lib/libc/citrus/citrus_mapper.c

   1 /*      $NetBSD: citrus_mapper.c,v 1.7 2008/07/25 14:05:25 christos 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_mapper.c,v 1.7 2008/07/25 14:05:25 christos 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 <sys/types.h>
  43 #include <sys/stat.h>
  44 #include <sys/queue.h>
  45
  46 #include "citrus_namespace.h"
  47 #include "citrus_types.h"
  48 #include "citrus_region.h"
  49 #include "citrus_memstream.h"
  50 #include "citrus_bcs.h"
  51 #include "citrus_mmap.h"
  52 #include "citrus_module.h"
  53 #include "citrus_hash.h"
  54 #include "citrus_mapper.h"
  55
  56 #define _CITRUS_MAPPER_DIR      "mapper.dir"
  57
  58 #define CM_HASH_SIZE 101
  59 #define REFCOUNT_PERSISTENT     -1
  60
  61 #ifdef _REENTRANT
  62 static rwlock_t lock = RWLOCK_INITIALIZER;
  63 #endif
  64
  65 struct _citrus_mapper_area {
  66         _CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE)       ma_cache;
  67         char                                                    *ma_dir;
  68 };
  69
  70 /*
  71  * _citrus_mapper_create_area:
  72  *      create mapper area
  73  */
  74
  75 int
  76 _citrus_mapper_create_area(
  77         struct _citrus_mapper_area *__restrict *__restrict rma,
  78         const char *__restrict area)
  79 {
  80         struct stat st;
  81         int ret;
  82         char path[PATH_MAX];
  83         struct _citrus_mapper_area *ma;
  84
  85         rwlock_wrlock(&lock);
  86
  87         if (*rma != NULL) {
  88                 ret = 0;
  89                 goto quit;
  90         }
  91
  92         snprintf(path, (size_t)PATH_MAX, "%s/%s", area, _CITRUS_MAPPER_DIR);
  93
  94         ret = stat(path, &st);
  95         if (ret)
  96                 goto quit;
  97
  98         ma = malloc(sizeof(*ma));
  99         if (ma == NULL) {
 100                 ret = errno;
 101                 goto quit;
 102         }
 103         ma->ma_dir = strdup(area);
 104         if (ma->ma_dir == NULL) {
 105                 ret = errno;
 106                 free(ma->ma_dir);
 107                 goto quit;
 108         }
 109         _CITRUS_HASH_INIT(&ma->ma_cache, CM_HASH_SIZE);
 110
 111         *rma = ma;
 112         ret = 0;
 113 quit:
 114         rwlock_unlock(&lock);
 115
 116         return ret;
 117 }
 118
 119
 120 /*
 121  * lookup_mapper_entry:
 122  *      lookup mapper.dir entry in the specified directory.
 123  *
 124  * line format of iconv.dir file:
 125  *      mapper  module  arg
 126  * mapper : mapper name.
 127  * module : mapper module name.
 128  * arg    : argument for the module (generally, description file name)
 129  */
 130
 131 static int
 132 lookup_mapper_entry(const char *dir, const char *mapname,
 133                     void *linebuf, size_t linebufsize,
 134                     const char **module, const char **variable)
 135 {
 136         struct _region r;
 137         struct _memstream ms;
 138         int ret;
 139         const char *cp, *cq;
 140         char *p;
 141         size_t len;
 142         char path[PATH_MAX];
 143
 144         /* create mapper.dir path */
 145         snprintf(path, (size_t)PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
 146
 147         /* open read stream */
 148         ret = _map_file(&r, path);
 149         if (ret)
 150                 return ret;
 151
 152         _memstream_bind(&ms, &r);
 153
 154         /* search the line matching to the map name */
 155         cp = _memstream_matchline(&ms, mapname, &len, 0);
 156         if (!cp) {
 157                 ret = ENOENT;
 158                 goto quit;
 159         }
 160         if (!len || len>linebufsize-1) {
 161                 ret = EINVAL;
 162                 goto quit;
 163         }
 164
 165         p = linebuf;
 166         /* get module name */
 167         *module = p;
 168         cq = _bcs_skip_nonws_len(cp, &len);
 169         strlcpy(p, cp, (size_t)(cq-cp+1));
 170         p += cq-cp+1;
 171
 172         /* get variable */
 173         *variable = p;
 174         cp = _bcs_skip_ws_len(cq, &len);
 175         strlcpy(p, cp, len+1);
 176
 177         ret = 0;
 178
 179 quit:
 180         _unmap_file(&r);
 181         return ret;
 182 }
 183
 184 /*
 185  * mapper_close:
 186  *      simply close a mapper. (without handling hash)
 187  */
 188 static void
 189 mapper_close(struct _citrus_mapper *cm)
 190 {
 191         if (cm->cm_module) {
 192                 if (cm->cm_ops) {
 193                         if (cm->cm_closure)
 194                                 (*cm->cm_ops->mo_uninit)(cm);
 195                         free(cm->cm_ops);
 196                 }
 197                 _citrus_unload_module(cm->cm_module);
 198         }
 199         free(cm->cm_traits);
 200         free(cm);
 201 }
 202
 203 /*
 204  * mapper_open:
 205  *      simply open a mapper. (without handling hash)
 206  */
 207 static int
 208 mapper_open(struct _citrus_mapper_area *__restrict ma,
 209             struct _citrus_mapper * __restrict * __restrict rcm,
 210             const char * __restrict module,
 211             const char * __restrict variable)
 212 {
 213         int ret;
 214         struct _citrus_mapper *cm;
 215         _citrus_mapper_getops_t getops;
 216
 217         /* initialize mapper handle */
 218         cm = malloc(sizeof(*cm));
 219         if (!cm)
 220                 return errno;
 221
 222         cm->cm_module = NULL;
 223         cm->cm_ops = NULL;
 224         cm->cm_closure = NULL;
 225         cm->cm_traits = NULL;
 226         cm->cm_refcount = 0;
 227         cm->cm_key = NULL;
 228
 229         /* load module */
 230         ret = _citrus_load_module(&cm->cm_module, module);
 231         if (ret)
 232                 goto err;
 233
 234         /* get operators */
 235         getops = (_citrus_mapper_getops_t)
 236             _citrus_find_getops(cm->cm_module, module, "mapper");
 237         if (!getops) {
 238                 ret = EOPNOTSUPP;
 239                 goto err;
 240         }
 241         cm->cm_ops = malloc(sizeof(*cm->cm_ops));
 242         if (!cm->cm_ops) {
 243                 ret = errno;
 244                 goto err;
 245         }
 246         ret = (*getops)(cm->cm_ops, sizeof(*cm->cm_ops),
 247                         _CITRUS_MAPPER_ABI_VERSION);
 248         if (ret)
 249                 goto err;
 250
 251         if (!cm->cm_ops->mo_init ||
 252             !cm->cm_ops->mo_uninit ||
 253             !cm->cm_ops->mo_convert ||
 254             !cm->cm_ops->mo_init_state)
 255                 goto err;
 256
 257         /* allocate traits structure */
 258         cm->cm_traits = malloc(sizeof(*cm->cm_traits));
 259         if (cm->cm_traits == NULL) {
 260                 ret = errno;
 261                 goto err;
 262         }
 263         /* initialize the mapper */
 264         ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
 265                                      (const void *)variable,
 266                                      strlen(variable)+1,
 267                                      cm->cm_traits, sizeof(*cm->cm_traits));
 268         if (ret)
 269                 goto err;
 270
 271         *rcm = cm;
 272
 273         return 0;
 274
 275 err:
 276         mapper_close(cm);
 277         return ret;
 278 }
 279
 280 /*
 281  * _citrus_mapper_open_direct:
 282  *      open a mapper.
 283  */
 284 int
 285 _citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
 286                            struct _citrus_mapper * __restrict * __restrict rcm,
 287                            const char * __restrict module,
 288                            const char * __restrict variable)
 289 {
 290         return mapper_open(ma, rcm, module, variable);
 291 }
 292
 293 /*
 294  * hash_func
 295  */
 296 static __inline int
 297 hash_func(const char *key)
 298 {
 299         return _string_hash_func(key, CM_HASH_SIZE);
 300 }
 301
 302 /*
 303  * match_func
 304  */
 305 static __inline int
 306 match_func(struct _citrus_mapper *cm, const char *key)
 307 {
 308         return strcmp(cm->cm_key, key);
 309 }
 310
 311 /*
 312  * _citrus_mapper_open:
 313  *      open a mapper with looking up "mapper.dir".
 314  */
 315 int
 316 _citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
 317                     struct _citrus_mapper * __restrict * __restrict rcm,
 318                     const char * __restrict mapname)
 319 {
 320         int ret;
 321         char linebuf[PATH_MAX];
 322         const char *module, *variable = NULL;
 323         struct _citrus_mapper *cm;
 324         int hashval;
 325
 326         rwlock_wrlock(&lock);
 327
 328         /* search in the cache */
 329         hashval = hash_func(mapname);
 330         _CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
 331                             hashval);
 332         if (cm) {
 333                 /* found */
 334                 cm->cm_refcount++;
 335                 *rcm = cm;
 336                 ret = 0;
 337                 goto quit;
 338         }
 339
 340         /* search mapper entry */
 341         ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf,
 342             (size_t)PATH_MAX, &module, &variable);
 343         if (ret)
 344                 goto quit;
 345
 346         /* open mapper */
 347         ret = mapper_open(ma, &cm, module, variable);
 348         if (ret)
 349                 goto quit;
 350         cm->cm_key = strdup(mapname);
 351         if (cm->cm_key == NULL) {
 352                 ret = errno;
 353                 rwlock_unlock(&lock);
 354                 _mapper_close(cm);
 355                 return ret;
 356         }
 357
 358         /* insert to the cache */
 359         cm->cm_refcount = 1;
 360         _CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
 361
 362         *rcm = cm;
 363         ret = 0;
 364 quit:
 365         rwlock_unlock(&lock);
 366         return ret;
 367 }
 368
 369 /*
 370  * _citrus_mapper_close:
 371  *      close the specified mapper.
 372  */
 373 void
 374 _citrus_mapper_close(struct _citrus_mapper *cm)
 375 {
 376         if (cm) {
 377                 rwlock_wrlock(&lock);
 378                 if (cm->cm_refcount == REFCOUNT_PERSISTENT)
 379                         goto quit;
 380                 if (cm->cm_refcount > 0) {
 381                         if (--cm->cm_refcount > 0)
 382                                 goto quit;
 383                         _CITRUS_HASH_REMOVE(cm, cm_entry);
 384                         free(cm->cm_key);
 385                 }
 386                 rwlock_unlock(&lock);
 387                 mapper_close(cm);
 388                 return;
 389 quit:
 390                 rwlock_unlock(&lock);
 391         }
 392 }
 393
 394 /*
 395  * _citrus_mapper_set_persistent:
 396  *      set persistent count.
 397  */
 398 void
 399 _citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
 400 {
 401         rwlock_wrlock(&lock);
 402         cm->cm_refcount = REFCOUNT_PERSISTENT;
 403         rwlock_unlock(&lock);
 404 }