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[glibc.git] / iconv / gconv_conf.c
blob2023beb2671ca5ac9d9867cad9521e63d9a75d5c
1 /* Handle configuration data.
2 Copyright (C) 1997-2003, 2005, 2006 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
19 02111-1307 USA. */
21 #include <assert.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <limits.h>
25 #include <locale.h>
26 #include <search.h>
27 #include <stddef.h>
28 #include <stdio.h>
29 #include <stdio_ext.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.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
52 along the path. */
53 static const char gconv_conf_filename[] = "gconv-modules";
55 /* Filename extension for the modules. */
56 #ifndef MODULE_EXT
57 # define MODULE_EXT ".so"
58 #endif
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) \
66 { \
67 .from_string = From, \
68 .to_string = To, \
69 .cost_hi = Cost, \
70 .cost_lo = INT_MAX, \
71 .module_name = Name \
73 #define BUILTIN_ALIAS(From, To)
75 #include "gconv_builtin.h"
77 #undef BUILTIN_TRANSFORMATION
78 #undef BUILTIN_ALIAS
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
90 #undef BUILTIN_ALIAS
93 #ifdef USE_IN_LIBIO
94 # include <libio/libioP.h>
95 # define __getdelim(line, len, c, fp) _IO_getdelim (line, len, c, fp)
96 #endif
99 /* Value of the GCONV_PATH environment variable. */
100 const char *__gconv_path_envvar;
103 /* Test whether there is already a matching module known. */
104 static int
105 internal_function
106 detect_conflict (const char *alias)
108 struct gconv_module *node = __gconv_modules_db;
110 while (node != NULL)
112 int cmpres = strcmp (alias, node->from_string);
114 if (cmpres == 0)
115 /* We have a conflict. */
116 return 1;
117 else if (cmpres < 0)
118 node = node->left;
119 else
120 node = node->right;
123 return node != NULL;
127 /* The actual code to add aliases. */
128 static void
129 add_alias2 (const char *from, const char *to, const char *wp, void *modules)
131 /* Test whether this alias conflicts with any available module. */
132 if (detect_conflict (from))
133 /* It does conflict, don't add the alias. */
134 return;
136 struct gconv_alias *new_alias = (struct gconv_alias *)
137 malloc (sizeof (struct gconv_alias) + (wp - from));
138 if (new_alias != NULL)
140 void **inserted;
142 new_alias->fromname = memcpy ((char *) new_alias
143 + sizeof (struct gconv_alias),
144 from, wp - from);
145 new_alias->toname = new_alias->fromname + (to - from);
147 inserted = (void **) __tsearch (new_alias, &__gconv_alias_db,
148 __gconv_alias_compare);
149 if (inserted == NULL || *inserted != new_alias)
150 /* Something went wrong, free this entry. */
151 free (new_alias);
156 /* Add new alias. */
157 static void
158 add_alias (char *rp, void *modules)
160 /* We now expect two more string. The strings are normalized
161 (converted to UPPER case) and strored in the alias database. */
162 char *from, *to, *wp;
164 while (__isspace_l (*rp, _nl_C_locobj_ptr))
165 ++rp;
166 from = wp = rp;
167 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
168 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
169 if (*rp == '\0')
170 /* There is no `to' string on the line. Ignore it. */
171 return;
172 *wp++ = '\0';
173 to = ++rp;
174 while (__isspace_l (*rp, _nl_C_locobj_ptr))
175 ++rp;
176 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
177 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
178 if (to == wp)
179 /* No `to' string, ignore the line. */
180 return;
181 *wp++ = '\0';
183 add_alias2 (from, to, wp, modules);
187 /* Insert a data structure for a new module in the search tree. */
188 static void
189 internal_function
190 insert_module (struct gconv_module *newp, int tobefreed)
192 struct gconv_module **rootp = &__gconv_modules_db;
194 while (*rootp != NULL)
196 struct gconv_module *root = *rootp;
197 int cmpres;
199 cmpres = strcmp (newp->from_string, root->from_string);
200 if (cmpres == 0)
202 /* Both strings are identical. Insert the string at the
203 end of the `same' list if it is not already there. */
204 while (strcmp (newp->from_string, root->from_string) != 0
205 || strcmp (newp->to_string, root->to_string) != 0)
207 rootp = &root->same;
208 root = *rootp;
209 if (root == NULL)
210 break;
213 if (root != NULL)
215 /* This is a no new conversion. But maybe the cost is
216 better. */
217 if (newp->cost_hi < root->cost_hi
218 || (newp->cost_hi == root->cost_hi
219 && newp->cost_lo < root->cost_lo))
221 newp->left = root->left;
222 newp->right = root->right;
223 newp->same = root->same;
224 *rootp = newp;
226 free (root);
228 else if (tobefreed)
229 free (newp);
230 return;
233 break;
235 else if (cmpres < 0)
236 rootp = &root->left;
237 else
238 rootp = &root->right;
241 /* Plug in the new node here. */
242 *rootp = newp;
246 /* Add new module. */
247 static void
248 internal_function
249 add_module (char *rp, const char *directory, size_t dir_len, void **modules,
250 size_t *nmodules, int modcounter)
252 /* We expect now
253 1. `from' name
254 2. `to' name
255 3. filename of the module
256 4. an optional cost value
258 struct gconv_alias fake_alias;
259 struct gconv_module *new_module;
260 char *from, *to, *module, *wp;
261 int need_ext;
262 int cost_hi;
264 while (__isspace_l (*rp, _nl_C_locobj_ptr))
265 ++rp;
266 from = rp;
267 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
269 *rp = __toupper_l (*rp, _nl_C_locobj_ptr);
270 ++rp;
272 if (*rp == '\0')
273 return;
274 *rp++ = '\0';
275 to = wp = rp;
276 while (__isspace_l (*rp, _nl_C_locobj_ptr))
277 ++rp;
278 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
279 *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr);
280 if (*rp == '\0')
281 return;
282 *wp++ = '\0';
284 ++rp;
285 while (__isspace_l (*rp, _nl_C_locobj_ptr));
286 module = wp;
287 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
288 *wp++ = *rp++;
289 if (*rp == '\0')
291 /* There is no cost, use one by default. */
292 *wp++ = '\0';
293 cost_hi = 1;
295 else
297 /* There might be a cost value. */
298 char *endp;
300 *wp++ = '\0';
301 cost_hi = strtol (rp, &endp, 10);
302 if (rp == endp || cost_hi < 1)
303 /* No useful information. */
304 cost_hi = 1;
307 if (module[0] == '\0')
308 /* No module name given. */
309 return;
310 if (module[0] == '/')
311 dir_len = 0;
313 /* See whether we must add the ending. */
314 need_ext = 0;
315 if (wp - module < (ptrdiff_t) sizeof (gconv_module_ext)
316 || memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext,
317 sizeof (gconv_module_ext)) != 0)
318 /* We must add the module extension. */
319 need_ext = sizeof (gconv_module_ext) - 1;
321 /* See whether we have already an alias with this name defined. */
322 fake_alias.fromname = strndupa (from, to - from);
324 if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare) != NULL)
325 /* This module duplicates an alias. */
326 return;
328 new_module = (struct gconv_module *) calloc (1,
329 sizeof (struct gconv_module)
330 + (wp - from)
331 + dir_len + need_ext);
332 if (new_module != NULL)
334 char *tmp;
336 new_module->from_string = tmp = (char *) (new_module + 1);
337 tmp = __mempcpy (tmp, from, to - from);
339 new_module->to_string = tmp;
340 tmp = __mempcpy (tmp, to, module - to);
342 new_module->cost_hi = cost_hi;
343 new_module->cost_lo = modcounter;
345 new_module->module_name = tmp;
347 if (dir_len != 0)
348 tmp = __mempcpy (tmp, directory, dir_len);
350 tmp = __mempcpy (tmp, module, wp - module);
352 if (need_ext)
353 memcpy (tmp - 1, gconv_module_ext, sizeof (gconv_module_ext));
355 /* Now insert the new module data structure in our search tree. */
356 insert_module (new_module, 1);
361 /* Read the next configuration file. */
362 static void
363 internal_function
364 read_conf_file (const char *filename, const char *directory, size_t dir_len,
365 void **modules, size_t *nmodules)
367 /* Note the file is opened with cancellation in the I/O functions
368 disabled. */
369 FILE *fp = fopen (filename, "rc");
370 char *line = NULL;
371 size_t line_len = 0;
372 static int modcounter;
374 /* Don't complain if a file is not present or readable, simply silently
375 ignore it. */
376 if (fp == NULL)
377 return;
379 /* No threads reading from this stream. */
380 __fsetlocking (fp, FSETLOCKING_BYCALLER);
382 /* Process the known entries of the file. Comments start with `#' and
383 end with the end of the line. Empty lines are ignored. */
384 while (!feof_unlocked (fp))
386 char *rp, *endp, *word;
387 ssize_t n = __getdelim (&line, &line_len, '\n', fp);
388 if (n < 0)
389 /* An error occurred. */
390 break;
392 rp = line;
393 /* Terminate the line (excluding comments or newline) by an NUL byte
394 to simplify the following code. */
395 endp = strchr (rp, '#');
396 if (endp != NULL)
397 *endp = '\0';
398 else
399 if (rp[n - 1] == '\n')
400 rp[n - 1] = '\0';
402 while (__isspace_l (*rp, _nl_C_locobj_ptr))
403 ++rp;
405 /* If this is an empty line go on with the next one. */
406 if (rp == endp)
407 continue;
409 word = rp;
410 while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr))
411 ++rp;
413 if (rp - word == sizeof ("alias") - 1
414 && memcmp (word, "alias", sizeof ("alias") - 1) == 0)
415 add_alias (rp, *modules);
416 else if (rp - word == sizeof ("module") - 1
417 && memcmp (word, "module", sizeof ("module") - 1) == 0)
418 add_module (rp, directory, dir_len, modules, nmodules, modcounter++);
419 /* else */
420 /* Otherwise ignore the line. */
423 free (line);
425 fclose (fp);
429 /* Determine the directories we are looking for data in. */
430 void
431 internal_function
432 __gconv_get_path (void)
434 struct path_elem *result;
435 __libc_lock_define_initialized (static, lock);
437 __libc_lock_lock (lock);
439 /* Make sure there wasn't a second thread doing it already. */
440 result = (struct path_elem *) __gconv_path_elem;
441 if (result == NULL)
443 /* Determine the complete path first. */
444 char *gconv_path;
445 size_t gconv_path_len;
446 char *elem;
447 char *oldp;
448 char *cp;
449 int nelems;
450 char *cwd;
451 size_t cwdlen;
453 if (__gconv_path_envvar == NULL)
455 /* No user-defined path. Make a modifiable copy of the
456 default path. */
457 gconv_path = strdupa (default_gconv_path);
458 gconv_path_len = sizeof (default_gconv_path);
459 cwd = NULL;
460 cwdlen = 0;
462 else
464 /* Append the default path to the user-defined path. */
465 size_t user_len = strlen (__gconv_path_envvar);
467 gconv_path_len = user_len + 1 + sizeof (default_gconv_path);
468 gconv_path = alloca (gconv_path_len);
469 __mempcpy (__mempcpy (__mempcpy (gconv_path, __gconv_path_envvar,
470 user_len),
471 ":", 1),
472 default_gconv_path, sizeof (default_gconv_path));
473 cwd = __getcwd (NULL, 0);
474 cwdlen = strlen (cwd);
476 assert (default_gconv_path[0] == '/');
478 /* In a first pass we calculate the number of elements. */
479 oldp = NULL;
480 cp = strchr (gconv_path, ':');
481 nelems = 1;
482 while (cp != NULL)
484 if (cp != oldp + 1)
485 ++nelems;
486 oldp = cp;
487 cp = strchr (cp + 1, ':');
490 /* Allocate the memory for the result. */
491 result = (struct path_elem *) malloc ((nelems + 1)
492 * sizeof (struct path_elem)
493 + gconv_path_len + nelems
494 + (nelems - 1) * (cwdlen + 1));
495 if (result != NULL)
497 char *strspace = (char *) &result[nelems + 1];
498 int n = 0;
500 /* Separate the individual parts. */
501 __gconv_max_path_elem_len = 0;
502 elem = __strtok_r (gconv_path, ":", &gconv_path);
503 assert (elem != NULL);
506 result[n].name = strspace;
507 if (elem[0] != '/')
509 assert (cwd != NULL);
510 strspace = __mempcpy (strspace, cwd, cwdlen);
511 *strspace++ = '/';
513 strspace = __stpcpy (strspace, elem);
514 if (strspace[-1] != '/')
515 *strspace++ = '/';
517 result[n].len = strspace - result[n].name;
518 if (result[n].len > __gconv_max_path_elem_len)
519 __gconv_max_path_elem_len = result[n].len;
521 *strspace++ = '\0';
522 ++n;
524 while ((elem = __strtok_r (NULL, ":", &gconv_path)) != NULL);
526 result[n].name = NULL;
527 result[n].len = 0;
530 __gconv_path_elem = result ?: (struct path_elem *) &empty_path_elem;
532 free (cwd);
535 __libc_lock_unlock (lock);
539 /* Read all configuration files found in the user-specified and the default
540 path. */
541 void
542 attribute_hidden
543 __gconv_read_conf (void)
545 void *modules = NULL;
546 size_t nmodules = 0;
547 int save_errno = errno;
548 size_t cnt;
550 /* First see whether we should use the cache. */
551 if (__gconv_load_cache () == 0)
553 /* Yes, we are done. */
554 __set_errno (save_errno);
555 return;
558 #ifndef STATIC_GCONV
559 /* Find out where we have to look. */
560 if (__gconv_path_elem == NULL)
561 __gconv_get_path ();
563 for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt)
565 const char *elem = __gconv_path_elem[cnt].name;
566 size_t elem_len = __gconv_path_elem[cnt].len;
567 char *filename;
569 /* No slash needs to be inserted between elem and gconv_conf_filename;
570 elem already ends in a slash. */
571 filename = alloca (elem_len + sizeof (gconv_conf_filename));
572 __mempcpy (__mempcpy (filename, elem, elem_len),
573 gconv_conf_filename, sizeof (gconv_conf_filename));
575 /* Read the next configuration file. */
576 read_conf_file (filename, elem, elem_len, &modules, &nmodules);
578 #endif
580 /* Add the internal modules. */
581 for (cnt = 0; cnt < sizeof (builtin_modules) / sizeof (builtin_modules[0]);
582 ++cnt)
584 struct gconv_alias fake_alias;
586 fake_alias.fromname = (char *) builtin_modules[cnt].from_string;
588 if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare)
589 != NULL)
590 /* It'll conflict so don't add it. */
591 continue;
593 insert_module (&builtin_modules[cnt], 0);
596 /* Add aliases for builtin conversions. */
597 const char *cp = builtin_aliases;
600 const char *from = cp;
601 const char *to = __rawmemchr (from, '\0') + 1;
602 cp = __rawmemchr (to, '\0') + 1;
604 add_alias2 (from, to, cp, modules);
606 while (*cp != '\0');
608 /* Restore the error number. */
609 __set_errno (save_errno);
614 /* Free all resources if necessary. */
615 libc_freeres_fn (free_mem)
617 if (__gconv_path_elem != NULL && __gconv_path_elem != &empty_path_elem)
618 free ((void *) __gconv_path_elem);