/* packet-wtp.c

 *

 * Routines to dissect WTP component of WAP traffic.

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * WAP dissector based on original work by Ben Fowler

 * Updated by Neil Hunter <neil.hunter@energis-squared.com>

 * WTLS support by Alexandre P. Ferreira (Splice IP)

 *

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

 */

#include "config.h"

#define WS_LOG_DOMAIN "packet-wtp"

#include <wireshark.h>

#include <epan/packet.h>

#include <epan/reassemble.h>

#include <epan/tfs.h>

#include <wsutil/array.h>

#include "packet-wap.h"

#include "packet-wtp.h"

#include "packet-wsp.h"

void proto_register_wtp(void);

void proto_reg_handoff_wtp(void);

static const true_false_string continue_truth = {

    "TPI Present" ,

    "No TPI"

};

static const true_false_string RID_truth = {

    "Re-Transmission",

    "First transmission"

};

static const true_false_string TIDNew_truth = {

    "TID is new" ,

    "TID is valid"

};

static const true_false_string tid_response_truth = {

    "Response" ,

    "Original"

};

static const true_false_string UP_truth = {

    "User Acknowledgement required" ,

    "User Acknowledgement optional"

};

static const value_string vals_wtp_pdu_type[] = {

    { 0, "Not Allowed" },

    { 1, "Invoke" },

    { 2, "Result" },

    { 3, "Ack" },

    { 4, "Abort" },

    { 5, "Segmented Invoke" },

    { 6, "Segmented Result" },

    { 7, "Negative Ack" },

    { 0, NULL }

};

static const value_string vals_transaction_trailer[] = {

    { 0, "Not last packet" },

    { 1, "Last packet of message" },

    { 2, "Last packet of group" },

    { 3, "Re-assembly not supported" },

    { 0, NULL }

};

static const value_string vals_version[] = {

    { 0, "Current" },

    { 1, "Undefined" },

    { 2, "Undefined" },

    { 3, "Undefined" },

    { 0, NULL }

};

static const value_string vals_abort_type[] = {

    { 0, "Provider" },

    { 1, "User (WSP)" },

    { 0, NULL }

};

static const value_string vals_abort_reason_provider[] = {

    { 0x00, "Unknown" },

    { 0x01, "Protocol Error" },

    { 0x02, "Invalid TID" },

    { 0x03, "Not Implemented Class 2" },

    { 0x04, "Not Implemented SAR" },

    { 0x05, "Not Implemented User Acknowledgement" },

    { 0x06, "WTP Version Zero" },

    { 0x07, "Capacity Temporarily Exceeded" },

    { 0x08, "No Response" },

    { 0x09, "Message Too Large" },

    { 0x00, NULL }

};

static const value_string vals_transaction_classes[] = {

    { 0x00, "Unreliable Invoke without Result" },

    { 0x01, "Reliable Invoke without Result" },

    { 0x02, "Reliable Invoke with Reliable Result" },

    { 0x00, NULL }

};

static const value_string vals_tpi_type[] = {

    { 0x00, "Error" },

    { 0x01, "Info" },

    { 0x02, "Option" },

    { 0x03, "Packet sequence number" },

    { 0x04, "SDU boundary" },

    { 0x05, "Frame boundary" },

    { 0x00, NULL }

};

static const value_string vals_tpi_opt[] = {

    { 0x01, "Maximum receive unit" },

    { 0x02, "Total message size" },

    { 0x03, "Delay transmission timer" },

    { 0x04, "Maximum group" },

    { 0x05, "Current TID" },

    { 0x06, "No cached TID" },

    { 0x00, NULL }

};

/* File scoped variables for the protocol and registered fields */

static int proto_wtp;

/* These fields used by fixed part of header */

static int hf_wtp_header_sub_pdu_size;

static int hf_wtp_header_flag_continue;

static int hf_wtp_header_pdu_type;

static int hf_wtp_header_flag_Trailer;

static int hf_wtp_header_flag_RID;

static int hf_wtp_header_flag_TID;

static int hf_wtp_header_flag_TID_response;

/* These fields used by Invoke packets */

static int hf_wtp_header_Inv_version;

static int hf_wtp_header_Inv_flag_TIDNew;

static int hf_wtp_header_Inv_flag_UP;

static int hf_wtp_header_Inv_Reserved;

static int hf_wtp_header_Inv_TransactionClass;

/* static int hf_wtp_header_variable_part; */

/* static int hf_wtp_data; */

static int hf_wtp_tpi_type;

static int hf_wtp_tpi_psn;

static int hf_wtp_tpi_opt;

static int hf_wtp_tpi_optval;

static int hf_wtp_tpi_info;

static int hf_wtp_header_Ack_flag_TVETOK;

static int hf_wtp_header_Abort_type;

static int hf_wtp_header_Abort_reason_provider;

static int hf_wtp_header_Abort_reason_user;

static int hf_wtp_header_sequence_number;

static int hf_wtp_header_missing_packets;

static int hf_wtp_payload;

/* These fields used when reassembling WTP fragments */

static int hf_wtp_fragments;

static int hf_wtp_fragment;

static int hf_wtp_fragment_overlap;

static int hf_wtp_fragment_overlap_conflict;

static int hf_wtp_fragment_multiple_tails;

static int hf_wtp_fragment_too_long_fragment;

static int hf_wtp_fragment_error;

static int hf_wtp_fragment_count;

static int hf_wtp_reassembled_in;

static int hf_wtp_reassembled_length;

/* Initialize the subtree pointers */

static int ett_wtp;

static int ett_wtp_sub_pdu_tree;

static int ett_header;

static int ett_tpilist;

static int ett_wsp_fragments;

static int ett_wtp_fragment;

static const fragment_items wtp_frag_items = {

    &ett_wtp_fragment,

    &ett_wsp_fragments,

    &hf_wtp_fragments,

    &hf_wtp_fragment,

    &hf_wtp_fragment_overlap,

    &hf_wtp_fragment_overlap_conflict,

    &hf_wtp_fragment_multiple_tails,

    &hf_wtp_fragment_too_long_fragment,

    &hf_wtp_fragment_error,

    &hf_wtp_fragment_count,

    &hf_wtp_reassembled_in,

    &hf_wtp_reassembled_length,

    /* Reassembled data field */

    NULL,

    "fragments"

};

/* Handle for WSP dissector */

static dissector_handle_t wsp_handle;

static dissector_handle_t wtp_fromudp_handle;

/*

 * reassembly of WSP

 */

static reassembly_table wtp_reassembly_table;

/*

 * Extract some bitfields

 */

#define pdu_type(octet)             (((octet) >> 3) & 0x0F) /* Note pdu type must not be 0x00 */

#define transaction_class(octet)    ((octet) & 0x03)    /* ......XX */

#define transmission_trailer(octet) (((octet) >> 1) & 0x01)    /* ......X. */

static char retransmission_indicator(unsigned char octet)

{

    switch (pdu_type(octet)) {

        case INVOKE:

        case RESULT:

        case ACK:

        case SEGMENTED_INVOKE:

        case SEGMENTED_RESULT:

        case NEGATIVE_ACK:

            return octet & 0x01;    /* .......X */

        default:

            return 0;

    }

}

/*

 * dissect a TPI

 */

static void

wtp_handle_tpi(proto_tree *tree, tvbuff_t *tvb)

{

    int            offset = 0;

    unsigned char  tByte;

    unsigned char  tType;

    unsigned char  tLen;

    proto_tree    *subTree = NULL;

    proto_item    *pi;

    tByte = tvb_get_uint8(tvb, offset++);

    tType = (tByte & 0x78) >> 3;

    if (tByte & 0x04)                /* Long TPI    */

        tLen = tvb_get_uint8(tvb, offset++);

    else

        tLen = tByte & 0x03;

    pi = proto_tree_add_uint(tree, hf_wtp_tpi_type,

            tvb, 0, tvb_captured_length(tvb), tType);

    subTree = proto_item_add_subtree(pi, ett_tpilist);

    switch (tType) {

        case 0x00:            /* Error*/

            /* \todo    */

            break;

        case 0x01:            /* Info    */

            /* Beware, untested case here    */

            proto_tree_add_item(subTree, hf_wtp_tpi_info,

                    tvb, offset, tLen, ENC_NA);

            break;

        case 0x02:            /* Option    */

            proto_tree_add_item(subTree, hf_wtp_tpi_opt,

                    tvb, offset++, 1, ENC_LITTLE_ENDIAN);

            proto_tree_add_item(subTree, hf_wtp_tpi_optval,

                    tvb, offset, tLen - 1, ENC_NA);

            break;

        case 0x03:            /* PSN    */

            proto_tree_add_item(subTree, hf_wtp_tpi_psn,

                    tvb, offset, 1, ENC_LITTLE_ENDIAN);

            break;

        case 0x04:            /* SDU boundary    */

            /* \todo    */

            break;

        case 0x05:            /* Frame boundary    */

            /* \todo    */

            break;

        default:

            break;

    }

}

/* Code to actually dissect the packets */

static void

// NOLINTNEXTLINE(misc-no-recursion)

dissect_wtp_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)

{

    wmem_strbuf_t *szInfo;

    int            offCur        = 0;   /* current offset from start of WTP data */

    unsigned char  b0;

    /* continuation flag */

    unsigned char  fCon;            /* Continue flag    */

    unsigned char  fRID;            /* Re-transmission indicator*/

    unsigned char  fTTR = '\0';        /* Transmission trailer    */

    unsigned       cbHeader       = 0;    /* Fixed header length    */

    unsigned       vHeader       = 0;    /* Variable header length*/

    int            abortType      = 0;

    /* Set up structures we'll need to add the protocol subtree and manage it */

    proto_item    *ti = NULL;

    proto_tree    *wtp_tree = NULL;

    char           pdut;

    char           clsTransaction = 3;

    int            numMissing = 0;        /* Number of missing packets in a negative ack */

    int            i;

    tvbuff_t      *wsp_tvb = NULL;

    uint8_t        psn = 0;        /* Packet sequence number*/

    uint16_t       TID = 0;        /* Transaction-Id    */

    int            dataOffset;

    int            dataLen;

    b0 = tvb_get_uint8 (tvb, offCur + 0);

    /* Discover Concatenated PDUs */

    if (b0 == 0) {

        unsigned c_fieldlen = 0;        /* Length of length-field    */

        unsigned c_pdulen = 0;        /* Length of conc. PDU    */

        if (tree) {

            ti = proto_tree_add_item(tree, proto_wtp,

                    tvb, offCur, 1, ENC_NA);

            wtp_tree = proto_item_add_subtree(ti, ett_wtp_sub_pdu_tree);

            proto_item_append_text(ti, ", PDU concatenation");

        }

        offCur = 1;

        i = 1;

        while (offCur < (int) tvb_reported_length(tvb)) {

            tvbuff_t *wtp_tvb;

            /* The length of an embedded WTP PDU is coded as either:

             *    - a 7-bit value contained in one octet with highest bit == 0.

             *    - a 15-bit value contained in two octets (little endian)

             *      if the 1st octet has its highest bit == 1.

             * This means that this is NOT encoded as an uintvar-integer!!!

             */

            b0 = tvb_get_uint8(tvb, offCur + 0);

            if (b0 & 0x80) {

                c_fieldlen = 2;

                c_pdulen = ((b0 & 0x7f) << 8) | tvb_get_uint8(tvb, offCur + 1);

            } else {

                c_fieldlen = 1;

                c_pdulen = b0;

            }

            if (tree) {

                proto_tree_add_uint(wtp_tree, hf_wtp_header_sub_pdu_size,

                        tvb, offCur, c_fieldlen, c_pdulen);

            }

            if (i > 1) {

                col_append_str(pinfo->cinfo, COL_INFO, ", ");

            }

            /* Skip the length field for the WTP sub-tvb */

            wtp_tvb = tvb_new_subset_length(tvb, offCur + c_fieldlen, c_pdulen);

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

            dissect_wtp_common(wtp_tvb, pinfo, wtp_tree);

            offCur += c_fieldlen + c_pdulen;

            i++;

        }

        if (tree) {

            proto_item_append_text(ti, ", PDU count: %u", i);

        }

        return;

    }

    /* No concatenation */

    fCon = b0 & 0x80;

    fRID = retransmission_indicator(b0);

    pdut = pdu_type(b0);

    ws_debug("WTP packet %u: tree = %p, pdu = %s (%u) length: %u\n",

            pinfo->num, tree,

            val_to_str(pinfo->pool,pdut, vals_wtp_pdu_type, "Unknown PDU type 0x%x"),

            pdut, tvb_captured_length(tvb));

    szInfo = wmem_strbuf_new(pinfo->pool, "");

    /* Develop the string to put in the Info column */

    wmem_strbuf_append_printf(szInfo, "WTP %s",

            val_to_str(pinfo->pool,pdut, vals_wtp_pdu_type, "Unknown PDU type 0x%x"));

    switch (pdut) {

        case INVOKE:

            fTTR = transmission_trailer(b0);

            TID = tvb_get_ntohs(tvb, offCur + 1);

            psn = 0;

            clsTransaction = transaction_class(tvb_get_uint8(tvb, offCur + 3));

            wmem_strbuf_append_printf(szInfo, " Class %d", clsTransaction);

            cbHeader = 4;

            break;

        case SEGMENTED_INVOKE:

        case SEGMENTED_RESULT:

            fTTR = transmission_trailer(b0);

            TID = tvb_get_ntohs(tvb, offCur + 1);

            psn = tvb_get_uint8(tvb, offCur + 3);

            if (psn != 0) {

                wmem_strbuf_append_printf(szInfo, " (%u)", psn);

            }

            cbHeader = 4;

            break;

        case ABORT:

            cbHeader = 4;

            break;

        case RESULT:

            fTTR = transmission_trailer(b0);

            TID = tvb_get_ntohs(tvb, offCur + 1);

            psn = 0;

            cbHeader = 3;

            break;

        case ACK:

            cbHeader = 3;

            break;

        case NEGATIVE_ACK:

            /* Variable number of missing packets */

            numMissing = tvb_get_uint8(tvb, offCur + 3);

            cbHeader = numMissing + 4;

            break;

        default:

            break;

    };

    if (fRID) {

        wmem_strbuf_append(szInfo, " R" );

        /*str_index += MIN(returned_length, SZINFO_SIZE-str_index);*/

    };

    /* In the interest of speed, if "tree" is NULL, don't do any work not

       necessary to generate protocol tree items. */

    if (tree) {

        ws_debug("cbHeader = %d", cbHeader);

        /* NOTE - Length will be set when we process the TPI */

        ti = proto_tree_add_item(tree, proto_wtp, tvb, offCur, -1, ENC_NA);

        ws_debug("(7) Returned from proto_tree_add_item");

        wtp_tree = proto_item_add_subtree(ti, ett_wtp);

        /* Code to process the packet goes here */

        ws_debug("cbHeader=%d offCur=%d", cbHeader, offCur);

        /* Add common items: only CON and PDU Type */

        proto_tree_add_item(

                wtp_tree,             /* tree */

                hf_wtp_header_flag_continue,     /* id */

                tvb,

                offCur,             /* start of highlight */

                1,                /* length of highlight*/

                b0                /* value */

                );

        proto_tree_add_item(wtp_tree, hf_wtp_header_pdu_type, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

        switch(pdut) {

            case INVOKE:

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_version , tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_flag_TIDNew, tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_flag_UP, tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_Reserved, tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_Inv_TransactionClass, tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_item_append_text(ti,

                        ", PDU: Invoke (%u)"

                        ", Transaction Class: %s (%u)",

                        INVOKE,

                        val_to_str_const(clsTransaction, vals_transaction_classes, "Undefined"),

                        clsTransaction);

                break;

            case RESULT:

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_item_append_text(ti, ", PDU: Result (%u)", RESULT);

                break;

            case ACK:

                proto_tree_add_item(wtp_tree, hf_wtp_header_Ack_flag_TVETOK, tvb, offCur, 1, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_item_append_text(ti, ", PDU: ACK (%u)", ACK);

                break;

            case ABORT:

                abortType = tvb_get_uint8 (tvb, offCur) & 0x07;

                proto_tree_add_item(wtp_tree, hf_wtp_header_Abort_type , tvb, offCur , 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                if (abortType == PROVIDER) {

                    uint8_t reason = tvb_get_uint8(tvb, offCur + 3);

                    proto_tree_add_item( wtp_tree, hf_wtp_header_Abort_reason_provider , tvb, offCur + 3 , 1, ENC_LITTLE_ENDIAN);

                    proto_item_append_text(ti,

                            ", PDU: Abort (%u)"

                            ", Type: Provider (%u)"

                            ", Reason: %s (%u)",

                            ABORT,

                            PROVIDER,

                            val_to_str_const(reason, vals_abort_reason_provider, "Undefined"),

                            reason);

                }

                else if (abortType == USER) {

                    uint8_t reason = tvb_get_uint8(tvb, offCur + 3);

                    proto_tree_add_item(wtp_tree, hf_wtp_header_Abort_reason_user , tvb, offCur + 3 , 1, ENC_LITTLE_ENDIAN);

                    proto_item_append_text(ti,

                            ", PDU: Abort (%u)"

                            ", Type: User (%u)"

                            ", Reason: %s (%u)",

                            ABORT,

                            PROVIDER,

                            val_to_str_ext_const(reason, &vals_wsp_reason_codes_ext, "Undefined"),

                            reason);

                }

                break;

            case SEGMENTED_INVOKE:

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number , tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_item_append_text(ti,

                        ", PDU: Segmented Invoke (%u)"

                        ", Packet Sequence Number: %u",

                        SEGMENTED_INVOKE, psn);

                break;

            case SEGMENTED_RESULT:

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_Trailer, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number , tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                proto_item_append_text(ti,

                        ", PDU: Segmented Result (%u)"

                        ", Packet Sequence Number: %u",

                        SEGMENTED_RESULT, psn);

                break;

            case NEGATIVE_ACK:

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_RID, tvb, offCur, 1, ENC_LITTLE_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID_response, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_flag_TID, tvb, offCur + 1, 2, ENC_BIG_ENDIAN);

                proto_tree_add_item(wtp_tree, hf_wtp_header_missing_packets , tvb, offCur + 3, 1, ENC_LITTLE_ENDIAN);

                /* Iterate through missing packets */

                for (i = 0; i < numMissing; i++)

                {

                    proto_tree_add_item(wtp_tree, hf_wtp_header_sequence_number, tvb, offCur + 4 + i, 1, ENC_LITTLE_ENDIAN);

                }

                proto_item_append_text(ti,

                        ", PDU: Negative Ack (%u)"

                        ", Missing Packets: %u",

                        NEGATIVE_ACK, numMissing);

                break;

            default:

                break;

        };

        if (fRID) {

            proto_item_append_text(ti, ", Retransmission");

        }

    } else { /* tree is NULL */

        ws_debug("(4) tree was %p", tree);

    }

    /* Process the variable part */

    if (fCon) {            /* Now, analyze variable part    */

        uint8_t   tCon;

        uint8_t   tByte;

        unsigned  tpiLen;

        tvbuff_t *tmp_tvb;

        vHeader = 0;        /* Start scan all over    */

        do {

            tByte = tvb_get_uint8(tvb, offCur + cbHeader + vHeader);

            tCon = tByte & 0x80;

            if (tByte & 0x04)    /* Long TPI    */

                tpiLen = 2 + tvb_get_uint8(tvb, offCur + cbHeader + vHeader + 1);

            else

                tpiLen = 1 + (tByte & 0x03);

            if (tree)

            {

                tmp_tvb = tvb_new_subset_length(tvb, offCur + cbHeader + vHeader, tpiLen);

                wtp_handle_tpi(wtp_tree, tmp_tvb);

            }

            vHeader += tpiLen;

        } while (tCon);

    } else {

        /* There is no variable part */

    }    /* End of variable part of header */

    /* Set the length of the WTP protocol part now we know the length of the

     * fixed and variable WTP headers */

    if (tree)

        proto_item_set_len(ti, cbHeader + vHeader);

    ws_debug("cbHeader = %d", cbHeader);

    /*

     * Any remaining data ought to be WSP data (if not WTP ACK, NACK

     * or ABORT pdu), so, if we have any remaining data, and it's

     * not an ACK, NACK, or ABORT PDU, hand it off (defragmented) to the

     * WSP dissector.

     * Note that the last packet of a fragmented WTP message needn't

     * contain any data, so we allow payloadless packets to be

     * reassembled.  (XXX - does the reassembly code handle this

     * for packets other than the last packet?)

     *

     * Try calling a subdissector only if:

     *    - The WTP payload is resembled in this very packet,

     *    - The WTP payload is not fragmented across packets.

     */

    dataOffset = offCur + cbHeader + vHeader;

    dataLen = tvb_reported_length_remaining(tvb, dataOffset);

    if ((dataLen >= 0) &&

            ! ((pdut==ACK) || (pdut==NEGATIVE_ACK) || (pdut==ABORT)))

    {

        /* Try to reassemble if needed, and hand over to WSP

         * A fragmented WTP packet is either:

         *    - An INVOKE with fTTR (transmission trailer) not set,

         *    - a SEGMENTED_INVOKE,

         *    - A RESULT with fTTR (transmission trailer) not set,

         *    - a SEGMENTED_RESULT.

         */

        if ( ( (pdut == SEGMENTED_INVOKE) || (pdut == SEGMENTED_RESULT)

                    || ( ((pdut == INVOKE) || (pdut == RESULT)) && (!fTTR) )

             ) && tvb_bytes_exist(tvb, dataOffset, dataLen) )

        {

            /* Try reassembling fragments */

            fragment_head *fd_wtp = NULL;

            uint32_t reassembled_in = 0;

            bool save_fragmented = pinfo->fragmented;

            pinfo->fragmented = true;

            fd_wtp = fragment_add_seq(&wtp_reassembly_table, tvb, dataOffset,

                    pinfo, TID, NULL, psn, dataLen, !fTTR, 0);

            /* XXX - fragment_add_seq() yields NULL unless Wireshark knows

             * that the packet is part of a reassembled whole. This means

             * that fd_wtp will be NULL as long as Wireshark did not encounter

             * (and process) the packet containing the last fragment.

             * This implies that Wireshark needs two passes over the data for

             * correct reassembly. At the first pass, a capture containing

             * three fragments plus a retransmission of the last fragment

             * will progressively show:

             *

             *        Packet 1: (Unreassembled fragment 1)

             *        Packet 2: (Unreassembled fragment 2)

             *        Packet 3: (Reassembled WTP)

             *        Packet 4: (WTP payload reassembled in packet 3)

             *

             * However at subsequent evaluation (e.g., by applying a display

             * filter) the packet summary will show:

             *

             *        Packet 1: (WTP payload reassembled in packet 3)

             *        Packet 2: (WTP payload reassembled in packet 3)

             *        Packet 3: (Reassembled WTP)

             *        Packet 4: (WTP payload reassembled in packet 3)

             *

             * This is important to know, and also affects read filters!

             */

            wsp_tvb = process_reassembled_data(tvb, dataOffset, pinfo,

                    "Reassembled WTP", fd_wtp, &wtp_frag_items,

                    NULL, wtp_tree);

            ws_debug("WTP: Packet %u %s -> %d: wsp_tvb = %p, fd_wtp = %p",

                    pinfo->num,

                    fd_wtp ? "Reassembled" : "Not reassembled",

                    fd_wtp ? fd_wtp->reassembled_in : 0,

                    wsp_tvb,

                    fd_wtp

                  );

            if (fd_wtp) {

                /* Reassembled */

                reassembled_in = fd_wtp->reassembled_in;

                if (pinfo->num == reassembled_in) {

                    /* Reassembled in this very packet:

                     * We can safely hand the tvb to the WSP dissector */

                    call_dissector(wsp_handle, wsp_tvb, pinfo, tree);

                } else {

                    /* Not reassembled in this packet */

                    col_append_fstr(pinfo->cinfo, COL_INFO,

                            "%s (WTP payload reassembled in packet %u)",

                            wmem_strbuf_get_str(szInfo), fd_wtp->reassembled_in);

                    proto_tree_add_item(wtp_tree, hf_wtp_payload, tvb, dataOffset, -1, ENC_NA);

                }

            } else {

                /* Not reassembled yet, or not reassembled at all */

                col_append_fstr(pinfo->cinfo, COL_INFO,

                        "%s (Unreassembled fragment %u)",

                        wmem_strbuf_get_str(szInfo), psn);

                proto_tree_add_item(wtp_tree, hf_wtp_payload, tvb, dataOffset, -1, ENC_NA);

            }

            /* Now reset fragmentation information in pinfo */

            pinfo->fragmented = save_fragmented;

        }

        else if ( ((pdut == INVOKE) || (pdut == RESULT)) && (fTTR) )

        {

            /* Non-fragmented payload */

            wsp_tvb = tvb_new_subset_remaining(tvb, dataOffset);

            /* We can safely hand the tvb to the WSP dissector */

            call_dissector(wsp_handle, wsp_tvb, pinfo, tree);

        }

        else

        {

            /* Nothing to hand to subdissector */

            col_append_str(pinfo->cinfo, COL_INFO, wmem_strbuf_get_str(szInfo));

        }

    }

    else

    {

        /* Nothing to hand to subdissector */

        col_append_str(pinfo->cinfo, COL_INFO, wmem_strbuf_get_str(szInfo));

    }

}

/*

 * Called directly from UDP.

 * Put "WTP+WSP" into the "Protocol" column.

 */

static int

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

{

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "WTP+WSP");

    col_clear(pinfo->cinfo, COL_INFO);

    dissect_wtp_common(tvb, pinfo, tree);

    return tvb_captured_length(tvb);

}

/*

 * Called from a higher-level WAP dissector, presumably WTLS.

 * Put "WTLS+WSP+WTP" to the "Protocol" column.

 *

 * XXX - is this supposed to be called from WTLS?  If so, we're not

 * calling it....

 *

 * XXX - can this be called from any other dissector?

 */

static int

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

{

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "WTLS+WTP+WSP");

    col_clear(pinfo->cinfo, COL_INFO);

    dissect_wtp_common(tvb, pinfo, tree);

    return tvb_captured_length(tvb);

}

/* Register the protocol with Wireshark */

void

proto_register_wtp(void)

{

    /* Setup list of header fields */

    static hf_register_info hf[] = {

        { &hf_wtp_header_sub_pdu_size,

            { "Sub PDU size", "wtp.sub_pdu_size",

                FT_UINT16, BASE_DEC, NULL, 0x0,

                "Size of Sub-PDU (bytes)", HFILL

            }

        },

        { &hf_wtp_header_flag_continue,

            { "Continue Flag", "wtp.continue_flag",

                FT_BOOLEAN, 8, TFS( &continue_truth ), 0x80,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_pdu_type,

            { "PDU Type", "wtp.pdu_type",

                FT_UINT8, BASE_HEX, VALS( vals_wtp_pdu_type ), 0x78,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_flag_Trailer,

            { "Trailer Flags", "wtp.trailer_flags",

                FT_UINT8, BASE_HEX, VALS( vals_transaction_trailer ), 0x06,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_flag_RID,

            { "Re-transmission Indicator", "wtp.RID",

                FT_BOOLEAN, 8, TFS( &RID_truth ), 0x01,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_flag_TID_response,

            { "TID Response", "wtp.TID.response",

                FT_BOOLEAN, 16, TFS( &tid_response_truth ), 0x8000,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_flag_TID,

            { "Transaction ID", "wtp.TID",

                FT_UINT16, BASE_HEX, NULL, 0x7FFF,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Inv_version,

            { "Version", "wtp.header.version",

                FT_UINT8, BASE_HEX, VALS( vals_version ), 0xC0,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Inv_flag_TIDNew,

            { "TIDNew", "wtp.header.TIDNew",

                FT_BOOLEAN, 8, TFS( &TIDNew_truth ), 0x20,

                NULL, HFILL

        }

        },

        { &hf_wtp_header_Inv_flag_UP,

            { "U/P flag", "wtp.header.UP",

                FT_BOOLEAN, 8, TFS( &UP_truth ), 0x10,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Inv_Reserved,

            { "Reserved", "wtp.inv.reserved",

                FT_UINT8, BASE_HEX, NULL, 0x0C,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Inv_TransactionClass,

            { "Transaction Class", "wtp.inv.transaction_class",

                FT_UINT8, BASE_HEX, VALS( vals_transaction_classes ), 0x03,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Ack_flag_TVETOK,

            { "Tve/Tok flag", "wtp.ack.tvetok",

                FT_BOOLEAN, 8, NULL, 0x04,

                NULL, HFILL

            }

    },

        { &hf_wtp_header_Abort_type,

            { "Abort Type", "wtp.abort.type",

                FT_UINT8, BASE_HEX, VALS ( vals_abort_type ), 0x07,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_Abort_reason_provider,

            { "Abort Reason", "wtp.abort.reason.provider",

                FT_UINT8, BASE_HEX, VALS ( vals_abort_reason_provider ), 0x00,

                NULL, HFILL

            }

        },

        /* Assume WSP is the user and use its reason codes */

        { &hf_wtp_header_Abort_reason_user,

            { "Abort Reason", "wtp.abort.reason.user",

                FT_UINT8, BASE_HEX|BASE_EXT_STRING, &vals_wsp_reason_codes_ext, 0x00,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_sequence_number,

            { "Packet Sequence Number", "wtp.header.sequence",

                FT_UINT8, BASE_DEC, NULL, 0x00,

                NULL, HFILL

            }

        },

        { &hf_wtp_header_missing_packets,

            { "Missing Packets", "wtp.header.missing_packets",

                FT_UINT8, BASE_DEC, NULL, 0x00,

                NULL, HFILL

            }

        },

        { &hf_wtp_payload,

            { "Payload", "wtp.payload",

                FT_BYTES, BASE_NONE, NULL, 0x00,

                NULL, HFILL

            }

        },

#if 0

        { &hf_wtp_header_variable_part,

            { "Header: Variable part", "wtp.header_variable_part",

                FT_BYTES, BASE_NONE, NULL, 0x0,

                "Variable part of the header", HFILL

            }

        },

        { &hf_wtp_data,

            { "Data", "wtp.header_data",

                FT_BYTES, BASE_NONE, NULL, 0x0,

                NULL, HFILL

            }

        },

#endif

        { &hf_wtp_tpi_type,

            { "TPI", "wtp.tpi",

                FT_UINT8, BASE_HEX, VALS(vals_tpi_type), 0x00,

                "Identification of the Transport Information Item", HFILL

            }

        },

        { &hf_wtp_tpi_psn,

            { "Packet sequence number", "wtp.tpi.psn",

                FT_UINT8, BASE_DEC, NULL, 0x00,

                "Sequence number of this packet", HFILL

        }

        },

        { &hf_wtp_tpi_opt,

            { "Option", "wtp.tpi.opt",

                FT_UINT8, BASE_HEX, VALS(vals_tpi_opt), 0x00,

                "The given option for this TPI", HFILL

            }

        },

        { &hf_wtp_tpi_optval,

            { "Option Value", "wtp.tpi.opt.val",

                FT_NONE, BASE_NONE, NULL, 0x00,

                "The value that is supplied with this option", HFILL

            }

        },

        { &hf_wtp_tpi_info,

            { "Information", "wtp.tpi.info",

                FT_NONE, BASE_NONE, NULL, 0x00,

                "The information being send by this TPI", HFILL

            }

        },

        /* Fragment fields */

        { &hf_wtp_fragment_overlap,

            { "Fragment overlap", "wtp.fragment.overlap",

                FT_BOOLEAN, BASE_NONE, NULL, 0x0,

                "Fragment overlaps with other fragments", HFILL

            }

        },

        { &hf_wtp_fragment_overlap_conflict,

            { "Conflicting data in fragment overlap", "wtp.fragment.overlap.conflict",

                FT_BOOLEAN, BASE_NONE, NULL, 0x0,

                "Overlapping fragments contained conflicting data", HFILL

            }

        },

        { &hf_wtp_fragment_multiple_tails,

            { "Multiple tail fragments found", "wtp.fragment.multipletails",

                FT_BOOLEAN, BASE_NONE, NULL, 0x0,

                "Several tails were found when defragmenting the packet", HFILL

            }

        },

        { &hf_wtp_fragment_too_long_fragment,

            { "Fragment too long", "wtp.fragment.toolongfragment",

                FT_BOOLEAN, BASE_NONE, NULL, 0x0,

                "Fragment contained data past end of packet", HFILL

            }

        },

        { &hf_wtp_fragment_error,

            { "Defragmentation error", "wtp.fragment.error",

                FT_FRAMENUM, BASE_NONE, NULL, 0x0,

                "Defragmentation error due to illegal fragments", HFILL

            }

        },

        { &hf_wtp_fragment_count,

            { "Fragment count", "wtp.fragment.count",

                FT_UINT32, BASE_DEC, NULL, 0x0,

                NULL, HFILL

            }

        },

        { &hf_wtp_reassembled_in,

            { "Reassembled in", "wtp.reassembled.in",

                FT_FRAMENUM, BASE_NONE, NULL, 0x0,

                "WTP fragments are reassembled in the given packet", HFILL

            }

        },

        { &hf_wtp_reassembled_length,

            { "Reassembled WTP length", "wtp.reassembled.length",

                FT_UINT32, BASE_DEC, NULL, 0x0,

                "The total length of the reassembled payload", HFILL

            }

        },

        { &hf_wtp_fragment,

            { "WTP Fragment", "wtp.fragment",

                FT_FRAMENUM, BASE_NONE, NULL, 0x0,

                NULL, HFILL

            }

        },

        { &hf_wtp_fragments,

            { "WTP Fragments", "wtp.fragments",

                FT_NONE, BASE_NONE, NULL, 0x0,

                NULL, HFILL

            }

        },

    };

    /* Setup protocol subtree array */

    static int *ett[] = {

        &ett_wtp,

        &ett_wtp_sub_pdu_tree,

        &ett_header,

        &ett_tpilist,

        &ett_wsp_fragments,

        &ett_wtp_fragment,

    };

    /* Register the protocol name and description */

    /* Abbreviated protocol name should Match IANA: https://www.iana.org/assignments/port-numbers/ */

    proto_wtp = proto_register_protocol("Wireless Transaction Protocol", "WTP", "wtp");

    /* Required calls to register the header fields and subtrees used */

    proto_register_field_array(proto_wtp, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

    register_dissector("wtp-wtls", dissect_wtp_fromwtls, proto_wtp);

    wtp_fromudp_handle = register_dissector("wtp-udp", dissect_wtp_fromudp, proto_wtp);

    reassembly_table_register(&wtp_reassembly_table,

                          &addresses_reassembly_table_functions);

}

void

proto_reg_handoff_wtp(void)

{

    /*

     * Get a handle for the connection-oriented WSP dissector - if WTP

     * PDUs have data, it is WSP.

     */

    wsp_handle = find_dissector_add_dependency("wsp-co", proto_wtp);

    dissector_add_uint_with_preference("udp.port", UDP_PORT_WTP_WSP, wtp_fromudp_handle);

    dissector_add_uint("gsm_sms_ud.udh.port", UDP_PORT_WTP_WSP, wtp_fromudp_handle);

    dissector_add_uint("gsm_sms.udh.port", UDP_PORT_WTP_WSP, wtp_fromudp_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:

 */