1 /* Handle configuration data.
2 Copyright (C) 1997-2003, 2005, 2006, 2011 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
29 #include <stdio_ext.h>
33 #include <sys/param.h>
35 #include <bits/libc-lock.h>
36 #include <gconv_int.h>
39 /* This is the default path where we look for module lists. */
40 static const char default_gconv_path[] = GCONV_PATH;
42 /* The path elements, as determined by the __gconv_get_path function.
43 All path elements end in a slash. */
44 struct path_elem *__gconv_path_elem;
45 /* Maximum length of a single path element in __gconv_path_elem. */
46 size_t __gconv_max_path_elem_len;
48 /* We use the following struct if we couldn't allocate memory. */
49 static const struct path_elem empty_path_elem = { NULL, 0 };
51 /* Name of the file containing the module information in the directories
53 static const char gconv_conf_filename[] = "gconv-modules";
55 /* Filename extension for the modules. */
57 # define MODULE_EXT ".so"
59 static const char gconv_module_ext[] = MODULE_EXT;
61 /* We have a few builtin transformations. */
62 static struct gconv_module builtin_modules[] =
64 #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
65 MinF, MaxF, MinT, MaxT) \
67 .from_string = From, \
73 #define BUILTIN_ALIAS(From, To)
75 #include "gconv_builtin.h"
77 #undef BUILTIN_TRANSFORMATION
81 static const char builtin_aliases[] =
83 #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
84 MinF, MaxF, MinT, MaxT)
85 #define BUILTIN_ALIAS(From, To) From "\0" To "\0"
87 #include "gconv_builtin.h"
89 #undef BUILTIN_TRANSFORMATION
93 #include <libio/libioP.h>
94 #define __getdelim(line, len, c, fp) _IO_getdelim (line, len, c, fp)
97 /* Value of the GCONV_PATH environment variable. */
98 const char *__gconv_path_envvar;
101 /* Test whether there is already a matching module known. */
104 detect_conflict (const char *alias)
106 struct gconv_module *node = __gconv_modules_db;
110 int cmpres = strcmp (alias, node->from_string);
113 /* We have a conflict. */
125 /* The actual code to add aliases. */
127 add_alias2 (const char *from, const char *to, const char *wp, void *modules)
129 /* Test whether this alias conflicts with any available module. */
130 if (detect_conflict (from))
131 /* It does conflict, don't add the alias. */
134 struct gconv_alias *new_alias = (struct gconv_alias *)
135 malloc (sizeof (struct gconv_alias) + (wp - from));
136 if (new_alias != NULL)
140 new_alias->fromname = memcpy ((char *) new_alias
141 + sizeof (struct gconv_alias),
143 new_alias->toname = new_alias->fromname + (to - from);
145 inserted = (void **) __tsearch (new_alias, &__gconv_alias_db,
146 __gconv_alias_compare);
147 if (inserted == NULL || *inserted != new_alias)
148 /* Something went wrong, free this entry. */
156 add_alias (char *rp, void *modules)
158 /* We now expect two more string. The strings are normalized
159 (converted to UPPER case) and strored in the alias database. */
160 char *from, *to, *wp;
162 while (__isspace_l (*rp, _nl_C_locobj_ptr))
165 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
166 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
168 /* There is no `to' string on the line. Ignore it. */
172 while (__isspace_l (*rp, _nl_C_locobj_ptr))
174 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
175 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
177 /* No `to' string, ignore the line. */
181 add_alias2 (from, to, wp, modules);
185 /* Insert a data structure for a new module in the search tree. */
188 insert_module (struct gconv_module *newp, int tobefreed)
190 struct gconv_module **rootp = &__gconv_modules_db;
192 while (*rootp != NULL)
194 struct gconv_module *root = *rootp;
197 cmpres = strcmp (newp->from_string, root->from_string);
200 /* Both strings are identical. Insert the string at the
201 end of the `same' list if it is not already there. */
202 while (strcmp (newp->from_string, root->from_string) != 0
203 || strcmp (newp->to_string, root->to_string) != 0)
213 /* This is a no new conversion. But maybe the cost is
215 if (newp->cost_hi < root->cost_hi
216 || (newp->cost_hi == root->cost_hi
217 && newp->cost_lo < root->cost_lo))
219 newp->left = root->left;
220 newp->right = root->right;
221 newp->same = root->same;
236 rootp = &root->right;
239 /* Plug in the new node here. */
244 /* Add new module. */
247 add_module (char *rp, const char *directory, size_t dir_len, void **modules,
248 size_t *nmodules, int modcounter)
253 3. filename of the module
254 4. an optional cost value
256 struct gconv_alias fake_alias;
257 struct gconv_module *new_module;
258 char *from, *to, *module, *wp;
262 while (__isspace_l (*rp, _nl_C_locobj_ptr))
265 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
267 *rp = __toupper_l (*rp, _nl_C_locobj_ptr);
274 while (__isspace_l (*rp, _nl_C_locobj_ptr))
276 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
277 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
283 while (__isspace_l (*rp, _nl_C_locobj_ptr));
285 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
289 /* There is no cost, use one by default. */
295 /* There might be a cost value. */
299 cost_hi = strtol (rp, &endp, 10);
300 if (rp == endp || cost_hi < 1)
301 /* No useful information. */
305 if (module[0] == '\0')
306 /* No module name given. */
308 if (module[0] == '/')
311 /* See whether we must add the ending. */
313 if (wp - module < (ptrdiff_t) sizeof (gconv_module_ext)
314 || memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext,
315 sizeof (gconv_module_ext)) != 0)
316 /* We must add the module extension. */
317 need_ext = sizeof (gconv_module_ext) - 1;
319 /* See whether we have already an alias with this name defined. */
320 fake_alias.fromname = strndupa (from, to - from);
322 if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare) != NULL)
323 /* This module duplicates an alias. */
326 new_module = (struct gconv_module *) calloc (1,
327 sizeof (struct gconv_module)
329 + dir_len + need_ext);
330 if (new_module != NULL)
334 new_module->from_string = tmp = (char *) (new_module + 1);
335 tmp = __mempcpy (tmp, from, to - from);
337 new_module->to_string = tmp;
338 tmp = __mempcpy (tmp, to, module - to);
340 new_module->cost_hi = cost_hi;
341 new_module->cost_lo = modcounter;
343 new_module->module_name = tmp;
346 tmp = __mempcpy (tmp, directory, dir_len);
348 tmp = __mempcpy (tmp, module, wp - module);
351 memcpy (tmp - 1, gconv_module_ext, sizeof (gconv_module_ext));
353 /* Now insert the new module data structure in our search tree. */
354 insert_module (new_module, 1);
359 /* Read the next configuration file. */
362 read_conf_file (const char *filename, const char *directory, size_t dir_len,
363 void **modules, size_t *nmodules)
365 /* Note the file is opened with cancellation in the I/O functions
367 FILE *fp = fopen (filename, "rc");
370 static int modcounter;
372 /* Don't complain if a file is not present or readable, simply silently
377 /* No threads reading from this stream. */
378 __fsetlocking (fp, FSETLOCKING_BYCALLER);
380 /* Process the known entries of the file. Comments start with `#' and
381 end with the end of the line. Empty lines are ignored. */
382 while (!feof_unlocked (fp))
384 char *rp, *endp, *word;
385 ssize_t n = __getdelim (&line, &line_len, '\n', fp);
387 /* An error occurred. */
391 /* Terminate the line (excluding comments or newline) by an NUL byte
392 to simplify the following code. */
393 endp = strchr (rp, '#');
397 if (rp[n - 1] == '\n')
400 while (__isspace_l (*rp, _nl_C_locobj_ptr))
403 /* If this is an empty line go on with the next one. */
408 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
411 if (rp - word == sizeof ("alias") - 1
412 && memcmp (word, "alias", sizeof ("alias") - 1) == 0)
413 add_alias (rp, *modules);
414 else if (rp - word == sizeof ("module") - 1
415 && memcmp (word, "module", sizeof ("module") - 1) == 0)
416 add_module (rp, directory, dir_len, modules, nmodules, modcounter++);
418 /* Otherwise ignore the line. */
427 /* Determine the directories we are looking for data in. */
430 __gconv_get_path (void)
432 struct path_elem *result;
433 __libc_lock_define_initialized (static, lock);
435 __libc_lock_lock (lock);
437 /* Make sure there wasn't a second thread doing it already. */
438 result = (struct path_elem *) __gconv_path_elem;
441 /* Determine the complete path first. */
443 size_t gconv_path_len;
451 if (__gconv_path_envvar == NULL)
453 /* No user-defined path. Make a modifiable copy of the
455 gconv_path = strdupa (default_gconv_path);
456 gconv_path_len = sizeof (default_gconv_path);
462 /* Append the default path to the user-defined path. */
463 size_t user_len = strlen (__gconv_path_envvar);
465 gconv_path_len = user_len + 1 + sizeof (default_gconv_path);
466 gconv_path = alloca (gconv_path_len);
467 __mempcpy (__mempcpy (__mempcpy (gconv_path, __gconv_path_envvar,
470 default_gconv_path, sizeof (default_gconv_path));
471 cwd = __getcwd (NULL, 0);
472 cwdlen = strlen (cwd);
474 assert (default_gconv_path[0] == '/');
476 /* In a first pass we calculate the number of elements. */
478 cp = strchr (gconv_path, ':');
485 cp = strchr (cp + 1, ':');
488 /* Allocate the memory for the result. */
489 result = (struct path_elem *) malloc ((nelems + 1)
490 * sizeof (struct path_elem)
491 + gconv_path_len + nelems
492 + (nelems - 1) * (cwdlen + 1));
495 char *strspace = (char *) &result[nelems + 1];
498 /* Separate the individual parts. */
499 __gconv_max_path_elem_len = 0;
500 elem = __strtok_r (gconv_path, ":", &gconv_path);
501 assert (elem != NULL);
504 result[n].name = strspace;
507 assert (cwd != NULL);
508 strspace = __mempcpy (strspace, cwd, cwdlen);
511 strspace = __stpcpy (strspace, elem);
512 if (strspace[-1] != '/')
515 result[n].len = strspace - result[n].name;
516 if (result[n].len > __gconv_max_path_elem_len)
517 __gconv_max_path_elem_len = result[n].len;
522 while ((elem = __strtok_r (NULL, ":", &gconv_path)) != NULL);
524 result[n].name = NULL;
528 __gconv_path_elem = result ?: (struct path_elem *) &empty_path_elem;
533 __libc_lock_unlock (lock);
537 /* Read all configuration files found in the user-specified and the default
541 __gconv_read_conf (void)
543 void *modules = NULL;
545 int save_errno = errno;
548 /* First see whether we should use the cache. */
549 if (__gconv_load_cache () == 0)
551 /* Yes, we are done. */
552 __set_errno (save_errno);
557 /* Find out where we have to look. */
558 if (__gconv_path_elem == NULL)
561 for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt)
563 const char *elem = __gconv_path_elem[cnt].name;
564 size_t elem_len = __gconv_path_elem[cnt].len;
567 /* No slash needs to be inserted between elem and gconv_conf_filename;
568 elem already ends in a slash. */
569 filename = alloca (elem_len + sizeof (gconv_conf_filename));
570 __mempcpy (__mempcpy (filename, elem, elem_len),
571 gconv_conf_filename, sizeof (gconv_conf_filename));
573 /* Read the next configuration file. */
574 read_conf_file (filename, elem, elem_len, &modules, &nmodules);
578 /* Add the internal modules. */
579 for (cnt = 0; cnt < sizeof (builtin_modules) / sizeof (builtin_modules[0]);
582 struct gconv_alias fake_alias;
584 fake_alias.fromname = (char *) builtin_modules[cnt].from_string;
586 if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare)
588 /* It'll conflict so don't add it. */
591 insert_module (&builtin_modules[cnt], 0);
594 /* Add aliases for builtin conversions. */
595 const char *cp = builtin_aliases;
598 const char *from = cp;
599 const char *to = __rawmemchr (from, '\0') + 1;
600 cp = __rawmemchr (to, '\0') + 1;
602 add_alias2 (from, to, cp, modules);
606 /* Restore the error number. */
607 __set_errno (save_errno);
612 /* Free all resources if necessary. */
613 libc_freeres_fn (free_mem)
615 if (__gconv_path_elem != NULL && __gconv_path_elem != &empty_path_elem)
616 free ((void *) __gconv_path_elem);