1 | /* Cache handling for iconv modules. |
2 | Copyright (C) 2001-2017 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 2001. |
5 | |
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. |
10 | |
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. |
15 | |
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/>. */ |
19 | |
20 | #include <dlfcn.h> |
21 | #include <errno.h> |
22 | #include <fcntl.h> |
23 | #include <stdlib.h> |
24 | #include <string.h> |
25 | #include <unistd.h> |
26 | #include <sys/mman.h> |
27 | #include <sys/stat.h> |
28 | |
29 | #include <gconv_int.h> |
30 | #include <iconvconfig.h> |
31 | #include <not-cancel.h> |
32 | |
33 | #include "../intl/hash-string.h" |
34 | |
35 | static void *gconv_cache; |
36 | static size_t cache_size; |
37 | static int cache_malloced; |
38 | |
39 | |
40 | void * |
41 | __gconv_get_cache (void) |
42 | { |
43 | return gconv_cache; |
44 | } |
45 | |
46 | |
47 | int |
48 | internal_function |
49 | __gconv_load_cache (void) |
50 | { |
51 | int fd; |
52 | struct stat64 st; |
53 | struct gconvcache_header *; |
54 | |
55 | /* We cannot use the cache if the GCONV_PATH environment variable is |
56 | set. */ |
57 | __gconv_path_envvar = getenv ("GCONV_PATH" ); |
58 | if (__gconv_path_envvar != NULL) |
59 | return -1; |
60 | |
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) |
64 | /* Not available. */ |
65 | return -1; |
66 | |
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)) |
72 | { |
73 | close_and_exit: |
74 | close_not_cancel_no_status (fd); |
75 | return -1; |
76 | } |
77 | |
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)) |
83 | #endif |
84 | { |
85 | size_t already_read; |
86 | |
87 | gconv_cache = malloc (cache_size); |
88 | if (gconv_cache == NULL) |
89 | goto close_and_exit; |
90 | |
91 | already_read = 0; |
92 | do |
93 | { |
94 | ssize_t n = __read (fd, (char *) gconv_cache + already_read, |
95 | cache_size - already_read); |
96 | if (__builtin_expect (n, 0) == -1) |
97 | { |
98 | free (gconv_cache); |
99 | gconv_cache = NULL; |
100 | goto close_and_exit; |
101 | } |
102 | |
103 | already_read += n; |
104 | } |
105 | while (already_read < cache_size); |
106 | |
107 | cache_malloced = 1; |
108 | } |
109 | |
110 | /* We don't need the file descriptor anymore. */ |
111 | close_not_cancel_no_status (fd); |
112 | |
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)) |
121 | > cache_size, 0) |
122 | || __builtin_expect (header->module_offset >= cache_size, 0) |
123 | || __builtin_expect (header->otherconv_offset > cache_size, 0)) |
124 | { |
125 | if (cache_malloced) |
126 | { |
127 | free (gconv_cache); |
128 | cache_malloced = 0; |
129 | } |
130 | #ifdef _POSIX_MAPPED_FILES |
131 | else |
132 | __munmap (gconv_cache, cache_size); |
133 | #endif |
134 | gconv_cache = NULL; |
135 | |
136 | return -1; |
137 | } |
138 | |
139 | /* That worked. */ |
140 | return 0; |
141 | } |
142 | |
143 | |
144 | static int |
145 | internal_function |
146 | find_module_idx (const char *str, size_t *idxp) |
147 | { |
148 | unsigned int idx; |
149 | unsigned int hval; |
150 | unsigned int hval2; |
151 | const struct gconvcache_header *; |
152 | const char *strtab; |
153 | const struct hash_entry *hashtab; |
154 | unsigned int limit; |
155 | |
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); |
160 | |
161 | hval = __hash_string (str); |
162 | idx = hval % header->hash_size; |
163 | hval2 = 1 + hval % (header->hash_size - 2); |
164 | |
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) |
169 | { |
170 | *idxp = hashtab[idx].module_idx; |
171 | return 0; |
172 | } |
173 | else |
174 | if ((idx += hval2) >= header->hash_size) |
175 | idx -= header->hash_size; |
176 | |
177 | /* Nothing found. */ |
178 | return -1; |
179 | } |
180 | |
181 | |
182 | #ifndef STATIC_GCONV |
183 | static int |
184 | internal_function |
185 | find_module (const char *directory, const char *filename, |
186 | struct __gconv_step *result) |
187 | { |
188 | size_t dirlen = strlen (directory); |
189 | size_t fnamelen = strlen (filename) + 1; |
190 | char fullname[dirlen + fnamelen]; |
191 | int status = __GCONV_NOCONV; |
192 | |
193 | memcpy (__mempcpy (fullname, directory, dirlen), filename, fnamelen); |
194 | |
195 | result->__shlib_handle = __gconv_find_shlib (fullname); |
196 | if (result->__shlib_handle != NULL) |
197 | { |
198 | status = __GCONV_OK; |
199 | |
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; |
204 | |
205 | /* These settings can be overridden by the init function. */ |
206 | result->__btowc_fct = NULL; |
207 | result->__data = NULL; |
208 | |
209 | /* Call the init function. */ |
210 | if (result->__init_fct != NULL) |
211 | { |
212 | __gconv_init_fct init_fct = result->__init_fct; |
213 | #ifdef PTR_DEMANGLE |
214 | PTR_DEMANGLE (init_fct); |
215 | #endif |
216 | status = DL_CALL_FCT (init_fct, (result)); |
217 | |
218 | #ifdef PTR_MANGLE |
219 | if (result->__btowc_fct != NULL) |
220 | PTR_MANGLE (result->__btowc_fct); |
221 | #endif |
222 | } |
223 | } |
224 | |
225 | return status; |
226 | } |
227 | #endif |
228 | |
229 | |
230 | int |
231 | internal_function |
232 | __gconv_compare_alias_cache (const char *name1, const char *name2, int *result) |
233 | { |
234 | size_t name1_idx; |
235 | size_t name2_idx; |
236 | |
237 | if (gconv_cache == NULL) |
238 | return -1; |
239 | |
240 | if (find_module_idx (name1, &name1_idx) != 0 |
241 | || find_module_idx (name2, &name2_idx) != 0) |
242 | *result = strcmp (name1, name2); |
243 | else |
244 | *result = (int) (name1_idx - name2_idx); |
245 | |
246 | return 0; |
247 | } |
248 | |
249 | |
250 | int |
251 | internal_function |
252 | __gconv_lookup_cache (const char *toset, const char *fromset, |
253 | struct __gconv_step **handle, size_t *nsteps, int flags) |
254 | { |
255 | const struct gconvcache_header *; |
256 | const char *strtab; |
257 | size_t fromidx; |
258 | size_t toidx; |
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; |
263 | |
264 | if (gconv_cache == NULL) |
265 | /* We have no cache available. */ |
266 | return __GCONV_NODB; |
267 | |
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); |
272 | |
273 | if (find_module_idx (fromset, &fromidx) != 0 |
274 | || (header->module_offset + (fromidx + 1) * sizeof (struct module_entry) |
275 | > cache_size)) |
276 | return __GCONV_NOCONV; |
277 | from_module = &modtab[fromidx]; |
278 | |
279 | if (find_module_idx (toset, &toidx) != 0 |
280 | || (header->module_offset + (toidx + 1) * sizeof (struct module_entry) |
281 | > cache_size)) |
282 | return __GCONV_NOCONV; |
283 | to_module = &modtab[toidx]; |
284 | |
285 | /* Avoid copy-only transformations if the user requests. */ |
286 | if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) && fromidx == toidx) |
287 | return __GCONV_NULCONV; |
288 | |
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) |
292 | { |
293 | /* Search through the list to see whether there is a module |
294 | matching the destination character set. */ |
295 | const struct extra_entry *; |
296 | |
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) |
306 | + (extra->module_cnt |
307 | * sizeof (struct extra_entry_module))); |
308 | |
309 | if (extra->module_cnt != 0) |
310 | { |
311 | /* Use the extra module. First determine how many steps. */ |
312 | char *fromname; |
313 | int idx; |
314 | |
315 | *nsteps = extra->module_cnt; |
316 | *handle = result = |
317 | (struct __gconv_step *) malloc (extra->module_cnt |
318 | * sizeof (struct __gconv_step)); |
319 | if (result == NULL) |
320 | return __GCONV_NOMEM; |
321 | |
322 | fromname = (char *) strtab + from_module->canonname_offset; |
323 | idx = 0; |
324 | do |
325 | { |
326 | result[idx].__from_name = fromname; |
327 | fromname = result[idx].__to_name = |
328 | (char *) strtab + modtab[extra->module[idx].outname_offset].canonname_offset; |
329 | |
330 | result[idx].__counter = 1; |
331 | result[idx].__data = NULL; |
332 | |
333 | #ifndef STATIC_GCONV |
334 | if (strtab[extra->module[idx].dir_offset] != '\0') |
335 | { |
336 | /* Load the module, return handle for it. */ |
337 | int res; |
338 | |
339 | res = find_module (strtab + extra->module[idx].dir_offset, |
340 | strtab + extra->module[idx].name_offset, |
341 | &result[idx]); |
342 | if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK) |
343 | { |
344 | /* Something went wrong. */ |
345 | free (result); |
346 | goto try_internal; |
347 | } |
348 | } |
349 | else |
350 | #endif |
351 | /* It's a builtin transformation. */ |
352 | __gconv_get_builtin_trans (strtab |
353 | + extra->module[idx].name_offset, |
354 | &result[idx]); |
355 | |
356 | } |
357 | while (++idx < extra->module_cnt); |
358 | |
359 | return __GCONV_OK; |
360 | } |
361 | } |
362 | |
363 | try_internal: |
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; |
370 | |
371 | /* We will use up to two modules. Always allocate room for two. */ |
372 | result = (struct __gconv_step *) malloc (2 * sizeof (struct __gconv_step)); |
373 | if (result == NULL) |
374 | return __GCONV_NOMEM; |
375 | |
376 | *handle = result; |
377 | *nsteps = 0; |
378 | |
379 | /* Generate data structure for conversion to INTERNAL. */ |
380 | if (fromidx != 0) |
381 | { |
382 | result[0].__from_name = (char *) strtab + from_module->canonname_offset; |
383 | result[0].__to_name = (char *) "INTERNAL" ; |
384 | |
385 | result[0].__counter = 1; |
386 | result[0].__data = NULL; |
387 | |
388 | #ifndef STATIC_GCONV |
389 | if (strtab[from_module->todir_offset] != '\0') |
390 | { |
391 | /* Load the module, return handle for it. */ |
392 | int res = find_module (strtab + from_module->todir_offset, |
393 | strtab + from_module->toname_offset, |
394 | &result[0]); |
395 | if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK) |
396 | { |
397 | /* Something went wrong. */ |
398 | free (result); |
399 | return res; |
400 | } |
401 | } |
402 | else |
403 | #endif |
404 | /* It's a builtin transformation. */ |
405 | __gconv_get_builtin_trans (strtab + from_module->toname_offset, |
406 | &result[0]); |
407 | |
408 | ++*nsteps; |
409 | } |
410 | |
411 | /* Generate data structure for conversion from INTERNAL. */ |
412 | if (toidx != 0) |
413 | { |
414 | int idx = *nsteps; |
415 | |
416 | result[idx].__from_name = (char *) "INTERNAL" ; |
417 | result[idx].__to_name = (char *) strtab + to_module->canonname_offset; |
418 | |
419 | result[idx].__counter = 1; |
420 | result[idx].__data = NULL; |
421 | |
422 | #ifndef STATIC_GCONV |
423 | if (strtab[to_module->fromdir_offset] != '\0') |
424 | { |
425 | /* Load the module, return handle for it. */ |
426 | int res = find_module (strtab + to_module->fromdir_offset, |
427 | strtab + to_module->fromname_offset, |
428 | &result[idx]); |
429 | if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK) |
430 | { |
431 | /* Something went wrong. */ |
432 | if (idx != 0) |
433 | __gconv_release_step (&result[0]); |
434 | free (result); |
435 | return res; |
436 | } |
437 | } |
438 | else |
439 | #endif |
440 | /* It's a builtin transformation. */ |
441 | __gconv_get_builtin_trans (strtab + to_module->fromname_offset, |
442 | &result[idx]); |
443 | |
444 | ++*nsteps; |
445 | } |
446 | |
447 | return __GCONV_OK; |
448 | } |
449 | |
450 | |
451 | /* Free memory allocated for the transformation record. */ |
452 | void |
453 | internal_function |
454 | __gconv_release_cache (struct __gconv_step *steps, size_t nsteps) |
455 | { |
456 | if (gconv_cache != NULL) |
457 | /* The only thing we have to deallocate is the record with the |
458 | steps. */ |
459 | free (steps); |
460 | } |
461 | |
462 | |
463 | /* Free all resources if necessary. */ |
464 | libc_freeres_fn (free_mem) |
465 | { |
466 | if (cache_malloced) |
467 | free (gconv_cache); |
468 | #ifdef _POSIX_MAPPED_FILES |
469 | else if (gconv_cache != NULL) |
470 | __munmap (gconv_cache, cache_size); |
471 | #endif |
472 | } |
473 | |