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wireshark/epan/dissectors/packet-rsync.c

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/* packet-rsync.c
* Routines for rsync dissection
* [ very rough, but mininally functional ]
* Copyright 2003, Brad Hards <bradh@frogmouth.net>
*
* 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.
*/
#define NEW_PROTO_TREE_API
#include "config.h"
#include <epan/packet.h>
#include <epan/conversation.h>
#include <epan/prefs.h>
void proto_register_rsync(void);
#define RSYNCD_MAGIC_HEADER "@RSYNCD:"
#define RSYNCD_MAGIC_HEADER_LEN 8
#define RSYNCD_AUTHREQD "@RSYNCD: AUTHREQD "
#define RSYNCD_AUTHREQD_LEN 18
#define RSYNCD_EXIT "@RSYNCD: EXIT"
#define RSYNCD_EXIT_LEN 13
#define RSYNC_MODULE_LIST_QUERY "\n"
#define RSYNC_MODULE_LIST_QUERY_LEN 1
/* what states make sense here ? */
typedef enum _rsync_state {
RSYNC_INIT = 0,
RSYNC_SERV_INIT = 1,
RSYNC_CLIENT_QUERY = 2,
RSYNC_MODULE_LIST = 4,
RSYNC_COMMAND = 5,
RSYNC_SERV_MOTD = 6,
RSYNC_DATA = 7
} rsync_state_t;
enum rsync_who {
CLIENT,
SERVER
};
static gboolean rsync_desegment = TRUE;
/* this is a guide to the current conversation state */
struct rsync_conversation_data {
rsync_state_t client_state;
rsync_state_t server_state;
};
struct rsync_frame_data {
rsync_state_t state;
};
static header_field_info *hfi_rsync = NULL;
#define RSYNC_HF_INIT HFI_INIT(proto_rsync)
static header_field_info hfi_rsync_hdr_magic RSYNC_HF_INIT = {
"Magic Header", "rsync.hdr_magic",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_hdr_version RSYNC_HF_INIT = {
"Header Version", "rsync.hdr_version",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_query_string RSYNC_HF_INIT = {
"Client Query String", "rsync.query",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_motd_string RSYNC_HF_INIT = {
"Server MOTD String", "rsync.motd",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_module_list_string RSYNC_HF_INIT = {
"Server Module List", "rsync.module_list",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_rsyncdok_string RSYNC_HF_INIT = {
"RSYNCD Response String", "rsync.response",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_command_string RSYNC_HF_INIT = {
"Client Command String", "rsync.command",
FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL };
static header_field_info hfi_rsync_data RSYNC_HF_INIT = {
"rsync data", "rsync.data",
FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL };
static gint ett_rsync = -1;
static dissector_handle_t rsync_handle;
#define TCP_PORT_RSYNC 873
static guint glb_rsync_tcp_port = TCP_PORT_RSYNC;
#define VERSION_LEN 4 /* 2 digits for main version; '.'; 1 digit for sub version */
static void
dissect_rsync_version_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *rsync_tree, enum rsync_who me)
{
int offset = 0;
guint8 *version;
guint len;
proto_tree_add_item(rsync_tree, &hfi_rsync_hdr_magic, tvb, offset, RSYNCD_MAGIC_HEADER_LEN, ENC_ASCII|ENC_NA);
offset += RSYNCD_MAGIC_HEADER_LEN;
offset += 1; /* skip the space */
proto_tree_add_item(rsync_tree, &hfi_rsync_hdr_version, tvb, offset, -1, ENC_ASCII|ENC_NA);
len = tvb_reported_length_remaining(tvb, offset);
version = tvb_get_string_enc(wmem_packet_scope(), tvb, offset, len, ENC_ASCII|ENC_NA);
/* VERSION string can contain undesirable char (like \n) at the end. Trim it. */
if (len > 0 && version[len - 1] == '\n')
version[len - 1] = 0x0;
col_add_fstr(pinfo->cinfo, COL_INFO, "%s Initialisation (Version %s)", (me == SERVER ? "Server" : "Client"), version);
}
/* Packet dissection routine called by tcp (& udp) when port 873 detected */
static int
dissect_rsync_encap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
gboolean desegment _U_)
{
conversation_t *conversation;
struct rsync_conversation_data *conversation_data;
struct rsync_frame_data *rsync_frame_data_p;
proto_item *ti;
proto_tree *rsync_tree;
enum rsync_who me;
int offset = 0;
guint buff_length;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RSYNC");
col_clear(pinfo->cinfo, COL_INFO);
me = pinfo->srcport == glb_rsync_tcp_port ? SERVER : CLIENT;
conversation = find_or_create_conversation(pinfo);
conversation_data = (struct rsync_conversation_data *)conversation_get_proto_data(conversation, hfi_rsync->id);
if (conversation_data == NULL) { /* new conversation */
conversation_data = wmem_new(wmem_file_scope(), struct rsync_conversation_data);
conversation_data->client_state = RSYNC_INIT;
conversation_data->server_state = RSYNC_SERV_INIT;
conversation_add_proto_data(conversation, hfi_rsync->id, conversation_data);
}
conversation_set_dissector(conversation, rsync_handle);
ti = proto_tree_add_item(tree, hfi_rsync, tvb, 0, -1, ENC_NA);
rsync_tree = proto_item_add_subtree(ti, ett_rsync);
rsync_frame_data_p = (struct rsync_frame_data *)p_get_proto_data(wmem_file_scope(), pinfo, hfi_rsync->id, 0);
if (!rsync_frame_data_p) {
/* then we haven't seen this frame before */
rsync_frame_data_p = wmem_new(wmem_file_scope(), struct rsync_frame_data);
rsync_frame_data_p->state = (me == SERVER) ? conversation_data->server_state : conversation_data->client_state;
p_add_proto_data(wmem_file_scope(), pinfo, hfi_rsync->id, 0, rsync_frame_data_p);
}
if (me == SERVER) {
switch (rsync_frame_data_p->state) {
case RSYNC_SERV_INIT:
dissect_rsync_version_header(tvb, pinfo, rsync_tree, me);
conversation_data->server_state = RSYNC_SERV_MOTD;
break;
case RSYNC_SERV_MOTD:
proto_tree_add_item(rsync_tree, &hfi_rsync_motd_string, tvb, offset, -1, ENC_ASCII|ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Server MOTD");
conversation_data->server_state = RSYNC_SERV_MOTD;
break;
case RSYNC_MODULE_LIST:
/* there are two cases - file list, or authentication */
if (0 == tvb_strneql(tvb, offset, RSYNCD_AUTHREQD, RSYNCD_AUTHREQD_LEN)) {
/* matches, so we assume it's an authentication message */
proto_tree_add_item(rsync_tree, &hfi_rsync_rsyncdok_string, tvb, offset, -1, ENC_ASCII|ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Authentication");
conversation_data->server_state = RSYNC_DATA;
} else { /* it didn't match, so it is probably a module list */
proto_tree_add_item(rsync_tree, &hfi_rsync_module_list_string, tvb, offset, -1, ENC_ASCII|ENC_NA);
/* we need to check the end of the buffer for magic string */
buff_length = tvb_captured_length_remaining(tvb, offset);
if (buff_length > RSYNCD_EXIT_LEN &&
0 == tvb_strneql(tvb, buff_length-RSYNCD_EXIT_LEN-1, RSYNCD_EXIT, RSYNCD_EXIT_LEN)) {
/* that's all, folks */
col_set_str(pinfo->cinfo, COL_INFO, "Final module list");
conversation_data->server_state = RSYNC_DATA;
} else { /* there must be more data */
col_set_str(pinfo->cinfo, COL_INFO, "Module list");
conversation_data->server_state = RSYNC_MODULE_LIST;
}
}
break;
case RSYNC_DATA:
proto_tree_add_item(rsync_tree, &hfi_rsync_data, tvb, offset, -1, ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Data");
conversation_data->server_state = RSYNC_DATA;
break;
default:
/* Unknown state */
break;
}
} else { /* me == CLIENT */
switch (rsync_frame_data_p->state) {
case RSYNC_INIT:
dissect_rsync_version_header(tvb, pinfo, rsync_tree, me);
conversation_data->client_state = RSYNC_CLIENT_QUERY;
break;
case RSYNC_CLIENT_QUERY:
proto_tree_add_item(rsync_tree, &hfi_rsync_query_string, tvb, offset, -1, ENC_ASCII|ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Client Query");
conversation_data->client_state = RSYNC_COMMAND;
if (tvb_captured_length(tvb) == RSYNC_MODULE_LIST_QUERY_LEN &&
0 == tvb_strneql(tvb, offset, RSYNC_MODULE_LIST_QUERY, RSYNC_MODULE_LIST_QUERY_LEN)) {
conversation_data->server_state = RSYNC_MODULE_LIST;
} else {
conversation_data->server_state = RSYNC_DATA;
}
break;
case RSYNC_COMMAND:
/* then we are still sending commands */
proto_tree_add_item(rsync_tree, &hfi_rsync_command_string, tvb, offset, -1, ENC_ASCII|ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Client Command");
conversation_data->client_state = RSYNC_COMMAND;
break;
case RSYNC_DATA:
/* then we are still sending commands */
proto_tree_add_item(rsync_tree, &hfi_rsync_data, tvb, offset, -1, ENC_NA);
col_set_str(pinfo->cinfo, COL_INFO, "Data");
conversation_data->client_state = RSYNC_DATA;
break;
default:
/* Unknown state */
break;
}
}
return tvb_captured_length(tvb);
}
/* Packet dissection routine called by tcp (& udp) when port 873 detected */
static int
dissect_rsync(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_rsync_encap(tvb, pinfo, tree, rsync_desegment);
}
/* Register protocol with Wireshark. */
void proto_reg_handoff_rsync(void);
void
proto_register_rsync(void)
{
#ifndef HAVE_HFI_SECTION_INIT
static header_field_info *hfi[] = {
&hfi_rsync_hdr_magic,
&hfi_rsync_hdr_version,
&hfi_rsync_query_string,
&hfi_rsync_module_list_string,
&hfi_rsync_motd_string,
&hfi_rsync_rsyncdok_string,
&hfi_rsync_command_string,
&hfi_rsync_data,
};
#endif
static gint *ett[] = {
&ett_rsync,
};
module_t *rsync_module;
int proto_rsync;
proto_rsync = proto_register_protocol("RSYNC File Synchroniser",
"RSYNC", "rsync");
hfi_rsync = proto_registrar_get_nth(proto_rsync);
proto_register_fields(proto_rsync, hfi, array_length(hfi));
proto_register_subtree_array(ett, array_length(ett));
rsync_module = prefs_register_protocol(proto_rsync, proto_reg_handoff_rsync);
prefs_register_uint_preference(rsync_module, "tcp_port",
"rsync TCP Port",
"Set the TCP port for RSYNC messages",
10,
&glb_rsync_tcp_port);
prefs_register_bool_preference(rsync_module, "desegment",
"Reassemble RSYNC messages spanning multiple TCP segments",
"Whether the RSYNC dissector should reassemble messages spanning multiple TCP segments."
" To use this option, you must also enable"
" \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
&rsync_desegment);
rsync_handle = create_dissector_handle(dissect_rsync, proto_rsync);
}
void
proto_reg_handoff_rsync(void)
{
static gboolean initialized = FALSE;
static guint saved_rsync_tcp_port;
if (!initialized) {
initialized = TRUE;
} else {
dissector_delete_uint("tcp.port", saved_rsync_tcp_port, rsync_handle);
}
dissector_add_uint("tcp.port", glb_rsync_tcp_port, rsync_handle);
saved_rsync_tcp_port = glb_rsync_tcp_port;
}
/*
* Editor modelines - http://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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