catgets/open_catalog.c

   1 /* Copyright (C) 1996, 1997, 1998 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 not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <byteswap.h>
  21 #include <endian.h>
  22 #include <fcntl.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <sys/mman.h>
  27 #include <sys/stat.h>
  28
  29 #include "catgetsinfo.h"
  30
  31
  32 #define SWAPU32(w) bswap_32 (w)
  33
  34
  35 void
  36 __open_catalog (__nl_catd catalog)
  37 {
  38   int fd = -1;
  39   struct stat st;
  40   int swapping;
  41
  42   /* Make sure we are alone.  */
  43   __libc_lock_lock (catalog->lock);
  44
  45   /* Check whether there was no other thread faster.  */
  46   if (catalog->status != closed)
  47     /* While we waited some other thread tried to open the catalog.  */
  48     goto unlock_return;
  49
  50   if (strchr (catalog->cat_name, '/') != NULL || catalog->nlspath == NULL)
  51     fd = __open (catalog->cat_name, O_RDONLY);
  52   else
  53     {
  54       const char *run_nlspath = catalog->nlspath;
  55 #define ENOUGH(n)                                                             \
  56   if (bufact + (n) >=bufmax)                                                  \
  57     {                                                                         \
  58       char *old_buf = buf;                                                    \
  59       bufmax += 256 + (n);                                                    \
  60       buf = (char *) alloca (bufmax);                                         \
  61       memcpy (buf, old_buf, bufact);                                          \
  62     }
  63
  64       /* The RUN_NLSPATH variable contains a colon separated list of
  65          descriptions where we expect to find catalogs.  We have to
  66          recognize certain % substitutions and stop when we found the
  67          first existing file.  */
  68       char *buf;
  69       size_t bufact;
  70       size_t bufmax;
  71       size_t len;
  72
  73       buf = NULL;
  74       bufmax = 0;
  75
  76       fd = -1;
  77       while (*run_nlspath != '\0')
  78         {
  79           bufact = 0;
  80           while (*run_nlspath != ':' && *run_nlspath != '\0')
  81             if (*run_nlspath == '%')
  82               {
  83                 const char *tmp;
  84
  85                 ++run_nlspath;  /* We have seen the `%'.  */
  86                 switch (*run_nlspath++)
  87                   {
  88                   case 'N':
  89                     /* Use the catalog name.  */
  90                     len = strlen (catalog->cat_name);
  91                     ENOUGH (len);
  92                     memcpy (&buf[bufact], catalog->cat_name, len);
  93                     bufact += len;
  94                     break;
  95                   case 'L':
  96                     /* Use the current locale category value.  */
  97                     len = strlen (catalog->env_var);
  98                     ENOUGH (len);
  99                     memcpy (&buf[bufact], catalog->env_var, len);
 100                     bufact += len;
 101                     break;
 102                   case 'l':
 103                     /* Use language element of locale category value.  */
 104                     tmp = catalog->env_var;
 105                     do
 106                       {
 107                         ENOUGH (1);
 108                         buf[bufact++] = *tmp++;
 109                       }
 110                     while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
 111                     break;
 112                   case 't':
 113                     /* Use territory element of locale category value.  */
 114                     tmp = catalog->env_var;
 115                     do
 116                       ++tmp;
 117                     while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
 118                     if (*tmp == '_')
 119                       {
 120                         ++tmp;
 121                         do
 122                           {
 123                             ENOUGH (1);
 124                             buf[bufact++] = *tmp;
 125                           }
 126                         while (*tmp != '\0' && *tmp != '.');
 127                       }
 128                     break;
 129                   case 'c':
 130                     /* Use code set element of locale category value.  */
 131                     tmp = catalog->env_var;
 132                     do
 133                       ++tmp;
 134                     while (*tmp != '\0' && *tmp != '.');
 135                     if (*tmp == '.')
 136                       {
 137                         ++tmp;
 138                         do
 139                           {
 140                             ENOUGH (1);
 141                             buf[bufact++] = *tmp;
 142                           }
 143                         while (*tmp != '\0');
 144                       }
 145                     break;
 146                   case '%':
 147                     ENOUGH (1);
 148                     buf[bufact++] = '%';
 149                     break;
 150                   default:
 151                     /* Unknown variable: ignore this path element.  */
 152                     bufact = 0;
 153                     while (*run_nlspath != '\0' && *run_nlspath != ':')
 154                       ++run_nlspath;
 155                     break;
 156                   }
 157               }
 158             else
 159               {
 160                 ENOUGH (1);
 161                 buf[bufact++] = *run_nlspath++;
 162               }
 163           ENOUGH (1);
 164           buf[bufact] = '\0';
 165
 166           if (bufact != 0)
 167             {
 168               fd = __open (buf, O_RDONLY);
 169               if (fd >= 0)
 170                 break;
 171             }
 172
 173           ++run_nlspath;
 174         }
 175     }
 176
 177   /* Avoid dealing with directories and block devices */
 178   if (fd < 0 || __fstat (fd, &st) < 0 || !S_ISREG (st.st_mode))
 179     {
 180       catalog->status = nonexisting;
 181       goto unlock_return;
 182     }
 183
 184 #ifndef MAP_COPY
 185     /* Linux seems to lack read-only copy-on-write.  */
 186 # define MAP_COPY MAP_PRIVATE
 187 #endif
 188 #ifndef MAP_FILE
 189     /* Some systems do not have this flag; it is superfluous.  */
 190 # define MAP_FILE 0
 191 #endif
 192 #ifndef MAP_INHERIT
 193     /* Some systems might lack this; they lose.  */
 194 # define MAP_INHERIT 0
 195 #endif
 196   catalog->file_size = st.st_size;
 197   catalog->file_ptr =
 198     (struct catalog_obj *) __mmap (NULL, st.st_size, PROT_READ,
 199                                    MAP_FILE|MAP_COPY|MAP_INHERIT, fd, 0);
 200   if (catalog->file_ptr != (struct catalog_obj *) MAP_FAILED)
 201     /* Tell the world we managed to mmap the file.  */
 202     catalog->status = mmapped;
 203   else
 204     {
 205       /* mmap failed perhaps because the system call is not
 206          implemented.  Try to load the file.  */
 207       size_t todo;
 208       catalog->file_ptr = malloc (st.st_size);
 209       if (catalog->file_ptr == NULL)
 210         {
 211           catalog->status = nonexisting;
 212           goto unlock_return;
 213         }
 214       todo = st.st_size;
 215       /* Save read, handle partial reads.  */
 216       do
 217         {
 218           size_t now = __read (fd, (((char *) &catalog->file_ptr)
 219                                     + (st.st_size - todo)), todo);
 220           if (now == 0)
 221             {
 222               free ((void *) catalog->file_ptr);
 223               catalog->status = nonexisting;
 224               goto unlock_return;
 225             }
 226           todo -= now;
 227         }
 228       while (todo > 0);
 229       catalog->status = malloced;
 230     }
 231
 232   /* We don't need the file anymore.  */
 233   __close (fd);
 234   fd = -1;
 235
 236   /* Determine whether the file is a catalog file and if yes whether
 237      it is written using the correct byte order.  Else we have to swap
 238      the values.  */
 239   if (catalog->file_ptr->magic == CATGETS_MAGIC)
 240     swapping = 0;
 241   else if (catalog->file_ptr->magic == SWAPU32 (CATGETS_MAGIC))
 242     swapping = 1;
 243   else
 244     {
 245       /* Invalid file.  Free the resources and mark catalog as not
 246          usable.  */
 247       if (catalog->status == mmapped)
 248         __munmap ((void *) catalog->file_ptr, catalog->file_size);
 249       else
 250         free (catalog->file_ptr);
 251       catalog->status = nonexisting;
 252       goto unlock_return;
 253     }
 254
 255 #define SWAP(x) (swapping ? SWAPU32 (x) : (x))
 256
 257   /* Get dimensions of the used hashing table.  */
 258   catalog->plane_size = SWAP (catalog->file_ptr->plane_size);
 259   catalog->plane_depth = SWAP (catalog->file_ptr->plane_depth);
 260
 261   /* The file contains two versions of the pointer tables.  Pick the
 262      right one for the local byte order.  */
 263 #if __BYTE_ORDER == __LITTLE_ENDIAN
 264   catalog->name_ptr = &catalog->file_ptr->name_ptr[0];
 265 #elif __BYTE_ORDER == __BIG_ENDIAN
 266   catalog->name_ptr = &catalog->file_ptr->name_ptr[catalog->plane_size
 267                                                   * catalog->plane_depth
 268                                                   * 3];
 269 #else
 270 # error Cannot handle __BYTE_ORDER byte order
 271 #endif
 272
 273   /* The rest of the file contains all the strings.  They are
 274      addressed relative to the position of the first string.  */
 275   catalog->strings =
 276     (const char *) &catalog->file_ptr->name_ptr[catalog->plane_size
 277                                                * catalog->plane_depth * 3 * 2];
 278
 279   /* Release the lock again.  */
 280  unlock_return:
 281   if (fd != -1)
 282     __close (fd);
 283   __libc_lock_unlock (catalog->lock);
 284 }