2aa31bea47
"etypes.h". svn path=/trunk/; revision=3314
321 lines
9.8 KiB
C
321 lines
9.8 KiB
C
/* packet-eth.c
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* Routines for ethernet packet disassembly
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*
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* $Id: packet-eth.c,v 1.64 2001/04/17 06:43:18 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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#include <glib.h>
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#include "packet.h"
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#include "etypes.h"
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#include "resolv.h"
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#include "packet-eth.h"
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#include "packet-ieee8023.h"
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#include "packet-ipx.h"
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#include "packet-isl.h"
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#include "packet-llc.h"
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/* protocols and header fields */
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static int proto_eth = -1;
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static int hf_eth_dst = -1;
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static int hf_eth_src = -1;
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static int hf_eth_len = -1;
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static int hf_eth_type = -1;
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static int hf_eth_addr = -1;
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static int hf_eth_trailer = -1;
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static gint ett_ieee8023 = -1;
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static gint ett_ether2 = -1;
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static dissector_handle_t isl_handle;
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#define ETH_HEADER_SIZE 14
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/* These are the Netware-ish names for the different Ethernet frame types.
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EthernetII: The ethernet with a Type field instead of a length field
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Ethernet802.2: An 802.3 header followed by an 802.2 header
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Ethernet802.3: A raw 802.3 packet. IPX/SPX can be the only payload.
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There's no 802.2 hdr in this.
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EthernetSNAP: Basically 802.2, just with 802.2SNAP. For our purposes,
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there's no difference between 802.2 and 802.2SNAP, since we just
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pass it down to the LLC dissector. -- Gilbert
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*/
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#define ETHERNET_II 0
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#define ETHERNET_802_2 1
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#define ETHERNET_802_3 2
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#define ETHERNET_SNAP 3
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void
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capture_eth(const u_char *pd, int offset, packet_counts *ld)
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{
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guint16 etype, length;
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int ethhdr_type; /* the type of ethernet frame */
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if (!BYTES_ARE_IN_FRAME(offset, ETH_HEADER_SIZE)) {
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ld->other++;
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return;
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}
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etype = pntohs(&pd[offset+12]);
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/* either ethernet802.3 or ethernet802.2 */
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if (etype <= IEEE_802_3_MAX_LEN) {
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length = etype;
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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 802.3 header. If they are 0xffff, then what
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follows the 802.3 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). A non-0xffff value means that there's an
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802.2 layer inside the 802.3 layer */
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if (pd[offset+14] == 0xff && pd[offset+15] == 0xff) {
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ethhdr_type = ETHERNET_802_3;
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}
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else {
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ethhdr_type = ETHERNET_802_2;
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}
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/* Oh, yuck. Cisco ISL frames require special interpretation of the
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destination address field; fortunately, they can be recognized by
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checking the first 5 octets of the destination address, which are
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01-00-0C-00-00 for ISL frames. */
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if (pd[offset] == 0x01 && pd[offset+1] == 0x00 && pd[offset+2] == 0x0C
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&& pd[offset+3] == 0x00 && pd[offset+4] == 0x00) {
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capture_isl(pd, offset, ld);
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return;
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}
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/* Convert the LLC length from the 802.3 header to a total
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frame length, by adding in the size of any data that preceded
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the Ethernet header, and adding in the Ethernet header size,
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and set the payload and captured-payload lengths to the minima
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of the total length and the frame lengths. */
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length += offset + ETH_HEADER_SIZE;
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if (pi.len > length)
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pi.len = length;
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if (pi.captured_len > length)
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pi.captured_len = length;
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} else {
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ethhdr_type = ETHERNET_II;
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}
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offset += ETH_HEADER_SIZE;
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switch (ethhdr_type) {
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case ETHERNET_802_3:
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capture_ipx(pd, offset, ld);
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break;
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case ETHERNET_802_2:
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capture_llc(pd, offset, ld);
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break;
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case ETHERNET_II:
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capture_ethertype(etype, offset, pd, ld);
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break;
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}
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}
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static void
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dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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int orig_captured_len;
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proto_item *ti;
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const guint8 *dst, *src;
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const guint8 *pd;
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guint16 etype;
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volatile gboolean is_802_2;
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int eth_offset;
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volatile guint16 length;
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proto_tree *volatile fh_tree = NULL;
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tvb_compat(tvb, &pd, (int*)ð_offset);
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orig_captured_len = pinfo->captured_len;
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if (check_col(pinfo->fd, COL_PROTOCOL))
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col_set_str(pinfo->fd, COL_PROTOCOL, "Ethernet");
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src = tvb_get_ptr(tvb, 6, 6);
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dst = tvb_get_ptr(tvb, 0, 6);
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SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src);
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SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src);
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SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, dst);
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SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, dst);
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etype = tvb_get_ntohs(tvb, 12);
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/* either ethernet802.3 or ethernet802.2 */
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if (etype <= IEEE_802_3_MAX_LEN) {
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length = etype;
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/* Oh, yuck. Cisco ISL frames require special interpretation of the
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destination address field; fortunately, they can be recognized by
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checking the first 5 octets of the destination address, which are
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01-00-0C-00-00 for ISL frames. */
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if ( tvb_get_guint8(tvb, 0) == 0x01 &&
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tvb_get_guint8(tvb, 1) == 0x00 &&
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tvb_get_guint8(tvb, 2) == 0x0C &&
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tvb_get_guint8(tvb, 3) == 0x00 &&
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tvb_get_guint8(tvb, 4) == 0x00 ) {
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call_dissector(isl_handle, tvb, pinfo, tree);
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return;
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}
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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 802.3 header. If they are 0xffff, then what
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follows the 802.3 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). A non-0xffff value means that there's an
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802.2 layer inside the 802.3 layer */
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is_802_2 = TRUE;
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TRY {
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if (tvb_get_ntohs(tvb, 14) == 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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if (check_col(pinfo->fd, COL_INFO)) {
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col_add_fstr(pinfo->fd, COL_INFO, "IEEE 802.3 Ethernet %s",
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(is_802_2 ? "" : "Raw "));
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}
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
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"IEEE 802.3 Ethernet %s", (is_802_2 ? "" : "Raw "));
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fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
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proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
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proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
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/* add items for eth.addr filter */
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proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
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proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
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}
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/* Convert the LLC length from the 802.3 header to a total
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frame length, by adding in the size of any data that preceded
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the Ethernet header, and adding in the Ethernet header size,
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and set the payload and captured-payload lengths to the minima
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of the total length and the frame lengths.
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XXX - when all dissectors are tvbuffified we shouldn't have to
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do this any more. */
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length += eth_offset + ETH_HEADER_SIZE;
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if (pinfo->len > length)
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pinfo->len = length;
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if (pinfo->captured_len > length)
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pinfo->captured_len = length;
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dissect_802_3(etype, is_802_2, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree,
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hf_eth_len, hf_eth_trailer);
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} else {
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if (check_col(pinfo->fd, COL_INFO))
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col_set_str(pinfo->fd, COL_INFO, "Ethernet II");
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
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"Ethernet II");
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fh_tree = proto_item_add_subtree(ti, ett_ether2);
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proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
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proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
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/* add items for eth.addr filter */
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proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
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proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
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}
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ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_eth_type,
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hf_eth_trailer);
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}
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}
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void
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proto_register_eth(void)
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{
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static hf_register_info hf[] = {
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{ &hf_eth_dst,
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{ "Destination", "eth.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
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"Destination Hardware Address" }},
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{ &hf_eth_src,
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{ "Source", "eth.src", FT_ETHER, BASE_NONE, NULL, 0x0,
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"Source Hardware Address" }},
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{ &hf_eth_len,
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{ "Length", "eth.len", FT_UINT16, BASE_DEC, NULL, 0x0,
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"" }},
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/* registered here but handled in ethertype.c */
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{ &hf_eth_type,
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{ "Type", "eth.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
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"" }},
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{ &hf_eth_addr,
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{ "Source or Destination Address", "eth.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
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"Source or Destination Hardware Address" }},
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{ &hf_eth_trailer,
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{ "Trailer", "eth.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
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"Ethernet Trailer or Checksum" }},
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};
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static gint *ett[] = {
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&ett_ieee8023,
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&ett_ether2,
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};
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proto_eth = proto_register_protocol("Ethernet", "Ethernet", "eth");
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proto_register_field_array(proto_eth, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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register_dissector("eth", dissect_eth, proto_eth);
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}
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void
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proto_reg_handoff_eth(void)
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{
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/*
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* Get a handle for the ISL dissector.
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*/
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isl_handle = find_dissector("isl");
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dissector_add("wtap_encap", WTAP_ENCAP_ETHERNET, dissect_eth,
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proto_eth);
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dissector_add("ethertype", ETHERTYPE_ETHBRIDGE, dissect_eth,
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proto_eth);
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dissector_add("chdlctype", ETHERTYPE_ETHBRIDGE, dissect_eth,
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proto_eth);
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dissector_add("gre.proto", ETHERTYPE_ETHBRIDGE, dissect_eth,
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proto_eth);
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}
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