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wireshark/epan/dissectors/packet-finger.c
Michael Mann 268841f3e0 Combine Decode As and port preferences for tcp.port dissector table. 
This patch introduces new APIs to allow dissectors to have a preference for
a (TCP) port, but the underlying data is actually part of Decode As functionality.
For now the APIs are intentionally separate from the regular APIs that register a
dissector within a dissector table.  It may be possible to eventually combine the
two so that all dissectors that register with a dissector table have an opportunity
to "automatically" have a preference to adjust the "table value" through the
preferences dialog.

The tcp.port dissector table was used as the guinea pig.  This will eventually be
expanded to other dissector tables as well (most notably UDP ports).  Some
dissectors that "shared" a TCP/UDP port preference were also converted. It also
removed the need for some preference callback functions (mostly when the callback
function was the proto_reg_handoff function) so there is cleanup around that.

Dissectors that has a port preference whose default was 0 were switched to using
the dissector_add_for_decode_as_with_preference API rather than dissector_add_uint_with_preference

Also added comments for TCP ports used that aren't IANA registered.

Change-Id: I99604f95d426ad345f4b494598d94178b886eb67
Reviewed-on: https://code.wireshark.org/review/17724
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-10-08 02:44:53 +00:00

221 lines
7.6 KiB
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/* packet-finger.c
* Routines for basic finger dissection (see http://tools.ietf.org/html/rfc742)
* Copyright 2013, Christopher Maynard <Christopher.Maynard@gtech.com>
*
* 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.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/conversation.h>
#include <epan/expert.h>
void proto_register_finger(void);
void proto_reg_handoff_finger(void);
#define FINGER_PORT 79 /* This is the registered IANA port */
static int proto_finger = -1;
static int hf_finger_query = -1;
static int hf_finger_response = -1;
static int hf_finger_response_in = -1;
static int hf_finger_response_to = -1;
static int hf_finger_response_time = -1;
static expert_field ei_finger_nocrlf = EI_INIT;
static gint ett_finger = -1;
typedef struct _finger_transaction_t {
guint32 req_frame;
guint32 rep_frame;
nstime_t req_time;
} finger_transaction_t;
static int
dissect_finger(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
void *data _U_)
{
proto_item *ti, *expert_ti;
proto_tree *finger_tree;
conversation_t *conversation;
finger_transaction_t *finger_trans;
gboolean is_query;
guint len;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "FINGER");
if (pinfo->destport == FINGER_PORT) {
is_query = TRUE;
col_set_str(pinfo->cinfo, COL_INFO, "Query");
} else {
is_query = FALSE;
col_set_str(pinfo->cinfo, COL_INFO, "Response");
}
conversation = find_or_create_conversation(pinfo);
finger_trans = (finger_transaction_t *)conversation_get_proto_data(conversation, proto_finger);
if (finger_trans == NULL) {
finger_trans = wmem_new0(wmem_file_scope(), finger_transaction_t);
conversation_add_proto_data(conversation, proto_finger, finger_trans);
}
len = tvb_reported_length(tvb);
if (!PINFO_FD_VISITED(pinfo)) {
if (pinfo->can_desegment) {
if (is_query) {
if ((len < 2) || (tvb_memeql(tvb, len - 2, "\r\n", 2))) {
pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
pinfo->desegment_offset = 0;
return -1;
} else {
finger_trans->req_frame = pinfo->num;
finger_trans->req_time = pinfo->abs_ts;
}
} else {
pinfo->desegment_len = DESEGMENT_UNTIL_FIN;
pinfo->desegment_offset = 0;
return -1;
}
}
} else if (is_query && (finger_trans->req_frame == 0)) {
finger_trans->req_frame = pinfo->num;
finger_trans->req_time = pinfo->abs_ts;
}
if (!is_query && (finger_trans->rep_frame == 0)) {
/* By comparing finger_trans->rep_frame to 0, if reassembly is turned
* on, finger_trans->rep_frame will be assigned to the reassembled frame
* number, and if reassembly is turned off, finger_trans->rep_frame will
* be assigned to the first frame number of the response. This seems
* to match other protocols' behavior. The alternative is:
* if (pinfo->num > finger_trans->rep_frame)
* which will give us the same frame number either way.
*/
finger_trans->rep_frame = pinfo->num;
}
ti = proto_tree_add_protocol_format(tree, proto_finger, tvb, 0, -1,
"FINGER: %s", is_query ? "Query" : "Response");
finger_tree = proto_item_add_subtree(ti, ett_finger);
if (is_query) {
expert_ti = proto_tree_add_item(finger_tree, hf_finger_query, tvb, 0, -1, ENC_ASCII|ENC_NA);
if ((len < 2) || (tvb_memeql(tvb, len - 2, "\r\n", 2))) {
/*
* From RFC742, Send a single "command line", ending with <CRLF>.
*/
expert_add_info(pinfo, expert_ti, &ei_finger_nocrlf);
}
if (tree && finger_trans->rep_frame) {
ti = proto_tree_add_uint(finger_tree, hf_finger_response_in,
tvb, 0, 0, finger_trans->rep_frame);
PROTO_ITEM_SET_GENERATED(ti);
}
} else if (tree && finger_trans->rep_frame) {
proto_tree_add_item(finger_tree, hf_finger_response, tvb, 0, -1, ENC_ASCII|ENC_NA);
if (finger_trans->req_frame) {
nstime_t ns;
ti = proto_tree_add_uint(finger_tree, hf_finger_response_to,
tvb, 0, 0, finger_trans->req_frame);
PROTO_ITEM_SET_GENERATED(ti);
if (pinfo->num == finger_trans->rep_frame) {
nstime_delta(&ns, &pinfo->abs_ts, &finger_trans->req_time);
ti = proto_tree_add_time(finger_tree, hf_finger_response_time, tvb, 0, 0, &ns);
PROTO_ITEM_SET_GENERATED(ti);
}
}
}
return tvb_captured_length(tvb);
}
void
proto_register_finger(void)
{
expert_module_t *expert_finger;
static hf_register_info hf[] = {
{ &hf_finger_query,
{ "Query", "finger.query", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_finger_response,
{ "Response", "finger.response", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_finger_response_in,
{ "Response In", "finger.response_in", FT_FRAMENUM, BASE_NONE, NULL,
0x0, "The response to this FINGER query is in this frame",
HFILL }
},
{ &hf_finger_response_to,
{ "Request In", "finger.response_to", FT_FRAMENUM, BASE_NONE, NULL,
0x0, "This is a response to the FINGER query in this frame",
HFILL }
},
{ &hf_finger_response_time,
{ "Response Time", "finger.response_time", FT_RELATIVE_TIME,
BASE_NONE, NULL, 0x0,
"The time between the Query and the Response", HFILL }
}
};
static gint *ett[] = {
&ett_finger
};
static ei_register_info ei[] = {
{ &ei_finger_nocrlf,
{ "finger.nocrlf", PI_MALFORMED, PI_WARN, "Missing <CR><LF>", EXPFILL}
}
};
proto_finger = proto_register_protocol("finger", "FINGER", "finger");
proto_register_field_array(proto_finger, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_finger = expert_register_protocol(proto_finger);
expert_register_field_array(expert_finger, ei, array_length(ei));
}
void
proto_reg_handoff_finger(void)
{
static dissector_handle_t finger_handle;
finger_handle = create_dissector_handle(dissect_finger, proto_finger);
dissector_add_uint_with_preference("tcp.port", FINGER_PORT, finger_handle);
}
/*
* 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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