citrus_iconv.c revision 331722 
1/* $FreeBSD: stable/11/lib/libc/iconv/citrus_iconv.c 331722 2018-03-29 02:50:57Z eadler $ */
2/*	$NetBSD: citrus_iconv.c,v 1.10 2011/11/19 18:34:21 tnozaki 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
66static bool			 isinit = false;
67static int			 shared_max_reuse, shared_num_unused;
68static _CITRUS_HASH_HEAD(, _citrus_iconv_shared, CI_HASH_SIZE) shared_pool;
69static TAILQ_HEAD(, _citrus_iconv_shared) shared_unused;
70
71static pthread_rwlock_t		 ci_lock = PTHREAD_RWLOCK_INITIALIZER;
72
73static __inline void
74init_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
91static __inline void
92close_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
108static __inline int
109open_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		ret = EINVAL;
174		goto err;
175	}
176
177	/* initialize the converter */
178	ret = (*ci->ci_ops->io_init_shared)(ci, src, dst);
179	if (ret)
180		goto err;
181
182	*rci = ci;
183
184	return (0);
185err:
186	close_shared(ci);
187	return (ret);
188}
189
190static __inline int
191hash_func(const char *key)
192{
193
194	return (_string_hash_func(key, CI_HASH_SIZE));
195}
196
197static __inline int
198match_func(struct _citrus_iconv_shared * __restrict ci,
199    const char * __restrict key)
200{
201
202	return (strcmp(ci->ci_convname, key));
203}
204
205static int
206get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
207    const char *src, const char *dst)
208{
209	struct _citrus_iconv_shared * ci;
210	char convname[PATH_MAX];
211	int hashval, ret = 0;
212
213	snprintf(convname, sizeof(convname), "%s/%s", src, dst);
214
215	WLOCK(&ci_lock);
216
217	/* lookup alread existing entry */
218	hashval = hash_func(convname);
219	_CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
220	    convname, hashval);
221	if (ci != NULL) {
222		/* found */
223		if (ci->ci_used_count == 0) {
224			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
225			shared_num_unused--;
226		}
227		ci->ci_used_count++;
228		*rci = ci;
229		goto quit;
230	}
231
232	/* create new entry */
233	ret = open_shared(&ci, convname, src, dst);
234	if (ret)
235		goto quit;
236
237	_CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
238	ci->ci_used_count = 1;
239	*rci = ci;
240
241quit:
242	UNLOCK(&ci_lock);
243
244	return (ret);
245}
246
247static void
248release_shared(struct _citrus_iconv_shared * __restrict ci)
249{
250
251	WLOCK(&ci_lock);
252	ci->ci_used_count--;
253	if (ci->ci_used_count == 0) {
254		/* put it into unused list */
255		shared_num_unused++;
256		TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
257		/* flood out */
258		while (shared_num_unused > shared_max_reuse) {
259			ci = TAILQ_FIRST(&shared_unused);
260			TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
261			_CITRUS_HASH_REMOVE(ci, ci_hash_entry);
262			shared_num_unused--;
263			close_shared(ci);
264		}
265	}
266
267	UNLOCK(&ci_lock);
268}
269
270/*
271 * _citrus_iconv_open:
272 *	open a converter for the specified in/out codes.
273 */
274int
275_citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
276    const char * __restrict src, const char * __restrict dst)
277{
278	struct _citrus_iconv *cv = NULL;
279	struct _citrus_iconv_shared *ci = NULL;
280	char realdst[PATH_MAX], realsrc[PATH_MAX];
281#ifdef _PATH_ICONV
282	char buf[PATH_MAX], path[PATH_MAX];
283#endif
284	int ret;
285
286	init_cache();
287
288	/* GNU behaviour, using locale encoding if "" or "char" is specified */
289	if ((strcmp(src, "") == 0) || (strcmp(src, "char") == 0))
290		src = nl_langinfo(CODESET);
291	if ((strcmp(dst, "") == 0) || (strcmp(dst, "char") == 0))
292		dst = nl_langinfo(CODESET);
293
294	/* resolve codeset name aliases */
295#ifdef _PATH_ICONV
296	snprintf(path, sizeof(path), "%s/%s", _PATH_ICONV, _CITRUS_ICONV_ALIAS);
297	strlcpy(realsrc, _lookup_alias(path, src, buf, (size_t)PATH_MAX,
298	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
299	strlcpy(realdst, _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
300	    _LOOKUP_CASE_IGNORE), (size_t)PATH_MAX);
301#else
302	strlcpy(realsrc, src, (size_t)PATH_MAX);
303	strlcpy(realdst, dst, (size_t)PATH_MAX);
304#endif
305
306	/* sanity check */
307	if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
308		return (EINVAL);
309
310	/* get shared record */
311	ret = get_shared(&ci, realsrc, realdst);
312	if (ret)
313		return (ret);
314
315	/* create/init context */
316	if (*rcv == NULL) {
317		cv = malloc(sizeof(*cv));
318		if (cv == NULL) {
319			ret = errno;
320			release_shared(ci);
321			return (ret);
322		}
323		*rcv = cv;
324	}
325	(*rcv)->cv_shared = ci;
326	ret = (*ci->ci_ops->io_init_context)(*rcv);
327	if (ret) {
328		release_shared(ci);
329		free(cv);
330		return (ret);
331	}
332	return (0);
333}
334
335/*
336 * _citrus_iconv_close:
337 *	close the specified converter.
338 */
339void
340_citrus_iconv_close(struct _citrus_iconv *cv)
341{
342
343	if (cv) {
344		(*cv->cv_shared->ci_ops->io_uninit_context)(cv);
345		release_shared(cv->cv_shared);
346		free(cv);
347	}
348}
349
350const char
351*_citrus_iconv_canonicalize(const char *name)
352{
353	char *buf;
354
355	if ((buf = calloc((size_t)PATH_MAX, sizeof(*buf))) == NULL)
356		return (NULL);
357	_citrus_esdb_alias(name, buf, (size_t)PATH_MAX);
358	return (buf);
359}
360