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   int fd;
  42   struct
  43     {
  44       unsigned int magic;
  45       unsigned int nstrings;
  46       unsigned int strindex[0];
  47     } *filedata;
  48   struct stat st;
  49   struct locale_data *newdata;
  50   int swap = 0;
  51   inline unsigned int SWAP (const unsigned int *inw)
  52     {
  53       const unsigned char *inc = (const unsigned char *) inw;
  54       if (!swap)
  55         return *inw;
  56       return (inc[3] << 24) | (inc[2] << 16) | (inc[1] << 8) | inc[0];
  57     }
  58   unsigned int i;
  59
  60   if ((*name)[0] == '\0')
  61     {
  62       *name = getenv ("LC_ALL");
  63       if (! *name || (*name)[0] == '\0')
  64         *name = getenv (_nl_category_names[category]);
  65       if (! *name || (*name)[0] == '\0')
  66         *name = getenv ("LANG");
  67       if (! *name || (*name)[0] == '\0')
  68         *name = (char *) "local";
  69     }
  70
  71   {
  72     const char *catname = _nl_category_names[category];
  73     size_t namelen = strlen (*name);
  74     size_t catlen = strlen (catname);
  75     char file[sizeof LOCALE_PATH + 1 + namelen + catlen * 2 + 4];
  76     if (strchr (*name, '/') != NULL)
  77       sprintf (file, "%s/%s", *name, catname);
  78     else
  79       sprintf (file, "%s/%s/%s", LOCALE_PATH, *name, catname);
  80     fd = __open (file, O_RDONLY);
  81     if (fd < 0)
  82       return NULL;
  83     if (__fstat (fd, &st) < 0)
  84       goto puntfd;
  85     if (S_ISDIR (st.st_mode))
  86       {
  87         /* LOCALE/LC_foo is a directory; open LOCALE/LC_foo/SYS_LC_foo
  88            instead.  */
  89         __close (fd);
  90         memcpy (stpcpy (strchr (file, '\0'), "SYS_"), catname, catlen);
  91         fd = __open (file, O_RDONLY);
  92         if (fd < 0)
  93           return NULL;
  94         if (__fstat (fd, &st) < 0)
  95           goto puntfd;
  96       }
  97   }
  98
  99   {
 100     /* Map in the file's data.  */
 101     int save = errno;
 102 #ifndef MAP_COPY
 103     /* Linux seems to lack read-only copy-on-write.  */
 104 #define MAP_COPY MAP_PRIVATE
 105 #endif
 106 #ifndef MAP_FILE
 107     /* Some systems do not have this flag; it is superfluous.  */
 108 #define MAP_FILE 0
 109 #endif
 110 #ifndef MAP_INHERIT
 111     /* Some systems might lack this; they lose.  */
 112 #define MAP_INHERIT 0
 113 #endif
 114     filedata = (void *) __mmap ((caddr_t) 0, st.st_size,
 115                                 PROT_READ, MAP_FILE|MAP_COPY|MAP_INHERIT,
 116                                 fd, 0);
 117     if (filedata == (void *) -1)
 118       {
 119         if (errno == ENOSYS)
 120           {
 121             /* No mmap; allocate a buffer and read from the file.  */
 122             filedata = malloc (st.st_size);
 123             if (filedata)
 124               {
 125                 off_t to_read = st.st_size;
 126                 ssize_t nread;
 127                 char *p = (char *) filedata;
 128                 while (to_read > 0)
 129                   {
 130                     nread = __read (fd, p, to_read);
 131                     if (nread <= 0)
 132                       {
 133                         free (filedata);
 134                         if (nread == 0)
 135                           errno = EINVAL; /* Bizarreness going on.  */
 136                         goto puntfd;
 137                       }
 138                     p += nread;
 139                     to_read -= nread;
 140                   }
 141               }
 142             else
 143               goto puntfd;
 144             errno = save;
 145           }
 146         else
 147           goto puntfd;
 148       }
 149   }
 150
 151   if (filedata->magic == LIMAGIC (category))
 152     /* Good data file in our byte order.  */
 153     swap = 0;
 154   else
 155     {
 156       /* Try the other byte order.  */
 157       swap = 1;
 158       if (SWAP (&filedata->magic) != LIMAGIC (category))
 159         /* Bad data file in either byte order.  */
 160         {
 161         puntmap:
 162           __munmap ((caddr_t) filedata, st.st_size);
 163         puntfd:
 164           __close (fd);
 165           return NULL;
 166         }
 167     }
 168
 169 #define W(word) SWAP (&(word))
 170
 171   if (W (filedata->nstrings) < _nl_category_num_items[category] ||
 172       (sizeof *filedata + W (filedata->nstrings) * sizeof (unsigned int)
 173        >= st.st_size))
 174     {
 175       /* Insufficient data.  */
 176       errno = EINVAL;
 177       goto puntmap;
 178     }
 179
 180   newdata = malloc (sizeof *newdata +
 181                     W (filedata->nstrings) * sizeof (char *));
 182   if (! newdata)
 183     goto puntmap;
 184
 185   newdata->filedata = (void *) filedata;
 186   newdata->filesize = st.st_size;
 187   newdata->nstrings = W (filedata->nstrings);
 188   for (i = 0; i < newdata->nstrings; ++i)
 189     {
 190       unsigned int idx = W (filedata->strindex[i]);
 191       if (idx >= newdata->filesize)
 192         {
 193           free (newdata);
 194           errno = EINVAL;
 195           goto puntmap;
 196         }
 197       newdata->strings[i] = newdata->filedata + idx;
 198     }
 199
 200   __close (fd);
 201   return newdata;
 202 }
 203 \f
 204 void
 205 _nl_free_locale (struct locale_data *data)
 206 {
 207   int save = errno;
 208   if (! data)
 209     /* Ignore a null pointer, like free does.  */
 210     return;
 211   if (__munmap ((caddr_t) data->filedata, data->filesize) < 0)
 212     {
 213       if (errno == ENOSYS)
 214         free ((void *) data->filedata);
 215       errno = save;
 216     }
 217   free (data);
 218 }
 219