xref: /freebsd/lib/libc/iconv/citrus_iconv.c (revision 7750ad47a9a7dbc83f87158464170c8640723293)
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 __inline void
72 init_cache(void)
73 {
74 
75 	WLOCK;
76 	if (!isinit) {
77 		_CITRUS_HASH_INIT(&shared_pool, CI_HASH_SIZE);
78 		TAILQ_INIT(&shared_unused);
79 		shared_max_reuse = -1;
80 		if (!issetugid() && getenv(CI_ENV_MAX_REUSE))
81 			shared_max_reuse = atoi(getenv(CI_ENV_MAX_REUSE));
82 		if (shared_max_reuse < 0)
83 			shared_max_reuse = CI_INITIAL_MAX_REUSE;
84 		isinit = true;
85 	}
86 	UNLOCK;
87 }
88 
89 static __inline void
90 close_shared(struct _citrus_iconv_shared *ci)
91 {
92 
93 	if (ci) {
94 		if (ci->ci_module) {
95 			if (ci->ci_ops) {
96 				if (ci->ci_closure)
97 					(*ci->ci_ops->io_uninit_shared)(ci);
98 				free(ci->ci_ops);
99 			}
100 			_citrus_unload_module(ci->ci_module);
101 		}
102 		free(ci);
103 	}
104 }
105 
106 static __inline int
107 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
108     const char * __restrict convname, const char * __restrict src,
109     const char * __restrict dst)
110 {
111 	struct _citrus_iconv_shared *ci;
112 	_citrus_iconv_getops_t getops;
113 	const char *module;
114 	size_t len_convname;
115 	int ret;
116 
117 	module = (strcmp(src, dst) != 0) ? "iconv_std" : "iconv_none";
118 
119 	/* initialize iconv handle */
120 	len_convname = strlen(convname);
121 	ci = malloc(sizeof(*ci) + len_convname + 1);
122 	if (!ci) {
123 		ret = errno;
124 		goto err;
125 	}
126 	ci->ci_module = NULL;
127 	ci->ci_ops = NULL;
128 	ci->ci_closure = NULL;
129 	ci->ci_convname = (void *)&ci[1];
130 	memcpy(ci->ci_convname, convname, len_convname + 1);
131 
132 	/* load module */
133 	ret = _citrus_load_module(&ci->ci_module, module);
134 	if (ret)
135 		goto err;
136 
137 	/* get operators */
138 	getops = (_citrus_iconv_getops_t)_citrus_find_getops(ci->ci_module,
139 	    module, "iconv");
140 	if (!getops) {
141 		ret = EOPNOTSUPP;
142 		goto err;
143 	}
144 	ci->ci_ops = malloc(sizeof(*ci->ci_ops));
145 	if (!ci->ci_ops) {
146 		ret = errno;
147 		goto err;
148 	}
149 	ret = (*getops)(ci->ci_ops);
150 	if (ret)
151 		goto err;
152 
153 	if (ci->ci_ops->io_init_shared == NULL ||
154 	    ci->ci_ops->io_uninit_shared == NULL ||
155 	    ci->ci_ops->io_init_context == NULL ||
156 	    ci->ci_ops->io_uninit_context == NULL ||
157 	    ci->ci_ops->io_convert == NULL)
158 		goto err;
159 
160 	/* initialize the converter */
161 	ret = (*ci->ci_ops->io_init_shared)(ci, src, dst);
162 	if (ret)
163 		goto err;
164 
165 	*rci = ci;
166 
167 	return (0);
168 err:
169 	close_shared(ci);
170 	return (ret);
171 }
172 
173 static __inline int
174 hash_func(const char *key)
175 {
176 
177 	return (_string_hash_func(key, CI_HASH_SIZE));
178 }
179 
180 static __inline int
181 match_func(struct _citrus_iconv_shared * __restrict ci,
182     const char * __restrict key)
183 {
184 
185 	return (strcmp(ci->ci_convname, key));
186 }
187 
188 static int
189 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
190     const char *src, const char *dst)
191 {
192 	struct _citrus_iconv_shared * ci;
193 	char convname[PATH_MAX];
194 	int hashval, ret = 0;
195 
196 	snprintf(convname, sizeof(convname), "%s/%s", src, dst);
197 
198 	WLOCK;
199 
200 	/* lookup alread existing entry */
201 	hashval = hash_func(convname);
202 	_CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
203 	    convname, hashval);
204 	if (ci != NULL) {
205 		/* found */
206 		if (ci->ci_used_count == 0) {
207 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
208 			shared_num_unused--;
209 		}
210 		ci->ci_used_count++;
211 		*rci = ci;
212 		goto quit;
213 	}
214 
215 	/* create new entry */
216 	ret = open_shared(&ci, convname, src, dst);
217 	if (ret)
218 		goto quit;
219 
220 	_CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
221 	ci->ci_used_count = 1;
222 	*rci = ci;
223 
224 quit:
225 	UNLOCK;
226 
227 	return (ret);
228 }
229 
230 static void
231 release_shared(struct _citrus_iconv_shared * __restrict ci)
232 {
233 
234 	WLOCK;
235 	ci->ci_used_count--;
236 	if (ci->ci_used_count == 0) {
237 		/* put it into unused list */
238 		shared_num_unused++;
239 		TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
240 		/* flood out */
241 		while (shared_num_unused > shared_max_reuse) {
242 			ci = TAILQ_FIRST(&shared_unused);
243 			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
244 			_CITRUS_HASH_REMOVE(ci, ci_hash_entry);
245 			shared_num_unused--;
246 			close_shared(ci);
247 		}
248 	}
249 
250 	UNLOCK;
251 }
252 
253 /*
254  * _citrus_iconv_open:
255  *	open a converter for the specified in/out codes.
256  */
257 int
258 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
259     const char * __restrict src, const char * __restrict dst)
260 {
261 	struct _citrus_iconv *cv;
262 	struct _citrus_iconv_shared *ci = NULL;
263 	char realdst[PATH_MAX], realsrc[PATH_MAX];
264 	char buf[PATH_MAX], path[PATH_MAX];
265 	int ret;
266 
267 	init_cache();
268 
269 	/* GNU behaviour, using locale encoding if "" or "char" is specified */
270 	if ((strcmp(src, "") == 0) || (strcmp(src, "char") == 0))
271 		src = nl_langinfo(CODESET);
272 	if ((strcmp(dst, "") == 0) || (strcmp(dst, "char") == 0))
273 		dst = nl_langinfo(CODESET);
274 
275 	/* resolve codeset name aliases */
276 	strlcpy(realsrc, _lookup_alias(path, src, buf, (size_t)PATH_MAX,
277 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
278 	strlcpy(realdst, _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
279 	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
280 
281 	/* sanity check */
282 	if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
283 		return (EINVAL);
284 
285 	/* get shared record */
286 	ret = get_shared(&ci, realsrc, realdst);
287 	if (ret)
288 		return (ret);
289 
290 	/* create/init context */
291 	if (*rcv == NULL) {
292 		cv = malloc(sizeof(*cv));
293 		if (cv == NULL) {
294 			ret = errno;
295 			release_shared(ci);
296 			return (ret);
297 		}
298 		*rcv = cv;
299 	}
300 	(*rcv)->cv_shared = ci;
301 	ret = (*ci->ci_ops->io_init_context)(*rcv);
302 	if (ret) {
303 		release_shared(ci);
304 		free(*rcv);
305 		return (ret);
306 	}
307 	return (0);
308 }
309 
310 /*
311  * _citrus_iconv_close:
312  *	close the specified converter.
313  */
314 void
315 _citrus_iconv_close(struct _citrus_iconv *cv)
316 {
317 
318 	if (cv) {
319 		(*cv->cv_shared->ci_ops->io_uninit_context)(cv);
320 		release_shared(cv->cv_shared);
321 		free(cv);
322 	}
323 }
324 
325 const char
326 *_citrus_iconv_canonicalize(const char *name)
327 {
328 	char *buf;
329 
330 	if ((buf = malloc((size_t)PATH_MAX)) == NULL)
331 		return (NULL);
332 	memset((void *)buf, 0, (size_t)PATH_MAX);
333 	_citrus_esdb_alias(name, buf, (size_t)PATH_MAX);
334 	return (buf);
335 }
336