1 /* Cache handling for iconv modules.
2 Copyright (C) 2001-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 2001.
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, see
18 <http://www.gnu.org/licenses/>. */
29 #include <gconv_int.h>
30 #include <iconvconfig.h>
31 #include <not-cancel.h>
33 #include "../intl/hash-string.h"
35 static void *gconv_cache;
36 static size_t cache_size;
37 static int cache_malloced;
41 __gconv_get_cache (void)
49 __gconv_load_cache (void)
53 struct gconvcache_header *header;
55 /* We cannot use the cache if the GCONV_PATH environment variable is
57 __gconv_path_envvar = getenv ("GCONV_PATH");
58 if (__gconv_path_envvar != NULL)
61 /* See whether the cache file exists. */
62 fd = open_not_cancel (GCONV_MODULES_CACHE, O_RDONLY, 0);
63 if (__builtin_expect (fd, 0) == -1)
67 /* Get information about the file. */
68 if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0) < 0
69 /* We do not have to start looking at the file if it cannot contain
70 at least the cache header. */
71 || (size_t) st.st_size < sizeof (struct gconvcache_header))
74 close_not_cancel_no_status (fd);
78 /* Make the file content available. */
79 cache_size = st.st_size;
80 #ifdef _POSIX_MAPPED_FILES
81 gconv_cache = __mmap (NULL, cache_size, PROT_READ, MAP_SHARED, fd, 0);
82 if (__glibc_unlikely (gconv_cache == MAP_FAILED))
87 gconv_cache = malloc (cache_size);
88 if (gconv_cache == NULL)
94 ssize_t n = __read (fd, (char *) gconv_cache + already_read,
95 cache_size - already_read);
96 if (__builtin_expect (n, 0) == -1)
105 while (already_read < cache_size);
110 /* We don't need the file descriptor anymore. */
111 close_not_cancel_no_status (fd);
113 /* Check the consistency. */
114 header = (struct gconvcache_header *) gconv_cache;
115 if (__builtin_expect (header->magic, GCONVCACHE_MAGIC) != GCONVCACHE_MAGIC
116 || __builtin_expect (header->string_offset >= cache_size, 0)
117 || __builtin_expect (header->hash_offset >= cache_size, 0)
118 || __builtin_expect (header->hash_size == 0, 0)
119 || __builtin_expect ((header->hash_offset
120 + header->hash_size * sizeof (struct hash_entry))
122 || __builtin_expect (header->module_offset >= cache_size, 0)
123 || __builtin_expect (header->otherconv_offset > cache_size, 0))
130 #ifdef _POSIX_MAPPED_FILES
132 __munmap (gconv_cache, cache_size);
146 find_module_idx (const char *str, size_t *idxp)
151 const struct gconvcache_header *header;
153 const struct hash_entry *hashtab;
156 header = (const struct gconvcache_header *) gconv_cache;
157 strtab = (char *) gconv_cache + header->string_offset;
158 hashtab = (struct hash_entry *) ((char *) gconv_cache
159 + header->hash_offset);
161 hval = __hash_string (str);
162 idx = hval % header->hash_size;
163 hval2 = 1 + hval % (header->hash_size - 2);
165 limit = cache_size - header->string_offset;
166 while (hashtab[idx].string_offset != 0)
167 if (hashtab[idx].string_offset < limit
168 && strcmp (str, strtab + hashtab[idx].string_offset) == 0)
170 *idxp = hashtab[idx].module_idx;
174 if ((idx += hval2) >= header->hash_size)
175 idx -= header->hash_size;
185 find_module (const char *directory, const char *filename,
186 struct __gconv_step *result)
188 size_t dirlen = strlen (directory);
189 size_t fnamelen = strlen (filename) + 1;
190 char fullname[dirlen + fnamelen];
191 int status = __GCONV_NOCONV;
193 memcpy (__mempcpy (fullname, directory, dirlen), filename, fnamelen);
195 result->__shlib_handle = __gconv_find_shlib (fullname);
196 if (result->__shlib_handle != NULL)
200 result->__modname = NULL;
201 result->__fct = result->__shlib_handle->fct;
202 result->__init_fct = result->__shlib_handle->init_fct;
203 result->__end_fct = result->__shlib_handle->end_fct;
205 /* These settings can be overridden by the init function. */
206 result->__btowc_fct = NULL;
207 result->__data = NULL;
209 /* Call the init function. */
210 if (result->__init_fct != NULL)
212 __gconv_init_fct init_fct = result->__init_fct;
214 PTR_DEMANGLE (init_fct);
216 status = DL_CALL_FCT (init_fct, (result));
219 if (result->__btowc_fct != NULL)
220 PTR_MANGLE (result->__btowc_fct);
232 __gconv_compare_alias_cache (const char *name1, const char *name2, int *result)
237 if (gconv_cache == NULL)
240 if (find_module_idx (name1, &name1_idx) != 0
241 || find_module_idx (name2, &name2_idx) != 0)
242 *result = strcmp (name1, name2);
244 *result = (int) (name1_idx - name2_idx);
252 __gconv_lookup_cache (const char *toset, const char *fromset,
253 struct __gconv_step **handle, size_t *nsteps, int flags)
255 const struct gconvcache_header *header;
259 const struct module_entry *modtab;
260 const struct module_entry *from_module;
261 const struct module_entry *to_module;
262 struct __gconv_step *result;
264 if (gconv_cache == NULL)
265 /* We have no cache available. */
268 header = (const struct gconvcache_header *) gconv_cache;
269 strtab = (char *) gconv_cache + header->string_offset;
270 modtab = (const struct module_entry *) ((char *) gconv_cache
271 + header->module_offset);
273 if (find_module_idx (fromset, &fromidx) != 0
274 || (header->module_offset + (fromidx + 1) * sizeof (struct module_entry)
276 return __GCONV_NOCONV;
277 from_module = &modtab[fromidx];
279 if (find_module_idx (toset, &toidx) != 0
280 || (header->module_offset + (toidx + 1) * sizeof (struct module_entry)
282 return __GCONV_NOCONV;
283 to_module = &modtab[toidx];
285 /* Avoid copy-only transformations if the user requests. */
286 if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) && fromidx == toidx)
287 return __GCONV_NULCONV;
289 /* If there are special conversions available examine them first. */
290 if (fromidx != 0 && toidx != 0
291 && __builtin_expect (from_module->extra_offset, 0) != 0)
293 /* Search through the list to see whether there is a module
294 matching the destination character set. */
295 const struct extra_entry *extra;
297 /* Note the -1. This is due to the offset added in iconvconfig.
298 See there for more explanations. */
299 extra = (const struct extra_entry *) ((char *) gconv_cache
300 + header->otherconv_offset
301 + from_module->extra_offset - 1);
302 while (extra->module_cnt != 0
303 && extra->module[extra->module_cnt - 1].outname_offset != toidx)
304 extra = (const struct extra_entry *) ((char *) extra
305 + sizeof (struct extra_entry)
307 * sizeof (struct extra_entry_module)));
309 if (extra->module_cnt != 0)
311 /* Use the extra module. First determine how many steps. */
315 *nsteps = extra->module_cnt;
317 (struct __gconv_step *) malloc (extra->module_cnt
318 * sizeof (struct __gconv_step));
320 return __GCONV_NOMEM;
322 fromname = (char *) strtab + from_module->canonname_offset;
326 result[idx].__from_name = fromname;
327 fromname = result[idx].__to_name =
328 (char *) strtab + modtab[extra->module[idx].outname_offset].canonname_offset;
330 result[idx].__counter = 1;
331 result[idx].__data = NULL;
334 if (strtab[extra->module[idx].dir_offset] != '\0')
336 /* Load the module, return handle for it. */
339 res = find_module (strtab + extra->module[idx].dir_offset,
340 strtab + extra->module[idx].name_offset,
342 if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
344 /* Something went wrong. */
351 /* It's a builtin transformation. */
352 __gconv_get_builtin_trans (strtab
353 + extra->module[idx].name_offset,
357 while (++idx < extra->module_cnt);
364 /* See whether we can convert via the INTERNAL charset. */
365 if ((fromidx != 0 && __builtin_expect (from_module->fromname_offset, 1) == 0)
366 || (toidx != 0 && __builtin_expect (to_module->toname_offset, 1) == 0)
367 || (fromidx == 0 && toidx == 0))
368 /* Not possible. Nothing we can do. */
369 return __GCONV_NOCONV;
371 /* We will use up to two modules. Always allocate room for two. */
372 result = (struct __gconv_step *) malloc (2 * sizeof (struct __gconv_step));
374 return __GCONV_NOMEM;
379 /* Generate data structure for conversion to INTERNAL. */
382 result[0].__from_name = (char *) strtab + from_module->canonname_offset;
383 result[0].__to_name = (char *) "INTERNAL";
385 result[0].__counter = 1;
386 result[0].__data = NULL;
389 if (strtab[from_module->todir_offset] != '\0')
391 /* Load the module, return handle for it. */
392 int res = find_module (strtab + from_module->todir_offset,
393 strtab + from_module->toname_offset,
395 if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
397 /* Something went wrong. */
404 /* It's a builtin transformation. */
405 __gconv_get_builtin_trans (strtab + from_module->toname_offset,
411 /* Generate data structure for conversion from INTERNAL. */
416 result[idx].__from_name = (char *) "INTERNAL";
417 result[idx].__to_name = (char *) strtab + to_module->canonname_offset;
419 result[idx].__counter = 1;
420 result[idx].__data = NULL;
423 if (strtab[to_module->fromdir_offset] != '\0')
425 /* Load the module, return handle for it. */
426 int res = find_module (strtab + to_module->fromdir_offset,
427 strtab + to_module->fromname_offset,
429 if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
431 /* Something went wrong. */
433 __gconv_release_step (&result[0]);
440 /* It's a builtin transformation. */
441 __gconv_get_builtin_trans (strtab + to_module->fromname_offset,
451 /* Free memory allocated for the transformation record. */
454 __gconv_release_cache (struct __gconv_step *steps, size_t nsteps)
456 if (gconv_cache != NULL)
457 /* The only thing we have to deallocate is the record with the
463 /* Free all resources if necessary. */
464 libc_freeres_fn (free_mem)
468 #ifdef _POSIX_MAPPED_FILES
469 else if (gconv_cache != NULL)
470 __munmap (gconv_cache, cache_size);