xref: /freebsd/lib/libc/iconv/citrus_mapper.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
1 /* $FreeBSD$ */
2 /* $NetBSD: citrus_mapper.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/stat.h>
33 #include <sys/queue.h>
34 
35 #include <assert.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 
42 #include "citrus_namespace.h"
43 #include "citrus_types.h"
44 #include "citrus_region.h"
45 #include "citrus_lock.h"
46 #include "citrus_memstream.h"
47 #include "citrus_bcs.h"
48 #include "citrus_mmap.h"
49 #include "citrus_module.h"
50 #include "citrus_hash.h"
51 #include "citrus_mapper.h"
52 
53 #define _CITRUS_MAPPER_DIR	"mapper.dir"
54 
55 #define CM_HASH_SIZE 101
56 #define REFCOUNT_PERSISTENT	-1
57 
58 struct _citrus_mapper_area {
59 	_CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE)	 ma_cache;
60 	char							*ma_dir;
61 };
62 
63 /*
64  * _citrus_mapper_create_area:
65  *	create mapper area
66  */
67 
68 int
69 _citrus_mapper_create_area(
70     struct _citrus_mapper_area *__restrict *__restrict rma,
71     const char *__restrict area)
72 {
73 	struct _citrus_mapper_area *ma;
74 	struct stat st;
75 	char path[PATH_MAX];
76 	int ret;
77 
78 	WLOCK;
79 
80 	if (*rma != NULL) {
81 		ret = 0;
82 		goto quit;
83 	}
84 
85 	snprintf(path, (size_t)PATH_MAX, "%s/%s", area, _CITRUS_MAPPER_DIR);
86 
87 	ret = stat(path, &st);
88 	if (ret)
89 		goto quit;
90 
91 	ma = malloc(sizeof(*ma));
92 	if (ma == NULL) {
93 		ret = errno;
94 		goto quit;
95 	}
96 	ma->ma_dir = strdup(area);
97 	if (ma->ma_dir == NULL) {
98 		ret = errno;
99 		free(ma->ma_dir);
100 		goto quit;
101 	}
102 	_CITRUS_HASH_INIT(&ma->ma_cache, CM_HASH_SIZE);
103 
104 	*rma = ma;
105 	ret = 0;
106 quit:
107 	UNLOCK;
108 
109 	return (ret);
110 }
111 
112 
113 /*
114  * lookup_mapper_entry:
115  *	lookup mapper.dir entry in the specified directory.
116  *
117  * line format of iconv.dir file:
118  *	mapper	module	arg
119  * mapper : mapper name.
120  * module : mapper module name.
121  * arg    : argument for the module (generally, description file name)
122  */
123 
124 static int
125 lookup_mapper_entry(const char *dir, const char *mapname, void *linebuf,
126     size_t linebufsize, const char **module, const char **variable)
127 {
128 	struct _region r;
129 	struct _memstream ms;
130 	const char *cp, *cq;
131 	char *p;
132 	char path[PATH_MAX];
133 	size_t len;
134 	int ret;
135 
136 	/* create mapper.dir path */
137 	snprintf(path, (size_t)PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
138 
139 	/* open read stream */
140 	ret = _map_file(&r, path);
141 	if (ret)
142 		return (ret);
143 
144 	_memstream_bind(&ms, &r);
145 
146 	/* search the line matching to the map name */
147 	cp = _memstream_matchline(&ms, mapname, &len, 0);
148 	if (!cp) {
149 		ret = ENOENT;
150 		goto quit;
151 	}
152 	if (!len || len > linebufsize - 1) {
153 		ret = EINVAL;
154 		goto quit;
155 	}
156 
157 	p = linebuf;
158 	/* get module name */
159 	*module = p;
160 	cq = _bcs_skip_nonws_len(cp, &len);
161 	strlcpy(p, cp, (size_t)(cq - cp + 1));
162 	p += cq - cp + 1;
163 
164 	/* get variable */
165 	*variable = p;
166 	cp = _bcs_skip_ws_len(cq, &len);
167 	strlcpy(p, cp, len + 1);
168 
169 	ret = 0;
170 
171 quit:
172 	_unmap_file(&r);
173 	return (ret);
174 }
175 
176 /*
177  * mapper_close:
178  *	simply close a mapper. (without handling hash)
179  */
180 static void
181 mapper_close(struct _citrus_mapper *cm)
182 {
183 	if (cm->cm_module) {
184 		if (cm->cm_ops) {
185 			if (cm->cm_closure)
186 				(*cm->cm_ops->mo_uninit)(cm);
187 			free(cm->cm_ops);
188 		}
189 		_citrus_unload_module(cm->cm_module);
190 	}
191 	free(cm->cm_traits);
192 	free(cm);
193 }
194 
195 /*
196  * mapper_open:
197  *	simply open a mapper. (without handling hash)
198  */
199 static int
200 mapper_open(struct _citrus_mapper_area *__restrict ma,
201     struct _citrus_mapper * __restrict * __restrict rcm,
202     const char * __restrict module,
203     const char * __restrict variable)
204 {
205 	struct _citrus_mapper *cm;
206 	_citrus_mapper_getops_t getops;
207 	int ret;
208 
209 	/* initialize mapper handle */
210 	cm = malloc(sizeof(*cm));
211 	if (!cm)
212 		return (errno);
213 
214 	cm->cm_module = NULL;
215 	cm->cm_ops = NULL;
216 	cm->cm_closure = NULL;
217 	cm->cm_traits = NULL;
218 	cm->cm_refcount = 0;
219 	cm->cm_key = NULL;
220 
221 	/* load module */
222 	ret = _citrus_load_module(&cm->cm_module, module);
223 	if (ret)
224 		goto err;
225 
226 	/* get operators */
227 	getops = (_citrus_mapper_getops_t)
228 	    _citrus_find_getops(cm->cm_module, module, "mapper");
229 	if (!getops) {
230 		ret = EOPNOTSUPP;
231 		goto err;
232 	}
233 	cm->cm_ops = malloc(sizeof(*cm->cm_ops));
234 	if (!cm->cm_ops) {
235 		ret = errno;
236 		goto err;
237 	}
238 	ret = (*getops)(cm->cm_ops);
239 	if (ret)
240 		goto err;
241 
242 	if (!cm->cm_ops->mo_init ||
243 	    !cm->cm_ops->mo_uninit ||
244 	    !cm->cm_ops->mo_convert ||
245 	    !cm->cm_ops->mo_init_state)
246 		goto err;
247 
248 	/* allocate traits structure */
249 	cm->cm_traits = malloc(sizeof(*cm->cm_traits));
250 	if (cm->cm_traits == NULL) {
251 		ret = errno;
252 		goto err;
253 	}
254 	/* initialize the mapper */
255 	ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
256 	    (const void *)variable, strlen(variable) + 1,
257 	    cm->cm_traits, sizeof(*cm->cm_traits));
258 	if (ret)
259 		goto err;
260 
261 	*rcm = cm;
262 
263 	return (0);
264 
265 err:
266 	mapper_close(cm);
267 	return (ret);
268 }
269 
270 /*
271  * _citrus_mapper_open_direct:
272  *	open a mapper.
273  */
274 int
275 _citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
276     struct _citrus_mapper * __restrict * __restrict rcm,
277     const char * __restrict module, const char * __restrict variable)
278 {
279 
280 	return (mapper_open(ma, rcm, module, variable));
281 }
282 
283 /*
284  * hash_func
285  */
286 static __inline int
287 hash_func(const char *key)
288 {
289 
290 	return (_string_hash_func(key, CM_HASH_SIZE));
291 }
292 
293 /*
294  * match_func
295  */
296 static __inline int
297 match_func(struct _citrus_mapper *cm, const char *key)
298 {
299 
300 	return (strcmp(cm->cm_key, key));
301 }
302 
303 /*
304  * _citrus_mapper_open:
305  *	open a mapper with looking up "mapper.dir".
306  */
307 int
308 _citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
309     struct _citrus_mapper * __restrict * __restrict rcm,
310     const char * __restrict mapname)
311 {
312 	struct _citrus_mapper *cm;
313 	char linebuf[PATH_MAX];
314 	const char *module, *variable;
315 	int hashval, ret;
316 
317 	variable = NULL;
318 
319 	WLOCK;
320 
321 	/* search in the cache */
322 	hashval = hash_func(mapname);
323 	_CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
324 	    hashval);
325 	if (cm) {
326 		/* found */
327 		cm->cm_refcount++;
328 		*rcm = cm;
329 		ret = 0;
330 		goto quit;
331 	}
332 
333 	/* search mapper entry */
334 	ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf,
335 	    (size_t)PATH_MAX, &module, &variable);
336 	if (ret)
337 		goto quit;
338 
339 	/* open mapper */
340 	ret = mapper_open(ma, &cm, module, variable);
341 	if (ret)
342 		goto quit;
343 	cm->cm_key = strdup(mapname);
344 	if (cm->cm_key == NULL) {
345 		ret = errno;
346 		_mapper_close(cm);
347 		goto quit;
348 	}
349 
350 	/* insert to the cache */
351 	cm->cm_refcount = 1;
352 	_CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
353 
354 	*rcm = cm;
355 	ret = 0;
356 quit:
357 	UNLOCK;
358 
359 	return (ret);
360 }
361 
362 /*
363  * _citrus_mapper_close:
364  *	close the specified mapper.
365  */
366 void
367 _citrus_mapper_close(struct _citrus_mapper *cm)
368 {
369 
370 	if (cm) {
371 		WLOCK;
372 		if (cm->cm_refcount == REFCOUNT_PERSISTENT)
373 			goto quit;
374 		if (cm->cm_refcount > 0) {
375 			if (--cm->cm_refcount > 0)
376 				goto quit;
377 			_CITRUS_HASH_REMOVE(cm, cm_entry);
378 			free(cm->cm_key);
379 		}
380 		mapper_close(cm);
381 quit:
382 		UNLOCK;
383 	}
384 }
385 
386 /*
387  * _citrus_mapper_set_persistent:
388  *	set persistent count.
389  */
390 void
391 _citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
392 {
393 
394 	WLOCK;
395 	cm->cm_refcount = REFCOUNT_PERSISTENT;
396 	UNLOCK;
397 }
398