/*
 * 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 */

/*
 * specification:
 *
 * https://web.archive.org/web/20190722221712/https://www.rhyshaden.com/eigrp.htm
 * RFC 7868
 */

#include <config.h>

#include "netdissect-stdinc.h"

#include <string.h>

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


struct eigrp_common_header {
    nd_uint8_t  version;
    nd_uint8_t  opcode;
    nd_uint16_t checksum;
    nd_uint32_t flags;
    nd_uint32_t seq;
    nd_uint32_t ack;
    nd_uint16_t vrid;
    nd_uint16_t asn;
};

#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" },
    { 0x04, "Restart" },
    { 0x08, "End-of-Table" },
    { 0, NULL}
};

struct eigrp_tlv_header {
    nd_uint16_t type;
    nd_uint16_t length;
};

#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 {
    nd_uint8_t  k1;
    nd_uint8_t  k2;
    nd_uint8_t  k3;
    nd_uint8_t  k4;
    nd_uint8_t  k5;
    nd_uint8_t  res;
    nd_uint16_t holdtime;
};

struct eigrp_tlv_sw_version_t {
    nd_uint8_t ios_major;
    nd_uint8_t ios_minor;
    nd_uint8_t eigrp_major;
    nd_uint8_t eigrp_minor;
};

struct eigrp_tlv_ip_int_t {
    nd_ipv4     nexthop;
    nd_uint32_t delay;
    nd_uint32_t bandwidth;
    nd_uint24_t mtu;
    nd_uint8_t  hopcount;
    nd_uint8_t  reliability;
    nd_uint8_t  load;
    nd_byte     reserved[2];
    nd_uint8_t  plen;
    nd_uint8_t  destination; /* variable length [1-4] bytes encoding */
};

struct eigrp_tlv_ip_ext_t {
    nd_ipv4     nexthop;
    nd_ipv4     origin_router;
    nd_uint32_t origin_as;
    nd_uint32_t tag;
    nd_uint32_t metric;
    nd_byte     reserved[2];
    nd_uint8_t  proto_id;
    nd_uint8_t  flags;
    nd_uint32_t delay;
    nd_uint32_t bandwidth;
    nd_uint24_t mtu;
    nd_uint8_t  hopcount;
    nd_uint8_t  reliability;
    nd_uint8_t  load;
    nd_byte     reserved2[2];
    nd_uint8_t  plen;
    nd_uint8_t  destination; /* variable length [1-4] bytes encoding */
};

struct eigrp_tlv_at_cable_setup_t {
    nd_uint16_t cable_start;
    nd_uint16_t cable_end;
    nd_uint32_t router_id;
};

struct eigrp_tlv_at_int_t {
    nd_byte     nexthop[4];
    nd_uint32_t delay;
    nd_uint32_t bandwidth;
    nd_uint24_t mtu;
    nd_uint8_t  hopcount;
    nd_uint8_t  reliability;
    nd_uint8_t  load;
    nd_byte     reserved[2];
    nd_uint16_t cable_start;
    nd_uint16_t cable_end;
};

struct eigrp_tlv_at_ext_t {
    nd_byte     nexthop[4];
    nd_uint32_t origin_router;
    nd_uint32_t origin_as;
    nd_uint32_t tag;
    nd_uint8_t  proto_id;
    nd_uint8_t  flags;
    nd_uint16_t metric;
    nd_uint32_t delay;
    nd_uint32_t bandwidth;
    nd_uint24_t mtu;
    nd_uint8_t  hopcount;
    nd_uint8_t  reliability;
    nd_uint8_t  load;
    nd_byte     reserved2[2];
    nd_uint16_t cable_start;
    nd_uint16_t cable_end;
};

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, const u_char *pptr, 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;

    ndo->ndo_protocol = "eigrp";
    tptr=pptr;
    eigrp_com_header = (const struct eigrp_common_header *)pptr;
    ND_TCHECK_SIZE(eigrp_com_header);

    /*
     * Sanity checking of the header.
     */
    if (GET_U_1(eigrp_com_header->version) != EIGRP_VERSION) {
        ND_PRINT("EIGRP version %u packet not supported",
                 GET_U_1(eigrp_com_header->version));
        return;
    }

    /* in non-verbose mode just lets print the basic Message Type*/
    if (ndo->ndo_vflag < 1) {
        ND_PRINT("EIGRP %s, length: %u",
               tok2str(eigrp_opcode_values, "unknown (%u)",GET_U_1(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("EIGRP %s, length: %u (too short, < %zu)",
               tok2str(eigrp_opcode_values, "unknown (%u)",GET_U_1(eigrp_com_header->opcode)),
               len, sizeof(struct eigrp_common_header));
        return;
    }
    tlen=len-sizeof(struct eigrp_common_header);

    ND_PRINT("\n\tEIGRP v%u, opcode: %s (%u), chksum: 0x%04x, Flags: [%s]"
             "\n\tseq: 0x%08x, ack: 0x%08x, VRID: %u, AS: %u, length: %u",
           GET_U_1(eigrp_com_header->version),
           tok2str(eigrp_opcode_values, "unknown, type: %u",GET_U_1(eigrp_com_header->opcode)),
           GET_U_1(eigrp_com_header->opcode),
           GET_BE_U_2(eigrp_com_header->checksum),
           bittok2str(eigrp_common_header_flag_values,
                   "none",
                   GET_BE_U_4(eigrp_com_header->flags)),
           GET_BE_U_4(eigrp_com_header->seq),
           GET_BE_U_4(eigrp_com_header->ack),
           GET_BE_U_2(eigrp_com_header->vrid),
           GET_BE_U_2(eigrp_com_header->asn),
           tlen);

    tptr+=sizeof(struct eigrp_common_header);

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

        eigrp_tlv_header = (const struct eigrp_tlv_header *)tptr;
        eigrp_tlv_len=GET_BE_U_2(eigrp_tlv_header->length);
        eigrp_tlv_type=GET_BE_U_2(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("\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(" (too short, < %zu)",
                         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_TCHECK_LEN(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(" (too short, < %zu)",
			 sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_general_parm));
                break;
            }

            ND_PRINT("\n\t    holdtime: %us, k1 %u, k2 %u, k3 %u, k4 %u, k5 %u",
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_general_parm->holdtime),
                   GET_U_1(tlv_ptr.eigrp_tlv_general_parm->k1),
                   GET_U_1(tlv_ptr.eigrp_tlv_general_parm->k2),
                   GET_U_1(tlv_ptr.eigrp_tlv_general_parm->k3),
                   GET_U_1(tlv_ptr.eigrp_tlv_general_parm->k4),
                   GET_U_1(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_sw_version));
                break;
            }

            ND_PRINT("\n\t    IOS version: %u.%u, EIGRP version %u.%u",
                   GET_U_1(tlv_ptr.eigrp_tlv_sw_version->ios_major),
                   GET_U_1(tlv_ptr.eigrp_tlv_sw_version->ios_minor),
                   GET_U_1(tlv_ptr.eigrp_tlv_sw_version->eigrp_major),
                   GET_U_1(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_ip_int));
                break;
            }

            bit_length = GET_U_1(tlv_ptr.eigrp_tlv_ip_int->plen);
            if (bit_length > 32) {
                ND_PRINT("\n\t    illegal prefix length %u",bit_length);
                break;
            }
            byte_length = (bit_length + 7) / 8; /* variable length encoding */
            memset(prefix, 0, 4);
            GET_CPY_BYTES(prefix, tlv_ptr.eigrp_tlv_ip_int->destination, byte_length);

            ND_PRINT("\n\t    IPv4 prefix: %15s/%u, nexthop: ",
                   ipaddr_string(ndo, prefix),	/* local buffer, not packet data; don't use GET_IPADDR_STRING() */
                   bit_length);
            if (GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_int->nexthop) == 0)
                ND_PRINT("self");
            else
                ND_PRINT("%s",
                         GET_IPADDR_STRING(tlv_ptr.eigrp_tlv_ip_int->nexthop));

            ND_PRINT("\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_int->delay)/100),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_int->bandwidth),
                   GET_BE_U_3(tlv_ptr.eigrp_tlv_ip_int->mtu),
                   GET_U_1(tlv_ptr.eigrp_tlv_ip_int->hopcount),
                   GET_U_1(tlv_ptr.eigrp_tlv_ip_int->reliability),
                   GET_U_1(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_ip_ext));
                break;
            }

            bit_length = GET_U_1(tlv_ptr.eigrp_tlv_ip_ext->plen);
            if (bit_length > 32) {
                ND_PRINT("\n\t    illegal prefix length %u",bit_length);
                break;
            }
            byte_length = (bit_length + 7) / 8; /* variable length encoding */
            memset(prefix, 0, 4);
            GET_CPY_BYTES(prefix, tlv_ptr.eigrp_tlv_ip_ext->destination, byte_length);

            ND_PRINT("\n\t    IPv4 prefix: %15s/%u, nexthop: ",
                   ipaddr_string(ndo, prefix),	/* local buffer, not packet data; don't use GET_IPADDR_STRING() */
                   bit_length);
            if (GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->nexthop) == 0)
                ND_PRINT("self");
            else
                ND_PRINT("%s",
                         GET_IPADDR_STRING(tlv_ptr.eigrp_tlv_ip_ext->nexthop));

            ND_PRINT("\n\t      origin-router %s, origin-as %u, origin-proto %s, flags [0x%02x], tag 0x%08x, metric %u",
                   GET_IPADDR_STRING(tlv_ptr.eigrp_tlv_ip_ext->origin_router),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->origin_as),
                   tok2str(eigrp_ext_proto_id_values,"unknown",GET_U_1(tlv_ptr.eigrp_tlv_ip_ext->proto_id)),
                   GET_U_1(tlv_ptr.eigrp_tlv_ip_ext->flags),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->tag),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->metric));

            ND_PRINT("\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->delay)/100),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_ip_ext->bandwidth),
                   GET_BE_U_3(tlv_ptr.eigrp_tlv_ip_ext->mtu),
                   GET_U_1(tlv_ptr.eigrp_tlv_ip_ext->hopcount),
                   GET_U_1(tlv_ptr.eigrp_tlv_ip_ext->reliability),
                   GET_U_1(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_cable_setup));
                break;
            }

            ND_PRINT("\n\t    Cable-range: %u-%u, Router-ID %u",
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_cable_setup->cable_start),
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_cable_setup->cable_end),
                   GET_BE_U_4(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_int));
                break;
            }

            ND_PRINT("\n\t     Cable-Range: %u-%u, nexthop: ",
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_int->cable_start),
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_int->cable_end));

            if (GET_BE_U_4(tlv_ptr.eigrp_tlv_at_int->nexthop) == 0)
                ND_PRINT("self");
            else
                ND_PRINT("%u.%u",
                       GET_BE_U_2(&tlv_ptr.eigrp_tlv_at_int->nexthop[0]),
                       GET_BE_U_2(&tlv_ptr.eigrp_tlv_at_int->nexthop[2]));

            ND_PRINT("\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (GET_BE_U_4(tlv_ptr.eigrp_tlv_at_int->delay)/100),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_at_int->bandwidth),
                   GET_BE_U_3(tlv_ptr.eigrp_tlv_at_int->mtu),
                   GET_U_1(tlv_ptr.eigrp_tlv_at_int->hopcount),
                   GET_U_1(tlv_ptr.eigrp_tlv_at_int->reliability),
                   GET_U_1(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(" (too short, < %zu)",
                         sizeof(struct eigrp_tlv_header) + sizeof(*tlv_ptr.eigrp_tlv_at_ext));
                break;
            }

            ND_PRINT("\n\t     Cable-Range: %u-%u, nexthop: ",
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_ext->cable_start),
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_ext->cable_end));

            if (GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->nexthop) == 0)
                ND_PRINT("self");
            else
                ND_PRINT("%u.%u",
                       GET_BE_U_2(&tlv_ptr.eigrp_tlv_at_ext->nexthop[0]),
                       GET_BE_U_2(&tlv_ptr.eigrp_tlv_at_ext->nexthop[2]));

            ND_PRINT("\n\t      origin-router %u, origin-as %u, origin-proto %s, flags [0x%02x], tag 0x%08x, metric %u",
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->origin_router),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->origin_as),
                   tok2str(eigrp_ext_proto_id_values,"unknown",GET_U_1(tlv_ptr.eigrp_tlv_at_ext->proto_id)),
                   GET_U_1(tlv_ptr.eigrp_tlv_at_ext->flags),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->tag),
                   GET_BE_U_2(tlv_ptr.eigrp_tlv_at_ext->metric));

            ND_PRINT("\n\t      delay %u ms, bandwidth %u Kbps, mtu %u, hop %u, reliability %u, load %u",
                   (GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->delay)/100),
                   GET_BE_U_4(tlv_ptr.eigrp_tlv_at_ext->bandwidth),
                   GET_BE_U_3(tlv_ptr.eigrp_tlv_at_ext->mtu),
                   GET_U_1(tlv_ptr.eigrp_tlv_at_ext->hopcount),
                   GET_U_1(tlv_ptr.eigrp_tlv_at_ext->reliability),
                   GET_U_1(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_trunc(ndo);
}