1 /* $NetBSD: citrus_iconv.c,v 1.11 2019/10/09 23:24:00 christos Exp $ */
2
3 /*-
4 * Copyright (c)2003 Citrus Project,
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #if defined(LIBC_SCCS) && !defined(lint)
31 __RCSID("$NetBSD: citrus_iconv.c,v 1.11 2019/10/09 23:24:00 christos Exp $");
32 #endif /* LIBC_SCCS and not lint */
33
34 #include "namespace.h"
35 #include "reentrant.h"
36
37 #include <sys/types.h>
38 #include <sys/queue.h>
39
40 #include <assert.h>
41 #include <dirent.h>
42 #include <errno.h>
43 #include <limits.h>
44 #include <paths.h>
45 #include <stdbool.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50
51 #include "citrus_namespace.h"
52 #include "citrus_bcs.h"
53 #include "citrus_region.h"
54 #include "citrus_memstream.h"
55 #include "citrus_mmap.h"
56 #include "citrus_module.h"
57 #include "citrus_lookup.h"
58 #include "citrus_hash.h"
59 #include "citrus_iconv.h"
60
61 #define _CITRUS_ICONV_DIR "iconv.dir"
62 #define _CITRUS_ICONV_ALIAS "iconv.alias"
63
64 #define CI_HASH_SIZE 101
65 #define CI_INITIAL_MAX_REUSE 5
66 #define CI_ENV_MAX_REUSE "ICONV_MAX_REUSE"
67
68 #ifdef _REENTRANT
69 static rwlock_t lock = RWLOCK_INITIALIZER;
70 #endif
71
72 static bool isinit = false;
73 static _CITRUS_HASH_HEAD(, _citrus_iconv_shared, CI_HASH_SIZE) shared_pool;
74 static TAILQ_HEAD(, _citrus_iconv_shared) shared_unused;
75 static int shared_num_unused, shared_max_reuse;
76
77 static __inline void
init_cache(void)78 init_cache(void)
79 {
80 rwlock_wrlock(&lock);
81 if (!isinit) {
82 _CITRUS_HASH_INIT(&shared_pool, CI_HASH_SIZE);
83 TAILQ_INIT(&shared_unused);
84 shared_max_reuse = -1;
85 if (!issetugid() && getenv(CI_ENV_MAX_REUSE))
86 shared_max_reuse = atoi(getenv(CI_ENV_MAX_REUSE));
87 if (shared_max_reuse < 0)
88 shared_max_reuse = CI_INITIAL_MAX_REUSE;
89 isinit = true;
90 }
91 rwlock_unlock(&lock);
92 }
93
94 /*
95 * lookup_iconv_entry:
96 * lookup iconv.dir entry in the specified directory.
97 *
98 * line format of iconv.dir file:
99 * key module arg
100 * key : lookup key.
101 * module : iconv module name.
102 * arg : argument for the module (generally, description file name)
103 *
104 */
105 static __inline int
lookup_iconv_entry(const char * curdir,const char * key,char * linebuf,size_t linebufsize,const char ** module,const char ** variable)106 lookup_iconv_entry(const char *curdir, const char *key,
107 char *linebuf, size_t linebufsize,
108 const char **module, const char **variable)
109 {
110 const char *cp, *cq;
111 char *p, path[PATH_MAX];
112
113 /* iconv.dir path */
114 snprintf(path, (size_t)PATH_MAX, ("%s/" _CITRUS_ICONV_DIR), curdir);
115
116 /* lookup db */
117 cp = p = _lookup_simple(path, key, linebuf, linebufsize,
118 _LOOKUP_CASE_IGNORE);
119 if (p == NULL)
120 return ENOENT;
121
122 /* get module name */
123 *module = p;
124 cq = _bcs_skip_nonws(cp);
125 p[cq-cp] = '\0';
126 p += cq-cp+1;
127 cq++;
128
129 /* get variable */
130 cp = _bcs_skip_ws(cq);
131 *variable = p += cp - cq;
132 cq = _bcs_skip_nonws(cp);
133 p[cq-cp] = '\0';
134
135 return 0;
136 }
137
138 static __inline void
close_shared(struct _citrus_iconv_shared * ci)139 close_shared(struct _citrus_iconv_shared *ci)
140 {
141 if (ci) {
142 if (ci->ci_module) {
143 if (ci->ci_ops) {
144 if (ci->ci_closure)
145 (*ci->ci_ops->io_uninit_shared)(ci);
146 free(ci->ci_ops);
147 }
148 _citrus_unload_module(ci->ci_module);
149 }
150 free(ci);
151 }
152 }
153
154 static __inline int
open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,const char * __restrict basedir,const char * __restrict convname,const char * __restrict src,const char * __restrict dst)155 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
156 const char * __restrict basedir, const char * __restrict convname,
157 const char * __restrict src, const char * __restrict dst)
158 {
159 int ret;
160 struct _citrus_iconv_shared *ci;
161 _citrus_iconv_getops_t getops;
162 char linebuf[LINE_MAX];
163 const char *module, *variable;
164 size_t len_convname;
165
166 /* search converter entry */
167 ret = lookup_iconv_entry(basedir, convname, linebuf, sizeof(linebuf),
168 &module, &variable);
169 if (ret) {
170 if (ret == ENOENT)
171 /* fallback */
172 ret = lookup_iconv_entry(basedir, "*",
173 linebuf, sizeof(linebuf),
174 &module, &variable);
175 if (ret)
176 return ret;
177 }
178
179 /* initialize iconv handle */
180 len_convname = strlen(convname);
181 ci = malloc(sizeof(*ci)+len_convname+1);
182 if (!ci) {
183 ret = errno;
184 goto err;
185 }
186 ci->ci_module = NULL;
187 ci->ci_ops = NULL;
188 ci->ci_closure = NULL;
189 ci->ci_convname = (void *)&ci[1];
190 memcpy(ci->ci_convname, convname, len_convname+1);
191
192 /* load module */
193 ret = _citrus_load_module(&ci->ci_module, module);
194 if (ret)
195 goto err;
196
197 /* get operators */
198 getops = (_citrus_iconv_getops_t)
199 _citrus_find_getops(ci->ci_module, module, "iconv");
200 if (!getops) {
201 ret = EOPNOTSUPP;
202 goto err;
203 }
204 ci->ci_ops = malloc(sizeof(*ci->ci_ops));
205 if (!ci->ci_ops) {
206 ret = errno;
207 goto err;
208 }
209 ret = (*getops)(ci->ci_ops, sizeof(*ci->ci_ops),
210 _CITRUS_ICONV_ABI_VERSION);
211 if (ret)
212 goto err;
213
214 /* version check */
215 if (ci->ci_ops->io_abi_version == 1) {
216 /* binary compatibility broken at ver.2 */
217 ret = EINVAL;
218 goto err;
219 }
220
221 if (ci->ci_ops->io_init_shared == NULL ||
222 ci->ci_ops->io_uninit_shared == NULL ||
223 ci->ci_ops->io_init_context == NULL ||
224 ci->ci_ops->io_uninit_context == NULL ||
225 ci->ci_ops->io_convert == NULL) {
226 ret = EINVAL;
227 goto err;
228 }
229
230 /* initialize the converter */
231 ret = (*ci->ci_ops->io_init_shared)(ci, basedir, src, dst,
232 (const void *)variable,
233 strlen(variable)+1);
234 if (ret)
235 goto err;
236
237 *rci = ci;
238
239 return 0;
240 err:
241 close_shared(ci);
242 return ret;
243 }
244
245 static __inline int
hash_func(const char * key)246 hash_func(const char *key)
247 {
248 return _string_hash_func(key, CI_HASH_SIZE);
249 }
250
251 static __inline int
match_func(struct _citrus_iconv_shared * __restrict ci,const char * __restrict key)252 match_func(struct _citrus_iconv_shared * __restrict ci,
253 const char * __restrict key)
254 {
255 return strcmp(ci->ci_convname, key);
256 }
257
258 static int
get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,const char * basedir,const char * src,const char * dst)259 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
260 const char *basedir, const char *src, const char *dst)
261 {
262 int ret = 0;
263 int hashval;
264 struct _citrus_iconv_shared * ci;
265 char convname[2 * PATH_MAX];
266
267 snprintf(convname, sizeof(convname), "%s/%s", src, dst);
268
269 rwlock_wrlock(&lock);
270
271 /* lookup alread existing entry */
272 hashval = hash_func(convname);
273 _CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
274 convname, hashval);
275 if (ci != NULL) {
276 /* found */
277 if (ci->ci_used_count == 0) {
278 TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
279 shared_num_unused--;
280 }
281 ci->ci_used_count++;
282 *rci = ci;
283 goto quit;
284 }
285
286 /* create new entry */
287 ret = open_shared(&ci, basedir, convname, src, dst);
288 if (ret)
289 goto quit;
290
291 _CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
292 ci->ci_used_count = 1;
293 *rci = ci;
294
295 quit:
296 rwlock_unlock(&lock);
297
298 return ret;
299 }
300
301 static void
release_shared(struct _citrus_iconv_shared * __restrict ci)302 release_shared(struct _citrus_iconv_shared * __restrict ci)
303 {
304 rwlock_wrlock(&lock);
305
306 ci->ci_used_count--;
307 if (ci->ci_used_count == 0) {
308 /* put it into unused list */
309 shared_num_unused++;
310 TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
311 /* flood out */
312 while (shared_num_unused > shared_max_reuse) {
313 ci = TAILQ_FIRST(&shared_unused);
314 _DIAGASSERT(ci != NULL);
315 TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
316 _CITRUS_HASH_REMOVE(ci, ci_hash_entry);
317 shared_num_unused--;
318 close_shared(ci);
319 }
320 }
321
322 rwlock_unlock(&lock);
323 }
324
325 /*
326 * _citrus_iconv_open:
327 * open a converter for the specified in/out codes.
328 */
329 int
_citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,const char * __restrict basedir,const char * __restrict src,const char * __restrict dst)330 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
331 const char * __restrict basedir,
332 const char * __restrict src, const char * __restrict dst)
333 {
334 int ret;
335 struct _citrus_iconv_shared *ci = NULL;
336 struct _citrus_iconv *cv;
337 char realsrc[PATH_MAX], realdst[PATH_MAX];
338 char buf[PATH_MAX], path[PATH_MAX];
339
340 init_cache();
341
342 /* resolve codeset name aliases */
343 snprintf(path, sizeof(path), "%s/%s", basedir, _CITRUS_ICONV_ALIAS);
344 strlcpy(realsrc,
345 _lookup_alias(path, src, buf, (size_t)PATH_MAX,
346 _LOOKUP_CASE_IGNORE),
347 (size_t)PATH_MAX);
348 strlcpy(realdst,
349 _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
350 _LOOKUP_CASE_IGNORE),
351 (size_t)PATH_MAX);
352
353 /* sanity check */
354 if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
355 return EINVAL;
356
357 /* get shared record */
358 ret = get_shared(&ci, basedir, realsrc, realdst);
359 if (ret)
360 return ret;
361
362 /* create/init context */
363 cv = malloc(sizeof(*cv));
364 if (cv == NULL) {
365 ret = errno;
366 release_shared(ci);
367 return ret;
368 }
369 cv->cv_shared = ci;
370 ret = (*ci->ci_ops->io_init_context)(cv);
371 if (ret) {
372 release_shared(ci);
373 free(cv);
374 return ret;
375 }
376 *rcv = cv;
377
378 return 0;
379 }
380
381 /*
382 * _citrus_iconv_close:
383 * close the specified converter.
384 */
385 void
_citrus_iconv_close(struct _citrus_iconv * cv)386 _citrus_iconv_close(struct _citrus_iconv *cv)
387 {
388 if (cv) {
389 (*cv->cv_shared->ci_ops->io_uninit_context)(cv);
390 release_shared(cv->cv_shared);
391 free(cv);
392 }
393 }
394