wireshark/packet-fw1.c
Guy Harris be2736adcf Have a pseudo-header for Ethernet packets, giving the size of the FCS -
0 means "there is no FCS in the packet data", 4 means "there is an FCS
in the packet data", -1 means "I don't know whether there's an FCS in
the packet data, guess based on the packet size".

Assume that Ethernet encapsulated inside other protocols has no FCS, by
having the "eth" dissector assume that (and not check for an Ethernet
pseudo-header).

Have "ethertype()" take an argument giving the FCS size; pass 0 when
appropriate.

Fix up Wiretap routines to set the pseudo-header.  This means we no
longer use the "generic" seek-and-read routine, so get rid of it.

svn path=/trunk/; revision=8574
2003-10-01 07:11:49 +00:00

298 lines
9.6 KiB
C

/* packet-fw1.c
* Routines for Ethernet header disassembly of FW1 "monitor" files
* Copyright 2002,2003, Alfred Koebler <ako@icon.de>
*
* $Id: packet-fw1.c,v 1.9 2003/10/01 07:11:44 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Alfred Koebler <ako@icon.de>
* Copyright 2002,2003 Alfred Koebler
*
* To use this dissector use the command line option
* -o eth.interpret_as_fw1_monitor:TRUE
*
* At the moment the way with the option is the best one.
* A automatic way is not possible, because the file format isn't different
* to the snoop file.
*
* With "fw monitor" it is possible to collect packets on several places.
* The additional information:
* - is it a incoming or outgoing packet
* - is it before or after the firewall
* i incoming before the firewall
* I incoming after the firewall
* o outcoming before the firewall
* O outcoming after the firewall
* - the name of the interface
*
* What's the problem ?
* Think about one packet traveling across the firewall.
* With ethereal you will see 4 lines in the Top Pane.
* To analyze a problem it is helpful to see the additional information
* in the protocol tree of the Middle Pane.
*
* The presentation of the summary line is designed in the following way:
* Every time the next selected packet in the Top Pane includes a
* "new" interface name the name is added to the list in the summary line.
* The interface names are listed one after the other.
* The position of the interface names didn't change.
*
* And who are the 4 places represented ?
* The interface name represents the firewall module of the interface.
* On the left side of the interface name is the interface module.
* On the right side of the interface name is the "IP" module.
*
* Example for a ping from the firewall to another host:
* For the four lines in the Top Pane you will see the according lines
* in the Middle Pane:
* El90x1 o
* O El90x1
* i El90x1
* El90x1 I
*
* Example for a packet traversing through the Firewall, first through
* the inner side firewall module then through the outer side firewall module:
* i El90x1 El90x2
* El90x1 I El90x2
* El90x1 o E190x2
* El90x1 E190x2 O
*
* 9.12.2002
* Add new column with summary of FW-1 interface/direction
*
* 11.8.2003
* Additional interpretation of field Chain Position.
* Show the chain position in the interface list.
* Support for new format of fw monitor file
* writen by option -u | -s for UUID/SUUID.
* NOTICE: First paket will have UUID == 0 !
*
* 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 <string.h>
#include <glib.h>
#include <epan/packet.h>
#include "prefs.h"
#include "etypes.h"
/* Place FW1 summary in proto tree */
static gboolean fw1_summary_in_tree = TRUE;
static gboolean fw1_with_uuid = FALSE;
static gboolean fw1_iflist_with_chain = FALSE;
/* Initialize the protocol and registered fields */
static int proto_fw1 = -1;
static int hf_fw1_direction = -1;
static int hf_fw1_chain = -1;
static int hf_fw1_interface = -1;
static int hf_fw1_uuid = -1;
static int hf_fw1_type = -1;
static int hf_fw1_trailer = -1;
/* Initialize the subtree pointers */
static gint ett_fw1 = -1;
#define ETH_HEADER_SIZE 14
static dissector_handle_t eth_handle;
static void
dissect_fw1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
/* Set up structures needed to add the protocol subtree and manage it */
proto_item *ti;
proto_tree *volatile fh_tree = NULL;
char direction[3];
char chain[3];
char interface_name[10+1];
guint32 uuid;
guint16 etype;
char header[1000];
char *p_header;
int i;
int found;
#define MAX_INTERFACES 20
static char *p_interfaces[MAX_INTERFACES];
static int interface_anzahl=0;
static char header1[] = "FW1 Monitor";
#ifdef DID_NOT_FIND_A_PLACE_TO_START_THE_RESET_LIST_OF_INTERFACES
if (fw1_reset_list_of_if_on_next_begin) {
/* without FW1 summary delete all remembered names of interfaces */
for (i=0; i<interface_anzahl && i<MAX_INTERFACES; i++) {
free(p_interfaces[i]);
}
interface_anzahl = 0;
fw1_reset_list_of_if_on_next_begin = FALSE;
}
#endif
/* Make entries in Protocol column and Info column on summary display */
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "FW1");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
etype = tvb_get_ntohs(tvb, 12);
sprintf(header, header1);
/* fetch info to local variable */
direction[0] = tvb_get_guint8(tvb, 0);
direction[1] = 0;
chain[0] = tvb_get_guint8(tvb, 1);
chain[1] = 0;
if (!fw1_with_uuid) {
tvb_get_nstringz0(tvb, 2, 6, interface_name);
uuid = 0;
} else {
tvb_get_nstringz0(tvb, 2, sizeof interface_name, interface_name);
uuid = tvb_get_ntohl(tvb, 8);
}
/* Known interface name - if not, remember it */
found=1;
for (i=0; i<interface_anzahl && i<MAX_INTERFACES; i++) {
if ( strcmp(p_interfaces[i], interface_name) == 0 ) {
found=0;
}
}
if (found == 1 ) {
p_interfaces[interface_anzahl] = strdup(interface_name);
interface_anzahl++;
}
/* display all interfaces always in the same order */
for (i=0; i<interface_anzahl; i++) {
found=1;
if ( strcmp(p_interfaces[i], interface_name) == 0 ) {
found=0;
}
p_header = header + strlen(header);
if (!fw1_iflist_with_chain) {
sprintf(p_header, " %c %s %c",
found==0 ? (direction[0]=='i' ? 'i' : (direction[0]=='O' ? 'O' : ' ')) : ' ',
p_interfaces[i],
found==0 ? (direction[0]=='I' ? 'I' : (direction[0]=='o' ? 'o' : ' ')) : ' '
);
} else {
sprintf(p_header, " %c%c %s %c%c",
found==0 ? (direction[0]=='i' ? 'i' : (direction[0]=='O' ? 'O' : ' ')) : ' ',
found==0 ? (direction[0]=='i' ? chain[0] : (direction[0]=='O' ? chain[0] : ' ')) : ' ',
p_interfaces[i],
found==0 ? (direction[0]=='I' ? 'I' : (direction[0]=='o' ? 'o' : ' ')) : ' ',
found==0 ? (direction[0]=='I' ? chain[0] : (direction[0]=='o' ? chain[0] : ' ')) : ' '
);
}
}
if (check_col(pinfo->cinfo, COL_IF_DIR))
col_add_str(pinfo->cinfo, COL_IF_DIR, header + strlen(header1) + 1);
if (tree) {
if (!fw1_summary_in_tree) {
/* Do not show the summary in Protocol Tree */
sprintf(header, header1);
}
ti = proto_tree_add_protocol_format(tree, proto_fw1, tvb, 0, ETH_HEADER_SIZE, header);
/* create display subtree for the protocol */
fh_tree = proto_item_add_subtree(ti, ett_fw1);
proto_tree_add_item(fh_tree, hf_fw1_direction, tvb, 0, 1, FALSE);
proto_tree_add_item(fh_tree, hf_fw1_chain, tvb, 1, 1, FALSE);
if (!fw1_with_uuid) {
proto_tree_add_string_format(fh_tree, hf_fw1_interface,
tvb, 2, 10,
interface_name, "Interface: %s", interface_name);
} else {
proto_tree_add_string_format(fh_tree, hf_fw1_interface,
tvb, 2, 6,
interface_name, "Interface: %s", interface_name);
proto_tree_add_item(fh_tree, hf_fw1_uuid, tvb, 8, 4, FALSE);
}
}
ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_fw1_type,
hf_fw1_trailer, 0);
}
void
proto_register_fw1(void)
{
static hf_register_info hf[] = {
{ &hf_fw1_direction,
{ "Direction", "fw1.direction", FT_STRING, BASE_NONE, NULL, 0x0,
"Direction", HFILL }},
{ &hf_fw1_chain,
{ "Chain Position", "fw1.chain", FT_STRING, BASE_NONE, NULL, 0x0,
"Chain Position", HFILL }},
{ &hf_fw1_interface,
{ "Interface", "fw1.interface", FT_STRING, BASE_NONE, NULL, 0x0,
"Interface", HFILL }},
{ &hf_fw1_uuid,
{ "UUID", "fw1.uuid", FT_UINT32, BASE_DEC, NULL, 0x0,
"UUID", HFILL }},
/* registered here but handled in ethertype.c */
{ &hf_fw1_type,
{ "Type", "fw1.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
"", HFILL }},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_fw1,
};
module_t *fw1_module;
/* Register the protocol name and description */
proto_fw1 = proto_register_protocol("Checkpoint FW-1", "FW-1", "fw1");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_fw1, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* Register configuration preferences */
fw1_module = prefs_register_protocol(proto_fw1, NULL);
prefs_register_bool_preference(fw1_module, "summary_in_tree",
"Show FireWall-1 summary in protocol tree",
"Whether the FireWall-1 summary line should be shown in the protocol tree",
&fw1_summary_in_tree);
prefs_register_bool_preference(fw1_module, "with_uuid",
"fw monitor file includes UUID",
"Whether the fw monitor file includes information of UUID",
&fw1_with_uuid);
prefs_register_bool_preference(fw1_module, "iflist_with_chain",
"Interface list with chain position",
"Whether the interface list includes chain position",
&fw1_iflist_with_chain);
register_dissector("fw1", dissect_fw1, proto_fw1);
}
void
proto_reg_handoff_fw1(void)
{
/*
* Get handles for the Ethernet dissectors.
*/
eth_handle = find_dissector("eth");
}