![Guy Harris](/assets/img/avatar_default.png)
keys to have _uint in their names, to match the routines that handle dissector tables with string keys. (Using _port can confuse people into thinking they're intended solely for use with TCP/UDP/etc. ports when, in fact, they work better for things such as Ethernet types, where the binding of particular values to particular protocols are a lot stronger.) svn path=/trunk/; revision=35224
757 lines
22 KiB
C
757 lines
22 KiB
C
/* packet-tr.c
|
|
* Routines for Token-Ring packet disassembly
|
|
* Gilbert Ramirez <gram@alumni.rice.edu>
|
|
*
|
|
* $Id$
|
|
*
|
|
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include <string.h>
|
|
#include <glib.h>
|
|
#include <epan/packet.h>
|
|
#include "packet-tr.h"
|
|
#include "packet-llc.h"
|
|
#include <epan/prefs.h>
|
|
#include <epan/tap.h>
|
|
#include <epan/emem.h>
|
|
|
|
static int proto_tr = -1;
|
|
static int hf_tr_dst = -1;
|
|
static int hf_tr_src = -1;
|
|
static int hf_tr_addr = -1;
|
|
static int hf_tr_sr = -1;
|
|
static int hf_tr_ac = -1;
|
|
static int hf_tr_priority = -1;
|
|
static int hf_tr_frame = -1;
|
|
static int hf_tr_monitor_cnt = -1;
|
|
static int hf_tr_priority_reservation = -1;
|
|
static int hf_tr_fc = -1;
|
|
static int hf_tr_fc_type = -1;
|
|
static int hf_tr_fc_pcf = -1;
|
|
static int hf_tr_rif_bytes = -1;
|
|
static int hf_tr_broadcast = -1;
|
|
static int hf_tr_max_frame_size = -1;
|
|
static int hf_tr_direction = -1;
|
|
static int hf_tr_rif = -1;
|
|
static int hf_tr_rif_ring = -1;
|
|
static int hf_tr_rif_bridge = -1;
|
|
|
|
static gint ett_token_ring = -1;
|
|
static gint ett_token_ring_ac = -1;
|
|
static gint ett_token_ring_fc = -1;
|
|
|
|
static int tr_tap = -1;
|
|
|
|
/*
|
|
* Check for and attempt to fix Linux link-layer header mangling.
|
|
*/
|
|
static gboolean fix_linux_botches = FALSE;
|
|
|
|
#define TR_MIN_HEADER_LEN 14
|
|
#define TR_MAX_HEADER_LEN 32
|
|
|
|
static const true_false_string ac_truth = { "Frame", "Token" };
|
|
|
|
static const value_string pcf_vals[] = {
|
|
{ 0, "Normal buffer" },
|
|
{ 1, "Express buffer" },
|
|
{ 2, "Purge" },
|
|
{ 3, "Claim Token" },
|
|
{ 4, "Beacon" },
|
|
{ 5, "Active Monitor Present" },
|
|
{ 6, "Standby Monitor Present" },
|
|
{ 0, NULL },
|
|
};
|
|
|
|
static const value_string frame_vals[] = {
|
|
{ 0, "MAC" },
|
|
{ 1, "LLC" },
|
|
{ 2, "Reserved" },
|
|
{ 0, NULL },
|
|
};
|
|
|
|
static const value_string broadcast_vals[] = {
|
|
{ 0 << 5, "Non-broadcast" },
|
|
{ 1 << 5, "Non-broadcast" },
|
|
{ 2 << 5, "Non-broadcast" },
|
|
{ 3 << 5, "Non-broadcast" },
|
|
{ 4 << 5, "All-routes broadcast" },
|
|
{ 5 << 5, "All-routes broadcast" },
|
|
{ 6 << 5, "Single-route broadcast" },
|
|
{ 7 << 5, "Single-route broadcast" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
static const value_string max_frame_size_vals[] = {
|
|
{ 0 << 4, "516" },
|
|
{ 1 << 4, "1500" },
|
|
{ 2 << 4, "2052" },
|
|
{ 3 << 4, "4472" },
|
|
{ 4 << 4, "8144" },
|
|
{ 5 << 4, "11407" },
|
|
{ 6 << 4, "17800" },
|
|
{ 7 << 4, "65535" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
static const value_string direction_vals[] = {
|
|
{ 0, "From originating station (-->)" },
|
|
{ 128, "To originating station (<--)" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
static dissector_handle_t trmac_handle;
|
|
static dissector_handle_t llc_handle;
|
|
static dissector_handle_t data_handle;
|
|
|
|
/*
|
|
* DODGY LINUX HACK DODGY LINUX HACK
|
|
* Linux 2.0.x always passes frames to the Token Ring driver for transmission with
|
|
* 18 bytes padding for source routing information. Some drivers copy the first
|
|
* (18 - srlen) bytes up the frame (18 - srlen) bytes thus removing the padding.
|
|
* Other drivers just make a copy of the entire frame and then hack about with it
|
|
* so the frame the sniffer gets is fine (just has extra sr routing).
|
|
* In the first instance (driver hacking frame in situ) the sniffer gets a garbled
|
|
* frame.
|
|
* This function trys to detect this and returns the offset of where
|
|
* the frame really starts.
|
|
* This only detects frames that we have sent ourselves so if we are packet sniffing
|
|
* on the machine we are watching this is useful.
|
|
* Compare offset 0 with offset x+1 for a length of x bytes for all value of x = 1 to 18
|
|
* if match then Linux driver has done in situ source route compression of the crappy
|
|
* Linux 2.0.x frame so the beginning of the real frame is x bytes in.
|
|
* (And this real frame x bytes in looks like a proper TR frame that goes on the wire
|
|
* with none of the Linux idiosyncrasies).
|
|
*
|
|
* XXX - there should perhaps be a preference setting to turn this off,
|
|
* as sometimes it can, and does, get a false hit.
|
|
*/
|
|
static
|
|
int check_for_old_linux_tvb(tvbuff_t *tvb)
|
|
{
|
|
const guint8 *data;
|
|
int x, bytes;
|
|
|
|
/* Restrict our looping to the boundaries of the frame */
|
|
bytes = tvb_length(tvb);
|
|
if (bytes > 19) {
|
|
bytes = 19;
|
|
}
|
|
|
|
data = tvb_get_ptr(tvb, 0, bytes);
|
|
|
|
for(x = 1; x <= bytes-1 ;x++)
|
|
{
|
|
if (memcmp(&data[0], &data[x], x) == 0)
|
|
{
|
|
return x;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static
|
|
int check_for_old_linux(const guchar * pd)
|
|
{
|
|
int x;
|
|
for(x=1;x<=18;x++)
|
|
{
|
|
if (memcmp(&pd[0],&pd[x],x) == 0)
|
|
{
|
|
return x;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void
|
|
add_ring_bridge_pairs(int rcf_len, tvbuff_t*, proto_tree *tree);
|
|
|
|
void
|
|
capture_tr(const guchar *pd, int offset, int len, packet_counts *ld) {
|
|
|
|
int source_routed = 0;
|
|
int frame_type;
|
|
int x;
|
|
guint8 trn_rif_bytes;
|
|
guint8 actual_rif_bytes;
|
|
guint16 first2_sr;
|
|
|
|
/* The trn_hdr struct, as separate variables */
|
|
guint8 trn_fc; /* field control field */
|
|
const guint8 *trn_shost; /* source host */
|
|
|
|
if (!BYTES_ARE_IN_FRAME(offset, len, TR_MIN_HEADER_LEN)) {
|
|
ld->other++;
|
|
return;
|
|
}
|
|
|
|
if ((x = check_for_old_linux(pd)))
|
|
{
|
|
/* Actually packet starts x bytes into what we have got but with all
|
|
source routing compressed
|
|
*/
|
|
/* pd = &pd[x]; */ offset+=x;
|
|
}
|
|
|
|
/* get the data */
|
|
trn_fc = pd[offset + 1];
|
|
trn_shost = &pd[offset + 8];
|
|
|
|
frame_type = (trn_fc & 192) >> 6;
|
|
|
|
/* if the high bit on the first byte of src hwaddr is 1, then
|
|
this packet is source-routed */
|
|
source_routed = trn_shost[0] & 128;
|
|
|
|
trn_rif_bytes = pd[offset + 14] & 31;
|
|
|
|
if (fix_linux_botches) {
|
|
/* the Linux 2.0 TR code strips source-route bits in
|
|
* order to test for SR. This can be removed from most
|
|
* packets with oltr, but not all. So, I try to figure out
|
|
* which packets should have been SR here. I'll check to
|
|
* see if there's a SNAP or IPX field right after
|
|
* my RIF fields.
|
|
*
|
|
* The Linux 2.4.18 code, at least appears to do the
|
|
* same thing, from a capture I got from somebody running
|
|
* 2.4.18 (RH 7.1, so perhaps this is a Red Hat
|
|
* "improvement").
|
|
*/
|
|
if (!source_routed && trn_rif_bytes > 0) {
|
|
if (pd[offset + 0x0e] != pd[offset + 0x0f]) {
|
|
first2_sr = pntohs(&pd[offset + 0xe0 + trn_rif_bytes]);
|
|
if (
|
|
(first2_sr == 0xaaaa &&
|
|
pd[offset + 0x10 + trn_rif_bytes] == 0x03) ||
|
|
|
|
first2_sr == 0xe0e0 ||
|
|
first2_sr == 0xe0aa ) {
|
|
|
|
source_routed = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (source_routed) {
|
|
actual_rif_bytes = trn_rif_bytes;
|
|
}
|
|
else {
|
|
trn_rif_bytes = 0;
|
|
actual_rif_bytes = 0;
|
|
}
|
|
|
|
if (fix_linux_botches) {
|
|
/* this is a silly hack for Linux 2.0.x. Read the comment
|
|
* below about LLC headers. If we're sniffing our own NIC,
|
|
* we get a full RIF, sometimes with garbage
|
|
*/
|
|
if ((source_routed && trn_rif_bytes == 2 && frame_type == 1) ||
|
|
(!source_routed && frame_type == 1)) {
|
|
/* look for SNAP or IPX only */
|
|
if ( (pd[offset + 0x20] == 0xaa && pd[offset + 0x21] == 0xaa && pd[offset + 0x22] == 03) ||
|
|
(pd[offset + 0x20] == 0xe0 && pd[offset + 0x21] == 0xe0) ) {
|
|
actual_rif_bytes = 18;
|
|
} else if (
|
|
pd[offset + 0x23] == 0 &&
|
|
pd[offset + 0x24] == 0 &&
|
|
pd[offset + 0x25] == 0 &&
|
|
pd[offset + 0x26] == 0x00 &&
|
|
pd[offset + 0x27] == 0x11) {
|
|
|
|
actual_rif_bytes = 18;
|
|
|
|
/* Linux 2.0.x also requires drivers pass up
|
|
* a fake SNAP and LLC header before the
|
|
* real LLC hdr for all Token Ring frames
|
|
* that arrive with DSAP and SSAP != 0xAA
|
|
* (i.e. for non SNAP frames e.g. for Netware
|
|
* frames) the fake SNAP header has the
|
|
* ETH_P_TR_802_2 ether type (0x0011) and the protocol id
|
|
* bytes as zero frame looks like :-
|
|
* TR Header | Fake LLC | Fake SNAP | Wire LLC | Rest of data
|
|
*/
|
|
offset += 8; /* Skip fake LLC and SNAP */
|
|
}
|
|
}
|
|
}
|
|
|
|
offset += actual_rif_bytes + TR_MIN_HEADER_LEN;
|
|
|
|
/* The package is either MAC or LLC */
|
|
switch (frame_type) {
|
|
/* MAC */
|
|
case 0:
|
|
ld->other++;
|
|
break;
|
|
case 1:
|
|
capture_llc(pd, offset, len, ld);
|
|
break;
|
|
default:
|
|
/* non-MAC, non-LLC, i.e., "Reserved" */
|
|
ld->other++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
static void
|
|
dissect_tr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
proto_tree *tr_tree, *bf_tree;
|
|
proto_item *ti, *hidden_item;
|
|
guint8 rcf1, rcf2;
|
|
tvbuff_t *next_tvb;
|
|
|
|
volatile int frame_type;
|
|
volatile int fixoffset = 0;
|
|
volatile int source_routed = 0;
|
|
volatile guint8 trn_rif_bytes;
|
|
volatile guint8 actual_rif_bytes;
|
|
volatile guint8 c1_nonsr;
|
|
volatile guint8 c2_nonsr;
|
|
volatile guint16 first2_sr;
|
|
tvbuff_t *volatile tr_tvb;
|
|
|
|
static tr_hdr trh_arr[4];
|
|
static int trh_current=0;
|
|
tr_hdr *volatile trh;
|
|
|
|
/* non-source-routed version of source addr */
|
|
static guint8 trn_shost_nonsr[6];
|
|
int x;
|
|
|
|
/* Token-Ring Strings */
|
|
const char *fc[] = { "MAC", "LLC", "Reserved", "Unknown" };
|
|
|
|
|
|
trh_current++;
|
|
if(trh_current==4){
|
|
trh_current=0;
|
|
}
|
|
trh=&trh_arr[trh_current];
|
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "TR");
|
|
|
|
if (fix_linux_botches)
|
|
x = check_for_old_linux_tvb((tvbuff_t*) tvb);
|
|
else
|
|
x = 0;
|
|
if (x != 0) {
|
|
/* Actually packet starts x bytes into what we have got but with all
|
|
source routing compressed. See comment above */
|
|
tr_tvb = tvb_new_subset((tvbuff_t*) tvb, x, -1, -1);
|
|
}
|
|
else {
|
|
tr_tvb = tvb;
|
|
}
|
|
|
|
/* Get the data */
|
|
trh->fc = tvb_get_guint8(tr_tvb, 1);
|
|
SET_ADDRESS(&trh->src, AT_ETHER, 6, tvb_get_ptr(tr_tvb, 8, 6));
|
|
SET_ADDRESS(&trh->dst, AT_ETHER, 6, tvb_get_ptr(tr_tvb, 2, 6));
|
|
|
|
/* if the high bit on the first byte of src hwaddr is 1, then
|
|
this packet is source-routed */
|
|
memcpy(trn_shost_nonsr, trh->src.data, 6);
|
|
source_routed = trn_shost_nonsr[0] & 128;
|
|
trn_shost_nonsr[0] &= 127;
|
|
|
|
frame_type = (trh->fc & 192) >> 6;
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_add_fstr(pinfo->cinfo, COL_INFO, "Token-Ring %s", fc[frame_type]);
|
|
|
|
trn_rif_bytes = tvb_get_guint8(tr_tvb, 14) & 31;
|
|
|
|
if (fix_linux_botches) {
|
|
/* the Linux 2.0 TR code strips source-route bits in
|
|
* order to test for SR. This can be removed from most
|
|
* packets with oltr, but not all. So, I try to figure out
|
|
* which packets should have been SR here. I'll check to
|
|
* see if there's a SNAP or IPX field right after
|
|
* my RIF fields.
|
|
*
|
|
* The Linux 2.4.18 code, at least appears to do the
|
|
* same thing, from a capture I got from somebody running
|
|
* 2.4.18 (RH 7.1, so perhaps this is a Red Hat
|
|
* "improvement").
|
|
*/
|
|
if (frame_type == 1 && !source_routed && trn_rif_bytes > 0) {
|
|
TRY {
|
|
|
|
c1_nonsr = tvb_get_guint8(tr_tvb, 14);
|
|
c2_nonsr = tvb_get_guint8(tr_tvb, 15);
|
|
|
|
if (c1_nonsr != c2_nonsr) {
|
|
|
|
first2_sr = tvb_get_ntohs(tr_tvb, trn_rif_bytes + 0x0e);
|
|
|
|
if ( ( first2_sr == 0xaaaa &&
|
|
tvb_get_guint8(tr_tvb, trn_rif_bytes + 0x10) == 0x03) ||
|
|
|
|
first2_sr == 0xe0e0 ||
|
|
first2_sr == 0xe0aa ) {
|
|
|
|
source_routed = 1;
|
|
}
|
|
}
|
|
}
|
|
CATCH(BoundsError) {
|
|
/* We had no information beyond the TR header. Just assume
|
|
* this is a normal (non-Linux) TR header. */
|
|
;
|
|
}
|
|
ENDTRY;
|
|
}
|
|
}
|
|
|
|
if (source_routed) {
|
|
actual_rif_bytes = trn_rif_bytes;
|
|
}
|
|
else {
|
|
trn_rif_bytes = 0;
|
|
actual_rif_bytes = 0;
|
|
}
|
|
|
|
if (fix_linux_botches) {
|
|
/* this is a silly hack for Linux 2.0.x. Read the comment
|
|
* below about LLC headers. If we're sniffing our own NIC,
|
|
* we get a full RIF, sometimes with garbage
|
|
*/
|
|
TRY {
|
|
if (frame_type == 1 && ( (source_routed && trn_rif_bytes == 2) ||
|
|
!source_routed) ) {
|
|
/* look for SNAP or IPX only */
|
|
if (
|
|
(tvb_get_ntohs(tr_tvb, 0x20) == 0xaaaa &&
|
|
tvb_get_guint8(tr_tvb, 0x22) == 0x03)
|
|
||
|
|
tvb_get_ntohs(tr_tvb, 0x20) == 0xe0e0 ) {
|
|
|
|
actual_rif_bytes = 18;
|
|
}
|
|
else if (
|
|
tvb_get_ntohl(tr_tvb, 0x23) == 0 &&
|
|
tvb_get_guint8(tr_tvb, 0x27) == 0x11) {
|
|
|
|
actual_rif_bytes = 18;
|
|
|
|
/* Linux 2.0.x also requires drivers
|
|
* pass up a fake SNAP and LLC header
|
|
* before the real LLC hdr for all
|
|
* Token Ring frames that arrive with
|
|
* DSAP and SSAP != 0xAA
|
|
* (i.e. for non SNAP frames e.g. for
|
|
* Netware frames)
|
|
* the fake SNAP header has the
|
|
* ETH_P_TR_802_2 ether type (0x0011)
|
|
* and the protocol id bytes as zero frame looks like :-
|
|
* TR Header | Fake LLC | Fake SNAP | Wire LLC | Rest of data
|
|
*/
|
|
fixoffset += 8; /* Skip fake LLC and SNAP */
|
|
}
|
|
}
|
|
}
|
|
CATCH(BoundsError) {
|
|
/* We had no information beyond the TR header. Just assume
|
|
* this is a normal (non-Linux) TR header. */
|
|
;
|
|
}
|
|
ENDTRY;
|
|
}
|
|
|
|
/* XXX - copy it to some buffer associated with "*pinfo", rather than
|
|
just making "trn_shost_nonsr" static? */
|
|
SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, trn_shost_nonsr);
|
|
SET_ADDRESS(&pinfo->src, AT_ETHER, 6, trn_shost_nonsr);
|
|
SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, trh->dst.data);
|
|
SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, trh->dst.data);
|
|
|
|
/* protocol analysis tree */
|
|
if (tree) {
|
|
/* Create Token-Ring Tree */
|
|
ti = proto_tree_add_item(tree, proto_tr, tr_tvb, 0, TR_MIN_HEADER_LEN + actual_rif_bytes, FALSE);
|
|
tr_tree = proto_item_add_subtree(ti, ett_token_ring);
|
|
|
|
/* Create the Access Control bitfield tree */
|
|
trh->ac = tvb_get_guint8(tr_tvb, 0);
|
|
ti = proto_tree_add_uint(tr_tree, hf_tr_ac, tr_tvb, 0, 1, trh->ac);
|
|
bf_tree = proto_item_add_subtree(ti, ett_token_ring_ac);
|
|
|
|
proto_tree_add_uint(bf_tree, hf_tr_priority, tr_tvb, 0, 1, trh->ac);
|
|
proto_tree_add_boolean(bf_tree, hf_tr_frame, tr_tvb, 0, 1, trh->ac);
|
|
proto_tree_add_uint(bf_tree, hf_tr_monitor_cnt, tr_tvb, 0, 1, trh->ac);
|
|
proto_tree_add_uint(bf_tree, hf_tr_priority_reservation, tr_tvb, 0, 1, trh->ac);
|
|
|
|
/* Create the Frame Control bitfield tree */
|
|
ti = proto_tree_add_uint(tr_tree, hf_tr_fc, tr_tvb, 1, 1, trh->fc);
|
|
bf_tree = proto_item_add_subtree(ti, ett_token_ring_fc);
|
|
|
|
proto_tree_add_uint(bf_tree, hf_tr_fc_type, tr_tvb, 1, 1, trh->fc);
|
|
proto_tree_add_uint(bf_tree, hf_tr_fc_pcf, tr_tvb, 1, 1, trh->fc);
|
|
proto_tree_add_ether(tr_tree, hf_tr_dst, tr_tvb, 2, 6, trh->dst.data);
|
|
proto_tree_add_ether(tr_tree, hf_tr_src, tr_tvb, 8, 6, trh->src.data);
|
|
hidden_item = proto_tree_add_ether(tr_tree, hf_tr_addr, tr_tvb, 2, 6, trh->dst.data);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
hidden_item = proto_tree_add_ether(tr_tree, hf_tr_addr, tr_tvb, 8, 6, trh->src.data);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
|
|
proto_tree_add_boolean(tr_tree, hf_tr_sr, tr_tvb, 8, 1, source_routed);
|
|
|
|
/* non-source-routed version of src addr */
|
|
hidden_item = proto_tree_add_ether(tr_tree, hf_tr_src, tr_tvb, 8, 6, trn_shost_nonsr);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
|
|
if (source_routed) {
|
|
/* RCF Byte 1 */
|
|
rcf1 = tvb_get_guint8(tr_tvb, 14);
|
|
proto_tree_add_uint(tr_tree, hf_tr_rif_bytes, tr_tvb, 14, 1, trn_rif_bytes);
|
|
proto_tree_add_uint(tr_tree, hf_tr_broadcast, tr_tvb, 14, 1, rcf1 & 224);
|
|
|
|
/* RCF Byte 2 */
|
|
rcf2 = tvb_get_guint8(tr_tvb, 15);
|
|
proto_tree_add_uint(tr_tree, hf_tr_max_frame_size, tr_tvb, 15, 1, rcf2 & 112);
|
|
proto_tree_add_uint(tr_tree, hf_tr_direction, tr_tvb, 15, 1, rcf2 & 128);
|
|
|
|
/* if we have more than 2 bytes of RIF, then we have
|
|
ring/bridge pairs */
|
|
if (trn_rif_bytes > 2) {
|
|
add_ring_bridge_pairs(trn_rif_bytes, tr_tvb, tr_tree);
|
|
}
|
|
}
|
|
|
|
/* Linux 2.0.x has a problem in that the 802.5 code creates
|
|
an emtpy full (18-byte) RIF area. It's up to the tr driver to
|
|
either fill it in or remove it before sending the bytes out
|
|
to the wire. If you run tcpdump on a Linux 2.0.x machine running
|
|
token-ring, tcpdump will capture these 18 filler bytes. They
|
|
are filled with garbage. The best way to detect this problem is
|
|
to know the src hwaddr of the machine from which you were running
|
|
tcpdump. W/o that, however, I'm guessing that DSAP == SSAP if the
|
|
frame type is LLC. It's very much a hack. */
|
|
if (actual_rif_bytes > trn_rif_bytes) {
|
|
proto_tree_add_text(tr_tree, tr_tvb, TR_MIN_HEADER_LEN + trn_rif_bytes, actual_rif_bytes - trn_rif_bytes,
|
|
"Empty RIF from Linux 2.0.x driver. The sniffing NIC "
|
|
"is also running a protocol stack.");
|
|
}
|
|
if (fixoffset) {
|
|
proto_tree_add_text(tr_tree, tr_tvb, TR_MIN_HEADER_LEN + 18,8,"Linux 2.0.x fake LLC and SNAP header");
|
|
}
|
|
}
|
|
|
|
next_tvb = tvb_new_subset_remaining(tr_tvb, TR_MIN_HEADER_LEN + actual_rif_bytes + fixoffset);
|
|
|
|
/* The package is either MAC or LLC */
|
|
switch (frame_type) {
|
|
/* MAC */
|
|
case 0:
|
|
call_dissector(trmac_handle, next_tvb, pinfo, tree);
|
|
break;
|
|
case 1:
|
|
call_dissector(llc_handle, next_tvb, pinfo, tree);
|
|
break;
|
|
default:
|
|
/* non-MAC, non-LLC, i.e., "Reserved" */
|
|
call_dissector(data_handle,next_tvb, pinfo, tree);
|
|
break;
|
|
}
|
|
|
|
tap_queue_packet(tr_tap, pinfo, trh);
|
|
}
|
|
|
|
/* this routine is taken from the Linux net/802/tr.c code, which shows
|
|
ring-bridge pairs in the /proc/net/tr_rif virtual file. */
|
|
static void
|
|
add_ring_bridge_pairs(int rcf_len, tvbuff_t *tvb, proto_tree *tree)
|
|
{
|
|
proto_item *hidden_item;
|
|
int j, size;
|
|
int segment, brdgnmb, unprocessed_rif;
|
|
int buff_offset=0;
|
|
|
|
#define RIF_OFFSET 16
|
|
#define RIF_BYTES_TO_PROCESS 30
|
|
|
|
char *buffer;
|
|
#define MAX_BUF_LEN 3 + (RIF_BYTES_TO_PROCESS / 2) * 6 + 1
|
|
|
|
buffer=ep_alloc(MAX_BUF_LEN);
|
|
/* Only process so many bytes of RIF, as per TR spec, and not overflow
|
|
* static buffer above */
|
|
unprocessed_rif = rcf_len - RIF_BYTES_TO_PROCESS;
|
|
rcf_len = MIN(rcf_len, RIF_BYTES_TO_PROCESS);
|
|
|
|
/* Ignore the 2 RCF bytes, since they don't make up the ring/bride pairs */
|
|
rcf_len -= 2;
|
|
|
|
for(j = 1; j < rcf_len - 1; j += 2) {
|
|
if (j==1) {
|
|
segment = tvb_get_ntohs(tvb, RIF_OFFSET) >> 4;
|
|
size = g_snprintf(buffer, MAX_BUF_LEN, "%03X",segment);
|
|
size = MIN(size, MAX_BUF_LEN - 1);
|
|
hidden_item = proto_tree_add_uint(tree, hf_tr_rif_ring, tvb, TR_MIN_HEADER_LEN + 2, 2, segment);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
buff_offset += size;
|
|
}
|
|
segment = tvb_get_ntohs(tvb, RIF_OFFSET + 1 + j) >> 4;
|
|
brdgnmb = tvb_get_guint8(tvb, RIF_OFFSET + j) & 0x0f;
|
|
size = g_snprintf(buffer+buff_offset, MAX_BUF_LEN-buff_offset, "-%01X-%03X",brdgnmb,segment);
|
|
size = MIN(size, MAX_BUF_LEN-buff_offset-1);
|
|
hidden_item = proto_tree_add_uint(tree, hf_tr_rif_ring, tvb, TR_MIN_HEADER_LEN + 3 + j, 2, segment);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
hidden_item = proto_tree_add_uint(tree, hf_tr_rif_bridge, tvb, TR_MIN_HEADER_LEN + 2 + j, 1, brdgnmb);
|
|
PROTO_ITEM_SET_HIDDEN(hidden_item);
|
|
buff_offset += size;
|
|
}
|
|
proto_tree_add_string(tree, hf_tr_rif, tvb, TR_MIN_HEADER_LEN + 2, rcf_len, buffer);
|
|
|
|
if (unprocessed_rif > 0) {
|
|
proto_tree_add_text(tree, tvb, TR_MIN_HEADER_LEN + RIF_BYTES_TO_PROCESS, unprocessed_rif,
|
|
"Extra RIF bytes beyond spec: %d", unprocessed_rif);
|
|
}
|
|
}
|
|
|
|
void
|
|
proto_register_tr(void)
|
|
{
|
|
static hf_register_info hf[] = {
|
|
{ &hf_tr_ac,
|
|
{ "Access Control", "tr.ac", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_priority,
|
|
{ "Priority", "tr.priority", FT_UINT8, BASE_DEC, NULL, 0xe0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_frame,
|
|
{ "Frame", "tr.frame", FT_BOOLEAN, 8, TFS(&ac_truth), 0x10,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_monitor_cnt,
|
|
{ "Monitor Count", "tr.monitor_cnt", FT_UINT8, BASE_DEC, NULL, 0x08,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_priority_reservation,
|
|
{ "Priority Reservation","tr.priority_reservation", FT_UINT8, BASE_DEC, NULL, 0x07,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_fc,
|
|
{ "Frame Control", "tr.fc", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_fc_type,
|
|
{ "Frame Type", "tr.frame_type", FT_UINT8, BASE_DEC, VALS(frame_vals), 0xc0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_fc_pcf,
|
|
{ "Frame PCF", "tr.frame_pcf", FT_UINT8, BASE_DEC, VALS(pcf_vals), 0x0f,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_dst,
|
|
{ "Destination", "tr.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Destination Hardware Address", HFILL }},
|
|
|
|
{ &hf_tr_src,
|
|
{ "Source", "tr.src", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Source Hardware Address", HFILL }},
|
|
|
|
{ &hf_tr_addr,
|
|
{ "Source or Destination Address", "tr.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
|
|
"Source or Destination Hardware Address", HFILL }},
|
|
|
|
{ &hf_tr_sr,
|
|
{ "Source Routed", "tr.sr", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_rif_bytes,
|
|
{ "RIF Bytes", "tr.rif_bytes", FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"Number of bytes in Routing Information Fields, including the two bytes of Routing Control Field", HFILL }},
|
|
|
|
{ &hf_tr_broadcast,
|
|
{ "Broadcast Type", "tr.broadcast", FT_UINT8, BASE_DEC, VALS(broadcast_vals), 0x0,
|
|
"Type of Token-Ring Broadcast", HFILL }},
|
|
|
|
{ &hf_tr_max_frame_size,
|
|
{ "Maximum Frame Size", "tr.max_frame_size", FT_UINT8, BASE_DEC, VALS(max_frame_size_vals),
|
|
0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_direction,
|
|
{ "Direction", "tr.direction", FT_UINT8, BASE_DEC, VALS(direction_vals), 0x0,
|
|
"Direction of RIF", HFILL }},
|
|
|
|
{ &hf_tr_rif,
|
|
{ "Ring-Bridge Pairs", "tr.rif", FT_STRING, BASE_NONE, NULL, 0x0,
|
|
"String representing Ring-Bridge Pairs", HFILL }},
|
|
|
|
{ &hf_tr_rif_ring,
|
|
{ "RIF Ring", "tr.rif.ring", FT_UINT16, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
|
|
{ &hf_tr_rif_bridge,
|
|
{ "RIF Bridge", "tr.rif.bridge", FT_UINT8, BASE_HEX, NULL, 0x0,
|
|
NULL, HFILL }},
|
|
};
|
|
static gint *ett[] = {
|
|
&ett_token_ring,
|
|
&ett_token_ring_ac,
|
|
&ett_token_ring_fc,
|
|
};
|
|
module_t *tr_module;
|
|
|
|
proto_tr = proto_register_protocol("Token-Ring", "Token-Ring", "tr");
|
|
proto_register_field_array(proto_tr, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
/* Register configuration options */
|
|
tr_module = prefs_register_protocol(proto_tr, NULL);
|
|
prefs_register_bool_preference(tr_module, "fix_linux_botches",
|
|
"Attempt to compensate for Linux mangling of the link-layer header",
|
|
"Whether Linux mangling of the link-layer header should be checked for and worked around",
|
|
&fix_linux_botches);
|
|
|
|
register_dissector("tr", dissect_tr, proto_tr);
|
|
tr_tap=register_tap("tr");
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_tr(void)
|
|
{
|
|
dissector_handle_t tr_handle;
|
|
|
|
/*
|
|
* Get handles for the TR MAC and LLC dissectors.
|
|
*/
|
|
trmac_handle = find_dissector("trmac");
|
|
llc_handle = find_dissector("llc");
|
|
data_handle = find_dissector("data");
|
|
|
|
tr_handle = find_dissector("tr");
|
|
dissector_add_uint("wtap_encap", WTAP_ENCAP_TOKEN_RING, tr_handle);
|
|
}
|