0x3f));
  93                 } else if (c > 0x7f) {
  94                         if (len++ < sz)
  95                                 *cp++ = (char)(0xC0 | ((c >> 6) & 0x1f));
  96                         if (len++ < sz)
  97                                 *cp++ = (char)(0x80 | (c & 0x3f));
  98                 } else {
  99                         if (len++ < sz)
 100                                 *cp++ = (char)(c & 0x7f);
 101                 }
 102         }
 103
 104         if (len >= sz) {
 105                 /* Absent bugs, we'll never return EOVERFLOW */
 106                 if (freeit)
 107                         free(*name);
 108                 return (EOVERFLOW);
 109         }
 110         *cp++ = '\0';
 111
 112         return (0);
 113 }
 114
 115 int
 116 libefi_utf8_to_ucs2(const char *name, efi_char **nmp, size_t *len)
 117 {
 118         efi_char *nm;
 119         size_t sz;
 120         uint32_t ucs4;
 121         int c, bytes;
 122         int freeit = *nmp == NULL;
 123
 124         sz = strlen(name) * 2 + 2;
 125         if (*nmp == NULL)
 126                 *nmp = malloc(sz);
 127         nm = *nmp;
 128         *len = sz;
 129
 130         ucs4 = 0;
 131         bytes = 0;
 132         while (sz > 1 && *name != '\0') {
 133                 c = *name++;
 134                 /*
 135                  * Conditionalize on the two major character types:
 136                  * initial and followup characters.
 137                  */
 138                 if ((c & 0xc0) != 0x80) {
 139                         /* Initial characters. */
 140                         if (bytes != 0) {
 141                                 if (freeit)
 142                                         free(nm);
 143                                 return (EILSEQ);
 144                         }
 145                         if ((c & 0xf8) == 0xf0) {
 146                                 ucs4 = c & 0x07;
 147                                 bytes = 3;
 148                         } else if ((c & 0xf0) == 0xe0) {
 149                                 ucs4 = c & 0x0f;
 150                                 bytes = 2;
 151                         } else if ((c & 0xe0) == 0xc0) {
 152                                 ucs4 = c & 0x1f;
 153                                 bytes = 1;
 154                         } else {
 155                                 ucs4 = c & 0x7f;
 156                                 bytes = 0;
 157                         }
 158                 } else {
 159                         /* Followup characters. */
 160                         if (bytes > 0) {
 161                                 ucs4 = (ucs4 << 6) + (c & 0x3f);
 162                                 bytes--;
 163                         } else if (bytes == 0) {
 164                                 if (freeit)
 165                                         free(nm);
 166                                 return (EILSEQ);
 167                         }
 168                 }
 169                 if (bytes == 0) {
 170                         if (ucs4 > 0xffff) {
 171                                 if (freeit)
 172                                         free(nm);
 173                                 return (EILSEQ);
 174                         }
 175                         *nm++ = (efi_char)ucs4;
 176                         sz -= 2;
 177                 }
 178         }
 179         if (sz < 2) {
 180                 if (freeit)
 181                         free(nm);
 182                 return (EDOOFUS);
 183         }
 184         sz -= 2;
 185         *nm = 0;
 186         *len -= sz;
 187         return (0);
 188 }