/* packet-isis-hello.c

 * Routines for decoding isis hello packets and their CLVs

 *

 * Stuart Stanley <stuarts@mxmail.net>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/expert.h>

#include <epan/tfs.h>

#include <wsutil/array.h>

#include "packet-osi.h"

#include "packet-isis.h"

#include "packet-isis-clv.h"

/*

 * Declarations for L1/L2 hello base header.

 */

#define ISIS_HELLO_CTYPE_MASK           0x03

#define ISIS_HELLO_CT_RESERVED_MASK     0xfc

#define ISIS_HELLO_PRIORITY_MASK        0x7f

#define ISIS_HELLO_P_RESERVED_MASK      0x80

#define ISIS_HELLO_TYPE_RESERVED        0

#define ISIS_HELLO_TYPE_LEVEL_1         1

#define ISIS_HELLO_TYPE_LEVEL_2         2

#define ISIS_HELLO_TYPE_LEVEL_12        3

/*

 * misc. bittest macros

 */

#define ISIS_RESTART_RR                 0x01

#define ISIS_RESTART_RA                 0x02

#define ISIS_RESTART_SA                 0x04

#define ISIS_MASK_RESTART_RR(x)            ((x)&ISIS_RESTART_RR)

#define ISIS_MASK_RESTART_RA(x)            ((x)&ISIS_RESTART_RA)

#define ISIS_MASK_RESTART_SA(x)            ((x)&ISIS_RESTART_SA)

void proto_register_isis_hello(void);

void proto_reg_handoff_isis_hello(void);

static int proto_isis_hello;

/* hello packets */

static int hf_isis_hello_circuit;

static int hf_isis_hello_circuit_reserved;

static int hf_isis_hello_source_id;

static int hf_isis_hello_holding_timer;

static int hf_isis_hello_pdu_length;

static int hf_isis_hello_priority;

static int hf_isis_hello_priority_reserved;

static int hf_isis_hello_lan_id;

static int hf_isis_hello_clv_type;

static int hf_isis_hello_clv_length;

static int hf_isis_hello_local_circuit_id;

static int hf_isis_hello_clv_ipv4_int_addr;

static int hf_isis_hello_clv_ipv6_int_addr;

/* static int hf_isis_hello_clv_ptp_adj; */

static int hf_isis_hello_clv_mt;

static int hf_isis_hello_clv_restart_flags;

static int hf_isis_hello_clv_restart_flags_rr;

static int hf_isis_hello_clv_restart_flags_ra;

static int hf_isis_hello_clv_restart_flags_sa;

static int hf_isis_hello_clv_restart_remain_time;

static int hf_isis_hello_clv_restart_neighbor;

/* Generated from convert_proto_tree_add_text.pl */

static int hf_isis_hello_extended_local_circuit_id;

static int hf_isis_hello_adjacency_state;

static int hf_isis_hello_neighbor_systemid;

static int hf_isis_hello_digest;

static int hf_isis_hello_digest_v;

static int hf_isis_hello_digest_a;

static int hf_isis_hello_digest_d;

static int hf_isis_hello_ect;

static int hf_isis_hello_bvid;

static int hf_isis_hello_bvid_u;

static int hf_isis_hello_bvid_m;

static int hf_isis_hello_area_address;

static int hf_isis_hello_instance_identifier;

static int hf_isis_hello_supported_itid;

static int hf_isis_hello_clv_nlpid_nlpid;

static int hf_isis_hello_clv_ip_authentication;

static int hf_isis_hello_authentication;

static int hf_isis_hello_aux_mcid;

static int hf_isis_hello_mcid;

static int hf_isis_hello_is_neighbor;

static int hf_isis_hello_mtid;

static int hf_isis_hello_checksum;

static int hf_isis_hello_checksum_status;

static int hf_isis_hello_trill_neighbor_sf;

static int hf_isis_hello_trill_neighbor_lf;

static int hf_isis_hello_trill_neighbor_ff;

static int hf_isis_hello_trill_neighbor_of;

static int hf_isis_hello_trill_neighbor_size;

static int hf_isis_hello_trill_neighbor_reserved;

static int hf_isis_hello_trill_neighbor_mtu;

static int hf_isis_hello_trill_neighbor_snpa;

static int hf_isis_hello_reverse_metric_flags;

static int hf_isis_hello_reverse_metric_flag_reserved;

static int hf_isis_hello_reverse_metric_flag_u;

static int hf_isis_hello_reverse_metric_flag_w;

static int hf_isis_hello_reverse_metric_metric;

static int hf_isis_hello_reverse_metric_sub_length;

static int hf_isis_hello_reverse_metric_sub_data;

static int hf_isis_hello_bfd_enabled_nlpid;

static int hf_isis_hello_neighbor_extended_local_circuit_id;

static int hf_isis_hello_vlan_flags_port_id;

static int hf_isis_hello_vlan_flags_nickname;

static int hf_isis_hello_vlan_flags_af;

static int hf_isis_hello_vlan_flags_ac;

static int hf_isis_hello_vlan_flags_vm;

static int hf_isis_hello_vlan_flags_by;

static int hf_isis_hello_vlan_flags_outer_vlan;

static int hf_isis_hello_vlan_flags_tr;

static int hf_isis_hello_vlan_flags_reserved;

static int hf_isis_hello_vlan_flags_designated_vlan;

static int hf_isis_hello_enabled_vlans;

static int hf_isis_hello_appointed_vlans;

static int hf_isis_hello_af_nickname;

static int hf_isis_hello_af_start_vlan;

static int hf_isis_hello_af_end_vlan;

static int hf_isis_hello_trill_version;

static int hf_isis_hello_trill_hello_reduction;

static int hf_isis_hello_trill_unassigned_1;

static int hf_isis_hello_trill_hop_by_hop_flags;

static int hf_isis_hello_trill_unassigned_2;

static int hf_isis_hello_clv_ipv6_glb_int_addr;

static int ett_isis_hello;

static int ett_isis_hello_clv_area_addr;

static int ett_isis_hello_clv_instance_identifier;

static int ett_isis_hello_clv_is_neighbors;

static int ett_isis_hello_clv_padding;

static int ett_isis_hello_clv_unknown;

static int ett_isis_hello_clv_nlpid;

static int ett_isis_hello_clv_nlpid_nlpid;

static int ett_isis_hello_clv_authentication;

static int ett_isis_hello_clv_ip_authentication;

static int ett_isis_hello_clv_ipv4_int_addr;

static int ett_isis_hello_clv_ipv6_int_addr;

static int ett_isis_hello_clv_ptp_adj;

static int ett_isis_hello_clv_mt;

static int ett_isis_hello_clv_restart;

static int ett_isis_hello_clv_restart_flags;

static int ett_isis_hello_clv_mt_port_cap;

static int ett_isis_hello_clv_mt_port_cap_spb_mcid;

static int ett_isis_hello_clv_mt_port_cap_spb_digest;

static int ett_isis_hello_clv_mt_port_cap_spb_bvid_tuples;

static int ett_isis_hello_clv_mt_port_cap_vlan_flags;

static int ett_isis_hello_clv_mt_port_cap_enabled_vlans;

static int ett_isis_hello_clv_mt_port_cap_appointedfwrdrs;

static int ett_isis_hello_clv_mt_port_cap_port_trill_ver;

static int ett_isis_hello_clv_mt_port_cap_vlans_appointed;

static int ett_isis_hello_clv_trill_neighbor;

static int ett_isis_hello_clv_checksum;

static int ett_isis_hello_clv_reverse_metric;

static int ett_isis_hello_clv_bfd_enabled;

static int ett_isis_hello_clv_ipv6_glb_int_addr;

static int ett_isis_hello_reverse_metric_flags;

static expert_field ei_isis_hello_short_pdu;

static expert_field ei_isis_hello_long_pdu;

static expert_field ei_isis_hello_bad_checksum;

static expert_field ei_isis_hello_authentication;

static expert_field ei_isis_hello_subtlv;

static expert_field ei_isis_hello_short_clv;

static expert_field ei_isis_hello_clv_mt;

static expert_field ei_isis_hello_clv_unknown;

static const value_string isis_hello_circuit_type_vals[] = {

    { ISIS_HELLO_TYPE_RESERVED,    "Reserved 0 (discard PDU)"},

    { ISIS_HELLO_TYPE_LEVEL_1,    "Level 1 only"},

    { ISIS_HELLO_TYPE_LEVEL_2,    "Level 2 only"},

    { ISIS_HELLO_TYPE_LEVEL_12,    "Level 1 and 2"},

    { 0,        NULL} };

extern const range_string mtid_strings[];

static void

dissect_hello_mt_port_cap_spb_mcid_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    const int MCID_LEN = 51;

    const int SUBLEN   = 2 * MCID_LEN;

    proto_tree *subtree;

    if (sublen != SUBLEN) {

        proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                                     "Short SPB MCID TLV (%d vs %d)", sublen, SUBLEN);

        return;

    }

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_spb_mcid, NULL,

                                "SPB MCID: Type: 0x%02x, Length: %d", subtype, sublen);

    /* MCID: */

    proto_tree_add_item(subtree, hf_isis_hello_mcid, tvb, offset, MCID_LEN, ENC_NA);

    offset += MCID_LEN;

    /* Aux MCID: */

    proto_tree_add_item(subtree, hf_isis_hello_aux_mcid, tvb, offset, MCID_LEN, ENC_NA);

    /* offset += MCID_LEN; */

}

static void

dissect_hello_mt_port_cap_spb_digest_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    const int DIGEST_LEN = 32;

    const int SUBLEN     = 1 + DIGEST_LEN;

    if (sublen != SUBLEN) {

        proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                              "Short SPB Digest TLV (%d vs %d)", sublen, SUBLEN);

        return;

    }

    else {

        proto_tree *subtree;

        subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_spb_digest, NULL,

                                  "SPB Digest: Type: 0x%02x, Length: %d", subtype, sublen);

        proto_tree_add_item( subtree, hf_isis_hello_digest_v, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item( subtree, hf_isis_hello_digest_a, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item( subtree, hf_isis_hello_digest_d, tvb, offset, 1, ENC_BIG_ENDIAN);

        ++offset;

        /* Digest: */

        proto_tree_add_item(subtree, hf_isis_hello_digest, tvb, offset, DIGEST_LEN, ENC_NA);

        /* offset += DIGEST_LEN; */

    }

}

static void

dissect_hello_mt_port_cap_spb_bvid_tuples_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    int subofs = offset;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_spb_bvid_tuples, NULL,

                              "SPB Base Vlan Identifiers: Type: 0x%02x, Length: %d", subtype, sublen);

    while (sublen > 0) {

        if (sublen < 6) {

            proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                                  "Short SPB BVID header entry (%d vs %d)", sublen, 6);

            return;

        }

        else {

            proto_tree_add_item( subtree, hf_isis_hello_ect, tvb, subofs, 4, ENC_NA);

            proto_tree_add_item( subtree, hf_isis_hello_bvid, tvb, subofs+4, 2, ENC_BIG_ENDIAN);

            proto_tree_add_item( subtree, hf_isis_hello_bvid_u, tvb, subofs+4, 2, ENC_BIG_ENDIAN);

            proto_tree_add_item( subtree, hf_isis_hello_bvid_m, tvb, subofs+4, 2, ENC_BIG_ENDIAN);

        }

        sublen -= 6;

        subofs += 6;

    }

}

static void

dissect_hello_mt_port_cap_vlan_flags_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_vlan_flags, NULL,

                                "Special VLANs and Flags (t=%u, l=%u)", subtype, sublen);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_port_id, tvb, offset, 2, ENC_BIG_ENDIAN);

    offset += 2;

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_nickname, tvb, offset, 2, ENC_BIG_ENDIAN);

    offset += 2;

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_af, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_ac, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_vm, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_by, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_outer_vlan, tvb, offset, 2, ENC_BIG_ENDIAN);

    offset += 2;

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_tr, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_reserved, tvb, offset, 2, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_vlan_flags_designated_vlan, tvb, offset, 2, ENC_BIG_ENDIAN);

}

static void

parse_vlan_bitmap(proto_item *item, tvbuff_t *tvb, unsigned vlan, int offset, int sublen)

{

    int range=0, next=0;

    uint8_t mask, bitmap, i;

    while (sublen>0) {

        bitmap = tvb_get_uint8(tvb, offset);

        mask = 0x80;

        for (i=0; i<8; i++) {

           if (bitmap & mask) {

               if (range==0) {

                   proto_item_append_text(item, "%s%u", next++ ? ", " : "", vlan);

               }

               range++;

           } else {

               if (range>1) {

                   proto_item_append_text(item, "-%u", vlan-1);

               }

               range=0;

           }

           vlan++;

           mask>>=1;

        }

        offset++;

        sublen--;

    }

    if (range>1) {

        proto_item_append_text(item, "-%u", vlan-1);

    }

}

static void

dissect_hello_mt_port_cap_enabled_vlans_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    proto_item *item;

    unsigned vlan;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_enabled_vlans, NULL,

                                "Enabled-VLANs (t=%u, l=%u)", subtype, sublen);

    vlan = tvb_get_ntohs(tvb, offset) & 0xfff;

    offset+=2;

    sublen-=2;

    item = proto_tree_add_string(subtree, hf_isis_hello_enabled_vlans, tvb, offset, sublen, "");

    parse_vlan_bitmap(item, tvb, vlan, offset, sublen);

}

static void

dissect_hello_mt_port_cap_appointedfwrdrs_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_appointedfwrdrs, NULL,

                                "Appointed Forwarders (t=%u, l=%u)", subtype, sublen);

    while (sublen>=6) {

        proto_tree_add_item(subtree, hf_isis_hello_af_nickname, tvb, offset, 2, ENC_BIG_ENDIAN);

        proto_tree_add_item(subtree, hf_isis_hello_af_start_vlan, tvb, offset+2, 2, ENC_BIG_ENDIAN);

        proto_tree_add_item(subtree, hf_isis_hello_af_end_vlan, tvb, offset+4, 2, ENC_BIG_ENDIAN);

        offset += 6;

        sublen -=6;

    }

}

static void

dissect_hello_mt_port_cap_port_trill_ver_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_port_trill_ver, NULL,

                                "Port TRILL Version (t=%u, l=%u)", subtype, sublen);

    proto_tree_add_item(subtree, hf_isis_hello_trill_version, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset++;

    proto_tree_add_item(subtree, hf_isis_hello_trill_hello_reduction, tvb, offset, 4, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_trill_unassigned_1, tvb, offset, 4, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_trill_hop_by_hop_flags, tvb, offset, 4, ENC_BIG_ENDIAN);

    proto_tree_add_item(subtree, hf_isis_hello_trill_unassigned_2, tvb, offset, 4, ENC_BIG_ENDIAN);

}

static void

dissect_hello_mt_port_cap_vlans_appointed_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, int subtype, int sublen)

{

    proto_tree *subtree;

    proto_item *item;

    unsigned vlan;

    subtree = proto_tree_add_subtree_format( tree, tvb, offset-2, sublen+2, ett_isis_hello_clv_mt_port_cap_vlans_appointed, NULL,

                                "Appointed VLANs (t=%u, l=%u)", subtype, sublen);

    vlan = tvb_get_ntohs(tvb, offset) & 0xfff;

    offset+=2;

    sublen-=2;

    item = proto_tree_add_string(subtree, hf_isis_hello_appointed_vlans, tvb, offset, sublen, "");

    parse_vlan_bitmap(item, tvb, vlan, offset, sublen);

}

static void

dissect_hello_mt_port_cap_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    if (length >= 2) {

        /* mtid */

        proto_tree_add_item(tree, hf_isis_hello_mtid, tvb, offset, 2, ENC_BIG_ENDIAN);

        length -= 2;

        offset += 2;

        while (length >= 2) {

            uint8_t subtype   = tvb_get_uint8(tvb, offset);

            uint8_t subtlvlen = tvb_get_uint8(tvb, offset+1);

            length -= 2;

            offset += 2;

            if (subtlvlen > length) {

                proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                                      "Short type %d TLV (%d vs %d)", subtype, subtlvlen, length);

                return;

            }

            switch(subtype)

            {

            case 1:  /* TRILL Special VLANs and Flags */

                dissect_hello_mt_port_cap_vlan_flags_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 2:  /* TRILL Enabled VLANs */

                dissect_hello_mt_port_cap_enabled_vlans_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 3:  /* TRILL Appointed Forwarders */

                dissect_hello_mt_port_cap_appointedfwrdrs_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 4:  /* SPB MCID */

                dissect_hello_mt_port_cap_spb_mcid_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 5:  /* SPB Digest */

                dissect_hello_mt_port_cap_spb_digest_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 6:  /* SPB BVID Tuples */

                dissect_hello_mt_port_cap_spb_bvid_tuples_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 7:  /* Port TRILL Version */

                dissect_hello_mt_port_cap_port_trill_ver_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            case 8:  /* TRILL VLANs Appointed */

                dissect_hello_mt_port_cap_vlans_appointed_clv(tvb, pinfo, tree, offset, subtype, subtlvlen);

                break;

            default:

                proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_subtlv, tvb, offset-2, subtlvlen+2,

                         "Unknown Sub-TLV: Type: %d, Length: %d", subtype, subtlvlen );

            }

            length -= subtlvlen;

            offset += subtlvlen;

        }

    }

}

/*

 * The Restart CLV is documented in RFC 3847 (Restart Signaling for

 * Intermediate System to Intermediate System).  The CLV looks like this

 *

 *  Type   211

 *  Length # of octets in the value field (1 to (3 + ID Length))

 *  Value

 *

 *                                    No. of octets

 *     +-----------------------+

 *     |   Flags               |     1

 *     +-----------------------+

 *     | Remaining Time        |     2

 *     +-----------------------+

 *     | Restarting Neighbor ID|     ID Length

 *     +-----------------------+

 *

 *   Flags (1 octet)

 *

 *      0  1  2  3  4  5  6  7

 *     +--+--+--+--+--+--+--+--+

 *     |  Reserved    |SA|RA|RR|

 *     +--+--+--+--+--+--+--+--+

 *

 *     RR - Restart Request

 *     RA - Restart Acknowledgement

 *     SA - Suppress adjacency advertisement

 *

 * The Remaining Time and Restarting Neighbor ID fields are only required when

 * the RA flag is set.  The Flags field is always required.

 *

 */

/*

 * Name: dissect_hello_restart_clv()

 *

 * Description:

 *    Decode for a restart clv - only found in IIHs

 *      hence no call in the common clv dissector

 *

 */

static void

dissect_hello_restart_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, isis_data_t *isis, int length)

{

    int restart_options=0;

    proto_item *hold_time_item;

    if (length >= 1) {

        static int * const flags[] = {

            &hf_isis_hello_clv_restart_flags_sa,

            &hf_isis_hello_clv_restart_flags_ra,

            &hf_isis_hello_clv_restart_flags_rr,

            NULL

        };

        restart_options = tvb_get_uint8(tvb, offset);

        proto_tree_add_bitmask_with_flags(tree, tvb, offset, hf_isis_hello_clv_restart_flags, ett_isis_hello_clv_restart_flags, flags, ENC_NA, BMT_NO_FALSE|BMT_NO_TFS);

    }

    /* The Remaining Time field should only be present if the RA flag is

     * set

     */

    if (length >= 3 && ISIS_MASK_RESTART_RA(restart_options)) {

        hold_time_item = proto_tree_add_item( tree, hf_isis_hello_clv_restart_remain_time,

            tvb, offset+1, 2, ENC_BIG_ENDIAN );

        proto_item_append_text( hold_time_item, "s" );

    }

    /* The Restarting Neighbor ID should only be present if the RA flag is

     * set.

     */

    if (length >= 3 + isis->system_id_len && ISIS_MASK_RESTART_RA(restart_options)) {

        proto_tree_add_item( tree, hf_isis_hello_clv_restart_neighbor, tvb, offset+3, isis->system_id_len, ENC_NA);

    }

}

/*

 * Name: dissect_hello_nlpid_clv()

 *

 * Description:

 *    Decode for a hello packets NLPID clv.  Calls into the

 *    clv common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_nlpid_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_nlpid_clv(tvb, tree, ett_isis_hello_clv_nlpid_nlpid, hf_isis_hello_clv_nlpid_nlpid, offset, length);

}

/*

 * Name: dissect_hello_mt_clv()

 *

 * Description:

 *    Decode for a hello packets Multi Topology clv.  Calls into the

 *    clv common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_mt_clv(tvbuff_t *tvb, packet_info* pinfo,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_mt_clv(tvb, pinfo, tree, offset, length,

        hf_isis_hello_clv_mt, &ei_isis_hello_clv_mt);

}

/*

 * Name: dissect_hello_ip_int_addr_clv()

 *

 * Description:

 *    Decode for a hello packets ip interface addr clv.  Calls into the

 *    clv common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_ip_int_addr_clv(tvbuff_t *tvb, packet_info* pinfo,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_ip_int_clv(tree, pinfo, tvb, &ei_isis_hello_short_clv,

        offset, length, hf_isis_hello_clv_ipv4_int_addr );

}

/*

 * Name: dissect_hello_ipv6_int_addr_clv()

 *

 * Description:

 *    Decode for a hello packets ipv6 interface addr clv.  Calls into the

 *    clv common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_ipv6_int_addr_clv(tvbuff_t *tvb, packet_info* pinfo,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_ipv6_int_clv(tree, pinfo, tvb, &ei_isis_hello_short_clv,

        offset, length, hf_isis_hello_clv_ipv6_int_addr );

}

/*

 * Name: dissect_hello_authentication_clv()

 *

 * Description:

 *    Decode for a hello packets authentication clv.

 *      Calls into the CLV common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_authentication_clv(tvbuff_t *tvb, packet_info* pinfo,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_authentication_clv(tree, pinfo, tvb, hf_isis_hello_authentication, hf_isis_clv_key_id, &ei_isis_hello_authentication, offset, length);

}

/*

 * Name: dissect_hello_ip_authentication_clv()

 *

 * Description:

 *    Decode for a hello packets IP authentication clv.

 *      Calls into the CLV common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_ip_authentication_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    if ( length != 0 ) {

       proto_tree_add_item( tree, hf_isis_hello_clv_ip_authentication, tvb, offset, length, ENC_ASCII);

    }

}

/*

 * Name: dissect_hello_trill_neighbor_clv

 */

static void

dissect_hello_trill_neighbor_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, isis_data_t *isis _U_, int length) {

    uint8_t size = (tvb_get_uint8(tvb, offset)) & 0x1f;

    if(size==0)

        size=6;

    proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_sf, tvb, offset, 1, ENC_NA);

    proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_lf, tvb, offset, 1, ENC_NA);

    proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_size, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset++;

    length--;

    while(length>=(size+3)) {

        proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_ff, tvb, offset, 1, ENC_NA);

        proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_of, tvb, offset, 1, ENC_NA);

        proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_reserved, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset++;

        length--;

        proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_mtu, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        length -= 2;

        proto_tree_add_item(tree, hf_isis_hello_trill_neighbor_snpa, tvb, offset, 6, ENC_NA);

        offset += 6;

        length -= 6;

    }

}

/*

 * Name: dissect_hello_reverse_metric_clv

 */

static void

dissect_hello_reverse_metric_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, isis_data_t *isis _U_, int length _U_) {

    uint32_t sub_length;

    static int * const flags[] = {

        &hf_isis_hello_reverse_metric_flag_reserved,

        &hf_isis_hello_reverse_metric_flag_u,

        &hf_isis_hello_reverse_metric_flag_w,

        NULL

    };

    proto_tree_add_bitmask(tree, tvb, offset, hf_isis_hello_reverse_metric_flags, ett_isis_hello_reverse_metric_flags, flags, ENC_NA);

    offset += 1;

    proto_tree_add_item(tree, hf_isis_hello_reverse_metric_metric, tvb, offset, 3, ENC_BIG_ENDIAN);

    offset += 3;

    proto_tree_add_item_ret_uint(tree, hf_isis_hello_reverse_metric_sub_length, tvb, offset, 1, ENC_BIG_ENDIAN, &sub_length);

    offset += 1;

    if (sub_length > 0) {

        proto_tree_add_item(tree, hf_isis_hello_reverse_metric_sub_data, tvb, offset, sub_length, ENC_NA);

    }

}

/*

 * Name: dissect_hello_bfd_enabled_clv

 *

 * Description:

 *    Decode for a hello packets BFD enabled clv.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_bfd_enabled_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

        proto_tree *tree, int offset, isis_data_t *isis _U_, int length) {

    while (length >= 3) {

        /* mtid */

        proto_tree_add_item(tree, hf_isis_hello_mtid, tvb, offset, 2, ENC_BIG_ENDIAN);

        length -= 2;

        offset += 2;

        /* nlpid */

        proto_tree_add_item(tree, hf_isis_hello_bfd_enabled_nlpid, tvb, offset, 1, ENC_NA);

        length -= 1;

        offset += 1;

    };

}

/*

 * Name: dissect_hello_checksum_clv()

 *

 * Description:

 *      dump and verify the optional checksum in TLV 12

 *

 * Input:

 *      tvbuff_t * : tvbuffer for packet data

 *      proto_tree * : protocol display tree to fill out.  May be NULL

 *      int : offset into packet data where we are.

 *      int : length of clv we are decoding

 *

 * Output:

 *      void, but we will add to proto tree if !NULL.

 */

static void

dissect_hello_checksum_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, isis_data_t *isis, int length) {

    uint16_t checksum, cacl_checksum=0;

    if ( length != 2 ) {

        proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, length,

                                "incorrect checksum length (%u), should be (2)", length );

        return;

    }

    checksum = tvb_get_ntohs(tvb, offset);

    if (checksum == 0) {

        /* No checksum present */

        proto_tree_add_checksum(tree, tvb, offset, hf_isis_hello_checksum, hf_isis_hello_checksum_status, &ei_isis_hello_bad_checksum, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NOT_PRESENT);

    } else {

        if (osi_check_and_get_checksum(tvb, 0, isis->pdu_length, offset, &cacl_checksum)) {

            /* Successfully processed checksum, verify it */

            proto_tree_add_checksum(tree, tvb, offset, hf_isis_hello_checksum, hf_isis_hello_checksum_status, &ei_isis_hello_bad_checksum, pinfo, cacl_checksum, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);

        } else {

            /* We didn't capture the entire packet, so we can't verify it */

            proto_tree_add_checksum(tree, tvb, offset, hf_isis_hello_checksum, hf_isis_hello_checksum_status, &ei_isis_hello_bad_checksum, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);

        }

    }

}

/*

 * Name: dissect_hello_area_address_clv()

 *

 * Description:

 *    Decode for a hello packets area address clv.

 *      Calls into the CLV common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_area_address_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_area_address_clv(tree, pinfo, tvb, &ei_isis_hello_short_clv, hf_isis_hello_area_address, offset, length);

}

/*

 * Name: dissect_hello_instance_identifier_clv()

 *

 * Description:

 *    Decode for a hello packets Instance Identifier clv.

 *      Calls into the CLV common one.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_instance_identifier_clv(tvbuff_t *tvb, packet_info* pinfo _U_,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_instance_identifier_clv(tree, pinfo, tvb, &ei_isis_hello_short_clv, hf_isis_hello_instance_identifier, hf_isis_hello_supported_itid, offset, length);

}

static const value_string adj_state_vals[] = {

    { 0, "Up" },

    { 1, "Initializing" },

    { 2, "Down" },

    { 0, NULL }

};

static void

dissect_hello_ptp_adj_clv(tvbuff_t *tvb, packet_info* pinfo,

        proto_tree *tree, int offset, isis_data_t *isis, int length)

{

    switch(length)

    {

    case 1:

        proto_tree_add_item(tree, hf_isis_hello_adjacency_state, tvb, offset, 1, ENC_BIG_ENDIAN);

        break;

    case 5:

        proto_tree_add_item(tree, hf_isis_hello_adjacency_state, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item(tree, hf_isis_hello_extended_local_circuit_id, tvb, offset+1, 4, ENC_BIG_ENDIAN);

        break;

    case 11:

        proto_tree_add_item(tree, hf_isis_hello_adjacency_state, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item(tree, hf_isis_hello_extended_local_circuit_id, tvb, offset+1, 4, ENC_BIG_ENDIAN);

        proto_tree_add_item(tree, hf_isis_hello_neighbor_systemid, tvb, offset+5, isis->system_id_len, ENC_NA);

    break;

    case 15:

        proto_tree_add_item(tree, hf_isis_hello_adjacency_state, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item(tree, hf_isis_hello_extended_local_circuit_id, tvb, offset+1, 4, ENC_BIG_ENDIAN);

        proto_tree_add_item(tree, hf_isis_hello_neighbor_systemid, tvb, offset+5, isis->system_id_len, ENC_NA);

        proto_tree_add_item(tree, hf_isis_hello_neighbor_extended_local_circuit_id, tvb, offset+5+isis->system_id_len, 4, ENC_BIG_ENDIAN);

    break;

    default:

        proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                   "malformed TLV (%d vs 1,5,11,15)", length );

    }

}

/*

 * Name: isis_dissect_is_neighbors_clv()

 *

 * Description:

 *    Take apart a IS neighbor packet.  A neighbor is n 6 byte packets.

 *    (they tend to be an 802.3 MAC address, but it's not required).

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : protocol display tree to fill out.  May be NULL

 *    int : offset into packet data where we are.

 *    int : length of IDs in packet.

 *    int : length of clv we are decoding

 *

 * Output:

 *    void, but we will add to proto tree if !NULL.

 */

static void

dissect_hello_is_neighbors_clv(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, int offset,

    isis_data_t *isis _U_, int length)

{

    while ( length > 0 ) {

        if (length<6) {

            proto_tree_add_expert_format(tree, pinfo, &ei_isis_hello_short_clv, tvb, offset, -1,

                "short is neighbor (%d vs 6)", length );

            return;

        }

        /*

         * Lets turn the area address into "standard" 0000.0000.etc

         * format string.

         */

        proto_tree_add_item(tree, hf_isis_hello_is_neighbor, tvb, offset, 6, ENC_NA);

        offset += 6;

        length -= 6;

    }

}

/*

 * Name: dissect_hello_padding_clv()

 *

 * Description:

 *    Decode for a hello packet's padding clv.  Padding does nothing,

 *    so we just return.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void

 */

static void

dissect_hello_padding_clv(tvbuff_t *tvb _U_, packet_info* pinfo _U_, proto_tree *tree _U_, int offset _U_,

    isis_data_t *isis _U_, int length _U_)

{

    /* nothing to do here! */

}

/*

 * Name: dissect_hello_ipv6_glb_int_addr_clv()

 *

 * Description:

 *    Decode for a hello packets ipv6 gobal interface addr clv.  Calls into the

 *    clv 233.

 *

 * Input:

 *    tvbuff_t * : tvbuffer for packet data

 *    proto_tree * : proto tree to build on (may be null)

 *    int : current offset into packet data

 *    int : length of IDs in packet.

 *    int : length of this clv

 *

 * Output:

 *    void, will modify proto_tree if not null.

 */

static void

dissect_hello_ipv6_glb_int_addr_clv(tvbuff_t *tvb, packet_info* pinfo,

    proto_tree *tree, int offset, isis_data_t *isis _U_, int length)

{

    isis_dissect_ipv6_int_clv(tree, pinfo, tvb, &ei_isis_hello_short_clv,

        offset, length, hf_isis_hello_clv_ipv6_glb_int_addr );

}

static const isis_clv_handle_t clv_l1_hello_opts[] = {

    {

        ISIS_CLV_AREA_ADDRESS,

        "Area address(es)",

        &ett_isis_hello_clv_area_addr,

        dissect_hello_area_address_clv

    },

    {

        ISIS_CLV_IS_NEIGHBORS,

        "IS Neighbor(s)",

        &ett_isis_hello_clv_is_neighbors,

        dissect_hello_is_neighbors_clv

    },

    {

        ISIS_CLV_INSTANCE_IDENTIFIER,

        "Instance Identifier",

        &ett_isis_hello_clv_instance_identifier,

        dissect_hello_instance_identifier_clv

    },

    {

        ISIS_CLV_PADDING,

        "Padding",

        &ett_isis_hello_clv_padding,

        dissect_hello_padding_clv

    },

    {

        ISIS_CLV_PROTOCOLS_SUPPORTED,

        "Protocols Supported",

        &ett_isis_hello_clv_nlpid,

        dissect_hello_nlpid_clv

    },

    {

        ISIS_CLV_IP_ADDR,

        "IP Interface address(es)",

        &ett_isis_hello_clv_ipv4_int_addr,

        dissect_hello_ip_int_addr_clv

    },

    {

        ISIS_CLV_IP6_ADDR,

        "IPv6 Interface address(es)",

        &ett_isis_hello_clv_ipv6_int_addr,

        dissect_hello_ipv6_int_addr_clv

    },

    {

        ISIS_CLV_RESTART,

        "Restart Signaling",

        &ett_isis_hello_clv_restart,

        dissect_hello_restart_clv

    },

    {

        ISIS_CLV_AUTHENTICATION,

        "Authentication",

        &ett_isis_hello_clv_authentication,

        dissect_hello_authentication_clv

    },

    {

        ISIS_CLV_IP_AUTHENTICATION,

        "IP Authentication",

        &ett_isis_hello_clv_ip_authentication,

        dissect_hello_ip_authentication_clv

    },

    {