path: root/epan/dissectors/packet-msdp.c

/* packet-msdp.c
 * Routines for Multicast Source Discovery Protocol (MSDP) dissection.
 * RFC 3618
 *
 * Copyright 2001, Heikki Vatiainen <hessu@cs.tut.fi>
 *
 * 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/to_str.h>
#include <epan/expert.h>

void proto_register_msdp(void);
void proto_reg_handoff_msdp(void);

/* MSDP (Type-Length-Value) TLV types. The messages are a sequence of TLVs. */
enum { MSDP_SA     = 1,
       MSDP_SA_REQ,
       MSDP_SA_RSP,
       MSDP_KEEP_ALIVE,
       MSDP_NOTIFICATION,  /* draft 10, but not RFC 3618 */

       /* These are only assigned in MSDP spec. Their use is specified
        * elsewhere */
       MSDP_TRACE_IN_PROGRESS,
       MSDP_TRACE_REPLY
};

static const value_string msdp_types[] = {
        { MSDP_SA,                "IPv4 Source-Active"           },
        { MSDP_SA_REQ,            "IPv4 Source-Active Request"   },
        { MSDP_SA_RSP,            "IPv4 Source-Active Response"  },
        { MSDP_KEEP_ALIVE,        "KeepAlive"                    },
        { MSDP_NOTIFICATION,      "Notification"                 },

        { MSDP_TRACE_IN_PROGRESS, "MSDP traceroute in progress"  },
        { MSDP_TRACE_REPLY,       "MSDP traceroute reply"        },
        { 0, NULL },
};


/* Error codes */
enum { MESSAGE_HEADER_ERROR = 1,
       SA_REQUEST_ERROR,
       SA_MESSAGE_SA_RESPONSE_ERROR,
       HOLD_TIMER_EXPIRED,
       FSM_ERROR,
       NOTIFICATION,
       CEASE
};

static const value_string error_vals[] = {
        { MESSAGE_HEADER_ERROR,         "Message Header Error"         },
        { SA_REQUEST_ERROR,             "SA-Request Error"             },
        { SA_MESSAGE_SA_RESPONSE_ERROR, "SA-Message/SA-Response Error" },
        { HOLD_TIMER_EXPIRED,           "Hold Timer Expired"           },
        { FSM_ERROR,                    "Finite State Machine Error"   },
        { NOTIFICATION,                 "Notification"                 },
        { CEASE,                        "Cease"                        },
        { 0, NULL },
};


/* Message Header Error subcodes */
static const value_string hdr_error_vals[] = {
        { 0, "Unspecific"         },
        { 2, "Bad Message Length" },
        { 3, "Bad Message Type"   },
        { 0, NULL },
};

/* SA-Request Error subcodes (the O-bit is always clear) */
static const value_string sa_req_error_vals[] = {
        { 0, "Unspecific"    },
        { 1, "Invalid Group" },
        { 0, NULL },
};

/* SA-Message/SA-Response Error subcodes */
static const value_string sa_msg_error_vals[] = {
        { 0, "Unspecific"                             },
        { 1, "Invalid Entry Count"                    },
        { 2, "Invalid RP Address"                     },
        { 3, "Invalid Group Address"                  },
        { 4, "Invalid Source Address"                 },
        { 5, "Invalid Sprefix Length"                 },
        { 6, "Looping SA (Self is RP)"                },
        { 7, "Unknown Encapsulation"                  },
        { 8, "Administrative Scope Boundary Violated" },
        { 0, NULL },
};

/* Finite State Machine Error subcodes (the O-bit is always clear) */
static const value_string fsm_error_vals[] = {
        { 0, "Unspecific"                        },
        { 1, "Unexpected Message Type FSM Error" },
        { 0, NULL },
};

/*
 * Hold Timer Expired subcodes (the O-bit is always clear):
 * Notification subcodes (the O-bit is always clear):
 * Cease subcodes (the O-bit is always clear):
 *
 * These have only "Unspecific" specified.
 */
static const value_string sa_unspec_error_vals[] = {
        { 0, "Unspecific" },
        { 0, NULL },
};

#define MSDP_PORT  639

/* Initialize the protocol and registered fields */
static int proto_msdp = -1;
static int hf_msdp_type = -1;
static int hf_msdp_length = -1;

static int hf_msdp_sa_entry_count = -1;
static int hf_msdp_sa_rp_addr = -1;
static int hf_msdp_sa_reserved = -1;
static int hf_msdp_sa_sprefix_len = -1;
static int hf_msdp_sa_group_addr = -1;
static int hf_msdp_sa_src_addr = -1;

static int hf_msdp_sa_req_res = -1;
static int hf_msdp_sa_req_group = -1;

static int hf_msdp_not_o = -1;
static int hf_msdp_not_error = -1;
static int hf_msdp_not_error_sub = -1;

static int hf_msdp_not_group_address = -1;
static int hf_msdp_not_rp_address = -1;
static int hf_msdp_not_source_address = -1;
static int hf_msdp_not_res = -1;
static int hf_msdp_not_entry_count = -1;
static int hf_msdp_not_sprefix_len = -1;

static int hf_msdp_tlv_contents = -1;
static int hf_msdp_trailing_junk = -1;
static int hf_msdp_unknown_data = -1;

static gint ett_msdp = -1;
static gint ett_msdp_sa_entry = -1;
static gint ett_msdp_sa_enc_data = -1;
static gint ett_msdp_not_data = -1;

static expert_field ei_msdp_tlv_len_too_short = EI_INIT;
static expert_field ei_msdp_tlv_len_too_long = EI_INIT;

static dissector_handle_t ip_handle;


static void
dissect_msdp_sa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
    int *offset, int length, proto_item *length_item);
static void
dissect_msdp_notification(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
    int *offset, guint16 tlv_len, proto_item *length_item);


static int
dissect_msdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
        proto_item *ti;
        proto_tree *msdp_tree;
        proto_item *length_item;
        int         offset;
        guint32     type;
        guint32     length;


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

        col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(tvb_get_guint8(tvb, 0),
                                                                     msdp_types,
                                                                     "<Unknown MSDP TLV type>"));

        ti = proto_tree_add_item(tree, proto_msdp, tvb, 0, -1, ENC_NA);
        msdp_tree = proto_item_add_subtree(ti, ett_msdp);

        offset = 0;
        while (tvb_reported_length_remaining(tvb, offset) != 0) {
                proto_tree_add_item_ret_uint(msdp_tree, hf_msdp_type, tvb, offset, 1, ENC_BIG_ENDIAN, &type);
                length_item = proto_tree_add_item_ret_uint(msdp_tree, hf_msdp_length, tvb, offset + 1, 2, ENC_BIG_ENDIAN, &length);
                if (length < 3) {
                        expert_add_info_format(pinfo, length_item,
                            &ei_msdp_tlv_len_too_short,
                            "TLV length < 3");
                        break;
                }
                offset += 3;
                length -= 3;

                switch (type) {
                case MSDP_SA:
                        dissect_msdp_sa(tvb, pinfo, msdp_tree, &offset,
                                        length, length_item);
                        break;
                case MSDP_SA_REQ:
                        /*
                         * This type is mentioned in the RFC but the format
                         * isn't described.
                         */
                        if (length < 1) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for IPv4 Source-Active Request < 8");
                                break;
                        }
                        proto_tree_add_item(msdp_tree, hf_msdp_sa_req_res, tvb, offset, 1, ENC_BIG_ENDIAN);
                        offset += 1;
                        length -= 1;
                        if (length < 4) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for IPv4 Source-Active Request < 8");
                                offset += length;
                                break;
                        }
                        proto_tree_add_item(msdp_tree, hf_msdp_sa_req_group, tvb, offset, 4, ENC_BIG_ENDIAN);
                        offset += 4;
                        length -= 4;
                        if (length > 0) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_long,
                                    "TLV length for KeepAlive > 8");
                                proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, offset, length, ENC_NA);
                                offset += length;
                        }
                        break;
                case MSDP_SA_RSP:
                        /*
                         * This type is mentioned in the RFC but the format
                         * isn't described.
                         */
                        dissect_msdp_sa(tvb, pinfo, msdp_tree, &offset,
                                        length, length_item);
                        break;
                case MSDP_KEEP_ALIVE:
                        if (length > 0) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_long,
                                    "TLV length for KeepAlive > 3");
                                proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, offset, length, ENC_NA);
                                offset += length;
                        }
                        break;
                case MSDP_NOTIFICATION:
                        /*
                         * This was in draft 10, but is reserved in the
                         * RFC.
                         */
                        dissect_msdp_notification(tvb, pinfo, msdp_tree, &offset, length, length_item);
                        break;
                default:
                        if (length > 0)
                                proto_tree_add_item(msdp_tree, hf_msdp_tlv_contents, tvb, offset, length, ENC_NA);
                        offset += length;
                        break;
                }
        }

        return tvb_captured_length(tvb);
}

/* Both Source-Active and Source-Active Response have the same format
 * with one exception. Encapsulated multicast data is not allowed in
 * SA Response.
 */
static void dissect_msdp_sa(tvbuff_t *tvb, packet_info *pinfo,
    proto_tree *tree, int *offset, int length, proto_item *length_item)
{
        guint32 entries;

        if (length < 1) {
                expert_add_info_format(pinfo, length_item,
                    &ei_msdp_tlv_len_too_short,
                    "TLV length for IPv4 Source-Active or Source-Active Response < 5");
                return;
        }
        proto_tree_add_item_ret_uint(tree, hf_msdp_sa_entry_count, tvb, *offset, 1, ENC_BIG_ENDIAN, &entries);
        *offset += 1;
        length -= 1;

        if (length < 4) {
                expert_add_info_format(pinfo, length_item,
                    &ei_msdp_tlv_len_too_short,
                    "TLV length for IPv4 Source-Active or Source-Active Response < 5");
                *offset += length;
                return;
        }
        proto_tree_add_item(tree, hf_msdp_sa_rp_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
        *offset += 4;
        length -= 4;

        /* Put each of the (S,G) entries in their own subtree.
         * This is probably visually better.
         */
        while (entries-- > 0) {
                proto_tree *entry_tree;

                if (length < 12) {
                        expert_add_info_format(pinfo, length_item,
                            &ei_msdp_tlv_len_too_short,
                            "TLV length for IPv4 Source-Active or Source-Active Response too short");
                        *offset += length;
                        return;
                }
                entry_tree = proto_tree_add_subtree_format(tree, tvb, *offset, 12, ett_msdp_sa_entry, NULL,
                                         "(S,G) block: %s/%u -> %s",
                                         tvb_ip_to_str(tvb, *offset + 8),
                                         tvb_get_guint8(tvb, *offset + 3),
                                         tvb_ip_to_str(tvb, *offset + 4));

                proto_tree_add_item(entry_tree, hf_msdp_sa_reserved, tvb, *offset, 3, ENC_BIG_ENDIAN);
                *offset += 3;
                length -= 3;
                proto_tree_add_item(entry_tree, hf_msdp_sa_sprefix_len, tvb, *offset, 1, ENC_BIG_ENDIAN);
                *offset += 1;
                length -= 1;
                proto_tree_add_item(entry_tree, hf_msdp_sa_group_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
                *offset += 4;
                length -= 4;
                proto_tree_add_item(entry_tree, hf_msdp_sa_src_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
                *offset += 4;
                length -= 4;
        }

        /*
         * Check if an encapsulated multicast IPv4 packet follows
         */
        if (length > 0) {
                proto_tree *enc_tree;
                gint reported_length;
                tvbuff_t *next_tvb;

                enc_tree = proto_tree_add_subtree_format(tree, tvb, *offset, length,
                                         ett_msdp_sa_enc_data, NULL, "Encapsulated IPv4 packet: %u bytes",
                                         length);

                reported_length = tvb_reported_length_remaining(tvb, *offset);
                DISSECTOR_ASSERT(reported_length >= 0);
                if (reported_length > length)
                        reported_length = length;

                next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
                /* Set the protocol and information columns read-only so
                 * that they reflect the MSDP packet rather than the
                 * encapsulated packet.
                 */
                col_set_writable(pinfo->cinfo, COL_PROTOCOL, FALSE);
                col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
                call_dissector(ip_handle, next_tvb, pinfo, enc_tree);
        }
        *offset += length;

        return;
}

/* Note: updates *offset */
static void add_notification_data_ipv4addr(tvbuff_t *tvb, proto_tree *tree, int *offset, int hf_addr)
{
        proto_tree_add_item(tree, hf_msdp_not_res, tvb, *offset, 3, ENC_BIG_ENDIAN);
        *offset += 3;
        proto_tree_add_item(tree, hf_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
        *offset += 4;

        return;
}

static void dissect_msdp_notification(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int *offset, guint16 tlv_len, proto_item *length_item)
{
        guint8              error, error_sub;
        const value_string *vals;
        gint reported_length;
        tvbuff_t *next_tvb;

        if (tlv_len < 1) {
                expert_add_info_format(pinfo, length_item,
                    &ei_msdp_tlv_len_too_short,
                    "TLV length for Notification < 4");
                return;
        }
        proto_tree_add_item(tree, hf_msdp_not_o, tvb, *offset, 1, ENC_BIG_ENDIAN);
        proto_tree_add_item(tree, hf_msdp_not_error, tvb, *offset, 1, ENC_BIG_ENDIAN);
        error = tvb_get_guint8(tvb, *offset);
        error &= 0x7F;             /* Error is 7-bit field. O-bit is bit 8 */
        *offset += 1;
        tlv_len -= 1;

        /* Depending on the Error Code, we collect the correct
         * value_strings for the Error subcode
         */
        switch (error) {
        case MESSAGE_HEADER_ERROR:
                vals = hdr_error_vals;
                break;
        case SA_REQUEST_ERROR:
                vals = sa_req_error_vals;
                break;
        case SA_MESSAGE_SA_RESPONSE_ERROR:
                vals = sa_msg_error_vals;
                break;
        case FSM_ERROR:
                vals = fsm_error_vals;
                break;
        case HOLD_TIMER_EXPIRED:
        case NOTIFICATION:
        case CEASE:
                vals = sa_unspec_error_vals;
                break;
        default:
                vals = sa_unspec_error_vals;
                break;
        }

        if (tlv_len < 1) {
                expert_add_info_format(pinfo, length_item,
                    &ei_msdp_tlv_len_too_short,
                    "TLV length for Notification < 5");
                return;
        }
        error_sub = tvb_get_guint8(tvb, *offset);
        proto_tree_add_uint_format_value(tree, hf_msdp_not_error_sub, tvb, *offset, 1,
                                   error_sub, "%s (%u)",
                                   val_to_str_const(error_sub, vals, "<Unknown Error subcode>"),
                                   error_sub);
        *offset += 1;
        tlv_len -= 1;

        /* Do switch again, this time to dissect the data portion
         * correctly. Ugly.
         */
        switch (error) {
        case SA_REQUEST_ERROR:
                if (tlv_len < 7) {
                        expert_add_info_format(pinfo, length_item,
                            &ei_msdp_tlv_len_too_short,
                            "TLV length for Notification SA-Request Error < 12");
                        *offset += tlv_len;
                        return;
                }
                add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_group_address);
                tlv_len -= 7;
                break;
        case SA_MESSAGE_SA_RESPONSE_ERROR:
                if (error_sub == 0) {
                        break;
                } else if (error_sub == 1) {
                        if (tlv_len < 1) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for Notification SA-Response Invalid Entry Count Error < 6");
                                return;
                        }
                        proto_tree_add_item(tree, hf_msdp_not_entry_count, tvb, *offset, 1, ENC_BIG_ENDIAN);
                        *offset += 1;
                        tlv_len -= 1;
                        break;
                } else if (error_sub == 2) {
                        if (tlv_len < 7) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for Notification SA-Response Invalid RP Address Error < 12");
                                *offset += tlv_len;
                                return;
                        }
                        add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_rp_address);
                        tlv_len -= 7;
                        break;
                } else if (error_sub == 3 || error_sub == 8) {
                        if (tlv_len < 7) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for Notification SA-Response %s Error < 12",
                                    (error_sub == 3) ? "Invalid Group Address"
                                                     : "Administrative Scope Boundary Violated");
                                *offset += tlv_len;
                                return;
                        }
                        add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_group_address);
                        tlv_len -= 7;
                        break;
                } else if (error_sub == 4) {
                        if (tlv_len < 7) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for Notification SA-Response Invalid Source Address Error < 12");
                                *offset += tlv_len;
                                return;
                        }
                        add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_source_address);
                        tlv_len -= 7;
                        break;
                } else if (error_sub == 5) {
                        if (tlv_len < 1) {
                                expert_add_info_format(pinfo, length_item,
                                    &ei_msdp_tlv_len_too_short,
                                    "TLV length for Notification SA-Response Invalid Invalid Sprefix Length Error < 6");
                                return;
                        }
                        proto_tree_add_item(tree, hf_msdp_not_sprefix_len, tvb, *offset, 1, ENC_BIG_ENDIAN);
                        *offset += 1;
                        tlv_len -= 1;
                        break;
                } else if (error_sub == 6) {
                        if (tlv_len > 0) {
                                reported_length = tvb_reported_length_remaining(tvb, *offset);
                                DISSECTOR_ASSERT(reported_length >= 0);
                                if (reported_length > tlv_len)
                                        reported_length = tlv_len;
                                next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
                                dissect_msdp(next_tvb, pinfo, tree, NULL);
                        }
                        *offset += tlv_len;
                        tlv_len = 0;
                } else if (error_sub == 7) {
                        if (tlv_len > 0) {
                                reported_length = tvb_reported_length_remaining(tvb, *offset);
                                DISSECTOR_ASSERT(reported_length >= 0);
                                if (reported_length > tlv_len)
                                        reported_length = tlv_len;
                                next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
                                dissect_msdp(next_tvb, pinfo, tree, NULL);
                        }
                        *offset += tlv_len;
                        tlv_len = 0;
                        break;
                } else {
                        if (tlv_len > 0)
                                proto_tree_add_item(tree, hf_msdp_unknown_data, tvb, *offset, tlv_len, ENC_NA);
                        *offset += tlv_len;
                        tlv_len = 0;
                        break;
                }
                break;
        case MESSAGE_HEADER_ERROR:
        case NOTIFICATION:
                /* Data contains the message that had an error. Even a
                 * broken Notification message causes a Notification
                 * message with Error Code set to Notification to be
                 * sent back.
                 */
                if (tlv_len > 0) {
                        reported_length = tvb_reported_length_remaining(tvb, *offset);
                        DISSECTOR_ASSERT(reported_length >= 0);
                        if (reported_length > tlv_len)
                                reported_length = tlv_len;
                        next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
                        dissect_msdp(next_tvb, pinfo, tree, NULL);
                }
                *offset += tlv_len;
                tlv_len = 0;
                break;
        case FSM_ERROR:
        case HOLD_TIMER_EXPIRED:
        case CEASE:
                /* Do nothing. These contain no data */
                break;
        default:
                if (tlv_len > 0)
                        proto_tree_add_item(tree, hf_msdp_unknown_data, tvb, *offset, tlv_len, ENC_NA);
                *offset += tlv_len;
                tlv_len = 0;
                break;
        }
        if (tlv_len != 0) {
                expert_add_info_format(pinfo, length_item,
                    &ei_msdp_tlv_len_too_long,
                    "TLV length too long");
                proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, *offset, tlv_len, ENC_NA);
                *offset += tlv_len;
        }

        return;
}

void
proto_register_msdp(void)
{
        static hf_register_info hf[] = {
                { &hf_msdp_type,
                        { "Type",           "msdp.type",
                        FT_UINT8, BASE_DEC, VALS(msdp_types), 0,
                        "MSDP TLV type", HFILL }
                },
                { &hf_msdp_length,
                        { "Length",           "msdp.length",
                        FT_UINT16, BASE_DEC, NULL, 0,
                        "MSDP TLV Length", HFILL }
                },
                { &hf_msdp_sa_entry_count,
                        { "Entry Count",           "msdp.sa.entry_count",
                        FT_UINT8, BASE_DEC, NULL, 0,
                        "MSDP SA Entry Count", HFILL }
                },
                { &hf_msdp_sa_rp_addr,
                        { "RP Address",           "msdp.sa.rp_addr",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "Active source's RP address", HFILL }
                },
                { &hf_msdp_sa_reserved,
                        { "Reserved",           "msdp.sa.reserved",
                        FT_UINT24, BASE_HEX, NULL, 0,
                        "Transmitted as zeros and ignored by a receiver", HFILL }
                },
                { &hf_msdp_sa_sprefix_len,
                        { "Sprefix len",           "msdp.sa.sprefix_len",
                        FT_UINT8, BASE_DEC, NULL, 0,
                        "The route prefix length associated with source address", HFILL }
                },
                { &hf_msdp_sa_group_addr,
                        { "Group Address",           "msdp.sa.group_addr",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "The group address the active source has sent data to", HFILL }
                },
                { &hf_msdp_sa_src_addr,
                        { "Source Address",           "msdp.sa.src_addr",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "The IP address of the active source", HFILL }
                },
                { &hf_msdp_sa_req_res,
                        { "Reserved",           "msdp.sa_req.res",
                        FT_UINT8, BASE_HEX, NULL, 0,
                        "Transmitted as zeros and ignored by a receiver", HFILL }
                },
                { &hf_msdp_sa_req_group,
                        { "Group Address",           "msdp.sa_req.group_addr",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "The group address the MSDP peer is requesting", HFILL }
                },
                { &hf_msdp_not_o,
                        { "Open-bit",           "msdp.not.o",
                        FT_UINT8, BASE_HEX, NULL, 0x80,
                        "If clear, the connection will be closed", HFILL }
                },
                { &hf_msdp_not_error,
                        { "Error Code",           "msdp.not.error",
                        FT_UINT8, BASE_DEC, VALS(error_vals), 0x7F,
                        "Indicates the type of Notification", HFILL }
                },
                { &hf_msdp_not_error_sub,
                        { "Error subcode",           "msdp.not.error_sub",
                        FT_UINT8, BASE_DEC, NULL, 0,
                        NULL, HFILL }
                },
                { &hf_msdp_not_group_address,
                        { "Group address",           "msdp.not.group_address",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "Group address in Notification messages", HFILL }
                },
                { &hf_msdp_not_rp_address,
                        { "RP address",           "msdp.not.rp_address",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "RP address in Notification messages", HFILL }
                },
                { &hf_msdp_not_source_address,
                        { "Source address",           "msdp.not.source_address",
                        FT_IPv4, BASE_NONE, NULL, 0,
                        "Source address in Notification messages", HFILL }
                },
                { &hf_msdp_not_res,
                        { "Reserved",           "msdp.not.res",
                        FT_UINT24, BASE_HEX, NULL, 0,
                        "Reserved field in Notification messages", HFILL }
                },
                { &hf_msdp_not_entry_count,
                        { "Entry Count",           "msdp.not.entry_count",
                        FT_UINT24, BASE_HEX, NULL, 0,
                        "Entry Count in Notification messages", HFILL }
                },
                { &hf_msdp_not_sprefix_len,
                        { "Sprefix len",           "msdp.not.sprefix_len",
                        FT_UINT8, BASE_DEC, NULL, 0,
                        "Source prefix length in Notification messages", HFILL }
                },
                { &hf_msdp_tlv_contents,
                        { "TLV contents",           "msdp.tlv_contents",
                        FT_BYTES, BASE_NONE, NULL, 0,
                        NULL, HFILL }
                },
                { &hf_msdp_trailing_junk,
                        { "Trailing junk",           "msdp.trailing_junk",
                        FT_BYTES, BASE_NONE, NULL, 0,
                        NULL, HFILL }
                },
                { &hf_msdp_unknown_data,
                        { "Unknown data",           "msdp.unknown_data",
                        FT_BYTES, BASE_NONE, NULL, 0,
                        NULL, HFILL }
                },
        };

        static gint *ett[] = {
                &ett_msdp,
                &ett_msdp_sa_entry,
                &ett_msdp_sa_enc_data,
                &ett_msdp_not_data,
        };

        static ei_register_info ei[] = {
                { &ei_msdp_tlv_len_too_long,
                    { "msdp.tlv_len.too_long", PI_PROTOCOL, PI_WARN,
                      "TLV length too long", EXPFILL }
                },
                { &ei_msdp_tlv_len_too_short,
                    { "msdp.tlv_len.too_short", PI_MALFORMED, PI_ERROR,
                      "TLV length too short", EXPFILL }
                },
        };

        expert_module_t *expert_msdp;

        proto_msdp = proto_register_protocol("Multicast Source Discovery Protocol",
            "MSDP", "msdp");

        proto_register_field_array(proto_msdp, hf, array_length(hf));
        proto_register_subtree_array(ett, array_length(ett));
        expert_msdp = expert_register_protocol(proto_msdp);
        expert_register_field_array(expert_msdp, ei, array_length(ei));
}

void
proto_reg_handoff_msdp(void)
{
        dissector_handle_t msdp_handle;

        msdp_handle = create_dissector_handle(dissect_msdp, proto_msdp);
        dissector_add_uint_with_preference("tcp.port", MSDP_PORT, msdp_handle);

        ip_handle = find_dissector_add_dependency("ip", proto_msdp);
}

/*
 * Editor modelines
 *
 * Local Variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set shiftwidth=8 tabstop=8 expandtab:
 * :indentSize=8:tabSize=8:noTabs=true:
 */