iconvdata/unicode.c

   1 /* Conversion module for Unicode
   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     0xfeff
  29 /* And in the other endian format.  */
  30 #define BOM_OE  0xfffe
  31
  32
  33 /* Definitions used in the body of the `gconv' function.  */
  34 #define FROM_LOOP               from_unicode_loop
  35 #define TO_LOOP                 to_unicode_loop
  36 #define DEFINE_INIT             0
  37 #define DEFINE_FINI             0
  38 #define MIN_NEEDED_FROM         2
  39 #define MIN_NEEDED_TO           4
  40 #define ONE_DIRECTION           0
  41 #define FROM_DIRECTION          (dir == from_unicode)
  42 #define PREPARE_LOOP \
  43   enum direction dir = ((struct unicode_data *) step->__data)->dir;           \
  44   int swap;                                                                   \
  45   if (FROM_DIRECTION)                                                         \
  46     {                                                                         \
  47       if (data->__invocation_counter == 0)                                    \
  48         {                                                                     \
  49           /* We have to find out which byte order the file is encoded in.  */ \
  50           if (inptr + 2 > inend)                                              \
  51             return (inptr == inend                                            \
  52                     ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);        \
  53                                                                               \
  54           if (get16u (inptr) == BOM)                                          \
  55             /* Simply ignore the BOM character.  */                           \
  56             *inptrp = inptr += 2;                                             \
  57           else if (get16u (inptr) == BOM_OE)                                  \
  58             {                                                                 \
  59               data->__flags |= __GCONV_SWAP;                                  \
  60               *inptrp = inptr += 2;                                           \
  61             }                                                                 \
  62         }                                                                     \
  63     }                                                                         \
  64   else if (!data->__internal_use && data->__invocation_counter == 0)          \
  65     {                                                                         \
  66       /* Emit the Byte Order Mark.  */                                        \
  67       if (__glibc_unlikely (outbuf + 2 > outend))                             \
  68         return __GCONV_FULL_OUTPUT;                                           \
  69                                                                               \
  70       put16u (outbuf, BOM);                                                   \
  71       outbuf += 2;                                                            \
  72     }                                                                         \
  73   swap = data->__flags & __GCONV_SWAP;
  74 #define EXTRA_LOOP_ARGS         , swap
  75
  76
  77 /* Direction of the transformation.  */
  78 enum direction
  79 {
  80   illegal_dir,
  81   to_unicode,
  82   from_unicode
  83 };
  84
  85 struct unicode_data
  86 {
  87   enum direction dir;
  88 };
  89
  90
  91 extern int gconv_init (struct __gconv_step *step);
  92 int
  93 gconv_init (struct __gconv_step *step)
  94 {
  95   /* Determine which direction.  */
  96   struct unicode_data *new_data;
  97   enum direction dir = illegal_dir;
  98   int result;
  99
 100   if (strcmp (step->__from_name, "UNICODE//") == 0)
 101     dir = from_unicode;
 102   else
 103     dir = to_unicode;
 104
 105   new_data = (struct unicode_data *) malloc (sizeof (struct unicode_data));
 106
 107   result = __GCONV_NOMEM;
 108   if (new_data != NULL)
 109     {
 110       new_data->dir = dir;
 111       step->__data = new_data;
 112
 113       if (dir == from_unicode)
 114         {
 115           step->__min_needed_from = MIN_NEEDED_FROM;
 116           step->__max_needed_from = MIN_NEEDED_FROM;
 117           step->__min_needed_to = MIN_NEEDED_TO;
 118           step->__max_needed_to = MIN_NEEDED_TO;
 119         }
 120       else
 121         {
 122           step->__min_needed_from = MIN_NEEDED_TO;
 123           step->__max_needed_from = MIN_NEEDED_TO;
 124           step->__min_needed_to = MIN_NEEDED_FROM;
 125           step->__max_needed_to = MIN_NEEDED_FROM;
 126         }
 127
 128       step->__stateful = 0;
 129
 130       result = __GCONV_OK;
 131     }
 132
 133   return result;
 134 }
 135
 136
 137 extern void gconv_end (struct __gconv_step *data);
 138 void
 139 gconv_end (struct __gconv_step *data)
 140 {
 141   free (data->__data);
 142 }
 143
 144
 145 /* Convert from the internal (UCS4-like) format to UCS2.  */
 146 #define MIN_NEEDED_INPUT        MIN_NEEDED_TO
 147 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_FROM
 148 #define LOOPFCT                 TO_LOOP
 149 #define BODY \
 150   {                                                                           \
 151     uint32_t c = get32 (inptr);                                               \
 152                                                                               \
 153     if (__glibc_unlikely (c >= 0x10000))                                      \
 154       {                                                                       \
 155         UNICODE_TAG_HANDLER (c, 4);                                           \
 156         STANDARD_TO_LOOP_ERR_HANDLER (4);                                     \
 157       }                                                                       \
 158     else if (__glibc_unlikely (c >= 0xd800 && c < 0xe000))                    \
 159       {                                                                       \
 160         /* Surrogate characters in UCS-4 input are not valid.                 \
 161            We must catch this, because the UCS-2 output might be              \
 162            interpreted as UTF-16 by other programs.  If we let                \
 163            surrogates pass through, attackers could make a security           \
 164            hole exploit by synthesizing any desired plane 1-16                \
 165            character.  */                                                     \
 166         result = __GCONV_ILLEGAL_INPUT;                                       \
 167         if (! ignore_errors_p ())                                             \
 168           break;                                                              \
 169         inptr += 4;                                                           \
 170         ++*irreversible;                                                      \
 171         continue;                                                             \
 172       }                                                                       \
 173     else                                                                      \
 174       {                                                                       \
 175         put16 (outptr, c);                                                    \
 176         outptr += 2;                                                          \
 177       }                                                                       \
 178                                                                               \
 179     inptr += 4;                                                               \
 180   }
 181 #define LOOP_NEED_FLAGS
 182 #define EXTRA_LOOP_DECLS \
 183         , int swap
 184 #include <iconv/loop.c>
 185
 186
 187 /* Convert from UCS2 to the internal (UCS4-like) format.  */
 188 #define MIN_NEEDED_INPUT        MIN_NEEDED_FROM
 189 #define MIN_NEEDED_OUTPUT       MIN_NEEDED_TO
 190 #define LOOPFCT                 FROM_LOOP
 191 #define BODY \
 192   {                                                                           \
 193     uint16_t u1 = get16 (inptr);                                              \
 194                                                                               \
 195     if (swap)                                                                 \
 196       u1 = bswap_16 (u1);                                                     \
 197                                                                               \
 198     if (__glibc_unlikely (u1 >= 0xd800 && u1 < 0xe000))                       \
 199       {                                                                       \
 200         /* Surrogate characters in UCS-2 input are not valid.  Reject         \
 201            them.  (Catching this here is not security relevant.)  */          \
 202         STANDARD_FROM_LOOP_ERR_HANDLER (2);                                   \
 203       }                                                                       \
 204                                                                               \
 205     put32 (outptr, u1);                                                       \
 206                                                                               \
 207     inptr += 2;                                                               \
 208     outptr += 4;                                                              \
 209   }
 210 #define LOOP_NEED_FLAGS
 211 #define EXTRA_LOOP_DECLS \
 212         , int swap
 213 #include <iconv/loop.c>
 214
 215
 216 /* Now define the toplevel functions.  */
 217 #include <iconv/skeleton.c>