path: root/epan/dissectors/packet-cisco-sm.c

/* packet-sm.c
 * Routines for Cisco Session Management Protocol dissection
 * Copyright 2004, Duncan Sargeant <dunc-ethereal@rcpt.to>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

/*
 * This is basically a glue dissector for the Cisco SM protocol.  It sits
 * between the RUDP and MTP3 layers between SLTs and MGCs.
 *
 * A link to an overview of the technology :
 * http://www.cisco.com/en/US/products/sw/netmgtsw/ps4883/products_installation_and_configuration_guide_chapter09186a008010950a.html
 * Link showing debugs of the protocol:
 * http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/omts/omts_apb.htm#30052
 * Scroll down to Backhaul Debug Event/Cause/Reason Codes:
 * http://www.cisco.com/en/US/docs/ios-xml/ios/debug/command/s1/db-s2.html#GUID-83B6671D-B86F-4B41-819C-85D14F4AACAE
 * Free/Opensource implementation:
 * http://yate.null.ro/websvn/filedetails.php?repname=yate&path=%2Ftrunk%2Fmodules%2Fserver%2Fciscosm.cpp
 */

#include "config.h"

#include <epan/packet.h>

#define MESSAGE_TYPE_START              0
#define MESSAGE_TYPE_STOP               1
#define MESSAGE_TYPE_ACTIVE             2
#define MESSAGE_TYPE_STANDBY            3
#define MESSAGE_TYPE_Q_HOLD_INVOKE      4
#define MESSAGE_TYPE_Q_HOLD_RESPONSE    5
#define MESSAGE_TYPE_Q_RESUME_INVOKE    6
#define MESSAGE_TYPE_Q_RESUME_RESPONSE  7
#define MESSAGE_TYPE_Q_RESET_INVOKE     8
#define MESSAGE_TYPE_Q_RESET_RESPONSE   9
#define MESSAGE_TYPE_PDU                0x8000

void proto_register_sm(void);
void proto_reg_handoff_sm(void);

static const value_string sm_message_type_value[] = {
    { MESSAGE_TYPE_START,             "Start Message" },
    { MESSAGE_TYPE_STOP,              "Stop Message" },
    { MESSAGE_TYPE_ACTIVE,            "Active Message" },
    { MESSAGE_TYPE_STANDBY,           "Standby Message" },
    { MESSAGE_TYPE_Q_HOLD_INVOKE,     "Q_HOLD Invoke Message" },
    { MESSAGE_TYPE_Q_HOLD_RESPONSE,   "Q_HOLD Response Message" },
    { MESSAGE_TYPE_Q_RESUME_INVOKE,   "Q_RESUME Invoke Message" },
    { MESSAGE_TYPE_Q_RESUME_RESPONSE, "Q_RESUME Response Message" },
    { MESSAGE_TYPE_Q_RESET_INVOKE,    "Q_RESET Invoke Message" },
    { MESSAGE_TYPE_Q_RESET_RESPONSE,  "Q_RESET Response Message" },
    { MESSAGE_TYPE_PDU,               "PDU Message" },
    { 0, NULL }
};

static const value_string sm_message_type_value_info[] = {
    { MESSAGE_TYPE_START,             "Start" },
    { MESSAGE_TYPE_STOP,              "Stop" },
    { MESSAGE_TYPE_ACTIVE,            "Active" },
    { MESSAGE_TYPE_STANDBY,           "Standby" },
    { MESSAGE_TYPE_Q_HOLD_INVOKE,     "Q_HOLD Invoke" },
    { MESSAGE_TYPE_Q_HOLD_RESPONSE,   "Q_HOLD Response" },
    { MESSAGE_TYPE_Q_RESUME_INVOKE,   "Q_RESUME Invoke" },
    { MESSAGE_TYPE_Q_RESUME_RESPONSE, "Q_RESUME Response" },
    { MESSAGE_TYPE_Q_RESET_INVOKE,    "Q_RESET Invoke" },
    { MESSAGE_TYPE_Q_RESET_RESPONSE,  "Q_RESET Response" },
    { MESSAGE_TYPE_PDU,               "PDU" },
    { 0, NULL }
};

static const value_string sm_alignment_type[] = {
    { 0x00, "Unknown (probably linkset was already up)"},
    { 0x03, "Emergency alignment"},
    { 0x04, "Normal alignment"},
    { 0x05, "Power On MTP2"},
    { 0x06, "Start MTP2"},
    { 0, NULL}
};

static const value_string sm_backhaul_reason_code[] = {
    { 0x00, "Layer management request"},
    { 0x01, "SUERM (Signal Unit Error Monitor) failure"},
    { 0x02, "Excessively long alignment period"},
    { 0x03, "T7 timer expired"},
    { 0x04, "Physical interface failure"},
    { 0x05, "Two or three invalid BSNs"},
    { 0x06, "Two or three invalid FIBs"},
    { 0x07, "LSSU (Link Status Signal Unit) condition"},
    { 0x13, "SIOs (Service Information Octets) received "
            "in Link State Control (LSC)"},
    { 0x14, "Timer T2 expired waiting for SIO"},
    { 0x15, "Timer T3 expired waiting for SIE/SIN "},
    { 0x16, "SIO received in initial alignment control (IAC)"},
    { 0x17, "Proving period failure"},
    { 0x18, "Timer T1 expired waiting for FISU (Fill-In Signal Unit)"},
    { 0x19, "SIN received in the in-service state"},
    { 0x20, "CTS lost"},
    { 0x25, "No resources"},
    {    0, NULL}
};

static const value_string sm_backhaul_event_code[] = {
    { 0x00, "Local processor outage"},
    { 0x01, "Local processor outage recovered"},
    { 0x02, "Entered a congested state"},
    { 0x03, "Exited a congested state"},
    { 0x04, "Physical layer up"},
    { 0x05, "Physical layer down"},
    { 0x06, "Protocol error"},
    { 0x07, "Link is aligned"},
    { 0x08, "Link alignment lost"},
    { 0x09, "Retransmit buffer full"},
    { 0x0a, "Retransmit buffer no longer full"},
    { 0x0b, "Negative acknowledgment"},
    { 0x0c, "Remote entered congestion"},
    { 0x0d, "Remote exited congestion"},
    { 0x0e, "Remote entered processor outage"},
    { 0x0f, "Remote exited processor outage"},
    {    0, NULL}
};

static const value_string sm_backhaul_cause_code[] = {
    { 0x00, "Unknown (default)"},
    { 0x01, "Management initiated"},
    { 0x02, "Abnormal BSN (backward sequence number)"},
    { 0x03, "Abnormal FIB (Forward Indicator Bit)"},
    { 0x04, "Congestion discard"},
    {    0, NULL}
};

static const value_string sm_linkdown_cause_code[] = {
    { 0x00, "Unknown (default)"},
    { 0x01, "Management initiated"},
    { 0x03, "Congestion ended"},
    {    0, NULL}
};

static const value_string sm_retrieval_type[] = {
    { 0x01, "Request for BSN"},
    { 0x02, "Request for MSUs"},
    { 0x03, "Request to drop MSUs"},
    {    0, NULL}
};

static const value_string sm_lsc_state_type[] = {
    { 0x00, "Set LPO"},
    { 0x01, "Clear LPO"},
    { 0x02, "Set Emergency"},
    { 0x03, "Clear Emergency"},
    { 0x04, "Clear Buffers"},
    { 0x05, "Clear Transmit Buffer"},
    { 0x06, "Clear ReTransmission Buffer"},
    { 0x07, "Clear Receive Buffer"},
    { 0x08, "Continue"},
    { 0x09, "Power On"},
    { 0x0a, "Start"},
    { 0x0b, "Stop"},
    {    0, NULL}
};

static const value_string sm_stat_request_type[] = {
    { 0x00, "Reset"},
    { 0x01, "Send & Reset"},
    { 0x02, "Send"},
    {    0, NULL}
};

#define PDU_CONNECT_REQUEST       0x06
#define PDU_CONNECT_CONFIRM       0x07
#define PDU_DISCONNECT_CONFIRM    0x0b
#define PDU_DISCONNECT_INDICATION 0x0c
#define PDU_MTP3_TO_SLT           0x10
#define PDU_MTP3_FROM_SLT         0x11
#define PDU_RETRIEVAL_REQUEST     0x12
#define PDU_RETRIEVAL_CONFIRM     0x13
#define PDU_LSC_REQUEST           0x20
#define PDU_LSC_CONFIRM           0x21
#define PDU_LSC_INDICATION        0x22
#define PDU_STAT_REQUEST          0x44

static const value_string sm_pdu_type_value[] = {
    { PDU_CONNECT_REQUEST,       "Connect Request"},
    { PDU_CONNECT_CONFIRM,       "Connect Confirm"},
    { 0x0a,                      "Disconnect Request"},
    { PDU_DISCONNECT_CONFIRM,    "Disconnect Confirm"},
    { PDU_DISCONNECT_INDICATION, "Disconnect Indication Message"},
    { PDU_MTP3_TO_SLT,           "MSU Request (message to MTP2 link)"},
    { PDU_MTP3_FROM_SLT,         "MSU Indication (message from MTP2 link)"},
    { PDU_RETRIEVAL_REQUEST,     "Retrieval Request"},
    { PDU_RETRIEVAL_CONFIRM,     "Retrieval Confirm"},
    { 0x14,                      "Retrieval Indication"},
    { 0x15,                      "Retrieval Message"},
    { PDU_LSC_REQUEST,           "Link State Controller Request"},
    { PDU_LSC_CONFIRM,           "Link State Controller Confirm"},
    { PDU_LSC_INDICATION,        "Link State Controller Indication"},
    { 0x40,                      "Configuration Request"},
    { 0x41,                      "Configuration Confirm"},
    { 0x42,                      "Status Request"},
    { 0x43,                      "Status Confirm"},
    { PDU_STAT_REQUEST,          "Statistic Request"},
    { 0x45,                      "Statistic Confirm"},
    { 0x46,                      "Control Request"},
    { 0x47,                      "Control Confirm"},
    { 0x50,                      "Flow Control Request"},
    { 0x51,                      "Flow Control Indication"},
    { 0,                    NULL }
};

/* TODO: Change to useful name once known */
#define SM_PROTOCOL_X004 0x0004 /* https://gitlab.com/wireshark/wireshark/-/issues/7188 */
/* RUDP/SM stack called BSM V1 (version 1 versus Version 0 used for SS7). */
#define SM_PROTOCOL_X100 0x0100
#define SM_PROTOCOL_X101 0x0101
#define SM_PROTOCOL_X114 0x0114
#define SM_PROTOCOL_X122 0x0122


/* Initialize the protocol and registered fields */
static int proto_sm;

static int hf_sm_sm_msg_type;
static int hf_sm_protocol;
static int hf_sm_msg_id;
static int hf_sm_msg_type;
static int hf_sm_channel;
static int hf_sm_bearer;
static int hf_sm_len;
static int hf_sm_ip_addr;
static int hf_sm_context;
static int hf_sm_eisup_msg_id;
static int hf_sm_tag;
static int hf_sm_alignment_type;
static int hf_sm_backhaul_reason_code;
static int hf_sm_backhaul_event_code;
static int hf_sm_backhaul_cause_code;
static int hf_sm_linkdown_cause_code;
static int hf_sm_retrieval_type;
static int hf_sm_lsc_state_type;
static int hf_sm_stat_request_type;
static int hf_sm_bsn_num;

/* Initialize the subtree pointers */
static int ett_sm;

static dissector_handle_t sdp_handle;
static dissector_handle_t mtp3_handle;
static dissector_handle_t q931_handle;

/* Code to actually dissect the packets */
static int
dissect_sm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
    proto_item *ti;
    proto_tree *sm_tree;
    tvbuff_t   *next_tvb      = NULL;
    uint32_t    sm_message_type;
    uint32_t    bh_event_code = 0;
    uint16_t    protocol;
    uint16_t    msg_type      = 0;
    uint16_t    length;
    uint16_t    tag;
    int         offset        = 0;

    sm_message_type = tvb_get_ntohl(tvb,offset);

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

    col_add_fstr(pinfo->cinfo, COL_INFO, "Cisco SM Packet (%s)",
        val_to_str_const(sm_message_type, sm_message_type_value_info,"reserved"));

    ti = proto_tree_add_item(tree, proto_sm, tvb, offset, -1, ENC_NA);
    sm_tree = proto_item_add_subtree(ti, ett_sm);

    proto_tree_add_uint_format_value(sm_tree, hf_sm_sm_msg_type, tvb, offset, 4, sm_message_type,
        "%s (0x%0x)", val_to_str_const(sm_message_type, sm_message_type_value, "reserved"), sm_message_type);

    offset = offset + 4;
    if (sm_message_type ==  MESSAGE_TYPE_PDU) {
        proto_tree_add_item(sm_tree, hf_sm_protocol, tvb, offset, 2, ENC_BIG_ENDIAN);
        protocol = tvb_get_ntohs(tvb,offset);
        offset = offset + 2;
        switch(protocol){
        /* start case RUDP BSM v.1  ---------------------------------------------------------- */
        case SM_PROTOCOL_X004:
            proto_tree_add_item(sm_tree, hf_sm_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset +2;
            msg_type = tvb_get_ntohs(tvb,offset);
            proto_tree_add_uint_format_value(sm_tree, hf_sm_msg_type, tvb, offset, 2, msg_type,
                "%s (0x%0x)", val_to_str_const(msg_type, sm_pdu_type_value, "reserved"),
                msg_type);
            msg_type = tvb_get_ntohs(tvb,offset);
            offset = offset + 2;
            proto_tree_add_item(sm_tree, hf_sm_channel, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset + 2;
            proto_tree_add_item(sm_tree, hf_sm_bearer, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset +2;
            proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
            length = tvb_get_ntohs(tvb,offset);
            offset = offset +2;
            proto_item_set_len(ti, 16);

            if (length > 0) {
                next_tvb = tvb_new_subset_length(tvb, offset, length);

                if ((msg_type == PDU_MTP3_TO_SLT || msg_type == PDU_MTP3_FROM_SLT)) {
                    call_dissector(q931_handle, next_tvb, pinfo, tree);
                } else {
                    call_data_dissector(next_tvb, pinfo, tree);
                }
            }

            break;
            /* end case RUDP BSM v.1 ---------------------------------------------------------- */

        case SM_PROTOCOL_X100:
        case SM_PROTOCOL_X122:
            /* Protocol 0x100/0x122 only contains a length and then an EISUP packet */
            proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
            length = tvb_get_ntohs(tvb,offset);
            offset = offset + 2;
            proto_item_set_len(ti, 8);

            /* This should be the EISUP dissector but we haven't got one
             * right now - so decode it as data for now ... */
            next_tvb = tvb_new_subset_length(tvb, offset, length);
            call_data_dissector(next_tvb, pinfo, sm_tree);

            break;
        case SM_PROTOCOL_X101:
            /* XXX Reverse enginered so this may not be correct!!!
             * EISUP - used between Cisco HSI and Cisco PGW devices,
             * uses RUDP with default port number 8003.
             * Protocol stack is RUDP->Cisco SM->SDP.
             * This implementation is PROPRIETARY
             */
            proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
            length = tvb_get_ntohs(tvb,offset);
            offset = offset + 2;
            proto_item_set_len(ti, length + offset);
            /* The next stuff seems to be IP addr */
            proto_tree_add_item(sm_tree, hf_sm_ip_addr, tvb, offset, 4, ENC_BIG_ENDIAN);
            offset = offset + 4;
            /* This part looks to be the same per session */
            proto_tree_add_item(sm_tree, hf_sm_context, tvb, offset, 4, ENC_BIG_ENDIAN);
            offset = offset +4;
            /* Some sort of message type? */
            proto_tree_add_item(sm_tree, hf_sm_eisup_msg_id, tvb, offset, 1, ENC_BIG_ENDIAN);
            offset = offset + 1;
            /* XXX Problem are tags 1 or two bytes???*/
            proto_tree_add_item(sm_tree, hf_sm_tag, tvb, offset, 2, ENC_BIG_ENDIAN);

            tag = tvb_get_ntohs(tvb,offset);
            offset = offset +2;
            if (tag== 0x01ac) {
                proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
                length = tvb_get_ntohs(tvb,offset);
                offset = offset +2;
                next_tvb = tvb_new_subset_length(tvb, offset, length);
                call_dissector(sdp_handle, next_tvb, pinfo, sm_tree);
                /*offset = offset+length;*/

            }
            /*return;*/
            break;
        case SM_PROTOCOL_X114:
            /* XXX Reverse enginered so this may not be correct!!! */
            proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
            length = tvb_get_ntohs(tvb,offset);
            offset = offset + 2;
            proto_item_set_len(ti, length + offset);
            /* The next stuff seems to be IP addr */
            proto_tree_add_item(sm_tree, hf_sm_ip_addr, tvb, offset, 4, ENC_BIG_ENDIAN);
            offset = offset + 4;
            proto_tree_add_item(sm_tree, hf_sm_context, tvb, offset, 4, ENC_BIG_ENDIAN);
            offset = offset +4;
            /* Some sort of message type? */
            proto_tree_add_item(sm_tree, hf_sm_eisup_msg_id, tvb, offset, 1, ENC_BIG_ENDIAN);
            offset = offset + 1;
            /* XXX Problem are tags 1 or two bytes???*/
            proto_tree_add_item(sm_tree, hf_sm_tag, tvb, offset, 2, ENC_BIG_ENDIAN);

            tag = tvb_get_ntohs(tvb,offset);
            offset = offset +2;
            if (tag== 0x01ac) {
                proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
                length = tvb_get_ntohs(tvb,offset);
                offset = offset +2;
                next_tvb = tvb_new_subset_length(tvb, offset, length);
                call_dissector(sdp_handle, next_tvb, pinfo, sm_tree);
                /*offset = offset+length;*/

            }
            break;
        default:
            proto_tree_add_item(sm_tree, hf_sm_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset +2;
            msg_type = tvb_get_ntohs(tvb,offset);
            proto_tree_add_uint_format_value(sm_tree, hf_sm_msg_type, tvb, offset, 2, msg_type,
                "%s (0x%0x)", val_to_str_const(msg_type, sm_pdu_type_value, "reserved"),
                msg_type);
            msg_type = tvb_get_ntohs(tvb,offset);
            offset = offset + 2;
            proto_tree_add_item(sm_tree, hf_sm_channel, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset + 2;
            proto_tree_add_item(sm_tree, hf_sm_bearer, tvb, offset, 2, ENC_BIG_ENDIAN);
            offset = offset +2;
            proto_tree_add_item(sm_tree, hf_sm_len, tvb, offset, 2, ENC_BIG_ENDIAN);
            length = tvb_get_ntohs(tvb,offset);
            offset = offset +2;
            proto_item_set_len(ti, 16);

            if (length > 0) {
                next_tvb = tvb_new_subset_length(tvb, offset, length);

                switch (msg_type) {
                case PDU_MTP3_TO_SLT:
                case PDU_MTP3_FROM_SLT:
                    call_dissector(mtp3_handle, next_tvb, pinfo, tree);
                    break;
                case PDU_CONNECT_REQUEST:
                case PDU_CONNECT_CONFIRM:
                    proto_tree_add_item(sm_tree, hf_sm_alignment_type, tvb, offset, 4, ENC_BIG_ENDIAN);
                    break;
                case PDU_DISCONNECT_CONFIRM:
                case PDU_DISCONNECT_INDICATION:
                    proto_tree_add_item(sm_tree, hf_sm_backhaul_reason_code, tvb, offset, 4, ENC_BIG_ENDIAN);
                    break;
                case PDU_RETRIEVAL_REQUEST:
                case PDU_RETRIEVAL_CONFIRM:
                    proto_tree_add_item(sm_tree, hf_sm_retrieval_type, tvb, offset, 4, ENC_BIG_ENDIAN);
                    if (msg_type == PDU_RETRIEVAL_CONFIRM && tvb_get_ntohl(tvb,offset) == 0x01) {
                        offset += 4;
                        proto_tree_add_item(sm_tree, hf_sm_bsn_num, tvb, offset, 4, ENC_BIG_ENDIAN);
                    }
                    break;
                case PDU_LSC_REQUEST:
                case PDU_LSC_CONFIRM:
                    proto_tree_add_item(sm_tree, hf_sm_lsc_state_type, tvb, offset, 4, ENC_BIG_ENDIAN);
                    break;
                case PDU_LSC_INDICATION:
                    proto_tree_add_item(sm_tree, hf_sm_backhaul_event_code, tvb, offset, 4, ENC_BIG_ENDIAN);
                    bh_event_code = tvb_get_ntohl(tvb,offset);
                    if (bh_event_code == 0x02 || bh_event_code == 0x04) {
                        offset += 4;
                        proto_tree_add_item(sm_tree, hf_sm_linkdown_cause_code, tvb, offset, 4, ENC_BIG_ENDIAN);
                    } else if (bh_event_code == 0x06) {
                        offset += 4;
                        proto_tree_add_item(sm_tree, hf_sm_backhaul_cause_code, tvb, offset, 4, ENC_BIG_ENDIAN);
                    }
                    break;
                case PDU_STAT_REQUEST:
                    proto_tree_add_item(sm_tree, hf_sm_stat_request_type, tvb, offset, 4, ENC_BIG_ENDIAN);
                    break;
                default:
                    call_data_dissector(next_tvb, pinfo, tree);
                }
            }
        }
    }

    return tvb_captured_length(tvb);
}

void
proto_register_sm(void)
{
    static hf_register_info hf[] = {
        { &hf_sm_sm_msg_type,
            { "SM Message Type",           "sm.sm_msg_type",
            FT_UINT32, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_protocol,
            { "Protocol Type",           "sm.protocol",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_msg_id,
            { "Message ID",           "sm.msgid",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_msg_type,
            { "Message Type",           "sm.msg_type",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_channel,
            { "Channel ID",           "sm.channel",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_bearer,
            { "Bearer ID",           "sm.bearer",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_len,
            { "Length",           "sm.len",
            FT_UINT16, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_ip_addr,
            { "IPv4 address","sm.ip_addr",
            FT_IPv4,BASE_NONE,  NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_sm_context,
            { "Context","sm.context",
            FT_UINT32, BASE_DEC, NULL, 0x0,
            "Context(guesswork!)", HFILL }
        },
        { &hf_sm_eisup_msg_id,
            { "Message id","sm.eisup_message_id",
            FT_UINT8, BASE_DEC, NULL, 0x0,
            "Message id(guesswork!)", HFILL }
        },
        { &hf_sm_tag,
            { "Tag","sm.tag",
            FT_UINT16, BASE_DEC, NULL, 0x0,
            "Tag(guesswork!)", HFILL }
        },
        { &hf_sm_alignment_type,
          { "Alignment type","sm.connect_type",
            FT_UINT32, BASE_HEX, VALS(sm_alignment_type), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_backhaul_reason_code,
          { "Backhaul reason code","sm.backhaul_reason",
            FT_UINT32, BASE_HEX, VALS(sm_backhaul_reason_code), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_backhaul_event_code,
          { "Backhaul event code","sm.backhaul_event",
            FT_UINT32, BASE_HEX, VALS(sm_backhaul_event_code), 0x0,
                        NULL, HFILL }
        },
        { &hf_sm_backhaul_cause_code,
          { "Backhaul cause code","sm.backhaul_cause",
            FT_UINT32, BASE_HEX, VALS(sm_backhaul_cause_code), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_linkdown_cause_code,
          { "Link down cause","sm.linkdown_reason",
            FT_UINT32, BASE_HEX, VALS(sm_linkdown_cause_code), 0x0,
            NULL, HFILL }
        },

        { &hf_sm_retrieval_type,
          { "Retrieval type","sm.retrieval_type",
            FT_UINT32, BASE_HEX, VALS(sm_retrieval_type), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_lsc_state_type,
          { "LSC Request type","sm.lsc_state_type",
            FT_UINT32, BASE_HEX, VALS(sm_lsc_state_type), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_stat_request_type,
          { "Statistic request type","sm.stat_request_type",
            FT_UINT32, BASE_HEX, VALS(sm_stat_request_type), 0x0,
            NULL, HFILL }
        },
        { &hf_sm_bsn_num,
          { "BSN","sm.bsn_num",
            FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },

    };

/* Setup protocol subtree array */
    static int *ett[] = {
        &ett_sm,
    };

/* Register the protocol name and description */
    proto_sm = proto_register_protocol("Cisco Session Management",
        "SM", "sm");

    register_dissector("sm", dissect_sm, proto_sm);

/* Required function calls to register the header fields and subtrees used */
    proto_register_field_array(proto_sm, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_sm(void)
{
    sdp_handle  = find_dissector_add_dependency("sdp", proto_sm);
    mtp3_handle = find_dissector_add_dependency("mtp3", proto_sm);
    q931_handle = find_dissector_add_dependency("q931", proto_sm);
}

/*
 * 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:
 */