*
* $Id$
*
- * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@ethereal.com>
+ * 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
#include "packet-isl.h"
#include "packet-eth.h"
#include "packet-tr.h"
-#include "etypes.h"
+#include "packet-frame.h"
+#include <epan/etypes.h>
/*
* See
*
* http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
*
+ * and
+ *
+ * http://www.cisco.com/en/US/tech/tk389/tk390/technologies_tech_note09186a0080094665.shtml
+ *
* for information on ISL.
*/
static int proto_isl = -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;
#define TYPE_FDDI 0x2
#define TYPE_ATM 0x3
-static dissector_handle_t eth_handle;
+static dissector_handle_t eth_withfcs_handle;
static dissector_handle_t tr_handle;
static dissector_handle_t data_handle;
};
static const value_string ether_user_vals[] = {
- {0x0, "Normal priority"},
- {0x1, "Priority 1"},
- {0x2, "Priority 2"},
- {0x3, "Highest priority"},
+ /* User values are defined by IEEE 802.1D-2004, annex G */
+ {0x0, "Best effort (default priority)"},
+ {0x1, "Background"},
+ {0x2, "[spare priority]"},
+ {0x3, "Excellent effort"},
+ {0x4, "Controlled load"},
+ {0x5, "\"Video\", < 100ms latency and jitter"},
+ {0x6, "\"Voice\", < 10ms latency and jitter"},
+ {0x7, "Network control"},
{0, NULL}
};
"Data frame"
};
-static void
-dissect_isl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+void
+dissect_isl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int fcs_len)
{
- proto_tree *fh_tree = NULL;
- proto_item *ti;
- guint8 type;
- guint16 length;
- gint crc_offset;
+ proto_tree *volatile fh_tree = NULL;
+ proto_item *ti, *hidden_item;
+ volatile guint8 type;
+ volatile guint16 length;
gint captured_length;
- tvbuff_t *next_tvb;
+ tvbuff_t *volatile payload_tvb = NULL;
+ tvbuff_t *volatile next_tvb;
+ tvbuff_t *volatile trailer_tvb = NULL;
+ const char *saved_proto;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ISL");
ti = proto_tree_add_protocol_format(tree, proto_isl, tvb, 0, ISL_HEADER_SIZE,
"ISL");
fh_tree = proto_item_add_subtree(ti, ett_isl);
- proto_tree_add_item(fh_tree, hf_isl_dst, tvb, 0, 6, FALSE);
- proto_tree_add_item_hidden(fh_tree, hf_isl_addr, tvb, 0, 6, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_dst, tvb, 0, 5, FALSE);
+ hidden_item = proto_tree_add_item(fh_tree, hf_isl_addr, tvb, 0, 6, FALSE);
+ PROTO_ITEM_SET_HIDDEN(hidden_item);
proto_tree_add_item(fh_tree, hf_isl_type, tvb, 5, 1, FALSE);
switch (type) {
break;
}
proto_tree_add_item(fh_tree, hf_isl_src, tvb, 6, 6, FALSE);
- proto_tree_add_item_hidden(fh_tree, hf_isl_addr, tvb, 6, 6, FALSE);
+ hidden_item = proto_tree_add_item(fh_tree, hf_isl_addr, tvb, 6, 6, FALSE);
+ PROTO_ITEM_SET_HIDDEN(hidden_item);
}
length = tvb_get_ntohs(tvb, 12);
- if (tree) {
+ 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(tvb, 14, length, length);
+ trailer_tvb = tvb_new_subset(tvb, 14 + length, -1, -1);
+ }
+ CATCH2(BoundsError, ReportedBoundsError) {
+ /* 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()"
+ 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(tvb, 14, -1, -1);
+ trailer_tvb = NULL;
+ }
+
+ if (tree) {
+ tvb_ensure_bytes_exist(payload_tvb, 0, 6);
/* This part looks sort of like a SNAP-encapsulated LLC header... */
- proto_tree_add_text(fh_tree, tvb, 14, 1, "DSAP: 0x%X", tvb_get_guint8(tvb, 14));
- proto_tree_add_text(fh_tree, tvb, 15, 1, "SSAP: 0x%X", tvb_get_guint8(tvb, 15));
- proto_tree_add_text(fh_tree, tvb, 16, 1, "Control: 0x%X", tvb_get_guint8(tvb, 16));
+ proto_tree_add_text(fh_tree, payload_tvb, 0, 1, "DSAP: 0x%X", tvb_get_guint8(tvb, 14));
+ proto_tree_add_text(fh_tree, payload_tvb, 1, 1, "SSAP: 0x%X", tvb_get_guint8(tvb, 15));
+ proto_tree_add_text(fh_tree, payload_tvb, 2, 1, "Control: 0x%X", tvb_get_guint8(tvb, 16));
/* ...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, tvb, 17, 3, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_hsa, payload_tvb, 3, 3, FALSE);
}
if (check_col(pinfo->cinfo, COL_INFO))
col_add_fstr(pinfo->cinfo, COL_INFO, "VLAN ID: 0x%04X",
tvb_get_ntohs(tvb, 20) >> 1);
if (tree) {
- proto_tree_add_item(fh_tree, hf_isl_vlan_id, tvb, 20, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_bpdu, tvb, 20, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_index, tvb, 22, 2, FALSE);
-
- /* Now for the encapsulated frame's CRC, which is at the *end* of the
- packet; "length" is the length of the frame, not including the
- first 14 bytes of the frame, but including the encapsulated
- frame's CRC, which is 4 bytes long, so the offset of the
- encapsulated CRC is "length + 14 - 4".
-
- We check for the CRC and display it only if we have that data,
- rather than throwing an exception before we've dissected any
- of the rest of the frame. */
- crc_offset = length + 14 - 4;
- if (tvb_bytes_exist(tvb, crc_offset, 4))
- proto_tree_add_item(fh_tree, hf_isl_crc, tvb, crc_offset, 4, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_vlan_id, payload_tvb, 6, 2, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_bpdu, payload_tvb, 6, 2, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_index, payload_tvb, 8, 2, FALSE);
}
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 and 4 bytes for the encapsulated frame
- CRC. */
- if (length >= 12+4) {
+ 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+4;
+ length -= 12;
/* Trim the captured length. */
- captured_length = tvb_length_remaining(tvb, ISL_HEADER_SIZE);
- if (captured_length > 4) {
- /* Subtract the encapsulated frame CRC. */
- captured_length -= 4;
+ captured_length = tvb_length_remaining(payload_tvb, 12);
- /* Make sure it's not bigger than the actual length. */
- if (captured_length > length)
- captured_length = length;
+ /* Make sure it's not bigger than the actual length. */
+ if (captured_length > length)
+ captured_length = length;
- next_tvb = tvb_new_subset(tvb, ISL_HEADER_SIZE, captured_length, length);
+ next_tvb = tvb_new_subset(payload_tvb, 12, captured_length, length);
- call_dissector(eth_handle, next_tvb, pinfo, tree);
+ /* Dissect the payload as an Etherner 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(BoundsError) {
+ /* Somebody threw BoundsError, which means that dissecting the payload
+ found that the packet was cut off by a snapshot length before the
+ end of the payload. The trailer comes after the payload, so *all*
+ of the trailer is cut off - don't bother adding the trailer, just
+ rethrow the exception so it gets reported. */
+ RETHROW;
}
+ CATCH_ALL {
+ /* Well, somebody threw an exception other than BoundsError.
+ 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, 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, tvb, 24, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_explorer, tvb, 24, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_dst_route_descriptor, tvb, 26, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_src_route_descriptor, tvb, 28, 2, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_fcs_not_incl, tvb, 30, 1, FALSE);
- proto_tree_add_item(fh_tree, hf_isl_esize, tvb, 30, 1, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_src_vlan_id, payload_tvb, 10, 2, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_explorer, payload_tvb, 10, 2, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_dst_route_descriptor, payload_tvb, 12, 2, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_src_route_descriptor, payload_tvb, 14, 2, FALSE);
+ /* 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, FALSE);
+ proto_tree_add_item(fh_tree, hf_isl_esize, payload_tvb, 16, 1, FALSE);
}
- next_tvb = tvb_new_subset(tvb, 31, -1, -1);
+ next_tvb = tvb_new_subset(payload_tvb, 17, -1, -1);
call_dissector(tr_handle, next_tvb, pinfo, tree);
break;
default:
- next_tvb = tvb_new_subset(tvb, ISL_HEADER_SIZE, -1, -1);
- call_dissector(data_handle,next_tvb, pinfo, tree);
+ next_tvb = tvb_new_subset(payload_tvb, 12, -1, -1);
+ call_dissector(data_handle, next_tvb, pinfo, tree);
break;
}
}
{
static hf_register_info hf[] = {
{ &hf_isl_dst,
- { "Destination", "isl.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
+ { "Destination", "isl.dst", FT_BYTES, BASE_NONE, NULL, 0x0,
"Destination Address", HFILL }},
{ &hf_isl_type,
{ "Type", "isl.type", FT_UINT8, BASE_DEC,
- VALS(type_vals), 0xF0, "Type", HFILL }},
+ VALS(type_vals), 0xF0, NULL, HFILL }},
{ &hf_isl_user_eth,
{ "User", "isl.user_eth", FT_UINT8, BASE_DEC,
VALS(ether_user_vals), 0x0F, "Priority (for Ethernet)", HFILL }},
"Source or Destination Hardware Address", HFILL }},
{ &hf_isl_len,
{ "Length", "isl.len", FT_UINT16, BASE_DEC, NULL, 0x0,
- "", HFILL }},
+ NULL, HFILL }},
{ &hf_isl_hsa,
{ "HSA", "isl.hsa", FT_UINT24, BASE_HEX, NULL, 0x0,
"High bits of source address", HFILL }},
0xFFFE, "Source Virtual LAN ID", HFILL }},
{ &hf_isl_explorer,
{ "Explorer", "isl.explorer", FT_BOOLEAN, 16,
- TFS(&explorer_tfs), 0x0001, "Explorer", HFILL }},
+ TFS(&explorer_tfs), 0x0001, NULL, HFILL }},
{ &hf_isl_dst_route_descriptor,
{ "Destination route descriptor", "isl.dst_route_desc",
FT_UINT16, BASE_HEX, NULL, 0x0,
{ &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,
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));
-
- register_dissector("isl", dissect_isl, proto_isl);
}
void
/*
* Get handles for the Ethernet and Token Ring dissectors.
*/
- eth_handle = find_dissector("eth");
+ eth_withfcs_handle = find_dissector("eth_withfcs");
tr_handle = find_dissector("tr");
data_handle = find_dissector("data");
}
git.samba.org / obnox / wireshark / wip.git / blobdiff