lib/ext2fs/nls_utf8.c

   1 /*
   2  * Copyright (c) 2018 Collabora Ltd.
   3  * All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 /*
  17  * This code is adapted from the Linux Kernel.  We have a
  18  * userspace version here such that the hashes will match that
  19  * implementation.
  20  */
  21
  22 #include "nls.h"
  23 #include "utf8n.h"
  24
  25 #include <limits.h>
  26 #include <errno.h>
  27
  28 static int utf8_casefold(const struct nls_table *table,
  29                           const unsigned char *str, size_t len,
  30                           unsigned char *dest, size_t dlen)
  31 {
  32         const struct utf8data *data = utf8nfdicf(table->version);
  33         struct utf8cursor cur;
  34         size_t nlen = 0;
  35
  36         if (utf8ncursor(&cur, data, str, len) < 0)
  37                 goto invalid_seq;
  38
  39         for (nlen = 0; nlen < dlen; nlen++) {
  40                 dest[nlen] = utf8byte(&cur);
  41                 if (!dest[nlen])
  42                         return nlen;
  43                 if (dest[nlen] == -1)
  44                         break;
  45         }
  46
  47         return -ENAMETOOLONG;
  48
  49 invalid_seq:
  50         if (dlen < len)
  51                 return -ENAMETOOLONG;
  52
  53         /* Signal invalid sequence */
  54         return -EINVAL;
  55 }
  56
  57 const static struct nls_ops utf8_ops = {
  58         .casefold = utf8_casefold,
  59 };
  60
  61 const struct nls_table nls_utf8_12_1 = {
  62         .ops = &utf8_ops,
  63         .version = UNICODE_AGE(12, 1, 0),
  64 };