xref: /freebsd/lib/libc/iconv/citrus_iconv.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*	$NetBSD: citrus_iconv.c,v 1.10 2011/11/19 18:34:21 tnozaki Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c)2003 Citrus Project,
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/queue.h>
33 
34 #include <assert.h>
35 #include <dirent.h>
36 #include <errno.h>
37 #include <iconv.h>
38 #include <langinfo.h>
39 #include <limits.h>
40 #include <paths.h>
41 #include <stdbool.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "citrus_namespace.h"
48 #include "citrus_bcs.h"
49 #include "citrus_esdb.h"
50 #include "citrus_region.h"
51 #include "citrus_memstream.h"
52 #include "citrus_mmap.h"
53 #include "citrus_module.h"
54 #include "citrus_lock.h"
55 #include "citrus_lookup.h"
56 #include "citrus_hash.h"
57 #include "citrus_iconv.h"
58 
59 #define _CITRUS_ICONV_DIR	"iconv.dir"
60 #define _CITRUS_ICONV_ALIAS	"iconv.alias"
61 
62 #define CI_HASH_SIZE 101
63 #define CI_INITIAL_MAX_REUSE	5
64 #define CI_ENV_MAX_REUSE	"ICONV_MAX_REUSE"
65 
66 static bool			 isinit = false;
67 static int			 shared_max_reuse, shared_num_unused;
68 static _CITRUS_HASH_HEAD(, _citrus_iconv_shared, CI_HASH_SIZE) shared_pool;
69 static TAILQ_HEAD(, _citrus_iconv_shared) shared_unused;
70 
71 static pthread_rwlock_t		 ci_lock = PTHREAD_RWLOCK_INITIALIZER;
72 
73 static __inline void
74 init_cache(void)
75 {
76 
77 	WLOCK(&ci_lock);
78 	if (!isinit) {
79 		_CITRUS_HASH_INIT(&shared_pool, CI_HASH_SIZE);
80 		TAILQ_INIT(&shared_unused);
81 		shared_max_reuse = -1;
82 		if (secure_getenv(CI_ENV_MAX_REUSE) != NULL)
83 			shared_max_reuse =
84 			    atoi(secure_getenv(CI_ENV_MAX_REUSE));
85 		if (shared_max_reuse < 0)
86 			shared_max_reuse = CI_INITIAL_MAX_REUSE;
87 		isinit = true;
88 	}
89 	UNLOCK(&ci_lock);
90 }
91 
92 static __inline void
93 close_shared(struct _citrus_iconv_shared *ci)
94 {
95 
96 	if (ci) {
97 		if (ci->ci_module) {
98 			if (ci->ci_ops) {
99 				if (ci->ci_closure)
100 					(*ci->ci_ops->io_uninit_shared)(ci);
101 				free(ci->ci_ops);
102 			}
103 			_citrus_unload_module(ci->ci_module);
104 		}
105 		free(ci);
106 	}
107 }
108 
109 static __inline int
110 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
111     const char * __restrict convname, const char * __restrict src,
112     const char * __restrict dst)
113 {
114 	struct _citrus_iconv_shared *ci;
115 	_citrus_iconv_getops_t getops;
116 	const char *module;
117 	size_t len_convname;
118 	int ret;
119 
120 #ifdef INCOMPATIBLE_WITH_GNU_ICONV
121 	/*
122 	 * Sadly, the gnu tools expect iconv to actually parse the
123 	 * byte stream and don't allow for a pass-through when
124 	 * the (src,dest) encodings are the same.
125 	 * See gettext-0.18.3+ NEWS:
126 	 *   msgfmt now checks PO file headers more strictly with less
127 	 *   false-positives.
128 	 * NetBSD, also, doesn't do the below pass-through.
129 	 *
130 	 * Also note that this currently falls short if dst options have been
131 	 * specified. It may be the case that we want to ignore EILSEQ, in which
132 	 * case we should also select iconv_std anyways.  This trick, while
133 	 * clever, may not be worth it.
134 	 */
135 	module = (strcmp(src, dst) != 0) ? "iconv_std" : "iconv_none";
136 #else
137 	module = "iconv_std";
138 #endif
139 
140 	/* initialize iconv handle */
141 	len_convname = strlen(convname);
142 	ci = calloc(1, sizeof(*ci) + len_convname + 1);
143 	if (!ci) {
144 		ret = errno;
145 		goto err;
146 	}
147 	ci->ci_convname = (void *)&ci[1];
148 	memcpy(ci->ci_convname, convname, len_convname + 1);
149 
150 	/* load module */
151 	ret = _citrus_load_module(&ci->ci_module, module);
152 	if (ret)
153 		goto err;
154 
155 	/* get operators */
156 	getops = (_citrus_iconv_getops_t)_citrus_find_getops(ci->ci_module,
157 	    module, "iconv");
158 	if (!getops) {
159 		ret = EOPNOTSUPP;
160 		goto err;
161 	}
162 	ci->ci_ops = malloc(sizeof(*ci->ci_ops));
163 	if (!ci->ci_ops) {
164 		ret = errno;
165 		goto err;
166 	}
167 	ret = (*getops)(ci->ci_ops);
168 	if (ret)
169 		goto err;
170 
171 	if (ci->ci_ops->io_init_shared == NULL ||
172 	    ci->ci_ops->io_uninit_shared == NULL ||
173 	    ci->ci_ops->io_init_context == NULL ||
174 	    ci->ci_ops->io_uninit_context == NULL ||
175 	    ci->ci_ops->io_convert == NULL) {
176 		ret = EINVAL;
177 		goto err;
178 	}
179 
180 	/* initialize the converter */
181 	ret = (*ci->ci_ops->io_init_shared)(ci, src, dst);
182 	if (ret)
183 		goto err;
184 
185 	*rci = ci;
186 
187 	return (0);
188 err:
189 	close_shared(ci);
190 	return (ret);
191 }
192 
193 static __inline int
194 hash_func(const char *key)
195 {
196 
197 	return (_string_hash_func(key, CI_HASH_SIZE));
198 }
199 
200 static __inline int
201 match_func(struct _citrus_iconv_shared * __restrict ci,
202     const char * __restrict key)
203 {
204 
205 	return (strcmp(ci->ci_convname, key));
206 }
207 
208 static int
209 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
210     const char *src, const char *dst)
211 {
212 	struct _citrus_iconv_shared * ci;
213 	char convname[PATH_MAX];
214 	int hashval, ret = 0;
215 
216 	snprintf(convname, sizeof(convname), "%s/%s", src, dst);
217 
218 	WLOCK(&ci_lock);
219 
220 	/* lookup alread existing entry */
221 	hashval = hash_func(convname);
222 	_CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
223 	    convname, hashval);
224 	if (ci != NULL) {
225 		/* found */
226 		if (ci->ci_used_count == 0) {
227 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
228 			shared_num_unused--;
229 		}
230 		ci->ci_used_count++;
231 		*rci = ci;
232 		goto quit;
233 	}
234 
235 	/* create new entry */
236 	ret = open_shared(&ci, convname, src, dst);
237 	if (ret)
238 		goto quit;
239 
240 	_CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
241 	ci->ci_used_count = 1;
242 	*rci = ci;
243 
244 quit:
245 	UNLOCK(&ci_lock);
246 
247 	return (ret);
248 }
249 
250 static void
251 release_shared(struct _citrus_iconv_shared * __restrict ci)
252 {
253 
254 	WLOCK(&ci_lock);
255 	ci->ci_used_count--;
256 	if (ci->ci_used_count == 0) {
257 		/* put it into unused list */
258 		shared_num_unused++;
259 		TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
260 		/* flood out */
261 		while (shared_num_unused > shared_max_reuse) {
262 			ci = TAILQ_FIRST(&shared_unused);
263 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
264 			_CITRUS_HASH_REMOVE(ci, ci_hash_entry);
265 			shared_num_unused--;
266 			close_shared(ci);
267 		}
268 	}
269 
270 	UNLOCK(&ci_lock);
271 }
272 
273 /*
274  * _citrus_iconv_open:
275  *	open a converter for the specified in/out codes.
276  */
277 int
278 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
279     const char * __restrict src, const char * __restrict dst)
280 {
281 	struct _citrus_iconv *cv = NULL;
282 	struct _citrus_iconv_shared *ci = NULL;
283 	char realdst[PATH_MAX], realsrc[PATH_MAX], *slashes;
284 #ifdef _PATH_ICONV
285 	char buf[PATH_MAX], path[PATH_MAX];
286 #endif
287 	int ret;
288 
289 	init_cache();
290 
291 	/* GNU behaviour, using locale encoding if "" or "char" is specified */
292 	if ((strcmp(src, "") == 0) || (strcmp(src, "char") == 0))
293 		src = nl_langinfo(CODESET);
294 	if ((strcmp(dst, "") == 0) || (strcmp(dst, "char") == 0))
295 		dst = nl_langinfo(CODESET);
296 
297 	strlcpy(realsrc, src, (size_t)PATH_MAX);
298 	if ((slashes = strstr(realsrc, "//")) != NULL)
299 		*slashes = '\0';
300 	strlcpy(realdst, dst, (size_t)PATH_MAX);
301 	if ((slashes = strstr(realdst, "//")) != NULL)
302 		*slashes = '\0';
303 
304 	/* resolve codeset name aliases */
305 #ifdef _PATH_ICONV
306 	/*
307 	 * Note that the below reads from realsrc and realdst while it's
308 	 * repopulating (writing to) realsrc and realdst, but it's done so with
309 	 * a trip through `buf`.
310 	 */
311 	snprintf(path, sizeof(path), "%s/%s", _PATH_ICONV, _CITRUS_ICONV_ALIAS);
312 	strlcpy(realsrc, _lookup_alias(path, realsrc, buf, (size_t)PATH_MAX,
313 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
314 	strlcpy(realdst, _lookup_alias(path, realdst, buf, (size_t)PATH_MAX,
315 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
316 #endif
317 
318 	/* sanity check */
319 	if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
320 		return (EINVAL);
321 
322 	/* get shared record */
323 	ret = get_shared(&ci, realsrc, realdst);
324 	if (ret)
325 		return (ret);
326 
327 	/* create/init context */
328 	if (*rcv == NULL) {
329 		cv = malloc(sizeof(*cv));
330 		if (cv == NULL) {
331 			ret = errno;
332 			release_shared(ci);
333 			return (ret);
334 		}
335 		*rcv = cv;
336 	}
337 	(*rcv)->cv_shared = ci;
338 	ret = (*ci->ci_ops->io_init_context)(*rcv);
339 	if (ret) {
340 		release_shared(ci);
341 		free(cv);
342 		return (ret);
343 	}
344 	return (0);
345 }
346 
347 /*
348  * _citrus_iconv_close:
349  *	close the specified converter.
350  */
351 void
352 _citrus_iconv_close(struct _citrus_iconv *cv)
353 {
354 
355 	if (cv) {
356 		(*cv->cv_shared->ci_ops->io_uninit_context)(cv);
357 		release_shared(cv->cv_shared);
358 		free(cv);
359 	}
360 }
361 
362 const char
363 *_citrus_iconv_canonicalize(const char *name)
364 {
365 	char *buf;
366 
367 	if ((buf = calloc((size_t)PATH_MAX, sizeof(*buf))) == NULL)
368 		return (NULL);
369 	_citrus_esdb_alias(name, buf, (size_t)PATH_MAX);
370 	return (buf);
371 }
372