wireshark/packet-eth.c

128 lines
4.0 KiB
C

/* packet-eth.c
* Routines for ethernet packet disassembly
*
* $Id: packet-eth.c,v 1.2 1998/09/16 03:22:04 gerald Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <gtk/gtk.h>
#include <stdio.h>
#include <pcap.h>
#include "packet.h"
#include "ethereal.h"
#include "etypes.h"
/* These are the Netware-ish names for the different Ethernet frame types.
EthernetII: The ethernet with a Type field instead of a length field
Ethernet802.2: An 802.3 header followed by an 802.3 header
Ethernet802.3: A raw 802.3 packet. IPX/SPX can be the only payload.
There's not 802.2 hdr in this.
EthernetSNAP: Basically 802.2, just with 802.2SNAP. For our purposes,
there's no difference between 802.2 and 802.2SNAP, since we just
pass it down to dissect_llc(). -- Gilbert
*/
#define ETHERNET_II 0
#define ETHERNET_802_2 1
#define ETHERNET_802_3 2
#define ETHERNET_SNAP 3
void
dissect_eth(const u_char *pd, frame_data *fd, GtkTree *tree) {
guint16 etype, length;
int offset = 14;
GtkWidget *fh_tree, *ti;
int ethhdr_type; /* the type of ethernet frame */
if (fd->win_info[0]) {
strcpy(fd->win_info[2], ether_to_str((guint8 *)&pd[0]));
strcpy(fd->win_info[1], ether_to_str((guint8 *)&pd[6]));
strcpy(fd->win_info[4], "Ethernet II");
}
etype = (pd[12] << 8) | pd[13];
/* either ethernet802.3 or ethernet802.2 */
if (etype <= IEEE_802_3_MAX_LEN) {
length = etype;
/* Is there an 802.2 layer? I can tell by looking at the first 2
bytes after the 802.3 header. If they are 0xffff, then what
follows the 802.3 header is an IPX payload, meaning no 802.2.
(IPX/SPX is they only thing that can be contained inside a
straight 802.3 packet). A non-0xffff value means that there's an
802.2 layer inside the 802.3 layer */
if (pd[14] == 0xff && pd[15] == 0xff) {
ethhdr_type = ETHERNET_802_3;
}
else {
ethhdr_type = ETHERNET_802_2;
}
if (fd->win_info[0]) { sprintf(fd->win_info[4], "802.3"); }
if (tree) {
ti = add_item_to_tree(GTK_WIDGET(tree), 0, offset,
"IEEE 802.3 %s(%d on wire, %d captured)",
(ethhdr_type == ETHERNET_802_3 ? "Raw " : ""),
fd->pkt_len, fd->cap_len);
fh_tree = gtk_tree_new();
add_subtree(ti, fh_tree, ETT_IEEE8023);
add_item_to_tree(fh_tree, 0, 6, "Destination: %s",
ether_to_str((guint8 *) &pd[0]));
add_item_to_tree(fh_tree, 6, 6, "Source: %s",
ether_to_str((guint8 *) &pd[6]));
add_item_to_tree(fh_tree, 12, 2, "Length: %d", length);
}
} else if (tree) {
ethhdr_type = ETHERNET_II;
ti = add_item_to_tree(GTK_WIDGET(tree), 0, 14,
"Ethernet II (%d on wire, %d captured)", fd->pkt_len, fd->cap_len);
fh_tree = gtk_tree_new();
add_subtree(ti, fh_tree, ETT_ETHER2);
add_item_to_tree(fh_tree, 0, 6, "Destination: %s",
ether_to_str((guint8 *) &pd[0]));
add_item_to_tree(fh_tree, 6, 6, "Source: %s",
ether_to_str((guint8 *) &pd[6]));
}
/* either ethernet802.3 or ethernet802.2 */
switch (ethhdr_type) {
case ETHERNET_802_3:
dissect_ipx(pd, offset, fd, tree);
return;
case ETHERNET_802_2:
dissect_llc(pd, offset, fd, tree);
return;
}
/* Ethernet_II */
ethertype(etype, offset, pd, fd, tree, fh_tree);
}