xref: /freebsd/lib/libc/iconv/citrus_iconv.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
1 /* $FreeBSD$ */
2 /* $NetBSD: citrus_iconv.c,v 1.7 2008/07/25 14:05:25 christos Exp $ */
3 
4 /*-
5  * Copyright (c)2003 Citrus Project,
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
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 (!issetugid() && getenv(CI_ENV_MAX_REUSE))
83 			shared_max_reuse = atoi(getenv(CI_ENV_MAX_REUSE));
84 		if (shared_max_reuse < 0)
85 			shared_max_reuse = CI_INITIAL_MAX_REUSE;
86 		isinit = true;
87 	}
88 	UNLOCK(&ci_lock);
89 }
90 
91 static __inline void
92 close_shared(struct _citrus_iconv_shared *ci)
93 {
94 
95 	if (ci) {
96 		if (ci->ci_module) {
97 			if (ci->ci_ops) {
98 				if (ci->ci_closure)
99 					(*ci->ci_ops->io_uninit_shared)(ci);
100 				free(ci->ci_ops);
101 			}
102 			_citrus_unload_module(ci->ci_module);
103 		}
104 		free(ci);
105 	}
106 }
107 
108 static __inline int
109 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
110     const char * __restrict convname, const char * __restrict src,
111     const char * __restrict dst)
112 {
113 	struct _citrus_iconv_shared *ci;
114 	_citrus_iconv_getops_t getops;
115 	const char *module;
116 	size_t len_convname;
117 	int ret;
118 
119 #ifdef INCOMPATIBLE_WITH_GNU_ICONV
120 	/*
121 	 * Sadly, the gnu tools expect iconv to actually parse the
122 	 * byte stream and don't allow for a pass-through when
123 	 * the (src,dest) encodings are the same.
124 	 * See gettext-0.18.3+ NEWS:
125 	 *   msgfmt now checks PO file headers more strictly with less
126 	 *   false-positives.
127 	 * NetBSD don't do this either.
128 	 */
129 	module = (strcmp(src, dst) != 0) ? "iconv_std" : "iconv_none";
130 #else
131 	module = "iconv_std";
132 #endif
133 
134 	/* initialize iconv handle */
135 	len_convname = strlen(convname);
136 	ci = malloc(sizeof(*ci) + len_convname + 1);
137 	if (!ci) {
138 		ret = errno;
139 		goto err;
140 	}
141 	ci->ci_module = NULL;
142 	ci->ci_ops = NULL;
143 	ci->ci_closure = NULL;
144 	ci->ci_convname = (void *)&ci[1];
145 	memcpy(ci->ci_convname, convname, len_convname + 1);
146 
147 	/* load module */
148 	ret = _citrus_load_module(&ci->ci_module, module);
149 	if (ret)
150 		goto err;
151 
152 	/* get operators */
153 	getops = (_citrus_iconv_getops_t)_citrus_find_getops(ci->ci_module,
154 	    module, "iconv");
155 	if (!getops) {
156 		ret = EOPNOTSUPP;
157 		goto err;
158 	}
159 	ci->ci_ops = malloc(sizeof(*ci->ci_ops));
160 	if (!ci->ci_ops) {
161 		ret = errno;
162 		goto err;
163 	}
164 	ret = (*getops)(ci->ci_ops);
165 	if (ret)
166 		goto err;
167 
168 	if (ci->ci_ops->io_init_shared == NULL ||
169 	    ci->ci_ops->io_uninit_shared == NULL ||
170 	    ci->ci_ops->io_init_context == NULL ||
171 	    ci->ci_ops->io_uninit_context == NULL ||
172 	    ci->ci_ops->io_convert == NULL)
173 		goto err;
174 
175 	/* initialize the converter */
176 	ret = (*ci->ci_ops->io_init_shared)(ci, src, dst);
177 	if (ret)
178 		goto err;
179 
180 	*rci = ci;
181 
182 	return (0);
183 err:
184 	close_shared(ci);
185 	return (ret);
186 }
187 
188 static __inline int
189 hash_func(const char *key)
190 {
191 
192 	return (_string_hash_func(key, CI_HASH_SIZE));
193 }
194 
195 static __inline int
196 match_func(struct _citrus_iconv_shared * __restrict ci,
197     const char * __restrict key)
198 {
199 
200 	return (strcmp(ci->ci_convname, key));
201 }
202 
203 static int
204 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
205     const char *src, const char *dst)
206 {
207 	struct _citrus_iconv_shared * ci;
208 	char convname[PATH_MAX];
209 	int hashval, ret = 0;
210 
211 	snprintf(convname, sizeof(convname), "%s/%s", src, dst);
212 
213 	WLOCK(&ci_lock);
214 
215 	/* lookup alread existing entry */
216 	hashval = hash_func(convname);
217 	_CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
218 	    convname, hashval);
219 	if (ci != NULL) {
220 		/* found */
221 		if (ci->ci_used_count == 0) {
222 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
223 			shared_num_unused--;
224 		}
225 		ci->ci_used_count++;
226 		*rci = ci;
227 		goto quit;
228 	}
229 
230 	/* create new entry */
231 	ret = open_shared(&ci, convname, src, dst);
232 	if (ret)
233 		goto quit;
234 
235 	_CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
236 	ci->ci_used_count = 1;
237 	*rci = ci;
238 
239 quit:
240 	UNLOCK(&ci_lock);
241 
242 	return (ret);
243 }
244 
245 static void
246 release_shared(struct _citrus_iconv_shared * __restrict ci)
247 {
248 
249 	WLOCK(&ci_lock);
250 	ci->ci_used_count--;
251 	if (ci->ci_used_count == 0) {
252 		/* put it into unused list */
253 		shared_num_unused++;
254 		TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
255 		/* flood out */
256 		while (shared_num_unused > shared_max_reuse) {
257 			ci = TAILQ_FIRST(&shared_unused);
258 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
259 			_CITRUS_HASH_REMOVE(ci, ci_hash_entry);
260 			shared_num_unused--;
261 			close_shared(ci);
262 		}
263 	}
264 
265 	UNLOCK(&ci_lock);
266 }
267 
268 /*
269  * _citrus_iconv_open:
270  *	open a converter for the specified in/out codes.
271  */
272 int
273 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
274     const char * __restrict src, const char * __restrict dst)
275 {
276 	struct _citrus_iconv *cv = NULL;
277 	struct _citrus_iconv_shared *ci = NULL;
278 	char realdst[PATH_MAX], realsrc[PATH_MAX];
279 	char buf[PATH_MAX], path[PATH_MAX];
280 	int ret;
281 
282 	init_cache();
283 
284 	/* GNU behaviour, using locale encoding if "" or "char" is specified */
285 	if ((strcmp(src, "") == 0) || (strcmp(src, "char") == 0))
286 		src = nl_langinfo(CODESET);
287 	if ((strcmp(dst, "") == 0) || (strcmp(dst, "char") == 0))
288 		dst = nl_langinfo(CODESET);
289 
290 	/* resolve codeset name aliases */
291 	strlcpy(realsrc, _lookup_alias(path, src, buf, (size_t)PATH_MAX,
292 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
293 	strlcpy(realdst, _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
294 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
295 
296 	/* sanity check */
297 	if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
298 		return (EINVAL);
299 
300 	/* get shared record */
301 	ret = get_shared(&ci, realsrc, realdst);
302 	if (ret)
303 		return (ret);
304 
305 	/* create/init context */
306 	if (*rcv == NULL) {
307 		cv = malloc(sizeof(*cv));
308 		if (cv == NULL) {
309 			ret = errno;
310 			release_shared(ci);
311 			return (ret);
312 		}
313 		*rcv = cv;
314 	}
315 	(*rcv)->cv_shared = ci;
316 	ret = (*ci->ci_ops->io_init_context)(*rcv);
317 	if (ret) {
318 		release_shared(ci);
319 		free(cv);
320 		return (ret);
321 	}
322 	return (0);
323 }
324 
325 /*
326  * _citrus_iconv_close:
327  *	close the specified converter.
328  */
329 void
330 _citrus_iconv_close(struct _citrus_iconv *cv)
331 {
332 
333 	if (cv) {
334 		(*cv->cv_shared->ci_ops->io_uninit_context)(cv);
335 		release_shared(cv->cv_shared);
336 		free(cv);
337 	}
338 }
339 
340 const char
341 *_citrus_iconv_canonicalize(const char *name)
342 {
343 	char *buf;
344 
345 	if ((buf = malloc((size_t)PATH_MAX)) == NULL)
346 		return (NULL);
347 	memset((void *)buf, 0, (size_t)PATH_MAX);
348 	_citrus_esdb_alias(name, buf, (size_t)PATH_MAX);
349 	return (buf);
350 }
351