wiretap/wtap-plugins.c

   1 /* wtap.h
   2 *
   3 * $Id: wtap.h 21651 2007-05-02 20:09:42Z lego $
   4 *
   5 * Wiretap Library
   6 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * as published by the Free Software Foundation; either version 2
  11 * of the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  21 */
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <glib.h>
  28 #include <gmodule.h>
  29
  30 #ifdef HAVE_DIRENT_H
  31 #include <dirent.h>
  32 #endif
  33
  34 #ifdef HAVE_DIRECT_H
  35 #include <direct.h>
  36 #endif
  37
  38 #include <string.h>
  39 #include <stdlib.h>
  40 #include <errno.h>
  41
  42 #ifdef HAVE_UNISTD_H
  43 #include <unistd.h>
  44 #endif
  45
  46 #include "wtap.h"
  47 #include "file_util.h"
  48
  49 #define PLUGINS_DIR_NAME        "wiretap_plugins"
  50
  51 static gboolean plugins_loaded = FALSE;
  52
  53 void wtap_load_plugins(char* dirname) {
  54
  55 #define FILENAME_LEN    1024
  56                 ETH_DIR       *dir;             /* scanned directory */
  57                 ETH_DIRENT    *file;            /* current file */
  58                 const char    *name;
  59 #if GLIB_MAJOR_VERSION < 2
  60                 gchar         *hack_path;       /* pathname used to construct lt_lib_ext */
  61                 gchar         *lt_lib_ext;      /* extension for loadable modules */
  62 #endif
  63                 gchar          filename[FILENAME_LEN];   /* current file name */
  64                 GModule       *handle;          /* handle returned by dlopen */
  65                 gchar         *version;
  66                 gpointer       gp;
  67                 gchar         *dot;
  68
  69                 if (plugins_loaded || ! dirname) return;
  70
  71                 plugins_loaded = TRUE;
  72
  73 #if GLIB_MAJOR_VERSION < 2
  74                 /*
  75                  * We find the extension used on this platform for loadable modules
  76                  * by the sneaky hack of calling "g_module_build_path" to build
  77                  * the pathname for a module with an empty directory name and
  78                  * empty module name, and then search for the last "." and use
  79                  * everything from the last "." on.
  80                  */
  81                 hack_path = g_module_build_path("", "");
  82                 lt_lib_ext = strrchr(hack_path, '.');
  83                 if (lt_lib_ext == NULL)
  84                 {
  85                         /*
  86                          * Does this mean there *is* no extension?  Assume so.
  87                          *
  88                          * XXX - the code below assumes that all loadable modules have
  89                          * an extension....
  90                          */
  91                         lt_lib_ext = "";
  92                 }
  93 #endif
  94
  95                 if ((dir = eth_dir_open(dirname, 0, NULL)) != NULL)
  96                 {
  97                         while ((file = eth_dir_read_name(dir)) != NULL)
  98                         {
  99                                 name = eth_dir_get_name(file);
 100 #if GLIB_MAJOR_VERSION < 2
 101                                 /* don't try to open "." and ".." */
 102                                 if (!(strcmp(name, "..") &&
 103                                           strcmp(name, ".")))
 104                                         continue;
 105
 106                                 /* skip anything but files with lt_lib_ext */
 107                                 dot = strrchr(name, '.');
 108                                 if (dot == NULL || strcmp(dot, lt_lib_ext) != 0)
 109                                         continue;
 110
 111 #else /* GLIB 2 */
 112                                 /*
 113                                  * GLib 2.x defines G_MODULE_SUFFIX as the extension used on
 114                                  * this platform for loadable modules.
 115                                  */
 116                                 /* skip anything but files with G_MODULE_SUFFIX */
 117                                 dot = strrchr(name, '.');
 118                                 if (dot == NULL || strcmp(dot+1, G_MODULE_SUFFIX) != 0)
 119                                         continue;
 120
 121 #endif
 122                                 g_snprintf(filename, FILENAME_LEN, "%s" G_DIR_SEPARATOR_S "%s",
 123                                                    dirname, name);
 124                                 if ((handle = g_module_open(filename, 0)) == NULL)
 125                                 {
 126                                         g_warning("Couldn't load module %s: %s", filename,
 127                                                                    g_module_error());
 128                                         continue;
 129                                 }
 130                                 if (!g_module_symbol(handle, "version", &gp))
 131                                 {
 132                                         g_warning("The plugin %s has no version symbol", name);
 133                                         g_module_close(handle);
 134                                         continue;
 135                                 }
 136                                 version = gp;
 137
 138                                 if (g_module_symbol(handle, "register_wtap_module", &gp))
 139                                 {
 140                                         void (*register_wtap_module)(void) = gp;
 141                                         register_wtap_module();
 142                                 }
 143                         }
 144                         eth_dir_close(dir);
 145                 }
 146 #if GLIB_MAJOR_VERSION < 2
 147                 g_free(hack_path);
 148                 g_free(dirname);
 149 #endif
 150
 151 }
 152