glibc/catgets/open_catalog.c

322 lines
8.6 KiB
C

/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <byteswap.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include "catgetsinfo.h"
#define SWAPU32(w) bswap_32 (w)
void
__open_catalog (__nl_catd catalog)
{
int fd = -1;
struct stat st;
int swapping;
size_t cnt;
size_t max_offset;
size_t tab_size;
const char *lastp;
/* Make sure we are alone. */
__libc_lock_lock (catalog->lock);
/* Check whether there was no other thread faster. */
if (catalog->status != closed)
/* While we waited some other thread tried to open the catalog. */
goto unlock_return;
if (strchr (catalog->cat_name, '/') != NULL || catalog->nlspath == NULL)
fd = __open (catalog->cat_name, O_RDONLY);
else
{
const char *run_nlspath = catalog->nlspath;
#define ENOUGH(n) \
if (bufact + (n) >=bufmax) \
{ \
char *old_buf = buf; \
bufmax += 256 + (n); \
buf = (char *) alloca (bufmax); \
memcpy (buf, old_buf, bufact); \
}
/* The RUN_NLSPATH variable contains a colon separated list of
descriptions where we expect to find catalogs. We have to
recognize certain % substitutions and stop when we found the
first existing file. */
char *buf;
size_t bufact;
size_t bufmax;
size_t len;
buf = NULL;
bufmax = 0;
fd = -1;
while (*run_nlspath != '\0')
{
bufact = 0;
while (*run_nlspath != ':' && *run_nlspath != '\0')
if (*run_nlspath == '%')
{
const char *tmp;
++run_nlspath; /* We have seen the `%'. */
switch (*run_nlspath++)
{
case 'N':
/* Use the catalog name. */
len = strlen (catalog->cat_name);
ENOUGH (len);
memcpy (&buf[bufact], catalog->cat_name, len);
bufact += len;
break;
case 'L':
/* Use the current locale category value. */
len = strlen (catalog->env_var);
ENOUGH (len);
memcpy (&buf[bufact], catalog->env_var, len);
bufact += len;
break;
case 'l':
/* Use language element of locale category value. */
tmp = catalog->env_var;
do
{
ENOUGH (1);
buf[bufact++] = *tmp++;
}
while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
break;
case 't':
/* Use territory element of locale category value. */
tmp = catalog->env_var;
do
++tmp;
while (*tmp != '\0' && *tmp != '_' && *tmp != '.');
if (*tmp == '_')
{
++tmp;
do
{
ENOUGH (1);
buf[bufact++] = *tmp;
}
while (*tmp != '\0' && *tmp != '.');
}
break;
case 'c':
/* Use code set element of locale category value. */
tmp = catalog->env_var;
do
++tmp;
while (*tmp != '\0' && *tmp != '.');
if (*tmp == '.')
{
++tmp;
do
{
ENOUGH (1);
buf[bufact++] = *tmp;
}
while (*tmp != '\0');
}
break;
case '%':
ENOUGH (1);
buf[bufact++] = '%';
break;
default:
/* Unknown variable: ignore this path element. */
bufact = 0;
while (*run_nlspath != '\0' && *run_nlspath != ':')
++run_nlspath;
break;
}
}
else
{
ENOUGH (1);
buf[bufact++] = *run_nlspath++;
}
ENOUGH (1);
buf[bufact] = '\0';
if (bufact != 0)
{
fd = __open (buf, O_RDONLY);
if (fd >= 0)
break;
}
++run_nlspath;
}
}
/* Avoid dealing with directories and block devices */
if (fd < 0 || __fstat (fd, &st) < 0)
{
catalog->status = nonexisting;
goto unlock_return;
}
if (!S_ISREG (st.st_mode) || st.st_size < sizeof (struct catalog_obj))
{
/* `errno' is not set correctly but the file is not usable.
Use an reasonable error value. */
__set_errno (EINVAL);
catalog->status = nonexisting;
goto unlock_return;
}
#ifndef MAP_COPY
/* Linux seems to lack read-only copy-on-write. */
# define MAP_COPY MAP_PRIVATE
#endif
#ifndef MAP_FILE
/* Some systems do not have this flag; it is superfluous. */
# define MAP_FILE 0
#endif
#ifndef MAP_INHERIT
/* Some systems might lack this; they lose. */
# define MAP_INHERIT 0
#endif
catalog->file_size = st.st_size;
catalog->file_ptr =
(struct catalog_obj *) __mmap (NULL, st.st_size, PROT_READ,
MAP_FILE|MAP_COPY|MAP_INHERIT, fd, 0);
if (catalog->file_ptr != (struct catalog_obj *) MAP_FAILED)
/* Tell the world we managed to mmap the file. */
catalog->status = mmapped;
else
{
/* mmap failed perhaps because the system call is not
implemented. Try to load the file. */
size_t todo;
catalog->file_ptr = malloc (st.st_size);
if (catalog->file_ptr == NULL)
{
catalog->status = nonexisting;
goto unlock_return;
}
todo = st.st_size;
/* Save read, handle partial reads. */
do
{
size_t now = __read (fd, (((char *) &catalog->file_ptr)
+ (st.st_size - todo)), todo);
if (now == 0)
{
free ((void *) catalog->file_ptr);
catalog->status = nonexisting;
goto unlock_return;
}
todo -= now;
}
while (todo > 0);
catalog->status = malloced;
}
/* We don't need the file anymore. */
__close (fd);
fd = -1;
/* Determine whether the file is a catalog file and if yes whether
it is written using the correct byte order. Else we have to swap
the values. */
if (catalog->file_ptr->magic == CATGETS_MAGIC)
swapping = 0;
else if (catalog->file_ptr->magic == SWAPU32 (CATGETS_MAGIC))
swapping = 1;
else
{
invalid_file:
/* Invalid file. Free the resources and mark catalog as not
usable. */
if (catalog->status == mmapped)
__munmap ((void *) catalog->file_ptr, catalog->file_size);
else
free (catalog->file_ptr);
catalog->status = nonexisting;
goto unlock_return;
}
#define SWAP(x) (swapping ? SWAPU32 (x) : (x))
/* Get dimensions of the used hashing table. */
catalog->plane_size = SWAP (catalog->file_ptr->plane_size);
catalog->plane_depth = SWAP (catalog->file_ptr->plane_depth);
/* The file contains two versions of the pointer tables. Pick the
right one for the local byte order. */
#if __BYTE_ORDER == __LITTLE_ENDIAN
catalog->name_ptr = &catalog->file_ptr->name_ptr[0];
#elif __BYTE_ORDER == __BIG_ENDIAN
catalog->name_ptr = &catalog->file_ptr->name_ptr[catalog->plane_size
* catalog->plane_depth
* 3];
#else
# error Cannot handle __BYTE_ORDER byte order
#endif
/* The rest of the file contains all the strings. They are
addressed relative to the position of the first string. */
catalog->strings =
(const char *) &catalog->file_ptr->name_ptr[catalog->plane_size
* catalog->plane_depth * 3 * 2];
/* Determine the largest string offset mentioned in the table. */
max_offset = 0;
tab_size = 3 * catalog->plane_size * catalog->plane_depth;
for (cnt = 2; cnt < tab_size; cnt += 3)
if (catalog->name_ptr[cnt] > max_offset)
max_offset = catalog->name_ptr[cnt];
/* Now we can check whether the file is large enough to contain the
tables it says it contains. */
if (st.st_size <= (sizeof (struct catalog_obj) + 2 * tab_size + max_offset))
/* The last string is not contained in the file. */
goto invalid_file;
lastp = catalog->strings + max_offset;
max_offset = (st.st_size
- sizeof (struct catalog_obj) + 2 * tab_size + max_offset);
while (*lastp != '\0')
{
if (--max_offset == 0)
goto invalid_file;
++lastp;
}
/* Release the lock again. */
unlock_return:
if (fd != -1)
__close (fd);
__libc_lock_unlock (catalog->lock);
}