xref: /freebsd/lib/libc/iconv/citrus_csmapper.c (revision 2a63c3be158216222d89a073dcbd6a72ee4aab5a)
1 /*	$NetBSD: citrus_csmapper.c,v 1.11 2011/11/20 07:43:52 tnozaki Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c)2003 Citrus Project,
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include <sys/endian.h>
33 #include <sys/types.h>
34 #include <sys/queue.h>
35 
36 #include <assert.h>
37 #include <errno.h>
38 #include <limits.h>
39 #include <paths.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_bcs.h"
47 #include "citrus_region.h"
48 #include "citrus_lock.h"
49 #include "citrus_memstream.h"
50 #include "citrus_mmap.h"
51 #include "citrus_module.h"
52 #include "citrus_hash.h"
53 #include "citrus_mapper.h"
54 #include "citrus_csmapper.h"
55 #include "citrus_pivot_file.h"
56 #include "citrus_db.h"
57 #include "citrus_db_hash.h"
58 #include "citrus_lookup.h"
59 
60 static struct _citrus_mapper_area	*maparea = NULL;
61 
62 static pthread_rwlock_t			ma_lock = PTHREAD_RWLOCK_INITIALIZER;
63 
64 #define CS_ALIAS	_PATH_CSMAPPER "/charset.alias"
65 #define CS_PIVOT	_PATH_CSMAPPER "/charset.pivot"
66 
67 
68 /* ---------------------------------------------------------------------- */
69 
70 static int
71 get32(struct _region *r, uint32_t *rval)
72 {
73 
74 	if (_region_size(r) != 4)
75 		return (EFTYPE);
76 
77 	memcpy(rval, _region_head(r), (size_t)4);
78 	*rval = be32toh(*rval);
79 
80 	return (0);
81 }
82 
83 static int
84 open_subdb(struct _citrus_db **subdb, struct _citrus_db *db, const char *src)
85 {
86 	struct _region r;
87 	int ret;
88 
89 	ret = _db_lookup_by_s(db, src, &r, NULL);
90 	if (ret)
91 		return (ret);
92 	ret = _db_open(subdb, &r, _CITRUS_PIVOT_SUB_MAGIC, _db_hash_std, NULL);
93 	if (ret)
94 		return (ret);
95 
96 	return (0);
97 }
98 
99 
100 #define NO_SUCH_FILE	EOPNOTSUPP
101 static int
102 find_best_pivot_pvdb(const char *src, const char *dst, char *pivot,
103     size_t pvlen, unsigned long *rnorm)
104 {
105 	struct _citrus_db *db1, *db2, *db3;
106 	struct _region fr, r1, r2;
107 	char buf[LINE_MAX];
108 	uint32_t val32;
109 	unsigned long norm;
110 	int i, num, ret;
111 
112 	ret = _map_file(&fr, CS_PIVOT ".pvdb");
113 	if (ret) {
114 		if (ret == ENOENT)
115 			ret = NO_SUCH_FILE;
116 		return (ret);
117 	}
118 	ret = _db_open(&db1, &fr, _CITRUS_PIVOT_MAGIC, _db_hash_std, NULL);
119 	if (ret)
120 		goto quit1;
121 	ret = open_subdb(&db2, db1, src);
122 	if (ret)
123 		goto quit2;
124 
125 	num = _db_get_num_entries(db2);
126 	*rnorm = ULONG_MAX;
127 	for (i = 0; i < num; i++) {
128 		/* iterate each pivot */
129 		ret = _db_get_entry(db2, i, &r1, &r2);
130 		if (ret)
131 			goto quit3;
132 		/* r1:pivot name, r2:norm among src and pivot */
133 		ret = get32(&r2, &val32);
134 		if (ret)
135 			goto quit3;
136 		norm = val32;
137 		snprintf(buf, sizeof(buf), "%.*s",
138 			 (int)_region_size(&r1), (char *)_region_head(&r1));
139 		/* buf: pivot name */
140 		ret = open_subdb(&db3, db1, buf);
141 		if (ret)
142 			goto quit3;
143 		if (_db_lookup_by_s(db3, dst, &r2, NULL) != 0)
144 			/* don't break the loop, test all src/dst pairs. */
145 			goto quit4;
146 		/* r2: norm among pivot and dst */
147 		ret = get32(&r2, &val32);
148 		if (ret)
149 			goto quit4;
150 		norm += val32;
151 		/* judge minimum norm */
152 		if (norm < *rnorm) {
153 			*rnorm = norm;
154 			strlcpy(pivot, buf, pvlen);
155 		}
156 quit4:
157 		_db_close(db3);
158 		if (ret)
159 			goto quit3;
160 	}
161 quit3:
162 	_db_close(db2);
163 quit2:
164 	_db_close(db1);
165 quit1:
166 	_unmap_file(&fr);
167 	if (ret)
168 		return (ret);
169 
170 	if (*rnorm == ULONG_MAX)
171 		return (ENOENT);
172 
173 	return (0);
174 }
175 
176 /* ---------------------------------------------------------------------- */
177 
178 struct zone {
179 	const char *begin, *end;
180 };
181 
182 struct parse_arg {
183 	char dst[PATH_MAX];
184 	unsigned long norm;
185 };
186 
187 static int
188 parse_line(struct parse_arg *pa, struct _region *r)
189 {
190 	struct zone z1, z2;
191 	char buf[20];
192 	size_t len;
193 
194 	len = _region_size(r);
195 	z1.begin = _bcs_skip_ws_len(_region_head(r), &len);
196 	if (len == 0)
197 		return (EFTYPE);
198 	z1.end = _bcs_skip_nonws_len(z1.begin, &len);
199 	if (len == 0)
200 		return (EFTYPE);
201 	z2.begin = _bcs_skip_ws_len(z1.end, &len);
202 	if (len == 0)
203 		return (EFTYPE);
204 	z2.end = _bcs_skip_nonws_len(z2.begin, &len);
205 
206 	/* z1 : dst name, z2 : norm */
207 	snprintf(pa->dst, sizeof(pa->dst),
208 	    "%.*s", (int)(z1.end-z1.begin), z1.begin);
209 	snprintf(buf, sizeof(buf),
210 	    "%.*s", (int)(z2.end-z2.begin), z2.begin);
211 	pa->norm = _bcs_strtoul(buf, NULL, 0);
212 
213 	return (0);
214 }
215 
216 static int
217 find_dst(struct parse_arg *pasrc, const char *dst)
218 {
219 	struct _lookup *cl;
220 	struct parse_arg padst;
221 	struct _region data;
222 	int ret;
223 
224 	ret = _lookup_seq_open(&cl, CS_PIVOT, _LOOKUP_CASE_IGNORE);
225 	if (ret)
226 		return (ret);
227 
228 	ret = _lookup_seq_lookup(cl, pasrc->dst, &data);
229 	while (ret == 0) {
230 		ret = parse_line(&padst, &data);
231 		if (ret)
232 			break;
233 		if (strcmp(dst, padst.dst) == 0) {
234 			pasrc->norm += padst.norm;
235 			break;
236 		}
237 		ret = _lookup_seq_next(cl, NULL, &data);
238 	}
239 	_lookup_seq_close(cl);
240 
241 	return (ret);
242 }
243 
244 static int
245 find_best_pivot_lookup(const char *src, const char *dst, char *pivot,
246     size_t pvlen, unsigned long *rnorm)
247 {
248 	struct _lookup *cl;
249 	struct _region data;
250 	struct parse_arg pa;
251 	char pivot_min[PATH_MAX];
252 	unsigned long norm_min;
253 	int ret;
254 
255 	ret = _lookup_seq_open(&cl, CS_PIVOT, _LOOKUP_CASE_IGNORE);
256 	if (ret)
257 		return (ret);
258 
259 	norm_min = ULONG_MAX;
260 
261 	/* find pivot code */
262 	ret = _lookup_seq_lookup(cl, src, &data);
263 	while (ret == 0) {
264 		ret = parse_line(&pa, &data);
265 		if (ret)
266 			break;
267 		ret = find_dst(&pa, dst);
268 		if (ret)
269 			break;
270 		if (pa.norm < norm_min) {
271 			norm_min = pa.norm;
272 			strlcpy(pivot_min, pa.dst, sizeof(pivot_min));
273 		}
274 		ret = _lookup_seq_next(cl, NULL, &data);
275 	}
276 	_lookup_seq_close(cl);
277 
278 	if (ret != ENOENT)
279 		return (ret);
280 	if (norm_min == ULONG_MAX)
281 		return (ENOENT);
282 	strlcpy(pivot, pivot_min, pvlen);
283 	if (rnorm)
284 		*rnorm = norm_min;
285 
286 	return (0);
287 }
288 
289 static int
290 find_best_pivot(const char *src, const char *dst, char *pivot, size_t pvlen,
291     unsigned long *rnorm)
292 {
293 	int ret;
294 
295 	ret = find_best_pivot_pvdb(src, dst, pivot, pvlen, rnorm);
296 	if (ret == NO_SUCH_FILE)
297 		ret = find_best_pivot_lookup(src, dst, pivot, pvlen, rnorm);
298 
299 	return (ret);
300 }
301 
302 static __inline int
303 open_serial_mapper(struct _citrus_mapper_area *__restrict ma,
304     struct _citrus_mapper * __restrict * __restrict rcm,
305     const char *src, const char *pivot, const char *dst)
306 {
307 	char buf[PATH_MAX];
308 
309 	snprintf(buf, sizeof(buf), "%s/%s,%s/%s", src, pivot, pivot, dst);
310 
311 	return (_mapper_open_direct(ma, rcm, "mapper_serial", buf));
312 }
313 
314 static struct _citrus_csmapper *csm_none = NULL;
315 static int
316 get_none(struct _citrus_mapper_area *__restrict ma,
317     struct _citrus_csmapper *__restrict *__restrict rcsm)
318 {
319 	int ret;
320 
321 	WLOCK(&ma_lock);
322 	if (csm_none) {
323 		*rcsm = csm_none;
324 		ret = 0;
325 		goto quit;
326 	}
327 
328 	ret = _mapper_open_direct(ma, &csm_none, "mapper_none", "");
329 	if (ret)
330 		goto quit;
331 	_mapper_set_persistent(csm_none);
332 
333 	*rcsm = csm_none;
334 	ret = 0;
335 quit:
336 	UNLOCK(&ma_lock);
337 	return (ret);
338 }
339 
340 int
341 _citrus_csmapper_open(struct _citrus_csmapper * __restrict * __restrict rcsm,
342     const char * __restrict src, const char * __restrict dst, uint32_t flags,
343     unsigned long *rnorm)
344 {
345 	const char *realsrc, *realdst;
346 	char buf1[PATH_MAX], buf2[PATH_MAX], key[PATH_MAX], pivot[PATH_MAX];
347 	unsigned long norm;
348 	int ret;
349 
350 	norm = 0;
351 
352 	ret = _citrus_mapper_create_area(&maparea, _PATH_CSMAPPER);
353 	if (ret)
354 		return (ret);
355 
356 	realsrc = _lookup_alias(CS_ALIAS, src, buf1, sizeof(buf1),
357 	    _LOOKUP_CASE_IGNORE);
358 	realdst = _lookup_alias(CS_ALIAS, dst, buf2, sizeof(buf2),
359 	    _LOOKUP_CASE_IGNORE);
360 	if (!strcmp(realsrc, realdst)) {
361 		ret = get_none(maparea, rcsm);
362 		if (ret == 0 && rnorm != NULL)
363 			*rnorm = 0;
364 		return (ret);
365 	}
366 
367 	snprintf(key, sizeof(key), "%s/%s", realsrc, realdst);
368 
369 	ret = _mapper_open(maparea, rcsm, key);
370 	if (ret == 0) {
371 		if (rnorm != NULL)
372 			*rnorm = 0;
373 		return (0);
374 	}
375 	if (ret != ENOENT || (flags & _CSMAPPER_F_PREVENT_PIVOT)!=0)
376 		return (ret);
377 
378 	ret = find_best_pivot(realsrc, realdst, pivot, sizeof(pivot), &norm);
379 	if (ret)
380 		return (ret);
381 
382 	ret = open_serial_mapper(maparea, rcsm, realsrc, pivot, realdst);
383 	if (ret == 0 && rnorm != NULL)
384 		*rnorm = norm;
385 
386 	return (ret);
387 }
388