catgets/open_catalog.c

   1 /* Copyright (C) 1996-2000, 2001, 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper, <drepper@gnu.org>.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <byteswap.h>
  21 #include <endian.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #ifdef _POSIX_MAPPED_FILES
  28 # include <sys/mman.h>
  29 #endif
  30 #include <sys/stat.h>
  31
  32 #include "catgetsinfo.h"
  33 #include <not-cancel.h>
  34
  35
  36 #define SWAPU32(w) bswap_32 (w)
  37
  38
  39 int
  40 __open_catalog (const char *cat_name, const char *nlspath, const char *env_var,
  41                 __nl_catd catalog)
  42 {
  43   int fd = -1;
  44   struct stat64 st;
  45   int swapping;
  46   size_t cnt;
  47   size_t max_offset;
  48   size_t tab_size;
  49   const char *lastp;
  50   int result = -1;
  51
  52   if (strchr (cat_name, '/') != NULL || nlspath == NULL)
  53     fd = open_not_cancel_2 (cat_name, O_RDONLY);
  54   else
  55     {
  56       const char *run_nlspath = nlspath;
  57 #define ENOUGH(n)                                                             \
  58   if (__builtin_expect (bufact + (n) >= bufmax, 0))                           \
  59     {                                                                         \
  60       char *old_buf = buf;                                                    \
  61       bufmax += 256 + (n);                                                    \
  62       buf = (char *) alloca (bufmax);                                         \
  63       memcpy (buf, old_buf, bufact);                                          \
  64     }
  65
  66       /* The RUN_NLSPATH variable contains a colon separated list of
  67          descriptions where we expect to find catalogs.  We have to
  68          recognize certain % substitutions and stop when we found the
  69          first existing file.  */
  70       char *buf;
  71       size_t bufact;
  72       size_t bufmax;
  73       size_t len;
  74
  75       buf = NULL;
  76       bufmax = 0;
  77
  78       fd = -1;
  79       while (*run_nlspath != '\0')
  80         {
  81           bufact = 0;
  82
  83           if (*run_nlspath == ':')
  84             {
  85               /* Leading colon or adjacent colons - treat same as %N.  */
  86               len = strlen (cat_name);
  87               ENOUGH (len);
  88               memcpy (&buf[bufact], cat_name, len);
  89               bufact += len;
  90             }
  91           else
  92             while (*run_nlspath != ':' && *run_nlspath != '\0')
  93               if (*run_nlspath == '%')
  94                 {
  95                   const char *tmp;
  96
  97                   ++run_nlspath;        /* We have seen the `%'.  */
  98                   switch (*run_nlspath++)
  99                     {
 100                     case 'N':
 101                       /* Use the catalog name.  */
 102                       len = strlen (cat_name);
 103                       ENOUGH (len);
 104                       memcpy (&buf[bufact], cat_name, len);
 105                       bufact += len;
 106                       break;
 107                     case 'L':
 108                       /* Use the current locale category value.  */
 109                       len = strlen (env_var);
 110                       ENOUGH (len);
 111                       memcpy (&buf[bufact], env_var, len);
 112                       bufact += len;
 113                       break;
 114                     case 'l':
 115                       /* Use language element of locale category value.  */
 116                       tmp = env_var;
 117                       do
 118                         {
 119                           ENOUGH (1);
 120                           buf[bufact++] = *tmp++;
 121                         }
 122                       while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
 123                       break;
 124                     case 't':
 125                       /* Use territory element of locale category value.  */
 126                       tmp = env_var;
 127                       do
 128                         ++tmp;
 129                       while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
 130                       if (*tmp == '_')
 131                         {
 132                           ++tmp;
 133                           do
 134                             {
 135                               ENOUGH (1);
 136                               buf[bufact++] = *tmp++;
 137                             }
 138                           while (*tmp != '\0' && *tmp != '.');
 139                         }
 140                       break;
 141                     case 'c':
 142                       /* Use code set element of locale category value.  */
 143                       tmp = env_var;
 144                       do
 145                         ++tmp;
 146                       while (*tmp != '\0' && *tmp != '.');
 147                       if (*tmp == '.')
 148                         {
 149                           ++tmp;
 150                           do
 151                             {
 152                               ENOUGH (1);
 153                               buf[bufact++] = *tmp++;
 154                             }
 155                           while (*tmp != '\0');
 156                         }
 157                       break;
 158                     case '%':
 159                       ENOUGH (1);
 160                       buf[bufact++] = '%';
 161                       break;
 162                     default:
 163                       /* Unknown variable: ignore this path element.  */
 164                       bufact = 0;
 165                       while (*run_nlspath != '\0' && *run_nlspath != ':')
 166                         ++run_nlspath;
 167                       break;
 168                     }
 169                 }
 170               else
 171                 {
 172                   ENOUGH (1);
 173                   buf[bufact++] = *run_nlspath++;
 174                 }
 175
 176           ENOUGH (1);
 177           buf[bufact] = '\0';
 178
 179           if (bufact != 0)
 180             {
 181               fd = open_not_cancel_2 (buf, O_RDONLY);
 182               if (fd >= 0)
 183                 break;
 184             }
 185
 186           ++run_nlspath;
 187         }
 188     }
 189
 190   /* Avoid dealing with directories and block devices */
 191   if (__builtin_expect (fd, 0) < 0)
 192     return -1;
 193
 194   if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0) < 0)
 195     goto close_unlock_return;
 196
 197   if (__builtin_expect (!S_ISREG (st.st_mode), 0)
 198       || (size_t) st.st_size < sizeof (struct catalog_obj))
 199     {
 200       /* `errno' is not set correctly but the file is not usable.
 201          Use an reasonable error value.  */
 202       __set_errno (EINVAL);
 203       goto close_unlock_return;
 204     }
 205
 206   catalog->file_size = st.st_size;
 207 #ifdef _POSIX_MAPPED_FILES
 208 # ifndef MAP_COPY
 209     /* Linux seems to lack read-only copy-on-write.  */
 210 #  define MAP_COPY MAP_PRIVATE
 211 # endif
 212 # ifndef MAP_FILE
 213     /* Some systems do not have this flag; it is superfluous.  */
 214 #  define MAP_FILE 0
 215 # endif
 216   catalog->file_ptr =
 217     (struct catalog_obj *) __mmap (NULL, st.st_size, PROT_READ,
 218                                    MAP_FILE|MAP_COPY, fd, 0);
 219   if (__builtin_expect (catalog->file_ptr != (struct catalog_obj *) MAP_FAILED,
 220                         1))
 221     /* Tell the world we managed to mmap the file.  */
 222     catalog->status = mmapped;
 223   else
 224 #endif /* _POSIX_MAPPED_FILES */
 225     {
 226       /* mmap failed perhaps because the system call is not
 227          implemented.  Try to load the file.  */
 228       size_t todo;
 229       catalog->file_ptr = malloc (st.st_size);
 230       if (catalog->file_ptr == NULL)
 231         goto close_unlock_return;
 232
 233       todo = st.st_size;
 234       /* Save read, handle partial reads.  */
 235       do
 236         {
 237           size_t now = read_not_cancel (fd, (((char *) catalog->file_ptr)
 238                                              + (st.st_size - todo)), todo);
 239           if (now == 0 || now == (size_t) -1)
 240             {
 241 #ifdef EINTR
 242               if (now == (size_t) -1 && errno == EINTR)
 243                 continue;
 244 #endif
 245               free ((void *) catalog->file_ptr);
 246               goto close_unlock_return;
 247             }
 248           todo -= now;
 249         }
 250       while (todo > 0);
 251       catalog->status = malloced;
 252     }
 253
 254   /* Determine whether the file is a catalog file and if yes whether
 255      it is written using the correct byte order.  Else we have to swap
 256      the values.  */
 257   if (__builtin_expect (catalog->file_ptr->magic == CATGETS_MAGIC, 1))
 258     swapping = 0;
 259   else if (catalog->file_ptr->magic == SWAPU32 (CATGETS_MAGIC))
 260     swapping = 1;
 261   else
 262     {
 263     invalid_file:
 264       /* Invalid file.  Free the resources and mark catalog as not
 265          usable.  */
 266 #ifdef _POSIX_MAPPED_FILES
 267       if (catalog->status == mmapped)
 268         __munmap ((void *) catalog->file_ptr, catalog->file_size);
 269       else
 270 #endif  /* _POSIX_MAPPED_FILES */
 271         free (catalog->file_ptr);
 272       goto close_unlock_return;
 273     }
 274
 275 #define SWAP(x) (swapping ? SWAPU32 (x) : (x))
 276
 277   /* Get dimensions of the used hashing table.  */
 278   catalog->plane_size = SWAP (catalog->file_ptr->plane_size);
 279   catalog->plane_depth = SWAP (catalog->file_ptr->plane_depth);
 280
 281   /* The file contains two versions of the pointer tables.  Pick the
 282      right one for the local byte order.  */
 283 #if __BYTE_ORDER == __LITTLE_ENDIAN
 284   catalog->name_ptr = &catalog->file_ptr->name_ptr[0];
 285 #elif __BYTE_ORDER == __BIG_ENDIAN
 286   catalog->name_ptr = &catalog->file_ptr->name_ptr[catalog->plane_size
 287                                                   * catalog->plane_depth
 288                                                   * 3];
 289 #else
 290 # error Cannot handle __BYTE_ORDER byte order
 291 #endif
 292
 293   /* The rest of the file contains all the strings.  They are
 294      addressed relative to the position of the first string.  */
 295   catalog->strings =
 296     (const char *) &catalog->file_ptr->name_ptr[catalog->plane_size
 297                                                * catalog->plane_depth * 3 * 2];
 298
 299   /* Determine the largest string offset mentioned in the table.  */
 300   max_offset = 0;
 301   tab_size = 3 * catalog->plane_size * catalog->plane_depth;
 302   for (cnt = 2; cnt < tab_size; cnt += 3)
 303     if (catalog->name_ptr[cnt] > max_offset)
 304       max_offset = catalog->name_ptr[cnt];
 305
 306   /* Now we can check whether the file is large enough to contain the
 307      tables it says it contains.  */
 308   if ((size_t) st.st_size
 309       <= (sizeof (struct catalog_obj) + 2 * tab_size + max_offset))
 310     /* The last string is not contained in the file.  */
 311     goto invalid_file;
 312
 313   lastp = catalog->strings + max_offset;
 314   max_offset = (st.st_size
 315                 - sizeof (struct catalog_obj) + 2 * tab_size + max_offset);
 316   while (*lastp != '\0')
 317     {
 318       if (--max_offset == 0)
 319         goto invalid_file;
 320       ++lastp;
 321     }
 322
 323   /* We succeeded.  */
 324   result = 0;
 325
 326   /* Release the lock again.  */
 327  close_unlock_return:
 328   close_not_cancel_no_status (fd);
 329
 330   return result;
 331 }
 332 libc_hidden_def (__open_catalog)