summaryrefslogtreecommitdiff
path: root/print-eigrp.c
blob: aa113415f93cbb4959dee3852c696335a1515b39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
/*
 * Copyright (c) 1998-2004  Hannes Gredler <hannes@gredler.at>
 *      The TCPDUMP project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code
 * distributions retain the above copyright notice and this paragraph
 * in its entirety, and (2) distributions including binary code include
 * the above copyright notice and this paragraph in its entirety in
 * the documentation or other materials provided with the distribution.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 */

/* \summary: Enhanced Interior Gateway Routing Protocol (EIGRP) printer */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <netdissect-stdinc.h>

#include <string.h>

#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"

/*
 * packet format documented at
 * http://www.rhyshaden.com/eigrp.htm
 * RFC 7868
 */

struct eigrp_common_header {
    uint8_t version;
    uint8_t opcode;
    uint8_t checksum[2];
    uint8_t flags[4];
    uint8_t seq[4];
    uint8_t ack[4];
    uint8_t asn[4];
};

#define	EIGRP_VERSION                        2

#define	EIGRP_OPCODE_UPDATE                  1
#define	EIGRP_OPCODE_QUERY                   3
#define	EIGRP_OPCODE_REPLY                   4
#define	EIGRP_OPCODE_HELLO                   5
#define	EIGRP_OPCODE_IPXSAP                  6
#define	EIGRP_OPCODE_PROBE                   7

static const struct tok eigrp_opcode_values[] = {
    { EIGRP_OPCODE_UPDATE, "Update" },
    { EIGRP_OPCODE_QUERY, "Query" },
    { EIGRP_OPCODE_REPLY, "Reply" },
    { EIGRP_OPCODE_HELLO, "Hello" },
    { EIGRP_OPCODE_IPXSAP, "IPX SAP" },
    { EIGRP_OPCODE_PROBE, "Probe" },
    { 0, NULL}
};

static const struct tok eigrp_common_header_flag_values[] = {
    { 0x01, "Init" },
    { 0x02, "Conditionally Received" },
    { 0, NULL}
};

struct eigrp_tlv_header {
    uint8_t type[2];
    uint8_t length[2];
};

#define EIGRP_TLV_GENERAL_PARM   0x0001
#define EIGRP_TLV_AUTH           0x0002
#define EIGRP_TLV_SEQ            0x0003
#define EIGRP_TLV_SW_VERSION     0x0004
#define EIGRP_TLV_MCAST_SEQ      0x0005
#define EIGRP_TLV_IP_INT         0x0102
#define EIGRP_TLV_IP_EXT         0x0103
#define EIGRP_TLV_AT_INT         0x0202
#define EIGRP_TLV_AT_EXT         0x0203
#define EIGRP_TLV_AT_CABLE_SETUP 0x0204
#define EIGRP_TLV_IPX_INT        0x0302
#define EIGRP_TLV_IPX_EXT        0x0303

static const struct tok eigrp_tlv_values[] = {
    { EIGRP_TLV_GENERAL_PARM, "General Parameters"},
    { EIGRP_TLV_AUTH, "Authentication"},
    { EIGRP_TLV_SEQ, "Sequence"},
    { EIGRP_TLV_SW_VERSION, "Software Version"},
    { EIGRP_TLV_MCAST_SEQ, "Next Multicast Sequence"},
    { EIGRP_TLV_IP_INT, "IP Internal routes"},
    { EIGRP_TLV_IP_EXT, "IP External routes"},
    { EIGRP_TLV_AT_INT, "AppleTalk Internal routes"},
    { EIGRP_TLV_AT_EXT, "AppleTalk External routes"},
    { EIGRP_TLV_AT_CABLE_SETUP, "AppleTalk Cable setup"},
    { EIGRP_TLV_IPX_INT, "IPX Internal routes"},
    { EIGRP_TLV_IPX_EXT, "IPX External routes"},
    { 0, NULL}
};

struct eigrp_tlv_general_parm_t {
    uint8_t k1;
    uint8_t k2;
    uint8_t k3;
    uint8_t k4;
    uint8_t k5;
    uint8_t res;
    uint8_t holdtime[2];
};

struct eigrp_tlv_sw_version_t {
    uint8_t ios_major;
    uint8_t ios_minor;
    uint8_t eigrp_major;
    uint8_t eigrp_minor;
};

struct eigrp_tlv_ip_int_t {
    uint8_t nexthop[4];
    uint8_t delay[4];
    uint8_t bandwidth[4];
    uint8_t mtu[3];
    uint8_t hopcount;
    uint8_t reliability;
    uint8_t load;
    uint8_t reserved[2];
    uint8_t plen;
    uint8_t destination; /* variable length [1-4] bytes encoding */
};

struct eigrp_tlv_ip_ext_t {
    uint8_t nexthop[4];
    uint8_t origin_router[4];
    uint8_t origin_as[4];
    uint8_t tag[4];
    uint8_t metric[4];
    uint8_t reserved[2];
    uint8_t proto_id;
    uint8_t flags;
    uint8_t delay[4];
    uint8_t bandwidth[4];
    uint8_t mtu[3];
    uint8_t hopcount;
    uint8_t reliability;
    uint8_t load;
    uint8_t reserved2[2];
    uint8_t plen;
    uint8_t destination; /* variable length [1-4] bytes encoding */
};

struct eigrp_tlv_at_cable_setup_t {
    uint8_t cable_start[2];
    uint8_t cable_end[2];
    uint8_t router_id[4];
};

struct eigrp_tlv_at_int_t {
    uint8_t nexthop[4];
    uint8_t delay[4];
    uint8_t bandwidth[4];
    uint8_t mtu[3];
    uint8_t hopcount;
    uint8_t reliability;
    uint8_t load;
    uint8_t reserved[2];
    uint8_t cable_start[2];
    uint8_t cable_end[2];
};

struct eigrp_tlv_at_ext_t {
    uint8_t nexthop[4];
    uint8_t origin_router[4];
    uint8_t origin_as[4];
    uint8_t tag[4];
    uint8_t proto_id;
    uint8_t flags;
    uint8_t metric[2];
    uint8_t delay[4];
    uint8_t bandwidth[4];
    uint8_t mtu[3];
    uint8_t hopcount;
    uint8_t reliability;
    uint8_t load;
    uint8_t reserved2[2];
    uint8_t cable_start[2];
    uint8_t cable_end[2];
};

static const struct tok eigrp_ext_proto_id_values[] = {
    { 0x01, "IGRP" },
    { 0x02, "EIGRP" },
    { 0x03, "Static" },
    { 0x04, "RIP" },
    { 0x05, "Hello" },
    { 0x06, "OSPF" },
    { 0x07, "IS-IS" },
    { 0x08, "EGP" },
    { 0x09, "BGP" },
    { 0x0a, "IDRP" },
    { 0x0b, "Connected" },
    { 0, NULL}
};

void
eigrp_print(netdissect_options *ndo, register const u_char *pptr, register u_int len)
{
    const struct eigrp_common_header *eigrp_com_header;
    const struct eigrp_tlv_header *eigrp_tlv_header;
    const u_char *tptr,*tlv_tptr;
    u_int tlen,eigrp_tlv_len,eigrp_tlv_type,tlv_tlen, byte_length, bit_length;
    uint8_t prefix[4];

    union {
        const struct eigrp_tlv_general_parm_t *eigrp_tlv_general_parm;
        const struct eigrp_tlv_sw_version_t *eigrp_tlv_sw_version;
        const struct eigrp_tlv_ip_int_t *eigrp_tlv_ip_int;
        const struct eigrp_tlv_ip_ext_t *eigrp_tlv_ip_ext;
        const struct eigrp_tlv_at_cable_setup_t *eigrp_tlv_at_cable_setup;
        const struct eigrp_tlv_at_int_t *eigrp_tlv_at_int;
        const struct eigrp_tlv_at_ext_t *eigrp_tlv_at_ext;
    } tlv_ptr;

    tptr=pptr;
    eigrp_com_header = (const struct eigrp_common_header *)pptr;
    ND_TCHECK(*eigrp_com_header);

    /*
     * Sanity checking of the header.
     */
    if (eigrp_com_header->version != EIGRP_VERSION) {
	ND_PRINT((ndo, "EIGRP version %u packet not supported",eigrp_com_header->version));
	return;
    }

    /* in non-verbose mode just lets print the basic Message Type*/
    if (ndo->ndo_vflag < 1) {
        ND_PRINT((ndo, "EIGRP %s, length: %u",
               tok2str(eigrp_opcode_values, "unknown (%u)",eigrp_com_header->opcode),
               len));
        return;
    }

    /* ok they seem to want to know everything - lets fully decode it */

    if (len < sizeof(struct eigrp_common_header)) {
        ND_PRINT((ndo, "EIGRP %s, length: %u (too short, < %u)",
               tok2str(eigrp_opcode_values, "unknown (%u)",eigrp_com_header->opcode),
               len, (u_int) sizeof(struct eigrp_common_header)));
        return;
    }
    tlen=len-sizeof(struct eigrp_common_header);

    /* FIXME print other header info */
    ND_PRINT((ndo, "\n\tEIGRP v%u, opcode: %s (%u), chksum: 0x%04x, Flags: [%s]\n\tseq: 0x%08x, ack: 0x%08x, AS: %u, length: %u",
           eigrp_com_header->version,
           tok2str(eigrp_opcode_values, "unknown, type: %u",eigrp_com_header->opcode),
           eigrp_com_header->opcode,
           EXTRACT_16BITS(&eigrp_com_header->checksum),
           tok2str(eigrp_common_header_flag_values,
                   "none",
                   EXTRACT_32BITS(&eigrp_com_header->flags)),
           EXTRACT_32BITS(&eigrp_com_header->seq),
           EXTRACT_32BITS(&eigrp_com_header->ack),
           EXTRACT_32BITS(&eigrp_com_header->asn),
           tlen));

    tptr+=sizeof(const struct eigrp_common_header);

    while(tlen>0) {
        /* did we capture enough for fully decoding the object header ? */
        ND_TCHECK2(*tptr, sizeof(struct eigrp_tlv_header));

        eigrp_tlv_header = (const struct eigrp_tlv_header *)tptr;
        eigrp_tlv_len=EXTRACT_16BITS(&eigrp_tlv_header->length);
        eigrp_tlv_type=EXTRACT_16BITS(&eigrp_tlv_header->type);


        if (eigrp_tlv_len < sizeof(struct eigrp_tlv_header) ||
            eigrp_tlv_len > tlen) {
            print_unknown_data(ndo,tptr+sizeof(struct eigrp_tlv_header),"\n\t    ",tlen);
            return;
        }

        ND_PRINT((ndo, "\n\t  %s TLV (0x%04x), length: %u",
               tok2str(eigrp_tlv_values,
                       "Unknown",
                       eigrp_tlv_type),
               eigrp_tlv_type,
               eigrp_tlv_len));

        if (eigrp_tlv_len < sizeof(struct eigrp_tlv_header)) {
                ND_PRINT((ndo, " (too short, < %u)",
                        (u_int) sizeof(struct eigrp_tlv_header)));
                break;
        }
        tlv_tptr=tptr+sizeof(struct eigrp_tlv_header);
        tlv_tlen=eigrp_tlv_len-sizeof(struct eigrp_tlv_header);

        /* did we capture enough for fully decoding the object ? */
        ND_TCHECK2(*tptr, eigrp_tlv_len);

        switch(eigrp_tlv_type) {

        case EIGRP_TLV_GENERAL_PARM:
            tlv_ptr.eigrp_tlv_general_parm = (const struct eigrp_tlv_general_parm_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_general_parm)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_general_parm))));
                break;
            }

            ND_PRINT((ndo, "\n\t    holdtime: %us, k1 %u, k2 %u, k3 %u, k4 %u, k5 %u",
                   EXTRACT_16BITS(tlv_ptr.eigrp_tlv_general_parm->holdtime),
                   tlv_ptr.eigrp_tlv_general_parm->k1,
                   tlv_ptr.eigrp_tlv_general_parm->k2,
                   tlv_ptr.eigrp_tlv_general_parm->k3,
                   tlv_ptr.eigrp_tlv_general_parm->k4,
                   tlv_ptr.eigrp_tlv_general_parm->k5));
            break;

        case EIGRP_TLV_SW_VERSION:
            tlv_ptr.eigrp_tlv_sw_version = (const struct eigrp_tlv_sw_version_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_sw_version)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_sw_version))));
                break;
            }

            ND_PRINT((ndo, "\n\t    IOS version: %u.%u, EIGRP version %u.%u",
                   tlv_ptr.eigrp_tlv_sw_version->ios_major,
                   tlv_ptr.eigrp_tlv_sw_version->ios_minor,
                   tlv_ptr.eigrp_tlv_sw_version->eigrp_major,
                   tlv_ptr.eigrp_tlv_sw_version->eigrp_minor));
            break;

        case EIGRP_TLV_IP_INT:
            tlv_ptr.eigrp_tlv_ip_int = (const struct eigrp_tlv_ip_int_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_ip_int)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_ip_int))));
                break;
            }

            bit_length = tlv_ptr.eigrp_tlv_ip_int->plen;
            if (bit_length > 32) {
                ND_PRINT((ndo, "\n\t    illegal prefix length %u",bit_length));
                break;
            }
            byte_length = (bit_length + 7) / 8; /* variable length encoding */
            memset(prefix, 0, 4);
            memcpy(prefix,&tlv_ptr.eigrp_tlv_ip_int->destination,byte_length);

            ND_PRINT((ndo, "\n\t    IPv4 prefix: %15s/%u, nexthop: ",
                   ipaddr_string(ndo, prefix),
                   bit_length));
            if (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->nexthop) == 0)
                ND_PRINT((ndo, "self"));
            else
                ND_PRINT((ndo, "%s",ipaddr_string(ndo, &tlv_ptr.eigrp_tlv_ip_int->nexthop)));

            ND_PRINT((ndo, "\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->delay)/100),
                   EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_int->bandwidth),
                   EXTRACT_24BITS(&tlv_ptr.eigrp_tlv_ip_int->mtu),
                   tlv_ptr.eigrp_tlv_ip_int->hopcount,
                   tlv_ptr.eigrp_tlv_ip_int->reliability,
                   tlv_ptr.eigrp_tlv_ip_int->load));
            break;

        case EIGRP_TLV_IP_EXT:
            tlv_ptr.eigrp_tlv_ip_ext = (const struct eigrp_tlv_ip_ext_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_ip_ext)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_ip_ext))));
                break;
            }

            bit_length = tlv_ptr.eigrp_tlv_ip_ext->plen;
            if (bit_length > 32) {
                ND_PRINT((ndo, "\n\t    illegal prefix length %u",bit_length));
                break;
            }
            byte_length = (bit_length + 7) / 8; /* variable length encoding */
            memset(prefix, 0, 4);
            memcpy(prefix,&tlv_ptr.eigrp_tlv_ip_ext->destination,byte_length);

            ND_PRINT((ndo, "\n\t    IPv4 prefix: %15s/%u, nexthop: ",
                   ipaddr_string(ndo, prefix),
                   bit_length));
            if (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_ext->nexthop) == 0)
                ND_PRINT((ndo, "self"));
            else
                ND_PRINT((ndo, "%s",ipaddr_string(ndo, &tlv_ptr.eigrp_tlv_ip_ext->nexthop)));

            ND_PRINT((ndo, "\n\t      origin-router %s, origin-as %u, origin-proto %s, flags [0x%02x], tag 0x%08x, metric %u",
                   ipaddr_string(ndo, tlv_ptr.eigrp_tlv_ip_ext->origin_router),
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_ip_ext->origin_as),
                   tok2str(eigrp_ext_proto_id_values,"unknown",tlv_ptr.eigrp_tlv_ip_ext->proto_id),
                   tlv_ptr.eigrp_tlv_ip_ext->flags,
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_ip_ext->tag),
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_ip_ext->metric)));

            ND_PRINT((ndo, "\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_ext->delay)/100),
                   EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_ip_ext->bandwidth),
                   EXTRACT_24BITS(&tlv_ptr.eigrp_tlv_ip_ext->mtu),
                   tlv_ptr.eigrp_tlv_ip_ext->hopcount,
                   tlv_ptr.eigrp_tlv_ip_ext->reliability,
                   tlv_ptr.eigrp_tlv_ip_ext->load));
            break;

        case EIGRP_TLV_AT_CABLE_SETUP:
            tlv_ptr.eigrp_tlv_at_cable_setup = (const struct eigrp_tlv_at_cable_setup_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_at_cable_setup)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_cable_setup))));
                break;
            }

            ND_PRINT((ndo, "\n\t    Cable-range: %u-%u, Router-ID %u",
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_cable_setup->cable_start),
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_cable_setup->cable_end),
                   EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_cable_setup->router_id)));
            break;

        case EIGRP_TLV_AT_INT:
            tlv_ptr.eigrp_tlv_at_int = (const struct eigrp_tlv_at_int_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_at_int)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_int))));
                break;
            }

            ND_PRINT((ndo, "\n\t     Cable-Range: %u-%u, nexthop: ",
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_int->cable_start),
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_int->cable_end)));

            if (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_int->nexthop) == 0)
                ND_PRINT((ndo, "self"));
            else
                ND_PRINT((ndo, "%u.%u",
                       EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_int->nexthop),
                       EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_int->nexthop[2])));

            ND_PRINT((ndo, "\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_int->delay)/100),
                   EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_int->bandwidth),
                   EXTRACT_24BITS(&tlv_ptr.eigrp_tlv_at_int->mtu),
                   tlv_ptr.eigrp_tlv_at_int->hopcount,
                   tlv_ptr.eigrp_tlv_at_int->reliability,
                   tlv_ptr.eigrp_tlv_at_int->load));
            break;

        case EIGRP_TLV_AT_EXT:
            tlv_ptr.eigrp_tlv_at_ext = (const struct eigrp_tlv_at_ext_t *)tlv_tptr;
            if (tlv_tlen < sizeof(*tlv_ptr.eigrp_tlv_at_ext)) {
                ND_PRINT((ndo, " (too short, < %u)",
                    (u_int) (sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_ext))));
                break;
            }

            ND_PRINT((ndo, "\n\t     Cable-Range: %u-%u, nexthop: ",
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_ext->cable_start),
                   EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_ext->cable_end)));

            if (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_ext->nexthop) == 0)
                ND_PRINT((ndo, "self"));
            else
                ND_PRINT((ndo, "%u.%u",
                       EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_ext->nexthop),
                       EXTRACT_16BITS(&tlv_ptr.eigrp_tlv_at_ext->nexthop[2])));

            ND_PRINT((ndo, "\n\t      origin-router %u, origin-as %u, origin-proto %s, flags [0x%02x], tag 0x%08x, metric %u",
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_at_ext->origin_router),
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_at_ext->origin_as),
                   tok2str(eigrp_ext_proto_id_values,"unknown",tlv_ptr.eigrp_tlv_at_ext->proto_id),
                   tlv_ptr.eigrp_tlv_at_ext->flags,
                   EXTRACT_32BITS(tlv_ptr.eigrp_tlv_at_ext->tag),
                   EXTRACT_16BITS(tlv_ptr.eigrp_tlv_at_ext->metric)));

            ND_PRINT((ndo, "\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_ext->delay)/100),
                   EXTRACT_32BITS(&tlv_ptr.eigrp_tlv_at_ext->bandwidth),
                   EXTRACT_24BITS(&tlv_ptr.eigrp_tlv_at_ext->mtu),
                   tlv_ptr.eigrp_tlv_at_ext->hopcount,
                   tlv_ptr.eigrp_tlv_at_ext->reliability,
                   tlv_ptr.eigrp_tlv_at_ext->load));
            break;

            /*
             * FIXME those are the defined TLVs that lack a decoder
             * you are welcome to contribute code ;-)
             */

        case EIGRP_TLV_AUTH:
        case EIGRP_TLV_SEQ:
        case EIGRP_TLV_MCAST_SEQ:
        case EIGRP_TLV_IPX_INT:
        case EIGRP_TLV_IPX_EXT:

        default:
            if (ndo->ndo_vflag <= 1)
                print_unknown_data(ndo,tlv_tptr,"\n\t    ",tlv_tlen);
            break;
        }
        /* do we want to see an additionally hexdump ? */
        if (ndo->ndo_vflag > 1)
            print_unknown_data(ndo,tptr+sizeof(struct eigrp_tlv_header),"\n\t    ",
                               eigrp_tlv_len-sizeof(struct eigrp_tlv_header));

        tptr+=eigrp_tlv_len;
        tlen-=eigrp_tlv_len;
    }
    return;
trunc:
    ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
}