wireshark/epan/dissectors/packet-armagetronad.c

336 lines
8.7 KiB
C

/* packet-armagetronad.c
* Routines for the Armagetronad packet dissection
* Copyright 2005, Guillaume Chazarain <guichaz@yahoo.fr>
*
* $Id$
*
* 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., 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 <epan/emem.h>
/* Initialize the protocol and registered fields */
static int proto_armagetronad = -1;
static int hf_armagetronad_descriptor_id = -1;
static int hf_armagetronad_message_id = -1;
static int hf_armagetronad_data_len = -1;
static int hf_armagetronad_data = -1;
static int hf_armagetronad_sender_id = -1;
static int hf_armagetronad_msg_subtree = -1;
/* Initialize the subtree pointers */
static gint ett_armagetronad = -1;
static gint ett_message = -1;
#define UDP_PORT_ARMAGETRONAD 4534
#define UDP_PORT_MASTER 4533
/*
* The ACK packet is so common that we treat it
* differently: it has no MessageID
*/
#define ACK 1
/*
* armagetronad-0.2.8.2.1
* The numbers and names were retrieved at runtime using the
* 'nDescriptor* descriptors[MAXDESCRIPTORS]' array
*/
static const value_string descriptors[] = {
{1, "ack"},
{2, "req_info"},
{3, "login_deny"},
{4, "login_ignore"},
{5, "login_accept"},
{6, "login1"},
{7, "logout"},
{8, "sn_ConsoleOut"},
{9, "client_cen"},
{10, "version"},
{11, "login2"},
{20, "req_id"},
{21, "id_req_handler"},
{22, "net_destroy"},
{23, "net_control"},
{24, "net_sync"},
{25, "ready to get objects"},
{26, "net_clear"},
{27, "sync_ack"},
{28, "sync_msg"},
{40, "password_request"},
{41, "password_answer"},
{50, "small_server"},
{51, "big_server"},
{52, "small_request"},
{53, "big_request"},
{54, "big_server_master"},
{55, "big_request_master"},
{60, "transfer config"},
{200, "Chat"},
{201, "ePlayerNetID"},
{202, "player_removed_from_game"},
{203, "Chat Client"},
{210, "eTimer"},
{220, "eTeam"},
{230, "vote cast"},
{231, "Kick vote"},
{232, "Server controlled vote"},
{233, "Server controlled vote expired"},
{300, "gNetPlayerWall"},
{310, "game"},
{311, "client_gamestate"},
{320, "cycle"},
{321, "destination"},
{330, "gAIPlayer"},
{331, "gAITeam"},
{340, "zone"},
{0, NULL}
};
static gboolean
is_armagetronad_packet(tvbuff_t * tvb)
{
gint offset = 0;
/* For each message in the frame */
while (tvb_length_remaining(tvb, offset) > 2) {
gint data_len = tvb_get_ntohs(tvb, offset + 4) * 2;
#if 0
/*
* If the descriptor_id is not in the table it's possibly
* because the protocol evoluated, losing synchronization
* with the table, that's why we don't consider that as
* a heuristic
*/
if (!match_strval(tvb_get_ntohs(tvb, offset), descriptors))
/* DescriptorID not found in the table */
return FALSE;
#endif
if (!tvb_bytes_exist(tvb, offset + 6, data_len))
/* Advertised length too long */
return FALSE;
offset += 6 + data_len;
}
/* The packed should end with a 2 bytes ID */
return tvb_length_remaining(tvb, offset) == 2;
}
static void
add_message_data(tvbuff_t * tvb, gint offset, gint data_len, proto_tree * tree)
{
gchar *data = NULL;
gchar tmp;
int i;
if (!tree)
return;
data = tvb_memcpy(tvb, ep_alloc(data_len + 1), offset, data_len);
data[data_len] = '\0';
for (i = 0; i < data_len; i += 2) {
/*
* There must be a better way to tell
* Wireshark not to stop on null bytes
* as the length is known
*/
if (!data[i])
data[i] = ' ';
if (!data[i+1])
data[i+1] = ' ';
/* Armagetronad swaps unconditionally */
tmp = data[i];
data[i] = data[i+1];
data[i+1] = tmp;
}
proto_tree_add_string(tree, hf_armagetronad_data, tvb, offset,
data_len, (gchar *) data);
}
static gint
add_message(tvbuff_t * tvb, gint offset, proto_tree * tree, GString * info)
{
guint16 descriptor_id, message_id;
gint data_len;
proto_item *msg;
proto_tree *msg_tree;
const gchar *descriptor;
descriptor_id = tvb_get_ntohs(tvb, offset);
message_id = tvb_get_ntohs(tvb, offset + 2);
data_len = tvb_get_ntohs(tvb, offset + 4) * 2;
/* Message subtree */
descriptor = val_to_str(descriptor_id, descriptors, "Unknown (%u)");
if (descriptor_id == ACK)
msg = proto_tree_add_none_format(tree,
hf_armagetronad_msg_subtree,
tvb, offset, data_len + 6,
"ACK %d messages",
data_len / 2);
else
msg = proto_tree_add_none_format(tree,
hf_armagetronad_msg_subtree,
tvb, offset, data_len + 6,
"Message 0x%04x [%s]",
message_id, descriptor);
msg_tree = proto_item_add_subtree(msg, ett_message);
/* DescriptorID field */
proto_tree_add_item(msg_tree, hf_armagetronad_descriptor_id, tvb,
offset, 2, FALSE);
if (info)
g_string_append_printf(info, "%s, ", descriptor);
/* MessageID field */
proto_tree_add_item(msg_tree, hf_armagetronad_message_id, tvb,
offset + 2, 2, FALSE);
/* DataLen field */
proto_tree_add_item(msg_tree, hf_armagetronad_data_len, tvb,
offset + 4, 2, FALSE);
/* Data field */
add_message_data(tvb, offset + 6, data_len, msg_tree);
return data_len + 6;
}
/* Code to actually dissect the packets */
static gint
dissect_armagetronad(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
{
proto_item *ti;
proto_tree *armagetronad_tree;
guint16 sender;
gint offset = 0;
GString *info;
if (!is_armagetronad_packet(tvb))
return 0;
info = check_col(pinfo->cinfo, COL_INFO) ? g_string_new("") : NULL;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Armagetronad");
if (info)
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_armagetronad, tvb, 0, -1, FALSE);
armagetronad_tree = proto_item_add_subtree(ti, ett_armagetronad);
/* For each message in the frame */
while (tvb_length_remaining(tvb, offset) > 2)
offset += add_message(tvb, offset, armagetronad_tree, info);
/* After the messages, comes the SenderID */
sender = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(ti, hf_armagetronad_sender_id, tvb, offset, 2,
FALSE);
if (info) {
gsize new_len = info->len - 2; /* Remove the trailing ", " */
if (new_len > 0)
g_string_truncate(info, new_len);
else
g_string_assign(info, "No message");
col_add_fstr(pinfo->cinfo, COL_INFO, "[%s] from 0x%04x",
info->str, sender);
g_string_free(info, TRUE);
}
return offset + 2;
}
void proto_register_armagetronad(void)
{
static hf_register_info hf[] = {
{&hf_armagetronad_descriptor_id,
{"Descriptor", "armagetronad.descriptor_id",
FT_UINT16, BASE_DEC, VALS(descriptors), 0x0,
"The ID of the descriptor (the command)", HFILL}
},
{&hf_armagetronad_message_id,
{"MessageID", "armagetronad.message_id",
FT_UINT16, BASE_HEX, NULL, 0x0,
"The ID of the message (to ack it)", HFILL}
},
{&hf_armagetronad_data_len,
{"DataLen", "armagetronad.data_len",
FT_UINT16, BASE_DEC, NULL, 0x0,
"The length of the data (in shorts)", HFILL}
},
{&hf_armagetronad_data,
{"Data", "armagetronad.data",
FT_STRING, BASE_NONE, NULL, 0x0,
"The actual data (array of shorts in network order)", HFILL}
},
{&hf_armagetronad_sender_id,
{"SenderID", "armagetronad.sender_id",
FT_UINT16, BASE_HEX, NULL, 0x0,
"The ID of the sender (0x0000 for the server)", HFILL}
},
{&hf_armagetronad_msg_subtree,
{"Message", "armagetronad.message",
FT_NONE, BASE_NONE, NULL, 0x0,
"A message", HFILL}
}
};
static gint *ett[] = {
&ett_armagetronad,
&ett_message
};
proto_armagetronad =
proto_register_protocol("The Armagetron Advanced OpenGL Tron clone",
"Armagetronad", "armagetronad");
proto_register_field_array(proto_armagetronad, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
new_register_dissector("armagetronad", dissect_armagetronad,
proto_armagetronad);
}
void proto_reg_handoff_armagetronad(void)
{
dissector_handle_t armagetronad_handle;
armagetronad_handle = find_dissector("armagetronad");
dissector_add_uint("udp.port", UDP_PORT_ARMAGETRONAD, armagetronad_handle);
dissector_add_uint("udp.port", UDP_PORT_MASTER, armagetronad_handle);
}