/* packet-ripng.c

 * Routines for RIPng disassembly

 * (c) Copyright Jun-ichiro itojun Hagino <itojun@itojun.org>

 * derived from packet-rip.c

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * Enhance RIPng by Alexis La Goutte

 *

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

 *

 * References:

 * RFC2080: RIPng for IPv6

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/to_str.h>

void proto_register_ripng(void);

void proto_reg_handoff_ripng(void);

static dissector_handle_t ripng_handle;

static int proto_ripng;

static int hf_ripng_cmd;

static int hf_ripng_version;

static int hf_ripng_reserved;

static int hf_ripng_rte;

static int hf_ripng_rte_ipv6_prefix;

static int hf_ripng_rte_route_tag;

static int hf_ripng_rte_prefix_length;

static int hf_ripng_rte_metric;

static int ett_ripng;

static int ett_ripng_rte;

#define UDP_PORT_RIPNG  521

#define RIP6_REQUEST    1

#define RIP6_RESPONSE   2

static const value_string cmdvals[] = {

    { RIP6_REQUEST,  "Request" },

    { RIP6_RESPONSE, "Response" },

    { 0, NULL },

};

static int

dissect_ripng(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {

    unsigned offset = 0;

    proto_tree *ripng_tree = NULL, *rte_tree = NULL;

    proto_item *ti, *rte_ti;

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

    col_add_fstr(pinfo->cinfo, COL_INFO," Command %s, Version %u",

                 val_to_str(pinfo->pool, tvb_get_uint8(tvb, offset), cmdvals, "Unknown (%u)"),

                 tvb_get_uint8(tvb, offset +1));

    if (tree) {

        ti = proto_tree_add_item(tree, proto_ripng, tvb, offset, -1, ENC_NA);

        ripng_tree = proto_item_add_subtree(ti, ett_ripng);

        /* Command */

        proto_tree_add_item(ripng_tree, hf_ripng_cmd, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        /* Version */

        proto_tree_add_item(ripng_tree, hf_ripng_version, tvb, offset, 1, ENC_BIG_ENDIAN);

        offset += 1;

        /* Reserved */

        proto_tree_add_item(ripng_tree, hf_ripng_reserved, tvb, offset, 2, ENC_NA);

        offset += 2;

        /* Route Table Entry */

        while (tvb_reported_length_remaining(tvb, offset) > 0) {

            rte_ti = proto_tree_add_item(ripng_tree, hf_ripng_rte, tvb, offset, 16 + 2 + 1 + 1, ENC_NA);

            rte_tree = proto_item_add_subtree(rte_ti, ett_ripng_rte);

            /* IPv6 Prefix */

            proto_tree_add_item(rte_tree, hf_ripng_rte_ipv6_prefix, tvb, offset, 16, ENC_NA);

            proto_item_append_text(rte_ti, ": IPv6 Prefix: %s", tvb_ip6_to_str(pinfo->pool, tvb, offset));

            offset += 16;

            /* Route Tag */

            proto_tree_add_item(rte_tree, hf_ripng_rte_route_tag, tvb, offset, 2, ENC_BIG_ENDIAN);

            offset += 2;

            /* Prefix Length */

            proto_tree_add_item(rte_tree, hf_ripng_rte_prefix_length, tvb, offset, 1, ENC_BIG_ENDIAN);

            proto_item_append_text(rte_ti, "/%u", tvb_get_uint8(tvb, offset));

            offset += 1;

            /* Metric */

            proto_tree_add_item(rte_tree, hf_ripng_rte_metric, tvb, offset, 1, ENC_BIG_ENDIAN);

            proto_item_append_text(rte_ti, " Metric: %u", tvb_get_uint8(tvb, offset));

            offset += 1;

        }

    }

    return tvb_captured_length(tvb);

}

void

proto_register_ripng(void)

{

    static hf_register_info hf[] = {

        { &hf_ripng_cmd,

          { "Command",          "ripng.cmd",

            FT_UINT8, BASE_DEC, VALS(cmdvals), 0x0,

            "Used to specify the purpose of this message", HFILL }},

        { &hf_ripng_version,

          { "Version",          "ripng.version",

            FT_UINT8, BASE_DEC, NULL, 0x0,

            "Version of RIPng", HFILL }},

        { &hf_ripng_reserved,

          { "Reserved",         "ripng.reserved",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            "Must be Zero", HFILL }},

        { &hf_ripng_rte,

          { "Route Table Entry",                "ripng.rte",

            FT_NONE, BASE_NONE, NULL, 0x0,

            NULL, HFILL }},

        { &hf_ripng_rte_ipv6_prefix,

          { "IPv6 Prefix",              "ripng.rte.ipv6_prefix",

            FT_IPv6, BASE_NONE, NULL, 0x0,

            "Destination", HFILL }},

        { &hf_ripng_rte_route_tag,

          { "Route Tag",                "ripng.rte.route_tag",

            FT_UINT16, BASE_HEX, NULL, 0x0,

            "Provides a method of separating internal RIPng routes (routes for networks within the RIPng routing domain) from external RIPng routes, which may have been imported from an EGP or another IGP", HFILL }},

        { &hf_ripng_rte_prefix_length,

          { "Prefix Length",            "ripng.rte.prefix_length",

            FT_UINT8, BASE_DEC, NULL, 0x0,

            "The length in bits of the significant part of the prefix starting from the left of the prefix", HFILL }},

        { &hf_ripng_rte_metric,

          { "Metric",           "ripng.rte.metric",

            FT_UINT8, BASE_DEC, NULL, 0x0,

            "The current metric for the destination; the value 16 (infinity) indicates that the destination is not reachable", HFILL }},

    };

    static int *ett[] = {

        &ett_ripng,

        &ett_ripng_rte,

    };

    proto_ripng = proto_register_protocol("RIPng", "RIPng", "ripng");

    proto_register_field_array(proto_ripng, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

    ripng_handle = register_dissector("ripng", dissect_ripng, proto_ripng);

}

void

proto_reg_handoff_ripng(void)

{

    dissector_add_uint_with_preference("udp.port", UDP_PORT_RIPNG, ripng_handle);

}

/*

 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html

 *

 * Local variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * vi: set shiftwidth=4 tabstop=8 expandtab:

 * :indentSize=4:tabSize=8:noTabs=true:

 */