wireshark/packet-frame.c

/* packet-frame.c
 *
 * Top-most dissector. Decides dissector based on Wiretap Encapsulation Type.
 *
 * $Id: packet-frame.c,v 1.32 2002/10/31 07:12:23 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 2000 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/timestamp.h>
#include <epan/tvbuff.h>
#include "packet-frame.h"
#include "prefs.h"
#include "tap.h"

static int proto_frame = -1;
static int hf_frame_arrival_time = -1;
static int hf_frame_time_delta = -1;
static int hf_frame_time_relative = -1;
static int hf_frame_number = -1;
static int hf_frame_packet_len = -1;
static int hf_frame_capture_len = -1;
static int hf_frame_p2p_dir = -1;
static int hf_frame_file_off = -1;
static int hf_frame_marked = -1;

static int proto_short = -1;
int proto_malformed = -1;
static int proto_unreassembled = -1;

static gint ett_frame = -1;

static int frame_tap = -1;

static dissector_handle_t data_handle;
static dissector_handle_t docsis_handle;

/* Preferences */
static gboolean show_file_off = FALSE;
static gboolean force_docsis_encap;

static const value_string p2p_dirs[] = {
	{ P2P_DIR_SENT,	"Sent" },
	{ P2P_DIR_RECV, "Received" },
	{ 0, NULL }
};

static dissector_table_t wtap_encap_dissector_table;

static void
dissect_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	proto_tree	*fh_tree;
	proto_item	*ti;
	nstime_t	ts;
	int		cap_len, pkt_len;

	pinfo->current_proto = "Frame";

	if (pinfo->pseudo_header != NULL) {
		switch (pinfo->fd->lnk_t) {

		case WTAP_ENCAP_CHDLC:
		case WTAP_ENCAP_PPP_WITH_PHDR:
			pinfo->p2p_dir = pinfo->pseudo_header->p2p.sent ?
			    P2P_DIR_SENT : P2P_DIR_RECV;
			break;

		case WTAP_ENCAP_LAPB:
		case WTAP_ENCAP_FRELAY:
			pinfo->p2p_dir =
			    (pinfo->pseudo_header->x25.flags & FROM_DCE) ?
			    P2P_DIR_RECV : P2P_DIR_SENT;
			break;

		case WTAP_ENCAP_ISDN:
			pinfo->p2p_dir = pinfo->pseudo_header->isdn.uton ?
			    P2P_DIR_SENT : P2P_DIR_RECV;
			break;
		}
	}

	if ((force_docsis_encap) && (docsis_handle)) {
		/*
		 * XXX - setting it here makes it impossible to
		 * turn the "Treat all frames as DOCSIS frames"
		 * option off.
		 *
		 * The TCP Graph code currently uses "fd->lnk_t";
		 * it should eventually just get the information
		 * it needs from a full-blown dissection, so that
		 * can handle any link-layer type.
		 */
		pinfo->fd->lnk_t = WTAP_ENCAP_DOCSIS;
	}

	/* Put in frame header information. */
	if (tree) {

	  cap_len = tvb_length(tvb);
	  pkt_len = tvb_reported_length(tvb);

	  ti = proto_tree_add_protocol_format(tree, proto_frame, tvb, 0, -1,
	    "Frame %u (%u bytes on wire, %u bytes captured)", pinfo->fd->num, pkt_len, cap_len);

	  fh_tree = proto_item_add_subtree(ti, ett_frame);

	  proto_tree_add_boolean_hidden(fh_tree, hf_frame_marked, tvb, 0, 0,pinfo->fd->flags.marked);

	  ts.secs = pinfo->fd->abs_secs;
	  ts.nsecs = pinfo->fd->abs_usecs*1000;

	  proto_tree_add_time(fh_tree, hf_frame_arrival_time, tvb,
		0, 0, &ts);

	  ts.secs = pinfo->fd->del_secs;
	  ts.nsecs = pinfo->fd->del_usecs*1000;

	  proto_tree_add_time(fh_tree, hf_frame_time_delta, tvb,
		0, 0, &ts);

	  ts.secs = pinfo->fd->rel_secs;
	  ts.nsecs = pinfo->fd->rel_usecs*1000;

	  proto_tree_add_time(fh_tree, hf_frame_time_relative, tvb,
		0, 0, &ts);

	  proto_tree_add_uint(fh_tree, hf_frame_number, tvb,
		0, 0, pinfo->fd->num);

	  proto_tree_add_uint_format(fh_tree, hf_frame_packet_len, tvb,
		0, 0, pkt_len, "Packet Length: %d byte%s", pkt_len,
		plurality(pkt_len, "", "s"));

	  proto_tree_add_uint_format(fh_tree, hf_frame_capture_len, tvb,
		0, 0, cap_len, "Capture Length: %d byte%s", cap_len,
		plurality(cap_len, "", "s"));

	  /* Check for existences of P2P pseudo header */
	  if (pinfo->p2p_dir != P2P_DIR_UNKNOWN) {
		  proto_tree_add_uint(fh_tree, hf_frame_p2p_dir, tvb,
				  0, 0, pinfo->p2p_dir);
	  }

	  if (show_file_off) {
		  proto_tree_add_int_format(fh_tree, hf_frame_file_off, tvb,
				  0, 0, pinfo->fd->file_off,
				  "File Offset: %ld (0x%lx)",
				  pinfo->fd->file_off, pinfo->fd->file_off);
	  }
	}


	TRY {
		if (!dissector_try_port(wtap_encap_dissector_table, pinfo->fd->lnk_t,
					tvb, pinfo, tree)) {

			if (check_col(pinfo->cinfo, COL_PROTOCOL))
				col_set_str(pinfo->cinfo, COL_PROTOCOL, "UNKNOWN");
			if (check_col(pinfo->cinfo, COL_INFO))
				col_add_fstr(pinfo->cinfo, COL_INFO, "WTAP_ENCAP = %u",
				    pinfo->fd->lnk_t);
			call_dissector(data_handle,tvb, pinfo, tree);
		}
	}
	CATCH(BoundsError) {
		if (check_col(pinfo->cinfo, COL_INFO))
			col_append_str(pinfo->cinfo, COL_INFO, "[Short Frame]");
		proto_tree_add_protocol_format(tree, proto_short, tvb, 0, 0,
				"[Short Frame: %s]", pinfo->current_proto);
	}
	CATCH(ReportedBoundsError) {
		show_reported_bounds_error(tvb, pinfo, tree);
	}
	ENDTRY;

	tap_queue_packet(frame_tap, pinfo, NULL);
}

void
show_reported_bounds_error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	if (pinfo->fragmented) {
		/*
		 * We were dissecting an unreassembled fragmented
		 * packet when the exception was thrown, so the
		 * problem isn't that the dissector expected
		 * something but it wasn't in the packet, the
		 * problem is that the dissector expected something
		 * but it wasn't in the fragment we dissected.
		 */
		if (check_col(pinfo->cinfo, COL_INFO))
			col_append_str(pinfo->cinfo, COL_INFO,
			    "[Unreassembled Packet]");
		proto_tree_add_protocol_format(tree, proto_unreassembled,
		    tvb, 0, 0, "[Unreassembled Packet: %s]",
		    pinfo->current_proto);
	} else {
		if (check_col(pinfo->cinfo, COL_INFO))
			col_append_str(pinfo->cinfo, COL_INFO,
			    "[Malformed Packet]");
		proto_tree_add_protocol_format(tree, proto_malformed,
		    tvb, 0, 0, "[Malformed Packet: %s]", pinfo->current_proto);
	}
}

void
proto_register_frame(void)
{
	static hf_register_info hf[] = {
		{ &hf_frame_arrival_time,
		{ "Arrival Time",		"frame.time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0,
			"", HFILL }},

		{ &hf_frame_time_delta,
		{ "Time delta from previous packet",	"frame.time_delta", FT_RELATIVE_TIME, BASE_NONE, NULL,
			0x0,
			"", HFILL }},

		{ &hf_frame_time_relative,
		{ "Time relative to first packet",	"frame.time_relative", FT_RELATIVE_TIME, BASE_NONE, NULL,
			0x0,
			"", HFILL }},

		{ &hf_frame_number,
		{ "Frame Number",		"frame.number", FT_UINT32, BASE_DEC, NULL, 0x0,
			"", HFILL }},

		{ &hf_frame_packet_len,
		{ "Total Frame Length",		"frame.pkt_len", FT_UINT32, BASE_DEC, NULL, 0x0,
			"", HFILL }},

		{ &hf_frame_capture_len,
		{ "Capture Frame Length",	"frame.cap_len", FT_UINT32, BASE_DEC, NULL, 0x0,
			"", HFILL }},

		{ &hf_frame_p2p_dir,
		{ "Point-to-Point Direction",	"frame.p2p_dir", FT_UINT8, BASE_DEC, VALS(p2p_dirs), 0x0,
			"", HFILL }},

		{ &hf_frame_file_off,
		{ "File Offset",	"frame.file_off", FT_INT32, BASE_DEC, NULL, 0x0,
			"", HFILL }},

		{ &hf_frame_marked,
		{ "Frame is marked",	"frame.marked", FT_BOOLEAN, 8, NULL, 0x0,
			"Frame is marked in the GUI", HFILL }},
	};
	static gint *ett[] = {
		&ett_frame,
	};
	module_t *frame_module;

	wtap_encap_dissector_table = register_dissector_table("wtap_encap",
	    "Wiretap encapsulation type", FT_UINT32, BASE_DEC);

	proto_frame = proto_register_protocol("Frame", "Frame", "frame");
	proto_register_field_array(proto_frame, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
	register_dissector("frame",dissect_frame,proto_frame);

	/* You can't disable dissection of "Frame", as that would be
	   tantamount to not doing any dissection whatsoever. */
	proto_set_cant_disable(proto_frame);

	proto_short = proto_register_protocol("Short Frame", "Short frame", "short");
	proto_malformed = proto_register_protocol("Malformed Packet",
	    "Malformed packet", "malformed");
	proto_unreassembled = proto_register_protocol(
	    "Unreassembled Fragmented Packet",
	    "Unreassembled fragmented packet", "unreassembled");

	/* "Short Frame", "Malformed Packet", and "Unreassembled Fragmented
	   Packet" aren't really protocols, they're error indications;
	   disabling them makes no sense. */
	proto_set_cant_disable(proto_short);
	proto_set_cant_disable(proto_malformed);
	proto_set_cant_disable(proto_unreassembled);

	/* Our preferences */
	frame_module = prefs_register_protocol(proto_frame, NULL);
	prefs_register_bool_preference(frame_module, "show_file_off",
	    "Show File Offset", "Show File Offset", &show_file_off);
	prefs_register_bool_preference(frame_module, "force_docsis_encap",
	    "Treat all frames as DOCSIS frames", "Treat all frames as DOCSIS Frames", &force_docsis_encap);

	frame_tap=register_tap("frame");
}

void
proto_reg_handoff_frame(void)
{
	data_handle = find_dissector("data");
	docsis_handle = find_dissector("docsis");
}