locale/loadlocale.c

   1 /* Functions to read locale data files.
   2 Copyright (C) 1995 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 Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 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 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <unistd.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <stdio.h>
  26 #include <sys/stat.h>
  27 #include <sys/mman.h>
  28 #include "localeinfo.h"
  29
  30 const size_t _nl_category_num_items[] =
  31   {
  32 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  33     [category] = _NL_ITEM_INDEX (_NL_NUM_##category),
  34 #include "categories.def"
  35 #undef  DEFINE_CATEGORY
  36   };
  37
  38 struct locale_data *
  39 _nl_load_locale (int category, char **name)
  40 {
  41   char *file;
  42   int fd;
  43   struct
  44     {
  45       unsigned int magic;
  46       unsigned int nstrings;
  47       unsigned int strindex[0];
  48     } *filedata;
  49   struct stat st;
  50   struct locale_data *newdata;
  51   int swap = 0;
  52   inline unsigned int SWAP (const unsigned int *inw)
  53     {
  54       const unsigned char *inc = (const unsigned char *) inw;
  55       if (!swap)
  56         return *inw;
  57       return (inc[3] << 24) | (inc[2] << 16) | (inc[1] << 8) | inc[0];
  58     }
  59   unsigned int i;
  60
  61   if ((*name)[0] == '\0')
  62     {
  63       *name = getenv ("LC_ALL");
  64       if (! *name || (*name)[0] == '\0')
  65         *name = getenv (_nl_category_names[category]);
  66       if (! *name || (*name)[0] == '\0')
  67         *name = getenv ("LANG");
  68       if (! *name || (*name)[0] == '\0')
  69         *name = (char *) "local";
  70     }
  71
  72 /* XXX can't use asprintf here */
  73   if (asprintf (&file, "%s%s/%s",
  74                 strchr (*name, '/') != NULL ? "" : "/share/locale/", /* XXX */
  75                 *name, _nl_category_names[category]) == -1)
  76     return NULL;
  77
  78   fd = __open (file, O_RDONLY);
  79   free (file);
  80   if (fd < 0)
  81     return NULL;
  82   if (__fstat (fd, &st) < 0)
  83     goto puntfd;
  84
  85   {
  86     /* Map in the file's data.  */
  87     int save = errno;
  88 #ifndef MAP_COPY
  89     /* Linux seems to lack read-only copy-on-write.  */
  90 #define MAP_COPY MAP_PRIVATE
  91 #endif
  92     filedata = (void *) __mmap ((caddr_t) 0, st.st_size,
  93                                 PROT_READ, MAP_FILE|MAP_COPY, fd, 0);
  94     if (filedata == (void *) -1)
  95       {
  96         if (errno == ENOSYS)
  97           {
  98             /* No mmap; allocate a buffer and read from the file.  */
  99             filedata = malloc (st.st_size);
 100             if (filedata)
 101               {
 102                 off_t to_read = st.st_size;
 103                 ssize_t nread;
 104                 char *p = (char *) filedata;
 105                 while (to_read > 0)
 106                   {
 107                     nread = __read (fd, p, to_read);
 108                     if (nread <= 0)
 109                       {
 110                         free (filedata);
 111                         if (nread == 0)
 112                           errno = EINVAL; /* Bizarreness going on.  */
 113                         goto puntfd;
 114                       }
 115                     p += nread;
 116                     to_read -= nread;
 117                   }
 118               }
 119             else
 120               goto puntfd;
 121             errno = save;
 122           }
 123         else
 124           goto puntfd;
 125       }
 126   }
 127
 128   if (filedata->magic == LIMAGIC (category))
 129     /* Good data file in our byte order.  */
 130     swap = 0;
 131   else
 132     {
 133       /* Try the other byte order.  */
 134       swap = 1;
 135       if (SWAP (&filedata->magic) != LIMAGIC (category))
 136         /* Bad data file in either byte order.  */
 137         {
 138         puntmap:
 139           __munmap ((caddr_t) filedata, st.st_size);
 140         puntfd:
 141           __close (fd);
 142           return NULL;
 143         }
 144     }
 145
 146 #define W(word) SWAP (&(word))
 147
 148   if (W (filedata->nstrings) < _nl_category_num_items[category] ||
 149       (sizeof *filedata + W (filedata->nstrings) * sizeof (unsigned int)
 150        >= st.st_size))
 151     {
 152       /* Insufficient data.  */
 153       errno = EINVAL;
 154       goto puntmap;
 155     }
 156
 157   newdata = malloc (sizeof *newdata +
 158                     W (filedata->nstrings) * sizeof (char *));
 159   if (! newdata)
 160     goto puntmap;
 161
 162   newdata->filedata = (void *) filedata;
 163   newdata->filesize = st.st_size;
 164   newdata->nstrings = W (filedata->nstrings);
 165   for (i = 0; i < newdata->nstrings; ++i)
 166     {
 167       unsigned int idx = W (filedata->strindex[i]);
 168       if (idx >= newdata->filesize)
 169         {
 170           free (newdata);
 171           errno = EINVAL;
 172           goto puntmap;
 173         }
 174       newdata->strings[i] = newdata->filedata + idx;
 175     }
 176
 177   __close (fd);
 178   return newdata;
 179 }
 180 \f
 181 void
 182 _nl_free_locale (struct locale_data *data)
 183 {
 184   int save = errno;
 185   if (__munmap ((caddr_t) data->filedata, data->filesize) < 0)
 186     {
 187       if (errno == ENOSYS)
 188         free ((void *) data->filedata);
 189       errno = save;
 190     }
 191   free (data);
 192 }
 193