plugins support (i.e. Dynamically loadable dissectors)

depends on dlopen() being available on the target platform

svn path=/trunk/; revision=1263

12 files changed, 747 insertions, 13 deletions

diff --git a/Makefile.am b/Makefile.am
index b596543f8e..c387bfa84f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for Ethereal
 #
-# $Id: Makefile.am,v 1.130 1999/12/09 07:19:01 guy Exp $
+# $Id: Makefile.am,v 1.131 1999/12/09 20:41:23 oabad Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@zing.org>
@@ -186,6 +186,8 @@ ethereal_SOURCES = \
 	ipv4.h         \
 	packet.c       \
 	packet.h       \
+	plugins.c      \
+	plugins.h      \
 	prefs.c        \
 	prefs.h        \
 	print.c        \
diff --git a/configure.in b/configure.in
index 62f1cfafb7..99d7bf3665 100644
--- a/configure.in
+++ b/configure.in
@@ -1,4 +1,4 @@
-# $Id: configure.in,v 1.63 1999/12/05 02:32:40 guy Exp $
+# $Id: configure.in,v 1.64 1999/12/09 20:41:23 oabad Exp $
 dnl
 dnl Process this file with autoconf 2.13 or later to produce a
 dnl configure script; 2.12 doesn't generate a "configure" script that
@@ -142,6 +142,7 @@ AC_CHECK_HEADERS(fcntl.h sys/ioctl.h sys/time.h unistd.h stdarg.h netdb.h)
 AC_CHECK_HEADERS(sys/stat.h sys/sockio.h sys/types.h netinet/in.h sys/socket.h net/if.h)
 AC_CHECK_HEADERS(sys/wait.h)
 AC_CHECK_HEADERS(stddef.h)
+AC_CHECK_HEADERS(dlfcn.h)
 
 dnl SNMP Check
 AC_ARG_ENABLE(snmp,
diff --git a/file.c b/file.c
index bc84dc6d32..81b0efa712 100644
--- a/file.c
+++ b/file.c
@@ -1,7 +1,7 @@
 /* file.c
  * File I/O routines
  *
- * $Id: file.c,v 1.135 1999/12/09 07:19:03 guy Exp $
+ * $Id: file.c,v 1.136 1999/12/09 20:41:24 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -83,6 +83,10 @@
 #include "conversation.h"
 #include "globals.h"
 
+#ifdef HAVE_DLFCN_H
+#include "plugins.h"
+#endif
+
 #ifndef __RESOLV_H__
 #include "resolv.h"
 #endif
@@ -777,7 +781,7 @@ add_packet_to_packet_list(frame_data *fdata, capture_file *cf, const u_char *buf
   gint          i, row;
   gint		crow;
   gint 		color;
-  proto_tree   *protocol_tree;
+  proto_tree   *protocol_tree = NULL;
 
   fdata->num = cf->count;
 
@@ -829,9 +833,17 @@ add_packet_to_packet_list(frame_data *fdata, capture_file *cf, const u_char *buf
 	proto_tree_free(protocol_tree);
   }
   else {
-	dissect_packet(buf, fdata, NULL);
+#ifdef HAVE_DLFCN_H
+	if (plugin_list)
+	    protocol_tree = proto_tree_create_root();
+#endif
+	dissect_packet(buf, fdata, protocol_tree);
 	fdata->passed_dfilter = TRUE;
 	color = -1;
+#ifdef HAVE_DLFCN_H
+	if (protocol_tree)
+	    proto_tree_free(protocol_tree);
+#endif
   }
   if (fdata->passed_dfilter) {
     /* If we don't have the time stamp of the previous displayed packet,
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 434ece6bbf..22db238862 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for the GTK interface routines for Ethereal
 #
-# $Id: Makefile.am,v 1.13 1999/12/09 07:19:16 guy Exp $
+# $Id: Makefile.am,v 1.14 1999/12/09 20:41:40 oabad Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@zing.org>
@@ -48,6 +48,7 @@ libui_a_SOURCES = \
 	main.h		\
 	menu.c		\
 	menu.h		\
+	plugins_dlg.c	\
 	prefs_dlg.c	\
 	prefs_dlg.h	\
 	print_dlg.c	\
diff --git a/gtk/keys.h b/gtk/keys.h
index 0b73c4e2e1..53e7d60996 100644
--- a/gtk/keys.h
+++ b/gtk/keys.h
@@ -1,7 +1,7 @@
 /* keys.h
  * Key definitions for various objects
  *
- * $Id: keys.h,v 1.7 1999/11/25 18:02:24 gerald Exp $
+ * $Id: keys.h,v 1.8 1999/12/09 20:41:41 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -39,4 +39,6 @@
 #define PRINT_FILE_TE_KEY         "printer_file_entry"
 #define PRINT_DEST_RB_KEY         "printer_destination_radio_button"
 
+#define PLUGINS_DFILTER_TE        "plugins_dfilter_te"
+
 #endif
diff --git a/gtk/main.h b/gtk/main.h
index 8f25fcb9ba..91cc1e04e3 100644
--- a/gtk/main.h
+++ b/gtk/main.h
@@ -1,7 +1,7 @@
 /* ethereal.h
  * Global defines, etc.
  *
- * $Id: main.h,v 1.6 1999/10/08 07:29:42 guy Exp $
+ * $Id: main.h,v 1.7 1999/12/09 20:41:41 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -64,6 +64,9 @@ void file_quit_cmd_cb(GtkWidget *, gpointer);
 void file_reload_cmd_cb(GtkWidget *, gpointer);
 void file_print_cmd_cb(GtkWidget *, gpointer);
 void file_print_packet_cmd_cb(GtkWidget *, gpointer);
+#ifdef HAVE_DLFCN_H
+void tools_plugins_cmd_cb(GtkWidget *, gpointer);
+#endif
 void expand_all_cb(GtkWidget *, gpointer);
 void collapse_all_cb(GtkWidget *, gpointer);
 
diff --git a/gtk/menu.c b/gtk/menu.c
index a8250556c5..8cf4aac083 100644
--- a/gtk/menu.c
+++ b/gtk/menu.c
@@ -1,7 +1,7 @@
 /* menu.c
  * Menu routines
  *
- * $Id: menu.c,v 1.8 1999/12/05 23:44:24 guy Exp $
+ * $Id: menu.c,v 1.9 1999/12/09 20:41:41 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -108,6 +108,9 @@ static GtkItemFactoryEntry menu_items[] =
   {"/Display/Collapse _All", NULL, GTK_MENU_FUNC(collapse_all_cb), 0, NULL},
   {"/Display/_Expand All", NULL, GTK_MENU_FUNC(expand_all_cb), 0, NULL},
   {"/_Tools", NULL, NULL, 0, "<Branch>" },
+#ifdef HAVE_DLFCN_H
+  {"/Tools/_Plugins...", NULL, GTK_MENU_FUNC(tools_plugins_cmd_cb), 0, NULL},
+#endif
   {"/Tools/_Follow TCP Stream", NULL, GTK_MENU_FUNC(follow_stream_cb), 0, NULL},
 /*  {"/Tools/Graph", NULL, NULL, 0, NULL}, future use */
   {"/Tools/_Summary", NULL, GTK_MENU_FUNC(summary_prep_cb), 0, NULL},
diff --git a/gtk/plugins_dlg.c b/gtk/plugins_dlg.c
new file mode 100644
index 0000000000..759b8647da
--- /dev/null
+++ b/gtk/plugins_dlg.c
@@ -0,0 +1,412 @@
+/* plugins_dlg.c
+ * Dialog boxes for plugins
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 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
+
+#ifdef HAVE_DLFCN_H
+
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+
+#include "globals.h"
+#include "plugins.h"
+#include "keys.h"
+#include "prefs_dlg.h"
+#include "ui_util.h"
+
+static gint selected_row;
+static gchar *selected_name;
+static gchar *selected_version;
+static gchar *selected_enabled;
+static gchar std_plug_dir[] = "/usr/share/ethereal/plugins";
+static gchar local_plug_dir[] = "/usr/local/share/ethereal/plugins";
+static gchar *user_plug_dir = NULL;
+
+static void plugins_close_cb(GtkWidget *, gpointer);
+static void plugins_scan(GtkWidget *);
+static void plugins_scan_dir(const char *);
+static void plugins_clist_select_cb(GtkWidget *, gint, gint,
+	GdkEventButton *, gpointer);
+static void plugins_clist_unselect_cb(GtkWidget *, gint, gint,
+	GdkEventButton *, gpointer);
+static void plugins_enable_cb(GtkWidget *, gpointer);
+static void plugins_disable_cb(GtkWidget *, gpointer);
+static void plugins_filter_cb(GtkWidget *, gpointer);
+static void filter_ok_cb(GtkWidget *, gpointer);
+static void filter_cancel_cb(GtkWidget *, gpointer);
+
+void
+tools_plugins_cmd_cb(GtkWidget *widget, gpointer data)
+{
+    GtkWidget *plugins_window;
+    GtkWidget *main_vbox;
+    GtkWidget *main_frame;
+    GtkWidget *frame_hbox;
+    GtkWidget *scrolledwindow;
+    GtkWidget *plugins_clist;
+    GtkWidget *frame_vbnbox;
+    GtkWidget *enable_bn;
+    GtkWidget *disable_bn;
+    GtkWidget *filter_bn;
+    GtkWidget *main_hbnbox;
+    GtkWidget *close_bn;
+    gchar     *titles[] = {"Name", "Description", "Version", "Enabled"};
+
+    plugins_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+    gtk_window_set_title(GTK_WINDOW(plugins_window), "Ethereal: Plugins");
+
+    main_vbox = gtk_vbox_new(FALSE, 0);
+    gtk_container_add(GTK_CONTAINER(plugins_window), main_vbox);
+    gtk_widget_show(main_vbox);
+
+    main_frame = gtk_frame_new("Plugins List");
+    gtk_box_pack_start(GTK_BOX(main_vbox), main_frame, TRUE, TRUE, 0);
+    gtk_container_set_border_width(GTK_CONTAINER(main_frame), 10);
+    gtk_widget_show(main_frame);
+
+    frame_hbox = gtk_hbox_new(FALSE,0);
+    gtk_container_add(GTK_CONTAINER(main_frame), frame_hbox);
+    gtk_container_set_border_width(GTK_CONTAINER(frame_hbox), 5);
+    gtk_widget_show(frame_hbox);
+
+    scrolledwindow = gtk_scrolled_window_new(NULL, NULL);
+    gtk_box_pack_start(GTK_BOX(frame_hbox), scrolledwindow, TRUE, TRUE, 0);
+    gtk_widget_set_usize(scrolledwindow, 400, 150);
+    gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrolledwindow),
+	    GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
+    gtk_widget_show(scrolledwindow);
+
+    plugins_clist = gtk_clist_new_with_titles(4, titles);
+    gtk_container_add(GTK_CONTAINER(scrolledwindow), plugins_clist);
+    gtk_clist_set_selection_mode(GTK_CLIST(plugins_clist), GTK_SELECTION_SINGLE);
+    gtk_clist_column_titles_passive(GTK_CLIST(plugins_clist));
+    gtk_clist_column_titles_show(GTK_CLIST(plugins_clist));
+    gtk_clist_set_column_auto_resize(GTK_CLIST(plugins_clist), 0, TRUE);
+    gtk_clist_set_column_auto_resize(GTK_CLIST(plugins_clist), 1, TRUE);
+    gtk_clist_set_column_auto_resize(GTK_CLIST(plugins_clist), 2, TRUE);
+    gtk_clist_set_column_auto_resize(GTK_CLIST(plugins_clist), 3, TRUE);
+    plugins_scan(plugins_clist);
+    gtk_signal_connect(GTK_OBJECT(plugins_clist), "select_row",
+	    GTK_SIGNAL_FUNC(plugins_clist_select_cb), NULL);
+    gtk_signal_connect(GTK_OBJECT(plugins_clist), "unselect_row",
+	    GTK_SIGNAL_FUNC(plugins_clist_unselect_cb), NULL);
+    gtk_widget_show(plugins_clist);
+    selected_row = -1;
+
+    frame_vbnbox = gtk_vbutton_box_new();
+    gtk_box_pack_start(GTK_BOX(frame_hbox), frame_vbnbox, FALSE, TRUE, 0);
+    gtk_container_set_border_width(GTK_CONTAINER(frame_vbnbox), 20);
+    gtk_button_box_set_layout(GTK_BUTTON_BOX(frame_vbnbox), GTK_BUTTONBOX_START);
+    gtk_widget_show(frame_vbnbox);
+
+    enable_bn = gtk_button_new_with_label("Enable");
+    gtk_container_add(GTK_CONTAINER(frame_vbnbox), enable_bn);
+    gtk_signal_connect(GTK_OBJECT(enable_bn), "clicked",
+	    GTK_SIGNAL_FUNC(plugins_enable_cb), GTK_OBJECT(plugins_clist));
+    gtk_widget_show(enable_bn);
+    disable_bn = gtk_button_new_with_label("Disable");
+    gtk_container_add(GTK_CONTAINER(frame_vbnbox), disable_bn);
+    gtk_signal_connect(GTK_OBJECT(disable_bn), "clicked",
+	    GTK_SIGNAL_FUNC(plugins_disable_cb), GTK_OBJECT(plugins_clist));
+    gtk_widget_show(disable_bn);
+    filter_bn = gtk_button_new_with_label("Filter");
+    gtk_container_add(GTK_CONTAINER(frame_vbnbox), filter_bn);
+    gtk_signal_connect(GTK_OBJECT(filter_bn), "clicked",
+	    GTK_SIGNAL_FUNC(plugins_filter_cb), GTK_OBJECT(plugins_clist));
+    gtk_widget_show(filter_bn);
+
+    main_hbnbox = gtk_hbutton_box_new();
+    gtk_box_pack_start(GTK_BOX(main_vbox), main_hbnbox, FALSE, TRUE, 0);
+    gtk_container_set_border_width(GTK_CONTAINER(main_hbnbox), 10);
+    gtk_widget_show(main_hbnbox);
+
+    close_bn = gtk_button_new_with_label("Close");
+    gtk_container_add(GTK_CONTAINER(main_hbnbox), close_bn);
+    gtk_widget_show(close_bn);
+    gtk_signal_connect(GTK_OBJECT(close_bn), "clicked",
+	    GTK_SIGNAL_FUNC(plugins_close_cb), GTK_OBJECT(plugins_window));
+
+    gtk_widget_show(plugins_window);
+}
+
+/*
+ * scan /usr/share/ethereal/plugins, /usr/local/share/ethereal/plugins and
+ * ~/.ethereal/plugins and fill the clist widget
+ */
+static void
+plugins_scan(GtkWidget *clist)
+{
+    plugin *pt_plug;
+    gchar  *plugent[4];               /* new entry added in clist */
+
+    if (plugin_list == NULL)          /* first intialisation */
+    {
+	plugins_scan_dir(std_plug_dir);
+	plugins_scan_dir(local_plug_dir);
+	if (!user_plug_dir)
+	{
+	    user_plug_dir = (gchar *)g_malloc(strlen(getenv("HOME")) + 19);
+	    sprintf(user_plug_dir, "%s/.ethereal/plugins", getenv("HOME"));
+	}
+	plugins_scan_dir(user_plug_dir);
+    }
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	plugent[0] = pt_plug->name;
+	plugent[1] = (gchar *)dlsym(pt_plug->handle, "desc");
+	plugent[2] = pt_plug->version;
+	plugent[3] = (pt_plug->enabled ? "Yes" : "No");
+	gtk_clist_append(GTK_CLIST(clist), plugent);
+	pt_plug = pt_plug->next;
+    }
+}
+
+static void
+plugins_scan_dir(const char *dirname)
+{
+    DIR           *dir;             /* scanned directory */
+    struct dirent *file;            /* current file */
+    gchar          filename[512];   /* current file name */
+    void          *handle;          /* handle returned by dlopen */
+    gchar         *name;
+    gchar         *version;
+    gchar         *protocol;
+    gchar         *filter_string;
+    dfilter       *filter = NULL;
+    void         (*dissector) (const u_char *, int, frame_data *, proto_tree *);
+    int            cr;
+
+    if ((dir = opendir(dirname)) != NULL)
+    {
+	while ((file = readdir(dir)) != NULL)
+	{
+	    sprintf(filename, "%s/%s", dirname, file->d_name);
+
+	    if ((handle = dlopen(filename, RTLD_LAZY)) == NULL) continue;
+	    name = (gchar *)file->d_name;
+	    if ((version = (gchar *)dlsym(handle, "version")) == NULL)
+	    {
+		dlclose(handle);
+		continue;
+	    }
+	    if ((protocol = (gchar *)dlsym(handle, "protocol")) == NULL)
+	    {
+		dlclose(handle);
+		continue;
+	    }
+	    if ((filter_string = (gchar *)dlsym(handle, "filter_string")) == NULL)
+	    {
+		dlclose(handle);
+		continue;
+	    }
+	    if (dfilter_compile(filter_string, &filter) != 0) {
+		dlclose(handle);
+		continue;
+	    }
+	    if ((dissector = (void (*)(const u_char *, int,
+				frame_data *,
+				proto_tree *)) dlsym(handle, "dissector")) == NULL)
+	    {
+		if (filter != NULL)
+		    dfilter_destroy(filter);
+		dlclose(handle);
+		continue;
+	    }
+
+	    if ((cr = add_plugin(handle, g_strdup(file->d_name), version,
+				 protocol, filter_string, filter, dissector)))
+	    {
+		if (cr == EEXIST)
+		    simple_dialog(ESD_TYPE_WARN, NULL, "The plugin : %s, version %s\n"
+			"was found in multiple directories", name, version);
+		else
+		    simple_dialog(ESD_TYPE_WARN, NULL, "Memory allocation problem");
+		if (filter != NULL)
+		    dfilter_destroy(filter);
+		dlclose(handle);
+		continue;
+	    }
+	}
+	closedir(dir);
+    }
+}
+
+static void
+plugins_close_cb(GtkWidget *close_bt, gpointer parent_w)
+{
+    gtk_grab_remove(GTK_WIDGET(parent_w));
+    gtk_widget_destroy(GTK_WIDGET(parent_w));
+}
+
+void plugins_clist_select_cb(GtkWidget *clist, gint row, gint column,
+	GdkEventButton *event, gpointer data)
+{
+    selected_row = row;
+    gtk_clist_get_text(GTK_CLIST(clist), selected_row, 0, &selected_name);
+    gtk_clist_get_text(GTK_CLIST(clist), selected_row, 2, &selected_version);
+    gtk_clist_get_text(GTK_CLIST(clist), selected_row, 3, &selected_enabled);
+}
+
+void plugins_clist_unselect_cb(GtkWidget *clist, gint row, gint column,
+	GdkEventButton *event, gpointer data)
+{
+    selected_row = -1;
+}
+
+static void
+plugins_enable_cb(GtkWidget *button, gpointer clist)
+{
+    plugin    *pt_plug;
+    void     (*proto_init) ();
+
+    /* nothing selected */
+    if (selected_row == -1) return;
+    /* already enabled */
+    if (!strcmp(selected_enabled, "Yes")) return;
+
+    if ((pt_plug = enable_plugin(selected_name, selected_version)) == NULL)
+    {
+	simple_dialog(ESD_TYPE_WARN, NULL, "Plugin not found");
+	return;
+    }
+    proto_init = (void (*)())dlsym(pt_plug->handle, "proto_init");
+    if (proto_init)
+	proto_init();
+
+    gtk_clist_set_text(GTK_CLIST(clist), selected_row, 3, "Yes");
+}
+
+static void
+plugins_disable_cb(GtkWidget *button, gpointer clist)
+{
+    plugin    *pt_plug;
+
+    /* nothing selected */
+    if (selected_row == -1) return;
+    /* already disabled */
+    if (!strcmp(selected_enabled, "No")) return;
+
+    if ((pt_plug = disable_plugin(selected_name, selected_version)) == NULL)
+    {
+	simple_dialog(ESD_TYPE_WARN, NULL, "Plugin not found");
+	return;
+    }
+    gtk_clist_set_text(GTK_CLIST(clist), selected_row, 3, "No");
+}
+
+static void
+plugins_filter_cb(GtkWidget *button, gpointer clist)
+{
+    GtkWidget *filter_window;
+    GtkWidget *filter_vbox;
+    GtkWidget *filter_frame;
+    GtkWidget *filter_entry;
+    GtkWidget *filter_hbnbox;
+    GtkWidget *ok_bn;
+    GtkWidget *cancel_bn;
+    plugin    *pt_plug;
+
+    if (selected_row == -1) return;
+    pt_plug = find_plugin(selected_name, selected_version);
+
+    filter_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+    gtk_window_set_title(GTK_WINDOW(filter_window), "Ethereal: Plugin Filter");
+    gtk_window_set_modal(GTK_WINDOW(filter_window), TRUE);
+
+    filter_vbox = gtk_vbox_new(FALSE, 0);
+    gtk_container_add(GTK_CONTAINER(filter_window), filter_vbox);
+    gtk_widget_show(filter_vbox);
+
+    filter_frame = gtk_frame_new("Plugin Filter");
+    gtk_box_pack_start(GTK_BOX(filter_vbox), filter_frame, TRUE, TRUE, 0);
+    gtk_container_set_border_width(GTK_CONTAINER(filter_frame), 10);
+    gtk_widget_show(filter_frame);
+
+    filter_entry = gtk_entry_new();
+    gtk_object_set_data(GTK_OBJECT(filter_window), PLUGINS_DFILTER_TE,
+	                filter_entry);
+    gtk_container_add(GTK_CONTAINER(filter_frame), filter_entry);
+    gtk_entry_set_text(GTK_ENTRY(filter_entry), pt_plug->filter_string);
+    if (!strcmp(selected_enabled, "Yes"))
+	gtk_entry_set_editable(GTK_ENTRY(filter_entry), TRUE);
+    else
+	gtk_entry_set_editable(GTK_ENTRY(filter_entry), FALSE);
+    gtk_widget_show(filter_entry);
+
+    filter_hbnbox = gtk_hbutton_box_new();
+    gtk_box_pack_start(GTK_BOX(filter_vbox), filter_hbnbox, FALSE, TRUE, 0);
+    gtk_container_set_border_width(GTK_CONTAINER(filter_hbnbox), 10);
+    gtk_widget_show(filter_hbnbox);
+
+    ok_bn = gtk_button_new_with_label("Ok");
+    gtk_container_add(GTK_CONTAINER(filter_hbnbox), ok_bn);
+    gtk_widget_show(ok_bn);
+    gtk_signal_connect(GTK_OBJECT(ok_bn), "clicked",
+	    GTK_SIGNAL_FUNC(filter_ok_cb), GTK_OBJECT(filter_window));
+
+    cancel_bn = gtk_button_new_with_label("Cancel");
+    gtk_container_add(GTK_CONTAINER(filter_hbnbox), cancel_bn);
+    gtk_widget_show(cancel_bn);
+    gtk_signal_connect(GTK_OBJECT(cancel_bn), "clicked",
+	    GTK_SIGNAL_FUNC(filter_cancel_cb), GTK_OBJECT(filter_window));
+
+    gtk_widget_show(filter_window);
+}
+
+static void
+filter_ok_cb(GtkWidget *close_bt, gpointer parent_w)
+{
+    GtkWidget *filter_entry;
+    gchar     *filter_string;
+    dfilter   *filter = NULL;
+
+    if (!strcmp(selected_enabled, "Yes"))
+    {
+	filter_entry = gtk_object_get_data(GTK_OBJECT(parent_w), PLUGINS_DFILTER_TE);
+	filter_string = gtk_entry_get_text(GTK_ENTRY(filter_entry));
+	if (dfilter_compile(filter_string, &filter) != 0)
+	{
+	    simple_dialog(ESD_TYPE_WARN, NULL, dfilter_error_msg);
+	}
+	else
+	    plugin_replace_filter(selected_name, selected_version,
+		                  filter_string, filter);
+    }
+    gtk_grab_remove(GTK_WIDGET(parent_w));
+    gtk_widget_destroy(GTK_WIDGET(parent_w));
+}
+
+static void
+filter_cancel_cb(GtkWidget *close_bt, gpointer parent_w)
+{
+    gtk_grab_remove(GTK_WIDGET(parent_w));
+    gtk_widget_destroy(GTK_WIDGET(parent_w));
+}
+#endif
diff --git a/packet-tcp.c b/packet-tcp.c
index b2f0174e02..7e922e197c 100644
--- a/packet-tcp.c
+++ b/packet-tcp.c
@@ -1,7 +1,7 @@
 /* packet-tcp.c
  * Routines for TCP packet disassembly
  *
- * $Id: packet-tcp.c,v 1.52 1999/12/09 04:06:53 nneul Exp $
+ * $Id: packet-tcp.c,v 1.53 1999/12/09 20:41:25 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -37,7 +37,7 @@
 
 #include <stdio.h>
 #include <glib.h>
-#include "packet.h"
+#include "globals.h"
 #include "resolv.h"
 #include "follow.h"
 #include "util.h"
@@ -51,6 +51,10 @@
 # include "snprintf.h"
 #endif
 
+#ifdef HAVE_DLFCN_H
+#include "plugins.h"
+#endif
+
 #ifndef __PACKET_IP_H__
 #include "packet-ip.h"
 #endif
@@ -482,6 +486,22 @@ dissect_tcp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
      (it could be an ACK-only packet) */
   if (packet_max > offset) {
 
+    /* try to apply the plugins */
+#ifdef HAVE_DLFCN_H
+    plugin *pt_plug = plugin_list;
+
+    if (pt_plug) {
+      while (pt_plug) {
+	if (pt_plug->enabled && !strcmp(pt_plug->protocol, "tcp") &&
+	    tree && dfilter_apply(pt_plug->filter, tree, pd)) {
+	  pt_plug->dissector(pd, offset, fd, tree);
+	  goto reas;
+	}
+	pt_plug = pt_plug->next;
+      }
+    }
+#endif
+
     /* ONC RPC.  We can't base this on anything in the TCP header; we have
        to look at the payload.  If "dissect_rpc()" returns TRUE, it was
        an RPC packet, otherwise it's some other type of packet. */
diff --git a/packet-udp.c b/packet-udp.c
index e422e6f03b..08d076877d 100644
--- a/packet-udp.c
+++ b/packet-udp.c
@@ -1,7 +1,7 @@
 /* packet-udp.c
  * Routines for UDP packet disassembly
  *
- * $Id: packet-udp.c,v 1.41 1999/12/07 06:10:00 guy Exp $
+ * $Id: packet-udp.c,v 1.42 1999/12/09 20:41:26 oabad Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -41,9 +41,13 @@
 #include <stdlib.h>
 
 #include <glib.h>
-#include "packet.h"
+#include "globals.h"
 #include "resolv.h"
 
+#ifdef HAVE_DLFCN_H
+#include "plugins.h"
+#endif
+
 static int proto_udp = -1;		
 static int hf_udp_srcport = -1;
 static int hf_udp_dstport = -1;
@@ -239,6 +243,24 @@ dissect_udp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
   if (dissect_rpc(pd, offset, fd, tree))
     return;
 
+  /* try to apply the plugins */
+#ifdef HAVE_DLFCN_H
+  {
+      plugin *pt_plug = plugin_list;
+
+      if (pt_plug) {
+	  while (pt_plug) {
+	      if (pt_plug->enabled && !strcmp(pt_plug->protocol, "udp") &&
+		  tree && dfilter_apply(pt_plug->filter, tree, pd)) {
+		  pt_plug->dissector(pd, offset, fd, tree);
+		  return;
+	      }
+	      pt_plug = pt_plug->next;
+	  }
+      }
+  }
+#endif
+
   /* XXX - we should do all of this through the table of ports. */
 #define PORT_IS(port)	(uh_sport == port || uh_dport == port)
   if (PORT_IS(UDP_PORT_BOOTPS))
diff --git a/plugins.c b/plugins.c
new file mode 100644
index 0000000000..0ed0899e65
--- /dev/null
+++ b/plugins.c
@@ -0,0 +1,204 @@
+/* plugins.c
+ * definitions for plugins structures
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 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
+
+#ifdef HAVE_DLFCN_H
+
+#include <time.h>
+
+#include "globals.h"
+
+#include "plugins.h"
+
+/* linked list of all plugins */
+plugin *plugin_list;
+
+/*
+ * 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.
+ */
+int
+add_plugin(void *handle, gchar *name, gchar *version, gchar *protocol,
+	   gchar *filter_string, dfilter *filter,
+	   void (*dissector) (const u_char *,
+	                      int,
+			      frame_data *,
+			      proto_tree *))
+{
+    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->enabled = FALSE;
+    new_plug->protocol = protocol;
+    new_plug->filter_string = g_strdup(filter_string);
+    new_plug->filter = filter;
+    new_plug->dissector = dissector;
+    new_plug->next = NULL;
+    return 0;
+}
+
+/*
+ * enable a plugin
+ * returns a pointer to the enabled plugin, or NULL if the plugin wasn't found
+ * in the list
+ */
+void *
+enable_plugin(const gchar *name, const gchar *version)
+{
+    plugin *pt_plug;
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	if (!strcmp(pt_plug->name, name) && !strcmp(pt_plug->version, version))
+	{
+	    pt_plug->enabled = TRUE;
+	    return pt_plug;
+	}
+	pt_plug = pt_plug->next;
+    }
+    return NULL;
+}
+
+/*
+ * disable a plugin
+ * returns a pointer to the disabled plugin, or NULL if the plugin wasn't found
+ * in the list
+ */
+void *
+disable_plugin(const gchar *name, const gchar *version)
+{
+    plugin *pt_plug;
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	if (!strcmp(pt_plug->name, name) && !strcmp(pt_plug->version, version))
+	{
+	    pt_plug->enabled = FALSE;
+	    return pt_plug;
+	}
+	pt_plug = pt_plug->next;
+    }
+    return NULL;
+}
+
+/*
+ * find a plugin using its name/version
+ */
+void *
+find_plugin(const gchar *name, const gchar *version)
+{
+    plugin *pt_plug;
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	if (!strcmp(pt_plug->name, name) && !strcmp(pt_plug->version, version))
+	{
+	    return pt_plug;
+	}
+	pt_plug = pt_plug->next;
+    }
+    return NULL;
+}
+
+/*
+ * check if a plugin is enabled
+ */
+gboolean
+is_enabled(const gchar *name, const gchar *version)
+{
+    plugin *pt_plug;
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	if (!strcmp(pt_plug->name, name) && !strcmp(pt_plug->version, version))
+	    return pt_plug->enabled;
+	pt_plug = pt_plug->next;
+    }
+    return FALSE;
+}
+
+/*
+ * replace the filter used by a plugin (filter string and dfilter)
+ */
+void
+plugin_replace_filter(const gchar *name, const gchar *version,
+	const gchar *filter_string, dfilter *filter)
+{
+    plugin *pt_plug;
+
+    pt_plug = plugin_list;
+    while (pt_plug)
+    {
+	if (!strcmp(pt_plug->name, name) && !strcmp(pt_plug->version, version))
+	{
+	    g_free(pt_plug->filter_string);
+	    pt_plug->filter_string = g_strdup(filter_string);
+	    dfilter_destroy(pt_plug->filter);
+	    pt_plug->filter = filter;
+	    return;
+	}
+	pt_plug = pt_plug->next;
+    }
+}
+
+#endif
diff --git a/plugins.h b/plugins.h
new file mode 100644
index 0000000000..a1c56b1b48
--- /dev/null
+++ b/plugins.h
@@ -0,0 +1,52 @@
+/* plugins.h
+ * definitions for plugins structures
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 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.
+ */
+
+#ifndef __PLUGINS_H__
+#define __PLUGINS_H__
+
+typedef struct _plugin {
+    void    *handle;          /* handle returned by dlopen */
+    gchar   *name;            /* plugin name */
+    gchar   *version;         /* plugin version */
+    gboolean enabled;         /* is it active ? */
+    gchar   *protocol;        /* protocol which should call the dissector
+			       * for this plugin eg "tcp" */
+    gchar   *filter_string;   /* display filter string matching frames for
+			       * which the dissector should be used */
+    dfilter *filter;          /* compiled display filter */
+    /* the dissector */
+    void (*dissector) (const u_char *, int, frame_data *, proto_tree *);
+    struct _plugin *next;     /* forward link */
+} plugin;
+
+extern plugin *plugin_list;
+
+int add_plugin(void *, gchar *, gchar *, gchar *, gchar *, dfilter *,
+	          void (*) (const u_char *, int, frame_data *, proto_tree *));
+void *enable_plugin(const gchar *, const gchar *);
+void *disable_plugin(const gchar *, const gchar *);
+void *find_plugin(const gchar *, const gchar *);
+gboolean is_enabled(const gchar *, const gchar *);
+void plugin_replace_filter(const gchar *, const gchar *, const gchar *, dfilter *);
+
+#endif /* __PLUGINS_H__ */