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Sourcecode: wireshark version File versions

plugins.c

/* plugins.c
 * plugin routines
 *
 * $Id: plugins.c 18310 2006-06-02 06:50:57Z jmayer $
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1999 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "plugins.h"

#ifdef HAVE_PLUGINS

#include <time.h>

#ifdef HAVE_DIRENT_H
#include <dirent.h>
#endif

#ifdef HAVE_DIRECT_H
#include <direct.h>
#endif

#include <string.h>
#include <stdlib.h>
#include <errno.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "filesystem.h"
#include "privileges.h"
#include <wiretap/file_util.h>
#include "report_err.h"

/* linked list of all plugins */
plugin *plugin_list;

#define PLUGINS_DIR_NAME      "plugins"

/*
 * add a new plugin to the list
 * returns :
 * - 0 : OK
 * - ENOMEM : memory allocation problem
 * - EEXIST : the same plugin (i.e. name/version) was already registered.
 */
static int
add_plugin(void *handle, gchar *name, gchar *version,
         void (*register_protoinfo)(void), void (*reg_handoff)(void),
         void (*register_tap_listener)(void))
{
    plugin *new_plug, *pt_plug;

    pt_plug = plugin_list;
    if (!pt_plug) /* the list is empty */
    {
      new_plug = (plugin *)g_malloc(sizeof(plugin));
      if (new_plug == NULL) return ENOMEM;
        plugin_list = new_plug;
    }
    else
    {
      while (1)
      {
          /* check if the same name/version is already registered */
          if (!strcmp(pt_plug->name, name) &&
            !strcmp(pt_plug->version, version))
          {
            return EEXIST;
          }

          /* we found the last plugin in the list */
          if (pt_plug->next == NULL) break;

          pt_plug = pt_plug->next;
      }
      new_plug = (plugin *)g_malloc(sizeof(plugin));
      if (new_plug == NULL) return ENOMEM;
      pt_plug->next = new_plug;
    }

    new_plug->handle = handle;
    new_plug->name = name;
    new_plug->version = version;
    new_plug->register_protoinfo = register_protoinfo;
    new_plug->reg_handoff = reg_handoff;
    new_plug->register_tap_listener = register_tap_listener;
    new_plug->next = NULL;
    return 0;
}

/*
 * XXX - when we remove support for old-style plugins (which we should
 * probably do eventually, as all plugins should be written as new-style
 * ones), we may want to have "init_plugins()" merely save a pointer
 * to the plugin's "init" routine, just as we save a pointer to its
 * "reg_handoff" routine, and have a "register_all_plugins()" routine
 * to go through the list of plugins and call all of them.
 *
 * Then we'd have "epan_init()", or perhaps even something higher up
 * in the call tree, call "init_plugins()", and have "proto_init()"
 * call "register_all_plugins()" right after calling "register_all_protocols()";
 * this might be a bit cleaner.
 */
static void
plugins_scan_dir(const char *dirname)
{
#define FILENAME_LEN    1024
    ETH_DIR       *dir;             /* scanned directory */
    ETH_DIRENT    *file;            /* current file */
    const char    *name;
#if GLIB_MAJOR_VERSION < 2
    gchar         *hack_path;       /* pathname used to construct lt_lib_ext */
    gchar         *lt_lib_ext;      /* extension for loadable modules */
#endif
    gchar          filename[FILENAME_LEN];   /* current file name */
    GModule       *handle;          /* handle returned by dlopen */
    gchar         *version;
    gpointer       gp;
    void         (*register_protoinfo)(void);
    void         (*reg_handoff)(void);
    void         (*register_tap_listener)(void);
    gchar         *dot;
    int            cr;

#if GLIB_MAJOR_VERSION < 2
    /*
     * We find the extension used on this platform for loadable modules
     * by the sneaky hack of calling "g_module_build_path" to build
     * the pathname for a module with an empty directory name and
     * empty module name, and then search for the last "." and use
     * everything from the last "." on.
     */
    hack_path = g_module_build_path("", "");
    lt_lib_ext = strrchr(hack_path, '.');
    if (lt_lib_ext == NULL)
    {
      /*
       * Does this mean there *is* no extension?  Assume so.
       *
       * XXX - the code below assumes that all loadable modules have
       * an extension....
       */
      lt_lib_ext = "";
    }
#endif

    if ((dir = eth_dir_open(dirname, 0, NULL)) != NULL)
    {
    while ((file = eth_dir_read_name(dir)) != NULL)
      {
          name = eth_dir_get_name(file);
#if GLIB_MAJOR_VERSION < 2
          /* don't try to open "." and ".." */
          if (!(strcmp(name, "..") &&
              strcmp(name, "."))) continue;

            /* skip anything but files with lt_lib_ext */
            dot = strrchr(name, '.');
            if (dot == NULL || strcmp(dot, lt_lib_ext) != 0) continue;

#else /* GLIB 2 */
    /*
     * GLib 2.x defines G_MODULE_SUFFIX as the extension used on this
     * platform for loadable modules.
     */
          /* skip anything but files with G_MODULE_SUFFIX */
            dot = strrchr(name, '.');
            if (dot == NULL || strcmp(dot+1, G_MODULE_SUFFIX) != 0) continue;

#endif
          g_snprintf(filename, FILENAME_LEN, "%s" G_DIR_SEPARATOR_S "%s",
              dirname, name);
          if ((handle = g_module_open(filename, 0)) == NULL)
          {
            report_failure("Couldn't load module %s: %s", filename,
                    g_module_error());
            continue;
          }
          if (!g_module_symbol(handle, "version", &gp))
          {
              report_failure("The plugin %s has no version symbol", name);
            g_module_close(handle);
            continue;
          }
          version = gp;
          
          /*
           * Do we have a register routine?
           */
          if (g_module_symbol(handle, "plugin_register", &gp))
          {
            /*
             * Yes - this plugin includes one or more dissectors.
             */
            register_protoinfo = gp;
          }
          else
          {
            /*
             * No - no dissectors.
             */
            register_protoinfo = NULL;
          }

          /*
           * Do we have a reg_handoff routine?
           */
          if (g_module_symbol(handle, "plugin_reg_handoff", &gp))
          {
            /*
             * Yes.
             */
            reg_handoff = gp;
          }
          else
          {
            /*
             * No - that's OK even if we have dissectors, as long
             * as the plugin registers by name *and* there's
             * a caller looking for that name.
             */
            reg_handoff = NULL;
          }

          /*
           * Do we have a register_tap_listener routine?
           */
          if (g_module_symbol(handle, "plugin_register_tap_listener", &gp))
          {
            /*
             * Yes - this plugin includes one or more taps.
             */
            register_tap_listener = gp;
          }
          else
          {
            /*
             * No - no taps here.
             */
            register_tap_listener = NULL;
          }

          /*
           * Do we have an old-style init routine?
           */
          if (g_module_symbol(handle, "plugin_init", &gp))
          {
            /*
             * Yes - do we also have a register routine or a
             * register_tap_listener routine?  If so, this is a bogus
             * hybrid of an old-style and new-style plugin.
             */
            if (register_protoinfo != NULL || register_tap_listener != NULL)
            {
                report_failure("The plugin %s has an old plugin init routine\nand a new register or register_tap_listener routine.",
                  name);
                g_module_close(handle);
                continue;
            }

            /*
             * It's just an unsupported old-style plugin;
             */
            report_failure("The plugin %s has an old plugin init routine. Support has been dropped.\n Information on how to update your plugin is available at \nhttp://anonsvn.wireshark.org/wireshark/trunk/doc/README.plugins",
                name);
            g_module_close(handle);
            continue;
          }

          /*
           * Does this dissector do anything useful?
           */
          if (register_protoinfo == NULL &&
            register_tap_listener == NULL)
          {
            /*
             * No.
             */
            report_failure("The plugin %s has neither a register routine, or a register_tap_listener routine",
                name);
            g_module_close(handle);
            continue;
          }

          /*
           * OK, attempt to add it to the list of plugins.
           */
          if ((cr = add_plugin(handle, g_strdup(name), version,
                         register_protoinfo, reg_handoff,
                         register_tap_listener)))
          {
            if (cr == EEXIST)
                fprintf(stderr, "The plugin %s, version %s\n"
                      "was found in multiple directories\n", name, version);
            else
                fprintf(stderr, "Memory allocation problem\n"
                      "when processing plugin %s, version %s\n",
                      name, version);
            g_module_close(handle);
            continue;
          }

          /*
           * Call its register routine if it has one.
           * XXX - just save this and call it with the built-in
           * dissector register routines?
           */
          if (register_protoinfo != NULL)
                register_protoinfo();

      }
      eth_dir_close(dir);
      }
#if GLIB_MAJOR_VERSION < 2
    g_free(hack_path);
#endif
}


/* get the global plugin dir */
/* Return value is malloced so the caller should g_free() it. */
char *get_plugins_global_dir(const char *plugin_dir)
{
#ifdef _WIN32
      char *install_plugin_dir;

      /*
       * On Windows, the data file directory is the installation
       * directory; the plugins are stored under it.
       *
       * Assume we're running the installed version of Wireshark;
       * on Windows, the data file directory is the directory
       * in which the Wireshark binary resides.
       */
      install_plugin_dir = g_strdup_printf("%s\\plugins\\%s", get_datafile_dir(), VERSION);

      /*
       * Make sure that pathname refers to a directory.
       */
      if (test_for_directory(install_plugin_dir) != EISDIR) {
            /*
             * Either it doesn't refer to a directory or it
             * refers to something that doesn't exist.
             *
             * Assume that means we're running, for example,
             * a version of Wireshark we've built in a source
             * directory, and fall back on the default
             * installation directory, so you can put the plugins
             * somewhere so they can be used with this version
             * of Wireshark.
             *
             * XXX - should we, instead, have the Windows build
             * procedure create a subdirectory of the "plugins"
             * source directory, and copy the plugin DLLs there,
             * so that you use the plugins from the build tree?
             */
            g_free(install_plugin_dir);
            install_plugin_dir =
                g_strdup("C:\\Program Files\\Wireshark\\plugins\\" VERSION);
      }

      return install_plugin_dir;
#else
      /*
       * Scan the plugin directory.
       */
      return g_strdup(plugin_dir);
#endif
}


/* get the personal plugin dir */
/* Return value is malloced so the caller should g_free() it. */
char *get_plugins_pers_dir(void)
{
    return get_persconffile_path(PLUGINS_DIR_NAME, FALSE);
}

/*
 * init plugins
 */
void
init_plugins(const char *plugin_dir)
{
    char *datafile_dir;

    if (plugin_list == NULL)      /* ensure init_plugins is only run once */
    {
      /*
       * Scan the global plugin directory.
       */
      datafile_dir = get_plugins_global_dir(plugin_dir);
      plugins_scan_dir(datafile_dir);
      g_free(datafile_dir);

      /*
       * If the program wasn't started with special privileges,
       * scan the users plugin directory.  (Even if we relinquish
       * them, plugins aren't safe unless we've *permanently*
       * relinquished them, and we can't do that in Wireshark as,
       * if we need privileges to start capturing, we'd need to
       * reclaim them before each time we start capturing.)
       */
      if (!started_with_special_privs()) {
          datafile_dir = get_plugins_pers_dir();
          plugins_scan_dir(datafile_dir);
          g_free(datafile_dir);
      }
    }
}

void
register_all_plugin_handoffs(void)
{
    plugin *pt_plug;

    /*
     * For all plugins with register-handoff routines, call the routines.
     * This is called from "proto_init()"; it must be called after
     * "register_all_protocols()" and "init_plugins()" are called,
     * in case one plugin registers itself either with a built-in
     * dissector or with another plugin; we must first register all
     * dissectors, whether built-in or plugin, so their dissector tables
     * are initialized, and only then register all handoffs.
     */
    for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
    {
      if (pt_plug->reg_handoff)
          (pt_plug->reg_handoff)();
    }
}

void
register_all_plugin_tap_listeners(void)
{
    plugin *pt_plug;

    /*
     * For all plugins with register-tap-listener routines, call the
     * routines.
     */
    for (pt_plug = plugin_list; pt_plug != NULL; pt_plug = pt_plug->next)
    {
      if (pt_plug->register_tap_listener)
          (pt_plug->register_tap_listener)();
    }
}
#endif

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