catgets/open_catalog.c

   1 /* Copyright (C) 1996 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3 Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>.
   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., 59 Temple Place - Suite 330,
  18 Boston, MA 02111-1307, USA.  */
  19
  20 #include <endian.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <sys/mman.h>
  26 #include <sys/stat.h>
  27
  28 #include "catgetsinfo.h"
  29
  30
  31 #define SWAPU32(w) \
  32   (((w) << 24) | (((w) & 0xff00) << 8) | (((w) >> 8) & 0xff00) | ((w) >> 24))
  33
  34
  35 void
  36 __open_catalog (__nl_catd catalog, int with_path)
  37 {
  38   int fd;
  39   struct stat st;
  40   int swapping;
  41
  42   if (strchr (catalog->cat_name, '/') != NULL || !with_path)
  43     fd = open (catalog->cat_name, O_RDONLY);
  44   else
  45     {
  46       const char *run_nlspath = catalog->nlspath;
  47 #define ENOUGH(n)                                                             \
  48   if (bufact + (n) >=bufmax)                                                  \
  49     {                                                                         \
  50       char *old_buf = buf;                                                    \
  51       bufmax += 256 + (n);                                                    \
  52       buf = (char *) alloca (bufmax);                                         \
  53       memcpy (buf, old_buf, bufact);                                          \
  54     }
  55
  56       /* The RUN_NLSPATH variable contains a colon separated list of
  57          descriptions where we expect to find catalogs.  We have to
  58          recognize certain % substitutions and stop when we found the
  59          first existing file.  */
  60       char *buf;
  61       size_t bufact;
  62       size_t bufmax;
  63
  64       buf = NULL;
  65       bufmax = 0;
  66
  67       fd = -1;
  68       while (*run_nlspath != '\0')
  69         {
  70           bufact = 0;
  71           while (*run_nlspath != ':' && *run_nlspath != '\0')
  72             if (*run_nlspath == '%')
  73               {
  74                 const char *tmp;
  75
  76                 ++run_nlspath;  /* We have seen the `%'.  */
  77                 switch (*run_nlspath++)
  78                   {
  79                   case 'N':
  80                     /* Use the catalog name.  */
  81                     ENOUGH (strlen (catalog->cat_name));
  82                     bufact = stpcpy (&buf[bufact], catalog->cat_name) - buf;
  83                     break;
  84                   case 'L':
  85                     /* Use the current locale category value.  */
  86                     ENOUGH (strlen (catalog->env_var));
  87                     bufact = stpcpy (&buf[bufact], catalog->env_var) - buf;
  88                     break;
  89                   case 'l':
  90                     /* Use language element of locale category value.  */
  91                     tmp = catalog->env_var;
  92                     do
  93                       {
  94                         ENOUGH (1);
  95                         buf[bufact++] = *tmp++;
  96                       }
  97                     while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
  98                     break;
  99                   case 't':
 100                     /* Use territory element of locale category value.  */
 101                     tmp = catalog->env_var;
 102                     do
 103                       ++tmp;
 104                     while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
 105                     if (*tmp == '_')
 106                       {
 107                         ++tmp;
 108                         do
 109                           {
 110                             ENOUGH (1);
 111                             buf[bufact++] = *tmp;
 112                           }
 113                         while (*tmp != '\0' && *tmp != '.');
 114                       }
 115                     break;
 116                   case 'c':
 117                     /* Use code set element of locale category value.  */
 118                     tmp = catalog->env_var;
 119                     do
 120                       ++tmp;
 121                     while (*tmp != '\0' && *tmp != '.');
 122                     if (*tmp == '.')
 123                       {
 124                         ++tmp;
 125                         do
 126                           {
 127                             ENOUGH (1);
 128                             buf[bufact++] = *tmp;
 129                           }
 130                         while (*tmp != '\0');
 131                       }
 132                     break;
 133                   case '%':
 134                     ENOUGH (1);
 135                     buf[bufact++] = '%';
 136                     break;
 137                   default:
 138                     /* Unknown variable: ignore this path element.  */
 139                     bufact = 0;
 140                     while (*run_nlspath != '\0' && *run_nlspath != ':')
 141                       ++run_nlspath;
 142                     break;
 143                   }
 144               }
 145             else
 146               {
 147                 ENOUGH (1);
 148                 buf[bufact++] = *run_nlspath++;
 149               }
 150           ENOUGH (1);
 151           buf[bufact] = '\0';
 152
 153           if (bufact != 0)
 154             {
 155               fd = open (buf, O_RDONLY);
 156               if (fd >= 0)
 157                 break;
 158             }
 159
 160           ++run_nlspath;
 161         }
 162     }
 163
 164   if (fd < 0 || fstat (fd, &st) < 0)
 165     {
 166       catalog->status = nonexisting;
 167       return;
 168     }
 169
 170 #ifndef MAP_COPY
 171     /* Linux seems to lack read-only copy-on-write.  */
 172 #define MAP_COPY MAP_PRIVATE
 173 #endif
 174 #ifndef MAP_FILE
 175     /* Some systems do not have this flag; it is superfluous.  */
 176 #define MAP_FILE 0
 177 #endif
 178 #ifndef MAP_INHERIT
 179     /* Some systems might lack this; they lose.  */
 180 #define MAP_INHERIT 0
 181 #endif
 182   catalog->file_size = st.st_size;
 183   catalog->file_ptr =
 184     (struct catalog_obj *) mmap (NULL, st.st_size, PROT_READ,
 185                                  MAP_FILE|MAP_COPY|MAP_INHERIT, fd, 0);
 186   if (catalog->file_ptr != (struct catalog_obj *) -1)
 187     /* Tell the world we managed to mmap the file.  */
 188     catalog->status = mmaped;
 189   else
 190     {
 191       /* mmap failed perhaps because the system call is not
 192          implemented.  Try to load the file.  */
 193       size_t todo;
 194       catalog->file_ptr = malloc (st.st_size);
 195       if (catalog->file_ptr == NULL)
 196         {
 197           catalog->status = nonexisting;
 198           return;
 199         }
 200       todo = st.st_size;
 201       /* Save read, handle partial reads.  */
 202       do
 203         {
 204           size_t now = read (fd, (((char *) &catalog->file_ptr)
 205                                   + (st.st_size - todo)), todo);
 206           if (now == 0)
 207             {
 208               free ((void *) catalog->file_ptr);
 209               catalog->status = nonexisting;
 210               return;
 211             }
 212           todo -= now;
 213         }
 214       while (todo > 0);
 215       catalog->status = malloced;
 216     }
 217
 218   /* We don't need the file anymore.  */
 219   close (fd);
 220
 221   /* Determine whether the file is a catalog file and if yes whether
 222      it is written using the correct byte order.  Else we have to swap
 223      the values.  */
 224   if (catalog->file_ptr->magic == CATGETS_MAGIC)
 225     swapping = 0;
 226   else if (catalog->file_ptr->magic == SWAPU32 (CATGETS_MAGIC))
 227     swapping = 1;
 228   else
 229     {
 230       /* Illegal file.  Free he resources and mark catalog as not
 231          usable.  */
 232       if (catalog->status == mmaped)
 233         munmap ((void *) catalog->file_ptr, catalog->file_size);
 234       else
 235         free (catalog->file_ptr);
 236       catalog->status = nonexisting;
 237       return;
 238     }
 239
 240 #define SWAP(x) (swapping ? SWAPU32 (x) : (x))
 241
 242   /* Get dimensions of the used hashing table.  */
 243   catalog->plane_size = SWAP (catalog->file_ptr->plane_size);
 244   catalog->plane_depth = SWAP (catalog->file_ptr->plane_depth);
 245
 246   /* The file contains two versions of the pointer tables.  Pick the
 247      right one for the local byte order.  */
 248 #if __BYTE_ORDER == __LITTLE_ENDIAN
 249   catalog->name_ptr = &catalog->file_ptr->name_ptr[0];
 250 #elif __BYTE_ORDER == __BIG_ENDIAN
 251   catalog->name_ptr = &catalog->file_ptr->name_ptr[catalog->plane_size
 252                                                   * catalog->plane_depth
 253                                                   * 3];
 254 #else
 255 # error Cannot handle __BYTE_ORDER byte order
 256 #endif
 257
 258   /* The rest of the file contains all the strings.  They are
 259      addressed relative to the position of the first string.  */
 260   catalog->strings =
 261     (const char *) &catalog->file_ptr->name_ptr[catalog->plane_size
 262                                                * catalog->plane_depth * 3 * 2];
 263 }