xref: /freebsd/lib/libc/iconv/citrus_mapper.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /* $FreeBSD$ */
2 /*	$NetBSD: citrus_mapper.c,v 1.10 2012/06/08 07:49:42 martin Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-2-Clause
6  *
7  * Copyright (c)2003 Citrus Project,
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <sys/queue.h>
36 
37 #include <assert.h>
38 #include <errno.h>
39 #include <limits.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "citrus_namespace.h"
45 #include "citrus_types.h"
46 #include "citrus_region.h"
47 #include "citrus_lock.h"
48 #include "citrus_memstream.h"
49 #include "citrus_bcs.h"
50 #include "citrus_mmap.h"
51 #include "citrus_module.h"
52 #include "citrus_hash.h"
53 #include "citrus_mapper.h"
54 
55 #define _CITRUS_MAPPER_DIR	"mapper.dir"
56 
57 #define CM_HASH_SIZE 101
58 #define REFCOUNT_PERSISTENT	-1
59 
60 static pthread_rwlock_t		cm_lock = PTHREAD_RWLOCK_INITIALIZER;
61 
62 struct _citrus_mapper_area {
63 	_CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE)	 ma_cache;
64 	char							*ma_dir;
65 };
66 
67 /*
68  * _citrus_mapper_create_area:
69  *	create mapper area
70  */
71 
72 int
73 _citrus_mapper_create_area(
74     struct _citrus_mapper_area *__restrict *__restrict rma,
75     const char *__restrict area)
76 {
77 	struct _citrus_mapper_area *ma;
78 	struct stat st;
79 	char path[PATH_MAX];
80 	int ret;
81 
82 	WLOCK(&cm_lock);
83 
84 	if (*rma != NULL) {
85 		ret = 0;
86 		goto quit;
87 	}
88 
89 	snprintf(path, (size_t)PATH_MAX, "%s/%s", area, _CITRUS_MAPPER_DIR);
90 
91 	ret = stat(path, &st);
92 	if (ret)
93 		goto quit;
94 
95 	ma = malloc(sizeof(*ma));
96 	if (ma == NULL) {
97 		ret = errno;
98 		goto quit;
99 	}
100 	ma->ma_dir = strdup(area);
101 	if (ma->ma_dir == NULL) {
102 		ret = errno;
103 		free(ma);
104 		goto quit;
105 	}
106 	_CITRUS_HASH_INIT(&ma->ma_cache, CM_HASH_SIZE);
107 
108 	*rma = ma;
109 	ret = 0;
110 quit:
111 	UNLOCK(&cm_lock);
112 
113 	return (ret);
114 }
115 
116 
117 /*
118  * lookup_mapper_entry:
119  *	lookup mapper.dir entry in the specified directory.
120  *
121  * line format of iconv.dir file:
122  *	mapper	module	arg
123  * mapper : mapper name.
124  * module : mapper module name.
125  * arg    : argument for the module (generally, description file name)
126  */
127 
128 static int
129 lookup_mapper_entry(const char *dir, const char *mapname, void *linebuf,
130     size_t linebufsize, const char **module, const char **variable)
131 {
132 	struct _region r;
133 	struct _memstream ms;
134 	const char *cp, *cq;
135 	char *p;
136 	char path[PATH_MAX];
137 	size_t len;
138 	int ret;
139 
140 	/* create mapper.dir path */
141 	snprintf(path, (size_t)PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
142 
143 	/* open read stream */
144 	ret = _map_file(&r, path);
145 	if (ret)
146 		return (ret);
147 
148 	_memstream_bind(&ms, &r);
149 
150 	/* search the line matching to the map name */
151 	cp = _memstream_matchline(&ms, mapname, &len, 0);
152 	if (!cp) {
153 		ret = ENOENT;
154 		goto quit;
155 	}
156 	if (!len || len > linebufsize - 1) {
157 		ret = EINVAL;
158 		goto quit;
159 	}
160 
161 	p = linebuf;
162 	/* get module name */
163 	*module = p;
164 	cq = _bcs_skip_nonws_len(cp, &len);
165 	strlcpy(p, cp, (size_t)(cq - cp + 1));
166 	p += cq - cp + 1;
167 
168 	/* get variable */
169 	*variable = p;
170 	cp = _bcs_skip_ws_len(cq, &len);
171 	strlcpy(p, cp, len + 1);
172 
173 	ret = 0;
174 
175 quit:
176 	_unmap_file(&r);
177 	return (ret);
178 }
179 
180 /*
181  * mapper_close:
182  *	simply close a mapper. (without handling hash)
183  */
184 static void
185 mapper_close(struct _citrus_mapper *cm)
186 {
187 	if (cm->cm_module) {
188 		if (cm->cm_ops) {
189 			if (cm->cm_closure)
190 				(*cm->cm_ops->mo_uninit)(cm);
191 			free(cm->cm_ops);
192 		}
193 		_citrus_unload_module(cm->cm_module);
194 	}
195 	free(cm->cm_traits);
196 	free(cm);
197 }
198 
199 /*
200  * mapper_open:
201  *	simply open a mapper. (without handling hash)
202  */
203 static int
204 mapper_open(struct _citrus_mapper_area *__restrict ma,
205     struct _citrus_mapper * __restrict * __restrict rcm,
206     const char * __restrict module,
207     const char * __restrict variable)
208 {
209 	struct _citrus_mapper *cm;
210 	_citrus_mapper_getops_t getops;
211 	int ret;
212 
213 	/* initialize mapper handle */
214 	cm = malloc(sizeof(*cm));
215 	if (!cm)
216 		return (errno);
217 
218 	cm->cm_module = NULL;
219 	cm->cm_ops = NULL;
220 	cm->cm_closure = NULL;
221 	cm->cm_traits = NULL;
222 	cm->cm_refcount = 0;
223 	cm->cm_key = NULL;
224 
225 	/* load module */
226 	ret = _citrus_load_module(&cm->cm_module, module);
227 	if (ret)
228 		goto err;
229 
230 	/* get operators */
231 	getops = (_citrus_mapper_getops_t)
232 	    _citrus_find_getops(cm->cm_module, module, "mapper");
233 	if (!getops) {
234 		ret = EOPNOTSUPP;
235 		goto err;
236 	}
237 	cm->cm_ops = malloc(sizeof(*cm->cm_ops));
238 	if (!cm->cm_ops) {
239 		ret = errno;
240 		goto err;
241 	}
242 	ret = (*getops)(cm->cm_ops);
243 	if (ret)
244 		goto err;
245 
246 	if (!cm->cm_ops->mo_init ||
247 	    !cm->cm_ops->mo_uninit ||
248 	    !cm->cm_ops->mo_convert ||
249 	    !cm->cm_ops->mo_init_state) {
250 		ret = EINVAL;
251 		goto err;
252 	}
253 
254 	/* allocate traits structure */
255 	cm->cm_traits = malloc(sizeof(*cm->cm_traits));
256 	if (cm->cm_traits == NULL) {
257 		ret = errno;
258 		goto err;
259 	}
260 	/* initialize the mapper */
261 	ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
262 	    (const void *)variable, strlen(variable) + 1,
263 	    cm->cm_traits, sizeof(*cm->cm_traits));
264 	if (ret)
265 		goto err;
266 
267 	*rcm = cm;
268 
269 	return (0);
270 
271 err:
272 	mapper_close(cm);
273 	return (ret);
274 }
275 
276 /*
277  * _citrus_mapper_open_direct:
278  *	open a mapper.
279  */
280 int
281 _citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
282     struct _citrus_mapper * __restrict * __restrict rcm,
283     const char * __restrict module, const char * __restrict variable)
284 {
285 
286 	return (mapper_open(ma, rcm, module, variable));
287 }
288 
289 /*
290  * hash_func
291  */
292 static __inline int
293 hash_func(const char *key)
294 {
295 
296 	return (_string_hash_func(key, CM_HASH_SIZE));
297 }
298 
299 /*
300  * match_func
301  */
302 static __inline int
303 match_func(struct _citrus_mapper *cm, const char *key)
304 {
305 
306 	return (strcmp(cm->cm_key, key));
307 }
308 
309 /*
310  * _citrus_mapper_open:
311  *	open a mapper with looking up "mapper.dir".
312  */
313 int
314 _citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
315     struct _citrus_mapper * __restrict * __restrict rcm,
316     const char * __restrict mapname)
317 {
318 	struct _citrus_mapper *cm;
319 	char linebuf[PATH_MAX];
320 	const char *module, *variable;
321 	int hashval, ret;
322 
323 	variable = NULL;
324 
325 	WLOCK(&cm_lock);
326 
327 	/* search in the cache */
328 	hashval = hash_func(mapname);
329 	_CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
330 	    hashval);
331 	if (cm) {
332 		/* found */
333 		cm->cm_refcount++;
334 		*rcm = cm;
335 		ret = 0;
336 		goto quit;
337 	}
338 
339 	/* search mapper entry */
340 	ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf,
341 	    (size_t)PATH_MAX, &module, &variable);
342 	if (ret)
343 		goto quit;
344 
345 	/* open mapper */
346 	UNLOCK(&cm_lock);
347 	ret = mapper_open(ma, &cm, module, variable);
348 	WLOCK(&cm_lock);
349 	if (ret)
350 		goto quit;
351 	cm->cm_key = strdup(mapname);
352 	if (cm->cm_key == NULL) {
353 		ret = errno;
354 		_mapper_close(cm);
355 		goto quit;
356 	}
357 
358 	/* insert to the cache */
359 	cm->cm_refcount = 1;
360 	_CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
361 
362 	*rcm = cm;
363 	ret = 0;
364 quit:
365 	UNLOCK(&cm_lock);
366 
367 	return (ret);
368 }
369 
370 /*
371  * _citrus_mapper_close:
372  *	close the specified mapper.
373  */
374 void
375 _citrus_mapper_close(struct _citrus_mapper *cm)
376 {
377 
378 	if (cm) {
379 		WLOCK(&cm_lock);
380 		if (cm->cm_refcount == REFCOUNT_PERSISTENT)
381 			goto quit;
382 		if (cm->cm_refcount > 0) {
383 			if (--cm->cm_refcount > 0)
384 				goto quit;
385 			_CITRUS_HASH_REMOVE(cm, cm_entry);
386 			free(cm->cm_key);
387 		}
388 		UNLOCK(&cm_lock);
389 		mapper_close(cm);
390 		return;
391 quit:
392 		UNLOCK(&cm_lock);
393 	}
394 }
395 
396 /*
397  * _citrus_mapper_set_persistent:
398  *	set persistent count.
399  */
400 void
401 _citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
402 {
403 
404 	WLOCK(&cm_lock);
405 	cm->cm_refcount = REFCOUNT_PERSISTENT;
406 	UNLOCK(&cm_lock);
407 }
408