Add a dissector to handle IEEE 802a's OUI Extended Ethertype; dissectors

can register an OUI, and PIDs for that OUI, in the same fashion that
they can do so for SNAP (after which the 802a OUI Extended Ethertype is
clearly modeled).

svn path=/trunk/; revision=12967

1 files changed, 195 insertions, 0 deletions

diff --git a/epan/dissectors/packet-ieee802a.c b/epan/dissectors/packet-ieee802a.c
new file mode 100644
index 0000000000..f01069971e
--- /dev/null
+++ b/epan/dissectors/packet-ieee802a.c
@@ -0,0 +1,195 @@
+/* packet-ieee802a.c
+ * Routines for IEEE 802a
+ *
+ * $Id$
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * 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
+
+#include <glib.h>
+#include <epan/packet.h>
+#include "oui.h"
+#include "etypes.h"
+
+#include "packet-ieee802a.h"
+
+static int proto_ieee802a = -1;
+static int hf_ieee802a_oui = -1;
+static int hf_ieee802a_pid = -1;
+
+static gint ett_ieee802a = -1;
+
+static dissector_handle_t data_handle;
+
+/*
+ * Hash table for translating OUIs to a dissector table/field info pair;
+ * the dissector table maps PID values to dissectors, and the field
+ * corresponds to the PID for that OUI.
+ */
+typedef struct {
+	dissector_table_t table;
+	hf_register_info *field_info;
+} oui_info_t;
+
+static GHashTable *oui_info_table = NULL;
+
+/*
+ * Add an entry for a new OUI.
+ */
+void
+ieee802a_add_oui(guint32 oui, const char *table_name, char *table_ui_name,
+    hf_register_info *hf_item)
+{
+	oui_info_t *new_info;
+
+	new_info = g_malloc(sizeof (oui_info_t));
+	new_info->table = register_dissector_table(table_name,
+	    table_ui_name, FT_UINT16, BASE_HEX);
+	new_info->field_info = hf_item;
+
+	/*
+	 * Create the hash table for OUI information, if it doesn't
+	 * already exist.
+	 */
+	if (oui_info_table == NULL) {
+		oui_info_table = g_hash_table_new(g_direct_hash,
+		    g_direct_equal);
+	}
+	g_hash_table_insert(oui_info_table, GUINT_TO_POINTER(oui), new_info);
+}
+
+static void
+dissect_ieee802a(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree	*ieee802a_tree = NULL;
+	proto_item	*ti;
+	int		offset = 0;
+	tvbuff_t	*next_tvb;
+	guint32		oui;
+	guint16		etype;
+	oui_info_t	*oui_info;
+	dissector_table_t subdissector_table;
+	int		hf;
+
+	if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, "IEEE802a");
+	}
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_clear(pinfo->cinfo, COL_INFO);
+	}
+
+	if (tree) {
+		ti = proto_tree_add_item(tree, proto_ieee802a, tvb, 0, -1, FALSE);
+		ieee802a_tree = proto_item_add_subtree(ti, ett_ieee802a);
+	} else
+		ieee802a_tree = NULL;
+
+	oui =	tvb_get_ntoh24(tvb, offset);
+	etype = tvb_get_ntohs(tvb, offset+3);
+
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_add_fstr(pinfo->cinfo, COL_INFO,
+		    "OUI 0x%06X (%s), PID 0x%04X",
+		    oui, val_to_str(oui, oui_vals, "Unknown"), etype);
+	}
+	if (tree) {
+		proto_tree_add_uint(ieee802a_tree, hf_ieee802a_oui,
+		    tvb, offset, 3, oui);
+	}
+
+	/*
+	 * Do we have information for this OUI?
+	 */
+	if (oui_info_table != NULL &&
+	    (oui_info = g_hash_table_lookup(oui_info_table,
+	      GUINT_TO_POINTER(oui))) != NULL) {
+		/*
+		 * Yes - use it.
+		 */
+		hf = *oui_info->field_info->p_id;
+		subdissector_table = oui_info->table;
+	} else {
+		/*
+		 * No, use hf_ieee802a_pid for the PID and just dissect
+		 * the payload as data.
+		 */
+		hf = hf_ieee802a_pid;
+		subdissector_table = NULL;
+	}
+	if (tree)
+		proto_tree_add_uint(ieee802a_tree, hf, tvb, offset+3, 2, etype);
+	next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
+	if (subdissector_table != NULL) {
+		/* do lookup with the subdissector table */
+		if (dissector_try_port(subdissector_table, etype, next_tvb,
+		    pinfo, tree))
+			return;
+	}
+	call_dissector(data_handle, next_tvb, pinfo, tree);
+}
+
+void
+proto_register_ieee802a(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_ieee802a_oui,
+		{ "Organization Code",	"ieee802a.oui", FT_UINT24, BASE_HEX,
+			VALS(oui_vals), 0x0, "", HFILL }},
+
+		{ &hf_ieee802a_pid,
+		{ "Protocol ID", "ieee802a.pid", FT_UINT16, BASE_HEX,
+			NULL, 0x0, "", HFILL }}
+	};
+	static gint *ett[] = {
+		&ett_ieee802a,
+	};
+
+	proto_ieee802a = proto_register_protocol("IEEE802a OUI Extended Ethertype", "IEEE802a", "ieee802a");
+	proto_register_field_array(proto_ieee802a, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+static void
+register_hf(gpointer key _U_, gpointer value, gpointer user_data _U_)
+{
+	oui_info_t *info = value;
+
+	proto_register_field_array(proto_ieee802a, info->field_info, 1);
+}
+
+void
+proto_reg_handoff_ieee802a(void)
+{
+	dissector_handle_t ieee802a_handle;
+
+	ieee802a_handle = create_dissector_handle(dissect_ieee802a,
+	    proto_ieee802a);
+	dissector_add("ethertype", ETHERTYPE_IEEE802_OUI_EXTENDED,
+	    ieee802a_handle);
+
+	/*
+	 * Register all the fields for PIDs for various OUIs.
+	 */
+	if (oui_info_table != NULL)
+		g_hash_table_foreach(oui_info_table, register_hf, NULL);
+}