/* packet-eth.c
* Routines for ethernet packet disassembly
*
- * $Id: packet-eth.c,v 1.46 2000/11/13 05:28:00 guy Exp $
+ * $Id: packet-eth.c,v 1.85 2003/08/26 05:52:44 guy Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
* 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.
# include "config.h"
#endif
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
#include <glib.h>
-#include "packet.h"
+#include <epan/packet.h>
+#include "prefs.h"
#include "etypes.h"
-#include "resolv.h"
+#include <epan/resolv.h>
#include "packet-eth.h"
+#include "packet-ieee8023.h"
#include "packet-ipx.h"
#include "packet-isl.h"
#include "packet-llc.h"
+#include "crc32.h"
+#include "tap.h"
-extern const value_string etype_vals[];
+/* Interpret capture file as FW1 monitor file */
+static gboolean eth_interpret_as_fw1_monitor = FALSE;
/* protocols and header fields */
static int proto_eth = -1;
static gint ett_ieee8023 = -1;
static gint ett_ether2 = -1;
+static dissector_handle_t isl_handle;
+static dissector_handle_t fw1_handle;
+
+static int eth_tap = -1;
+
#define ETH_HEADER_SIZE 14
/* 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 802.2 header
Ethernet802.3: A raw 802.3 packet. IPX/SPX can be the only payload.
- There's not 802.2 hdr in this.
+ There's no 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
+ pass it down to the LLC dissector. -- Gilbert
*/
#define ETHERNET_II 0
#define ETHERNET_802_2 1
#define ETHERNET_SNAP 3
void
-capture_eth(const u_char *pd, int offset, packet_counts *ld)
+capture_eth(const guchar *pd, int offset, int len, packet_counts *ld)
{
guint16 etype, length;
int ethhdr_type; /* the type of ethernet frame */
- if (!BYTES_ARE_IN_FRAME(offset, ETH_HEADER_SIZE)) {
+ if (!BYTES_ARE_IN_FRAME(offset, len, ETH_HEADER_SIZE)) {
ld->other++;
return;
}
-
+
etype = pntohs(&pd[offset+12]);
- /* either ethernet802.3 or ethernet802.2 */
- if (etype <= IEEE_802_3_MAX_LEN) {
+ /*
+ * If the type/length field is <= the maximum 802.3 length,
+ * and is not zero, this is an 802.3 frame, and it's a length
+ * field; it might be an Novell "raw 802.3" frame, with no
+ * 802.2 LLC header, or it might be a frame with an 802.2 LLC
+ * header.
+ *
+ * If the type/length field is > the maximum 802.3 length,
+ * this is an Ethernet II frame, and it's a type field.
+ *
+ * If the type/length field is zero (ETHERTYPE_UNK), this is
+ * a frame used internally by the Cisco MDS switch to contain
+ * Fibre Channel ("Vegas"). We treat that as an Ethernet II
+ * frame; the dissector for those frames registers itself with
+ * an ethernet type of ETHERTYPE_UNK.
+ */
+ if (etype <= IEEE_802_3_MAX_LEN && etype != ETHERTYPE_UNK) {
length = etype;
/* Is there an 802.2 layer? I can tell by looking at the first 2
01-00-0C-00-00 for ISL frames. */
if (pd[offset] == 0x01 && pd[offset+1] == 0x00 && pd[offset+2] == 0x0C
&& pd[offset+3] == 0x00 && pd[offset+4] == 0x00) {
- capture_isl(pd, offset, ld);
+ capture_isl(pd, offset, len, ld);
return;
}
and set the payload and captured-payload lengths to the minima
of the total length and the frame lengths. */
length += offset + ETH_HEADER_SIZE;
- if (pi.len > length)
- pi.len = length;
- if (pi.captured_len > length)
- pi.captured_len = length;
+ if (len > length)
+ len = length;
} else {
ethhdr_type = ETHERNET_II;
}
switch (ethhdr_type) {
case ETHERNET_802_3:
- capture_ipx(pd, offset, ld);
+ capture_ipx(ld);
break;
case ETHERNET_802_2:
- capture_llc(pd, offset, ld);
+ capture_llc(pd, offset, len, ld);
break;
case ETHERNET_II:
- capture_ethertype(etype, offset, pd, ld);
+ capture_ethertype(etype, pd, offset, len, ld);
break;
}
}
-void
+static void
dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
- int orig_captured_len;
proto_item *ti;
- guint8 *dst, *src;
- const guint8 *pd;
-
- volatile guint16 etype;
- volatile int ethhdr_type; /* the type of Ethernet frame */
- volatile int eth_offset;
- volatile guint16 length;
- tvbuff_t *volatile next_tvb;
- tvbuff_t *volatile trailer_tvb;
- proto_tree *volatile fh_tree;
-
- CHECK_DISPLAY_AS_DATA(proto_eth, tvb, pinfo, tree);
-
- tvb_compat(tvb, &pd, (int*)ð_offset);
-
- pinfo->current_proto = "Ethernet";
- orig_captured_len = pinfo->captured_len;
-
- if (check_col(pinfo->fd, COL_PROTOCOL))
- col_add_str(pinfo->fd, COL_PROTOCOL, "Ethernet");
-
- src = tvb_get_ptr(tvb, 6, 6);
- dst = tvb_get_ptr(tvb, 0, 6);
- SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src);
- SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src);
- SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, dst);
- SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, dst);
-
- etype = tvb_get_ntohs(tvb, 12);
-
- /* either ethernet802.3 or ethernet802.2 */
- if (etype <= IEEE_802_3_MAX_LEN) {
- length = etype;
+ eth_hdr *ehdr;
+ volatile gboolean is_802_2;
+ proto_tree *volatile fh_tree = NULL;
+ const char *src_addr, *dst_addr;
+ static eth_hdr ehdrs[4];
+ static int ehdr_num=0;
+
+ ehdr_num++;
+ if(ehdr_num>=4){
+ ehdr_num=0;
+ }
+ ehdr=&ehdrs[ehdr_num];
+
+
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "Ethernet");
+
+ src_addr=tvb_get_ptr(tvb, 6, 6);
+ SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src_addr);
+ SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src_addr);
+ SET_ADDRESS(&ehdr->src, AT_ETHER, 6, src_addr);
+ dst_addr=tvb_get_ptr(tvb, 0, 6);
+ SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, dst_addr);
+ SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, dst_addr);
+ SET_ADDRESS(&ehdr->dst, AT_ETHER, 6, dst_addr);
+
+ ehdr->type = tvb_get_ntohs(tvb, 12);
+
+ /*
+ * If the type/length field is <= the maximum 802.3 length,
+ * and is not zero, this is an 802.3 frame, and it's a length
+ * field; it might be an Novell "raw 802.3" frame, with no
+ * 802.2 LLC header, or it might be a frame with an 802.2 LLC
+ * header.
+ *
+ * If the type/length field is > the maximum 802.3 length,
+ * this is an Ethernet II frame, and it's a type field.
+ *
+ * If the type/length field is zero (ETHERTYPE_UNK), this is
+ * a frame used internally by the Cisco MDS switch to contain
+ * Fibre Channel ("Vegas"). We treat that as an Ethernet II
+ * frame; the dissector for those frames registers itself with
+ * an ethernet type of ETHERTYPE_UNK.
+ */
+ if (ehdr->type <= IEEE_802_3_MAX_LEN && ehdr->type != ETHERTYPE_UNK) {
+ /* Oh, yuck. Cisco ISL frames require special interpretation of the
+ destination address field; fortunately, they can be recognized by
+ checking the first 5 octets of the destination address, which are
+ 01-00-0C-00-00 for ISL frames. */
+ if ( tvb_get_guint8(tvb, 0) == 0x01 &&
+ tvb_get_guint8(tvb, 1) == 0x00 &&
+ tvb_get_guint8(tvb, 2) == 0x0C &&
+ tvb_get_guint8(tvb, 3) == 0x00 &&
+ tvb_get_guint8(tvb, 4) == 0x00 ) {
+ call_dissector(isl_handle, tvb, pinfo, tree);
+ goto end_of_eth;
+ }
/* 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
(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 */
- ethhdr_type = ETHERNET_802_2;
+ is_802_2 = TRUE;
TRY {
if (tvb_get_ntohs(tvb, 14) == 0xffff) {
- ethhdr_type = ETHERNET_802_3;
+ is_802_2 = FALSE;
}
}
CATCH2(BoundsError, ReportedBoundsError) {
}
ENDTRY;
- /* Oh, yuck. Cisco ISL frames require special interpretation of the
- destination address field; fortunately, they can be recognized by
- checking the first 5 octets of the destination address, which are
- 01-00-0C-00-00 for ISL frames. */
- if ( tvb_get_guint8(tvb, 0) == 0x01 &&
- tvb_get_guint8(tvb, 1) == 0x00 &&
- tvb_get_guint8(tvb, 2) == 0x0C &&
- tvb_get_guint8(tvb, 3) == 0x00 &&
- tvb_get_guint8(tvb, 4) == 0x00 ) {
- dissect_isl(pd, eth_offset, pinfo->fd, tree);
- return;
- }
-
- if (check_col(pinfo->fd, COL_INFO)) {
- col_add_fstr(pinfo->fd, COL_INFO, "IEEE 802.3 %s",
- (ethhdr_type == ETHERNET_802_3 ? "Raw " : ""));
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_add_fstr(pinfo->cinfo, COL_INFO, "IEEE 802.3 Ethernet %s",
+ (is_802_2 ? "" : "Raw "));
}
if (tree) {
+ ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+ "IEEE 802.3 Ethernet %s", (is_802_2 ? "" : "Raw "));
- ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
- "IEEE 802.3 %s", (ethhdr_type == ETHERNET_802_3 ? "Raw " : ""));
-
- fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
+ fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
+ }
- proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
- proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
+ proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst_addr);
+ proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src_addr);
/* add items for eth.addr filter */
- proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
- proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
+ proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst_addr);
+ proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src_addr);
- proto_tree_add_uint(fh_tree, hf_eth_len, tvb, 12, 2, length);
+ dissect_802_3(ehdr->type, is_802_2, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree,
+ hf_eth_len, hf_eth_trailer);
+ } else {
+ if (eth_interpret_as_fw1_monitor) {
+ call_dissector(fw1_handle, tvb, pinfo, tree);
+ goto end_of_eth;
}
- /* Convert the LLC length from the 802.3 header to a total
- frame length, by adding in the size of any data that preceded
- the Ethernet header, and adding in the Ethernet header size,
- and set the payload and captured-payload lengths to the minima
- of the total length and the frame lengths. */
- length += eth_offset + ETH_HEADER_SIZE;
- if (pi.len > length)
- pi.len = length;
- if (pi.captured_len > length)
- pi.captured_len = length;
- } else {
- ethhdr_type = ETHERNET_II;
- if (check_col(pinfo->fd, COL_INFO))
- col_add_str(pinfo->fd, COL_INFO, "Ethernet II");
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_set_str(pinfo->cinfo, COL_INFO, "Ethernet II");
if (tree) {
+ ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+ "Ethernet II, Src: %s, Dst: %s",
+ ether_to_str(src_addr), ether_to_str(dst_addr));
- ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
- "Ethernet II");
-
- fh_tree = proto_item_add_subtree(ti, ett_ether2);
+ fh_tree = proto_item_add_subtree(ti, ett_ether2);
+ }
- proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst);
- proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src);
+ proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst_addr);
+ proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src_addr);
/* add items for eth.addr filter */
- proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst);
- proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src);
- }
- }
- eth_offset += ETH_HEADER_SIZE;
-
- /* Give the next dissector only 'length' number of bytes */
- if (etype <= IEEE_802_3_MAX_LEN) {
- TRY {
- next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, etype, etype);
- trailer_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE + etype, -1, -1);
- }
- CATCH2(BoundsError, ReportedBoundsError) {
- /* Either:
-
- the packet doesn't have "etype" bytes worth of
- captured data left in it - or it may not even have
- "etype" bytes worth of data in it, period -
- so the "tvb_new_subset()" creating "next_tvb"
- threw an exception
-
- or
-
- the packet has exactly "etype" bytes worth of
- captured data left in it, so the "tvb_new_subset()"
- creating "trailer_tvb" threw an exception.
-
- In either case, this means that all the data in the frame
- is within the length value, so we give all the data to the
- next protocol and have no trailer. */
- next_tvb = tvb_new_subset(tvb, ETH_HEADER_SIZE, -1, etype);
- trailer_tvb = NULL;
- }
- ENDTRY;
- }
- else {
- next_tvb = NULL; /* "ethertype()" will create the next tvb for us */
- trailer_tvb = NULL; /* we don't know how big the trailer is */
- }
+ proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 0, 6, dst_addr);
+ proto_tree_add_ether_hidden(fh_tree, hf_eth_addr, tvb, 6, 6, src_addr);
- switch (ethhdr_type) {
- case ETHERNET_802_3:
- dissect_ipx(next_tvb, pinfo, tree);
- break;
- case ETHERNET_802_2:
- dissect_llc(next_tvb, pinfo, tree);
- break;
- case ETHERNET_II:
- ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_eth_type);
- break;
+ ethertype(ehdr->type, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_eth_type,
+ hf_eth_trailer);
}
- /* If there's some bytes left over, mark them. */
- if (trailer_tvb && tree) {
- int trailer_length;
- const guint8 *ptr;
-
- trailer_length = tvb_length(trailer_tvb);
- if (trailer_length > 0) {
- ptr = tvb_get_ptr(trailer_tvb, 0, trailer_length);
- proto_tree_add_bytes(fh_tree, hf_eth_trailer, tvb, ETH_HEADER_SIZE + etype,
- trailer_length, ptr);
- }
- }
+end_of_eth:
+ tap_queue_packet(eth_tap, pinfo, ehdr);
+ return;
+}
+/*
+ * Add an Ethernet trailer - which, for some captures, might be the FCS
+ * rather than a pad-to-60-bytes trailer.
+ */
+void
+add_ethernet_trailer(proto_tree *fh_tree, int trailer_id, tvbuff_t *tvb,
+ tvbuff_t *trailer_tvb)
+{
+ /* If there're some bytes left over, show those bytes as a trailer.
+
+ However, if the Ethernet frame was claimed to have had 64 or more
+ bytes - i.e., it was at least an FCS worth of data longer than
+ the minimum payload size - assume the last 4 bytes of the trailer
+ are an FCS. */
+ if (trailer_tvb && fh_tree) {
+ guint trailer_length, trailer_reported_length;
+ gboolean has_fcs = FALSE;
+
+ trailer_length = tvb_length(trailer_tvb);
+ trailer_reported_length = tvb_reported_length(trailer_tvb);
+ if (tvb_reported_length(tvb) >= 64) {
+ /* OK, the frame is big enough that, if we have a trailer, it
+ probably includes an FCS; there's no need to pad an Ethernet
+ packet past 60 bytes.
+
+ Do we have enough space in the trailer for an FCS? */
+ if (trailer_reported_length >= 4) {
+ /* Yes, as the claimed trailer length is at least as big as
+ a 4-byte FCS. */
+ if (trailer_length < trailer_reported_length) {
+ /* The packet is claimed to have enough data for a 4-byte FCS,
+ but we didn't capture all of the packet.
+ Slice off the 4-byte FCS from the reported length, and
+ trim the captured length so it's no more than the reported
+ length; that will slice off what of the FCS, if any, is
+ in the captured packet. */
+ trailer_reported_length -= 4;
+ if (trailer_length > trailer_reported_length)
+ trailer_length = trailer_reported_length;
+ has_fcs = TRUE;
+ } else {
+ /* We captured all of the packet, including what appears to
+ be a 4-byte FCS. Slice it off. */
+ trailer_length -= 4;
+ trailer_reported_length -= 4;
+ has_fcs = TRUE;
+ }
+ }
+ }
+ if (trailer_length != 0) {
+ proto_tree_add_item(fh_tree, trailer_id, trailer_tvb, 0,
+ trailer_length, FALSE);
+ }
+ if (has_fcs) {
+ guint32 sent_fcs = tvb_get_ntohl(trailer_tvb, trailer_length);
+ guint32 fcs = crc32_802(tvb_get_ptr(tvb, 0, tvb_length(tvb) - 4),
+ tvb_length(tvb) - 4);
+ if (fcs == sent_fcs) {
+ proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+ "Frane check sequence: 0x%08x (correct)",
+ sent_fcs);
+ } else {
+ proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+ "Frane check sequence: 0x%08x (incorrect, should be 0x%08x)",
+ sent_fcs, fcs);
+ }
+ }
+ }
}
void
{ &hf_eth_dst,
{ "Destination", "eth.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
- "Destination Hardware Address" }},
+ "Destination Hardware Address", HFILL }},
{ &hf_eth_src,
{ "Source", "eth.src", FT_ETHER, BASE_NONE, NULL, 0x0,
- "Source Hardware Address" }},
+ "Source Hardware Address", HFILL }},
{ &hf_eth_len,
{ "Length", "eth.len", FT_UINT16, BASE_DEC, NULL, 0x0,
- "" }},
+ "", HFILL }},
/* registered here but handled in ethertype.c */
{ &hf_eth_type,
{ "Type", "eth.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
- "" }},
+ "", HFILL }},
{ &hf_eth_addr,
{ "Source or Destination Address", "eth.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
- "Source or Destination Hardware Address" }},
+ "Source or Destination Hardware Address", HFILL }},
{ &hf_eth_trailer,
{ "Trailer", "eth.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
- "Ethernet Trailer or Checksum" }},
+ "Ethernet Trailer or Checksum", HFILL }},
};
static gint *ett[] = {
&ett_ieee8023,
&ett_ether2,
};
+ module_t *eth_module;
- proto_eth = proto_register_protocol ("Ethernet", "eth" );
+ proto_eth = proto_register_protocol("Ethernet", "Ethernet", "eth");
proto_register_field_array(proto_eth, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
+
+ /* Register configuration preferences */
+ eth_module = prefs_register_protocol(proto_eth, NULL);
+ prefs_register_bool_preference(eth_module, "interpret_as_fw1_monitor",
+ "Interpret as FireWall-1 monitor file",
+"Whether the capture file should be interpreted as a CheckPoint FireWall-1 monitor file",
+ ð_interpret_as_fw1_monitor);
+
+ register_dissector("eth", dissect_eth, proto_eth);
+ eth_tap = register_tap("eth");
+}
+
+void
+proto_reg_handoff_eth(void)
+{
+ dissector_handle_t eth_handle;
+
+ /*
+ * Get a handle for the ISL dissector.
+ */
+ isl_handle = find_dissector("isl");
+ fw1_handle = find_dissector("fw1");
+
+ eth_handle = find_dissector("eth");
+ dissector_add("wtap_encap", WTAP_ENCAP_ETHERNET, eth_handle);
+ dissector_add("ethertype", ETHERTYPE_ETHBRIDGE, eth_handle);
+ dissector_add("chdlctype", ETHERTYPE_ETHBRIDGE, eth_handle);
+ dissector_add("gre.proto", ETHERTYPE_ETHBRIDGE, eth_handle);
}