lib/libc/citrus/citrus_iconv.c

   1 /*      $NetBSD: citrus_iconv.c,v 1.8 2009/09/05 06:44:27 dholland 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 1.8 2009/09/05 06:44:27 dholland Exp $");
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include "namespace.h"
  35 #include "reentrant.h"
  36 #include <assert.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <errno.h>
  41 #include <limits.h>
  42 #include <unistd.h>
  43 #include <paths.h>
  44 #include <dirent.h>
  45 #include <sys/types.h>
  46 #include <sys/queue.h>
  47
  48 #include "citrus_namespace.h"
  49 #include "citrus_bcs.h"
  50 #include "citrus_region.h"
  51 #include "citrus_memstream.h"
  52 #include "citrus_mmap.h"
  53 #include "citrus_module.h"
  54 #include "citrus_lookup.h"
  55 #include "citrus_hash.h"
  56 #include "citrus_iconv.h"
  57
  58 #define _CITRUS_ICONV_DIR       "iconv.dir"
  59 #define _CITRUS_ICONV_ALIAS     "iconv.alias"
  60
  61 #define CI_HASH_SIZE 101
  62 #define CI_INITIAL_MAX_REUSE    5
  63 #define CI_ENV_MAX_REUSE        "ICONV_MAX_REUSE"
  64
  65 #ifdef _REENTRANT
  66 static rwlock_t lock = RWLOCK_INITIALIZER;
  67 #endif
  68 static int isinit = 0;
  69 static _CITRUS_HASH_HEAD(, _citrus_iconv_shared, CI_HASH_SIZE) shared_pool;
  70 static TAILQ_HEAD(, _citrus_iconv_shared) shared_unused;
  71 static int shared_num_unused, shared_max_reuse;
  72
  73 static __inline void
  74 init_cache(void)
  75 {
  76         rwlock_wrlock(&lock);
  77         if (!isinit) {
  78                 _CITRUS_HASH_INIT(&shared_pool, CI_HASH_SIZE);
  79                 TAILQ_INIT(&shared_unused);
  80                 shared_max_reuse = -1;
  81                 if (!issetugid() && getenv(CI_ENV_MAX_REUSE))
  82                         shared_max_reuse = atoi(getenv(CI_ENV_MAX_REUSE));
  83                 if (shared_max_reuse < 0)
  84                         shared_max_reuse = CI_INITIAL_MAX_REUSE;
  85                 isinit = 1;
  86         }
  87         rwlock_unlock(&lock);
  88 }
  89
  90 /*
  91  * lookup_iconv_entry:
  92  *      lookup iconv.dir entry in the specified directory.
  93  *
  94  * line format of iconv.dir file:
  95  *      key  module  arg
  96  * key    : lookup key.
  97  * module : iconv module name.
  98  * arg    : argument for the module (generally, description file name)
  99  *
 100  */
 101 static __inline int
 102 lookup_iconv_entry(const char *curdir, const char *key,
 103                    char *linebuf, size_t linebufsize,
 104                    const char **module, const char **variable)
 105 {
 106         const char *cp, *cq;
 107         char *p, path[PATH_MAX];
 108
 109         /* iconv.dir path */
 110         snprintf(path, (size_t)PATH_MAX, ("%s/" _CITRUS_ICONV_DIR), curdir);
 111
 112         /* lookup db */
 113         cp = p = _lookup_simple(path, key, linebuf, linebufsize,
 114                                 _LOOKUP_CASE_IGNORE);
 115         if (p == NULL)
 116                 return ENOENT;
 117
 118         /* get module name */
 119         *module = p;
 120         cq = _bcs_skip_nonws(cp);
 121         p[cq-cp] = '\0';
 122         p += cq-cp+1;
 123         cq++;
 124
 125         /* get variable */
 126         cp = _bcs_skip_ws(cq);
 127         *variable = p += cp - cq;
 128         cq = _bcs_skip_nonws(cp);
 129         p[cq-cp] = '\0';
 130
 131         return 0;
 132 }
 133
 134 static __inline void
 135 close_shared(struct _citrus_iconv_shared *ci)
 136 {
 137         if (ci) {
 138                 if (ci->ci_module) {
 139                         if (ci->ci_ops) {
 140                                 if (ci->ci_closure)
 141                                         (*ci->ci_ops->io_uninit_shared)(ci);
 142                                 free(ci->ci_ops);
 143                         }
 144                         _citrus_unload_module(ci->ci_module);
 145                 }
 146                 free(ci);
 147         }
 148 }
 149
 150 static __inline int
 151 open_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
 152             const char * __restrict basedir, const char * __restrict convname,
 153             const char * __restrict src, const char * __restrict dst)
 154 {
 155         int ret;
 156         struct _citrus_iconv_shared *ci;
 157         _citrus_iconv_getops_t getops;
 158         char linebuf[LINE_MAX];
 159         const char *module, *variable;
 160         size_t len_convname;
 161
 162         /* search converter entry */
 163         ret = lookup_iconv_entry(basedir, convname, linebuf, sizeof(linebuf),
 164                                  &module, &variable);
 165         if (ret) {
 166                 if (ret == ENOENT)
 167                         /* fallback */
 168                         ret = lookup_iconv_entry(basedir, "*",
 169                                                  linebuf, sizeof(linebuf),
 170                                                  &module, &variable);
 171                 if (ret)
 172                         return ret;
 173         }
 174
 175         /* initialize iconv handle */
 176         len_convname = strlen(convname);
 177         ci = malloc(sizeof(*ci)+len_convname+1);
 178         if (!ci) {
 179                 ret = errno;
 180                 goto err;
 181         }
 182         ci->ci_module = NULL;
 183         ci->ci_ops = NULL;
 184         ci->ci_closure = NULL;
 185         ci->ci_convname = (void *)&ci[1];
 186         memcpy(ci->ci_convname, convname, len_convname+1);
 187
 188         /* load module */
 189         ret = _citrus_load_module(&ci->ci_module, module);
 190         if (ret)
 191                 goto err;
 192
 193         /* get operators */
 194         getops = (_citrus_iconv_getops_t)
 195             _citrus_find_getops(ci->ci_module, module, "iconv");
 196         if (!getops) {
 197                 ret = EOPNOTSUPP;
 198                 goto err;
 199         }
 200         ci->ci_ops = malloc(sizeof(*ci->ci_ops));
 201         if (!ci->ci_ops) {
 202                 ret = errno;
 203                 goto err;
 204         }
 205         ret = (*getops)(ci->ci_ops, sizeof(*ci->ci_ops),
 206                         _CITRUS_ICONV_ABI_VERSION);
 207         if (ret)
 208                 goto err;
 209
 210         /* version check */
 211         if (ci->ci_ops->io_abi_version == 1) {
 212                 /* binary compatibility broken at ver.2 */
 213                 ret = EINVAL;
 214                 goto err;
 215         }
 216
 217         if (ci->ci_ops->io_init_shared == NULL ||
 218             ci->ci_ops->io_uninit_shared == NULL ||
 219             ci->ci_ops->io_init_context == NULL ||
 220             ci->ci_ops->io_uninit_context == NULL ||
 221             ci->ci_ops->io_convert == NULL)
 222                 goto err;
 223
 224         /* initialize the converter */
 225         ret = (*ci->ci_ops->io_init_shared)(ci, basedir, src, dst,
 226                                             (const void *)variable,
 227                                             strlen(variable)+1);
 228         if (ret)
 229                 goto err;
 230
 231         *rci = ci;
 232
 233         return 0;
 234 err:
 235         close_shared(ci);
 236         return ret;
 237 }
 238
 239 static __inline int
 240 hash_func(const char *key)
 241 {
 242         return _string_hash_func(key, CI_HASH_SIZE);
 243 }
 244
 245 static __inline int
 246 match_func(struct _citrus_iconv_shared * __restrict ci,
 247            const char * __restrict key)
 248 {
 249         return strcmp(ci->ci_convname, key);
 250 }
 251
 252 static int
 253 get_shared(struct _citrus_iconv_shared * __restrict * __restrict rci,
 254            const char *basedir, const char *src, const char *dst)
 255 {
 256         int ret = 0;
 257         int hashval;
 258         struct _citrus_iconv_shared * ci;
 259         char convname[PATH_MAX];
 260
 261         snprintf(convname, sizeof(convname), "%s/%s", src, dst);
 262
 263         rwlock_wrlock(&lock);
 264
 265         /* lookup alread existing entry */
 266         hashval = hash_func(convname);
 267         _CITRUS_HASH_SEARCH(&shared_pool, ci, ci_hash_entry, match_func,
 268                             convname, hashval);
 269         if (ci != NULL) {
 270                 /* found */
 271                 if (ci->ci_used_count == 0) {
 272                         TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
 273                         shared_num_unused--;
 274                 }
 275                 ci->ci_used_count++;
 276                 *rci = ci;
 277                 goto quit;
 278         }
 279
 280         /* create new entry */
 281         ret = open_shared(&ci, basedir, convname, src, dst);
 282         if (ret)
 283                 goto quit;
 284
 285         _CITRUS_HASH_INSERT(&shared_pool, ci, ci_hash_entry, hashval);
 286         ci->ci_used_count = 1;
 287         *rci = ci;
 288
 289 quit:
 290         rwlock_unlock(&lock);
 291
 292         return ret;
 293 }
 294
 295 static void
 296 release_shared(struct _citrus_iconv_shared * __restrict ci)
 297 {
 298         rwlock_wrlock(&lock);
 299
 300         ci->ci_used_count--;
 301         if (ci->ci_used_count == 0) {
 302                 /* put it into unused list */
 303                 shared_num_unused++;
 304                 TAILQ_INSERT_TAIL(&shared_unused, ci, ci_tailq_entry);
 305                 /* flood out */
 306                 while (shared_num_unused > shared_max_reuse) {
 307                         ci = TAILQ_FIRST(&shared_unused);
 308                         _DIAGASSERT(ci != NULL);
 309                         TAILQ_REMOVE(&shared_unused, ci, ci_tailq_entry);
 310                         _CITRUS_HASH_REMOVE(ci, ci_hash_entry);
 311                         shared_num_unused--;
 312                         close_shared(ci);
 313                 }
 314         }
 315
 316         rwlock_unlock(&lock);
 317 }
 318
 319 /*
 320  * _citrus_iconv_open:
 321  *      open a converter for the specified in/out codes.
 322  */
 323 int
 324 _citrus_iconv_open(struct _citrus_iconv * __restrict * __restrict rcv,
 325                    const char * __restrict basedir,
 326                    const char * __restrict src, const char * __restrict dst)
 327 {
 328         int ret;
 329         struct _citrus_iconv_shared *ci = NULL;
 330         struct _citrus_iconv *cv;
 331         char realsrc[PATH_MAX], realdst[PATH_MAX];
 332         char buf[PATH_MAX], path[PATH_MAX];
 333
 334         init_cache();
 335
 336         /* resolve codeset name aliases */
 337         snprintf(path, sizeof(path), "%s/%s", basedir, _CITRUS_ICONV_ALIAS);
 338         strlcpy(realsrc,
 339                 _lookup_alias(path, src, buf, (size_t)PATH_MAX,
 340                 _LOOKUP_CASE_IGNORE),
 341                 (size_t)PATH_MAX);
 342         strlcpy(realdst,
 343                 _lookup_alias(path, dst, buf, (size_t)PATH_MAX,
 344                 _LOOKUP_CASE_IGNORE),
 345                 (size_t)PATH_MAX);
 346
 347         /* sanity check */
 348         if (strchr(realsrc, '/') != NULL || strchr(realdst, '/'))
 349                 return EINVAL;
 350
 351         /* get shared record */
 352         ret = get_shared(&ci, basedir, realsrc, realdst);
 353         if (ret)
 354                 return ret;
 355
 356         /* create/init context */
 357         cv = malloc(sizeof(*cv));
 358         if (cv == NULL) {
 359                 ret = errno;
 360                 release_shared(ci);
 361                 return ret;
 362         }
 363         cv->cv_shared = ci;
 364         ret = (*ci->ci_ops->io_init_context)(cv);
 365         if (ret) {
 366                 release_shared(ci);
 367                 free(cv);
 368                 return ret;
 369         }
 370         *rcv = cv;
 371
 372         return 0;
 373 }
 374
 375 /*
 376  * _citrus_iconv_close:
 377  *      close the specified converter.
 378  */
 379 void
 380 _citrus_iconv_close(struct _citrus_iconv *cv)
 381 {
 382         if (cv) {
 383                 (*cv->cv_shared->ci_ops->io_uninit_context)(cv);
 384                 release_shared(cv->cv_shared);
 385                 free(cv);
 386         }
 387 }