iconvdata/unicode.c

   1 /* Conversion module for Unicode
   2    Copyright (C) 1999-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <byteswap.h>
  21 #include <dlfcn.h>
  22 #include <gconv.h>
  23 #include <stddef.h>
  24 #include <stdint.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 /* This is the Byte Order Mark character (BOM).  */
  29 #define BOM     0xfeff
  30 /* And in the other endian format.  */
  31 #define BOM_OE  0xfffe
  32
  33
  34 /* Definitions used in the body of the `gconv' function.  */
  35 #define FROM_LOOP               from_unicode_loop
  36 #define TO_LOOP                 to_unicode_loop
  37 #define DEFINE_INIT             0
  38 #define DEFINE_FINI             0
  39 #define MIN_NEEDED_FROM         2
  40 #define MIN_NEEDED_TO           4
  41 #define ONE_DIRECTION           0
  42 #define FROM_DIRECTION          (dir == from_unicode)
  43 #define PREPARE_LOOP \
  44   enum direction dir = ((struct unicode_data *) step->__data)->dir;           \
  45   int swap;                                                                   \
  46   if (FROM_DIRECTION)                                                         \
  47     {                                                                         \
  48       if (data->__invocation_counter == 0)                                    \
  49         {                                                                     \
  50           /* We have to find out which byte order the file is encoded in.  */ \
  51           if (inptr + 2 > inend)                                              \
  52             return (inptr == inend                                            \
  53                     ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);        \
  54                                                                               \
  55           if (get16u (inptr) == BOM)                                          \
  56             /* Simply ignore the BOM character.  */                           \
  57             *inptrp = inptr += 2;                                             \
  58           else if (get16u (inptr) == BOM_OE)                                  \
  59             {                                                                 \
  60               data->__flags |= __GCONV_SWAP;                                  \
  61               *inptrp = inptr += 2;                                           \
  62             }                                                                 \
  63         }                                                                     \
  64     }                                                                         \
  65   else if (!data->__internal_use && data->__invocation_counter == 0)          \
  66     {                                                                         \
  67       /* Emit the Byte Order Mark.  */                                        \
  68       if (__glibc_unlikely (outbuf + 2 > outend))                             \
  69         return __GCONV_FULL_OUTPUT;                                           \
  70                                                                               \
  71       put16u (outbuf, BOM);                                                   \
  72       outbuf += 2;                                                            \
  73     }                                                                         \
  74   swap = data->__flags & __GCONV_SWAP;
  75 #define EXTRA_LOOP_ARGS         , swap
  76
  77
  78 /* Direction of the transformation.  */
  79 enum direction
  80 {
  81   illegal_dir,
  82   to_unicode,
  83   from_unicode
  84 };
  85
  86 struct unicode_data
  87 {
  88   enum direction dir;
  89 };
  90
  91
  92 extern int gconv_init (struct __gconv_step *step);
  93 int
  94 gconv_init (struct __gconv_step *step)
  95 {
  96   /* Determine which direction.  */
  97   struct unicode_data *new_data;
  98   enum direction dir = illegal_dir;
  99   int result;
 100
 101   if (strcmp (step->__from_name, "UNICODE//") == 0)
 102     dir = from_unicode;
 103   else
 104     dir = to_unicode;
 105
 106   new_data = (struct unicode_data *) malloc (sizeof (struct unicode_data));
 107
 108   result = __GCONV_NOMEM;
 109   if (new_data != NULL)
 110     {
 111       new_data->dir = dir;
 112       step->__data = new_data;
 113
 114       if (dir == from_unicode)
 115         {
 116           step->__min_needed_from = MIN_NEEDED_FROM;
 117           step->__max_needed_from = MIN_NEEDED_FROM;
 118           step->__min_needed_to = MIN_NEEDED_TO;
 119           step->__max_needed_to = MIN_NEEDED_TO;
 120         }
 121       else
 122         {
 123           step->__min_needed_from = MIN_NEEDED_TO;
 124           step->__max_needed_from = MIN_NEEDED_TO;
 125           step->__min_needed_to = MIN_NEEDED_FROM;
 126           step->__max_needed_to = MIN_NEEDED_FROM;
 127         }
 128
 129       step->__stateful = 0;
 130
 131       result = __GCONV_OK;
 132     }
 133
 134   return result;
 135 }
 136
 137
 138 extern void gconv_end (struct __gconv_step *data);
 139 void
 140 gconv_end (struct __gconv_step *data)
 141 {
 142   free (data->__data);
 143 }
 144
 145
 146 /* Convert from the internal (UCS4-like) format to UCS2.  */
 147 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
 148 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
 149 #define LOOPFCT                 TO_LOOP
 150 #define BODY \
 151   {                                                                           \
 152     uint32_t c = get32 (inptr);                                               \
 153                                                                               \
 154     if (__glibc_unlikely (c >= 0x10000))                                      \
 155       {                                                                       \
 156         UNICODE_TAG_HANDLER (c, 4);                                           \
 157         STANDARD_TO_LOOP_ERR_HANDLER (4);                                     \
 158       }                                                                       \
 159     else if (__glibc_unlikely (c >= 0xd800 && c < 0xe000))                    \
 160       {                                                                       \
 161         /* Surrogate characters in UCS-4 input are not valid.                 \
 162            We must catch this, because the UCS-2 output might be              \
 163            interpreted as UTF-16 by other programs.  If we let                \
 164            surrogates pass through, attackers could make a security           \
 165            hole exploit by synthesizing any desired plane 1-16                \
 166            character.  */                                                     \
 167         result = __GCONV_ILLEGAL_INPUT;                                       \
 168         if (! ignore_errors_p ())                                             \
 169           break;                                                              \
 170         inptr += 4;                                                           \
 171         ++*irreversible;                                                      \
 172         continue;                                                             \
 173       }                                                                       \
 174     else                                                                      \
 175       {                                                                       \
 176         put16 (outptr, c);                                                    \
 177         outptr += 2;                                                          \
 178       }                                                                       \
 179                                                                               \
 180     inptr += 4;                                                               \
 181   }
 182 #define LOOP_NEED_FLAGS
 183 #define EXTRA_LOOP_DECLS \
 184         , int swap
 185 #include <iconv/loop.c>
 186
 187
 188 /* Convert from UCS2 to the internal (UCS4-like) format.  */
 189 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
 190 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
 191 #define LOOPFCT                 FROM_LOOP
 192 #define BODY \
 193   {                                                                           \
 194     uint16_t u1 = get16 (inptr);                                              \
 195                                                                               \
 196     if (swap)                                                                 \
 197       u1 = bswap_16 (u1);                                                     \
 198                                                                               \
 199     if (__glibc_unlikely (u1 >= 0xd800 && u1 < 0xe000))                       \
 200       {                                                                       \
 201         /* Surrogate characters in UCS-2 input are not valid.  Reject         \
 202            them.  (Catching this here is not security relevant.)  */          \
 203         STANDARD_FROM_LOOP_ERR_HANDLER (2);                                   \
 204       }                                                                       \
 205                                                                               \
 206     put32 (outptr, u1);                                                       \
 207                                                                               \
 208     inptr += 2;                                                               \
 209     outptr += 4;                                                              \
 210   }
 211 #define LOOP_NEED_FLAGS
 212 #define EXTRA_LOOP_DECLS \
 213         , int swap
 214 #include <iconv/loop.c>
 215
 216
 217 /* Now define the toplevel functions.  */
 218 #include <iconv/skeleton.c>