iconvdata/utf-32.c

   1 /* Conversion module for UTF-32.
   2    Copyright (C) 1999-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <byteswap.h>
  20 #include <dlfcn.h>
  21 #include <gconv.h>
  22 #include <stddef.h>
  23 #include <stdint.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 /* This is the Byte Order Mark character (BOM).  */
  28 #define BOM     0x0000feffu
  29 /* And in the other byte order.  */
  30 #define BOM_OE  0xfffe0000u
  31
  32
  33 /* Definitions used in the body of the `gconv' function.  */
  34 #define FROM_LOOP               from_utf32_loop
  35 #define TO_LOOP                 to_utf32_loop
  36 #define DEFINE_INIT             0
  37 #define DEFINE_FINI             0
  38 #define MIN_NEEDED_FROM         4
  39 #define MIN_NEEDED_TO           4
  40 #define ONE_DIRECTION           0
  41 #define FROM_DIRECTION          (dir == from_utf32)
  42 #define PREPARE_LOOP \
  43   enum direction dir = ((struct utf32_data *) step->__data)->dir;             \
  44   enum variant var = ((struct utf32_data *) step->__data)->var;               \
  45   int swap;                                                                   \
  46   if (FROM_DIRECTION && var == UTF_32)                                        \
  47     {                                                                         \
  48       if (__glibc_unlikely (data->__invocation_counter == 0))                 \
  49         {                                                                     \
  50           /* We have to find out which byte order the file is encoded in.  */ \
  51           if (inptr + 4 > inend)                                              \
  52             return (inptr == inend                                            \
  53                     ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);        \
  54                                                                               \
  55           if (get32u (inptr) == BOM)                                          \
  56             /* Simply ignore the BOM character.  */                           \
  57             *inptrp = inptr += 4;                                             \
  58           else if (get32u (inptr) == BOM_OE)                                  \
  59             {                                                                 \
  60               data->__flags |= __GCONV_SWAP;                                  \
  61               *inptrp = inptr += 4;                                           \
  62             }                                                                 \
  63         }                                                                     \
  64     }                                                                         \
  65   else if (!FROM_DIRECTION && var == UTF_32 && !data->__internal_use          \
  66            && data->__invocation_counter == 0)                                \
  67     {                                                                         \
  68       /* Emit the Byte Order Mark.  */                                        \
  69       if (__glibc_unlikely (outbuf + 4 > outend))                             \
  70         return __GCONV_FULL_OUTPUT;                                           \
  71                                                                               \
  72       put32u (outbuf, BOM);                                                   \
  73       outbuf += 4;                                                            \
  74     }                                                                         \
  75   else if (__builtin_expect (data->__invocation_counter == 0, 0)              \
  76            && ((var == UTF_32LE && BYTE_ORDER == BIG_ENDIAN)                  \
  77                || (var == UTF_32BE && BYTE_ORDER == LITTLE_ENDIAN)))          \
  78     data->__flags |= __GCONV_SWAP;                                            \
  79   swap = data->__flags & __GCONV_SWAP;
  80 #define EXTRA_LOOP_ARGS         , var, swap
  81
  82
  83 /* Direction of the transformation.  */
  84 enum direction
  85 {
  86   illegal_dir,
  87   to_utf32,
  88   from_utf32
  89 };
  90
  91 enum variant
  92 {
  93   illegal_var,
  94   UTF_32,
  95   UTF_32LE,
  96   UTF_32BE
  97 };
  98
  99 struct utf32_data
 100 {
 101   enum direction dir;
 102   enum variant var;
 103 };
 104
 105
 106 extern int gconv_init (struct __gconv_step *step);
 107 int
 108 gconv_init (struct __gconv_step *step)
 109 {
 110   /* Determine which direction.  */
 111   struct utf32_data *new_data;
 112   enum direction dir = illegal_dir;
 113   enum variant var = illegal_var;
 114   int result;
 115
 116   if (__strcasecmp (step->__from_name, "UTF-32//") == 0)
 117     {
 118       dir = from_utf32;
 119       var = UTF_32;
 120     }
 121   else if (__strcasecmp (step->__to_name, "UTF-32//") == 0)
 122     {
 123       dir = to_utf32;
 124       var = UTF_32;
 125     }
 126   else if (__strcasecmp (step->__from_name, "UTF-32BE//") == 0)
 127     {
 128       dir = from_utf32;
 129       var = UTF_32BE;
 130     }
 131   else if (__strcasecmp (step->__to_name, "UTF-32BE//") == 0)
 132     {
 133       dir = to_utf32;
 134       var = UTF_32BE;
 135     }
 136   else if (__strcasecmp (step->__from_name, "UTF-32LE//") == 0)
 137     {
 138       dir = from_utf32;
 139       var = UTF_32LE;
 140     }
 141   else if (__strcasecmp (step->__to_name, "UTF-32LE//") == 0)
 142     {
 143       dir = to_utf32;
 144       var = UTF_32LE;
 145     }
 146
 147   result = __GCONV_NOCONV;
 148   if (__builtin_expect (dir, to_utf32) != illegal_dir)
 149     {
 150       new_data = (struct utf32_data *) malloc (sizeof (struct utf32_data));
 151
 152       result = __GCONV_NOMEM;
 153       if (new_data != NULL)
 154         {
 155           new_data->dir = dir;
 156           new_data->var = var;
 157           step->__data = new_data;
 158
 159           if (dir == from_utf32)
 160             {
 161               step->__min_needed_from = MIN_NEEDED_FROM;
 162               step->__max_needed_from = MIN_NEEDED_FROM;
 163               step->__min_needed_to = MIN_NEEDED_TO;
 164               step->__max_needed_to = MIN_NEEDED_TO;
 165             }
 166           else
 167             {
 168               step->__min_needed_from = MIN_NEEDED_TO;
 169               step->__max_needed_from = MIN_NEEDED_TO;
 170               step->__min_needed_to = MIN_NEEDED_FROM;
 171               step->__max_needed_to = MIN_NEEDED_FROM;
 172             }
 173
 174           step->__stateful = 0;
 175
 176           result = __GCONV_OK;
 177         }
 178     }
 179
 180   return result;
 181 }
 182
 183
 184 extern void gconv_end (struct __gconv_step *data);
 185 void
 186 gconv_end (struct __gconv_step *data)
 187 {
 188   free (data->__data);
 189 }
 190
 191
 192 /* Convert from the internal (UCS4-like) format to UTF-32.  */
 193 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
 194 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
 195 #define LOOPFCT                 TO_LOOP
 196 #define BODY \
 197   {                                                                           \
 198     uint32_t c = get32 (inptr);                                               \
 199                                                                               \
 200     if (__glibc_unlikely (c >= 0x110000))                                     \
 201       {                                                                       \
 202         STANDARD_TO_LOOP_ERR_HANDLER (4);                                     \
 203       }                                                                       \
 204     else if (__glibc_unlikely (c >= 0xd800 && c < 0xe000))                    \
 205       {                                                                       \
 206         /* Surrogate characters in UCS-4 input are not valid.                 \
 207            We must catch this.  If we let surrogates pass through,            \
 208            attackers could make a security hole exploit by                    \
 209            generating "irregular UTF-32" sequences.  */                       \
 210         result = __GCONV_ILLEGAL_INPUT;                                       \
 211         if (! ignore_errors_p ())                                             \
 212           break;                                                              \
 213         inptr += 4;                                                           \
 214         ++*irreversible;                                                      \
 215         continue;                                                             \
 216       }                                                                       \
 217                                                                               \
 218     if (swap)                                                                 \
 219       c = bswap_32 (c);                                                       \
 220     put32 (outptr, c);                                                        \
 221                                                                               \
 222     outptr += 4;                                                              \
 223     inptr += 4;                                                               \
 224   }
 225 #define LOOP_NEED_FLAGS
 226 #define EXTRA_LOOP_DECLS \
 227         , enum variant var, int swap
 228 #include <iconv/loop.c>
 229
 230
 231 /* Convert from UTF-32 to the internal (UCS4-like) format.  */
 232 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
 233 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
 234 #define LOOPFCT                 FROM_LOOP
 235 #define BODY \
 236   {                                                                           \
 237     uint32_t u1 = get32 (inptr);                                              \
 238                                                                               \
 239     if (swap)                                                                 \
 240       u1 = bswap_32 (u1);                                                     \
 241                                                                               \
 242     if (__glibc_unlikely (u1 >= 0x110000 || (u1 >= 0xd800 && u1 < 0xe000)))   \
 243       {                                                                       \
 244         /* This is illegal.  */                                               \
 245         STANDARD_FROM_LOOP_ERR_HANDLER (4);                                   \
 246       }                                                                       \
 247                                                                               \
 248     put32 (outptr, u1);                                                       \
 249     inptr += 4;                                                               \
 250     outptr += 4;                                                              \
 251   }
 252 #define LOOP_NEED_FLAGS
 253 #define EXTRA_LOOP_DECLS \
 254         , enum variant var, int swap
 255 #include <iconv/loop.c>
 256
 257
 258 /* Now define the toplevel functions.  */
 259 #include <iconv/skeleton.c>