/* 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);
}