![Michael Mann](/assets/img/avatar_default.png)
Change-Id: If862aadbd483933782d5979a3c0be2cb3c08a480 Reviewed-on: https://code.wireshark.org/review/12481 Reviewed-by: Michael Mann <mmann78@netscape.net>
361 lines
14 KiB
C
361 lines
14 KiB
C
/* packet-PROTOABBREV.c
|
|
* Routines for PROTONAME dissection
|
|
* Copyright 201x, YOUR_NAME <YOUR_EMAIL_ADDRESS>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* (A short description of the protocol including links to specifications,
|
|
* detailed documentation, etc.)
|
|
*/
|
|
|
|
#include <config.h>
|
|
|
|
#if 0
|
|
/* "System" includes used only as needed */
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
...
|
|
#endif
|
|
|
|
#include <epan/packet.h> /* Should be first Wireshark include (other than config.h) */
|
|
#include <epan/expert.h> /* Include only as needed */
|
|
#include <epan/prefs.h> /* Include only as needed */
|
|
|
|
#if 0
|
|
/* IF AND ONLY IF your protocol dissector exposes code to other dissectors
|
|
* (which most dissectors don't need to do) then the 'public' prototypes and
|
|
* data structures can go in the header file packet-PROTOABBREV.h. If not, then
|
|
* a header file is not needed at all and this #include statement can be
|
|
* removed. */
|
|
#include "packet-PROTOABBREV.h"
|
|
#endif
|
|
|
|
/* Prototypes */
|
|
/* (Required to prevent [-Wmissing-prototypes] warnings */
|
|
void proto_reg_handoff_PROTOABBREV(void);
|
|
void proto_register_PROTOABBREV(void);
|
|
|
|
/* Initialize the protocol and registered fields */
|
|
static int proto_PROTOABBREV = -1;
|
|
static int hf_PROTOABBREV_FIELDABBREV = -1;
|
|
static expert_field ei_PROTOABBREV_EXPERTABBREV = EI_INIT;
|
|
|
|
/* Global sample preference ("controls" display of numbers) */
|
|
static gboolean pref_hex = FALSE;
|
|
/* Global sample port preference - real port preferences should generally
|
|
* default to 0 unless there is an IANA-registered (or equivalent) port for your
|
|
* protocol. */
|
|
#define PROTOABBREV_TCP_PORT 1234
|
|
static guint tcp_port_pref = PROTOABBREV_TCP_PORT;
|
|
|
|
/* Initialize the subtree pointers */
|
|
static gint ett_PROTOABBREV = -1;
|
|
|
|
/* A sample #define of the minimum length (in bytes) of the protocol data.
|
|
* If data is received with fewer than this many bytes it is rejected by
|
|
* the current dissector. */
|
|
#define PROTOABBREV_MIN_LENGTH 8
|
|
|
|
/* Code to actually dissect the packets */
|
|
static int
|
|
dissect_PROTOABBREV(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
|
|
void *data _U_)
|
|
{
|
|
/* Set up structures needed to add the protocol subtree and manage it */
|
|
proto_item *ti, *expert_ti;
|
|
proto_tree *PROTOABBREV_tree;
|
|
/* Other misc. local variables. */
|
|
guint offset = 0;
|
|
int len = 0;
|
|
|
|
/*** HEURISTICS ***/
|
|
|
|
/* First, if at all possible, do some heuristics to check if the packet
|
|
* cannot possibly belong to your protocol. This is especially important
|
|
* for protocols directly on top of TCP or UDP where port collisions are
|
|
* common place (e.g., even though your protocol uses a well known port,
|
|
* someone else may set up, for example, a web server on that port which,
|
|
* if someone analyzed that web server's traffic in Wireshark, would result
|
|
* in Wireshark handing an HTTP packet to your dissector).
|
|
*
|
|
* For example:
|
|
*/
|
|
|
|
/* Check that the packet is long enough for it to belong to us. */
|
|
if (tvb_reported_length(tvb) < PROTOABBREV_MIN_LENGTH)
|
|
return 0;
|
|
|
|
/* Check that there's enough data present to run the heuristics. If there
|
|
* isn't, reject the packet; it will probably be dissected as data and if
|
|
* the user wants it dissected despite it being short they can use the
|
|
* "Decode-As" functionality. If your heuristic needs to look very deep into
|
|
* the packet you may not want to require *all* data to be present, but you
|
|
* should ensure that the heuristic does not access beyond the captured
|
|
* length of the packet regardless. */
|
|
if (tvb_captured_length(tvb) < MAX_NEEDED_FOR_HEURISTICS)
|
|
return 0;
|
|
|
|
/* Fetch some values from the packet header using tvb_get_*(). If these
|
|
* values are not valid/possible in your protocol then return 0 to give
|
|
* some other dissector a chance to dissect it. */
|
|
if ( TEST_HEURISTICS_FAIL )
|
|
return 0;
|
|
|
|
/*** COLUMN DATA ***/
|
|
|
|
/* There are two normal columns to fill in: the 'Protocol' column which
|
|
* is narrow and generally just contains the constant string 'PROTOABBREV',
|
|
* and the 'Info' column which can be much wider and contain misc. summary
|
|
* information (for example, the port number for TCP packets).
|
|
*
|
|
* If you are setting the column to a constant string, use "col_set_str()",
|
|
* as it's more efficient than the other "col_set_XXX()" calls.
|
|
*
|
|
* If
|
|
* - you may be appending to the column later OR
|
|
* - you have constructed the string locally OR
|
|
* - the string was returned from a call to val_to_str()
|
|
* then use "col_add_str()" instead, as that takes a copy of the string.
|
|
*
|
|
* The function "col_add_fstr()" can be used instead of "col_add_str()"; it
|
|
* takes "printf()"-like arguments. Don't use "col_add_fstr()" with a format
|
|
* string of "%s" - just use "col_add_str()" or "col_set_str()", as it's
|
|
* more efficient than "col_add_fstr()".
|
|
*
|
|
* For full details see section 1.4 of README.dissector.
|
|
*/
|
|
|
|
/* Set the Protocol column to the constant string of PROTOABBREV */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PROTOABBREV");
|
|
|
|
#if 0
|
|
/* If you will be fetching any data from the packet before filling in
|
|
* the Info column, clear that column first in case the calls to fetch
|
|
* data from the packet throw an exception so that the Info column doesn't
|
|
* contain data left over from the previous dissector: */
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
#endif
|
|
|
|
col_set_str(pinfo->cinfo, COL_INFO, "XXX Request");
|
|
|
|
/*** PROTOCOL TREE ***/
|
|
|
|
/* Now we will create a sub-tree for our protocol and start adding fields
|
|
* to display under that sub-tree. Most of the time the only functions you
|
|
* will need are proto_tree_add_item() and proto_item_add_subtree().
|
|
*
|
|
* NOTE: The offset and length values in the call to proto_tree_add_item()
|
|
* define what data bytes to highlight in the hex display window when the
|
|
* line in the protocol tree display corresponding to that item is selected.
|
|
*
|
|
* Supplying a length of -1 tells Wireshark to highlight all data from the
|
|
* offset to the end of the packet.
|
|
*/
|
|
|
|
/* create display subtree for the protocol */
|
|
ti = proto_tree_add_item(tree, proto_PROTOABBREV, tvb, 0, -1, ENC_NA);
|
|
|
|
PROTOABBREV_tree = proto_item_add_subtree(ti, ett_PROTOABBREV);
|
|
|
|
/* Add an item to the subtree, see section 1.5 of README.dissector for more
|
|
* information. */
|
|
expert_ti = proto_tree_add_item(PROTOABBREV_tree, hf_PROTOABBREV_FIELDABBREV, tvb,
|
|
offset, len, ENC_xxx);
|
|
offset += len;
|
|
/* Some fields or situations may require "expert" analysis that can be
|
|
* specifically highlighted. */
|
|
if ( TEST_EXPERT_condition )
|
|
/* value of hf_PROTOABBREV_FIELDABBREV isn't what's expected */
|
|
expert_add_info(pinfo, expert_ti, &ei_PROTOABBREV_EXPERTABBREV);
|
|
|
|
/* Continue adding tree items to process the packet here... */
|
|
|
|
/* If this protocol has a sub-dissector call it here, see section 1.8 of
|
|
* README.dissector for more information. */
|
|
|
|
/* Return the amount of data this dissector was able to dissect (which may
|
|
* or may not be the total captured packet as we return here). */
|
|
return tvb_captured_length(tvb);
|
|
}
|
|
|
|
/* Register the protocol with Wireshark.
|
|
*
|
|
* This format is require because a script is used to build the C function that
|
|
* calls all the protocol registration.
|
|
*/
|
|
void
|
|
proto_register_PROTOABBREV(void)
|
|
{
|
|
module_t *PROTOABBREV_module;
|
|
expert_module_t *expert_PROTOABBREV;
|
|
|
|
/* Setup list of header fields See Section 1.5 of README.dissector for
|
|
* details. */
|
|
static hf_register_info hf[] = {
|
|
{ &hf_PROTOABBREV_FIELDABBREV,
|
|
{ "FIELDNAME", "PROTOABBREV.FIELDABBREV",
|
|
FT_FIELDTYPE, FIELDDISPLAY, FIELDCONVERT, BITMASK,
|
|
"FIELDDESCR", HFILL }
|
|
}
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_PROTOABBREV
|
|
};
|
|
|
|
/* Setup protocol expert items */
|
|
static ei_register_info ei[] = {
|
|
{ &ei_PROTOABBREV_EXPERTABBREV,
|
|
{ "PROTOABBREV.EXPERTABBREV", PI_SEVERITY, PI_GROUP,
|
|
"EXPERTDESCR", EXPFILL }
|
|
}
|
|
};
|
|
|
|
/* Register the protocol name and description */
|
|
proto_PROTOABBREV = proto_register_protocol("PROTONAME",
|
|
"PROTOSHORTNAME", "PROTOABBREV");
|
|
|
|
/* Required function calls to register the header fields and subtrees */
|
|
proto_register_field_array(proto_PROTOABBREV, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
/* Required function calls to register expert items */
|
|
expert_PROTOABBREV = expert_register_protocol(proto_PROTOABBREV);
|
|
expert_register_field_array(expert_PROTOABBREV, ei, array_length(ei));
|
|
|
|
/* Register a preferences module (see section 2.6 of README.dissector
|
|
* for more details). Registration of a prefs callback is not required
|
|
* if there are no preferences that affect protocol registration (an example
|
|
* of a preference that would affect registration is a port preference).
|
|
* If the prefs callback is not needed, use NULL instead of
|
|
* proto_reg_handoff_PROTOABBREV in the following.
|
|
*/
|
|
PROTOABBREV_module = prefs_register_protocol(proto_PROTOABBREV,
|
|
proto_reg_handoff_PROTOABBREV);
|
|
|
|
/* Register a preferences module under the preferences subtree.
|
|
* Only use this function instead of prefs_register_protocol (above) if you
|
|
* want to group preferences of several protocols under one preferences
|
|
* subtree.
|
|
*
|
|
* Argument subtree identifies grouping tree node name, several subnodes can
|
|
* be specified using slash '/' (e.g. "OSI/X.500" - protocol preferences
|
|
* will be accessible under Protocols->OSI->X.500-><PROTOSHORTNAME>
|
|
* preferences node.
|
|
*/
|
|
PROTOABBREV_module = prefs_register_protocol_subtree(const char *subtree,
|
|
proto_PROTOABBREV, proto_reg_handoff_PROTOABBREV);
|
|
|
|
/* Register a simple example preference */
|
|
prefs_register_bool_preference(PROTOABBREV_module, "show_hex",
|
|
"Display numbers in Hex",
|
|
"Enable to display numerical values in hexadecimal.",
|
|
&pref_hex);
|
|
|
|
/* Register an example port preference */
|
|
prefs_register_uint_preference(PROTOABBREV_module, "tcp.port", "PROTOABBREV TCP Port",
|
|
" PROTOABBREV TCP port if other than the default",
|
|
10, &tcp_port_pref);
|
|
}
|
|
|
|
/* If this dissector uses sub-dissector registration add a registration routine.
|
|
* This exact format is required because a script is used to find these
|
|
* routines and create the code that calls these routines.
|
|
*
|
|
* If this function is registered as a prefs callback (see
|
|
* prefs_register_protocol above) this function is also called by Wireshark's
|
|
* preferences manager whenever "Apply" or "OK" are pressed. In that case, it
|
|
* should accommodate being called more than once by use of the static
|
|
* 'initialized' variable included below.
|
|
*
|
|
* This form of the reg_handoff function is used if if you perform registration
|
|
* functions which are dependent upon prefs. See below this function for a
|
|
* simpler form which can be used if there are no prefs-dependent registration
|
|
* functions.
|
|
*/
|
|
void
|
|
proto_reg_handoff_PROTOABBREV(void)
|
|
{
|
|
static gboolean initialized = FALSE;
|
|
static dissector_handle_t PROTOABBREV_handle;
|
|
static int current_port;
|
|
|
|
if (!initialized) {
|
|
/* Use create_dissector_handle() to indicate that
|
|
* dissect_PROTOABBREV() returns the number of bytes it dissected (or 0
|
|
* if it thinks the packet does not belong to PROTONAME).
|
|
*/
|
|
PROTOABBREV_handle = create_dissector_handle(dissect_PROTOABBREV,
|
|
proto_PROTOABBREV);
|
|
initialized = TRUE;
|
|
|
|
} else {
|
|
/* If you perform registration functions which are dependent upon
|
|
* prefs then you should de-register everything which was associated
|
|
* with the previous settings and re-register using the new prefs
|
|
* settings here. In general this means you need to keep track of
|
|
* the PROTOABBREV_handle and the value the preference had at the time
|
|
* you registered. The PROTOABBREV_handle value and the value of the
|
|
* preference can be saved using local statics in this
|
|
* function (proto_reg_handoff).
|
|
*/
|
|
dissector_delete_uint("tcp.port", current_port, PROTOABBREV_handle);
|
|
}
|
|
|
|
current_port = tcp_port_pref;
|
|
|
|
dissector_add_uint("tcp.port", current_port, PROTOABBREV_handle);
|
|
}
|
|
|
|
#if 0
|
|
|
|
/* Simpler form of proto_reg_handoff_PROTOABBREV which can be used if there are
|
|
* no prefs-dependent registration function calls. */
|
|
void
|
|
proto_reg_handoff_PROTOABBREV(void)
|
|
{
|
|
dissector_handle_t PROTOABBREV_handle;
|
|
|
|
/* Use create_dissector_handle() to indicate that dissect_PROTOABBREV()
|
|
* returns the number of bytes it dissected (or 0 if it thinks the packet
|
|
* does not belong to PROTONAME).
|
|
*/
|
|
PROTOABBREV_handle = create_dissector_handle(dissect_PROTOABBREV,
|
|
proto_PROTOABBREV);
|
|
dissector_add_uint("tcp.port", PROTOABBREV_TCP_PORT, PROTOABBREV_handle);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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:
|
|
*/
|