2 * Routines for Token-Ring packet disassembly
3 * Gilbert Ramirez <gram@alumni.rice.edu>
7 * Wireshark - Network traffic analyzer
8 * By Gerald Combs <gerald@wireshark.org>
9 * Copyright 1998 Gerald Combs
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
33 #include <epan/packet.h>
34 #include "packet-tr.h"
35 #include "packet-llc.h"
36 #include <epan/prefs.h>
38 #include <epan/emem.h>
40 static int proto_tr = -1;
41 static int hf_tr_dst = -1;
42 static int hf_tr_src = -1;
43 static int hf_tr_addr = -1;
44 static int hf_tr_sr = -1;
45 static int hf_tr_ac = -1;
46 static int hf_tr_priority = -1;
47 static int hf_tr_frame = -1;
48 static int hf_tr_monitor_cnt = -1;
49 static int hf_tr_priority_reservation = -1;
50 static int hf_tr_fc = -1;
51 static int hf_tr_fc_type = -1;
52 static int hf_tr_fc_pcf = -1;
53 static int hf_tr_rif_bytes = -1;
54 static int hf_tr_broadcast = -1;
55 static int hf_tr_max_frame_size = -1;
56 static int hf_tr_direction = -1;
57 static int hf_tr_rif = -1;
58 static int hf_tr_rif_ring = -1;
59 static int hf_tr_rif_bridge = -1;
61 static gint ett_token_ring = -1;
62 static gint ett_token_ring_ac = -1;
63 static gint ett_token_ring_fc = -1;
65 static int tr_tap = -1;
68 * Check for and attempt to fix Linux link-layer header mangling.
70 static gboolean fix_linux_botches = FALSE;
72 #define TR_MIN_HEADER_LEN 14
73 #define TR_MAX_HEADER_LEN 32
75 static const true_false_string ac_truth = { "Frame", "Token" };
77 static const value_string pcf_vals[] = {
78 { 0, "Normal buffer" },
79 { 1, "Express buffer" },
83 { 5, "Active Monitor Present" },
84 { 6, "Standby Monitor Present" },
88 static const value_string frame_vals[] = {
95 static const value_string broadcast_vals[] = {
96 { 0 << 5, "Non-broadcast" },
97 { 1 << 5, "Non-broadcast" },
98 { 2 << 5, "Non-broadcast" },
99 { 3 << 5, "Non-broadcast" },
100 { 4 << 5, "All-routes broadcast" },
101 { 5 << 5, "All-routes broadcast" },
102 { 6 << 5, "Single-route broadcast" },
103 { 7 << 5, "Single-route broadcast" },
107 static const value_string max_frame_size_vals[] = {
119 static const value_string direction_vals[] = {
120 { 0, "From originating station (-->)" },
121 { 128, "To originating station (<--)" },
125 static dissector_handle_t trmac_handle;
126 static dissector_handle_t llc_handle;
127 static dissector_handle_t data_handle;
130 * DODGY LINUX HACK DODGY LINUX HACK
131 * Linux 2.0.x always passes frames to the Token Ring driver for transmission with
132 * 18 bytes padding for source routing information. Some drivers copy the first
133 * (18 - srlen) bytes up the frame (18 - srlen) bytes thus removing the padding.
134 * Other drivers just make a copy of the entire frame and then hack about with it
135 * so the frame the sniffer gets is fine (just has extra sr routing).
136 * In the first instance (driver hacking frame in situ) the sniffer gets a garbled
138 * This function trys to detect this and returns the offset of where
139 * the frame really starts.
140 * This only detects frames that we have sent ourselves so if we are packet sniffing
141 * on the machine we are watching this is useful.
142 * Compare offset 0 with offset x+1 for a length of x bytes for all value of x = 1 to 18
143 * if match then Linux driver has done in situ source route compression of the crappy
144 * Linux 2.0.x frame so the beginning of the real frame is x bytes in.
145 * (And this real frame x bytes in looks like a proper TR frame that goes on the wire
146 * with none of the Linux idiosyncrasies).
148 * XXX - there should perhaps be a preference setting to turn this off,
149 * as sometimes it can, and does, get a false hit.
152 int check_for_old_linux_tvb(tvbuff_t *tvb)
157 /* Restrict our looping to the boundaries of the frame */
158 bytes = tvb_length(tvb);
163 data = tvb_get_ptr(tvb, 0, bytes);
165 for(x = 1; x <= bytes-1 ;x++)
167 if (memcmp(&data[0], &data[x], x) == 0)
176 int check_for_old_linux(const guchar * pd)
181 if (memcmp(&pd[0],&pd[x],x) == 0)
191 add_ring_bridge_pairs(int rcf_len, tvbuff_t*, proto_tree *tree);
194 capture_tr(const guchar *pd, int offset, int len, packet_counts *ld) {
196 int source_routed = 0;
199 guint8 trn_rif_bytes;
200 guint8 actual_rif_bytes;
203 /* The trn_hdr struct, as separate variables */
204 guint8 trn_fc; /* field control field */
205 const guint8 *trn_shost; /* source host */
207 if (!BYTES_ARE_IN_FRAME(offset, len, TR_MIN_HEADER_LEN)) {
212 if ((x = check_for_old_linux(pd)))
214 /* Actually packet starts x bytes into what we have got but with all
215 source routing compressed
217 /* pd = &pd[x]; */ offset+=x;
221 trn_fc = pd[offset + 1];
222 trn_shost = &pd[offset + 8];
224 frame_type = (trn_fc & 192) >> 6;
226 /* if the high bit on the first byte of src hwaddr is 1, then
227 this packet is source-routed */
228 source_routed = trn_shost[0] & 128;
230 trn_rif_bytes = pd[offset + 14] & 31;
232 if (fix_linux_botches) {
233 /* the Linux 2.0 TR code strips source-route bits in
234 * order to test for SR. This can be removed from most
235 * packets with oltr, but not all. So, I try to figure out
236 * which packets should have been SR here. I'll check to
237 * see if there's a SNAP or IPX field right after
240 * The Linux 2.4.18 code, at least appears to do the
241 * same thing, from a capture I got from somebody running
242 * 2.4.18 (RH 7.1, so perhaps this is a Red Hat
245 if (!source_routed && trn_rif_bytes > 0) {
246 if (pd[offset + 0x0e] != pd[offset + 0x0f]) {
247 first2_sr = pntohs(&pd[offset + 0xe0 + trn_rif_bytes]);
249 (first2_sr == 0xaaaa &&
250 pd[offset + 0x10 + trn_rif_bytes] == 0x03) ||
252 first2_sr == 0xe0e0 ||
253 first2_sr == 0xe0aa ) {
262 actual_rif_bytes = trn_rif_bytes;
266 actual_rif_bytes = 0;
269 if (fix_linux_botches) {
270 /* this is a silly hack for Linux 2.0.x. Read the comment
271 * below, in front of the other #ifdef linux.
272 * If we're sniffing our own NIC, we get a full RIF,
273 * sometimes with garbage
275 if ((source_routed && trn_rif_bytes == 2 && frame_type == 1) ||
276 (!source_routed && frame_type == 1)) {
277 /* look for SNAP or IPX only */
278 if ( (pd[offset + 0x20] == 0xaa && pd[offset + 0x21] == 0xaa && pd[offset + 0x22] == 03) ||
279 (pd[offset + 0x20] == 0xe0 && pd[offset + 0x21] == 0xe0) ) {
280 actual_rif_bytes = 18;
282 pd[offset + 0x23] == 0 &&
283 pd[offset + 0x24] == 0 &&
284 pd[offset + 0x25] == 0 &&
285 pd[offset + 0x26] == 0x00 &&
286 pd[offset + 0x27] == 0x11) {
288 actual_rif_bytes = 18;
290 /* Linux 2.0.x also requires drivers pass up
291 * a fake SNAP and LLC header before the
292 * real LLC hdr for all Token Ring frames
293 * that arrive with DSAP and SSAP != 0xAA
294 * (i.e. for non SNAP frames e.g. for Netware
295 * frames) the fake SNAP header has the
296 * ETH_P_TR_802_2 ether type (0x0011) and the protocol id
297 * bytes as zero frame looks like :-
298 * TR Header | Fake LLC | Fake SNAP | Wire LLC | Rest of data
300 offset += 8; /* Skip fake LLC and SNAP */
305 offset += actual_rif_bytes + TR_MIN_HEADER_LEN;
307 /* The package is either MAC or LLC */
308 switch (frame_type) {
314 capture_llc(pd, offset, len, ld);
317 /* non-MAC, non-LLC, i.e., "Reserved" */
325 dissect_tr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
327 proto_tree *tr_tree, *bf_tree;
328 proto_item *ti, *hidden_item;
332 volatile int frame_type;
333 volatile int fixoffset = 0;
334 volatile int source_routed = 0;
335 volatile guint8 trn_rif_bytes;
336 volatile guint8 actual_rif_bytes;
337 volatile guint8 c1_nonsr;
338 volatile guint8 c2_nonsr;
339 volatile guint16 first2_sr;
340 tvbuff_t *volatile tr_tvb;
342 static tr_hdr trh_arr[4];
343 static int trh_current=0;
344 tr_hdr *volatile trh;
346 /* non-source-routed version of source addr */
347 static guint8 trn_shost_nonsr[6];
350 /* Token-Ring Strings */
351 const char *fc[] = { "MAC", "LLC", "Reserved", "Unknown" };
358 trh=&trh_arr[trh_current];
360 if (check_col(pinfo->cinfo, COL_PROTOCOL))
361 col_set_str(pinfo->cinfo, COL_PROTOCOL, "TR");
363 if (fix_linux_botches)
364 x = check_for_old_linux_tvb((tvbuff_t*) tvb);
368 /* Actually packet starts x bytes into what we have got but with all
369 source routing compressed. See comment above */
370 tr_tvb = tvb_new_subset((tvbuff_t*) tvb, x, -1, -1);
377 trh->fc = tvb_get_guint8(tr_tvb, 1);
378 SET_ADDRESS(&trh->src, AT_ETHER, 6, tvb_get_ptr(tr_tvb, 8, 6));
379 SET_ADDRESS(&trh->dst, AT_ETHER, 6, tvb_get_ptr(tr_tvb, 2, 6));
381 /* if the high bit on the first byte of src hwaddr is 1, then
382 this packet is source-routed */
383 memcpy(trn_shost_nonsr, trh->src.data, 6);
384 source_routed = trn_shost_nonsr[0] & 128;
385 trn_shost_nonsr[0] &= 127;
387 frame_type = (trh->fc & 192) >> 6;
389 if (check_col(pinfo->cinfo, COL_INFO))
390 col_add_fstr(pinfo->cinfo, COL_INFO, "Token-Ring %s", fc[frame_type]);
392 trn_rif_bytes = tvb_get_guint8(tr_tvb, 14) & 31;
394 if (fix_linux_botches) {
395 /* the Linux 2.0 TR code strips source-route bits in
396 * order to test for SR. This can be removed from most
397 * packets with oltr, but not all. So, I try to figure out
398 * which packets should have been SR here. I'll check to
399 * see if there's a SNAP or IPX field right after
402 * The Linux 2.4.18 code, at least appears to do the
403 * same thing, from a capture I got from somebody running
404 * 2.4.18 (RH 7.1, so perhaps this is a Red Hat
407 if (frame_type == 1 && !source_routed && trn_rif_bytes > 0) {
410 c1_nonsr = tvb_get_guint8(tr_tvb, 14);
411 c2_nonsr = tvb_get_guint8(tr_tvb, 15);
413 if (c1_nonsr != c2_nonsr) {
415 first2_sr = tvb_get_ntohs(tr_tvb, trn_rif_bytes + 0x0e);
417 if ( ( first2_sr == 0xaaaa &&
418 tvb_get_guint8(tr_tvb, trn_rif_bytes + 0x10) == 0x03) ||
420 first2_sr == 0xe0e0 ||
421 first2_sr == 0xe0aa ) {
428 /* We had no information beyond the TR header. Just assume
429 * this is a normal (non-Linux) TR header. */
437 actual_rif_bytes = trn_rif_bytes;
441 actual_rif_bytes = 0;
444 if (fix_linux_botches) {
445 /* this is a silly hack for Linux 2.0.x. Read the comment
446 * below, in front of the other #ifdef linux. If we're
447 * sniffing our own NIC, we get a full RIF, sometimes with
451 if (frame_type == 1 && ( (source_routed && trn_rif_bytes == 2) ||
453 /* look for SNAP or IPX only */
455 (tvb_get_ntohs(tr_tvb, 0x20) == 0xaaaa &&
456 tvb_get_guint8(tr_tvb, 0x22) == 0x03)
458 tvb_get_ntohs(tr_tvb, 0x20) == 0xe0e0 ) {
460 actual_rif_bytes = 18;
463 tvb_get_ntohl(tr_tvb, 0x23) == 0 &&
464 tvb_get_guint8(tr_tvb, 0x27) == 0x11) {
466 actual_rif_bytes = 18;
468 /* Linux 2.0.x also requires drivers
469 * pass up a fake SNAP and LLC header
470 * before the real LLC hdr for all
471 * Token Ring frames that arrive with
472 * DSAP and SSAP != 0xAA
473 * (i.e. for non SNAP frames e.g. for
475 * the fake SNAP header has the
476 * ETH_P_TR_802_2 ether type (0x0011)
477 * and the protocol id bytes as zero frame looks like :-
478 * TR Header | Fake LLC | Fake SNAP | Wire LLC | Rest of data
480 fixoffset += 8; /* Skip fake LLC and SNAP */
485 /* We had no information beyond the TR header. Just assume
486 * this is a normal (non-Linux) TR header. */
492 /* XXX - copy it to some buffer associated with "*pinfo", rather than
493 just making "trn_shost_nonsr" static? */
494 SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, trn_shost_nonsr);
495 SET_ADDRESS(&pinfo->src, AT_ETHER, 6, trn_shost_nonsr);
496 SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, trh->dst.data);
497 SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, trh->dst.data);
499 /* protocol analysis tree */
501 /* Create Token-Ring Tree */
502 ti = proto_tree_add_item(tree, proto_tr, tr_tvb, 0, TR_MIN_HEADER_LEN + actual_rif_bytes, FALSE);
503 tr_tree = proto_item_add_subtree(ti, ett_token_ring);
505 /* Create the Access Control bitfield tree */
506 trh->ac = tvb_get_guint8(tr_tvb, 0);
507 ti = proto_tree_add_uint(tr_tree, hf_tr_ac, tr_tvb, 0, 1, trh->ac);
508 bf_tree = proto_item_add_subtree(ti, ett_token_ring_ac);
510 proto_tree_add_uint(bf_tree, hf_tr_priority, tr_tvb, 0, 1, trh->ac);
511 proto_tree_add_boolean(bf_tree, hf_tr_frame, tr_tvb, 0, 1, trh->ac);
512 proto_tree_add_uint(bf_tree, hf_tr_monitor_cnt, tr_tvb, 0, 1, trh->ac);
513 proto_tree_add_uint(bf_tree, hf_tr_priority_reservation, tr_tvb, 0, 1, trh->ac);
515 /* Create the Frame Control bitfield tree */
516 ti = proto_tree_add_uint(tr_tree, hf_tr_fc, tr_tvb, 1, 1, trh->fc);
517 bf_tree = proto_item_add_subtree(ti, ett_token_ring_fc);
519 proto_tree_add_uint(bf_tree, hf_tr_fc_type, tr_tvb, 1, 1, trh->fc);
520 proto_tree_add_uint(bf_tree, hf_tr_fc_pcf, tr_tvb, 1, 1, trh->fc);
521 proto_tree_add_ether(tr_tree, hf_tr_dst, tr_tvb, 2, 6, trh->dst.data);
522 proto_tree_add_ether(tr_tree, hf_tr_src, tr_tvb, 8, 6, trh->src.data);
523 hidden_item = proto_tree_add_ether(tr_tree, hf_tr_addr, tr_tvb, 2, 6, trh->dst.data);
524 PROTO_ITEM_SET_HIDDEN(hidden_item);
525 hidden_item = proto_tree_add_ether(tr_tree, hf_tr_addr, tr_tvb, 8, 6, trh->src.data);
526 PROTO_ITEM_SET_HIDDEN(hidden_item);
528 proto_tree_add_boolean(tr_tree, hf_tr_sr, tr_tvb, 8, 1, source_routed);
530 /* non-source-routed version of src addr */
531 hidden_item = proto_tree_add_ether(tr_tree, hf_tr_src, tr_tvb, 8, 6, trn_shost_nonsr);
532 PROTO_ITEM_SET_HIDDEN(hidden_item);
536 rcf1 = tvb_get_guint8(tr_tvb, 14);
537 proto_tree_add_uint(tr_tree, hf_tr_rif_bytes, tr_tvb, 14, 1, trn_rif_bytes);
538 proto_tree_add_uint(tr_tree, hf_tr_broadcast, tr_tvb, 14, 1, rcf1 & 224);
541 rcf2 = tvb_get_guint8(tr_tvb, 15);
542 proto_tree_add_uint(tr_tree, hf_tr_max_frame_size, tr_tvb, 15, 1, rcf2 & 112);
543 proto_tree_add_uint(tr_tree, hf_tr_direction, tr_tvb, 15, 1, rcf2 & 128);
545 /* if we have more than 2 bytes of RIF, then we have
547 if (trn_rif_bytes > 2) {
548 add_ring_bridge_pairs(trn_rif_bytes, tr_tvb, tr_tree);
552 /* Linux 2.0.x has a problem in that the 802.5 code creates
553 an emtpy full (18-byte) RIF area. It's up to the tr driver to
554 either fill it in or remove it before sending the bytes out
555 to the wire. If you run tcpdump on a Linux 2.0.x machine running
556 token-ring, tcpdump will capture these 18 filler bytes. They
557 are filled with garbage. The best way to detect this problem is
558 to know the src hwaddr of the machine from which you were running
559 tcpdump. W/o that, however, I'm guessing that DSAP == SSAP if the
560 frame type is LLC. It's very much a hack. */
561 if (actual_rif_bytes > trn_rif_bytes) {
562 proto_tree_add_text(tr_tree, tr_tvb, TR_MIN_HEADER_LEN + trn_rif_bytes, actual_rif_bytes - trn_rif_bytes,
563 "Empty RIF from Linux 2.0.x driver. The sniffing NIC "
564 "is also running a protocol stack.");
567 proto_tree_add_text(tr_tree, tr_tvb, TR_MIN_HEADER_LEN + 18,8,"Linux 2.0.x fake LLC and SNAP header");
571 next_tvb = tvb_new_subset(tr_tvb, TR_MIN_HEADER_LEN + actual_rif_bytes + fixoffset, -1, -1);
573 /* The package is either MAC or LLC */
574 switch (frame_type) {
577 call_dissector(trmac_handle, next_tvb, pinfo, tree);
580 call_dissector(llc_handle, next_tvb, pinfo, tree);
583 /* non-MAC, non-LLC, i.e., "Reserved" */
584 call_dissector(data_handle,next_tvb, pinfo, tree);
588 tap_queue_packet(tr_tap, pinfo, trh);
591 /* this routine is taken from the Linux net/802/tr.c code, which shows
592 ring-bridge pairs in the /proc/net/tr_rif virtual file. */
594 add_ring_bridge_pairs(int rcf_len, tvbuff_t *tvb, proto_tree *tree)
596 proto_item *hidden_item;
598 int segment, brdgnmb, unprocessed_rif;
601 #define RIF_OFFSET 16
602 #define RIF_BYTES_TO_PROCESS 30
605 #define MAX_BUF_LEN 3 + (RIF_BYTES_TO_PROCESS / 2) * 6 + 1
607 buffer=ep_alloc(MAX_BUF_LEN);
608 /* Only process so many bytes of RIF, as per TR spec, and not overflow
609 * static buffer above */
610 unprocessed_rif = rcf_len - RIF_BYTES_TO_PROCESS;
611 rcf_len = MIN(rcf_len, RIF_BYTES_TO_PROCESS);
613 /* Ignore the 2 RCF bytes, since they don't make up the ring/bride pairs */
616 for(j = 1; j < rcf_len - 1; j += 2) {
618 segment = tvb_get_ntohs(tvb, RIF_OFFSET) >> 4;
619 size = g_snprintf(buffer, MAX_BUF_LEN, "%03X",segment);
620 size = MIN(size, MAX_BUF_LEN - 1);
621 hidden_item = proto_tree_add_uint(tree, hf_tr_rif_ring, tvb, TR_MIN_HEADER_LEN + 2, 2, segment);
622 PROTO_ITEM_SET_HIDDEN(hidden_item);
625 segment = tvb_get_ntohs(tvb, RIF_OFFSET + 1 + j) >> 4;
626 brdgnmb = tvb_get_guint8(tvb, RIF_OFFSET + j) & 0x0f;
627 size = g_snprintf(buffer+buff_offset, MAX_BUF_LEN-buff_offset, "-%01X-%03X",brdgnmb,segment);
628 size = MIN(size, MAX_BUF_LEN-buff_offset-1);
629 hidden_item = proto_tree_add_uint(tree, hf_tr_rif_ring, tvb, TR_MIN_HEADER_LEN + 3 + j, 2, segment);
630 PROTO_ITEM_SET_HIDDEN(hidden_item);
631 hidden_item = proto_tree_add_uint(tree, hf_tr_rif_bridge, tvb, TR_MIN_HEADER_LEN + 2 + j, 1, brdgnmb);
632 PROTO_ITEM_SET_HIDDEN(hidden_item);
635 proto_tree_add_string(tree, hf_tr_rif, tvb, TR_MIN_HEADER_LEN + 2, rcf_len, buffer);
637 if (unprocessed_rif > 0) {
638 proto_tree_add_text(tree, tvb, TR_MIN_HEADER_LEN + RIF_BYTES_TO_PROCESS, unprocessed_rif,
639 "Extra RIF bytes beyond spec: %d", unprocessed_rif);
644 proto_register_tr(void)
646 static hf_register_info hf[] = {
648 { "Access Control", "tr.ac", FT_UINT8, BASE_HEX, NULL, 0x0,
652 { "Priority", "tr.priority", FT_UINT8, BASE_DEC, NULL, 0xe0,
656 { "Frame", "tr.frame", FT_BOOLEAN, 8, TFS(&ac_truth), 0x10,
659 { &hf_tr_monitor_cnt,
660 { "Monitor Count", "tr.monitor_cnt", FT_UINT8, BASE_DEC, NULL, 0x08,
663 { &hf_tr_priority_reservation,
664 { "Priority Reservation","tr.priority_reservation", FT_UINT8, BASE_DEC, NULL, 0x07,
668 { "Frame Control", "tr.fc", FT_UINT8, BASE_HEX, NULL, 0x0,
672 { "Frame Type", "tr.frame_type", FT_UINT8, BASE_DEC, VALS(frame_vals), 0xc0,
676 { "Frame PCF", "tr.frame_pcf", FT_UINT8, BASE_DEC, VALS(pcf_vals), 0x0f,
680 { "Destination", "tr.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
681 "Destination Hardware Address", HFILL }},
684 { "Source", "tr.src", FT_ETHER, BASE_NONE, NULL, 0x0,
685 "Source Hardware Address", HFILL }},
688 { "Source or Destination Address", "tr.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
689 "Source or Destination Hardware Address", HFILL }},
692 { "Source Routed", "tr.sr", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
693 "Source Routed", HFILL }},
696 { "RIF Bytes", "tr.rif_bytes", FT_UINT8, BASE_DEC, NULL, 0x0,
697 "Number of bytes in Routing Information Fields, including "
698 "the two bytes of Routing Control Field", HFILL }},
701 { "Broadcast Type", "tr.broadcast", FT_UINT8, BASE_DEC, VALS(broadcast_vals), 0x0,
702 "Type of Token-Ring Broadcast", HFILL }},
704 { &hf_tr_max_frame_size,
705 { "Maximum Frame Size", "tr.max_frame_size", FT_UINT8, BASE_DEC, VALS(max_frame_size_vals),
710 { "Direction", "tr.direction", FT_UINT8, BASE_DEC, VALS(direction_vals), 0x0,
711 "Direction of RIF", HFILL }},
714 { "Ring-Bridge Pairs", "tr.rif", FT_STRING, BASE_NONE, NULL, 0x0,
715 "String representing Ring-Bridge Pairs", HFILL }},
718 { "RIF Ring", "tr.rif.ring", FT_UINT16, BASE_HEX, NULL, 0x0,
722 { "RIF Bridge", "tr.rif.bridge", FT_UINT8, BASE_HEX, NULL, 0x0,
725 static gint *ett[] = {
732 proto_tr = proto_register_protocol("Token-Ring", "Token-Ring", "tr");
733 proto_register_field_array(proto_tr, hf, array_length(hf));
734 proto_register_subtree_array(ett, array_length(ett));
736 /* Register configuration options */
737 tr_module = prefs_register_protocol(proto_tr, NULL);
738 prefs_register_bool_preference(tr_module, "fix_linux_botches",
739 "Attempt to compensate for Linux mangling of the link-layer header",
740 "Whether Linux mangling of the link-layer header should be checked for and worked around",
743 register_dissector("tr", dissect_tr, proto_tr);
744 tr_tap=register_tap("tr");
748 proto_reg_handoff_tr(void)
750 dissector_handle_t tr_handle;
753 * Get handles for the TR MAC and LLC dissectors.
755 trmac_handle = find_dissector("trmac");
756 llc_handle = find_dissector("llc");
757 data_handle = find_dissector("data");
759 tr_handle = find_dissector("tr");
760 dissector_add("wtap_encap", WTAP_ENCAP_TOKEN_RING, tr_handle);