/* packet-eth.c
* Routines for ethernet packet disassembly
*
- * $Id: packet-eth.c,v 1.26 2000/01/23 08:55:32 guy Exp $
+ * $Id: packet-eth.c,v 1.66 2001/06/29 09:42:45 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
#include "packet.h"
#include "etypes.h"
#include "resolv.h"
-
-extern const value_string etype_vals[];
+#include "packet-eth.h"
+#include "packet-ieee8023.h"
+#include "packet-ipx.h"
+#include "packet-isl.h"
+#include "packet-llc.h"
/* protocols and header fields */
static int proto_eth = -1;
static int hf_eth_src = -1;
static int hf_eth_len = -1;
static int hf_eth_type = -1;
+static int hf_eth_addr = -1;
+static int hf_eth_trailer = -1;
static gint ett_ieee8023 = -1;
static gint ett_ether2 = -1;
+static dissector_handle_t isl_handle;
+
#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 802.3 header
+ 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
ethhdr_type = ETHERNET_802_2;
}
+ /* 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 (pd[offset] == 0x01 && pd[offset+1] == 0x00 && pd[offset+2] == 0x0C
+ && pd[offset+3] == 0x00 && pd[offset+4] == 0x00) {
+ capture_isl(pd, offset, ld);
+ return;
+ }
+
/* Convert the LLC length from the 802.3 header to a total
- length, by adding in the Ethernet header size, and set
- the payload and captured-payload lengths to the minima
+ 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_HEADER_SIZE;
+ length += offset + ETH_HEADER_SIZE;
if (pi.len > length)
pi.len = length;
if (pi.captured_len > length)
}
}
-void
-dissect_eth(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
- guint16 etype, length;
- proto_tree *fh_tree = NULL;
- proto_item *ti;
- int ethhdr_type; /* the type of ethernet frame */
+static void
+dissect_eth(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+ int orig_captured_len;
+ proto_item *ti;
+ const guint8 *dst, *src;
+ const guint8 *pd;
- if (!BYTES_ARE_IN_FRAME(offset, ETH_HEADER_SIZE)) {
- dissect_data(pd, offset, fd, tree);
- return;
- }
+ guint16 etype;
+ volatile gboolean is_802_2;
+ int eth_offset;
+ volatile guint16 length;
+ proto_tree *volatile fh_tree = NULL;
- SET_ADDRESS(&pi.dl_src, AT_ETHER, 6, &pd[offset+6]);
- SET_ADDRESS(&pi.src, AT_ETHER, 6, &pd[offset+6]);
- SET_ADDRESS(&pi.dl_dst, AT_ETHER, 6, &pd[offset+0]);
- SET_ADDRESS(&pi.dst, AT_ETHER, 6, &pd[offset+0]);
+ tvb_compat(tvb, &pd, (int*)ð_offset);
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "Ethernet");
+ orig_captured_len = pinfo->captured_len;
- etype = pntohs(&pd[offset+12]);
+ if (check_col(pinfo->fd, COL_PROTOCOL))
+ col_set_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;
+ /* 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);
+ return;
+ }
+
/* 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[offset+14] == 0xff && pd[offset+15] == 0xff) {
- ethhdr_type = ETHERNET_802_3;
+ is_802_2 = TRUE;
+ TRY {
+ if (tvb_get_ntohs(tvb, 14) == 0xffff) {
+ is_802_2 = FALSE;
+ }
}
- else {
- ethhdr_type = ETHERNET_802_2;
+ CATCH2(BoundsError, ReportedBoundsError) {
+ ; /* do nothing */
+
}
+ ENDTRY;
- if (check_col(fd, COL_INFO)) {
- col_add_fstr(fd, COL_INFO, "IEEE 802.3 %s",
- (ethhdr_type == ETHERNET_802_3 ? "Raw " : ""));
+ if (check_col(pinfo->fd, COL_INFO)) {
+ col_add_fstr(pinfo->fd, 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_item_format(tree, proto_eth, offset, ETH_HEADER_SIZE,
- NULL, "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_item(fh_tree, hf_eth_dst, offset+0, 6, &pd[offset+0]);
- proto_tree_add_item(fh_tree, hf_eth_src, offset+6, 6, &pd[offset+6]);
- proto_tree_add_item(fh_tree, hf_eth_len, offset+12, 2, length);
+/* 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);
}
/* Convert the LLC length from the 802.3 header to a total
- length, by 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_HEADER_SIZE;
- if (pi.len > length)
- pi.len = length;
- if (pi.captured_len > length)
- pi.captured_len = length;
+ 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.
+
+ XXX - when all dissectors are tvbuffified we shouldn't have to
+ do this any more. */
+ length += eth_offset + ETH_HEADER_SIZE;
+ if (pinfo->len > length)
+ pinfo->len = length;
+ if (pinfo->captured_len > length)
+ pinfo->captured_len = length;
+
+ dissect_802_3(etype, is_802_2, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree,
+ hf_eth_len, hf_eth_trailer);
} else {
- ethhdr_type = ETHERNET_II;
- if (check_col(fd, COL_INFO))
- col_add_str(fd, COL_INFO, "Ethernet II");
+ if (check_col(pinfo->fd, COL_INFO))
+ col_set_str(pinfo->fd, COL_INFO, "Ethernet II");
if (tree) {
+ ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+ "Ethernet II");
- ti = proto_tree_add_item_format(tree, proto_eth, offset, ETH_HEADER_SIZE,
- NULL, "Ethernet II");
-
- fh_tree = proto_item_add_subtree(ti, ett_ether2);
+ fh_tree = proto_item_add_subtree(ti, ett_ether2);
- proto_tree_add_item(fh_tree, hf_eth_dst, offset+0, 6, &pd[offset+0]);
- proto_tree_add_item(fh_tree, hf_eth_src, offset+6, 6, &pd[offset+6]);
+ 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);
+/* 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);
}
- }
- offset += ETH_HEADER_SIZE;
- switch (ethhdr_type) {
- case ETHERNET_802_3:
- dissect_ipx(pd, offset, fd, tree);
- break;
- case ETHERNET_802_2:
- dissect_llc(pd, offset, fd, tree);
- break;
- case ETHERNET_II:
- ethertype(etype, offset, pd, fd, tree, fh_tree, hf_eth_type);
- break;
+ ethertype(etype, tvb, ETH_HEADER_SIZE, pinfo, tree, fh_tree, hf_eth_type,
+ hf_eth_trailer);
}
}
{ &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", HFILL }},
+
+ { &hf_eth_trailer,
+ { "Trailer", "eth.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
+ "Ethernet Trailer or Checksum", HFILL }},
+
};
static gint *ett[] = {
&ett_ieee8023,
&ett_ether2,
};
- 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_dissector("eth", dissect_eth, proto_eth);
+}
+
+void
+proto_reg_handoff_eth(void)
+{
+ /*
+ * Get a handle for the ISL dissector.
+ */
+ isl_handle = find_dissector("isl");
+
+ dissector_add("wtap_encap", WTAP_ENCAP_ETHERNET, dissect_eth,
+ proto_eth);
+ dissector_add("ethertype", ETHERTYPE_ETHBRIDGE, dissect_eth,
+ proto_eth);
+ dissector_add("chdlctype", ETHERTYPE_ETHBRIDGE, dissect_eth,
+ proto_eth);
+ dissector_add("gre.proto", ETHERTYPE_ETHBRIDGE, dissect_eth,
+ proto_eth);
}