/* packet-nhrp.c

 * Routines for NBMA Next Hop Resolution Protocol

 * RFC 2332 plus Cisco extensions:

 *     I-D draft-detienne-dmvpn-01: Flexible Dynamic Mesh VPN

 *     others?  (documented where?)

 * plus extensions from:

 *     RFC 2520: NHRP with Mobile NHCs

 *     RFC 2735: NHRP Support for Virtual Private Networks

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

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

 *

 * CIE decoding for extensions and Cisco 12.4T extensions

 * added by Timo Teras <timo.teras@iki.fi>

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/prefs.h>

#include <epan/addr_resolv.h>

#include <epan/expert.h>

#include <epan/etypes.h>

#include <epan/ipproto.h>

#include <epan/nlpid.h>

#include <epan/afn.h>

#include <epan/in_cksum.h>

#include "packet-iana-oui.h"

#include "packet-llc.h"

#include "packet-gre.h"

void proto_register_nhrp(void);

void proto_reg_handoff_nhrp(void);

static dissector_handle_t nhrp_handle;

/* forward reference */

static void _dissect_nhrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,

    bool nested, bool codeinfo);

static int proto_nhrp;

static int hf_nhrp_hdr_afn;

static int hf_nhrp_hdr_pro_type;

static int hf_nhrp_hdr_pro_snap_oui;

static int hf_nhrp_hdr_pro_snap_pid;

static int hf_nhrp_hdr_hopcnt;

static int hf_nhrp_hdr_pktsz;

static int hf_nhrp_hdr_chksum;

static int hf_nhrp_hdr_chksum_status;

static int hf_nhrp_hdr_extoff;

static int hf_nhrp_hdr_version;

static int hf_nhrp_hdr_op_type;

static int hf_nhrp_hdr_shtl;

static int hf_nhrp_hdr_shtl_type;

static int hf_nhrp_hdr_shtl_len;

static int hf_nhrp_hdr_sstl;

static int hf_nhrp_hdr_sstl_type;

static int hf_nhrp_hdr_sstl_len;

static int hf_nhrp_src_proto_len;

static int hf_nhrp_dst_proto_len;

static int hf_nhrp_flags;

static int hf_nhrp_flag_Q;

static int hf_nhrp_flag_N;

static int hf_nhrp_flag_A;

static int hf_nhrp_flag_D;

static int hf_nhrp_flag_U1;

static int hf_nhrp_flag_U2;

static int hf_nhrp_flag_S;

static int hf_nhrp_flag_NAT;

static int hf_nhrp_src_nbma_addr;

static int hf_nhrp_src_nbma_saddr;

static int hf_nhrp_src_prot_addr;

static int hf_nhrp_dst_prot_addr;

static int hf_nhrp_request_id;

static int hf_nhrp_code;

static int hf_nhrp_prefix_len;

static int hf_nhrp_unused;

static int hf_nhrp_mtu;

static int hf_nhrp_holding_time;

static int hf_nhrp_cli_addr_tl;

static int hf_nhrp_cli_addr_tl_type;

static int hf_nhrp_cli_addr_tl_len;

static int hf_nhrp_cli_saddr_tl;

static int hf_nhrp_cli_saddr_tl_type;

static int hf_nhrp_cli_saddr_tl_len;

static int hf_nhrp_cli_prot_len;

static int hf_nhrp_pref;

static int hf_nhrp_client_nbma_addr;

static int hf_nhrp_client_nbma_saddr;

static int hf_nhrp_client_prot_addr;

static int hf_nhrp_ext_C;

static int hf_nhrp_ext_type;

static int hf_nhrp_ext_len;

/* static int hf_nhrp_ext_value; */          /* TBD: Not used */

static int hf_nhrp_error_code;

static int hf_nhrp_error_offset;

static int hf_nhrp_traffic_code;

/* static int hf_nhrp_error_packet; */       /* TBD: Not used */

static int hf_nhrp_auth_ext_reserved;

static int hf_nhrp_auth_ext_spi;

static int hf_nhrp_auth_ext_src_addr;

static int hf_nhrp_vendor_ext_id;

static int hf_nhrp_devcap_ext_srccap;

static int hf_nhrp_devcap_ext_srccap_V;

static int hf_nhrp_devcap_ext_dstcap;

static int hf_nhrp_devcap_ext_dstcap_V;

static int hf_nhrp_unknown_ext_value;

/* Generated from convert_proto_tree_add_text.pl */

static int hf_nhrp_dst_prot_addr_bytes;

static int hf_nhrp_auth_ext_src_addr_bytes;

static int hf_nhrp_vendor_ext_data;

static int hf_nhrp_protocol_type;

static int hf_nhrp_src_nbma_addr_bytes;

static int hf_nhrp_client_nbma_address_bytes;

static int hf_nhrp_client_prot_addr_bytes;

static int hf_nhrp_auth_data;

static int hf_nhrp_src_prot_addr_bytes;

static int ett_nhrp;

static int ett_nhrp_hdr;

static int ett_nhrp_hdr_shtl;

static int ett_nhrp_hdr_sstl;

static int ett_nhrp_mand;

static int ett_nhrp_ext;

static int ett_nhrp_mand_flag;

static int ett_nhrp_cie;

static int ett_nhrp_cie_cli_addr_tl;

static int ett_nhrp_cie_cli_saddr_tl;

static int ett_nhrp_indication;

static int ett_nhrp_auth_ext;

static int ett_nhrp_vendor_ext;

static int ett_nhrp_devcap_ext;

static int ett_nhrp_devcap_ext_srccap;

static int ett_nhrp_devcap_ext_dstcap;

static expert_field ei_nhrp_hdr_pktsz;

static expert_field ei_nhrp_hdr_extoff;

static expert_field ei_nhrp_hdr_chksum;

static expert_field ei_nhrp_ext_not_allowed;

static expert_field ei_nhrp_ext_malformed;

static expert_field ei_nhrp_ext_extra;

static bool pref_auth_ext_has_addr = true;

/* NHRP Packet Types */

#define NHRP_RESOLUTION_REQ     1

#define NHRP_RESOLUTION_REPLY   2

#define NHRP_REGISTRATION_REQ   3

#define NHRP_REGISTRATION_REPLY 4

#define NHRP_PURGE_REQ          5

#define NHRP_PURGE_REPLY        6

#define NHRP_ERROR_INDICATION   7

#define NHRP_TRAFFIC_INDICATION 8

/* NHRP Extension Types */

#define NHRP_EXT_NULL              0   /* End of Extension */

#define NHRP_EXT_RESP_ADDR         3   /* Responder Address Extension */

#define NHRP_EXT_FWD_RECORD        4   /* NHRP Forward Transit NHS Record Extension */

#define NHRP_EXT_REV_RECORD        5   /* NHRP Reverse Transit NHS Record Extension */

#define NHRP_EXT_AUTH              7   /* NHRP Authentication Extension */

#define NHRP_EXT_VENDOR_PRIV       8   /* NHRP Vendor Private Extension */

#define NHRP_EXT_NAT_ADDRESS       9   /* Cisco NAT Address Extension */

#define NHRP_EXT_DEV_CAPABILITIES  9   /* RFC 2735: Device Capabilities Extension */

#define NHRP_EXT_MOBILE_AUTH      10   /* RFC 2520: NHRP Mobile NHC Authentication Extension */

/* NHRP Error Codes */

#define NHRP_ERR_UNRECOGNIZED_EXT       0x0001

#define NHRP_ERR_NHRP_LOOP_DETECT       0x0003

#define NHRP_ERR_PROT_ADDR_UNREACHABLE  0x0006

#define NHRP_ERR_PROT_ERROR             0x0007

#define NHRP_ERR_SDU_SIZE_EXCEEDED      0x0008

#define NHRP_ERR_INV_EXT                0x0009

#define NHRP_ERR_INV_RESOLUTION_REPLY   0x000a

#define NHRP_ERR_AUTH_FAILURE           0x000b

#define NHRP_ERR_HOP_COUNT_EXCEEDED     0x000f

#define NHRP_ERR_VPN_MISMATCH           0x0010  /* RFC 2735 */

#define NHRP_ERR_VPN_UNSUPPORTED        0x0011  /* RFC 2735 */

/* NHRP CIE codes */

#define NHRP_CODE_SUCCESS                   0x00

#define NHRP_CODE_ADMIN_PROHIBITED          0x04

#define NHRP_CODE_INSUFFICIENT_RESOURCES    0x05

#define NHRP_CODE_NO_BINDING_EXISTS         0x0c

#define NHRP_CODE_NON_UNIQUE_BINDING        0x0d

#define NHRP_CODE_ALREADY_REGISTERED        0x0e

/* NHRP Subnetwork layer address type/length */

#define NHRP_SHTL_TYPE_MASK 0x40

#define NHRP_SHTL_LEN_MASK  0x3F

#define NHRP_SHTL_TYPE(val) (((val) & (NHRP_SHTL_TYPE_MASK)) >> 6)

#define NHRP_SHTL_LEN(val)  ((val) & (NHRP_SHTL_LEN_MASK))

#define NHRP_SHTL_TYPE_NSAP 0

#define NHRP_SHTL_TYPE_E164 1

static const value_string nhrp_shtl_type_vals[] = {

    { NHRP_SHTL_TYPE_NSAP, "NSAP format" },

    { NHRP_SHTL_TYPE_E164, "Native E.164 format" },

    { 0, NULL }

};

static const value_string nhrp_op_type_vals[] = {

    { NHRP_RESOLUTION_REQ,      "NHRP Resolution Request" },

    { NHRP_RESOLUTION_REPLY,    "NHRP Resolution Reply" },

    { NHRP_REGISTRATION_REQ,    "NHRP Registration Request" },

    { NHRP_REGISTRATION_REPLY,  "NHRP Registration Reply" },

    { NHRP_PURGE_REQ,           "NHRP Purge Request" },

    { NHRP_PURGE_REPLY,         "NHRP Purge Reply" },

    { NHRP_ERROR_INDICATION,    "NHRP Error Indication" },

    { NHRP_TRAFFIC_INDICATION,  "NHRP Traffic Indication" },

    { 0,                        NULL }

};

static const value_string ext_type_vals[] = {

    { NHRP_EXT_NULL,            "End of Extension" },

    { NHRP_EXT_RESP_ADDR,       "Responder Address Extension" },

    { NHRP_EXT_FWD_RECORD,      "Forward Transit NHS Record Extension" },

    { NHRP_EXT_REV_RECORD,      "Reverse Transit NHS Record Extension" },

    { NHRP_EXT_AUTH,            "NHRP Authentication Extension" },

    { NHRP_EXT_VENDOR_PRIV,     "NHRP Vendor Private Extension" },

    { NHRP_EXT_NAT_ADDRESS,     "Cisco NAT Address Extension" },

#if 0 /* Dup (which is handled in the code) */

    { NHRP_EXT_DEV_CAPABILITIES,"Device Capabilities Extension" },

#endif

    { NHRP_EXT_MOBILE_AUTH,     "Mobile NHC Authentication Extension" },

    { 0,                        NULL }

};

static const value_string nhrp_error_code_vals[] = {

    { NHRP_ERR_UNRECOGNIZED_EXT,        "Unrecognized Extension" },

    { NHRP_ERR_NHRP_LOOP_DETECT,        "NHRP Loop Detected" },

    { NHRP_ERR_PROT_ADDR_UNREACHABLE,   "Protocol Address Unreachable" },

    { NHRP_ERR_PROT_ERROR,              "Protocol Error" },

    { NHRP_ERR_SDU_SIZE_EXCEEDED,       "NHRP SDU Size Exceeded" },

    { NHRP_ERR_INV_EXT,                 "Invalid Extension" },

    { NHRP_ERR_INV_RESOLUTION_REPLY,    "Invalid NHRP Resolution Reply Received" },

    { NHRP_ERR_AUTH_FAILURE,            "Authentication Failure" },

    { NHRP_ERR_HOP_COUNT_EXCEEDED,      "Hop Count Exceeded" },

    { NHRP_ERR_VPN_MISMATCH,            "VPN Mismatch" },

    { NHRP_ERR_VPN_UNSUPPORTED,         "VPN Unsupported" },

    { 0,                                NULL }

};

static const value_string nhrp_traffic_code_vals[] = {

    { 0, "NHRP traffic redirect/indirection" },

    { 0, NULL }

};

static const value_string nhrp_cie_code_vals[] = {

    { NHRP_CODE_SUCCESS,                "Success" },

    { NHRP_CODE_ADMIN_PROHIBITED,       "Administratively Prohibited" },

    { NHRP_CODE_INSUFFICIENT_RESOURCES, "Insufficient Resources" },

    { NHRP_CODE_NO_BINDING_EXISTS,      "No Interworking Layer Address to NBMA Address Binding Exists" },

    { NHRP_CODE_NON_UNIQUE_BINDING,     "Binding Exists But Is Not Unique" },

    { NHRP_CODE_ALREADY_REGISTERED,     "Unique Internetworking Layer Address Already Registered" },

    { 0,                                NULL }

};

static dissector_table_t osinl_incl_subdissector_table;

static dissector_table_t osinl_excl_subdissector_table;

static dissector_table_t ethertype_subdissector_table;

/*

 * The header fields needed outside of dissect_nhrp_hdr().

 * This is not all of the fields.

 */

typedef struct _e_nhrp {

    uint16_t ar_afn;

    uint16_t ar_pro_type;

    uint32_t ar_pro_type_oui;

    uint16_t ar_pro_type_pid;

    uint8_t ar_op_type;

    uint8_t ar_shtl;

    uint8_t ar_sstl;

} e_nhrp_hdr;

static bool dissect_nhrp_hdr(tvbuff_t     *tvb,

                      packet_info  *pinfo,

                      proto_tree   *tree,

                      int          *pOffset,

                      int          *pMandLen,

                      int          *pExtLen,

                      oui_info_t  **pOuiInfo,

                      e_nhrp_hdr   *hdr)

{

    int          offset    = *pOffset;

    const char *pro_type_str;

    proto_tree *nhrp_tree;

    proto_item *nhrp_item;

    proto_item *shtl_tree_item;

    proto_tree *shtl_tree;

    proto_item *sstl_tree_item;

    proto_tree *sstl_tree;

    proto_item *ti, *ti_extoff;

    uint32_t    afn;

    uint32_t    oui;

    uint32_t    pid;

    uint32_t    pktsz;

    uint32_t    extoff;

    uint8_t     version;

    nhrp_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_nhrp_hdr, &nhrp_item, "NHRP Fixed Header");

    proto_tree_add_item_ret_uint(nhrp_tree, hf_nhrp_hdr_afn, tvb, offset, 2, ENC_BIG_ENDIAN, &afn);

    hdr->ar_afn = (uint16_t)afn;

    offset += 2;

    /* XXX - range_string? */

    hdr->ar_pro_type = tvb_get_ntohs(tvb, offset);

    if (hdr->ar_pro_type <= 0xFF) {

        /* It's an NLPID */

        pro_type_str = val_to_str_const(hdr->ar_pro_type, nlpid_vals,

            "Unknown NLPID");

    } else if (hdr->ar_pro_type <= 0x3FF) {

        /* Reserved for future use by the IETF */

        pro_type_str = "Reserved for future use by the IETF";

    } else if (hdr->ar_pro_type <= 0x04FF) {

        /* Allocated for use by the ATM Forum */

        pro_type_str = "Allocated for use by the ATM Forum";

    } else if (hdr->ar_pro_type <= 0x05FF) {

        /* Experimental/Local use */

        pro_type_str = "Experimental/Local use";

    } else {

        pro_type_str = val_to_str_const(hdr->ar_pro_type, etype_vals,

            "Unknown Ethertype");

    }

    proto_tree_add_uint_format_value(nhrp_tree, hf_nhrp_hdr_pro_type, tvb, offset, 2,

        hdr->ar_pro_type, "%s (0x%04x)",

        pro_type_str, hdr->ar_pro_type);

    offset += 2;

    if (hdr->ar_pro_type == NLPID_SNAP) {

        /*

         * The long form protocol type is a SNAP OUI and PID.

         */

        proto_tree_add_item_ret_uint(nhrp_tree, hf_nhrp_hdr_pro_snap_oui,

            tvb, offset, 3, hdr->ar_pro_type_oui, &oui);

        offset += 3;

        hdr->ar_pro_type_oui = oui;

        *pOuiInfo = get_snap_oui_info(hdr->ar_pro_type_oui);

        if (*pOuiInfo != NULL) {

            proto_tree_add_item_ret_uint(nhrp_tree,

                *(*pOuiInfo)->field_info->p_id,

                tvb, offset, 2, ENC_BIG_ENDIAN, &pid);

        } else {

            proto_tree_add_item_ret_uint(nhrp_tree, hf_nhrp_hdr_pro_snap_pid,

                tvb, offset, 2, ENC_BIG_ENDIAN, &pid);

        }

        hdr->ar_pro_type_pid = (uint16_t)pid;

    } else {

        /*

         * XXX - we should check that this is zero, as RFC 2332

         * says it should be zero.

         */

        proto_tree_add_item(nhrp_tree, hf_nhrp_protocol_type, tvb, offset, 5, ENC_NA);

        offset += 5;

    }

    proto_tree_add_item(nhrp_tree, hf_nhrp_hdr_hopcnt, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    ti = proto_tree_add_item_ret_uint(nhrp_tree, hf_nhrp_hdr_pktsz, tvb, offset, 2, ENC_BIG_ENDIAN, &pktsz);

    if (pktsz < 20) {

        /*

         * The total packet size isn't large enough for a full header.

         */

        expert_add_info(pinfo, ti, &ei_nhrp_hdr_pktsz);

        proto_item_set_end(nhrp_item, tvb, offset + 2);

        return false;

    }

    offset += 2;

    if (tvb_bytes_exist(tvb, 0, pktsz)) {

        vec_t cksum_vec[1];

        SET_CKSUM_VEC_TVB(cksum_vec[0], tvb, 0, pktsz);

        proto_tree_add_checksum(nhrp_tree, tvb, offset, hf_nhrp_hdr_chksum, hf_nhrp_hdr_chksum_status, &ei_nhrp_hdr_chksum,

                                pinfo, in_cksum(&cksum_vec[0], 1), ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_IN_CKSUM);

    } else {

        proto_tree_add_checksum(nhrp_tree, tvb, offset, hf_nhrp_hdr_chksum, hf_nhrp_hdr_chksum_status, &ei_nhrp_hdr_chksum,

                                pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);

    }

    offset += 2;

    ti_extoff = proto_tree_add_item_ret_uint(nhrp_tree, hf_nhrp_hdr_extoff, tvb, offset, 2, ENC_BIG_ENDIAN, &extoff);

    if (extoff != 0) {

        if (extoff < 20 || extoff > pktsz) {

            /* Bogus value; keep dissecting the header */

            expert_add_info(pinfo, ti_extoff, &ei_nhrp_hdr_extoff);

        }

        switch (hdr->ar_op_type)

        {

        case NHRP_ERROR_INDICATION:

            /* According to RFC 2332, section 5.2.7, there shouldn't be any

             * extensions in the Error Indication packet. */

            expert_add_info(pinfo, ti_extoff, &ei_nhrp_ext_not_allowed);

            break;

        default:

            break;

        }

    }

    offset += 2;

    version = tvb_get_uint8(tvb, offset);

    proto_tree_add_uint_format_value(nhrp_tree, hf_nhrp_hdr_version, tvb, offset, 1,

        version, "%u (%s)", version,

        (version == 1) ? "NHRP - rfc2332" : "Unknown");

    offset += 1;

    proto_tree_add_item(nhrp_tree, hf_nhrp_hdr_op_type, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    hdr->ar_shtl = tvb_get_uint8(tvb, offset);

    shtl_tree_item = proto_tree_add_uint_format_value(nhrp_tree, hf_nhrp_hdr_shtl,

        tvb, offset, 1, hdr->ar_shtl, "%s/%u",

        val_to_str_const(NHRP_SHTL_TYPE(hdr->ar_shtl), nhrp_shtl_type_vals, "Unknown Type"),

        NHRP_SHTL_LEN(hdr->ar_shtl));

    shtl_tree = proto_item_add_subtree(shtl_tree_item, ett_nhrp_hdr_shtl);

    proto_tree_add_item(shtl_tree, hf_nhrp_hdr_shtl_type, tvb, offset, 1, ENC_BIG_ENDIAN);

    proto_tree_add_item(shtl_tree, hf_nhrp_hdr_shtl_len, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    hdr->ar_sstl = tvb_get_uint8(tvb, offset);

    sstl_tree_item = proto_tree_add_uint_format_value(nhrp_tree, hf_nhrp_hdr_sstl,

        tvb, offset, 1, hdr->ar_sstl, "%s/%u",

        val_to_str_const(NHRP_SHTL_TYPE(hdr->ar_sstl), nhrp_shtl_type_vals, "Unknown Type"),

        NHRP_SHTL_LEN(hdr->ar_sstl));

    sstl_tree = proto_item_add_subtree(sstl_tree_item, ett_nhrp_hdr_sstl);

    proto_tree_add_item(sstl_tree, hf_nhrp_hdr_sstl_type, tvb, offset, 1, ENC_BIG_ENDIAN);

    proto_tree_add_item(sstl_tree, hf_nhrp_hdr_sstl_len, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    proto_item_set_end(nhrp_item, tvb, offset);

    *pOffset = offset;

    if (extoff != 0) {

        if (extoff < 20 || extoff > pktsz) {

            /* Bogus value */

            return false;

        }

        *pMandLen = extoff - 20;

        *pExtLen = pktsz - extoff;

    }

    else {

        *pMandLen = pktsz - 20;

        *pExtLen = 0;

    }

    return true;

}

static void dissect_cie_list(tvbuff_t    *tvb,

                      packet_info *pinfo,

                      proto_tree  *tree,

                      int          offset,

                      int          cieEnd,

                      e_nhrp_hdr  *hdr,

                      int          isReq,

                      bool         codeinfo)

{

    proto_item *cli_addr_tree_item;

    proto_tree *cli_addr_tree;

    proto_item *cli_saddr_tree_item;

    proto_tree *cli_saddr_tree;

    uint8_t     val;

    while ((offset + 12)          <= cieEnd) {

        unsigned    cli_addr_len   = tvb_get_uint8(tvb, offset + 8);

        unsigned    cli_saddr_len  = tvb_get_uint8(tvb, offset + 9);

        unsigned    cli_prot_len   = tvb_get_uint8(tvb, offset + 10);

        unsigned    cie_len        = 12 + cli_addr_len + cli_saddr_len + cli_prot_len;

        proto_tree *cie_tree       = proto_tree_add_subtree(tree, tvb, offset, cie_len, ett_nhrp_cie, NULL, "Client Information Entry");

        if (isReq) {

            proto_tree_add_item(cie_tree, hf_nhrp_code, tvb, offset, 1, ENC_BIG_ENDIAN);

        }

        else {

            uint8_t code = tvb_get_uint8(tvb, offset);

            if ( codeinfo ) {

                col_append_fstr(pinfo->cinfo, COL_INFO, ", Code=%s",

                    val_to_str(code, nhrp_cie_code_vals, "Unknown (%u)"));

            }

            proto_tree_add_item(cie_tree, hf_nhrp_code, tvb, offset, 1, ENC_BIG_ENDIAN);

        }

        offset += 1;

        proto_tree_add_item(cie_tree, hf_nhrp_prefix_len, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        proto_tree_add_item(cie_tree, hf_nhrp_unused, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        proto_tree_add_item(cie_tree, hf_nhrp_mtu, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        proto_tree_add_item(cie_tree, hf_nhrp_holding_time, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        val = tvb_get_uint8(tvb, offset);

        cli_addr_tree_item = proto_tree_add_uint_format_value(cie_tree,

            hf_nhrp_cli_addr_tl, tvb, offset, 1, val, "%s/%u",

            val_to_str_const(NHRP_SHTL_TYPE(val), nhrp_shtl_type_vals, "Unknown Type"),

            NHRP_SHTL_LEN(val));

        cli_addr_tree = proto_item_add_subtree(cli_addr_tree_item, ett_nhrp_cie_cli_addr_tl);

        proto_tree_add_item(cli_addr_tree, hf_nhrp_cli_addr_tl_type, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item(cli_addr_tree, hf_nhrp_cli_addr_tl_len, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        val = tvb_get_uint8(tvb, offset);

        cli_saddr_tree_item = proto_tree_add_uint_format_value(cie_tree,

            hf_nhrp_cli_saddr_tl, tvb, offset, 1, val, "%s/%u",

            val_to_str_const(NHRP_SHTL_TYPE(val), nhrp_shtl_type_vals, "Unknown Type"),

            NHRP_SHTL_LEN(val));

        cli_saddr_tree = proto_item_add_subtree(cli_saddr_tree_item, ett_nhrp_cie_cli_saddr_tl);

        proto_tree_add_item(cli_saddr_tree, hf_nhrp_cli_saddr_tl_type, tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_tree_add_item(cli_saddr_tree, hf_nhrp_cli_saddr_tl_len, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        proto_tree_add_item(cie_tree, hf_nhrp_cli_prot_len, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        proto_tree_add_item(cie_tree, hf_nhrp_pref, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        if (cli_addr_len) {

            switch (hdr->ar_afn) {

            case AFNUM_INET:

                if (cli_addr_len == 4)

                    proto_tree_add_item(cie_tree, hf_nhrp_client_nbma_addr, tvb, offset, 4, ENC_BIG_ENDIAN);

                else {

                    proto_tree_add_item(cie_tree, hf_nhrp_client_nbma_address_bytes, tvb, offset, cli_addr_len, ENC_NA);

                }

                break;

            default:

                proto_tree_add_item(cie_tree, hf_nhrp_client_nbma_address_bytes, tvb, offset, cli_addr_len, ENC_NA);

                break;

            }

            offset += cli_addr_len;

        }

        if (cli_saddr_len) {

            proto_tree_add_item(cie_tree, hf_nhrp_client_nbma_saddr, tvb, offset, cli_saddr_len, ENC_NA);

        }

        if (cli_prot_len) {

            if (cli_prot_len == 4)

                proto_tree_add_item(cie_tree, hf_nhrp_client_prot_addr, tvb, offset, 4, ENC_BIG_ENDIAN);

            else {

                proto_tree_add_item(cie_tree, hf_nhrp_client_prot_addr_bytes, tvb, offset, cli_prot_len, ENC_NA);

            }

            offset += cli_prot_len;

        }

    }

}

// NOLINTNEXTLINE(misc-no-recursion)

static void dissect_nhrp_mand(tvbuff_t    *tvb,

                       packet_info *pinfo,

                       proto_tree  *tree,

                       oui_info_t  *oui_info,

                       e_nhrp_hdr  *hdr,

                       unsigned    *srcLen,

                       bool         codeinfo)

{

    int      offset  = 0;

    int      mandEnd = tvb_reported_length(tvb);

    uint8_t  ssl, shl;

    unsigned dstLen;

    proto_tree *nhrp_tree;

    proto_item *nhrp_item;

    proto_tree *ind_tree;

    proto_item *ind_item;

    bool        save_in_error_pkt;

    int         dissected;

    tvbuff_t   *sub_tvb;

    nhrp_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_nhrp_mand, &nhrp_item, "NHRP Mandatory Part");

    /* Src Proto Len, present in all current packet types */

    *srcLen = tvb_get_uint8(tvb, offset);

    proto_tree_add_item(nhrp_tree, hf_nhrp_src_proto_len, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    /* Dst Proto Len, present in all current packet types */

    dstLen = tvb_get_uint8(tvb, offset);

    proto_tree_add_item(nhrp_tree, hf_nhrp_dst_proto_len, tvb, offset, 1, ENC_BIG_ENDIAN);

    offset += 1;

    /*

     * Flags: different flags are used for different packet types, and

     * aren't even present in all packet types.

     *

     * Next 4 bytes: request ID in most packet types, error code and

     * offset in Error Indication, traffic code and unused field in

     * Traffic Indication.

     */

    switch (hdr->ar_op_type)

    {

    case NHRP_RESOLUTION_REQ:

    case NHRP_RESOLUTION_REPLY:

        {

        static int * const flags[] = {

            &hf_nhrp_flag_Q,

            &hf_nhrp_flag_A,

            &hf_nhrp_flag_D,

            &hf_nhrp_flag_U1,

            &hf_nhrp_flag_S,

            &hf_nhrp_flag_NAT,

            NULL

        };

        proto_tree_add_bitmask(nhrp_tree, tvb, offset, hf_nhrp_flags, ett_nhrp_mand_flag, flags, ENC_BIG_ENDIAN);

        offset += 2;

        col_append_fstr(pinfo->cinfo, COL_INFO, ", ID=%u", tvb_get_ntohl(tvb, offset));

        proto_tree_add_item(nhrp_tree, hf_nhrp_request_id, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

        }

        break;

    case NHRP_REGISTRATION_REQ:

    case NHRP_REGISTRATION_REPLY:

        {

        static int * const flags[] = {

            &hf_nhrp_flag_U2,

            &hf_nhrp_flag_NAT,

            NULL

        };

        proto_tree_add_bitmask(nhrp_tree, tvb, offset, hf_nhrp_flags, ett_nhrp_mand_flag, flags, ENC_BIG_ENDIAN);

        offset += 2;

        col_append_fstr(pinfo->cinfo, COL_INFO, ", ID=%u", tvb_get_ntohl(tvb, offset));

        proto_tree_add_item(nhrp_tree, hf_nhrp_request_id, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

        }

        break;

    case NHRP_PURGE_REQ:

    case NHRP_PURGE_REPLY:

        {

        static int * const flags[] = {

            &hf_nhrp_flag_N,

            &hf_nhrp_flag_NAT,

            NULL

        };

        proto_tree_add_bitmask(nhrp_tree, tvb, offset, hf_nhrp_flags, ett_nhrp_mand_flag, flags, ENC_BIG_ENDIAN);

        offset += 2;

        col_append_fstr(pinfo->cinfo, COL_INFO, ", ID=%u", tvb_get_ntohl(tvb, offset));

        proto_tree_add_item(nhrp_tree, hf_nhrp_request_id, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

        }

        break;

    case NHRP_ERROR_INDICATION:

        {

        /* Skip unused field */

        offset += 2;

        col_append_fstr(pinfo->cinfo, COL_INFO, ", %s",

            val_to_str(tvb_get_ntohs(tvb, offset), nhrp_error_code_vals, "Unknown Error (%u)"));

        proto_tree_add_item(nhrp_tree, hf_nhrp_error_code, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        proto_tree_add_item(nhrp_tree, hf_nhrp_error_offset, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        }

        break;

    case NHRP_TRAFFIC_INDICATION:

        {

        /* Skip unused field */

        offset += 2;

        col_append_fstr(pinfo->cinfo, COL_INFO, ", %s",

            val_to_str(tvb_get_ntohs(tvb, offset), nhrp_traffic_code_vals, "Unknown traffic code (%u)"));

        proto_tree_add_item(nhrp_tree, hf_nhrp_traffic_code, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        /* Skip unused field */

        offset += 2;

        }

        break;

    default:

        /* Unknown packet type */

        offset += 6;

        break;

    }

    shl = NHRP_SHTL_LEN(hdr->ar_shtl);

    if (shl) {

        switch (hdr->ar_afn) {

        case AFNUM_INET:

            if (shl == 4)

                proto_tree_add_item(nhrp_tree, hf_nhrp_src_nbma_addr, tvb, offset, 4, ENC_BIG_ENDIAN);

            else {

                proto_tree_add_item(nhrp_tree, hf_nhrp_src_nbma_addr_bytes, tvb, offset, shl, ENC_NA);

            }

            break;

        default:

            proto_tree_add_item(nhrp_tree, hf_nhrp_src_nbma_addr_bytes, tvb, offset, shl, ENC_NA);

            break;

        }

        offset += shl;

    }

    ssl = NHRP_SHTL_LEN(hdr->ar_sstl);

    if (ssl) {

        proto_tree_add_item(nhrp_tree, hf_nhrp_src_nbma_saddr, tvb, offset, ssl, ENC_NA);

        offset += ssl;

    }

    if (*srcLen == 4) {

        proto_tree_add_item(nhrp_tree, hf_nhrp_src_prot_addr, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

    }

    else if (*srcLen) {

        proto_tree_add_item(nhrp_tree, hf_nhrp_src_prot_addr_bytes, tvb, offset, *srcLen, ENC_NA);

        offset += *srcLen;

    }

    if (dstLen == 4) {

        proto_tree_add_item(nhrp_tree, hf_nhrp_dst_prot_addr, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

    }

    else if (dstLen) {

        proto_tree_add_item(nhrp_tree, hf_nhrp_dst_prot_addr_bytes, tvb, offset, dstLen, ENC_NA);

        offset += dstLen;

    }

    /*

     * CIE list in most packet types, NHRP packet in error in Error

     * Indication, data packet in Traffic Indication.

     */

    switch (hdr->ar_op_type)

    {

    case NHRP_RESOLUTION_REQ:

    case NHRP_REGISTRATION_REQ:

    case NHRP_PURGE_REQ:

        dissect_cie_list(tvb, pinfo, nhrp_tree, offset, mandEnd, hdr, true, codeinfo);

        break;

    case NHRP_RESOLUTION_REPLY:

    case NHRP_REGISTRATION_REPLY:

    case NHRP_PURGE_REPLY:

        dissect_cie_list(tvb, pinfo, nhrp_tree, offset, mandEnd, hdr, false, codeinfo);

        break;

    case NHRP_ERROR_INDICATION:

        ind_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_nhrp_indication, &ind_item, "Packet Causing Indication");

        save_in_error_pkt = pinfo->flags.in_error_pkt;

        pinfo->flags.in_error_pkt = true;

        sub_tvb = tvb_new_subset_remaining(tvb, offset);

        // We recurse here, but we'll run out of packet before we run out of stack.

        _dissect_nhrp(sub_tvb, pinfo, ind_tree, true, false);

        pinfo->flags.in_error_pkt = save_in_error_pkt;

        break;

    case NHRP_TRAFFIC_INDICATION:

        ind_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_nhrp_indication, &ind_item, "Packet Causing Indication");

        save_in_error_pkt = pinfo->flags.in_error_pkt;

        pinfo->flags.in_error_pkt = true;

        sub_tvb = tvb_new_subset_remaining(tvb, offset);

        if (hdr->ar_pro_type <= 0xFF) {

            /* It's an NLPID */

            if (hdr->ar_pro_type == NLPID_SNAP) {

                /*

                 * Dissect based on the SNAP OUI and PID.

                 */

                if (hdr->ar_pro_type_oui == 0x000000) {

                    /*

                     * "Should not happen", as the protocol type should

                     * be the Ethertype, but....

                     */

                    dissected = dissector_try_uint(

                        ethertype_subdissector_table,

                        hdr->ar_pro_type_pid,

                        sub_tvb, pinfo, ind_tree);

                } else {

                    /*

                     * If we have a dissector table, use it, otherwise

                     * just dissect as data.

                     */

                    if (oui_info != NULL) {

                        dissected = dissector_try_uint(

                            oui_info->table,

                            hdr->ar_pro_type_pid,

                            sub_tvb, pinfo,

                            ind_tree);

                    } else

                        dissected = 0;

                }

            } else {

                /*

                 * Dissect based on the NLPID.

                 */

                dissected = dissector_try_uint(

                    osinl_incl_subdissector_table,

                    hdr->ar_pro_type, sub_tvb, pinfo,

                    ind_tree) ||

                            dissector_try_uint(

                    osinl_excl_subdissector_table,

                    hdr->ar_pro_type, sub_tvb, pinfo,

                    ind_tree);

            }

        } else if (hdr->ar_pro_type <= 0x3FF) {

            /* Reserved for future use by the IETF */

            dissected = 0;

        } else if (hdr->ar_pro_type <= 0x04FF) {

            /* Allocated for use by the ATM Forum */

            dissected = 0;

        } else if (hdr->ar_pro_type <= 0x05FF) {

            /* Experimental/Local use */

            dissected = 0;

        } else {

            dissected = dissector_try_uint(

                ethertype_subdissector_table,

                hdr->ar_pro_type, sub_tvb, pinfo, ind_tree);

        }

        if (!dissected) {

            call_data_dissector(sub_tvb, pinfo, ind_tree);

        }

        pinfo->flags.in_error_pkt = save_in_error_pkt;

        break;

    default:

        break;

    }

}

static void dissect_nhrp_ext(tvbuff_t    *tvb,

                      packet_info *pinfo,

                      proto_tree  *tree,

                      int         *pOffset,

                      int          extLen,

                      e_nhrp_hdr  *hdr,

                      unsigned     srcLen,

                      bool         nested)

{

    int offset = *pOffset;

    int extEnd = offset + extLen;

    while ((offset + 4) <= extEnd)

    {

        proto_tree *nhrp_tree;

        proto_item *nhrp_item;

        int         extTypeC = tvb_get_ntohs(tvb, offset);

        int         extType  = extTypeC & 0x3FFF;

        unsigned    len      = tvb_get_ntohs(tvb, offset+2);

        if ((extType == NHRP_EXT_NAT_ADDRESS) && (len == 8)) {

            /* Assume it's not really a Cisco NAT extension, but a device

             * capabilities extension instead (see RFC 2735). */

            nhrp_tree =  proto_tree_add_subtree(tree, tvb, offset,

                -1, ett_nhrp_ext, &nhrp_item, "Device Capabilities Extension");

        }

        else {

            nhrp_tree =  proto_tree_add_subtree(tree, tvb, offset,

                -1, ett_nhrp_ext, &nhrp_item,

                val_to_str(extType, ext_type_vals, "Unknown (%u)"));

        }

        proto_tree_add_boolean(nhrp_tree, hf_nhrp_ext_C, tvb, offset, 2, extTypeC);

        proto_tree_add_item(nhrp_tree, hf_nhrp_ext_type, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        proto_tree_add_item(nhrp_tree, hf_nhrp_ext_len, tvb, offset, 2, ENC_BIG_ENDIAN);

        offset += 2;

        if (len && (extType != NHRP_EXT_NULL)) {

            if ((extType == NHRP_EXT_NAT_ADDRESS) && (len == 8)) {

                /* Assume it's not really a Cisco NAT extension, but a device

                 * capabilities extension instead (see RFC 2735). */

                proto_tree *devcap_tree;

                proto_item *cap_item;

                proto_tree *cap_tree;

                devcap_tree = proto_tree_add_subtree_format(nhrp_tree, tvb, offset, len,

                    ett_nhrp_devcap_ext, NULL, "Extension Data: Src is %sVPN-aware; Dst is %sVPN-aware",

                    tvb_get_ntohl(tvb, offset) & 1 ? "" : "non-",

                    tvb_get_ntohl(tvb, offset + 4) & 1 ? "" : "non-");

                cap_item = proto_tree_add_item(devcap_tree, hf_nhrp_devcap_ext_srccap, tvb, offset, 4, ENC_BIG_ENDIAN);

                cap_tree = proto_item_add_subtree(cap_item, ett_nhrp_devcap_ext_srccap);

                proto_tree_add_item(cap_tree, hf_nhrp_devcap_ext_srccap_V, tvb, offset, 4, ENC_BIG_ENDIAN);

                cap_item = proto_tree_add_item(devcap_tree, hf_nhrp_devcap_ext_dstcap, tvb, offset + 4, 4, ENC_BIG_ENDIAN);

                cap_tree = proto_item_add_subtree(cap_item, ett_nhrp_devcap_ext_dstcap);

                proto_tree_add_item(cap_tree, hf_nhrp_devcap_ext_dstcap_V, tvb, offset + 4, 4, ENC_BIG_ENDIAN);

                goto skip_switch;

            }

            switch (extType) {

            case NHRP_EXT_RESP_ADDR:

            case NHRP_EXT_FWD_RECORD:

            case NHRP_EXT_REV_RECORD:

            case NHRP_EXT_NAT_ADDRESS:

                dissect_cie_list(tvb, pinfo, nhrp_tree,

                    offset, offset + len, hdr, 0, false);

                break;

            case NHRP_EXT_AUTH:

                /* This is ugly, but this is the only place srcLen is actually

                 * used so we manipulate it here.

                 */

                if (!pref_auth_ext_has_addr)

                    srcLen = 0;

                /* fallthrough */

            case NHRP_EXT_MOBILE_AUTH:

                if (len < (4 + srcLen)) {

                    proto_tree_add_expert_format(nhrp_tree, pinfo, &ei_nhrp_ext_malformed, tvb, offset, len,

                        "Incomplete Authentication Extension");

                }

                else {

                    proto_tree *auth_tree;

                    proto_item *auth_item;

                    uint32_t spi;

                    auth_tree = proto_tree_add_subtree_format(nhrp_tree, tvb, offset, -1,

                        ett_nhrp_auth_ext, &auth_item, "Extension Data");

                    proto_tree_add_item(auth_tree, hf_nhrp_auth_ext_reserved, tvb, offset, 2, ENC_BIG_ENDIAN);

                    proto_tree_add_item_ret_uint(auth_tree, hf_nhrp_auth_ext_spi, tvb, offset + 2, 2, ENC_BIG_ENDIAN, &spi);

                    proto_item_append_text(auth_item, ": SPI=%u", spi);

                    if (srcLen == 4)

                        proto_tree_add_item(auth_tree, hf_nhrp_auth_ext_src_addr, tvb, offset + 4, 4, ENC_BIG_ENDIAN);

                    else if (srcLen) {

                        proto_tree_add_item(auth_tree, hf_nhrp_auth_ext_src_addr_bytes, tvb, offset + 4, srcLen, ENC_NA);

                    }

                    if (len > (4 + srcLen)) {

                        proto_tree_add_item(auth_tree, hf_nhrp_auth_data, tvb, offset + 4 + srcLen, len - (4 + srcLen), ENC_NA);

                        proto_item_append_text(auth_item, ": Data=%s",

                            tvb_bytes_to_str(pinfo->pool, tvb, offset + 4 + srcLen, len - (4 + srcLen)));

                    }

                    proto_item_set_len(auth_item, len);

                }

                break;

            case NHRP_EXT_VENDOR_PRIV:

                if (len < 3) {

                    proto_tree_add_expert_format(nhrp_tree, pinfo, &ei_nhrp_ext_malformed, tvb, offset, len,

                        "Incomplete Vendor-Private Extension");

                }

                else {

                    proto_tree *vendor_tree;

                    proto_item *vendor_item;

                    uint32_t manuf;

                    const char* oui;

                    vendor_tree = proto_tree_add_subtree(nhrp_tree, tvb, offset, len,

                        ett_nhrp_vendor_ext, &vendor_item, "Extension Data:");

                    proto_tree_add_item_ret_uint(vendor_tree, hf_nhrp_vendor_ext_id, tvb, offset, 3, ENC_BIG_ENDIAN, &manuf);

                    oui = uint_get_manuf_name_if_known(manuf);

                    if (oui != NULL) {

                        proto_item_append_text(vendor_item, " Vendor ID=%s", oui);

                    } else {

                        proto_item_append_text(vendor_item, " Vendor ID=Unknown");

                    }

                    if (len > 3) {

                        proto_tree_add_item(vendor_tree, hf_nhrp_vendor_ext_data, tvb, offset + 3, len - 3, ENC_NA);

                        proto_item_append_text(vendor_item, ", Data=%s", tvb_bytes_to_str(pinfo->pool, tvb, offset + 3, len - 3));

                    } else {

                        proto_item_append_text(vendor_item, ", Data=<none>");

                    }

                }

                break;

            default:

                proto_tree_add_item(nhrp_tree, hf_nhrp_unknown_ext_value, tvb,

                    offset, len, ENC_NA);

                break;

            }

skip_switch:

            offset += len;

        }

        proto_item_set_end(nhrp_item, tvb, offset);

        if (!nested) {

            len = tvb_reported_length_remaining(tvb, offset);

            if ((extType == NHRP_EXT_NULL) && len) {

                proto_tree_add_expert_format(tree, pinfo, &ei_nhrp_ext_extra, tvb, offset, len,

                    "Unknown Data (%d bytes)", len);

                break;

            }

        }

    }

    *pOffset = extEnd;

}

static int dissect_nhrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

    _dissect_nhrp(tvb, pinfo, tree, false, true);

    return tvb_captured_length(tvb);

}

// NOLINTNEXTLINE(misc-no-recursion)

static void _dissect_nhrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,

    bool nested, bool codeinfo)

{

    e_nhrp_hdr  hdr;

    int         mandLen  = 0;

    int         extLen   = 0;

    int         offset   = 0;

    proto_item *ti;

    proto_tree *nhrp_tree;

    oui_info_t *oui_info = NULL;

    unsigned    srcLen   = 0;

    if (!nested) {

        col_set_str(pinfo->cinfo, COL_PROTOCOL, "NHRP");

        col_clear(pinfo->cinfo, COL_INFO);

    }

    memset(&hdr, 0, sizeof(e_nhrp_hdr));

    hdr.ar_op_type = tvb_get_uint8(tvb, 17);

    if (!nested) {

        col_add_str(pinfo->cinfo, COL_INFO,

            val_to_str(hdr.ar_op_type, nhrp_op_type_vals,

                "0x%02X - unknown"));