From Håkon Nessjøen via bug 4899:

Dissector for Mikrotik RouterOS protocol for telneting without using IP
addresses.

From me:
Code cleanup.

svn path=/trunk/; revision=33289

1 files changed, 328 insertions, 0 deletions

diff --git a/epan/dissectors/packet-mactelnet.c b/epan/dissectors/packet-mactelnet.c
new file mode 100644
index 0000000000..a45588fd39
--- /dev/null
+++ b/epan/dissectors/packet-mactelnet.c
@@ -0,0 +1,328 @@
+/* packet-mactelnet.c
+ * Routines for MAC-Telnet dissection
+ * Copyright 2010, Haakon Nessjoen <haakon.nessjoen@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * Thanks to "omniflux" for dissecting the protocol by hand before me.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <string.h>
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+#include <epan/addr_resolv.h>
+
+#define PROTO_TAG_MACTELNET "MAC-Telnet"
+
+void proto_reg_handoff_mactelnet(void);
+
+/* Initialize the protocol and registered fields */
+static gint proto_mactelnet = -1;
+static gint hf_mactelnet = -1;
+static gint hf_mactelnet_type = -1;
+static gint hf_mactelnet_protocolver = -1;
+static gint hf_mactelnet_source_mac = -1;
+static gint hf_mactelnet_destination_mac = -1;
+static gint hf_mactelnet_session_id = -1;
+static gint hf_mactelnet_client_type = -1;
+static gint hf_mactelnet_databytes = -1;
+static gint hf_mactelnet_datatype = -1;
+static gint hf_mactelnet_control = -1;
+static gint hf_mactelnet_control_length = -1;
+static gint hf_mactelnet_control_encryption_key = -1;
+static gint hf_mactelnet_control_password = -1;
+static gint hf_mactelnet_control_username = -1;
+static gint hf_mactelnet_control_terminal = -1;
+static gint hf_mactelnet_control_width = -1;
+static gint hf_mactelnet_control_height = -1;
+
+/* Global port pref */
+static int global_mactelnet_port = 20561;
+
+/* Control packet definition */
+static guint32 control_packet = 0x563412FF;
+
+/* Initialize the subtree pointers */
+static gint ett_mactelnet = -1;
+static gint ett_mactelnet_control = -1;
+
+static dissector_handle_t data_handle;
+
+/* Packet types */
+static const value_string packettypenames[] = {
+	{ 0, "Start session" },
+	{ 1, "Data" },
+	{ 2, "Acknowledge" },
+	{ 255, "End session" },
+	{ 0, NULL }
+};	
+
+/* Known client types */
+static const value_string clienttypenames[] = {
+	{ 0x0015, "MAC Telnet" },
+	{ 0x0f90, "Winbox" },
+	{ 0, NULL }
+};	
+
+/* Known control-packet types */
+static const value_string controlpackettypenames[] = {
+	{ 0, "Begin authentication" },
+	{ 1, "Encryption key" },
+	{ 2, "Password" },
+	{ 3, "Username" },
+	{ 4, "Terminal type" },
+	{ 5, "Terminal width" },
+	{ 6, "Terminal height" },
+	{ 9, "End authentication" },
+	{ 0, NULL }
+};	
+
+
+static int
+dissect_mactelnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_item *mactelnet_item = NULL;
+	proto_tree *mactelnet_tree = NULL;
+	proto_item *mactelnet_control_item = NULL;
+	proto_tree *mactelnet_control_tree = NULL;
+	guint16 type = 0;
+
+	/* Check that there's enough data */
+	if (tvb_length(tvb) < 22)
+		return 0;
+
+	/* Make entries in Protocol column and Info column on summary display */
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_TAG_MACTELNET);
+
+	/*  Get the type byte */
+	type = tvb_get_guint8(tvb, 1);
+
+	col_clear(pinfo->cinfo, COL_INFO);
+	col_add_fstr(pinfo->cinfo, COL_INFO, "%s > %s Type: %s",
+	ether_to_str(tvb_get_ptr(tvb, 2, 6)), ether_to_str(tvb_get_ptr(tvb, 8, 6)),
+		     val_to_str(type, packettypenames, "Unknown Type:0x%02x"));
+
+	if (tree) {
+		guint8 no_ip[4] = {0,0,0,0};
+		guint8 offset = 0;
+
+		/* create display subtree for the protocol */
+		mactelnet_item = proto_tree_add_item(tree, proto_mactelnet, tvb, 0, -1, FALSE);
+		mactelnet_tree = proto_item_add_subtree(mactelnet_item, ett_mactelnet);
+
+		/* ver(1) */
+		proto_tree_add_item(mactelnet_tree, hf_mactelnet_protocolver, tvb, offset, 1, ENC_NA);
+		offset++;
+
+		/* ptype(1) */
+		proto_tree_add_item(mactelnet_tree, hf_mactelnet_type, tvb, offset, 1, ENC_NA);
+		offset++;
+
+		/* saddr(6) */
+		proto_tree_add_item(mactelnet_tree, hf_mactelnet_source_mac, tvb, offset, 6, ENC_NA);
+		offset += 6;
+
+		/* dstaddr(6) */
+		proto_tree_add_item(mactelnet_tree, hf_mactelnet_destination_mac, tvb, offset, 6, ENC_NA);
+		offset += 6;
+
+		if (memcmp(pinfo->src.data, &no_ip, 4) == 0) {
+			/* Server to client */
+
+			/* sessionid(2) */
+			proto_tree_add_item(mactelnet_tree, hf_mactelnet_session_id, tvb, offset+2, 2, ENC_BIG_ENDIAN);
+			offset += 2;
+
+			/* clienttype(2) */
+			proto_tree_add_item(mactelnet_tree, hf_mactelnet_client_type, tvb, offset-2, 2, ENC_BIG_ENDIAN);
+			offset += 2;
+		} else {
+			/* Client to server */
+
+			/* sessionid(2) */
+			proto_tree_add_item(mactelnet_tree, hf_mactelnet_session_id, tvb, offset, 2, ENC_BIG_ENDIAN);
+			offset += 2;
+
+			/* clienttype(2) */
+			proto_tree_add_item(mactelnet_tree, hf_mactelnet_client_type, tvb, offset, 2, ENC_BIG_ENDIAN);
+			offset += 2;
+		} 
+
+		/* counter(4) */
+		proto_tree_add_item(mactelnet_tree, hf_mactelnet_databytes, tvb, offset, 4, ENC_BIG_ENDIAN);
+		offset += 4;
+
+		/* Data packets only */
+		if (type == 1) {
+			while(tvb_length_remaining(tvb, offset) > 0) {
+				if (tvb_length_remaining(tvb, offset) > 4 && tvb_get_ntohl(tvb, offset) == control_packet) {
+					guint8 datatype = 0;
+					guint32 datalength = 0;
+					offset += 4;
+
+					/* Add subtree for control packet */
+					mactelnet_control_item = proto_tree_add_item(mactelnet_tree, hf_mactelnet_control, tvb, offset, -1, ENC_NA);
+					mactelnet_control_tree = proto_item_add_subtree(mactelnet_control_item, ett_mactelnet);
+
+					/* Control packet type (1) */
+	 				datatype = tvb_get_guint8(tvb, offset);
+					proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_datatype, tvb, offset, 1, ENC_NA);
+					offset++;
+
+					/* Control packet length (4) */
+					datalength = tvb_get_ntohl(tvb, offset);
+					proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_length, tvb, offset, 4, ENC_BIG_ENDIAN);
+					offset += 4;
+
+					switch (datatype) {
+						case 1: /* Encryption Key */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_encryption_key, tvb, offset, datalength, ENC_NA);
+							break;
+
+						case 2: /* Password */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_password, tvb, offset, datalength, ENC_NA);
+							break;
+
+						case 3: /* Username */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_username, tvb, offset, datalength, ENC_NA);
+							break;
+
+						case 4: /* Terminal type */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_terminal, tvb, offset, datalength, ENC_NA);
+							break;
+
+						case 5: /* Terminal width */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_width, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+							break;
+
+						case 6: /* Terminal height */
+							proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_height, tvb, offset, 2, ENC_LITTLE_ENDIAN);
+							break;
+
+						case 9:	/* End authentication (no data) */
+							break;
+					}
+					offset += datalength;
+
+				} else {
+					/* Data packet, let wireshark handle it */
+					tvbuff_t        *next_client;
+					next_client = tvb_new_subset(tvb, offset, -1, -1);
+					call_dissector(data_handle, next_client, pinfo, mactelnet_tree);
+					return offset;
+				}
+			}
+		}
+
+
+	}
+	return tvb_length(tvb);
+}
+
+
+void
+proto_register_mactelnet(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_mactelnet,
+		{ "Data", "mactelnet.data", FT_NONE, BASE_NONE, NULL, 0x0,
+		  "MAC-Telnet Data", HFILL }},
+		{ &hf_mactelnet_type,
+		{ "Type", "mactelnet.type", FT_UINT8, BASE_DEC, VALS(packettypenames), 0x0,
+		  "Package Type", HFILL }},
+		{ &hf_mactelnet_protocolver,
+		{ "Protocol Version", "mactelnet.protocol_version", FT_UINT8, BASE_DEC, NULL, 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_source_mac,
+		{ "Source MAC", "mactelnet.source_mac", FT_ETHER, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_destination_mac,
+		{ "Destination MAC", "mactelnet.destination_mac", FT_ETHER, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_session_id,
+		{ "Session ID", "mactelnet.session_id", FT_UINT16, BASE_HEX, NULL , 0x0,
+		 "Session ID for this connection", HFILL }},
+		{ &hf_mactelnet_client_type,
+		{ "Client Type", "mactelnet.client_type", FT_UINT16, BASE_HEX, VALS(clienttypenames) , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_databytes,
+		{ "Session Data Bytes", "mactelnet.session_bytes", FT_UINT32, BASE_DEC, NULL , 0x0,
+		  "Session data bytes received", HFILL }},
+		{ &hf_mactelnet_datatype,
+		{ "Data Packet Type", "mactelnet.data_type", FT_UINT8, BASE_HEX, VALS(controlpackettypenames) , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control,
+		{ "Control Packet", "mactelnet.control", FT_NONE, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control_length,
+		{ "Control Data Length", "mactelnet.control_length", FT_UINT32, BASE_DEC, NULL , 0x0,
+		  "Control packet length", HFILL }},
+		{ &hf_mactelnet_control_encryption_key,
+		{ "Encryption Key", "mactelnet.control_encryptionkey", FT_BYTES, BASE_NONE, NULL , 0x0,
+		  "Login encryption key", HFILL }},
+		{ &hf_mactelnet_control_password,
+		{ "Password MD5", "mactelnet.control_password", FT_BYTES, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control_username,
+		{ "Username", "mactelnet.control_username", FT_STRING, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control_terminal,
+		{ "Terminal Type", "mactelnet.control_terminaltype", FT_STRING, BASE_NONE, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control_width,
+		{ "Terminal Width", "mactelnet.control_width", FT_UINT16, BASE_DEC, NULL , 0x0,
+		  NULL, HFILL }},
+		{ &hf_mactelnet_control_height,
+		{ "Terminal Height", "mactelnet.control_height", FT_UINT16, BASE_DEC, NULL , 0x0,
+		  NULL, HFILL }}
+	};
+
+	/* Setup protocol subtree array */
+	static gint *ett[] = {
+		&ett_mactelnet,
+		&ett_mactelnet_control,
+	};
+
+	/* Register the protocol name and description */
+	proto_mactelnet = proto_register_protocol ("MikroTik MAC-Telnet Protocol", PROTO_TAG_MACTELNET, "mactelnet");
+
+	/* Required function calls to register the header fields and subtrees used */
+	proto_register_field_array (proto_mactelnet, hf, array_length (hf));
+	proto_register_subtree_array (ett, array_length (ett));
+}
+
+void
+proto_reg_handoff_mactelnet(void)
+{
+	dissector_handle_t mactelnet_handle;
+	mactelnet_handle = new_create_dissector_handle(dissect_mactelnet,
+							 proto_mactelnet);
+	dissector_add("udp.port", global_mactelnet_port, mactelnet_handle);
+	data_handle = find_dissector("data");
+}