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/* packet-mactelnet.c
* Routines for MAC-Telnet dissection
* Copyright 2010, Haakon Nessjoen <haakon.nessjoen@gmail.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* Thanks to "omniflux" for dissecting the protocol by hand before me.
* http://www.omniflux.com/devel/mikrotik/Mikrotik_MAC_Telnet_Procotol.txt
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/to_str.h>
void proto_register_mactelnet(void);
void proto_reg_handoff_mactelnet(void);
#define PROTO_TAG_MACTELNET "MAC-Telnet"
/* Initialize the protocol and registered fields */
static gint proto_mactelnet = -1;
static gint hf_mactelnet_control_packet = -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;
#define MACTELNET_UDP_PORT 20561 /* Not IANA registered */
/* Control packet definition */
static const guint32 control_packet = 0x563412FF;
/* Initialize the subtree pointers */
static gint ett_mactelnet = -1;
static gint ett_mactelnet_control = -1;
/* Packet types */
static const value_string packettypenames[] = {
{ 0, "Start session" },
{ 1, "Data" },
{ 2, "Acknowledge" },
{ 4, "Ping request" },
{ 5, "Ping response" },
{ 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, void *data _U_)
{
proto_item *mactelnet_item;
proto_tree *mactelnet_tree;
proto_item *mactelnet_control_item;
proto_tree *mactelnet_control_tree;
int foundping = -1;
int foundclient = -1;
int foundserver = -1;
guint16 type;
/* Check that there's enough data */
if (tvb_captured_length(tvb) < 18)
return 0;
/* Get the type byte */
type = tvb_get_guint8(tvb, 1);
if ((type == 4) || (type == 5)) { /* Ping */
foundping = 1;
} else {
int i = 0;
while (clienttypenames[i].strptr != NULL) {
if (tvb_get_ntohs(tvb, 14) == clienttypenames[i].value) {
foundserver = i;
break;
}
if (tvb_get_ntohs(tvb, 16) == clienttypenames[i].value) {
foundclient = i;
break;
}
i++;
}
}
/* Not a mactelnet packet */
if ((foundping < 0) && (foundclient < 0) && (foundserver < 0)) {
return 0;
}
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_TAG_MACTELNET);
col_add_fstr(pinfo->cinfo, COL_INFO, "%s > %s Direction: %s Type: %s",
tvb_ether_to_str(pinfo->pool, tvb, 2),
tvb_ether_to_str(pinfo->pool, tvb, 8),
((foundclient >= 0) || (type == 4) ? "Client->Server" : "Server->Client" ),
val_to_str(type, packettypenames, "Unknown Type:0x%02x")
);
if (tree) {
guint32 offset = 0;
/* create display subtree for the protocol */
mactelnet_item = proto_tree_add_item(tree, proto_mactelnet, tvb, 0, -1, ENC_NA);
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 += 1;
/* ptype(1) */
proto_tree_add_item(mactelnet_tree, hf_mactelnet_type, tvb, offset, 1, ENC_NA);
offset += 1;
/* 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 (foundserver >= 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 if (foundclient >= 0) {
/* 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;
} else if (foundping >= 0) {
/* Skip empty data */
offset += 4;
}
if (foundping < 0) {
/* 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_reported_length_remaining(tvb, offset) > 0) {
if ((tvb_reported_length_remaining(tvb, offset) > 4) && (tvb_get_ntohl(tvb, offset) == control_packet)) {
guint8 datatype;
guint32 datalength;
/* 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 magic number (4) */
proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_packet, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
/* 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 += 1;
/* 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_ASCII);
break;
case 4: /* Terminal type */
proto_tree_add_item(mactelnet_control_tree, hf_mactelnet_control_terminal, tvb, offset, datalength, ENC_ASCII);
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;
}
proto_item_set_len (mactelnet_control_item, datalength + 9);
offset += datalength;
} else {
/* Data packet, let wireshark handle it */
tvbuff_t *next_client = tvb_new_subset_remaining(tvb, offset);
return call_data_dissector(next_client, pinfo, mactelnet_tree);
}
}
} else if ((type == 4) || (type == 5)) {
/* Data packet, let wireshark handle it */
tvbuff_t *next_client = tvb_new_subset_remaining(tvb, offset);
return call_data_dissector(next_client, pinfo, mactelnet_tree);
}
}
return tvb_reported_length(tvb);
}
void
proto_register_mactelnet(void)
{
static hf_register_info hf[] = {
{ &hf_mactelnet_control_packet,
{ "Control Packet Magic Number", "mactelnet.control_packet",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
{ &hf_mactelnet_type,
{ "Type", "mactelnet.type",
FT_UINT8, BASE_DEC, VALS(packettypenames), 0x0,
"Packet 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 padded MD5 password", 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");
register_dissector("mactelnet", dissect_mactelnet, proto_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_add_uint_with_preference("udp.port", MACTELNET_UDP_PORT, find_dissector("mactelnet"));
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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