Function plugin_dl_add

sql/sql_plugin.cc:744–887

#endif /* HAVE_DLOPEN */

static st_plugin_dl *plugin_dl_add(const LEX_CSTRING *dl, myf MyFlags)
{
#ifdef HAVE_DLOPEN
  char dlpath[FN_REFLEN];
  size_t plugin_dir_len,i;
  uint dummy_errors;
  struct st_plugin_dl *tmp= 0, plugin_dl;
  void *sym;
  st_ptr_backup tmp_backup[array_elements(list_of_services)];
  DBUG_ENTER("plugin_dl_add");
  DBUG_PRINT("enter", ("dl->str: '%s', dl->length: %d",
                       dl->str, (int) dl->length));
  mysql_mutex_assert_owner(&LOCK_plugin);
  plugin_dir_len= strlen(opt_plugin_dir);
  /*
    Ensure that the dll doesn't have a path.
    This is done to ensure that only approved libraries from the
    plugin directory are used (to make this even remotely secure).
  */
  if (check_string_char_length((LEX_CSTRING *) dl, 0, NAME_CHAR_LEN,
                               system_charset_info, 1) ||
      check_valid_path(dl->str, dl->length) ||
      plugin_dir_len + dl->length + 1 >= FN_REFLEN)
  {
    my_error(ER_UDF_NO_PATHS, MyFlags);
    DBUG_RETURN(0);
  }
  /* If this dll is already loaded just increase ref_count. */
  if ((tmp= plugin_dl_find(dl)))
  {
    tmp->ref_count++;
    DBUG_RETURN(tmp);
  }
  bzero(&plugin_dl, sizeof(plugin_dl));
  /* Compile dll path */
  strxnmov(dlpath, sizeof(dlpath) - 1, opt_plugin_dir, "/", dl->str, NullS);
  (void) unpack_filename(dlpath, dlpath);
  plugin_dl.ref_count= 1;
  /* Open new dll handle */
  if (!(plugin_dl.handle= dlopen(dlpath, RTLD_NOW)))
  {
    if (!opt_silent_startup)
      my_error(ER_CANT_OPEN_LIBRARY, MyFlags, dlpath, errno,
               my_dlerror(dlpath));
    goto ret;
  }
  dlopen_count++;

#ifdef HAVE_LINK_H
  if (global_system_variables.log_warnings > 2)
  {
    struct link_map *lm = (struct link_map*) plugin_dl.handle;
    sql_print_information("Loaded '%s' with offset 0x%zx", dl->str, (size_t)lm->l_addr);
  }
#endif

  /* Checks which plugin interface present and reads info */
  if (!(sym= dlsym(plugin_dl.handle, maria_plugin_interface_version_sym)))