![Michael Mann](/assets/img/avatar_default.png)
This saves many dissectors the need to find the data dissector and store a handle to it. There were also some that were finding it, but not using it. For others this was the only reason for their handoff function, so it could be eliminated. Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b Reviewed-on: https://code.wireshark.org/review/14530 Petri-Dish: Michael Mann <mmann78@netscape.net> Reviewed-by: Michael Mann <mmann78@netscape.net>
427 lines
14 KiB
C
427 lines
14 KiB
C
/* packet-isl.c
|
|
* Routines for Cisco ISL Ethernet header disassembly
|
|
*
|
|
* Wireshark - Network traffic analyzer
|
|
* By Gerald Combs <gerald@wireshark.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <epan/packet.h>
|
|
#include <epan/exceptions.h>
|
|
#include <epan/show_exception.h>
|
|
|
|
#include "packet-isl.h"
|
|
#include "packet-eth.h"
|
|
#include "packet-tr.h"
|
|
|
|
void proto_register_isl(void);
|
|
void proto_reg_handoff_isl(void);
|
|
|
|
/*
|
|
* See
|
|
*
|
|
* http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094665.shtml
|
|
*
|
|
* and
|
|
*
|
|
* http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
|
|
*
|
|
* for information on ISL.
|
|
*/
|
|
static int proto_isl = -1;
|
|
static int hf_isl_dst = -1;
|
|
static int hf_isl_type = -1;
|
|
static int hf_isl_user_eth = -1;
|
|
static int hf_isl_user = -1;
|
|
static int hf_isl_src = -1;
|
|
static int hf_isl_addr = -1;
|
|
static int hf_isl_len = -1;
|
|
static int hf_isl_hsa = -1;
|
|
static int hf_isl_dsap = -1;
|
|
static int hf_isl_ssap = -1;
|
|
static int hf_isl_control = -1;
|
|
static int hf_isl_vlan_id = -1;
|
|
static int hf_isl_bpdu = -1;
|
|
static int hf_isl_index = -1;
|
|
static int hf_isl_reserved = -1;
|
|
/* static int hf_isl_crc = -1; */
|
|
static int hf_isl_src_vlan_id = -1;
|
|
static int hf_isl_explorer = -1;
|
|
static int hf_isl_dst_route_descriptor = -1;
|
|
static int hf_isl_src_route_descriptor = -1;
|
|
static int hf_isl_fcs_not_incl = -1;
|
|
static int hf_isl_esize = -1;
|
|
static int hf_isl_trailer = -1;
|
|
|
|
static gint ett_isl = -1;
|
|
static gint ett_isl_dst = -1;
|
|
|
|
#define ISL_HEADER_SIZE 26
|
|
|
|
#define TYPE_ETHER 0x0
|
|
#define TYPE_TR 0x1
|
|
#define TYPE_FDDI 0x2
|
|
#define TYPE_ATM 0x3
|
|
|
|
#define USER_PRIORITY_NORMAL 0x0
|
|
#define USER_PRIORITY_1 0x1
|
|
#define USER_PRIORITY_2 0x2
|
|
#define USER_PRIORITY_HIGHEST 0x3
|
|
|
|
static dissector_handle_t eth_withfcs_handle;
|
|
static dissector_handle_t tr_handle;
|
|
|
|
gboolean
|
|
capture_isl(const guchar *pd, int offset, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_)
|
|
{
|
|
guint8 type;
|
|
|
|
if (!BYTES_ARE_IN_FRAME(offset, len, ISL_HEADER_SIZE))
|
|
return FALSE;
|
|
|
|
type = (pd[offset+5] >> 4)&0x0F;
|
|
|
|
switch (type) {
|
|
|
|
case TYPE_ETHER:
|
|
offset += 14+12; /* skip the header */
|
|
return capture_eth(pd, offset, len, cpinfo, pseudo_header);
|
|
|
|
case TYPE_TR:
|
|
offset += 14+17; /* skip the header */
|
|
return capture_tr(pd, offset, len, cpinfo, pseudo_header);
|
|
break;
|
|
}
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
static const value_string type_vals[] = {
|
|
{TYPE_ETHER, "Ethernet"},
|
|
{TYPE_TR, "Token-Ring"},
|
|
{TYPE_FDDI, "FDDI"},
|
|
{TYPE_ATM, "ATM"},
|
|
{0, NULL}
|
|
};
|
|
|
|
static const value_string user_vals[] = {
|
|
{USER_PRIORITY_NORMAL, "Normal Priority"},
|
|
{USER_PRIORITY_1, "Priority 1"},
|
|
{USER_PRIORITY_2, "Priority 2"},
|
|
{USER_PRIORITY_HIGHEST, "Highest Priority"},
|
|
{0, NULL}
|
|
};
|
|
|
|
static const true_false_string explorer_tfs = {
|
|
"Explorer frame",
|
|
"Data frame"
|
|
};
|
|
|
|
void
|
|
dissect_isl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int fcs_len)
|
|
{
|
|
proto_tree *volatile fh_tree = NULL;
|
|
proto_tree *dst_tree;
|
|
proto_item *ti, *hidden_item;
|
|
volatile guint8 type;
|
|
volatile guint16 length;
|
|
gint captured_length;
|
|
tvbuff_t *volatile payload_tvb = NULL;
|
|
tvbuff_t *volatile next_tvb;
|
|
tvbuff_t *volatile trailer_tvb = NULL;
|
|
const char *saved_proto;
|
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ISL");
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
type = (tvb_get_guint8(tvb, 5) >> 4)&0x0F;
|
|
|
|
if (tree) {
|
|
ti = proto_tree_add_protocol_format(tree, proto_isl, tvb, 0, ISL_HEADER_SIZE,
|
|
"ISL");
|
|
fh_tree = proto_item_add_subtree(ti, ett_isl);
|
|
|
|
ti = proto_tree_add_item(fh_tree, hf_isl_dst, tvb, 0, 6, ENC_NA);
|
|
hidden_item = proto_tree_add_item(fh_tree, hf_isl_addr, tvb, 0, 6, ENC_NA);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
dst_tree = proto_item_add_subtree(ti, ett_isl_dst);
|
|
proto_tree_add_item(dst_tree, hf_isl_type, tvb, 5, 1, ENC_BIG_ENDIAN);
|
|
|
|
switch (type) {
|
|
|
|
case TYPE_ETHER:
|
|
proto_tree_add_item(dst_tree, hf_isl_user_eth, tvb, 5, 1, ENC_BIG_ENDIAN);
|
|
break;
|
|
|
|
default:
|
|
/* XXX - the spec appears to indicate that the "User" field is
|
|
used for TYPE_TR to distinguish between types of packets. */
|
|
proto_tree_add_item(dst_tree, hf_isl_user, tvb, 5, 1, ENC_BIG_ENDIAN);
|
|
break;
|
|
}
|
|
proto_tree_add_item(fh_tree, hf_isl_src, tvb, 6, 6, ENC_NA);
|
|
hidden_item = proto_tree_add_item(fh_tree, hf_isl_addr, tvb, 6, 6, ENC_NA);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
}
|
|
length = tvb_get_ntohs(tvb, 12);
|
|
if (tree)
|
|
proto_tree_add_uint(fh_tree, hf_isl_len, tvb, 12, 2, length);
|
|
|
|
if (length != 0) {
|
|
/* The length field was set; it's like an 802.3 length field, so
|
|
treat it similarly, by constructing a tvbuff containing only
|
|
the data specified by the length field. */
|
|
|
|
TRY {
|
|
payload_tvb = tvb_new_subset_length(tvb, 14, length);
|
|
trailer_tvb = tvb_new_subset_remaining(tvb, 14 + length);
|
|
}
|
|
CATCH_BOUNDS_ERRORS {
|
|
/* Either:
|
|
|
|
the packet doesn't have "length" bytes worth of
|
|
captured data left in it - or it may not even have
|
|
"length" bytes worth of data in it, period -
|
|
so the "tvb_new_subset()" creating "payload_tvb"
|
|
threw an exception
|
|
|
|
or
|
|
|
|
the packet has exactly "length" bytes worth of
|
|
captured data left in it, so the "tvb_new_subset_remaining()"
|
|
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. */
|
|
payload_tvb = tvb_new_subset(tvb, 14, -1, length);
|
|
trailer_tvb = NULL;
|
|
}
|
|
ENDTRY;
|
|
} else {
|
|
/* The length field is 0; make it the length remaining in the packet
|
|
after the first 14 bytes. */
|
|
length = tvb_reported_length_remaining(tvb, 14);
|
|
payload_tvb = tvb_new_subset_remaining(tvb, 14);
|
|
trailer_tvb = NULL;
|
|
}
|
|
|
|
if (tree) {
|
|
/* This part looks sort of like a SNAP-encapsulated LLC header... */
|
|
proto_tree_add_item(fh_tree, hf_isl_dsap, payload_tvb, 0, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_ssap, payload_tvb, 1, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_control, payload_tvb, 2, 1, ENC_BIG_ENDIAN);
|
|
|
|
/* ...but this is the manufacturer's ID portion of the source address
|
|
field (which is, admittedly, an OUI). */
|
|
proto_tree_add_item(fh_tree, hf_isl_hsa, payload_tvb, 3, 3, ENC_BIG_ENDIAN);
|
|
}
|
|
col_add_fstr(pinfo->cinfo, COL_INFO, "VLAN ID: %u",
|
|
tvb_get_ntohs(tvb, 20) >> 1);
|
|
if (tree) {
|
|
proto_tree_add_item(fh_tree, hf_isl_vlan_id, payload_tvb, 6, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_bpdu, payload_tvb, 6, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_index, payload_tvb, 8, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_reserved, payload_tvb, 10, 2, ENC_BIG_ENDIAN);
|
|
}
|
|
|
|
switch (type) {
|
|
|
|
case TYPE_ETHER:
|
|
/* The length of the encapsulated frame is the length from the
|
|
header, minus 12 bytes for the part of the ISL header that
|
|
follows the length. */
|
|
if (length >= 12) {
|
|
/* Well, we at least had that much data in the frame. Try
|
|
dissecting what's left as an Ethernet frame. */
|
|
length -= 12;
|
|
|
|
/* Trim the captured length. */
|
|
captured_length = tvb_captured_length_remaining(payload_tvb, 12);
|
|
|
|
/* Make sure it's not bigger than the actual length. */
|
|
if (captured_length > length)
|
|
captured_length = length;
|
|
|
|
next_tvb = tvb_new_subset(payload_tvb, 12, captured_length, length);
|
|
|
|
/* Dissect the payload as an Ethernet frame.
|
|
|
|
Catch BoundsError and ReportedBoundsError, so that if the
|
|
reported length of "next_tvb" was reduced by some dissector
|
|
before an exception was thrown, we can still put in an item
|
|
for the trailer. */
|
|
saved_proto = pinfo->current_proto;
|
|
TRY {
|
|
/* Frames encapsulated in ISL include an FCS. */
|
|
call_dissector(eth_withfcs_handle, next_tvb, pinfo, tree);
|
|
}
|
|
CATCH_NONFATAL_ERRORS {
|
|
/* Somebody threw an exception that indicates a problem with
|
|
the payload, but doesn't indicate anything that would
|
|
keep us from dissecting the trailer.
|
|
|
|
Show the exception, and then drive on to show the trailer,
|
|
restoring the protocol value that was in effect before we
|
|
called the subdissector.
|
|
*/
|
|
|
|
show_exception(next_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);
|
|
pinfo->current_proto = saved_proto;
|
|
}
|
|
ENDTRY;
|
|
|
|
/* Now add the Ethernet trailer and FCS.
|
|
XXX - do this only if we're encapsulated in Ethernet? */
|
|
add_ethernet_trailer(pinfo, tree, fh_tree, hf_isl_trailer, tvb, trailer_tvb, fcs_len);
|
|
}
|
|
break;
|
|
|
|
case TYPE_TR:
|
|
if (tree) {
|
|
proto_tree_add_item(fh_tree, hf_isl_src_vlan_id, payload_tvb, 10, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_explorer, payload_tvb, 10, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_dst_route_descriptor, payload_tvb, 12, 2, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_src_route_descriptor, payload_tvb, 14, 2, ENC_BIG_ENDIAN);
|
|
/* This doesn't appear to be present in at least one capture I've seen. */
|
|
proto_tree_add_item(fh_tree, hf_isl_fcs_not_incl, payload_tvb, 16, 1, ENC_BIG_ENDIAN);
|
|
proto_tree_add_item(fh_tree, hf_isl_esize, payload_tvb, 16, 1, ENC_BIG_ENDIAN);
|
|
}
|
|
next_tvb = tvb_new_subset_remaining(payload_tvb, 17);
|
|
call_dissector(tr_handle, next_tvb, pinfo, tree);
|
|
break;
|
|
|
|
default:
|
|
next_tvb = tvb_new_subset_remaining(payload_tvb, 12);
|
|
call_data_dissector(next_tvb, pinfo, tree);
|
|
break;
|
|
}
|
|
}
|
|
|
|
void
|
|
proto_register_isl(void)
|
|
{
|
|
static hf_register_info hf[] = {
|
|
{ &hf_isl_dst,
|
|
{ "Destination", "isl.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Destination Address", HFILL }},
|
|
{ &hf_isl_type,
|
|
{ "Type", "isl.type", FT_UINT8, BASE_DEC,
|
|
VALS(type_vals), 0xF0, NULL, HFILL }},
|
|
{ &hf_isl_user_eth,
|
|
{ "User", "isl.user_eth", FT_UINT8, BASE_DEC,
|
|
VALS(user_vals), 0x03, "Priority while passing through switch", HFILL }},
|
|
{ &hf_isl_user,
|
|
{ "User", "isl.user", FT_UINT8, BASE_HEX, NULL, 0x0F,
|
|
"User-defined bits", HFILL }},
|
|
{ &hf_isl_src,
|
|
{ "Source", "isl.src", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Source Hardware Address", HFILL }},
|
|
{ &hf_isl_addr,
|
|
{ "Source or Destination Address", "isl.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Source or Destination Hardware Address", HFILL }},
|
|
{ &hf_isl_len,
|
|
{ "Length", "isl.len", FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
{ &hf_isl_hsa,
|
|
{ "HSA", "isl.hsa", FT_UINT24, BASE_HEX, NULL, 0x0,
|
|
"High bits of source address", HFILL }},
|
|
{ &hf_isl_dsap,
|
|
{ "DSAP", "isl.dsap", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
{ &hf_isl_ssap,
|
|
{ "SSAP", "isl.ssap", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
{ &hf_isl_control,
|
|
{ "Control", "isl.control", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
{ &hf_isl_vlan_id,
|
|
{ "VLAN ID", "isl.vlan_id", FT_UINT16, BASE_DEC, NULL,
|
|
0xFFFE, "Virtual LAN ID (Color)", HFILL }},
|
|
{ &hf_isl_bpdu,
|
|
{ "BPDU/CDP/VTP", "isl.bpdu", FT_BOOLEAN, 16,
|
|
TFS(&tfs_yes_no), 0x0001, "BPDU/CDP/VTP indicator", HFILL }},
|
|
{ &hf_isl_index,
|
|
{ "Index", "isl.index", FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Port index of packet source", HFILL }},
|
|
{ &hf_isl_reserved,
|
|
{ "Reserved", "isl.reserved", FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
"ISL Reserved", HFILL }},
|
|
#if 0
|
|
{ &hf_isl_crc,
|
|
{ "CRC", "isl.crc", FT_UINT32, BASE_HEX, NULL, 0x0,
|
|
"CRC field of encapsulated frame", HFILL }},
|
|
#endif
|
|
{ &hf_isl_src_vlan_id,
|
|
{ "Source VLAN ID", "isl.src_vlan_id", FT_UINT16, BASE_DEC, NULL,
|
|
0xFFFE, "Source Virtual LAN ID (Color)", HFILL }},
|
|
{ &hf_isl_explorer,
|
|
{ "Explorer", "isl.explorer", FT_BOOLEAN, 16,
|
|
TFS(&explorer_tfs), 0x0001, NULL, HFILL }},
|
|
{ &hf_isl_dst_route_descriptor,
|
|
{ "Destination route descriptor", "isl.dst_route_desc",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
"Route descriptor to be used for forwarding", HFILL }},
|
|
{ &hf_isl_src_route_descriptor,
|
|
{ "Source-route descriptor", "isl.src_route_desc",
|
|
FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
"Route descriptor to be used for source learning", HFILL }},
|
|
{ &hf_isl_fcs_not_incl,
|
|
{ "FCS Not Included", "isl.fcs_not_incl", FT_BOOLEAN, 9,
|
|
NULL, 0x40, NULL, HFILL }},
|
|
{ &hf_isl_esize,
|
|
{ "Esize", "isl.esize", FT_UINT8, BASE_DEC, NULL,
|
|
0x3F, "Frame size for frames less than 64 bytes", HFILL }},
|
|
{ &hf_isl_trailer,
|
|
{ "Trailer", "isl.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
"Ethernet Trailer or Checksum", HFILL }},
|
|
};
|
|
static gint *ett[] = {
|
|
&ett_isl,
|
|
&ett_isl_dst,
|
|
};
|
|
|
|
proto_isl = proto_register_protocol("Cisco ISL", "ISL", "isl");
|
|
proto_register_field_array(proto_isl, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_isl(void)
|
|
{
|
|
/*
|
|
* Get handles for the Ethernet and Token Ring dissectors.
|
|
*/
|
|
eth_withfcs_handle = find_dissector_add_dependency("eth_withfcs", proto_isl);
|
|
tr_handle = find_dissector_add_dependency("tr", proto_isl);
|
|
}
|
|
|
|
/*
|
|
* Editor modelines - http://www.wireshark.org/tools/modelines.html
|
|
*
|
|
* Local Variables:
|
|
* c-basic-offset: 2
|
|
* tab-width: 8
|
|
* indent-tabs-mode: nil
|
|
* End:
|
|
*
|
|
* ex: set shiftwidth=2 tabstop=8 expandtab:
|
|
* :indentSize=2:tabSize=8:noTabs=true:
|
|
*/
|