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-rw-r--r--iconv/gconv_cache.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/iconv/gconv_cache.c b/iconv/gconv_cache.c
new file mode 100644
index 0000000000..e204cf1377
--- /dev/null
+++ b/iconv/gconv_cache.c
@@ -0,0 +1,395 @@
+/* Cache handling for iconv modules.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <gconv_int.h>
+#include <iconvconfig.h>
+
+#include "../intl/hash-string.h"
+
+static void *cache;
+static size_t cache_size;
+static int cache_malloced;
+
+
+int
+internal_function
+__gconv_load_cache (void)
+{
+  int fd;
+  struct stat64 st;
+  struct gconvcache_header *header;
+
+  /* We cannot use the cache if the GCONV_PATH environment variable is
+     set.  */
+  __gconv_path_envvar = getenv ("GCONV_PATH");
+  if (__gconv_path_envvar != NULL)
+    return -1;
+
+  /* See whether the cache file exists.  */
+  fd = __open (GCONV_MODULES_CACHE, O_RDONLY);
+  if (__builtin_expect (fd, 0) == -1)
+    /* Not available.  */
+    return -1;
+
+  /* Get information about the file.  */
+  if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0) < 0
+      /* We do not have to start looking at the file if it cannot contain
+	 at least the cache header.  */
+      || st.st_size < sizeof (struct gconvcache_header))
+    {
+    close_and_exit:
+      close (fd);
+      return -1;
+    }
+
+  /* Make the file content available.  */
+  cache_size = st.st_size;
+#ifdef _POSIX_MAPPED_FILES
+  cache = __mmap (NULL, cache_size, PROT_READ, MAP_SHARED, fd, 0);
+  if (__builtin_expect (cache == MAP_FAILED, 0))
+#endif
+    {
+      size_t already_read;
+
+      cache = malloc (cache_size);
+      if (cache == NULL)
+	goto close_and_exit;
+
+      already_read = 0;
+      do
+	{
+	  ssize_t n = __read (fd, (char *) cache + already_read,
+			      cache_size - already_read);
+	  if (__builtin_expect (n, 0) == -1)
+	    {
+	      free (cache);
+	      cache = NULL;
+	      goto close_and_exit;
+	    }
+
+	  already_read += n;
+	}
+      while (already_read < cache_size);
+
+      cache_malloced = 1;
+    }
+
+  /* We don't need the file descriptor anymore.  */
+  close (fd);
+
+  /* Check the consistency.  */
+  header = (struct gconvcache_header *) cache;
+  if (__builtin_expect (header->magic, GCONVCACHE_MAGIC) != GCONVCACHE_MAGIC
+      || __builtin_expect (header->string_offset >= cache_size, 0)
+      || __builtin_expect (header->hash_offset >= cache_size, 0)
+      || __builtin_expect (header->hash_size == 0, 0)
+      || __builtin_expect ((header->hash_offset
+			    + header->hash_size * sizeof (struct hash_entry))
+			   > cache_size, 0)
+      || __builtin_expect (header->module_offset >= cache_size, 0)
+      || __builtin_expect (header->otherconv_offset > cache_size, 0))
+    {
+      if (cache_malloced)
+	{
+	  free (cache);
+	  cache_malloced = 0;
+	}
+#ifdef _POSIX_MAPPED_FILES
+      else
+	munmap (cache, cache_size);
+#endif
+      cache = NULL;
+
+      return -1;
+    }
+
+  /* That worked.  */
+  return 0;
+}
+
+
+static int
+internal_function
+find_module_idx (const char *str, size_t *idxp)
+{
+  unsigned int idx;
+  unsigned int hval;
+  unsigned int hval2;
+  const struct gconvcache_header *header;
+  const char *strtab;
+  const struct hash_entry *hashtab;
+  unsigned int limit;
+
+  header = (const struct gconvcache_header *) cache;
+  strtab = (char *) cache + header->string_offset;
+  hashtab = (struct hash_entry *) ((char *) cache + header->hash_offset);
+
+  hval = hash_string (str);
+  idx = hval % header->hash_size;
+  hval2 = 1 + hval % (header->hash_size - 2);
+
+  limit = cache_size - header->string_offset;
+  while (hashtab[idx].string_offset != 0)
+    if (hashtab[idx].string_offset < limit
+	&& strcmp (str, strtab + hashtab[idx].string_offset) == 0)
+      {
+	*idxp = hashtab[idx].module_idx;
+	return 0;
+      }
+    else
+      if ((idx += hval2) >= header->hash_size)
+	idx -= header->hash_size;
+
+  /* Nothing found.  */
+  return -1;
+}
+
+
+static int
+internal_function
+find_module (const char *directory, const char *filename,
+	     struct __gconv_step *result)
+{
+  size_t dirlen = strlen (directory);
+  size_t fnamelen = strlen (filename) + 1;
+  char *fullname;
+  int status = __GCONV_OK;
+
+  fullname = (char *) malloc (dirlen + fnamelen);
+  if (fullname == NULL)
+    return __GCONV_NOMEM;
+
+  memcpy (__mempcpy (fullname, directory, dirlen), filename, fnamelen);
+
+  result->__shlib_handle = __gconv_find_shlib (fullname);
+  if (result->__shlib_handle == NULL)
+    return __GCONV_NOCONV;
+
+  result->__modname = fullname;
+  result->__fct = result->__shlib_handle->fct;
+  result->__init_fct = result->__shlib_handle->init_fct;
+  result->__end_fct = result->__shlib_handle->end_fct;
+  result->__counter = 1;
+
+  result->__data = NULL;
+  if (result->__init_fct != NULL)
+    status = DL_CALL_FCT (result->__init_fct, (result));
+
+  return status;
+}
+
+
+int
+internal_function
+__gconv_lookup_cache (const char *toset, const char *fromset,
+		      struct __gconv_step **handle, size_t *nsteps, int flags)
+{
+  const struct gconvcache_header *header;
+  const char *strtab;
+  size_t fromidx;
+  size_t toidx;
+  const struct module_entry *modtab;
+  const struct module_entry *from_module;
+  const struct module_entry *to_module;
+  struct __gconv_step *result;
+
+  if (cache == NULL)
+    /* We have no cache available.  */
+    return __GCONV_NODB;
+
+  header = (const struct gconvcache_header *) cache;
+  strtab = (char *) cache + header->string_offset;
+  modtab = (const struct module_entry *) ((char *) cache
+					  + header->module_offset);
+
+  if (find_module_idx (fromset, &fromidx) != 0
+      || (header->module_offset + (fromidx + 1) * sizeof (struct module_entry)
+	  > cache_size))
+    return __GCONV_NOCONV;
+  from_module = &modtab[fromidx];
+
+  if (find_module_idx (toset, &toidx) != 0
+      || (header->module_offset + (toidx + 1) * sizeof (struct module_entry)
+	  > cache_size))
+    return __GCONV_NOCONV;
+  to_module = &modtab[toidx];
+
+  /* Avoid copy-only transformations if the user requests.   */
+  if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) && fromidx == toidx)
+    return __GCONV_NOCONV;
+
+  /* If there are special conversions available examine them first.  */
+  if (__builtin_expect (from_module->extra_offset, 0) != 0)
+    {
+      /* Search through the list to see whether there is a module
+	 matching the destination character set.  */
+      const struct extra_entry *extra;
+
+      /* Note the -1.  This is due to the offset added in iconvconfig.
+	 See there for more explanations.  */
+      extra = (const struct extra_entry *) ((char *) cache
+					    + header->otherconv_offset
+					    + from_module->extra_offset - 1);
+      while (extra->module_cnt != 0
+	     && extra->module[extra->module_cnt - 1].outname_offset != toidx)
+	extra = (const struct extra_entry *) ((char *) extra
+					      + sizeof (struct extra_entry)
+					      + (extra->module_cnt
+						 * sizeof (struct extra_entry_module)));
+
+      if (extra->module_cnt != 0)
+	{
+	  /* Use the extra module.  First determine how many steps.  */
+	  char *fromname;
+	  int idx;
+
+	  *nsteps = extra->module_cnt;
+	  *handle = result =
+	    (struct __gconv_step *) malloc (extra->module_cnt
+					    * sizeof (struct __gconv_step));
+	  if (result == NULL)
+	    return __GCONV_NOMEM;
+
+	  fromname = (char *) strtab + from_module->canonname_offset;
+	  idx = 0;
+	  do
+	    {
+	      result[idx].__from_name = fromname;
+	      fromname = result[idx].__to_name =
+		(char *) strtab + modtab[extra->module[idx].outname_offset].canonname_offset;
+
+#ifndef STATIC_GCONV
+	      if (strtab[extra->module[idx].dir_offset] != '\0')
+		{
+		  /* Load the module, return handle for it.  */
+		  int res;
+
+		  res = find_module (strtab + extra->module[idx].dir_offset,
+				     strtab + extra->module[idx].name_offset,
+				     &result[idx]);
+		  if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+		    {
+		      /* Something went wrong.  */
+		      free (result);
+		      goto try_internal;
+		    }
+		}
+	      else
+#endif
+		/* It's a builtin transformation.  */
+		__gconv_get_builtin_trans (strtab
+					   + extra->module[idx].name_offset,
+					   &result[idx]);
+
+	    }
+	  while (++idx < extra->module_cnt);
+
+	  return __GCONV_OK;
+	}
+    }
+
+ try_internal:
+  /* See whether we can convert via the INTERNAL charset.  */
+  if (__builtin_expect (from_module->fromname_offset, 1) == 0
+      || __builtin_expect (to_module->toname_offset, 1) == 0)
+    /* Not possible.  Nothing we can do.  */
+    return __GCONV_NOCONV;
+
+  /* Use the two modules.  */
+  result = (struct __gconv_step *) malloc (2 * sizeof (struct __gconv_step));
+  if (result == NULL)
+    return __GCONV_NOMEM;
+
+  *handle = result;
+  *nsteps = 2;
+
+  /* Generate data structure for conversion to INTERNAL.  */
+  result[0].__from_name = (char *) strtab + from_module->canonname_offset;
+  result[0].__to_name = (char *) "INTERNAL";
+
+#ifndef STATIC_GCONV
+  if (strtab[from_module->fromdir_offset] != '\0')
+    {
+      /* Load the module, return handle for it.  */
+      int res = find_module (strtab + from_module->fromdir_offset,
+			     strtab + from_module->fromname_offset,
+			     &result[0]);
+      if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+	{
+	  /* Something went wrong.  */
+	  free (result);
+	  return res;
+	}
+    }
+  else
+#endif
+    /* It's a builtin transformation.  */
+    __gconv_get_builtin_trans (strtab + from_module->fromname_offset,
+			       &result[0]);
+
+  /* Generate data structure for conversion from INTERNAL.  */
+  result[1].__from_name = (char *) "INTERNAL";
+  result[1].__to_name = (char *) strtab + to_module->canonname_offset;
+
+#ifndef STATIC_GCONV
+  if (strtab[to_module->todir_offset] != '\0')
+    {
+      /* Load the module, return handle for it.  */
+      int res = find_module (strtab + to_module->todir_offset,
+			     strtab + to_module->toname_offset,
+			     &result[1]);
+      if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+	{
+	  /* Something went wrong.  */
+	  __gconv_release_step (&result[0]);
+	  free (result);
+	  return res;
+	}
+    }
+  else
+#endif
+    /* It's a builtin transformation.  */
+    __gconv_get_builtin_trans (strtab + to_module->toname_offset, &result[1]);
+
+  return __GCONV_OK;
+}
+
+
+/* Free all resources if necessary.  */
+static void __attribute__ ((unused))
+free_mem (void)
+{
+  if (cache_malloced)
+    free (cache);
+#ifdef _POSIX_MAPPED_FILES
+  else
+    munmap (cache, cache_size);
+#endif
+}
+
+text_set_element (__libc_subfreeres, free_mem);