iconvdata/utf-16.c

   1 /* Conversion module for UTF-16.
   2    Copyright (C) 1999-2022 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     0xfeff
  29 /* And in the other byte order.  */
  30 #define BOM_OE  0xfffe
  31
  32
  33 /* Definitions used in the body of the `gconv' function.  */
  34 #define FROM_LOOP               from_utf16_loop
  35 #define TO_LOOP                 to_utf16_loop
  36 #define DEFINE_INIT             0
  37 #define DEFINE_FINI             0
  38 #define MIN_NEEDED_FROM         2
  39 #define MAX_NEEDED_FROM         4
  40 #define MIN_NEEDED_TO           4
  41 #define ONE_DIRECTION           0
  42 #define FROM_DIRECTION          (dir == from_utf16)
  43 #define PREPARE_LOOP \
  44   enum direction dir = ((struct utf16_data *) step->__data)->dir;             \
  45   enum variant var = ((struct utf16_data *) step->__data)->var;               \
  46   if (__glibc_unlikely (data->__invocation_counter == 0))                     \
  47     {                                                                         \
  48       if (var == UTF_16)                                                      \
  49         {                                                                     \
  50           if (FROM_DIRECTION)                                                 \
  51             {                                                                 \
  52               /* We have to find out which byte order the file is             \
  53                  encoded in.  */                                              \
  54               if (inptr + 2 > inend)                                          \
  55                 return (inptr == inend                                        \
  56                         ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);    \
  57                                                                               \
  58               if (get16u (inptr) == BOM)                                      \
  59                 /* Simply ignore the BOM character.  */                       \
  60                 *inptrp = inptr += 2;                                         \
  61               else if (get16u (inptr) == BOM_OE)                              \
  62                 {                                                             \
  63                   data->__flags |= __GCONV_SWAP;                              \
  64                   *inptrp = inptr += 2;                                       \
  65                 }                                                             \
  66             }                                                                 \
  67           else if (!FROM_DIRECTION && !data->__internal_use)                  \
  68             {                                                                 \
  69               /* Emit the Byte Order Mark.  */                                \
  70               if (__glibc_unlikely (outbuf + 2 > outend))                     \
  71                 return __GCONV_FULL_OUTPUT;                                   \
  72                                                                               \
  73               put16u (outbuf, BOM);                                           \
  74               outbuf += 2;                                                    \
  75             }                                                                 \
  76         }                                                                     \
  77       else if ((var == UTF_16LE && BYTE_ORDER == BIG_ENDIAN)                  \
  78                || (var == UTF_16BE && BYTE_ORDER == LITTLE_ENDIAN))           \
  79         data->__flags |= __GCONV_SWAP;                                        \
  80     }                                                                         \
  81   const int swap = data->__flags & __GCONV_SWAP;
  82 #define EXTRA_LOOP_ARGS         , swap
  83
  84
  85 /* Direction of the transformation.  */
  86 enum direction
  87 {
  88   illegal_dir,
  89   to_utf16,
  90   from_utf16
  91 };
  92
  93 enum variant
  94 {
  95   illegal_var,
  96   UTF_16,
  97   UTF_16LE,
  98   UTF_16BE
  99 };
 100
 101 struct utf16_data
 102 {
 103   enum direction dir;
 104   enum variant var;
 105 };
 106
 107
 108 extern int gconv_init (struct __gconv_step *step);
 109 int
 110 gconv_init (struct __gconv_step *step)
 111 {
 112   /* Determine which direction.  */
 113   struct utf16_data *new_data;
 114   enum direction dir = illegal_dir;
 115   enum variant var = illegal_var;
 116   int result;
 117
 118   if (__strcasecmp (step->__from_name, "UTF-16//") == 0)
 119     {
 120       dir = from_utf16;
 121       var = UTF_16;
 122     }
 123   else if (__strcasecmp (step->__to_name, "UTF-16//") == 0)
 124     {
 125       dir = to_utf16;
 126       var = UTF_16;
 127     }
 128   else if (__strcasecmp (step->__from_name, "UTF-16BE//") == 0)
 129     {
 130       dir = from_utf16;
 131       var = UTF_16BE;
 132     }
 133   else if (__strcasecmp (step->__to_name, "UTF-16BE//") == 0)
 134     {
 135       dir = to_utf16;
 136       var = UTF_16BE;
 137     }
 138   else if (__strcasecmp (step->__from_name, "UTF-16LE//") == 0)
 139     {
 140       dir = from_utf16;
 141       var = UTF_16LE;
 142     }
 143   else if (__strcasecmp (step->__to_name, "UTF-16LE//") == 0)
 144     {
 145       dir = to_utf16;
 146       var = UTF_16LE;
 147     }
 148
 149   result = __GCONV_NOCONV;
 150   if (__builtin_expect (dir, to_utf16) != illegal_dir)
 151     {
 152       new_data = (struct utf16_data *) malloc (sizeof (struct utf16_data));
 153
 154       result = __GCONV_NOMEM;
 155       if (new_data != NULL)
 156         {
 157           new_data->dir = dir;
 158           new_data->var = var;
 159           step->__data = new_data;
 160
 161           if (dir == from_utf16)
 162             {
 163               step->__min_needed_from = MIN_NEEDED_FROM;
 164               step->__max_needed_from = MAX_NEEDED_FROM;
 165               step->__min_needed_to = MIN_NEEDED_TO;
 166               step->__max_needed_to = MIN_NEEDED_TO;
 167             }
 168           else
 169             {
 170               step->__min_needed_from = MIN_NEEDED_TO;
 171               step->__max_needed_from = MIN_NEEDED_TO;
 172               step->__min_needed_to = MIN_NEEDED_FROM;
 173               step->__max_needed_to = MAX_NEEDED_FROM;
 174             }
 175
 176           step->__stateful = 0;
 177
 178           result = __GCONV_OK;
 179         }
 180     }
 181
 182   return result;
 183 }
 184
 185
 186 extern void gconv_end (struct __gconv_step *data);
 187 void
 188 gconv_end (struct __gconv_step *data)
 189 {
 190   free (data->__data);
 191 }
 192
 193
 194 /* Convert from the internal (UCS4-like) format to UTF-16.  */
 195 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
 196 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
 197 #define MAX_NEEDED_OUTPUT       MAX_NEEDED_FROM
 198 #define LOOPFCT                 TO_LOOP
 199 #define BODY \
 200   {                                                                           \
 201     uint32_t c = get32 (inptr);                                               \
 202                                                                               \
 203     if (__glibc_unlikely (c >= 0xd800 && c < 0xe000))                         \
 204       {                                                                       \
 205         /* Surrogate characters in UCS-4 input are not valid.                 \
 206            We must catch this.  If we let surrogates pass through,            \
 207            attackers could make a security hole exploit by                    \
 208            synthesizing any desired plane 1-16 character.  */                 \
 209         result = __GCONV_ILLEGAL_INPUT;                                       \
 210         if (! ignore_errors_p ())                                             \
 211           break;                                                              \
 212         inptr += 4;                                                           \
 213         ++*irreversible;                                                      \
 214         continue;                                                             \
 215       }                                                                       \
 216                                                                               \
 217     if (swap)                                                                 \
 218       {                                                                       \
 219         if (__glibc_unlikely (c >= 0x10000))                                  \
 220           {                                                                   \
 221             if (__glibc_unlikely (c >= 0x110000))                             \
 222               {                                                               \
 223                 STANDARD_TO_LOOP_ERR_HANDLER (4);                             \
 224               }                                                               \
 225                                                                               \
 226             /* Generate a surrogate character.  */                            \
 227             if (__glibc_unlikely (outptr + 4 > outend))                       \
 228               {                                                               \
 229                 /* Overflow in the output buffer.  */                         \
 230                 result = __GCONV_FULL_OUTPUT;                                 \
 231                 break;                                                        \
 232               }                                                               \
 233                                                                               \
 234             put16 (outptr, bswap_16 (0xd7c0 + (c >> 10)));                    \
 235             outptr += 2;                                                      \
 236             put16 (outptr, bswap_16 (0xdc00 + (c & 0x3ff)));                  \
 237           }                                                                   \
 238         else                                                                  \
 239           put16 (outptr, bswap_16 (c));                                       \
 240       }                                                                       \
 241     else                                                                      \
 242       {                                                                       \
 243         if (__glibc_unlikely (c >= 0x10000))                                  \
 244           {                                                                   \
 245             if (__glibc_unlikely (c >= 0x110000))                             \
 246               {                                                               \
 247                 STANDARD_TO_LOOP_ERR_HANDLER (4);                             \
 248               }                                                               \
 249                                                                               \
 250             /* Generate a surrogate character.  */                            \
 251             if (__glibc_unlikely (outptr + 4 > outend))                       \
 252               {                                                               \
 253                 /* Overflow in the output buffer.  */                         \
 254                 result = __GCONV_FULL_OUTPUT;                                 \
 255                 break;                                                        \
 256               }                                                               \
 257                                                                               \
 258             put16 (outptr, 0xd7c0 + (c >> 10));                               \
 259             outptr += 2;                                                      \
 260             put16 (outptr, 0xdc00 + (c & 0x3ff));                             \
 261           }                                                                   \
 262         else                                                                  \
 263           put16 (outptr, c);                                                  \
 264       }                                                                       \
 265     outptr += 2;                                                              \
 266     inptr += 4;                                                               \
 267   }
 268 #define LOOP_NEED_FLAGS
 269 #define EXTRA_LOOP_DECLS \
 270         , int swap
 271 #include <iconv/loop.c>
 272
 273
 274 /* Convert from UTF-16 to the internal (UCS4-like) format.  */
 275 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
 276 #define MAX_NEEDED_INPUT        MAX_NEEDED_FROM
 277 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
 278 #define LOOPFCT                 FROM_LOOP
 279 #define BODY \
 280   {                                                                           \
 281     uint16_t u1 = get16 (inptr);                                              \
 282                                                                               \
 283     if (swap)                                                                 \
 284       {                                                                       \
 285         u1 = bswap_16 (u1);                                                   \
 286                                                                               \
 287         if (__builtin_expect (u1 < 0xd800, 1) || u1 > 0xdfff)                 \
 288           {                                                                   \
 289             /* No surrogate.  */                                              \
 290             put32 (outptr, u1);                                               \
 291             inptr += 2;                                                       \
 292           }                                                                   \
 293         else                                                                  \
 294           {                                                                   \
 295             uint16_t u2;                                                      \
 296                                                                               \
 297             if (__glibc_unlikely (u1 >= 0xdc00))                              \
 298               {                                                               \
 299                 /* This is no valid first word for a surrogate.  */           \
 300                 STANDARD_FROM_LOOP_ERR_HANDLER (2);                           \
 301               }                                                               \
 302                                                                               \
 303             /* It's a surrogate character.  At least the first word says      \
 304                it is.  */                                                     \
 305             if (__glibc_unlikely (inptr + 4 > inend))                         \
 306               {                                                               \
 307                 /* We don't have enough input for another complete input      \
 308                    character.  */                                             \
 309                 result = __GCONV_INCOMPLETE_INPUT;                            \
 310                 break;                                                        \
 311               }                                                               \
 312                                                                               \
 313             inptr += 2;                                                       \
 314             u2 = bswap_16 (get16 (inptr));                                    \
 315             if (__builtin_expect (u2 < 0xdc00, 0)                             \
 316                 || __builtin_expect (u2 > 0xdfff, 0))                         \
 317               {                                                               \
 318                 /* This is no valid second word for a surrogate.  */          \
 319                 inptr -= 2;                                                   \
 320                 STANDARD_FROM_LOOP_ERR_HANDLER (2);                           \
 321               }                                                               \
 322                                                                               \
 323             put32 (outptr, ((u1 - 0xd7c0) << 10) + (u2 - 0xdc00));            \
 324             inptr += 2;                                                       \
 325           }                                                                   \
 326       }                                                                       \
 327     else                                                                      \
 328       {                                                                       \
 329         if (__builtin_expect (u1 < 0xd800, 1) || u1 > 0xdfff)                 \
 330           {                                                                   \
 331             /* No surrogate.  */                                              \
 332             put32 (outptr, u1);                                               \
 333             inptr += 2;                                                       \
 334           }                                                                   \
 335         else                                                                  \
 336           {                                                                   \
 337             if (__glibc_unlikely (u1 >= 0xdc00))                              \
 338               {                                                               \
 339                 /* This is no valid first word for a surrogate.  */           \
 340                 STANDARD_FROM_LOOP_ERR_HANDLER (2);                           \
 341               }                                                               \
 342                                                                               \
 343             /* It's a surrogate character.  At least the first word says      \
 344                it is.  */                                                     \
 345             if (__glibc_unlikely (inptr + 4 > inend))                         \
 346               {                                                               \
 347                 /* We don't have enough input for another complete input      \
 348                    character.  */                                             \
 349                 result = __GCONV_INCOMPLETE_INPUT;                            \
 350                 break;                                                        \
 351               }                                                               \
 352                                                                               \
 353             inptr += 2;                                                       \
 354             uint16_t u2 = get16 (inptr);                                      \
 355             if (__builtin_expect (u2 < 0xdc00, 0)                             \
 356                 || __builtin_expect (u2 > 0xdfff, 0))                         \
 357               {                                                               \
 358                 /* This is no valid second word for a surrogate.  */          \
 359                 inptr -= 2;                                                   \
 360                 STANDARD_FROM_LOOP_ERR_HANDLER (2);                           \
 361               }                                                               \
 362                                                                               \
 363             put32 (outptr, ((u1 - 0xd7c0) << 10) + (u2 - 0xdc00));            \
 364             inptr += 2;                                                       \
 365           }                                                                   \
 366       }                                                                       \
 367     outptr += 4;                                                              \
 368   }
 369 #define LOOP_NEED_FLAGS
 370 #define EXTRA_LOOP_DECLS \
 371         , int swap
 372 #include <iconv/loop.c>
 373
 374
 375 /* Now define the toplevel functions.  */
 376 #include <iconv/skeleton.c>