/* Handle configuration data.
Copyright (C) 1997-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <search.h>
#include <stddef.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <libc-lock.h>
#include <gconv_int.h>
/* This is the default path where we look for module lists. */
static const char default_gconv_path[] = GCONV_PATH;
/* The path elements, as determined by the __gconv_get_path function.
All path elements end in a slash. */
struct path_elem *__gconv_path_elem;
/* Maximum length of a single path element in __gconv_path_elem. */
size_t __gconv_max_path_elem_len;
/* We use the following struct if we couldn't allocate memory. */
static const struct path_elem empty_path_elem = { NULL, 0 };
/* Name of the file containing the module information in the directories
along the path. */
static const char gconv_conf_filename[] = "gconv-modules";
/* Filename extension for the modules. */
#ifndef MODULE_EXT
# define MODULE_EXT ".so"
#endif
static const char gconv_module_ext[] = MODULE_EXT;
/* We have a few builtin transformations. */
static struct gconv_module builtin_modules[] =
{
#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
MinF, MaxF, MinT, MaxT) \
{ \
.from_string = From, \
.to_string = To, \
.cost_hi = Cost, \
.cost_lo = INT_MAX, \
.module_name = Name \
},
#define BUILTIN_ALIAS(From, To)
#include "gconv_builtin.h"
#undef BUILTIN_TRANSFORMATION
#undef BUILTIN_ALIAS
};
static const char builtin_aliases[] =
{
#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
MinF, MaxF, MinT, MaxT)
#define BUILTIN_ALIAS(From, To) From "\0" To "\0"
#include "gconv_builtin.h"
#undef BUILTIN_TRANSFORMATION
#undef BUILTIN_ALIAS
};
#include <libio/libioP.h>
#define __getdelim(line, len, c, fp) _IO_getdelim (line, len, c, fp)
/* Value of the GCONV_PATH environment variable. */
const char *__gconv_path_envvar;
/* Test whether there is already a matching module known. */
static int
detect_conflict (const char *alias)
{
struct gconv_module *node = __gconv_modules_db;
while (node != NULL)
{
int cmpres = strcmp (alias, node->from_string);
if (cmpres == 0)
/* We have a conflict. */
return 1;
else if (cmpres < 0)
node = node->left;
else
node = node->right;
}
return node != NULL;
}
/* The actual code to add aliases. */
static void
add_alias2 (const char *from, const char *to, const char *wp, void *modules)
{
/* Test whether this alias conflicts with any available module. */
if (detect_conflict (from))
/* It does conflict, don't add the alias. */
return;
struct gconv_alias *new_alias = (struct gconv_alias *)
malloc (sizeof (struct gconv_alias) + (wp - from));
if (new_alias != NULL)
{
void **inserted;
new_alias->fromname = memcpy ((char *) new_alias
+ sizeof (struct gconv_alias),
from, wp - from);
new_alias->toname = new_alias->fromname + (to - from);
inserted = (void **) __tsearch (new_alias, &__gconv_alias_db,
__gconv_alias_compare);
if (inserted == NULL || *inserted != new_alias)
/* Something went wrong, free this entry. */
free (new_alias);
}
}
/* Add new alias. */
static void
add_alias (char *rp, void *modules)
{
/* We now expect two more string. The strings are normalized
(converted to UPPER case) and strored in the alias database. */
char *from, *to, *wp;
while (__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
from = wp = rp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
*wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
if (*rp == '\0')
/* There is no `to' string on the line. Ignore it. */
return;
*wp++ = '\0';
to = ++rp;
while (__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
*wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
if (to == wp)
/* No `to' string, ignore the line. */
return;
*wp++ = '\0';
add_alias2 (from, to, wp, modules);
}
/* Insert a data structure for a new module in the search tree. */
static void
insert_module (struct gconv_module *newp, int tobefreed)
{
struct gconv_module **rootp = &__gconv_modules_db;
while (*rootp != NULL)
{
struct gconv_module *root = *rootp;
int cmpres;
cmpres = strcmp (newp->from_string, root->from_string);
if (cmpres == 0)
{
/* Both strings are identical. Insert the string at the
end of the `same' list if it is not already there. */
while (strcmp (newp->from_string, root->from_string) != 0
|| strcmp (newp->to_string, root->to_string) != 0)
{
rootp = &root->same;
root = *rootp;
if (root == NULL)
break;
}
if (root != NULL)
{
/* This is a no new conversion. But maybe the cost is
better. */
if (newp->cost_hi < root->cost_hi
|| (newp->cost_hi == root->cost_hi
&& newp->cost_lo < root->cost_lo))
{
newp->left = root->left;
newp->right = root->right;
newp->same = root->same;
*rootp = newp;
free (root);
}
else if (tobefreed)
free (newp);
return;
}
break;
}
else if (cmpres < 0)
rootp = &root->left;
else
rootp = &root->right;
}
/* Plug in the new node here. */
*rootp = newp;
}
/* Add new module. */
static void
add_module (char *rp, const char *directory, size_t dir_len, void **modules,
size_t *nmodules, int modcounter)
{
/* We expect now
1. `from' name
2. `to' name
3. filename of the module
4. an optional cost value
*/
struct gconv_alias fake_alias;
struct gconv_module *new_module;
char *from, *to, *module, *wp;
int need_ext;
int cost_hi;
while (__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
from = rp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
{
*rp = __toupper_l (*rp, _nl_C_locobj_ptr);
++rp;
}
if (*rp == '\0')
return;
*rp++ = '\0';
to = wp = rp;
while (__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
*wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
if (*rp == '\0')
return;
*wp++ = '\0';
do
++rp;
while (__isspace_l (*rp, _nl_C_locobj_ptr));
module = wp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
*wp++ = *rp++;
if (*rp == '\0')
{
/* There is no cost, use one by default. */
*wp++ = '\0';
cost_hi = 1;
}
else
{
/* There might be a cost value. */
char *endp;
*wp++ = '\0';
cost_hi = strtol (rp, &endp, 10);
if (rp == endp || cost_hi < 1)
/* No useful information. */
cost_hi = 1;
}
if (module[0] == '\0')
/* No module name given. */
return;
if (module[0] == '/')
dir_len = 0;
/* See whether we must add the ending. */
need_ext = 0;
if (wp - module < (ptrdiff_t) sizeof (gconv_module_ext)
|| memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext,
sizeof (gconv_module_ext)) != 0)
/* We must add the module extension. */
need_ext = sizeof (gconv_module_ext) - 1;
/* See whether we have already an alias with this name defined. */
fake_alias.fromname = strndupa (from, to - from);
if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare) != NULL)
/* This module duplicates an alias. */
return;
new_module = (struct gconv_module *) calloc (1,
sizeof (struct gconv_module)
+ (wp - from)
+ dir_len + need_ext);
if (new_module != NULL)
{
char *tmp;
new_module->from_string = tmp = (char *) (new_module + 1);
tmp = __mempcpy (tmp, from, to - from);
new_module->to_string = tmp;
tmp = __mempcpy (tmp, to, module - to);
new_module->cost_hi = cost_hi;
new_module->cost_lo = modcounter;
new_module->module_name = tmp;
if (dir_len != 0)
tmp = __mempcpy (tmp, directory, dir_len);
tmp = __mempcpy (tmp, module, wp - module);
if (need_ext)
memcpy (tmp - 1, gconv_module_ext, sizeof (gconv_module_ext));
/* Now insert the new module data structure in our search tree. */
insert_module (new_module, 1);
}
}
/* Read the next configuration file. */
static void
read_conf_file (const char *filename, const char *directory, size_t dir_len,
void **modules, size_t *nmodules)
{
/* Note the file is opened with cancellation in the I/O functions
disabled. */
FILE *fp = fopen (filename, "rce");
char *line = NULL;
size_t line_len = 0;
static int modcounter;
/* Don't complain if a file is not present or readable, simply silently
ignore it. */
if (fp == NULL)
return;
/* No threads reading from this stream. */
__fsetlocking (fp, FSETLOCKING_BYCALLER);
/* Process the known entries of the file. Comments start with `#' and
end with the end of the line. Empty lines are ignored. */
while (!__feof_unlocked (fp))
{
char *rp, *endp, *word;
ssize_t n = __getdelim (&line, &line_len, '\n', fp);
if (n < 0)
/* An error occurred. */
break;
rp = line;
/* Terminate the line (excluding comments or newline) by an NUL byte
to simplify the following code. */
endp = strchr (rp, '#');
if (endp != NULL)
*endp = '\0';
else
if (rp[n - 1] == '\n')
rp[n - 1] = '\0';
while (__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
/* If this is an empty line go on with the next one. */
if (rp == endp)
continue;
word = rp;
while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
++rp;
if (rp - word == sizeof ("alias") - 1
&& memcmp (word, "alias", sizeof ("alias") - 1) == 0)
add_alias (rp, *modules);
else if (rp - word == sizeof ("module") - 1
&& memcmp (word, "module", sizeof ("module") - 1) == 0)
add_module (rp, directory, dir_len, modules, nmodules, modcounter++);
/* else */
/* Otherwise ignore the line. */
}
free (line);
fclose (fp);
}
/* Determine the directories we are looking for data in. */
void
__gconv_get_path (void)
{
struct path_elem *result;
__libc_lock_define_initialized (static, lock);
__libc_lock_lock (lock);
/* Make sure there wasn't a second thread doing it already. */
result = (struct path_elem *) __gconv_path_elem;
if (result == NULL)
{
/* Determine the complete path first. */
char *gconv_path;
size_t gconv_path_len;
char *elem;
char *oldp;
char *cp;
int nelems;
char *cwd;
size_t cwdlen;
if (__gconv_path_envvar == NULL)
{
/* No user-defined path. Make a modifiable copy of the
default path. */
gconv_path = strdupa (default_gconv_path);
gconv_path_len = sizeof (default_gconv_path);
cwd = NULL;
cwdlen = 0;
}
else
{
/* Append the default path to the user-defined path. */
size_t user_len = strlen (__gconv_path_envvar);
gconv_path_len = user_len + 1 + sizeof (default_gconv_path);
gconv_path = alloca (gconv_path_len);
__mempcpy (__mempcpy (__mempcpy (gconv_path, __gconv_path_envvar,
user_len),
":", 1),
default_gconv_path, sizeof (default_gconv_path));
cwd = __getcwd (NULL, 0);
cwdlen = __glibc_unlikely (cwd == NULL) ? 0 : strlen (cwd);
}
assert (default_gconv_path[0] == '/');
/* In a first pass we calculate the number of elements. */
oldp = NULL;
cp = strchr (gconv_path, ':');
nelems = 1;
while (cp != NULL)
{
if (cp != oldp + 1)
++nelems;
oldp = cp;
cp = strchr (cp + 1, ':');
}
/* Allocate the memory for the result. */
result = (struct path_elem *) malloc ((nelems + 1)
* sizeof (struct path_elem)
+ gconv_path_len + nelems
+ (nelems - 1) * (cwdlen + 1));
if (result != NULL)
{
char *strspace = (char *) &result[nelems + 1];
int n = 0;
/* Separate the individual parts. */
__gconv_max_path_elem_len = 0;
elem = __strtok_r (gconv_path, ":", &gconv_path);
assert (elem != NULL);
do
{
result[n].name = strspace;
if (elem[0] != '/')
{
assert (cwd != NULL);
strspace = __mempcpy (strspace, cwd, cwdlen);
*strspace++ = '/';
}
strspace = __stpcpy (strspace, elem);
if (strspace[-1] != '/')
*strspace++ = '/';
result[n].len = strspace - result[n].name;
if (result[n].len > __gconv_max_path_elem_len)
__gconv_max_path_elem_len = result[n].len;
*strspace++ = '\0';
++n;
}
while ((elem = __strtok_r (NULL, ":", &gconv_path)) != NULL);
result[n].name = NULL;
result[n].len = 0;
}
__gconv_path_elem = result ?: (struct path_elem *) &empty_path_elem;
free (cwd);
}
__libc_lock_unlock (lock);
}
/* Read all configuration files found in the user-specified and the default
path. */
void
attribute_hidden
__gconv_read_conf (void)
{
void *modules = NULL;
size_t nmodules = 0;
int save_errno = errno;
size_t cnt;
/* First see whether we should use the cache. */
if (__gconv_load_cache () == 0)
{
/* Yes, we are done. */
__set_errno (save_errno);
return;
}
#ifndef STATIC_GCONV
/* Find out where we have to look. */
if (__gconv_path_elem == NULL)
__gconv_get_path ();
for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt)
{
const char *elem = __gconv_path_elem[cnt].name;
size_t elem_len = __gconv_path_elem[cnt].len;
char *filename;
/* No slash needs to be inserted between elem and gconv_conf_filename;
elem already ends in a slash. */
filename = alloca (elem_len + sizeof (gconv_conf_filename));
__mempcpy (__mempcpy (filename, elem, elem_len),
gconv_conf_filename, sizeof (gconv_conf_filename));
/* Read the next configuration file. */
read_conf_file (filename, elem, elem_len, &modules, &nmodules);
}
#endif
/* Add the internal modules. */
for (cnt = 0; cnt < sizeof (builtin_modules) / sizeof (builtin_modules[0]);
++cnt)
{
struct gconv_alias fake_alias;
fake_alias.fromname = (char *) builtin_modules[cnt].from_string;
if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare)
!= NULL)
/* It'll conflict so don't add it. */
continue;
insert_module (&builtin_modules[cnt], 0);
}
/* Add aliases for builtin conversions. */
const char *cp = builtin_aliases;
do
{
const char *from = cp;
const char *to = __rawmemchr (from, '\0') + 1;
cp = __rawmemchr (to, '\0') + 1;
add_alias2 (from, to, cp, modules);
}
while (*cp != '\0');
/* Restore the error number. */
__set_errno (save_errno);
}
/* Free all resources if necessary. */
libc_freeres_fn (free_mem)
{
if (__gconv_path_elem != NULL && __gconv_path_elem != &empty_path_elem)
free ((void *) __gconv_path_elem);
}