xref: /freebsd/lib/libc/iconv/citrus_csmapper.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /* $FreeBSD$ */
2 /*	$NetBSD: citrus_csmapper.c,v 1.11 2011/11/20 07:43:52 tnozaki 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/endian.h>
34 #include <sys/types.h>
35 #include <sys/queue.h>
36 
37 #include <assert.h>
38 #include <errno.h>
39 #include <limits.h>
40 #include <paths.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "citrus_namespace.h"
46 #include "citrus_types.h"
47 #include "citrus_bcs.h"
48 #include "citrus_region.h"
49 #include "citrus_lock.h"
50 #include "citrus_memstream.h"
51 #include "citrus_mmap.h"
52 #include "citrus_module.h"
53 #include "citrus_hash.h"
54 #include "citrus_mapper.h"
55 #include "citrus_csmapper.h"
56 #include "citrus_pivot_file.h"
57 #include "citrus_db.h"
58 #include "citrus_db_hash.h"
59 #include "citrus_lookup.h"
60 
61 static struct _citrus_mapper_area	*maparea = NULL;
62 
63 static pthread_rwlock_t			ma_lock = PTHREAD_RWLOCK_INITIALIZER;
64 
65 #define CS_ALIAS	_PATH_CSMAPPER "/charset.alias"
66 #define CS_PIVOT	_PATH_CSMAPPER "/charset.pivot"
67 
68 
69 /* ---------------------------------------------------------------------- */
70 
71 static int
72 get32(struct _region *r, uint32_t *rval)
73 {
74 
75 	if (_region_size(r) != 4)
76 		return (EFTYPE);
77 
78 	memcpy(rval, _region_head(r), (size_t)4);
79 	*rval = be32toh(*rval);
80 
81 	return (0);
82 }
83 
84 static int
85 open_subdb(struct _citrus_db **subdb, struct _citrus_db *db, const char *src)
86 {
87 	struct _region r;
88 	int ret;
89 
90 	ret = _db_lookup_by_s(db, src, &r, NULL);
91 	if (ret)
92 		return (ret);
93 	ret = _db_open(subdb, &r, _CITRUS_PIVOT_SUB_MAGIC, _db_hash_std, NULL);
94 	if (ret)
95 		return (ret);
96 
97 	return (0);
98 }
99 
100 
101 #define NO_SUCH_FILE	EOPNOTSUPP
102 static int
103 find_best_pivot_pvdb(const char *src, const char *dst, char *pivot,
104     size_t pvlen, unsigned long *rnorm)
105 {
106 	struct _citrus_db *db1, *db2, *db3;
107 	struct _region fr, r1, r2;
108 	char buf[LINE_MAX];
109 	uint32_t val32;
110 	unsigned long norm;
111 	int i, num, ret;
112 
113 	ret = _map_file(&fr, CS_PIVOT ".pvdb");
114 	if (ret) {
115 		if (ret == ENOENT)
116 			ret = NO_SUCH_FILE;
117 		return (ret);
118 	}
119 	ret = _db_open(&db1, &fr, _CITRUS_PIVOT_MAGIC, _db_hash_std, NULL);
120 	if (ret)
121 		goto quit1;
122 	ret = open_subdb(&db2, db1, src);
123 	if (ret)
124 		goto quit2;
125 
126 	num = _db_get_num_entries(db2);
127 	*rnorm = ULONG_MAX;
128 	for (i = 0; i < num; i++) {
129 		/* iterate each pivot */
130 		ret = _db_get_entry(db2, i, &r1, &r2);
131 		if (ret)
132 			goto quit3;
133 		/* r1:pivot name, r2:norm among src and pivot */
134 		ret = get32(&r2, &val32);
135 		if (ret)
136 			goto quit3;
137 		norm = val32;
138 		snprintf(buf, sizeof(buf), "%.*s",
139 			 (int)_region_size(&r1), (char *)_region_head(&r1));
140 		/* buf: pivot name */
141 		ret = open_subdb(&db3, db1, buf);
142 		if (ret)
143 			goto quit3;
144 		if (_db_lookup_by_s(db3, dst, &r2, NULL) != 0)
145 			/* don't break the loop, test all src/dst pairs. */
146 			goto quit4;
147 		/* r2: norm among pivot and dst */
148 		ret = get32(&r2, &val32);
149 		if (ret)
150 			goto quit4;
151 		norm += val32;
152 		/* judge minimum norm */
153 		if (norm < *rnorm) {
154 			*rnorm = norm;
155 			strlcpy(pivot, buf, pvlen);
156 		}
157 quit4:
158 		_db_close(db3);
159 		if (ret)
160 			goto quit3;
161 	}
162 quit3:
163 	_db_close(db2);
164 quit2:
165 	_db_close(db1);
166 quit1:
167 	_unmap_file(&fr);
168 	if (ret)
169 		return (ret);
170 
171 	if (*rnorm == ULONG_MAX)
172 		return (ENOENT);
173 
174 	return (0);
175 }
176 
177 /* ---------------------------------------------------------------------- */
178 
179 struct zone {
180 	const char *begin, *end;
181 };
182 
183 struct parse_arg {
184 	char dst[PATH_MAX];
185 	unsigned long norm;
186 };
187 
188 static int
189 parse_line(struct parse_arg *pa, struct _region *r)
190 {
191 	struct zone z1, z2;
192 	char buf[20];
193 	size_t len;
194 
195 	len = _region_size(r);
196 	z1.begin = _bcs_skip_ws_len(_region_head(r), &len);
197 	if (len == 0)
198 		return (EFTYPE);
199 	z1.end = _bcs_skip_nonws_len(z1.begin, &len);
200 	if (len == 0)
201 		return (EFTYPE);
202 	z2.begin = _bcs_skip_ws_len(z1.end, &len);
203 	if (len == 0)
204 		return (EFTYPE);
205 	z2.end = _bcs_skip_nonws_len(z2.begin, &len);
206 
207 	/* z1 : dst name, z2 : norm */
208 	snprintf(pa->dst, sizeof(pa->dst),
209 	    "%.*s", (int)(z1.end-z1.begin), z1.begin);
210 	snprintf(buf, sizeof(buf),
211 	    "%.*s", (int)(z2.end-z2.begin), z2.begin);
212 	pa->norm = _bcs_strtoul(buf, NULL, 0);
213 
214 	return (0);
215 }
216 
217 static int
218 find_dst(struct parse_arg *pasrc, const char *dst)
219 {
220 	struct _lookup *cl;
221 	struct parse_arg padst;
222 	struct _region data;
223 	int ret;
224 
225 	ret = _lookup_seq_open(&cl, CS_PIVOT, _LOOKUP_CASE_IGNORE);
226 	if (ret)
227 		return (ret);
228 
229 	ret = _lookup_seq_lookup(cl, pasrc->dst, &data);
230 	while (ret == 0) {
231 		ret = parse_line(&padst, &data);
232 		if (ret)
233 			break;
234 		if (strcmp(dst, padst.dst) == 0) {
235 			pasrc->norm += padst.norm;
236 			break;
237 		}
238 		ret = _lookup_seq_next(cl, NULL, &data);
239 	}
240 	_lookup_seq_close(cl);
241 
242 	return (ret);
243 }
244 
245 static int
246 find_best_pivot_lookup(const char *src, const char *dst, char *pivot,
247     size_t pvlen, unsigned long *rnorm)
248 {
249 	struct _lookup *cl;
250 	struct _region data;
251 	struct parse_arg pa;
252 	char pivot_min[PATH_MAX];
253 	unsigned long norm_min;
254 	int ret;
255 
256 	ret = _lookup_seq_open(&cl, CS_PIVOT, _LOOKUP_CASE_IGNORE);
257 	if (ret)
258 		return (ret);
259 
260 	norm_min = ULONG_MAX;
261 
262 	/* find pivot code */
263 	ret = _lookup_seq_lookup(cl, src, &data);
264 	while (ret == 0) {
265 		ret = parse_line(&pa, &data);
266 		if (ret)
267 			break;
268 		ret = find_dst(&pa, dst);
269 		if (ret)
270 			break;
271 		if (pa.norm < norm_min) {
272 			norm_min = pa.norm;
273 			strlcpy(pivot_min, pa.dst, sizeof(pivot_min));
274 		}
275 		ret = _lookup_seq_next(cl, NULL, &data);
276 	}
277 	_lookup_seq_close(cl);
278 
279 	if (ret != ENOENT)
280 		return (ret);
281 	if (norm_min == ULONG_MAX)
282 		return (ENOENT);
283 	strlcpy(pivot, pivot_min, pvlen);
284 	if (rnorm)
285 		*rnorm = norm_min;
286 
287 	return (0);
288 }
289 
290 static int
291 find_best_pivot(const char *src, const char *dst, char *pivot, size_t pvlen,
292     unsigned long *rnorm)
293 {
294 	int ret;
295 
296 	ret = find_best_pivot_pvdb(src, dst, pivot, pvlen, rnorm);
297 	if (ret == NO_SUCH_FILE)
298 		ret = find_best_pivot_lookup(src, dst, pivot, pvlen, rnorm);
299 
300 	return (ret);
301 }
302 
303 static __inline int
304 open_serial_mapper(struct _citrus_mapper_area *__restrict ma,
305     struct _citrus_mapper * __restrict * __restrict rcm,
306     const char *src, const char *pivot, const char *dst)
307 {
308 	char buf[PATH_MAX];
309 
310 	snprintf(buf, sizeof(buf), "%s/%s,%s/%s", src, pivot, pivot, dst);
311 
312 	return (_mapper_open_direct(ma, rcm, "mapper_serial", buf));
313 }
314 
315 static struct _citrus_csmapper *csm_none = NULL;
316 static int
317 get_none(struct _citrus_mapper_area *__restrict ma,
318     struct _citrus_csmapper *__restrict *__restrict rcsm)
319 {
320 	int ret;
321 
322 	WLOCK(&ma_lock);
323 	if (csm_none) {
324 		*rcsm = csm_none;
325 		ret = 0;
326 		goto quit;
327 	}
328 
329 	ret = _mapper_open_direct(ma, &csm_none, "mapper_none", "");
330 	if (ret)
331 		goto quit;
332 	_mapper_set_persistent(csm_none);
333 
334 	*rcsm = csm_none;
335 	ret = 0;
336 quit:
337 	UNLOCK(&ma_lock);
338 	return (ret);
339 }
340 
341 int
342 _citrus_csmapper_open(struct _citrus_csmapper * __restrict * __restrict rcsm,
343     const char * __restrict src, const char * __restrict dst, uint32_t flags,
344     unsigned long *rnorm)
345 {
346 	const char *realsrc, *realdst;
347 	char buf1[PATH_MAX], buf2[PATH_MAX], key[PATH_MAX], pivot[PATH_MAX];
348 	unsigned long norm;
349 	int ret;
350 
351 	norm = 0;
352 
353 	ret = _citrus_mapper_create_area(&maparea, _PATH_CSMAPPER);
354 	if (ret)
355 		return (ret);
356 
357 	realsrc = _lookup_alias(CS_ALIAS, src, buf1, sizeof(buf1),
358 	    _LOOKUP_CASE_IGNORE);
359 	realdst = _lookup_alias(CS_ALIAS, dst, buf2, sizeof(buf2),
360 	    _LOOKUP_CASE_IGNORE);
361 	if (!strcmp(realsrc, realdst)) {
362 		ret = get_none(maparea, rcsm);
363 		if (ret == 0 && rnorm != NULL)
364 			*rnorm = 0;
365 		return (ret);
366 	}
367 
368 	snprintf(key, sizeof(key), "%s/%s", realsrc, realdst);
369 
370 	ret = _mapper_open(maparea, rcsm, key);
371 	if (ret == 0) {
372 		if (rnorm != NULL)
373 			*rnorm = 0;
374 		return (0);
375 	}
376 	if (ret != ENOENT || (flags & _CSMAPPER_F_PREVENT_PIVOT)!=0)
377 		return (ret);
378 
379 	ret = find_best_pivot(realsrc, realdst, pivot, sizeof(pivot), &norm);
380 	if (ret)
381 		return (ret);
382 
383 	ret = open_serial_mapper(maparea, rcsm, realsrc, pivot, realdst);
384 	if (ret == 0 && rnorm != NULL)
385 		*rnorm = norm;
386 
387 	return (ret);
388 }
389