Wireshark-dev: [Wireshark-dev] Plugin crash
From: "Matt Poduska" <[email protected]>
Date: Wed, 18 Jun 2008 10:08:53 -0500
I'm working to build a new protocol dissector as a plugin. My plugin used to load and work properly, but I've recently (within the last few weeks or so) updated to the SVN head and now my plugin crashes Wireshark at startup (while loading plugins). I've been able to trace the crash to a call to proto_register_field_array (line 682 of the attached file). If I remove the line, the dissector loads properly (but won't dissect properly, of course). I don't know why it's now crashing (I haven't changed the dissector), and I haven't found an acceptable way to debug this type of problem. Any suggestions?

Thanks, Matt
/* packet-llrp.c
 * EPCglobal Low-Level Reader Protocol Packet Dissector
 *
 * Copyright 2008, Intermec Technologies Corp. <[email protected]>
 *
 * $Id: $
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <[email protected]>
 * Copyright 1999 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */   

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <time.h>
#include <glib.h>
#include <epan/filesystem.h>
#include <epan/xmlstub.h>
#include <epan/packet.h>
#include <epan/addr_resolv.h>
#include <epan/report_err.h>
#include <epan/prefs.h>
#include <epan/sminmpec.h>
#include <epan/emem.h>
#include <epan/expert.h>

#include <epan/dissectors/packet-tcp.h>

#include "llrpbuffer.h"
#include "llrpparse.h"
#include "llrpmisc.h"
#include "llrpdef.h"

#define LLRP_DEBUG

#define TCP_PORT_EPC_LLRP            5084    /* IANA assigned TCP port number */
#define PROTO_NAME_LLRP              "llrp"  /* must be lowercase */
#define PROTO_SHORT_DESCRIPTION_LLRP "LLRP"
#define PROTO_DESCRIPTION_LLRP       "EPCglobal RFID Low-Level Reader Protocol"
#define LLRP_MAX_PARAMETER_DEPTH     10

typedef struct
{
    proto_tree *tree[LLRP_MAX_PARAMETER_DEPTH];
    tvbuff_t *tvb;
    packet_info *pinfo;
    int quiet_parse;  /* When nonzero, don't display any parse info */
} t_llrp_parse_info;
static t_llrp_parse_info llrp_parse_info;

/* --------------------------------------------------------------------------------------- */
/* LLRP Buffer Handling                                                                    */

static gint llrp_buffer_offset;

unsigned char *llrp_tvb_BufferRead(t_llrp_buffer buffer, unsigned long length,
 unsigned long *consumed)
{
    size_t read_length;
    unsigned char *result;

    read_length= tvb_length_remaining(buffer, llrp_buffer_offset);
    if(read_length> length)
        read_length= length;
    result= (unsigned char *) tvb_get_ptr(buffer, llrp_buffer_offset, read_length);
    llrp_buffer_offset+= read_length;

    if(consumed!= NULL)
        *consumed= (unsigned long) read_length;

    return result;
}
t_llrp_BufferRead llrp_BufferRead= llrp_tvb_BufferRead;

unsigned long llrp_tvb_BufferGetLength(t_llrp_buffer buffer)
{
    return (unsigned short) tvb_length_remaining(buffer, llrp_buffer_offset);
}
t_llrp_BufferGetLength llrp_BufferGetLength= llrp_tvb_BufferGetLength;

unsigned short use_ntohs(unsigned short value)
{
    return pntohs(&value);
}
t_llrp_ntohs llrp_ntohs= (t_llrp_ntohs) use_ntohs;

unsigned long use_ntohl(unsigned long value)
{
    return pntohl(&value);
}
t_llrp_ntohl llrp_ntohl= (t_llrp_ntohl) use_ntohl;

/* --------------------------------------------------------------------------------------- */
/* Dissector Display Tree Information                                                      */

static int proto_epc_llrp = -1;

/* LLRP message/header */
static gint hf_llrp_message_version = -1;
static gint hf_llrp_message_type = -1;
static gint hf_llrp_message_length = -1;
static gint hf_llrp_message_id = -1;
static gint hf_llrp_message_parm = -1;
static gint hf_llrp_message_field = -1;
static hf_register_info hf_llrp_header[] =
{
    { &hf_llrp_message_version, { "Version", PROTO_NAME_LLRP ".version", FT_UINT8,
                                  BASE_DEC, NULL, 0x00, "llrp message protocol version", HFILL }},
    { &hf_llrp_message_type,    { "Message Type", PROTO_NAME_LLRP ".type", FT_UINT16,
                                  BASE_DEC, NULL, 0x00, "llrp message type", HFILL }},
    { &hf_llrp_message_length,  { "Message Length", PROTO_NAME_LLRP ".length", FT_UINT32,
                                  BASE_DEC, NULL, 0x00, "llrp message total length", HFILL }},
    { &hf_llrp_message_id,      { "Message ID", PROTO_NAME_LLRP ".id", FT_UINT32,
                                  BASE_DEC, NULL, 0x00, "llrp message ID", HFILL }},
    { &hf_llrp_message_parm,    { "Parameter", PROTO_NAME_LLRP ".parameter", FT_UINT16, BASE_DEC,
                                  NULL, 0x00, "llrp message parameter", HFILL }},
    { &hf_llrp_message_field,   { "Field", PROTO_NAME_LLRP ".field", FT_UINT16, BASE_DEC,
                                 NULL, 0x00, "llrp message field", HFILL }}
};
/* LLRP Field */
static gint hf_llrp_field_type = -1;
static gint hf_llrp_field_count = -1;
static gint hf_llrp_field_bitlength = -1;
static gint hf_llrp_field_value_u1 = -1;
static gint hf_llrp_field_value_u2 = -1;
static gint hf_llrp_field_value_u8 = -1;
static gint hf_llrp_field_value_s8 = -1;
static gint hf_llrp_field_value_u16 = -1;
static gint hf_llrp_field_value_s16 = -1;
static gint hf_llrp_field_value_u32 = -1;
static gint hf_llrp_field_value_s32 = -1;
static gint hf_llrp_field_value_u64 = -1;
static gint hf_llrp_field_value_s64 = -1;
static gint hf_llrp_field_value_variable = -1;
static gint hf_llrp_field_enumeration = -1;
static hf_register_info hf_llrp_field[] =
{
    { &hf_llrp_field_type, { "Type", PROTO_NAME_LLRP ".field.type", FT_UINT16, BASE_DEC, NULL,
                             0x00, "llrp field type", HFILL }},
    { &hf_llrp_field_count, { "Count (items)", PROTO_NAME_LLRP ".field.count", FT_UINT16,
                                  BASE_DEC, NULL, 0x00, "llrp field count", HFILL }},
    { &hf_llrp_field_bitlength, { "Length (bits)", PROTO_NAME_LLRP ".field.length", FT_UINT16,
                                  BASE_DEC, NULL, 0x00, "llrp field bitlength", HFILL }},
    { &hf_llrp_field_value_u1, { "Value", PROTO_NAME_LLRP ".field.u1value", FT_UINT8,
                                  BASE_DEC, NULL, 0x00, "llrp field u1 value", HFILL }},
    { &hf_llrp_field_value_u2, { "Value", PROTO_NAME_LLRP ".field.u2value", FT_UINT8,
                                  BASE_DEC, NULL, 0x00, "llrp field u2 value", HFILL }},
    { &hf_llrp_field_value_u8, { "Value", PROTO_NAME_LLRP ".field.u8value", FT_UINT8,
                                  BASE_HEX, NULL, 0x00, "llrp field u8 value", HFILL }},
    { &hf_llrp_field_value_s8, { "Value", PROTO_NAME_LLRP ".field.s8value", FT_INT8,
                                  BASE_HEX, NULL, 0x00, "llrp field s8 value", HFILL }},
    { &hf_llrp_field_value_u16, { "Value", PROTO_NAME_LLRP ".field.u16value", FT_UINT16,
                                  BASE_HEX, NULL, 0x00, "llrp field u16 value", HFILL }},
    { &hf_llrp_field_value_s16, { "Value", PROTO_NAME_LLRP ".field.s16value", FT_INT16,
                                  BASE_HEX, NULL, 0x00, "llrp field s16 value", HFILL }},
    { &hf_llrp_field_value_u32, { "Value", PROTO_NAME_LLRP ".field.u32value", FT_UINT32,
                                  BASE_HEX, NULL, 0x00, "llrp field u32 value", HFILL }},
    { &hf_llrp_field_value_s32, { "Value", PROTO_NAME_LLRP ".field.s32value", FT_INT32,
                                  BASE_HEX, NULL, 0x00, "llrp field s32 value", HFILL }},
    { &hf_llrp_field_value_u64, { "Value", PROTO_NAME_LLRP ".field.u64value", FT_UINT64,
                                  BASE_HEX, NULL, 0x00, "llrp field u64 value", HFILL }},
    { &hf_llrp_field_value_s64, { "Value", PROTO_NAME_LLRP ".field.s64value", FT_INT64,
                                  BASE_HEX, NULL, 0x00, "llrp field s64 value", HFILL }},
    { &hf_llrp_field_value_variable, { "Value", PROTO_NAME_LLRP ".field.variable", FT_STRING,
                                  BASE_NONE, NULL, 0x00, "llrp field variable-length value", HFILL }},
    { &hf_llrp_field_enumeration, { "Enumeration", PROTO_NAME_LLRP ".field.enumeration", FT_STRING,
                                  BASE_NONE, NULL, 0x00, "llrp field enumeration", HFILL }}
};
/* LLRP Parameter */
static gint hf_llrp_parameter_type= -1;
static gint hf_llrp_parameter_length= -1;
static hf_register_info hf_llrp_parameter[]=
{
    { &hf_llrp_parameter_type,   { "Type", PROTO_NAME_LLRP ".parameter.type", FT_UINT16, BASE_DEC,
                                   NULL, 0x00, "", HFILL }},
    { &hf_llrp_parameter_length, { "Length (bytes)", PROTO_NAME_LLRP ".parameter.length", FT_UINT16, BASE_DEC,
                                   NULL, 0x00, "", HFILL }}
};

/* All LLRP dissection display subtrees */
static gint ett_llrp_message = -1;
static gint ett_llrp_field = -1;
static gint ett_llrp_parameter = -1;
static gint *ett_llrp[]=
{
    &ett_llrp_message,
    &ett_llrp_field,
    &ett_llrp_parameter
};  

/* --------------------------------------------------------------------------------------- */
/* WireShark-Specific Parse Handlers                                                       */

static void llrp_ws_DescendParseTree(t_llrp_parse_context *context, t_llrp_parse_info *info,
 proto_tree *tree)
{
    if(context->depth>= LLRP_MAX_PARAMETER_DEPTH)
    {
        #ifdef LLRP_DEBUG
        g_warning("Maximum parse depth exceeded (%u)", context->depth);
        #endif /* LLRP_DEBUG */
        info->quiet_parse= 1;
        return;
    }

    info->quiet_parse= 0;
    info->tree[context->depth]= tree;
}

static void llrp_ws_AscendParseTree(t_llrp_parse_context *context, t_llrp_parse_info *info)
{
    if(context->depth< LLRP_MAX_PARAMETER_DEPTH)
        info->quiet_parse= 0;
}

int llrp_ws_HandleMessageStart(void *context, const unsigned char version,
 const unsigned short type, const unsigned long length, const unsigned long id, const char *name)
{
    proto_item *item;
    proto_tree *tree;
    t_llrp_parse_context *ctxt= (t_llrp_parse_context *) context;
    t_llrp_parse_info *info= (t_llrp_parse_info *) ctxt->data;

    #ifdef LLRP_DEBUG
    g_warning("llrp_ws_HandleMessageStart (type %d)", type);
    #endif /* LLRP_DEBUG */

    if(ctxt->depth!= 0)
    {
        #ifdef LLRP_DEBUG
        g_warning("Invalid parse depth (%d)", ctxt->depth);
        #endif /* LLRP_DEBUG */
        return 0; /* abort parsing */
    }

    if(info->tree[0]== NULL)
    {
        #ifdef LLRP_DEBUG
        g_warning("llrp_ws_HandleMessageStart: no display tree!", type);
        #endif /* LLRP_DEBUG */
        tree= NULL;
        info->quiet_parse= 1;
    }
    else
    {
        info->quiet_parse= 0;
        if(check_col(info->pinfo->cinfo, COL_INFO))
            col_add_fstr(info->pinfo->cinfo, COL_INFO, "%s (type %u, ID %u)", name, type, id);

        /* Show a dissection tree node for the standard LLRP header information */
        item= proto_tree_add_item(proto_tree_get_root(info->tree[0]), proto_epc_llrp, info->tvb, 0, -1, FALSE);
        proto_item_append_text(item, ": %s (ID %u)", name, id);
        tree= proto_item_add_subtree(item, ett_llrp_message);      

        /* Display the standard header data */
        proto_tree_add_uint(tree, hf_llrp_message_version, info->tvb, 0, 1, version);
        proto_tree_add_uint(tree, hf_llrp_message_type, info->tvb, 0, 2, type);
        proto_tree_add_uint(tree, hf_llrp_message_length, info->tvb, 2, 4, length);
        proto_tree_add_uint(tree, hf_llrp_message_id, info->tvb, 6, 4, id);
    }

    llrp_ws_DescendParseTree(ctxt, info, tree);
    return 1; /* continue parsing */
}     

void llrp_ws_HandleField(void *context, const unsigned short field_index, const unsigned char type,
 const char *name, const unsigned long bitlength, const unsigned char *data,
 t_llrp_enumeration *enumeration)
{
    proto_tree *tree= NULL;
    const char *enumeration_name;
    unsigned short enumeration_value;
    t_llrp_parse_context *ctxt= (t_llrp_parse_context *) context;
    t_llrp_parse_info *info= (t_llrp_parse_info *) ctxt->data;
    unsigned long bytelength= (bitlength/8)+((bitlength%8) ? 1 : 0);
    unsigned long total_length= bytelength+(LLRP_FIELDTYPE_IS_VARIABLE(type) ? 2 : 0);
    unsigned long count= 0;

    #ifdef LLRP_DEBUG
    g_warning("llrp_ws_HandleField (type %d)", type);
    #endif /* LLRP_DEBUG */

    if(ctxt->depth> 0 && !info->quiet_parse)
    {
        proto_item *item;
        proto_tree *parent_tree= info->tree[(ctxt->depth)-1];

        if(parent_tree!= NULL)
        {
            item= proto_tree_add_uint_format_value(parent_tree, hf_llrp_message_field, info->tvb,
             llrp_buffer_offset-total_length, total_length, type, "%s (%s)", name,
             llrp_field_type_to_name(type));
            tree= proto_item_add_subtree(item, ett_llrp_field);
            proto_tree_add_uint_format_value(tree, hf_llrp_field_type, info->tvb,
             llrp_buffer_offset-total_length, total_length, type, "%s (%u)",
             llrp_field_type_to_name(type), type);
            if(LLRP_FIELDTYPE_IS_VARIABLE(type))
            {
                count= bitlength/llrp_variable_field_bitlength[LLRP_FIELDTYPE_INDEX_VARIABLE(type)];
                proto_tree_add_uint(tree, hf_llrp_field_count, info->tvb,
                 llrp_buffer_offset-total_length, 2, count);                 
            }
            proto_tree_add_uint(tree, hf_llrp_field_bitlength, info->tvb,
             llrp_buffer_offset-total_length, total_length, bitlength);
            switch(type)
            {
                case LLRP_FIELDTYPE_u1:
                    proto_tree_add_uint(tree, hf_llrp_field_value_u1, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, *data);
                    enumeration_value= *data;
                    break;
                case LLRP_FIELDTYPE_u2:
                    proto_tree_add_uint(tree, hf_llrp_field_value_u2, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, *data);
                    enumeration_value= *data;
                    break;
                case LLRP_FIELDTYPE_u8:
                    proto_tree_add_uint_format_value(tree, hf_llrp_field_value_u8, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, *data, "0x%02x (%u)", *data, *data);
                    enumeration_value= *data;
                    break;
                case LLRP_FIELDTYPE_s8:
                    proto_tree_add_int_format_value(tree, hf_llrp_field_value_s8, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, *data, "0x%02x (%d)", *data, *data);
                    enumeration_value= *data;
                    break;
                case LLRP_FIELDTYPE_u16:
                {
                    unsigned short value= pntohs(((unsigned short*)data));
                    proto_tree_add_uint_format_value(tree, hf_llrp_field_value_u16, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%04x (%u)", value, value);
                    enumeration_value= value;
                    break;
                }
                case LLRP_FIELDTYPE_s16:
                {
                    unsigned short value= pntohs(((unsigned short*)data));
                    proto_tree_add_int_format_value(tree, hf_llrp_field_value_s16, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%04x (%d)", value, value);
                    enumeration_value= value;
                    break;
                }
                case LLRP_FIELDTYPE_u32:
                {
                    unsigned long value= pntohl(((unsigned long*)data));
                    proto_tree_add_uint_format_value(tree, hf_llrp_field_value_u32, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%08x (%u)", value, value);
                    break;
                }
                case LLRP_FIELDTYPE_s32:
                {
                    unsigned long value= pntohl(((unsigned long*)data));
                    proto_tree_add_int_format_value(tree, hf_llrp_field_value_s32, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%08x (%d)", value, value);
                    break;
                }
                case LLRP_FIELDTYPE_u64:
                {
                    guint64 value= pntoh64((guint64*)data);
                    proto_tree_add_uint64_format_value(tree, hf_llrp_field_value_u64, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%016x(%u)", value, value);
                    break;
                }
                case LLRP_FIELDTYPE_s64:
                {
                    guint64 value= pntoh64((guint64*)data);
                    proto_tree_add_int64_format_value(tree, hf_llrp_field_value_s64, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, value, "0x%016x (%u)", value, value);
                    break;
                }
                case LLRP_FIELDTYPE_utf8v:
                {
                    char *string;
                    string= (char *) malloc(bytelength+3);
                    if(string!= NULL)
                    {
                        memcpy(string+1, data, bytelength);
                        string[0]= '"';
                        string[bytelength+1]= '"';
                        string[bytelength+2]= '\0';
                        proto_tree_add_string(tree, hf_llrp_field_value_variable, info->tvb,
                         llrp_buffer_offset-bytelength, bytelength, string);
                        free(string);
                    }
                    break;
                }
                case LLRP_FIELDTYPE_u8v:
                case LLRP_FIELDTYPE_s8v:
                {
                    char *string;
                    string= (char *) malloc(6*count);
                    if(string!= NULL)
                    {
                        unsigned short idx;
                        string[0]= '\0';
                        for(idx= 0; idx< count; idx++)
                        {
                            sprintf(string+strlen(string), "%s%d",
                             (idx>0) ? ", " : "", data[idx]);
                        }
                        proto_tree_add_string(tree, hf_llrp_field_value_variable, info->tvb,
                         llrp_buffer_offset-bytelength, bytelength, string);
                        free(string);
                    }
                    break;
                }                
                case LLRP_FIELDTYPE_u16v:
                case LLRP_FIELDTYPE_s16v:
                {
                    char *string;
                    string= (char *) malloc(8*count);
                    if(string!= NULL)
                    {
                        unsigned short idx;
                        string[0]= '\0';
                        for(idx= 0; idx< count; idx++)
                        {
                            sprintf(string+strlen(string), "%s%d",
                             (idx>0) ? ", " : "", pntohs(&data[idx*2]));
                        }
                        proto_tree_add_string(tree, hf_llrp_field_value_variable, info->tvb,
                         llrp_buffer_offset-bytelength, bytelength, string);
                        free(string);
                    }
                    break;
                }
                case LLRP_FIELDTYPE_u32v:
                case LLRP_FIELDTYPE_s32v:
                {
                    char *string;
                    string= (char *) malloc(13*count);
                    if(string!= NULL)
                    {
                        unsigned short idx;
                        string[0]= '\0';
                        for(idx= 0; idx< count; idx++)
                        {
                            sprintf(string+strlen(string), "%s%d",
                             (idx>0) ? ", " : "", pntohl(&data[idx*4]));
                        }
                        proto_tree_add_string(tree, hf_llrp_field_value_variable, info->tvb,
                         llrp_buffer_offset-bytelength, bytelength, string);
                        free(string);
                    }
                    break;
                }
                case LLRP_FIELDTYPE_u64v:
                case LLRP_FIELDTYPE_s64v:
                {
                    char *string;
                    string= (char *) malloc(23*count);
                    if(string!= NULL)
                    {
                        unsigned short idx;
                        string[0]= '\0';
                        for(idx= 0; idx< count; idx++)
                        {
                            sprintf(string+strlen(string), "%s%d",
                             (idx>0) ? ", " : "", pntoh64(&data[idx*8]));
                        }
                        proto_tree_add_string(tree, hf_llrp_field_value_variable, info->tvb,
                         llrp_buffer_offset-bytelength, bytelength, string);
                        free(string);
                    }
                    break;
                }
                default:
                    break;
            }

            if(enumeration!= NULL)
            {
                enumeration_name= llrp_enumeration_to_name(enumeration, enumeration_value);
                if(enumeration_name!= NULL)
                {
                    proto_tree_add_string(tree, hf_llrp_field_enumeration, info->tvb,
                     llrp_buffer_offset-bytelength, bytelength, enumeration_name);
                }
            }
        }
    }
}

void llrp_ws_HandleParameterStart(void *context, const unsigned short type, const char *name,
 const unsigned short length)
{
    proto_tree *tree= NULL;
    t_llrp_parse_context *ctxt= (t_llrp_parse_context *) context;
    t_llrp_parse_info *info= (t_llrp_parse_info *) ctxt->data;

    #ifdef LLRP_DEBUG
    g_warning("llrp_ws_HandleParameterStart (type %d)", type);
    #endif /* LLRP_DEBUG */

    if(ctxt->depth> 0 && !info->quiet_parse)
    {
        proto_item *item;
        proto_tree *parent_tree= info->tree[(ctxt->depth)-1];

        if(parent_tree!= NULL)
        {
            if(type<= 127)
            {
                item= proto_tree_add_uint_format_value(parent_tree, hf_llrp_message_parm, info->tvb,
                 llrp_buffer_offset-1, length+1, type, "%s (type %u)", name, type);
                tree= proto_item_add_subtree(item, ett_llrp_parameter);
                proto_tree_add_uint_format_value(tree, hf_llrp_parameter_type, info->tvb,
                 llrp_buffer_offset-1, 1, type, "%u (TV-encoded)", type);
            }
            else
            {
                item= proto_tree_add_uint_format_value(parent_tree, hf_llrp_message_parm, info->tvb,
                 llrp_buffer_offset-4, length+4, type, "%s (type %u)", name, type);
                tree= proto_item_add_subtree(item, ett_llrp_parameter);
                proto_tree_add_uint_format_value(tree, hf_llrp_parameter_type, info->tvb,
                 llrp_buffer_offset-4, 2, type, "%u (TLV-encoded)", type);
                proto_tree_add_uint(tree, hf_llrp_parameter_length, info->tvb, llrp_buffer_offset-2, 2, length);
            }
        }
    }

    llrp_ws_DescendParseTree(ctxt, info, tree);
}

void llrp_ws_HandleParameterFinished(void *context, const unsigned short type, const char *name,
 const unsigned short length)
{
    t_llrp_parse_context *ctxt= (t_llrp_parse_context *) context;
    t_llrp_parse_info *info= (t_llrp_parse_info *) ctxt->data;

    llrp_ws_AscendParseTree(ctxt, info);
}

void llrp_ws_HandleParseError(void *context, const unsigned char code, const unsigned short item,
 const char *format, ...)
{
    t_llrp_parse_context *ctxt= (t_llrp_parse_context *) context;
    t_llrp_parse_info *info= (t_llrp_parse_info *) ctxt->data;
    va_list argList;
    char message[100];

    if(ctxt->depth> 0 && !info->quiet_parse)
    {
        proto_tree *parent_tree= info->tree[(ctxt->depth)-1];
        if(parent_tree!= NULL)
        {
            va_start(argList, format);
            _vsnprintf(message, 100, format, argList);
            proto_tree_add_text(parent_tree, info->tvb, 0, 0, message);
            va_end(argList);
        }
    }
}

#define LLRP_DEBUG_MAX_STRING_LENGTH 160 /* characters */
void llrp_ws_HandleDebugMessage(void *context, const char *format, ...)
{
    #ifdef LLRP_DEBUG
    va_list argList;
    char message[LLRP_DEBUG_MAX_STRING_LENGTH+1];

    va_start(argList, format);
    _vsnprintf(message, LLRP_DEBUG_MAX_STRING_LENGTH, format, argList);
    message[LLRP_DEBUG_MAX_STRING_LENGTH]= '\0';
    g_warning(message);
    va_end(argList);
    #endif /* LLRP_DEBUG */
}

int llrp_ws_HandleBufferFill(void *context, t_llrp_buffer *buffer, const unsigned long length)
{
    #ifdef LLRP_DEBUG
    g_warning("llrp_ws_HandleBufferFill: request for fill of %lu bytes", length);
    #endif /* LLRP_DEBUG */
    return 0; /* can't fill the buffer any more... */
}

/* --------------------------------------------------------------------------------------- */

static t_llrp_parse_validator *llrp_parse_validator_list[]= { &llrp_v1_0_parse_validator };

static t_llrp_parse_context parse_context = {
    0 /*depth*/, llrp_parse_validator_list, sizeof(llrp_parse_validator_list)/sizeof(t_llrp_parse_validator *),
    llrp_ws_HandleBufferFill, llrp_ws_HandleMessageStart, NULL /*message finished*/,
    llrp_ws_HandleField, NULL /*field complete*/, llrp_ws_HandleParameterStart,
    llrp_ws_HandleParameterFinished, NULL /*all parameters complete*/, llrp_ws_HandleParseError,
    llrp_ws_HandleDebugMessage, (void *) &llrp_parse_info
};

static guint get_epc_llrp_message_len(packet_info *pinfo, tvbuff_t *tvb, int offset)
{
    guint length;
    /* Peek into the header to determine the total message length */
    length= (guint) tvb_get_ntohl(tvb, offset+2); 
    g_warning("get_epc_llrp_message_len: offset=%d, length=%u", offset, length);
    return length;
}

static int dissect_epc_llrp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{   
    /* Make the protocol column in the packet list display the protocol name */
    if(check_col(pinfo->cinfo, COL_PROTOCOL))
        col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_SHORT_DESCRIPTION_LLRP);

    /* Start with a clean info column */
    if(check_col(pinfo->cinfo, COL_INFO))
        col_clear(pinfo->cinfo, COL_INFO);

    if(tree)
    {
        memset(&llrp_parse_info, 0, sizeof(llrp_parse_info));

        /* Dissect the contents of the message */
        llrp_parse_info.tree[0]= tree;
        llrp_parse_info.tvb= tvb;
        llrp_parse_info.pinfo= pinfo;
        llrp_buffer_offset= 0;        
        llrp_ParseMessage(&parse_context, tvb);
    }

    return 0;
}

static int dissect_epc_llrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    tcp_dissect_pdus(tvb, pinfo, tree, TRUE, LLRP_HEADER_LENGTH, get_epc_llrp_message_len,
     dissect_epc_llrp_message);
    return 0;
}

void proto_reg_handoff_epc_llrp(void)
{
    static int llrp_prefs_initialized = FALSE;
    static dissector_handle_t epc_llrp_handle;

    if(!llrp_prefs_initialized)
    {
        epc_llrp_handle = create_dissector_handle(dissect_epc_llrp, proto_epc_llrp);
        llrp_prefs_initialized = TRUE;
    }
    else
    {
        dissector_delete("tcp.port", TCP_PORT_EPC_LLRP, epc_llrp_handle);
    }

    /* The only binding for LLRP is TCP */
    dissector_add("tcp.port", TCP_PORT_EPC_LLRP, epc_llrp_handle);
}    

/* Filtering engine registration */
void proto_register_epc_llrp(void)
{
    /* Register the LLRP protocol */
    if(proto_epc_llrp == -1)
    {
        proto_epc_llrp = proto_register_protocol(PROTO_DESCRIPTION_LLRP,
         PROTO_SHORT_DESCRIPTION_LLRP, PROTO_NAME_LLRP);
    }

    proto_register_field_array(proto_epc_llrp, hf_llrp_header, array_length(hf_llrp_header));
    proto_register_field_array(proto_epc_llrp, hf_llrp_field, array_length(hf_llrp_field));
    proto_register_field_array(proto_epc_llrp, hf_llrp_parameter, array_length(hf_llrp_parameter));
    proto_register_subtree_array(ett_llrp, array_length(ett_llrp));

    /* Allow dissector to find be found by name. */
    new_register_dissector(PROTO_NAME_LLRP, dissect_epc_llrp, proto_epc_llrp);

    /* Register a list of settable preferences for the LLRP dissector */
    /*prefs_register_epc_llrp();*/
}

#if 0
static void prefs_register_epc_llrp()
{
    module_t *diameter_module;

    /* Register a configuration option for port */
    diameter_module= prefs_register_protocol(proto_diameter, proto_reg_handoff_diameter);

    /* Register a configuration option for Diameter version */
    prefs_register_enum_preference(diameter_module, "version", "Diameter version",
     "Standard version used for decoding", (gint *)&gbl_version, options, FALSE);

    /* Allow specification of an alternate TCP port number */
    prefs_register_uint_preference(diameter_module, "tcp.port", "Diameter TCP Port",
     "Set the TCP port for Diameter messages", 10, &gbl_diameterTcpPort);

    /* Desegmentation */
    prefs_register_bool_preference(diameter_module, "desegment",
     "Reassemble Diameter messages\nspanning multiple TCP segments",
     "Whether the Diameter dissector should reassemble messages spanning multiple TCP segments."
     " To use this option, you must also enable \"Allow subdissectors to reassemble TCP "
     "streams\" in the TCP protocol settings.", &gbl_diameter_desegment);

    /* Allow zero as valid application ID */
    prefs_register_bool_preference(diameter_module, "allow_zero_as_app_id",
     "Allow 0 as valid application ID", "If set, the value 0 (zero) can be used as a valid "
     "application ID. This is used in experimental cases.", &allow_zero_as_app_id);
} /* prefs_register_epc_llrp */
#endif