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/* packet-armagetronad.c
* Routines for the Armagetronad packet dissection
* Copyright 2005, Guillaume Chazarain <guichaz@yahoo.fr>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
void proto_register_armagetronad(void);
void proto_reg_handoff_armagetronad(void);
/* Initialize the protocol and registered fields */
static int proto_armagetronad;
static int hf_armagetronad_descriptor_id;
static int hf_armagetronad_message_id;
static int hf_armagetronad_data_len;
static int hf_armagetronad_data;
static int hf_armagetronad_sender_id;
static int hf_armagetronad_msg_subtree;
/* Initialize the subtree pointers */
static int ett_armagetronad;
static int ett_message;
static dissector_handle_t armagetronad_handle;
#define ARMAGETRONAD_UDP_PORT_RANGE "4533-4534" /* 4533 is not IANA registered, 4534 is */
/*
* 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 bool
is_armagetronad_packet(tvbuff_t * tvb)
{
int offset = 0;
/* For each message in the frame */
while (tvb_captured_length_remaining(tvb, offset) > 2) {
int 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 (!try_val_to_str(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_captured_length_remaining(tvb, offset) == 2;
}
static void
add_message_data(tvbuff_t * tvb, int offset, int data_len, proto_tree * tree)
{
if (!tree)
return;
/*
* XXX - if these are text strings, as the original dissector
* treated them as, why the byte swapping? That would make
* sense only if they're UCS-2 strings, but the rest of the
* code wasn't treating them as such.
*
* Just treat it as a byte array. If that's wrong, submit
* a change, with a sample packet, that treats it as whatever
* it is, an with a comment that *states* what it is.
*
* XXX - this claimed that "Armagetronad swaps unconditionally",
* but I'm not seeing any obvious unconditional byte-swapping
* in the code, and if somebody's never seen a big-endian
* machine in their life, they may well confuse "convert to
* network byte order" with "unconditionally swap". So
* if you want to dump this out as a sequence of shorts,
* fetch the shorts one at a time using ENC_BIG_ENDIAN.
*/
proto_tree_add_item(tree, hf_armagetronad_data, tvb, offset,
data_len, ENC_NA);
}
static int
add_message(tvbuff_t * tvb, int offset, proto_tree * tree, wmem_strbuf_t * info)
{
uint16_t descriptor_id, message_id;
int data_len;
proto_item *msg;
proto_tree *msg_tree;
const char *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, ENC_BIG_ENDIAN);
if (info)
wmem_strbuf_append_printf(info, "%s, ", descriptor);
/* MessageID field */
proto_tree_add_item(msg_tree, hf_armagetronad_message_id, tvb,
offset + 2, 2, ENC_BIG_ENDIAN);
/* DataLen field */
proto_tree_add_item(msg_tree, hf_armagetronad_data_len, tvb,
offset + 4, 2, ENC_BIG_ENDIAN);
/* Data field */
add_message_data(tvb, offset + 6, data_len, msg_tree);
return data_len + 6;
}
/* Code to actually dissect the packets */
static int
dissect_armagetronad(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void * data _U_)
{
proto_item *ti;
proto_tree *armagetronad_tree;
uint16_t sender;
int offset = 0;
wmem_strbuf_t *info;
size_t new_len;
if (!is_armagetronad_packet(tvb))
return 0;
info = wmem_strbuf_new(pinfo->pool, "");
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Armagetronad");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_armagetronad, tvb, 0, -1, ENC_NA);
armagetronad_tree = proto_item_add_subtree(ti, ett_armagetronad);
/* For each message in the frame */
while (tvb_reported_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,
ENC_BIG_ENDIAN);
new_len = wmem_strbuf_get_len(info) - 2; /* Remove the trailing ", " */
if (new_len > 0)
wmem_strbuf_truncate(info, new_len);
else
info = wmem_strbuf_new(pinfo->pool, "No message");
col_add_fstr(pinfo->cinfo, COL_INFO, "[%s] from 0x%04x",
wmem_strbuf_get_str(info), sender);
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_BYTES, 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 int *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));
armagetronad_handle = register_dissector("armagetronad", dissect_armagetronad, proto_armagetronad);
}
void proto_reg_handoff_armagetronad(void)
{
dissector_add_uint_range_with_preference("udp.port", ARMAGETRONAD_UDP_PORT_RANGE, armagetronad_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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