![Guy Harris](/assets/img/avatar_default.png)
length field rather than an Ethernet type field) into a "dissect_802_3()" routine. In that routine, catch exceptions thrown by the IPX or LLC dissector or dissectors under them, so that the trailer information is added to the tree even if an exception is thrown (similar to what "ethertype()" does). svn path=/trunk/; revision=3002
171 lines
4.8 KiB
C
171 lines
4.8 KiB
C
/* packet-vlan.c
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* Routines for VLAN 802.1Q ethernet header disassembly
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*
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* $Id: packet-vlan.c,v 1.33 2001/02/08 07:08:05 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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# include <netinet/in.h>
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#endif
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#include <glib.h>
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#include "packet.h"
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#include "packet-ieee8023.h"
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#include "packet-ipx.h"
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#include "packet-llc.h"
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#include "etypes.h"
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static int proto_vlan = -1;
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static int hf_vlan_priority = -1;
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static int hf_vlan_cfi = -1;
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static int hf_vlan_id = -1;
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static int hf_vlan_etype = -1;
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static int hf_vlan_len = -1;
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static int hf_vlan_trailer = -1;
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static gint ett_vlan = -1;
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void
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capture_vlan(const u_char *pd, int offset, packet_counts *ld ) {
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guint16 encap_proto;
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if ( !BYTES_ARE_IN_FRAME(offset,5) ) {
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ld->other++;
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return;
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}
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encap_proto = pntohs( &pd[offset+2] );
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if ( encap_proto <= IEEE_802_3_MAX_LEN) {
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if ( pd[offset+4] == 0xff && pd[offset+5] == 0xff ) {
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capture_ipx(pd,offset+4,ld);
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} else {
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capture_llc(pd,offset+4,ld);
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}
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} else {
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capture_ethertype(encap_proto, offset+4, pd, ld);
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}
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}
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static void
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dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *ti;
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guint16 tci,encap_proto;
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volatile gboolean is_802_2;
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proto_tree *volatile vlan_tree;
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if (check_col(pinfo->fd, COL_PROTOCOL))
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col_set_str(pinfo->fd, COL_PROTOCOL, "VLAN");
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if (check_col(pinfo->fd, COL_INFO))
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col_clear(pinfo->fd, COL_INFO);
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tci = tvb_get_ntohs( tvb, 0 );
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if (check_col(pinfo->fd, COL_INFO)) {
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col_add_fstr(pinfo->fd, COL_INFO, "PRI: %d CFI: %d ID: %d",
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(tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF));
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}
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vlan_tree = NULL;
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if (tree) {
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ti = proto_tree_add_item(tree, proto_vlan, tvb, 0, 4, FALSE);
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vlan_tree = proto_item_add_subtree(ti, ett_vlan);
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proto_tree_add_uint(vlan_tree, hf_vlan_priority, tvb, 0, 2, tci);
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proto_tree_add_uint(vlan_tree, hf_vlan_cfi, tvb, 0, 2, tci);
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proto_tree_add_uint(vlan_tree, hf_vlan_id, tvb, 0, 2, tci);
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}
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encap_proto = tvb_get_ntohs(tvb, 2);
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if (encap_proto <= IEEE_802_3_MAX_LEN) {
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/* Is there an 802.2 layer? I can tell by looking at the first 2
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bytes after the VLAN header. If they are 0xffff, then what
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follows the VLAN header is an IPX payload, meaning no 802.2.
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(IPX/SPX is they only thing that can be contained inside a
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straight 802.3 packet, so presumably the same applies for
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Ethernet VLAN packets). A non-0xffff value means that there's an
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802.2 layer inside the VLAN layer */
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is_802_2 = TRUE;
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TRY {
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if (tvb_get_ntohs(tvb, 4) == 0xffff) {
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is_802_2 = FALSE;
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}
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}
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CATCH2(BoundsError, ReportedBoundsError) {
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; /* do nothing */
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}
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ENDTRY;
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dissect_802_3(encap_proto, is_802_2, tvb, 4, pinfo, tree, vlan_tree,
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hf_vlan_len, hf_vlan_trailer);
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} else {
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ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree,
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hf_vlan_etype, hf_vlan_trailer);
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}
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}
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void
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proto_register_vlan(void)
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{
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static hf_register_info hf[] = {
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{ &hf_vlan_priority, {
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"Priority", "vlan.priority", FT_UINT16, BASE_BIN,
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0, 0xE000, "Priority" }},
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{ &hf_vlan_cfi, {
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"CFI", "vlan.cfi", FT_UINT16, BASE_BIN,
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0, 0x1000, "CFI" }}, /* XXX - Boolean? */
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{ &hf_vlan_id, {
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"ID", "vlan.id", FT_UINT16, BASE_BIN,
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0, 0x0FFF, "ID" }},
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{ &hf_vlan_etype, {
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"Type", "vlan.etype", FT_UINT16, BASE_HEX,
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VALS(etype_vals), 0x0, "Type" }},
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{ &hf_vlan_len, {
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"Length", "vlan.len", FT_UINT16, BASE_DEC,
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NULL, 0x0, "Length" }},
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{ &hf_vlan_trailer, {
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"Trailer", "vlan.trailer", FT_BYTES, BASE_NONE,
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NULL, 0x0, "VLAN Trailer" }}
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};
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static gint *ett[] = {
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&ett_vlan,
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};
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proto_vlan = proto_register_protocol("802.1q Virtual LAN", "VLAN", "vlan");
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proto_register_field_array(proto_vlan, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_vlan(void)
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{
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dissector_add("ethertype", ETHERTYPE_VLAN, dissect_vlan, proto_vlan);
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}
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