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

/* packet-cfdp.c
 * Routines for CCSDS File Delivery Protocol (CFDP) dissection
 * Copyright 2013, Juan Antonio Montesinos juan.mondl@gmail.com
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>


/* The CFDP standard can be found here:
 * http://public.ccsds.org/publications/archive/727x0b4.pdf
 *
 * The Store and Forward Overlay Operations are not included.
 */

void proto_register_cfdp(void);
void proto_reg_handoff_cfdp(void);

/* Initialize the protocol and registered fields */
static int proto_cfdp = -1;
static int hf_cfdp_version = -1;
static int hf_cfdp_pdu_type = -1;
static int hf_cfdp_direction = -1;
static int hf_cfdp_trans_mode = -1;
static int hf_cfdp_crc_flag = -1;
static int hf_cfdp_res1 = -1;
static int hf_cfdp_data_length = -1;
static int hf_cfdp_res2 = -1;
static int hf_cfdp_entid_length = -1;
static int hf_cfdp_res3 = -1;
static int hf_cfdp_transeqnum_length = -1;
static int hf_cfdp_srcid = -1;
static int hf_cfdp_transeqnum = -1;
static int hf_cfdp_dstid = -1;
static int hf_cfdp_file_directive_type = -1;
static int hf_cfdp_file_data_offset = -1;
static int hf_cfdp_progress = -1;
static int hf_cfdp_dir_code_ack = -1;
static int hf_cfdp_dir_subtype_ack = -1;
static int hf_cfdp_condition_code = -1;
static int hf_cfdp_spare_one = -1;
static int hf_cfdp_spare_one_2 = -1;
static int hf_cfdp_spare_two = -1;
static int hf_cfdp_spare_four = -1;
static int hf_cfdp_spare_five = -1;
static int hf_cfdp_spare_seven = -1;
static int hf_cfdp_spare_seven_2 = -1;
static int hf_cfdp_trans_stat_ack = -1;
static int hf_cfdp_file_checksum = -1;
static int hf_cfdp_file_size = -1;
static int hf_cfdp_end_system_stat = -1;
static int hf_cfdp_delivery_code = -1;
static int hf_cfdp_file_stat = -1;
static int hf_cfdp_segment_control = -1;
static int hf_cfdp_src_file_name = -1;
static int hf_cfdp_dst_file_name = -1;
static int hf_cfdp_first_file_name = -1;
static int hf_cfdp_second_file_name = -1;
static int hf_cfdp_nak_st_scope = -1;
static int hf_cfdp_nak_sp_scope = -1;
static int hf_cfdp_crc = -1;
static int hf_cfdp_action_code = -1;
static int hf_cfdp_status_code_1 = -1;
static int hf_cfdp_status_code_2 = -1;
static int hf_cfdp_status_code_3 = -1;
static int hf_cfdp_status_code_4 = -1;
static int hf_cfdp_status_code_5 = -1;
static int hf_cfdp_status_code_6 = -1;
static int hf_cfdp_status_code_7 = -1;
static int hf_cfdp_status_code_8 = -1;
static int hf_cfdp_handler_code = -1;
static int hf_cfdp_trans_mode_msg = -1;
static int hf_cfdp_proxy_msg_type = -1;
static int hf_cfdp_proxy_segment_control = -1;
static int hf_cfdp_proxy_delivery_code = -1;
static int hf_cfdp_response_req = -1;
static int hf_cfdp_directory_name = -1;
static int hf_cfdp_directory_file_name = -1;
static int hf_cfdp_listing_resp_code = -1;
static int hf_cfdp_report_file_name = -1;
static int hf_cfdp_trans_stat = -1;
static int hf_cfdp_trans_stat_2 = -1;
static int hf_cfdp_rep_resp_code = -1;
static int hf_cfdp_suspension_ind = -1;
static int hf_cfdp_tlv_len = - 1;

/* Generated from convert_proto_tree_add_text.pl */
static int hf_cfdp_filestore_message = -1;
static int hf_cfdp_entity = -1;
static int hf_cfdp_message_to_user = -1;
static int hf_cfdp_flow_label = -1;
static int hf_cfdp_segment_requests = -1;
static int hf_cfdp_user_data = -1;

/* Initialize the subtree pointers */
static gint ett_cfdp = -1;
static gint ett_cfdp_header = -1;
static gint ett_cfdp_file_directive_header = -1;
static gint ett_cfdp_file_data_header = -1;
static gint ett_cfdp_fault_location = -1;
static gint ett_cfdp_crc = -1;
static gint ett_cfdp_filestore_req = -1;
static gint ett_cfdp_filestore_resp = -1;
static gint ett_cfdp_msg_to_user = -1;
static gint ett_cfdp_fault_hdl_overr = -1;
static gint ett_cfdp_flow_label = -1;

static expert_field ei_cfdp_bad_length = EI_INIT;


static dissector_handle_t cfdp_handle;

/* Some parameters */
#define CFDP_HEADER_FIXED_FIELDS_LEN 4
#define CFDP_APID 2045

/* Bitmask for the first byte of the Header */
#define HDR_VERSION_CFDP    0xe0
#define HDR_TYPE_CFDP       0x10
#define HDR_DIR             0x08
#define HDR_TMODE           0x04
#define HDR_CRCF            0x02
#define HDR_RES1            0x01

/* Bitmask for the second byte of the Header */
#define HDR_RES2            0x80
#define HDR_LEN_ENT_ID      0x70
#define HDR_RES3            0x08
#define HDR_LEN_TSEQ_NUM    0x07

/* File Directive Codes */
#define EOF_PDU          4
#define FINISHED_PDU     5
#define ACK_PDU          6
#define METADATA_PDU     7
#define NAK_PDU          8
#define PROMPT_PDU       9
#define KEEP_ALIVE_PDU  12

/* TLV Types */
#define FILESTORE_REQ    0
#define FILESTORE_RESP   1
#define MSG_TO_USER      2
#define FAULT_HDL_OVERR  4
#define FLOW_LABEL       5
#define FAULT_LOCATION   6

/* ID for reserved CFDP Messages  */
#define CFDP_MSG_TO_USER 0x63666470

/* Proxy Operations Message Types */
#define PROXY_PUT_REQ           0x00
#define PROXY_MSG_TO_USER       0x01
#define PROXY_FILESTORE_REQ     0x02
#define PROXY_FAULT_HDL_OVERR   0x03
#define PROXY_TRANS_MODE        0x04
#define PROXY_FLOW_LABEL        0x05
#define PROXY_SEGMENT_CONTROL   0x06
#define PROXY_PUT_RESP          0x07
#define PROXY_FILESTORE_RESP    0x08
#define PROXY_PUT_CANCEL        0x09
#define ORIG_TRANS_ID           0x0A
#define DIRECTORY_LIST_REQ      0x10
#define DIRECTORY_LIST_RESP     0x11
#define REMOTE_STAT_REP_REQ     0x20
#define REMOTE_STAT_REP_RESP    0x21
#define REMOTE_SUSPEND_REQ      0x30
#define REMOTE_SUSPEND_RESP     0x31
#define REMOTE_RESUME_REQ       0x38
#define REMOTE_RESUME_RESP      0x39

/* PDU Type */
static const value_string cfdp_pdu_type[] = {
    { 0, "File Directive" },
    { 1, "File Data" },
    { 0, NULL }
};

/* PDU Direction */
static const value_string cfdp_direction[] = {
    { 0, "Toward file receiver" },
    { 1, "Toward file sender" },
    { 0, NULL }
};

/* Transmission mode */
static const value_string cfdp_trans_mode[] = {
    { 0, "Acknowledged" },
    { 1, "Unacknowledged" },
    { 0, NULL }
};

/* CRC */
static const value_string cfdp_crc_flag[] = {
    { 0, "CRC not present" },
    { 1, "CRC present" },
    { 0, NULL }
};

/* File Directive PDU Type */
static const value_string cfdp_file_directive_type[] = {
    {  4, "EOF PDU"},
    {  5, "Finished PDU"},
    {  6, "ACK PDU"},
    {  7, "Metadata PDU"},
    {  8, "NACK PDU"},
    {  9, "Prompt PDU"},
    { 12, "Keep Alive PDU"},
    {  0, NULL}
};

/* Condition codes */
static const value_string cfdp_condition_codes[] = {
    {  0, "No error"},
    {  1, "Positive ACK limit reached"},
    {  2, "Keep alive limit reached"},
    {  3, "Invalid transmission mode"},
    {  4, "Filestore rejection"},
    {  5, "File checksum failure"},
    {  6, "File size error"},
    {  7, "NAK limit reached"},
    {  8, "Inactivity detected"},
    {  9, "Check limit reached"},
    { 14, "Suspend.request received"},
    { 15, "Cancel.request received"},
    {  0, NULL }
};

/* Transaction status */
static const value_string cfdp_trans_stat_ack[] = {
    { 0, "Undefined" },
    { 1, "Active" },
    { 2, "Terminated" },
    { 3, "Unrecognized" },
    { 0, NULL }
};

/* End system status */
static const value_string cfdp_end_system_stat[] = {
    { 0, "Generated by Waypoint" },
    { 1, "Generated by End System" },
    { 0, NULL }
};

/* Delivery code */
static const value_string cfdp_delivery_code[] = {
    { 0, "Data Complete" },
    { 1, "Data incomplete" },
    { 0, NULL }
};

/* Filestore operations action code */
static const value_string cfdp_action_code[] = {
    { 0, "Create File" },
    { 1, "Delete File" },
    { 2, "Rename File" },
    { 3, "Append File" },
    { 4, "Replace File" },
    { 5, "Create Directory" },
    { 6, "Remove Directory" },
    { 7, "Deny File (delete if present)" },
    { 8, "Deny Directory (remove if present)" },
    { 0, NULL }
};

/* Filestore operations status codes */
static const value_string cfdp_status_code_1[] = {
    { 0, "Successful" },
    { 1, "Create not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_2[] = {
    { 0, "Successful" },
    { 1, "File does not exist" },
    { 2, "Delete not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_3[] = {
    { 0, "Successful" },
    { 1, "Old File Name does not exist" },
    { 2, "New File Name already exists" },
    { 3, "Rename not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_4[] = {
    { 0, "Successful" },
    { 1, "File Name 1 does not exist" },
    { 2, "File Name 2 does not exist" },
    { 3, "Append not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_5[] = {
    { 0, "Successful" },
    { 1, "File Name 1 does not exist" },
    { 2, "File Name 2 does not exist" },
    { 3, "Replace not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_6[] = {
    { 0, "Successful" },
    { 1, "Directory cannot be created" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_7[] = {
    { 0, "Successful" },
    { 1, "Directory does not exist" },
    { 2, "Delete not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

static const value_string cfdp_status_code_8[] = {
    { 0, "Successful" },
    { 1, "Delete not allowed" },
    { 8, "Not performed" },
    { 0, NULL }
};

/* Finished PDU File Status */
static const value_string cfdp_file_stat[] = {
    { 0, "Delivery file discarded deliberately" },
    { 1, "Delivery file discarded due to filestore rejection" },
    { 2, "Delivery file retained in filestore successfully" },
    { 3, "Delivery file status unreported" },
    { 0, NULL }
};

/* Segmentation control */
static const value_string cfdp_segment_control[] = {
    { 0, "Record boundaries respected" },
    { 1, "Record boundaries not respected" },
    { 0, NULL }
};

/* Fault handler override Handler code*/
static const value_string cfdp_handler_codes[] = {
    { 1, "issue Notice of Cancellation" },
    { 2, "issue Notice of Suspension" },
    { 3, "Ignore error" },
    { 4, "Abandon transaction" },
    { 0, NULL }
};

/* Type of Proxy message */
static const value_string cfdp_proxy_msg_type[] = {
    { 0x00, "Proxy Put Request"},
    { 0x01, "Proxy Message To User"},
    { 0x02, "Proxy Filestore Request"},
    { 0x03, "Proxy Fault Handler Override"},
    { 0x04, "Proxy Transmission Mode"},
    { 0x05, "Proxy Flow Label"},
    { 0x06, "Proxy Segmentation Control"},
    { 0x07, "Proxy Put Response"},
    { 0x08, "Proxy Filestore Response"},
    { 0x09, "Proxy Put Cancel"},
    { 0x0A, "Originating Transaction ID"},
    { 0x10, "Directory Listing Request"},
    { 0x11, "Directory Listing Response"},
    { 0x20, "Remote Status Report Request"},
    { 0x21, "Remote Status Report Response"},
    { 0x30, "Remote Suspend Request"},
    { 0x31, "Remote Suspend Response"},
    { 0x38, "Remote Resume Request"},
    { 0x39, "Remote Resume Response"},
    { 0, NULL }
};
static value_string_ext cfdp_proxy_msg_type_ext = VALUE_STRING_EXT_INIT(cfdp_proxy_msg_type);

/* Prompt PDU Response required */
static const value_string cfdp_response_req[] = {
    { 0, "NAK" },
    { 1, "Keep Alive" },
    { 0, NULL }
};

/* Listing response code */
static const value_string cfdp_listing_resp_code[] = {
    { 0, "Successful" },
    { 1, "Unsuccessful" },
    { 0, NULL }
};

/* Report response code */
static const value_string cfdp_rep_resp_code[] = {
    { 0, "Unsuccessful" },
    { 1, "Successful" },
    { 0, NULL }
};

/* Suspension indication */
static const value_string cfdp_suspension_ind[] = {
    { 0, "Not Suspended" },
    { 1, "Suspended" },
    { 0, NULL }
};

/* File Directive codes */
static const value_string cfdp_directive_codes[] = {
    { 0x04, "EOF" },
    { 0x05, "Finished" },
    { 0x06, "ACK" },
    { 0x07, "Metadata" },
    { 0x08, "NAK" },
    { 0x09, "Prompt" },
    { 0x0C, "Keep Alive" },
    { 0, NULL }
};

/* Dissect the Source Entity ID field */
static void
dissect_cfdp_src_entity_id(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint8 len_ent_id)
{
    if(len_ent_id > 0 && len_ent_id <= 8){
        proto_tree_add_item(tree, hf_cfdp_srcid, tvb, offset, len_ent_id, ENC_BIG_ENDIAN);
    }
    else{
        proto_tree_add_expert_format(tree, pinfo, &ei_cfdp_bad_length, tvb, offset, 0, "Wrong length for the entity ID");
    }
}

/* Dissect the Destination Entity ID field */
static void
dissect_cfdp_dst_entity_id(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint8 len_ent_id)
{
    if(len_ent_id > 0 && len_ent_id <= 8){
        proto_tree_add_item(tree, hf_cfdp_dstid, tvb, offset, len_ent_id, ENC_BIG_ENDIAN);
    }
    else{
        proto_tree_add_expert_format(tree, pinfo, &ei_cfdp_bad_length, tvb, offset, 0, "Wrong length for the entity ID");
    }
}

/* Dissect the Transaction Sequence Number field */
static void
dissect_cfdp_tseq_num(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint8 len_tseq_num)
{
    if(len_tseq_num > 0 && len_tseq_num <= 8){
        proto_tree_add_item(tree, hf_cfdp_transeqnum, tvb, offset, len_tseq_num, ENC_BIG_ENDIAN);
    }
    else{
        proto_tree_add_expert_format(tree, pinfo, &ei_cfdp_bad_length, tvb, offset, 0, "Wrong length for transaction sequence number");
    }
}

/* Dissect the Filestore Request TLV */
static guint32 dissect_cfdp_filestore_req_tlv(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint8 tlv_len;

    guint32 offset = ext_offset;

    /* Get field length */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;
    if(tlv_len > 0){
        proto_tree  *cfdp_filestore_req_tree;
        guint8 aux_byte;

        /* Create a TLV subtree */
        cfdp_filestore_req_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
            ett_cfdp_filestore_req, NULL, "Filestore Request TLV");

        proto_tree_add_uint(cfdp_filestore_req_tree, hf_cfdp_tlv_len, tvb, offset-1, 1, tlv_len);

        aux_byte = tvb_get_guint8(tvb, offset);
        proto_tree_add_uint(cfdp_filestore_req_tree, hf_cfdp_action_code, tvb, offset, 1, aux_byte);
        proto_tree_add_uint(cfdp_filestore_req_tree, hf_cfdp_spare_four, tvb, offset, 1, aux_byte);
        offset += 1;

        aux_byte = tvb_get_guint8(tvb, offset);
        offset += 1;
        proto_tree_add_item(cfdp_filestore_req_tree, hf_cfdp_first_file_name, tvb, offset, aux_byte, ENC_ASCII|ENC_NA);
        offset += aux_byte;

        aux_byte = tvb_get_guint8(tvb, offset);
        offset += 1;
        if(aux_byte > 0){
            proto_tree_add_item(cfdp_filestore_req_tree, hf_cfdp_second_file_name, tvb, offset, aux_byte, ENC_ASCII|ENC_NA);
            offset += aux_byte;
        }
    }

    return offset;
}

/* Dissect the Filestore Response TLV */
static guint32 dissect_cfdp_filestore_resp_tlv(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint8 tlv_len;

    guint32 offset = ext_offset;

    /* Get field length */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;
    if(tlv_len > 0){
        proto_tree  *cfdp_filestore_resp_tree;
        guint8 aux_byte;

        /* Create a subtree */
        cfdp_filestore_resp_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                        ett_cfdp_filestore_resp, NULL, "Filestore Response TLV");

        proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_tlv_len, tvb, offset-1, 1, tlv_len);

        aux_byte = tvb_get_guint8(tvb, offset);
        proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_action_code, tvb, offset, 1, aux_byte);
        switch((aux_byte & 0xF0) >> 4){
            case 0:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_1, tvb, offset, 1, aux_byte);
                break;
            case 1:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_2, tvb, offset, 1, aux_byte);
                break;
            case 2:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_3, tvb, offset, 1, aux_byte);
                break;
            case 3:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_4, tvb, offset, 1, aux_byte);
                break;
            case 4:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_5, tvb, offset, 1, aux_byte);
                break;
            case 5:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_6, tvb, offset, 1, aux_byte);
                break;
            case 6:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_7, tvb, offset, 1, aux_byte);
                break;
            case 7: case 8:
                proto_tree_add_uint(cfdp_filestore_resp_tree, hf_cfdp_status_code_8, tvb, offset, 1, aux_byte);
                break;

            default:
                break;
        }
        offset += 1;

        aux_byte = tvb_get_guint8(tvb, offset);
        offset += 1;
        proto_tree_add_item(cfdp_filestore_resp_tree, hf_cfdp_first_file_name, tvb, offset, aux_byte, ENC_ASCII|ENC_NA);
        offset += aux_byte;

        aux_byte = tvb_get_guint8(tvb, offset);
        offset += 1;
        if(aux_byte > 0){
            proto_tree_add_item(cfdp_filestore_resp_tree, hf_cfdp_second_file_name, tvb, offset, aux_byte, ENC_ASCII|ENC_NA);
            offset += aux_byte;
        }
        /* Filestore Message */
        aux_byte = tvb_get_guint8(tvb, offset);
        offset += 1;
        if(aux_byte > 0){
            proto_tree_add_item(cfdp_filestore_resp_tree, hf_cfdp_filestore_message, tvb, offset, tlv_len, ENC_NA);
            offset += aux_byte;
        }
    }

    return offset;
}

/* Dissect the Fault Location TLV */
static guint32 dissect_cfdp_fault_location_tlv(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint8 tlv_len;

    guint32 offset = ext_offset;

    /* Get field length */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;
    if(tlv_len > 0){
        proto_tree  *cfdp_fault_location_tree;

        /* Create a subtree */
        cfdp_fault_location_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                                        ett_cfdp_fault_location, NULL, "Fault location TLV");

        proto_tree_add_uint(cfdp_fault_location_tree, hf_cfdp_tlv_len, tvb, offset-1, 1, tlv_len);

        proto_tree_add_item(cfdp_fault_location_tree, hf_cfdp_entity, tvb, offset, tlv_len, ENC_NA);
        offset += tlv_len;
    }

    return offset;
}

/* Dissect the Message to User TLV */
static guint32 dissect_cfdp_msg_to_user_tlv(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset){

    guint8 aux_byte, tlv_type, tlv_len;
    proto_tree  *cfdp_msg_to_user_tree;

    guint32 offset = ext_offset;
    guint32 msg_to_user_id;
    int len_ent_id;
    int len_tseq_num;

    /* Get tlv len */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;

    /* Create a subtree */
    cfdp_msg_to_user_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                                    ett_cfdp_filestore_resp, NULL, "Message To User TLV");

    proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_tlv_len, tvb, offset-1, 1, tlv_len);

    msg_to_user_id = tvb_get_ntohl(tvb, offset);
    /* Proxy operations */
    if(msg_to_user_id == CFDP_MSG_TO_USER){
        offset += 4;
        tlv_type =  tvb_get_guint8(tvb, offset);
        proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_proxy_msg_type, tvb, offset, 1, tlv_type);
        offset += 1;
        switch(tlv_type){

            case PROXY_PUT_REQ:
                tlv_len = tvb_get_guint8(tvb, offset);
                offset += 1;
                dissect_cfdp_dst_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, tlv_len);
                offset += tlv_len;

                tlv_len = tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_src_file_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;

                tlv_len = tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_dst_file_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;

                break;

            case PROXY_MSG_TO_USER:
                tlv_len = tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_message_to_user, tvb, offset, tlv_len, ENC_NA);
                break;

            case PROXY_FILESTORE_REQ:
                offset = dissect_cfdp_filestore_req_tlv(tvb, cfdp_msg_to_user_tree, offset);
                break;

            case PROXY_FAULT_HDL_OVERR:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_handler_code, tvb, offset, 1, aux_byte);
                offset += 1;
                break;

            case PROXY_TRANS_MODE:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_seven_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_trans_mode_msg, tvb, offset, 1, aux_byte);
                offset += 1;
                break;

            case PROXY_FLOW_LABEL:
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_flow_label, tvb, offset, tlv_len, ENC_NA);
                break;

            case PROXY_SEGMENT_CONTROL:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_seven_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_proxy_segment_control, tvb, offset, 1, aux_byte);
                offset += 1;
                break;

            case PROXY_PUT_RESP:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_proxy_delivery_code, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_file_stat, tvb, offset, 1, aux_byte);
                offset += 1;
                break;

            case PROXY_FILESTORE_RESP:
                offset = dissect_cfdp_filestore_req_tlv(tvb, cfdp_msg_to_user_tree, offset);
                break;

            case PROXY_PUT_CANCEL:
                break;

            case ORIG_TRANS_ID:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_res2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_entid_length, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_res3, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, aux_byte);
                offset += 1;

                len_ent_id = ((aux_byte & HDR_LEN_ENT_ID) >> 4) + 1;
                dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_ent_id);
                offset += len_ent_id;

                len_tseq_num = (aux_byte & HDR_LEN_TSEQ_NUM) +1;
                dissect_cfdp_tseq_num(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_tseq_num);
                offset += len_tseq_num;

                break;

            case DIRECTORY_LIST_REQ:
                /* Directory Name */
                tlv_len =  tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_directory_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;
                /* Directory File Name */
                tlv_len =  tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_directory_file_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;
                break;

            case DIRECTORY_LIST_RESP:
                /* Listing Response Code */
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_listing_resp_code, tvb, offset, 1, aux_byte);
                offset += 1;
                /* Directory Name */
                tlv_len =  tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_directory_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;
                /* Directory File Name */
                tlv_len =  tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_directory_file_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;
                break;

            case REMOTE_STAT_REP_REQ:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_res2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_entid_length, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_res3, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, aux_byte);
                offset += 1;

                len_ent_id = ((aux_byte & HDR_LEN_ENT_ID) >> 4) + 1;
                dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_ent_id);
                offset += len_ent_id;

                len_tseq_num = (aux_byte & HDR_LEN_TSEQ_NUM) +1;
                dissect_cfdp_tseq_num(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_tseq_num);
                offset += len_tseq_num;

                /* Report File Name */
                tlv_len =  tvb_get_guint8(tvb, offset);
                offset += 1;
                proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_report_file_name, tvb, offset, tlv_len, ENC_ASCII|ENC_NA);
                offset += tlv_len;
                break;

            case REMOTE_STAT_REP_RESP:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_trans_stat, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_five, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_rep_resp_code, tvb, offset, 1, aux_byte);
                offset += 1;

                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_entid_length, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, aux_byte);
                offset += 1;

                len_ent_id = ((aux_byte & HDR_LEN_ENT_ID) >> 4) + 1;
                dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_ent_id);
                offset += len_ent_id;

                len_tseq_num = (aux_byte & HDR_LEN_TSEQ_NUM) +1;
                dissect_cfdp_tseq_num(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_tseq_num);
                offset += len_tseq_num;
                break;

            case REMOTE_SUSPEND_REQ:
            case REMOTE_RESUME_REQ:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_entid_length, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, aux_byte);
                offset += 1;

                len_ent_id = ((aux_byte & HDR_LEN_ENT_ID) >> 4) + 1;
                dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_ent_id);
                offset += len_ent_id;

                len_tseq_num = (aux_byte & HDR_LEN_TSEQ_NUM) +1;
                dissect_cfdp_tseq_num(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_tseq_num);
                offset += len_tseq_num;
                break;

            case REMOTE_SUSPEND_RESP:
            case REMOTE_RESUME_RESP:
                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_suspension_ind, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_trans_stat_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_five, tvb, offset, 1, aux_byte);
                offset += 1;

                aux_byte = tvb_get_guint8(tvb, offset);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one_2, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_entid_length, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_spare_one, tvb, offset, 1, aux_byte);
                proto_tree_add_uint(cfdp_msg_to_user_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, aux_byte);
                offset += 1;

                len_ent_id = ((aux_byte & HDR_LEN_ENT_ID) >> 4) + 1;
                dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_ent_id);
                offset += len_ent_id;

                len_tseq_num = (aux_byte & HDR_LEN_TSEQ_NUM) +1;
                dissect_cfdp_tseq_num(tvb, pinfo, cfdp_msg_to_user_tree, offset, len_tseq_num);
                offset += len_tseq_num;
                break;

            default:
                break;
        }
    }else{
        proto_tree_add_item(cfdp_msg_to_user_tree, hf_cfdp_message_to_user, tvb, offset, tlv_len, ENC_NA);
        offset += tlv_len;
    }

    return offset;
}

/* Dissect the Fault Handler Override TLV */
static guint32 dissect_cfdp_fault_handler_overr_tlv(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint8 aux_byte, tlv_len;
    proto_tree  *cfdp_fault_hdl_overr_tree;

    guint32 offset = ext_offset;

    /* Get tlv len */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;

    /* Create a subtree */
    cfdp_fault_hdl_overr_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                        ett_cfdp_fault_hdl_overr, NULL, "Fault Handler Override TLV");

    proto_tree_add_uint(cfdp_fault_hdl_overr_tree, hf_cfdp_tlv_len, tvb, offset-1, 1, tlv_len);

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(cfdp_fault_hdl_overr_tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(cfdp_fault_hdl_overr_tree, hf_cfdp_handler_code, tvb, offset, 1, aux_byte);
    offset += 1;

    return offset;
}

/* Dissect the Flow Label TLV */
static guint32 dissect_cfdp_flow_label_tlv(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint8 tlv_len;
    proto_tree  *cfdp_flow_label_tree;

    guint32 offset = ext_offset;

    /* Get tlv len */
    tlv_len = tvb_get_guint8(tvb, offset);
    offset += 1;

    /* Create a subtree */
    cfdp_flow_label_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                                        ett_cfdp_flow_label, NULL, "Flow Label TLV");

    /* It is undefined, so no specific encoding */
    proto_tree_add_item(cfdp_flow_label_tree, hf_cfdp_flow_label, tvb, offset, tlv_len, ENC_NA);

    return offset;
}

/* Dissect the End of File PDU */
static guint32 dissect_cfdp_eof_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset, guint ext_packet_len){

    guint8 aux_byte, tlv_type, tlv_len;
    proto_tree  *cfdp_fault_location_tree;

    guint32 offset = ext_offset;
    guint   cfdp_packet_data_length = ext_packet_len;

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_spare_four, tvb, offset, 1, aux_byte);
    offset += 1;

    col_add_fstr(pinfo->cinfo, COL_INFO, "EOF (%s)",  val_to_str_const((aux_byte & 0xF0) >> 4, cfdp_condition_codes, "Reserved Code"));

    proto_tree_add_checksum(tree, tvb, offset, hf_cfdp_file_checksum, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
    offset += 4;

    proto_tree_add_item(tree, hf_cfdp_file_size, tvb, offset, 4, ENC_BIG_ENDIAN);
    offset += 4;

    if(offset < cfdp_packet_data_length){
        tlv_type = tvb_get_guint8(tvb, offset);
        offset += 1;
        if(tlv_type == FAULT_LOCATION){
            tlv_len = tvb_get_guint8(tvb, offset);
            offset += 1;
            cfdp_fault_location_tree = proto_tree_add_subtree(tree, tvb, offset-2, tlv_len+2,
                        ett_cfdp_fault_location, NULL, "Fault location TLV");

            proto_tree_add_item(cfdp_fault_location_tree, hf_cfdp_entity, tvb, offset, tlv_len, ENC_NA);
            offset += tlv_len;
        }
    }

    return offset;
}

/* Dissect the Finished PDU */
static guint32 dissect_cfdp_finished_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset, guint ext_packet_len){

    guint32 offset = ext_offset;
    guint8  aux_byte, tlv_type;


    guint cfdp_packet_data_length = ext_packet_len;

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_condition_code,  tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_end_system_stat, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_delivery_code,   tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_file_stat,       tvb, offset, 1, aux_byte);
    offset += 1;

    col_add_fstr(pinfo->cinfo, COL_INFO, "Finished PDU (%s)",  val_to_str_const((aux_byte & 0xF0) >> 4, cfdp_condition_codes, "Reserved Code"));

    /* Add TLV fields */
    while(offset < cfdp_packet_data_length){
        tlv_type = tvb_get_guint8(tvb, offset);
        offset += 1;
        switch(tlv_type){
            case FILESTORE_RESP:
                offset = dissect_cfdp_filestore_resp_tlv(tvb, tree, offset);
                break;

            case FAULT_LOCATION:
                offset = dissect_cfdp_fault_location_tlv(tvb, tree, offset);
                break;

            default:
                break;
        }
    }

    return offset;
}

/* Dissect the ACK PDU */
static guint32 dissect_cfdp_ack_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset){

    guint8 aux_byte;
    guint32 offset = ext_offset;

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_dir_code_ack, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_dir_subtype_ack, tvb, offset, 1, aux_byte);
    offset += 1;

    col_add_fstr(pinfo->cinfo, COL_INFO, "ACK PDU (%s)",  val_to_str_const((aux_byte & 0xF0) >> 4, cfdp_directive_codes, "Unknown PDU"));

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_condition_code, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_spare_two, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_trans_stat_ack, tvb, offset, 1, aux_byte);
    offset += 1;

    return offset;
}

/* Dissect the Metadata PDU */
static guint32 dissect_cfdp_metadata_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset, guint ext_packet_len){

    guint8 aux_byte, tlv_type;
    guint  cfdp_packet_data_length = ext_packet_len;

    guint32 offset = ext_offset;

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_segment_control, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_spare_seven, tvb, offset, 1, aux_byte);
    offset += 1;
    proto_tree_add_item(tree, hf_cfdp_file_size, tvb, offset, 4, ENC_BIG_ENDIAN);
    offset += 4;
    aux_byte = tvb_get_guint8(tvb, offset);
    if(aux_byte >0){
        proto_tree_add_item(tree, hf_cfdp_src_file_name, tvb, offset+1, aux_byte, ENC_ASCII|ENC_NA);
        offset += aux_byte+1;
        aux_byte = tvb_get_guint8(tvb, offset);
        proto_tree_add_item(tree, hf_cfdp_dst_file_name, tvb, offset+1, aux_byte, ENC_ASCII|ENC_NA);
        offset += aux_byte+1;
    }
    /* Add TLV fields */
    while(offset < cfdp_packet_data_length){
        tlv_type = tvb_get_guint8(tvb, offset);
        offset += 1;
        switch(tlv_type){
            case FILESTORE_REQ:
                offset = dissect_cfdp_filestore_req_tlv(tvb, tree, offset);
                break;

            case MSG_TO_USER:
                offset = dissect_cfdp_msg_to_user_tlv(tvb, pinfo, tree, offset);
                break;

            case FAULT_HDL_OVERR:
                offset = dissect_cfdp_fault_handler_overr_tlv(tvb, tree, offset);
                break;

            case FLOW_LABEL:
                offset = dissect_cfdp_flow_label_tlv(tvb, tree, offset);
                break;

            default:
                break;
        }
    }

    return offset;
}

/* Dissect the NAK PDU */
static guint32 dissect_cfdp_nak_pdu(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset, guint ext_packet_len){

    guint32 offset = ext_offset;
    guint cfdp_packet_data_length = ext_packet_len;

    proto_tree_add_item(tree, hf_cfdp_nak_st_scope, tvb, offset, 4, ENC_BIG_ENDIAN);
    offset += 4;
    proto_tree_add_item(tree, hf_cfdp_nak_sp_scope, tvb, offset, 4, ENC_BIG_ENDIAN);
    offset += 4;
    proto_tree_add_item(tree, hf_cfdp_segment_requests, tvb, offset, cfdp_packet_data_length-9, ENC_NA);
    offset += cfdp_packet_data_length-9;

    return offset;
}

/* Dissect the Prompt PDU */
static guint32 dissect_cfdp_prompt_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ext_offset){

    guint8 aux_byte;
    guint32 offset = ext_offset;

    aux_byte = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(tree, hf_cfdp_response_req, tvb, offset, 1, aux_byte);
    proto_tree_add_uint(tree, hf_cfdp_spare_seven, tvb, offset, 1, aux_byte);
    offset += 1;

    col_add_fstr(pinfo->cinfo, COL_INFO, "Prompt PDU (%s)",  val_to_str_const((aux_byte & 0x80) >> 7, cfdp_response_req, "Unknown"));

    return offset;
}

/* Dissect the Keep Alive PDU */
static guint32 dissect_cfdp_keep_alive_pdu(tvbuff_t *tvb, proto_tree *tree, guint32 ext_offset){

    guint32 offset = ext_offset;

    proto_tree_add_item(tree, hf_cfdp_progress, tvb, offset, 4, ENC_BIG_ENDIAN);
    offset += 4;

    return offset;
}

/* Code to actually dissect the packets */
static int
dissect_cfdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
    int          offset          = 0;
    proto_item  *cfdp_packet;
    proto_item  *cfdp_tree;
    proto_item  *cfdp_header;
    proto_tree  *cfdp_header_tree;
    gint cfdp_packet_length;
    gint cfdp_packet_reported_length;
    gint cfdp_packet_header_length;
    gint cfdp_packet_data_length;
    gint length;
    guint8 first_byte;
    guint8 second_byte;
    gint len_ent_id;
    gint len_tseq_num;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "CFDP");
    col_clear(pinfo->cinfo, COL_INFO);

    cfdp_packet_reported_length = tvb_reported_length_remaining(tvb, 0);
    cfdp_packet_header_length = (tvb_get_guint8(tvb, 3) & HDR_LEN_TSEQ_NUM) + 1 + 2*(((tvb_get_guint8(tvb, 3) & HDR_LEN_ENT_ID) >>4) +1) + CFDP_HEADER_FIXED_FIELDS_LEN;
    cfdp_packet_length = tvb_get_ntohs(tvb, 1) + cfdp_packet_header_length;



    /* Min length is size of header plus 2 octets, whereas max length is reported length.
     * If the length field in the CFDP header is outside of these bounds,
     * use the value it violates.  Otherwise, use the length field value.
     */
    if(cfdp_packet_length > cfdp_packet_reported_length)
        length = cfdp_packet_reported_length;
    else if(cfdp_packet_length < cfdp_packet_header_length + 2)
        length = cfdp_packet_header_length + 2;
    else
        length = cfdp_packet_length;

    /* Build the cfdp tree */
    cfdp_packet = proto_tree_add_item(tree, proto_cfdp, tvb, 0, length, ENC_NA);
    cfdp_tree   = proto_item_add_subtree(cfdp_packet, ett_cfdp);

    cfdp_header_tree = proto_tree_add_subtree(cfdp_tree, tvb, offset, cfdp_packet_header_length,
                                                                ett_cfdp_header, &cfdp_header, "CFDP Header");

    first_byte = tvb_get_guint8(tvb, offset);

    /* CRC code is not included in the packet data length */
    cfdp_packet_data_length = tvb_get_ntohs(tvb, 1)-2*((first_byte & HDR_CRCF) >>1);

    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_version,    tvb, offset, 1, first_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_pdu_type,   tvb, offset, 1, first_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_direction,  tvb, offset, 1, first_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_trans_mode, tvb, offset, 1, first_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_crc_flag,   tvb, offset, 1, first_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_res1,       tvb, offset, 1, first_byte);
    offset += 1;

    proto_tree_add_item(cfdp_header_tree, hf_cfdp_data_length, tvb, offset, 2, ENC_BIG_ENDIAN);
    offset += 2;

    second_byte = tvb_get_guint8(tvb, offset);

    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_res2, tvb, offset, 1, second_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_entid_length, tvb, offset, 1, second_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_res3, tvb, offset, 1, second_byte);
    proto_tree_add_uint(cfdp_header_tree, hf_cfdp_transeqnum_length, tvb, offset, 1, second_byte);
    offset += 1;

    len_ent_id = ((second_byte & HDR_LEN_ENT_ID) >> 4) + 1;
    dissect_cfdp_src_entity_id(tvb, pinfo, cfdp_header_tree, offset, len_ent_id);
    offset += len_ent_id;

    len_tseq_num = (second_byte & HDR_LEN_TSEQ_NUM) +1;
    dissect_cfdp_tseq_num(tvb, pinfo, cfdp_header_tree, offset, len_tseq_num);
    offset += len_tseq_num;

    dissect_cfdp_dst_entity_id(tvb, pinfo, cfdp_header_tree, offset, len_ent_id);
    offset += len_ent_id;

    proto_item_set_end(cfdp_header, tvb, offset);

    /* Build the File Directive or the File Data tree */
    if(!(first_byte & HDR_TYPE_CFDP))
    {
        proto_item *cfdp_file_directive_header;
        proto_tree *cfdp_file_directive_header_tree;
        guint8      directive_code;

        cfdp_file_directive_header_tree = proto_tree_add_subtree(cfdp_tree, tvb, offset, cfdp_packet_data_length,
                                                        ett_cfdp_file_directive_header, &cfdp_file_directive_header, "CFDP File Directive");

        directive_code = tvb_get_guint8(tvb, offset);
        proto_tree_add_uint(cfdp_file_directive_header_tree, hf_cfdp_file_directive_type, tvb, offset, 1, directive_code);
        offset += 1;

        col_add_fstr(pinfo->cinfo, COL_INFO, "%s PDU",  val_to_str(directive_code, cfdp_directive_codes, "Reserved (%d)"));

        switch(directive_code)
        {
            case EOF_PDU:
                offset = dissect_cfdp_eof_pdu(tvb, pinfo, cfdp_file_directive_header_tree, offset, cfdp_packet_data_length);
                break;

            case FINISHED_PDU:
                offset = dissect_cfdp_finished_pdu(tvb, pinfo, cfdp_file_directive_header_tree, offset, cfdp_packet_data_length);
                break;

            case ACK_PDU:
                offset = dissect_cfdp_ack_pdu(tvb, pinfo, cfdp_file_directive_header_tree, offset);
                break;

            case METADATA_PDU:
                offset = dissect_cfdp_metadata_pdu(tvb, pinfo, cfdp_file_directive_header_tree, offset, cfdp_packet_data_length);
                break;

            case NAK_PDU:
                offset = dissect_cfdp_nak_pdu(tvb, cfdp_file_directive_header_tree, offset, cfdp_packet_data_length);
                break;

            case PROMPT_PDU:
                offset = dissect_cfdp_prompt_pdu(tvb, pinfo, cfdp_file_directive_header_tree, offset);
                break;

            case KEEP_ALIVE_PDU:
                offset = dissect_cfdp_keep_alive_pdu(tvb, cfdp_file_directive_header_tree, offset);
                break;

            default:
                break;
        }

        proto_item_set_end(cfdp_file_directive_header, tvb, offset);

    }else{
        proto_tree  *cfdp_file_data_header_tree;

        col_add_fstr(pinfo->cinfo, COL_INFO, "File Data PDU");

        cfdp_file_data_header_tree = proto_tree_add_subtree(cfdp_tree, tvb, offset, cfdp_packet_data_length,
                                                            ett_cfdp_file_data_header, NULL, "CFDP File Data");

        proto_tree_add_item(cfdp_file_data_header_tree, hf_cfdp_file_data_offset, tvb, offset, 4, ENC_BIG_ENDIAN);

        offset += 4;

        proto_tree_add_item(cfdp_file_data_header_tree, hf_cfdp_user_data, tvb, offset, cfdp_packet_data_length-4, ENC_NA);
        offset += cfdp_packet_data_length-4;

    }
    if(first_byte & HDR_CRCF){
        proto_item  *cfdp_crc;
        proto_tree  *cfdp_crc_tree;

        cfdp_crc_tree = proto_tree_add_subtree(cfdp_tree, tvb, offset, 2, ett_cfdp_crc, &cfdp_crc, "CRC");

        proto_tree_add_item(cfdp_crc_tree, hf_cfdp_crc, tvb, offset, 2, ENC_BIG_ENDIAN);
        offset += 2;

        proto_item_set_end(cfdp_crc, tvb, offset);
    }
    /* Give the data dissector any bytes past the CFDP packet length */
    call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
    return tvb_captured_length(tvb);
}

void
proto_register_cfdp(void)
{
    static hf_register_info hf[] = {

        { &hf_cfdp_version,
        { "Version", "cfdp.version",
            FT_UINT8, BASE_DEC, NULL, HDR_VERSION_CFDP,
            NULL, HFILL }
        },
        { &hf_cfdp_pdu_type,
            { "PDU Type", "cfdp.pdu_type",
            FT_UINT8, BASE_DEC, VALS(cfdp_pdu_type), HDR_TYPE_CFDP,
            NULL, HFILL }
        },
        { &hf_cfdp_direction,
            { "Direction", "cfdp.direction",
            FT_UINT8, BASE_DEC, VALS(cfdp_direction), HDR_DIR,
            NULL, HFILL }
        },
        { &hf_cfdp_trans_mode,
            { "Trans. Mode", "cfdp.trans_mode",
            FT_UINT8, BASE_DEC, VALS(cfdp_trans_mode), HDR_TMODE,
            NULL, HFILL }
        },
        { &hf_cfdp_crc_flag,
            { "CRC Flag", "cfdp.crc_flag",
            FT_UINT8, BASE_DEC, VALS(cfdp_crc_flag), HDR_CRCF,
            NULL, HFILL }
        },
        { &hf_cfdp_res1,
            { "Bit reserved 1", "cfdp.res1",
            FT_UINT8, BASE_DEC, NULL, HDR_RES1,
            NULL, HFILL }
        },
        { &hf_cfdp_data_length,
            { "PDU Data length", "cfdp.data_length",
            FT_UINT16, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_res2,
            { "Bit reserved 2", "cfdp.res2",
            FT_UINT8, BASE_DEC, NULL, 0x80,
            NULL, HFILL }
        },
        { &hf_cfdp_entid_length,
            { "Length of entity IDs", "cfdp.entid_length",
            FT_UINT8, BASE_DEC, NULL, 0x70,
            NULL, HFILL }
        },
        { &hf_cfdp_res3,
            { "Bit reserved 3", "cfdp.res3",
            FT_UINT8, BASE_DEC, NULL, 0x08,
            NULL, HFILL }
        },
        { &hf_cfdp_transeqnum_length,
            { "Length of Transaction sequence number", "cfdp.transeqnum_length",
            FT_UINT8, BASE_DEC, NULL, 0x07,
            NULL, HFILL }
        },
        { &hf_cfdp_srcid,
            { "Source entity ID", "cfdp.srcid",
            FT_UINT64, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_transeqnum,
            { "Transaction sequence number", "cfdp.transeqnum",
            FT_UINT64, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_dstid,
            { "Destination entity ID", "cfdp.dstid",
            FT_UINT64, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_file_directive_type,
            { "File Directive type", "cfdp.fdtype",
            FT_UINT8, BASE_DEC, VALS(cfdp_file_directive_type), 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_file_data_offset,
            { "Offset", "cfdp.offset",
            FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_progress,
            { "Progress", "cfdp.progress",
            FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_dir_code_ack,
            { "PDU acknowledged", "cfdp.dir_code_ack",
            FT_UINT8, BASE_DEC, VALS(cfdp_file_directive_type), 0xf0,
            NULL, HFILL }
        },
        { &hf_cfdp_dir_subtype_ack,
            { "Directive subtype code", "cfdp.dir_subtype_ack",
            FT_UINT8, BASE_DEC, NULL, 0x0f,
            NULL, HFILL }
        },
        { &hf_cfdp_condition_code,
            { "Condition Code", "cfdp.condition_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_condition_codes), 0xf0,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_one,
            { "Spare", "cfdp.spare_one",
            FT_UINT8, BASE_DEC, NULL, 0x08,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_one_2,
            { "Spare", "cfdp.spare_one_2",
            FT_UINT8, BASE_DEC, NULL, 0x80,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_two,
            { "Spare", "cfdp.spare_two",
            FT_UINT8, BASE_DEC, NULL, 0x0c,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_four,
            { "Spare", "cfdp.spare_four",
            FT_UINT8, BASE_DEC, NULL, 0x0f,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_five,
            { "Spare", "cfdp.spare_five",
            FT_UINT8, BASE_DEC, NULL, 0x3E,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_seven,
            { "Spare", "cfdp.spare_seven",
            FT_UINT8, BASE_DEC, NULL, 0x7f,
            NULL, HFILL }
        },
        { &hf_cfdp_spare_seven_2,
            { "Spare", "cfdp.spare_seven_2",
            FT_UINT8, BASE_DEC, NULL, 0xfe,
            NULL, HFILL }
        },
        { &hf_cfdp_trans_stat_ack,
            { "Transaction status", "cfdp.trans_stat_ack",
            FT_UINT8, BASE_DEC, VALS(cfdp_trans_stat_ack), 0x03,
            NULL, HFILL }
        },
        { &hf_cfdp_trans_stat,
            { "Transaction status", "cfdp.trans_stat",
            FT_UINT8, BASE_DEC, VALS(cfdp_trans_stat_ack), 0xC0,
            NULL, HFILL }
        },
        { &hf_cfdp_trans_stat_2,
            { "Transaction status", "cfdp.trans_stat_2",
            FT_UINT8, BASE_DEC, VALS(cfdp_trans_stat_ack), 0x60,
            NULL, HFILL }
        },
        { &hf_cfdp_file_checksum,
            { "Checksum", "cfdp.checksum",
            FT_UINT32, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_file_size,
            { "File size", "cfdp.file_size",
            FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_end_system_stat,
            { "End system status", "cfdp.end_system_stat",
            FT_UINT8, BASE_DEC, VALS(cfdp_end_system_stat), 0x08,
            NULL, HFILL }
        },
        { &hf_cfdp_delivery_code,
            { "Delivery code", "cfdp.delivery_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_delivery_code), 0x04,
            NULL, HFILL }
        },
        { &hf_cfdp_file_stat,
            { "File status", "cfdp.file_status",
            FT_UINT8, BASE_DEC, VALS(cfdp_file_stat), 0x03,
            NULL, HFILL }
        },
        { &hf_cfdp_segment_control,
            { "Segmentation control", "cfdp.segment_control",
            FT_UINT8, BASE_DEC, VALS(cfdp_segment_control), 0x80,
            NULL, HFILL }
        },
        { &hf_cfdp_tlv_len,
            { "Length", "cfdp.tlv_length",
            FT_UINT8, BASE_DEC, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_src_file_name,
            {"Source file name", "cfdp.src_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_dst_file_name,
            {"Destination file name", "cfdp.dst_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_first_file_name,
            {"First file name", "cfdp.first_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_second_file_name,
            {"Second file name", "cfdp.second_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_nak_st_scope,
            {"Start of scope", "cfdp.nak_st_scope", FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_nak_sp_scope,
            {"End of scope", "cfdp.nak_sp_scope", FT_UINT32, BASE_DEC, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_crc,
            {"CRC", "cfdp.crc", FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_action_code,
            {"Action code", "cfdp.action_code", FT_UINT8, BASE_DEC, VALS(cfdp_action_code), 0xF0,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_1,
            {"Status code", "cfdp.status_code_1", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_1), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_2,
            {"Status code", "cfdp.status_code_2", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_2), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_3,
            {"Status code", "cfdp.status_code_3", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_3), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_4,
            {"Status code", "cfdp.status_code_4", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_4), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_5,
            {"Status code", "cfdp.status_code_5", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_5), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_6,
            {"Status code", "cfdp.status_code_6", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_6), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_7,
            {"Status code", "cfdp.status_code_7", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_7), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_status_code_8,
            {"Status code", "cfdp.status_code_8", FT_UINT8, BASE_DEC, VALS(cfdp_status_code_8), 0x0F,
            NULL, HFILL}
        },
        { &hf_cfdp_handler_code,
            { "Handler Code", "cfdp.handler_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_handler_codes), 0x0F,
            NULL, HFILL }
        },
        { &hf_cfdp_trans_mode_msg,
            { "Trans. Mode", "cfdp.trans_mode_msg",
            FT_UINT8, BASE_DEC, VALS(cfdp_trans_mode), 0x01,
            NULL, HFILL }
        },
        { &hf_cfdp_proxy_msg_type,
            { "Proxy Message Type", "cfdp.proxy_msg_type",
            FT_UINT8, BASE_DEC | BASE_EXT_STRING, &cfdp_proxy_msg_type_ext, 0x0,
            NULL, HFILL }
        },
        { &hf_cfdp_proxy_segment_control,
            { "Segmentation control", "cfdp.proxy_segment_control",
            FT_UINT8, BASE_DEC, VALS(cfdp_segment_control), 0x01,
            NULL, HFILL }
        },
        { &hf_cfdp_proxy_delivery_code,
            { "Delivery code", "cfdp.proxy_delivery_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_delivery_code), 0x04,
            NULL, HFILL }
        },
        { &hf_cfdp_response_req,
            { "Response required", "cfdp.response_req",
            FT_UINT8, BASE_DEC, VALS(cfdp_response_req), 0x80,
            NULL, HFILL }
        },
        { &hf_cfdp_directory_name,
            {"Directory Name", "cfdp.directory_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_directory_file_name,
            {"Directory File Name", "cfdp.directory_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_listing_resp_code,
            {"Listing Response Code", "cfdp.listing_resp_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_listing_resp_code), 0x80,
            NULL, HFILL}
        },
        { &hf_cfdp_report_file_name,
            {"Report File Name", "cfdp.report_file_name", FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_cfdp_rep_resp_code,
            {"Report Response Code", "cfdp.rep_resp_code",
            FT_UINT8, BASE_DEC, VALS(cfdp_rep_resp_code), 0x01,
            NULL, HFILL}
        },
        { &hf_cfdp_suspension_ind,
            {"Suspension indicator", "cfdp.suspension_ind",
            FT_UINT8, BASE_DEC, VALS(cfdp_suspension_ind), 0x80,
            NULL, HFILL}
        },

        /* Generated from convert_proto_tree_add_text.pl */
        { &hf_cfdp_filestore_message, { "Filestore Message", "cfdp.filestore_message", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_cfdp_entity, { "Entity", "cfdp.entity", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_cfdp_message_to_user, { "Message to User", "cfdp.message_to_user", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_cfdp_flow_label, { "Flow label", "cfdp.flow_label", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_cfdp_segment_requests, { "Segment requests", "cfdp.segment_requests", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_cfdp_user_data, { "User Data", "cfdp.user_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},

    };

    /* Setup protocol subtree array */
    static gint *ett[] = {
        &ett_cfdp,
        &ett_cfdp_header,
        &ett_cfdp_file_directive_header,
        &ett_cfdp_file_data_header,
        &ett_cfdp_fault_location,
        &ett_cfdp_crc,
        &ett_cfdp_filestore_req,
        &ett_cfdp_filestore_resp,
        &ett_cfdp_msg_to_user,
        &ett_cfdp_fault_hdl_overr,
        &ett_cfdp_flow_label
    };

    static ei_register_info ei[] = {
        { &ei_cfdp_bad_length, { "cfdp.bad_length", PI_MALFORMED, PI_ERROR, "Bad length field", EXPFILL }},
    };

    expert_module_t* expert_cfdp;

    /* Register the protocol name and description */
    proto_cfdp = proto_register_protocol("CFDP", "CFDP", "cfdp");

    /* Required function calls to register the header fields and subtrees used */
    proto_register_field_array(proto_cfdp, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    expert_cfdp = expert_register_protocol(proto_cfdp);
    expert_register_field_array(expert_cfdp, ei, array_length(ei));

    cfdp_handle = register_dissector("cfdp", dissect_cfdp, proto_cfdp);
}

void
proto_reg_handoff_cfdp(void)
{
    dissector_add_uint("ccsds.apid", CFDP_APID, cfdp_handle);
    dissector_add_for_decode_as_with_preference("udp.port", cfdp_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:
 */