lib/libc/citrus/citrus_iconv.c

   1 /*      $NetBSD: citrus_iconv.c,v 1.10 2011/11/19 18:34:21 tnozaki Exp $        */
   2
   3 /*-
   4  * Copyright (c)2003 Citrus Project,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 __RCSID("$NetBSD: citrus_iconv.c,v 1.10 2011/11/19 18:34:21 tnozaki Exp $");
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include "namespace.h"
  35 #include "reentrant.h"
  36
  37 #include <sys/types.h>
  38 #include <sys/queue.h>
  39
  40 #include <assert.h>
  41 #include <dirent.h>
  42 #include <errno.h>
  43 #include <limits.h>
  44 #include <paths.h>
  45 #include <stdbool.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50
  51 #include "citrus_namespace.h"
  52 #include "citrus_bcs.h"
  53 #include "citrus_region.h"
  54 #include "citrus_memstream.h"
  55 #include "citrus_mmap.h"
  56 #include "citrus_module.h"
  57 #include "citrus_lookup.h"
  58 #include "citrus_hash.h"
  59 #include "citrus_iconv.h"
  60
  61 #define _CITRUS_ICONV_DIR       "iconv.dir"
  62 #define _CITRUS_ICONV_ALIAS     "iconv.alias"
  63
  64 #define CI_HASH_SIZE 101
  65 #define CI_INITIAL_MAX_REUSE    5
  66 #define CI_ENV_MAX_REUSE        "ICONV_MAX_REUSE"
  67
  68 #ifdef _REENTRANT
  69 static rwlock_t lock = RWLOCK_INITIALIZER;
  70 #endif
  71
  72 static bool isinit = false;
  73 static _CITRUS_HASH_HEAD(, _citrus_iconv_shared, CI_HASH_SIZE) shared_pool;
  74 static TAILQ_HEAD(, _citrus_iconv_shared) shared_unused;
  75 static int shared_num_unused, shared_max_reuse;
  76
  77 static __inline void
  78 init_cache(void)
  79 {
  80         rwlock_wrlock(&lock);
  81         if (!isinit) {
  82                 _CITRUS_HASH_INIT(&shared_pool, CI_HASH_SIZE);
  83                 TAILQ_INIT(&shared_unused);
  84                 shared_max_reuse = -1;
  85                 if (!issetugid() && getenv(CI_ENV_MAX_REUSE))
  86                         shared_max_reuse = atoi(getenv(CI_ENV_MAX_REUSE));
  87                 if (shared_max_reuse < 0)
  88                         shared_max_reuse = CI_INITIAL_MAX_REUSE;
  89                 isinit = true;
  90         }
  91         rwlock_unlock(&lock);
  92 }
  93
  94 /*
  95  * lookup_iconv_entry:
  96  *      lookup iconv.dir entry in the specified directory.
  97  *
  98  * line format of iconv.dir file:
  99  *      key  module  arg
 100  * key    : lookup key.
 101  * module : iconv module name.
 102  * arg    : argument for the module (generally, description file name)
 103  *
 104  */
 105 static __inline int
 106 lookup_iconv_entry(const char *curdir, const char *key,
 107                    char *linebuf, size_t linebufsize,
 108                    const char **module, const char **variable)
 109 {
 110         const char *cp, *cq;
 111         char *p, path[PATH_MAX];
 112
 113         /* iconv.dir path */
 114         snprintf(path, (size_t)PATH_MAX, ("%s/" _CITRUS_ICONV_DIR), curdir);
 115
 116         /* lookup db */
 117         cp = p = _lookup_simple(path, key, linebuf, linebufsize,
 118                                 _LOOKUP_CASE_IGNORE);
 119         if (p == NULL)
 120                 return ENOENT;
 121
 122         /* get module name */
 123         *module = p;
 124         cq = _bcs_skip_nonws(cp);
 125         p[cq-cp] = '\0';
 126         p += cq-cp+1;
 127         cq++;
 128
 129         /* get variable */
 130         cp = _bcs_skip_ws(cq);
 131         *variable = p += cp - cq;
 132         cq = _bcs_skip_nonws(cp);
 133         p[cq-cp] = '\0';
 134
 135         return 0;
 136 }
 137
 138 static __inline void
 139 close_shared(struct _citrus_iconv_shared *ci)
 140 {
 141         if (ci) {
 142                 if (ci->ci_module) {
 143                         if (ci->ci_ops) {
 144                                 if (ci->ci_closure)
 145                                         (*ci->ci_ops->io_uninit_shared)(ci);
 146                                 free(ci->ci_ops);
 147                         }
 148                         _citrus_unload_module(ci->ci_module);
 149                 }
 150                 free(ci);
 151         }
 152 }
 153
 154 static __inline int
 155 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
 156             const char * __restrict basedir, const char * __restrict convname,
 157             const char * __restrict src, const char * __restrict dst)
 158 {
 159         int ret;
 160         struct _citrus_iconv_shared *ci;
 161         _citrus_iconv_getops_t getops;
 162         char linebuf[LINE_MAX];
 163         const char *module, *variable;
 164         size_t len_convname;
 165
 166         /* search converter entry */
 167         ret = lookup_iconv_entry(basedir, convname, linebuf, sizeof(linebuf),
 168                                  &module, &variable);
 169         if (ret) {
 170                 if (ret == ENOENT)
 171                         /* fallback */
 172                         ret = lookup_iconv_entry(basedir, "*",
 173                                                  linebuf, sizeof(linebuf),
 174                                                  &module, &variable);
 175                 if (ret)
 176                         return ret;
 177         }
 178
 179         /* initialize iconv handle */
 180         len_convname = strlen(convname);
 181         ci = malloc(sizeof(*ci)+len_convname+1);
 182         if (!ci) {
 183                 ret = errno;
 184                 goto err;
 185         }
 186         ci->ci_module = NULL;
 187         ci->ci_ops = NULL;
 188         ci->ci_closure = NULL;
 189         ci->ci_convname = (void *)&ci[1];
 190         memcpy(ci->ci_convname, convname, len_convname+1);
 191
 192         /* load module */
 193         ret = _citrus_load_module(&ci->ci_module, module);
 194         if (ret)
 195                 goto err;
 196
 197         /* get operators */
 198         getops = (_citrus_iconv_getops_t)
 199             _citrus_find_getops(ci->ci_module, module, "iconv");
 200         if (!getops) {
 201                 ret = EOPNOTSUPP;
 202                 goto err;
 203         }
 204         ci->ci_ops = malloc(sizeof(*ci->ci_ops));
 205         if (!ci->ci_ops) {
 206                 ret = errno;
 207                 goto err;
 208         }
 209         ret = (*getops)(ci->ci_ops, sizeof(*ci->ci_ops),
 210                         _CITRUS_ICONV_ABI_VERSION);
 211         if (ret)
 212                 goto err;
 213
 214         /* version check */
 215         if (ci->ci_ops->io_abi_version == 1) {
 216                 /* binary compatibility broken at ver.2 */
 217                 ret = EINVAL;
 218                 goto err;
 219         }
 220
 221         if (ci->ci_ops->io_init_shared == NULL ||
 222             ci->ci_ops->io_uninit_shared == NULL ||
 223             ci->ci_ops->io_init_context == NULL ||
 224             ci->ci_ops->io_uninit_context == NULL ||
 225             ci->ci_ops->io_convert == NULL) {
 226                 ret = EINVAL;
 227                 goto err;
 228         }
 229
 230         /* initialize the converter */
 231         ret = (*ci->ci_ops->io_init_shared)(ci, basedir, src, dst,
 232                                             (const void *)variable,
 233                                             strlen(variable)+1);
 234         if (ret)
 235                 goto err;
 236
 237         *rci = ci;
 238
 239         return 0;
 240 err:
 241         close_shared(ci);
 242         return ret;
 243 }
 244
 245 static __inline int
 246 hash_func(const char *key)
 247 {
 248         return _string_hash_func(key, CI_HASH_SIZE);
 249 }
 250
 251 static __inline int
 252 match_func(struct _citrus_iconv_shared * __restrict ci,
 253            const char * __restrict key)
 254 {
 255         return strcmp(ci->ci_convname, key);
 256 }
 257
 258 static int
 259 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
 260            const char *basedir, const char *src, const char *dst)
 261 {
 262         int ret = 0;
 263         int hashval;
 264         struct _citrus_iconv_shared * ci;
 265         char convname[PATH_MAX];
 266
 267         snprintf(convname, sizeof(convname), "%s/%s", src, dst);
 268
 269         rwlock_wrlock(&lock);
 270
 271         /* lookup alread existing entry */
 272         hashval = hash_func(convname);
 273         _CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
 274                             convname, hashval);
 275         if (ci != NULL) {
 276                 /* found */
 277                 if (ci->ci_used_count == 0) {
 278                         TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
 279                         shared_num_unused--;
 280                 }
 281                 ci->ci_used_count++;
 282                 *rci = ci;
 283                 goto quit;
 284         }
 285
 286         /* create new entry */
 287         ret = open_shared(&ci, basedir, convname, src, dst);
 288         if (ret)
 289                 goto quit;
 290
 291         _CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
 292         ci->ci_used_count = 1;
 293         *rci = ci;
 294
 295 quit:
 296         rwlock_unlock(&lock);
 297
 298         return ret;
 299 }
 300
 301 static void
 302 release_shared(struct _citrus_iconv_shared * __restrict ci)
 303 {
 304         rwlock_wrlock(&lock);
 305
 306         ci->ci_used_count--;
 307         if (ci->ci_used_count == 0) {
 308                 /* put it into unused list */
 309                 shared_num_unused++;
 310                 TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
 311                 /* flood out */
 312                 while (shared_num_unused > shared_max_reuse) {
 313                         ci = TAILQ_FIRST(&shared_unused);
 314                         _DIAGASSERT(ci != NULL);
 315                         TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
 316                         _CITRUS_HASH_REMOVE(ci, ci_hash_entry);
 317                         shared_num_unused--;
 318                         close_shared(ci);
 319                 }
 320         }
 321
 322         rwlock_unlock(&lock);
 323 }
 324
 325 /*
 326  * _citrus_iconv_open:
 327  *      open a converter for the specified in/out codes.
 328  */
 329 int
 330 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
 331                    const char * __restrict basedir,
 332                    const char * __restrict src, const char * __restrict dst)
 333 {
 334         int ret;
 335         struct _citrus_iconv_shared *ci = NULL;
 336         struct _citrus_iconv *cv;
 337         char realsrc[PATH_MAX], realdst[PATH_MAX];
 338         char buf[PATH_MAX], path[PATH_MAX];
 339
 340         init_cache();
 341
 342         /* resolve codeset name aliases */
 343         snprintf(path, sizeof(path), "%s/%s", basedir, _CITRUS_ICONV_ALIAS);
 344         strlcpy(realsrc,
 345                 _lookup_alias(path, src, buf, (size_t)PATH_MAX,
 346                 _LOOKUP_CASE_IGNORE),
 347                 (size_t)PATH_MAX);
 348         strlcpy(realdst,
 349                 _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
 350                 _LOOKUP_CASE_IGNORE),
 351                 (size_t)PATH_MAX);
 352
 353         /* sanity check */
 354         if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
 355                 return EINVAL;
 356
 357         /* get shared record */
 358         ret = get_shared(&ci, basedir, realsrc, realdst);
 359         if (ret)
 360                 return ret;
 361
 362         /* create/init context */
 363         cv = malloc(sizeof(*cv));
 364         if (cv == NULL) {
 365                 ret = errno;
 366                 release_shared(ci);
 367                 return ret;
 368         }
 369         cv->cv_shared = ci;
 370         ret = (*ci->ci_ops->io_init_context)(cv);
 371         if (ret) {
 372                 release_shared(ci);
 373                 free(cv);
 374                 return ret;
 375         }
 376         *rcv = cv;
 377
 378         return 0;
 379 }
 380
 381 /*
 382  * _citrus_iconv_close:
 383  *      close the specified converter.
 384  */
 385 void
 386 _citrus_iconv_close(struct _citrus_iconv *cv)
 387 {
 388         if (cv) {
 389                 (*cv->cv_shared->ci_ops->io_uninit_context)(cv);
 390                 release_shared(cv->cv_shared);
 391                 free(cv);
 392         }
 393 }