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Ethereal-dev: [Ethereal-dev] [patch] Partial dissector for Laplink

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

From: Brad Hards <bhards@xxxxxxxxxxxxxx>
Date: Thu, 24 Jul 2003 23:56:39 +1000
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I've done part of a dissector for the Laplink protocol.

The UDP stuff is basically done (I hope). The TCP stuff has a very long way to 
go. See attached samples.

Can this be applied? I have a lot more work to do, and would appreciate any 
captures that fail this dissector.

Brad
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? autom4te-2.5x.cache
? laplink.patch
? epan/autom4te-2.5x.cache
? wiretap/autom4te-2.5x.cache
Index: Makefile.am
===================================================================
RCS file: /cvsroot/ethereal/Makefile.am,v
retrieving revision 1.602
diff -u -3 -p -a -u -r1.602 Makefile.am
--- Makefile.am	19 Jul 2003 22:33:54 -0000	1.602
+++ Makefile.am	24 Jul 2003 13:48:42 -0000
@@ -264,6 +264,7 @@ DISSECTOR_SRC = \
 	packet-lapb.c  \
 	packet-lapbether.c \
 	packet-lapd.c  \
+	packet-laplink.c  \
 	packet-ldap.c  \
 	packet-ldp.c   \
 	packet-llc.c   \
Index: Makefile.nmake
===================================================================
RCS file: /cvsroot/ethereal/Makefile.nmake,v
retrieving revision 1.319
diff -u -3 -p -a -u -r1.319 Makefile.nmake
--- Makefile.nmake	16 Jul 2003 21:13:48 -0000	1.319
+++ Makefile.nmake	24 Jul 2003 13:48:42 -0000
@@ -205,6 +205,7 @@ DISSECTOR_SRC = \
 	packet-lapb.c  \
 	packet-lapbether.c \
 	packet-lapd.c  \
+	packet-laplink.c  \
 	packet-ldap.c  \
 	packet-ldp.c  \
 	packet-llc.c   \
Index: packet-laplink.c
===================================================================
RCS file: packet-laplink.c
diff -N packet-laplink.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ packet-laplink.c	24 Jul 2003 13:48:43 -0000
@@ -0,0 +1,221 @@
+/* packet-laplink.c
+ * Routines for laplink dissection
+ * Copyright 2003, Brad Hards <bradh@xxxxxxxxxxxxx>
+ *
+ * $Id: README.developer,v 1.75 2003/06/12 10:15:25 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@xxxxxxxxxxxx>
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <glib.h>
+
+#ifdef NEED_SNPRINTF_H
+# include "snprintf.h"
+#endif
+
+#include <epan/packet.h>
+
+#define TCP_PORT_LAPLINK 1547
+#define UDP_PORT_LAPLINK 1547
+
+/* Initialize the protocol and registered fields */
+static int proto_laplink = -1;
+static int hf_laplink_udp_ident = -1;
+static int hf_laplink_udp_name = -1;
+static int hf_laplink_tcp_ident = -1;
+static int hf_laplink_tcp_length = -1;
+static int hf_laplink_tcp_data = -1;
+
+/* Initialize the subtree pointers */
+static gint ett_laplink = -1;
+
+static const value_string laplink_udp_magic[] = {
+	{ 0x0f010000, "Name Solicitation" },
+	{ 0xf0000200, "Name Reply" },
+	{ 0, NULL }
+};
+
+static const value_string laplink_tcp_magic[] = {
+	{ 0x00000000, "Null bytes" },
+	{ 0xff08c000, "Unknown TCP query - connection?" },
+	{ 0xff08c200, "Unknown TCP query - connection?" },
+	{ 0xff0bc000, "Unknown TCP query - connection?" },
+	{ 0xff0bc200, "Unknown TCP query - connection?" },
+	{ 0xff10c000, "Unknown TCP response - connection?" },
+	{ 0xff10c200, "Unknown TCP response - connection?" },
+	{ 0xff11c000, "Unknown TCP query/response - directory list or file transfer?" },
+	{ 0xff11c200, "Unknown TCP query - directory list or file request?" },
+	{ 0xff13c000, "Unknown TCP response - connection?" },
+	{ 0xff13c200, "Unknown TCP response - connection?" },
+	{ 0xff14c000, "Unknown TCP response - directory list or file transfer?" },
+	{ 0, NULL }
+};
+
+/* Code to actually dissect the packets - UDP */
+static void
+dissect_laplink_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	int offset = 0;
+	proto_item *ti;
+	proto_tree *laplink_tree;
+	guint32 udp_ident;
+
+/* Make entries in Protocol column and Info column on summary display */
+	if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, "Laplink");
+
+	udp_ident = tvb_get_ntohl(tvb, offset);
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_add_str(pinfo->cinfo, COL_INFO,
+			    val_to_str(udp_ident, laplink_udp_magic, "Unknown UDP (%u)"));
+	}
+    
+	if (tree){
+		ti = proto_tree_add_item(tree, proto_laplink, tvb, 0, -1, FALSE);
+		laplink_tree = proto_item_add_subtree(ti, ett_laplink);
+
+		proto_tree_add_item(laplink_tree, hf_laplink_udp_ident, tvb, offset, 4, FALSE);
+		offset =+ 4;
+
+		proto_tree_add_item(laplink_tree, hf_laplink_udp_name, tvb, offset, -1, FALSE);
+	}
+}
+
+/* Code to actually dissect the packets - TCP aspects*/
+static void
+dissect_laplink_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	int offset = 0;
+	int length = 0;
+	proto_item *ti;
+	proto_tree *laplink_tree;
+	guint32 tcp_ident;
+
+/* Make entries in Protocol column and Info column on summary display */
+	if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, "Laplink");
+
+	tcp_ident = tvb_get_ntohl(tvb, offset);
+	if (check_col(pinfo->cinfo, COL_INFO)) {
+		col_add_str(pinfo->cinfo, COL_INFO,
+			    val_to_str(tcp_ident, laplink_tcp_magic, "TCP TBA (%u)"));
+	}
+    
+	if (tree){
+		ti = proto_tree_add_item(tree, proto_laplink, tvb, 0, -1, FALSE);
+
+
+		laplink_tree = proto_item_add_subtree(ti, ett_laplink);
+
+		proto_tree_add_item(laplink_tree, hf_laplink_tcp_ident, tvb, offset, 4, FALSE);
+		offset += 4;
+
+		length = tvb_get_ntohs(tvb, offset);
+		proto_tree_add_item(laplink_tree, hf_laplink_tcp_length, tvb, offset, 2, FALSE);
+		offset += 2;
+
+		proto_tree_add_item(laplink_tree, hf_laplink_tcp_data, tvb, offset, -1, FALSE);
+
+/* Continue adding tree items to process the packet here */
+
+	}
+
+
+
+/* If this protocol has a sub-dissector call it here, see section 1.8 */
+}
+
+
+/* Register the protocol with Ethereal */
+
+void
+proto_register_laplink(void)
+{                 
+
+/* Setup list of header fields  See Section 1.6.1 for details*/
+	static hf_register_info hf[] = {
+		{ &hf_laplink_udp_ident,
+			{ "UDP Ident", "laplink.udp_ident",
+			FT_UINT32, BASE_HEX, VALS(laplink_udp_magic), 0x0,          
+			"Unknown magic", HFILL }
+		},
+		{ &hf_laplink_udp_name,
+			{ "UDP Name", "laplink.udp_name",
+			FT_STRINGZ, BASE_NONE, NULL, 0x0,          
+			"Machine name", HFILL }
+		},
+		{ &hf_laplink_tcp_ident,
+			{ "TCP Ident", "laplink.tcp_ident",
+			FT_UINT32, BASE_HEX, VALS(laplink_tcp_magic), 0x0,          
+			"Unknown magic", HFILL }
+		},
+		{ &hf_laplink_tcp_length,
+			{ "TCP Data payload length", "laplink.tcp_length",
+			FT_UINT16, BASE_DEC, NULL, 0x0,          
+			"Length of remaining payload", HFILL }
+		},
+		{ &hf_laplink_tcp_data,
+			{ "Unknown TCP data", "laplink.tcp_data",
+			FT_BYTES, BASE_HEX, NULL, 0x0,          
+			"TCP data", HFILL }
+		},
+	};
+
+/* Setup protocol subtree array */
+	static gint *ett[] = {
+		&ett_laplink,
+	};
+
+/* Register the protocol name and description */
+	proto_laplink = proto_register_protocol("Laplink",
+	    "Laplink", "laplink");
+
+/* Required function calls to register the header fields and subtrees used */
+	proto_register_field_array(proto_laplink, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+
+/* If this dissector uses sub-dissector registration add a registration routine.
+   This format is required because a script is used to find these routines and
+   create the code that calls these routines.
+*/
+void
+proto_reg_handoff_laplink(void)
+{
+	dissector_handle_t laplink_udp_handle;
+	dissector_handle_t laplink_tcp_handle;
+
+	laplink_tcp_handle = create_dissector_handle(dissect_laplink_tcp,
+	    proto_laplink);
+	dissector_add("tcp.port", TCP_PORT_LAPLINK, laplink_tcp_handle);
+
+	laplink_udp_handle = create_dissector_handle(dissect_laplink_udp,
+	    proto_laplink);
+	dissector_add("udp.port", UDP_PORT_LAPLINK, laplink_udp_handle);
+}
+

Attachment: connection.cap
Description: Binary data

Attachment: discovery.cap
Description: Binary data