/* packet-fc.c
 * Routines for Fibre Channel Decoding (FC Header, Link Ctl & Basic Link Svc) 
 * Copyright 2001, Dinesh G Dutt <ddutt@cisco.com>
 *   Copyright 2003  Ronnie Sahlberg, exchange first/last matching and 
 *                                    tap listener and misc updates
 *
 * $Id: packet-fc.c 15076 2005-07-26 00:54:16Z sahlberg $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 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>

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

#include <glib.h>

#ifdef NEED_SNPRINTF_H
# include "snprintf.h"
#endif

#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/reassemble.h>
#include <epan/conversation.h>
#include "etypes.h"
#include "packet-fc.h"
#include "packet-fclctl.h"
#include "packet-fcbls.h"
#include <epan/tap.h>

#define FC_HEADER_SIZE         24
#define FC_RCTL_EISL           0x50
#define MDSHDR_TRAILER_SIZE    6 

/* Size of various fields in FC header in bytes */
#define FC_RCTL_SIZE           1
#define FC_DID_SIZE            3
#define FC_CSCTL_SIZE          1
#define FC_SID_SIZE            3
#define FC_TYPE_SIZE           1
#define FC_FCTL_SIZE           3
#define FC_SEQID_SIZE          1
#define FC_DFCTL_SIZE          1
#define FC_SEQCNT_SIZE         2
#define FC_OXID_SIZE           2
#define FC_RXID_SIZE           2
#define FC_PARAM_SIZE          4

/* Initialize the protocol and registered fields */
static int proto_fc = -1;
static int hf_fc_time = -1;
static int hf_fc_exchange_first_frame = -1;
static int hf_fc_exchange_last_frame = -1;
static int hf_fc_rctl = -1;
static int hf_fc_did = -1;
static int hf_fc_csctl = -1;
static int hf_fc_sid = -1;
static int hf_fc_id = -1;
static int hf_fc_type = -1;
static int hf_fc_fctl = -1;
static int hf_fc_fctl_exchange_responder = -1;
static int hf_fc_fctl_seq_recipient = -1;
static int hf_fc_fctl_exchange_first = -1;
static int hf_fc_fctl_exchange_last = -1;
static int hf_fc_fctl_seq_last = -1;
static int hf_fc_fctl_priority = -1;
static int hf_fc_fctl_transfer_seq_initiative = -1;
static int hf_fc_fctl_rexmitted_seq = -1;
static int hf_fc_fctl_rel_offset = -1;
static int hf_fc_fctl_abts_ack = -1;
static int hf_fc_fctl_abts_not_ack = -1;
static int hf_fc_fctl_last_data_frame = -1;
static int hf_fc_fctl_ack_0_1 = -1;
static int hf_fc_seqid = -1;
static int hf_fc_dfctl = -1;
static int hf_fc_seqcnt = -1;
static int hf_fc_oxid = -1;
static int hf_fc_rxid = -1;
static int hf_fc_param = -1;
static int hf_fc_ftype = -1;    /* Derived field, non-existent in FC hdr */
static int hf_fc_reassembled = -1;
static int hf_fc_eisl = -1;

/* Network_Header fields */
static int hf_fc_nh_da = -1;
static int hf_fc_nh_sa = -1;

/* For Basic Link Svc */
static int hf_fc_bls_seqid_vld = -1;
static int hf_fc_bls_lastvld_seqid = -1;
static int hf_fc_bls_oxid = -1;
static int hf_fc_bls_rxid = -1;
static int hf_fc_bls_lowseqcnt = -1;
static int hf_fc_bls_hiseqcnt = -1;
static int hf_fc_bls_rjtcode = -1;
static int hf_fc_bls_rjtdetail = -1;
static int hf_fc_bls_vendor = -1;


/* Initialize the subtree pointers */
static gint ett_fc = -1;
static gint ett_fctl = -1;
static gint ett_fcbls = -1;

static dissector_table_t fcftype_dissector_table;
static dissector_handle_t data_handle;

static int fc_tap = -1;

/* Reassembly stuff */
static gboolean fc_reassemble = TRUE;
static guint32  fc_max_frame_size = 1024;
static GHashTable *fc_fragment_table = NULL;

typedef struct _fcseq_conv_key {
    guint32 conv_idx;
} fcseq_conv_key_t;

typedef struct _fcseq_conv_data {
    guint32 seq_cnt;
} fcseq_conv_data_t;

GHashTable *fcseq_req_hash = NULL;
GMemChunk *fcseq_req_keys = NULL;
GMemChunk *fcseq_req_vals = NULL;
guint32 fcseq_init_count = 25;

static GHashTable *fc_exchange_unmatched = NULL;
static GHashTable *fc_exchange_matched = NULL;
static GMemChunk *fc_exchange_vals = NULL;
static guint32 fc_exchange_init_count = 200;

/*
 * Hash Functions
 */
static gint
fcseq_equal(gconstpointer v, gconstpointer w)
{
  const fcseq_conv_key_t *v1 = v;
  const fcseq_conv_key_t *v2 = w;

  return (v1->conv_idx == v2->conv_idx);
}

static guint
fcseq_hash (gconstpointer v)
{
    const fcseq_conv_key_t *key = v;
    guint val;
    
    val = key->conv_idx;
    
    return val;
}

static guint
fc_exchange_hash_unmatched(gconstpointer v)
{
    const fc_exchange_data *fced=(const fc_exchange_data *)v;

    return fced->oxid;
}
static gint
fc_exchange_equal_unmatched(gconstpointer v1, gconstpointer v2)
{
    const fc_exchange_data *fced1=(const fc_exchange_data *)v1;
    const fc_exchange_data *fced2=(const fc_exchange_data *)v2;

    /* oxid must match */
    if(fced1->oxid!=fced2->oxid){
        return 0;
    }
    /* compare s_id, d_id and treat the fc address
       s_id==00.00.00 as a wildcard matching anything */
    if( ((fced1->s_id.data[0]!=0)||(fced1->s_id.data[1]!=0)||(fced1->s_id.data[2]!=0)) && CMP_ADDRESS(&fced1->s_id, &fced2->s_id) ){
        return 0;
    }
    if(CMP_ADDRESS(&fced1->d_id, &fced2->d_id)){
        return 0;
    }

    return 1;
}

static guint
fc_exchange_hash_matched(gconstpointer v)
{
    const fc_exchange_data *fced=(const fc_exchange_data *)v;

    return fced->oxid;
}
static gint
fc_exchange_equal_matched(gconstpointer v1, gconstpointer v2)
{
    const fc_exchange_data *fced1=(const fc_exchange_data *)v1;
    const fc_exchange_data *fced2=(const fc_exchange_data *)v2;
    guint32 fef1, fef2, lef1, lef2;

    /* oxid must match */
    if(fced1->oxid!=fced2->oxid){
        return 0;
    }
    fef1=fced1->first_exchange_frame;
    fef2=fced2->first_exchange_frame;
    lef1=fced1->last_exchange_frame;
    lef2=fced2->last_exchange_frame;
    if(!fef1)fef1=fef2;
    if(!fef2)fef2=fef1;
    if(!lef1)lef1=lef2;
    if(!lef2)lef2=lef1;

    if(fef1!=fef2){
        return 0;
    }
    if(lef1!=lef2){
        return 0;
    }

    return 1;
}

static void
fc_exchange_init_protocol(void)
{
    if(fc_exchange_vals){
        g_mem_chunk_destroy(fc_exchange_vals);
        fc_exchange_vals=NULL;
    }
    if(fc_exchange_unmatched){
        g_hash_table_destroy(fc_exchange_unmatched);
        fc_exchange_unmatched=NULL;
    }
    if(fc_exchange_matched){
        g_hash_table_destroy(fc_exchange_matched);
        fc_exchange_matched=NULL;
    }

    fc_exchange_unmatched=g_hash_table_new(fc_exchange_hash_unmatched, fc_exchange_equal_unmatched);
    fc_exchange_matched=g_hash_table_new(fc_exchange_hash_matched, fc_exchange_equal_matched);
    fc_exchange_vals=g_mem_chunk_new("fc_exchange_vals", sizeof(fc_exchange_data), fc_exchange_init_count*sizeof(fc_exchange_data), G_ALLOC_AND_FREE);

    fragment_table_init(&fc_fragment_table);

    if (fcseq_req_keys)
        g_mem_chunk_destroy (fcseq_req_keys);
    if (fcseq_req_vals)
        g_mem_chunk_destroy (fcseq_req_vals);
    if (fcseq_req_hash)
        g_hash_table_destroy(fcseq_req_hash);
    
    fcseq_req_hash = g_hash_table_new(fcseq_hash, fcseq_equal);
    fcseq_req_keys = g_mem_chunk_new ("fcseq_req_keys",
                                      sizeof(fcseq_conv_key_t),
                                      fcseq_init_count *
                                      sizeof(fcseq_conv_key_t),
                                      G_ALLOC_AND_FREE);
    fcseq_req_vals = g_mem_chunk_new ("fcseq_req_vals",
                                      sizeof(fcseq_conv_data_t),
                                      fcseq_init_count *
                                      sizeof(fcseq_conv_data_t),
                                      G_ALLOC_AND_FREE);
}


const value_string fc_fc4_val[] = {
    {FC_TYPE_ELS,        "Ext Link Svc"},
    {FC_TYPE_LLCSNAP,    "LLC_SNAP"},
    {FC_TYPE_IP,         "IP/FC"},
    {FC_TYPE_SCSI,       "FCP"},
    {FC_TYPE_FCCT,       "FC_CT"},
    {FC_TYPE_SWILS,      "SW_ILS"},
    {FC_TYPE_AL,         "AL"},
    {FC_TYPE_SNMP,       "SNMP"},
    {FC_TYPE_SB_FROM_CU, "SB-3(CU->Channel)"},
    {FC_TYPE_SB_TO_CU,   "SB-3(Channel->CU)"},
    {0, NULL},
};

static const value_string fc_ftype_vals [] = {
    {FC_FTYPE_UNDEF ,    "Unknown frame"},
    {FC_FTYPE_SWILS,     "SW_ILS"},
    {FC_FTYPE_IP ,       "IP/FC"},
    {FC_FTYPE_SCSI ,     "FCP"},
    {FC_FTYPE_BLS ,      "Basic Link Svc"},
    {FC_FTYPE_ELS ,      "ELS"},
    {FC_FTYPE_FCCT ,     "FC_CT"},
    {FC_FTYPE_LINKDATA,  "Link Data"},
    {FC_FTYPE_VDO,       "Video Data"},
    {FC_FTYPE_LINKCTL,   "Link Ctl"},
    {FC_FTYPE_SBCCS,     "SBCCS"},
    {0, NULL},
};

static const value_string fc_wka_vals[] = {
    {FC_WKA_MULTICAST,    "Multicast Server"},
    {FC_WKA_CLKSYNC,      "Clock Sync Server"},
    {FC_WKA_KEYDIST,      "Key Distribution Server"},
    {FC_WKA_ALIAS,        "Alias Server"},
    {FC_WKA_QOSF,         "QoS Facilitator"},
    {FC_WKA_MGMT,         "Management Server"},
    {FC_WKA_TIME,         "Time Server"},
    {FC_WKA_DNS,          "Directory Server"},
    {FC_WKA_FABRIC_CTRLR, "Fabric Ctlr"},
    {FC_WKA_FPORT,        "F_Port Server"},
    {FC_WKA_BCAST,        "Broadcast ID"},
    {0, NULL},
};

static const value_string fc_routing_val[] = {
    {FC_RCTL_DEV_DATA,  "Device_Data"},
    {FC_RCTL_ELS,       "Extended Link Services"},
    {FC_RCTL_LINK_DATA, "FC-4 Link_Data"},
    {FC_RCTL_VIDEO,     "Video_Data"},
    {FC_RCTL_BLS,       "Basic Link Services"},
    {FC_RCTL_LINK_CTL,  "Link_Control Frame"},
    {0, NULL},
};

static const value_string fc_iu_val[] = {
    {FC_IU_UNCATEGORIZED   , "Uncategorized Data"},
    {FC_IU_SOLICITED_DATA  , "Solicited Data"},
    {FC_IU_UNSOLICITED_CTL , "Unsolicited Control"},
    {FC_IU_SOLICITED_CTL   , "Solicited Control"},
    {FC_IU_UNSOLICITED_DATA, "Solicited Data"},
    {FC_IU_DATA_DESCRIPTOR , "Data Descriptor"},
    {FC_IU_UNSOLICITED_CMD , "Unsolicited Command"},
    {FC_IU_CMD_STATUS      , "Command Status"},
    {0, NULL},
};


static void fc_defragment_init(void)
{
  fragment_table_init (&fc_fragment_table);
}


static gchar *
fctl_to_str (const guint8 *fctl, gchar *str, gboolean is_ack)
{
    int stroff = 0;
    guint8 tmp = 0;

    if (str == NULL)
        return (str);
    
    if (fctl[2] & 0x80) {
        strcpy (str, "Exchange Responder, ");
        stroff += 20;
    }
    else {
        strcpy (str, "Exchange Originator, ");
        stroff += 21;
    }

    if (fctl[2] & 0x40) {
        strcpy (&str[stroff], "Seq Recipient, ");
        stroff += 15;
    }
    else {
        strcpy (&str[stroff], "Seq Initiator, ");
        stroff += 15;
    }

    if (fctl[2] & 0x20) {
        strcpy (&str[stroff], "Exchg First, ");
        stroff += 13;
    }

    if (fctl[2] & 0x10) {
        strcpy (&str[stroff], "Exchg Last, ");
        stroff += 12;
    }

    if (fctl[2] & 0x8) {
        strcpy (&str[stroff], "Seq Last, ");
        stroff += 10;
    }

    if (fctl[2] & 0x2) {
        strcpy (&str[stroff], "Priority, ");
        stroff += 10;
    }
    else {
        strcpy (&str[stroff], "CS_CTL, ");
        stroff += 8;
    }

    if (fctl[2] & 0x1) {
        strcpy (&str[stroff], "Transfer Seq Initiative, ");
        stroff += 25;
    }

    if (fctl[1] & 0x30) {
        strcpy (&str[stroff], "ACK_0 Reqd, ");
        stroff += 12;
    }
    else if (fctl[1] & 0x10) {
        strcpy (&str[stroff], "ACK_1 Reqd, ");
        stroff += 12;
    }

    if (fctl[1] & 0x2) {
        strcpy (&str[stroff], "Rexmitted Seq, ");
        stroff += 15;
    }

    tmp = fctl[0] & 0xC0;
    switch (tmp) {
    case 0:
        strcpy (&str[stroff], "Last Data Frame - No Info, ");
        stroff += 27;
        break;
    case 1:
        strcpy (&str[stroff], "Last Data Frame - Seq Imm, ");
        stroff += 27;
        break;
    case 2:
        strcpy (&str[stroff], "Last Data Frame - Seq Soon, ");
        stroff += 28;
        break;
    case 3:
        strcpy (&str[stroff], "Last Data Frame - Seq Delyd, ");
        stroff += 29;
        break;
    }

    tmp = fctl[0] & 0x30;
    switch (tmp) {
    case 0:
        if (is_ack) {
            strcpy (&str[stroff], "ABTS - Cont, ");
            stroff += 13;
        }
        else {
            strcpy (&str[stroff], "ABTS - Abort/MS, ");
            stroff += 17;
        }
        break;
    case 0x10:
        if (is_ack) {
            strcpy (&str[stroff], "ABTS - AbortABTS - Abort, ");
            stroff += 14;
        }
        else {
            strcpy (&str[stroff], "ABTS - Abort/SS, ");
            stroff += 17;
        }
        break;
    case 0x20:
        if (is_ack) {
            strcpy (&str[stroff], "ABTS - Stop, ");
            stroff += 13;
        }
        else {
            strcpy (&str[stroff], "ABTS - Process/IB, ");
            stroff += 19;
        }
        break;
    case 0x30:
        if (is_ack) {
            strcpy (&str[stroff], "ABTS - Imm Seq Retx, ");
            stroff += 21;
        }
        else {
            strcpy (&str[stroff], "ABTS - Discard/MS/Imm Retx, ");
            stroff += 28;
        }
        break;
    }

    if (fctl[0] & 0x8) {
        strcpy (&str[stroff], "Rel Offset = 1");
        stroff += 14;
    }

    return (str);
}

/* BA_ACC & BA_RJT are decoded in this file itself instead of a traditional
 * dedicated file and dissector format because the dissector would require some
 * fields of the FC_HDR such as param in some cases, type in some others, the
 * lower 4 bits of r_ctl in some other cases etc. So, we decode BLS & Link Ctl
 * in this file itself.
 */
static void
dissect_fc_ba_acc (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    /* Set up structures needed to add the protocol subtree and manage it */
    proto_item *ti;
    proto_tree *acc_tree;
    int offset = 0;

    /* Make entries in Protocol column and Info column on summary display */
    if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "BLS");

    if (check_col(pinfo->cinfo, COL_INFO)) 
        col_set_str(pinfo->cinfo, COL_INFO, "BA_ACC");

    if (tree) {
        ti = proto_tree_add_text (tree, tvb, 0, tvb_length (tvb), "Basic Link Svc");
        acc_tree = proto_item_add_subtree (ti, ett_fcbls);

        proto_tree_add_item (acc_tree, hf_fc_bls_seqid_vld, tvb, offset++, 1, FALSE);
        proto_tree_add_item (acc_tree, hf_fc_bls_lastvld_seqid, tvb, offset++, 1, FALSE);
        offset += 2; /* Skip reserved field */
        proto_tree_add_item (acc_tree, hf_fc_bls_oxid, tvb, offset, 2, FALSE);
        offset += 2;
        proto_tree_add_item (acc_tree, hf_fc_bls_rxid, tvb, offset, 2, FALSE);
        offset += 2;
        proto_tree_add_item (acc_tree, hf_fc_bls_lowseqcnt, tvb, offset, 2, FALSE);
        offset += 2;
        proto_tree_add_item (acc_tree, hf_fc_bls_hiseqcnt, tvb, offset, 2, FALSE);
    }
}

static void
dissect_fc_ba_rjt (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    /* Set up structures needed to add the protocol subtree and manage it */
    proto_item *ti;
    proto_tree *rjt_tree;
    int offset = 0;

    /* Make entries in Protocol column and Info column on summary display */
    if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "BLS");

    if (check_col(pinfo->cinfo, COL_INFO)) 
        col_set_str(pinfo->cinfo, COL_INFO, "BA_RJT");

    if (tree) {
        ti = proto_tree_add_text (tree, tvb, 0, tvb_length (tvb), "Basic Link Svc");
        rjt_tree = proto_item_add_subtree (ti, ett_fcbls);

        proto_tree_add_item (rjt_tree, hf_fc_bls_rjtcode, tvb, offset+1, 1, FALSE);
        proto_tree_add_item (rjt_tree, hf_fc_bls_rjtdetail, tvb, offset+2, 1, FALSE);
        proto_tree_add_item (rjt_tree, hf_fc_bls_vendor, tvb, offset+3, 1, FALSE);
    }
}

static guint8
fc_get_ftype (guint8 r_ctl, guint8 type)
{
    /* A simple attempt to determine the upper level protocol based on the
     * r_ctl & type fields.
     */
    switch (r_ctl & 0xF0) {
    case FC_RCTL_DEV_DATA:
        switch (type) {
        case FC_TYPE_SWILS:
            if ((r_ctl == 0x2) || (r_ctl == 0x3))
                return FC_FTYPE_SWILS;
            else
                return FC_FTYPE_UNDEF;
        case FC_TYPE_IP:
            return FC_FTYPE_IP;
        case FC_TYPE_SCSI:
            return FC_FTYPE_SCSI;
        case FC_TYPE_FCCT:
            return FC_FTYPE_FCCT;
        case FC_TYPE_SB_FROM_CU:
        case FC_TYPE_SB_TO_CU:
            return FC_FTYPE_SBCCS;
        default:
            return FC_FTYPE_UNDEF;
        }
        break;
    case FC_RCTL_ELS:
        if (((r_ctl & 0x0F) == 0x2) || ((r_ctl & 0x0F) == 0x3))
            return FC_FTYPE_ELS;
        else
            return FC_FTYPE_UNDEF;
        break;
    case FC_RCTL_LINK_DATA:
        return FC_FTYPE_LINKDATA;
        break;
    case FC_RCTL_VIDEO:
        return FC_FTYPE_VDO;
        break;
    case FC_RCTL_BLS:
        if (type == 0)
            return FC_FTYPE_BLS;
        else
            return FC_FTYPE_UNDEF;
        break;
    case FC_RCTL_LINK_CTL:
        return FC_FTYPE_LINKCTL;
        break;
    default:
        return FC_FTYPE_UNDEF;
        break;
    }
}

static const value_string abts_ack_vals[] = {
	{0x000000,	"ABTS - Cont"},
	{0x000010,	"ABTS - Abort"},
	{0x000020,	"ABTS - Stop"},
	{0x000030,	"ABTS - Imm Seq Retx"},
	{0,NULL}
};
static const value_string abts_not_ack_vals[] = {
	{0x000000,	"ABTS - Abort/MS"},
	{0x000010,	"ABTS - Abort/SS"},
	{0x000020,	"ABTS - Process/IB"},
	{0x000030,	"ABTS - Discard/MS/Imm Retx"},
	{0,NULL}
};
static const value_string last_data_frame_vals[] = {
	{0x000000,	"Last Data Frame - No Info"},
	{0x004000,	"Last Data Frame - Seq Imm"},
	{0x008000,	"Last Data Frame - Seq Soon"},
	{0x00c000,	"Last Data Frame - Seq Delyd"},
	{0,NULL}
};
static const value_string ack_0_1_vals[] = {
	{0x003000,	"ACK_0 Required"},
	{0x002000,	"ACK_0 Required"},
	{0x001000,	"ACK_1 Required"},
	{0x000000,	"no ack required"},
	{0,NULL}
};
static const true_false_string tfs_fc_fctl_exchange_responder = {
	"Exchange Responder",
	"Exchange Originator"
};
static const true_false_string tfs_fc_fctl_seq_recipient = {
	"Seq Recipient",
	"Seq Initiator"
};
static const true_false_string tfs_fc_fctl_exchange_first = {
	"Exchg First",
	"NOT exchg first"
};
static const true_false_string tfs_fc_fctl_exchange_last = {
	"Exchg Last",
	"NOT exchg last"
};
static const true_false_string tfs_fc_fctl_seq_last = {
	"Seq Last",
	"NOT seq last"
};
static const true_false_string tfs_fc_fctl_priority = {
	"Priority",
	"CS_CTL"
};
static const true_false_string tfs_fc_fctl_transfer_seq_initiative = {
	"Transfer Seq Initiative",
	"NOT transfer seq initiative"
};
static const true_false_string tfs_fc_fctl_rexmitted_seq = {
	"Retransmitted Sequence",
	"NOT retransmitted sequence"
};
static const true_false_string tfs_fc_fctl_rel_offset = {
	"Rel Offset SET",
	"rel offset NOT set"
};




/* code to dissect the  F_CTL bitmask */
static void
dissect_fc_fctl(packet_info *pinfo _U_, proto_tree *parent_tree, tvbuff_t *tvb, int offset, gboolean is_ack, guint32 fctl)
{
	proto_item *item;
	proto_tree *tree;
	gchar str[256];

        item=proto_tree_add_uint(parent_tree, hf_fc_fctl, tvb, offset, 3, fctl);
	tree=proto_item_add_subtree(item, ett_fctl);


	proto_tree_add_boolean(tree, hf_fc_fctl_exchange_responder, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_seq_recipient, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_exchange_first, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_exchange_last, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_seq_last, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_priority, tvb, offset, 3, fctl);

	proto_tree_add_boolean(tree, hf_fc_fctl_transfer_seq_initiative, tvb, offset, 3, fctl);

	proto_tree_add_uint(tree, hf_fc_fctl_last_data_frame, tvb, offset, 3, fctl);

	proto_tree_add_uint(tree, hf_fc_fctl_ack_0_1, tvb, offset, 3, fctl);


	proto_tree_add_boolean(tree, hf_fc_fctl_rexmitted_seq, tvb, offset, 3, fctl);

	if(is_ack){
		proto_tree_add_uint(tree, hf_fc_fctl_abts_ack, tvb, offset, 3, fctl);
	} else {
		proto_tree_add_uint(tree, hf_fc_fctl_abts_ack, tvb, offset, 3, fctl);
	}

	proto_tree_add_boolean(tree, hf_fc_fctl_rel_offset, tvb, offset, 3, fctl);

	fctl_to_str( ((guint8 *)&fctl), str, is_ack);
	proto_item_append_text(item, "  %s", str);
}

static const value_string fc_bls_proto_val[] = {
    {FC_BLS_NOP    , "NOP"},
    {FC_BLS_ABTS   , "ABTS"},
    {FC_BLS_RMC    , "RMC"},
    {FC_BLS_BAACC  , "BA_ACC"},
    {FC_BLS_BARJT  , "BA_RJT"},
    {FC_BLS_PRMT   , "PRMT"},
    {0, NULL},
};

static const value_string fc_els_proto_val[] = {
    {0x01    , "Solicited Data"},
    {0x02    , "Request"},
    {0x03    , "Reply"},
    {0, NULL},
};

/* Code to actually dissect the packets */
static void
dissect_fc_helper (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean is_ifcp)
{
   /* Set up structures needed to add the protocol subtree and manage it */
    proto_item *ti=NULL;
    proto_tree *fc_tree = NULL;
    tvbuff_t *next_tvb;
    int offset = 0, next_offset, eisl_offset = -1;
    gboolean is_lastframe_inseq, is_1frame_inseq, is_valid_frame;
    gboolean is_exchg_resp = 0;
    fragment_data *fcfrag_head;
    guint32 frag_id;
    guint32 frag_size;
    guint8 df_ctl, seq_id;
    
    guint32 param;
    guint16 real_seqcnt;
    guint8 ftype;
    gboolean is_ack;

    static fc_hdr fchdr;
    fc_exchange_data *fc_ex=NULL;

    conversation_t *conversation;
    fcseq_conv_data_t *cdata;
    fcseq_conv_key_t ckey, *req_key;

    fchdr.fced=NULL;

    /* Make entries in Protocol column and Info column on summary display */
    if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "FC");

    fchdr.r_ctl = tvb_get_guint8 (tvb, offset);

    /* If the R_CTL is the EISL field, skip the first 8 bytes to retrieve the
     * real FC header. EISL is Cisco-proprietary and is not decoded.
     */
    if (fchdr.r_ctl == FC_RCTL_EISL) {
        eisl_offset = offset;
        offset += 8;
        fchdr.r_ctl = tvb_get_guint8 (tvb, offset);
    }

    /* Each fc endpoint pair gets its own TCP session in iFCP but
     * the src/dst ids are undefined(==semi-random) in the FC header.
     * This means we can no track conversations for FC over iFCP by using
     * the FC src/dst addresses.
     * For iFCP: Do not update the pinfo src/dst struct and let it remain 
     * being tcpip src/dst so that request/response matching in the FCP layer
     * will use ip addresses instead and still work.
     */
    if(!is_ifcp){    
	SET_ADDRESS (&pinfo->dst, AT_FC, 3, tvb_get_ptr(tvb,offset+1,3));
	SET_ADDRESS (&pinfo->src, AT_FC, 3, tvb_get_ptr(tvb,offset+5,3));
	pinfo->srcport=0;
	pinfo->destport=0;
    }
    SET_ADDRESS (&fchdr.d_id, pinfo->dst.type, pinfo->dst.len, pinfo->dst.data);
    SET_ADDRESS (&fchdr.s_id, pinfo->src.type, pinfo->src.len, pinfo->src.data);

    fchdr.cs_ctl = tvb_get_guint8 (tvb, offset+4);
    fchdr.type  = tvb_get_guint8 (tvb, offset+8);
    fchdr.fctl=tvb_get_ntoh24(tvb,offset+9);
    fchdr.seqcnt = tvb_get_ntohs (tvb, offset+14);
    fchdr.oxid=tvb_get_ntohs(tvb,offset+16);
    fchdr.rxid=tvb_get_ntohs(tvb,offset+18);
    param = tvb_get_ntohl (tvb, offset+20);
    seq_id = tvb_get_guint8 (tvb, offset+12);

    pinfo->oxid = fchdr.oxid;
    pinfo->rxid = fchdr.rxid;
    pinfo->ptype = PT_EXCHG;
    pinfo->r_ctl = fchdr.r_ctl;

    is_ack = ((fchdr.r_ctl == 0xC0) || (fchdr.r_ctl == 0xC1));

    /* There are two ways to determine if this is the first frame of a
     * sequence. Either:
     * (i) The SOF bits indicate that this is the first frame OR
     * (ii) This is an SOFf frame and seqcnt is 0.
     */
    is_1frame_inseq = (((pinfo->sof_eof & PINFO_SOF_FIRST_FRAME) == PINFO_SOF_FIRST_FRAME) ||
                       (((pinfo->sof_eof & PINFO_SOF_SOFF) == PINFO_SOF_SOFF) &&
                        (fchdr.seqcnt == 0)));
    
    is_lastframe_inseq = ((pinfo->sof_eof & PINFO_EOF_LAST_FRAME) == PINFO_EOF_LAST_FRAME);

    if ((pinfo->sof_eof & PINFO_SOF_SOFF) == PINFO_SOF_SOFF) {
        is_lastframe_inseq = fchdr.fctl & FC_FCTL_SEQ_LAST;
    }
    is_valid_frame = ((pinfo->sof_eof & 0x40) == 0x40);

    ftype = fc_get_ftype (fchdr.r_ctl, fchdr.type);

    if (check_col (pinfo->cinfo, COL_INFO)) {
         col_add_str (pinfo->cinfo, COL_INFO, val_to_str (ftype, fc_ftype_vals,
                                                          "Unknown Type (0x%x)"));

        if (ftype == FC_FTYPE_LINKCTL)
            col_append_fstr (pinfo->cinfo, COL_INFO, ", %s",
                             val_to_str ((fchdr.r_ctl & 0x0F),
                                          fc_lctl_proto_val,
                                          "LCTL 0x%x"));
    }
    
    /* In the interest of speed, if "tree" is NULL, don't do any work not
       necessary to generate protocol tree items. */
    if (tree) {
        ti = proto_tree_add_protocol_format (tree, proto_fc, tvb, offset,
                                             FC_HEADER_SIZE, "Fibre Channel");
        fc_tree = proto_item_add_subtree (ti, ett_fc);
    }

    /* Highlight EISL header, if present */
    if (eisl_offset != -1) {
        proto_tree_add_item (fc_tree, hf_fc_eisl, tvb, eisl_offset, 8, 0);
    }

    /* match first exchange with last exchange */
    if(fchdr.fctl&FC_FCTL_EXCHANGE_FIRST){
        if(!pinfo->fd->flags.visited){
            fc_exchange_data fced, *old_fced;

            /* first check if we already have seen this exchange and it
               is still open/unmatched. 
            */
            fced.oxid=fchdr.oxid;
            SET_ADDRESS(&fced.s_id, fchdr.s_id.type, fchdr.s_id.len, fchdr.s_id.data);
            SET_ADDRESS(&fced.d_id, fchdr.d_id.type, fchdr.d_id.len, fchdr.d_id.data);
            old_fced=g_hash_table_lookup(fc_exchange_unmatched, &fced);
            if(old_fced){
                g_hash_table_remove(fc_exchange_unmatched, old_fced);
            }
            old_fced=g_mem_chunk_alloc(fc_exchange_vals);
            old_fced->oxid=fchdr.oxid;
            COPY_ADDRESS(&old_fced->s_id, &fchdr.s_id);
            COPY_ADDRESS(&old_fced->d_id, &fchdr.d_id);
	    old_fced->first_exchange_frame=pinfo->fd->num;
            old_fced->fc_time.nsecs = pinfo->fd->abs_usecs*1000;
            old_fced->fc_time.secs = pinfo->fd->abs_secs;
            g_hash_table_insert(fc_exchange_unmatched, old_fced, old_fced);
            fc_ex=old_fced;
        } else {
            fc_exchange_data fced, *old_fced;
            fced.oxid=fchdr.oxid;
            fced.first_exchange_frame=pinfo->fd->num;
            fced.last_exchange_frame=0;
            old_fced=g_hash_table_lookup(fc_exchange_matched, &fced);
            fc_ex=old_fced;
        }
    }
    if(fchdr.fctl&FC_FCTL_EXCHANGE_LAST){
        if(!pinfo->fd->flags.visited){
            fc_exchange_data fced, *old_fced;

            fced.oxid=fchdr.oxid;
            SET_ADDRESS(&fced.s_id, fchdr.d_id.type, fchdr.d_id.len, fchdr.d_id.data);
            SET_ADDRESS(&fced.d_id, fchdr.s_id.type, fchdr.s_id.len, fchdr.s_id.data);
            old_fced=g_hash_table_lookup(fc_exchange_unmatched, &fced);
            if(old_fced){
                g_hash_table_remove(fc_exchange_unmatched, old_fced);
                old_fced->last_exchange_frame=pinfo->fd->num;
                g_hash_table_insert(fc_exchange_matched, old_fced, old_fced);
            }
            fc_ex=old_fced;
        } else {
            fc_exchange_data fced, *old_fced;
            fced.oxid=fchdr.oxid;
            fced.first_exchange_frame=0;
            fced.last_exchange_frame=pinfo->fd->num;
            old_fced=g_hash_table_lookup(fc_exchange_matched, &fced);
            fc_ex=old_fced;
        }
    }
    if(fc_ex){
        if(fchdr.fctl&FC_FCTL_EXCHANGE_FIRST){
            proto_tree_add_uint(fc_tree, hf_fc_exchange_last_frame, tvb, 0, 0, fc_ex->last_exchange_frame);
        }
        if(fchdr.fctl&FC_FCTL_EXCHANGE_LAST){
            nstime_t delta_time;
            proto_tree_add_uint(fc_tree, hf_fc_exchange_first_frame, tvb, 0, 0, fc_ex->first_exchange_frame);
            delta_time.secs = pinfo->fd->abs_secs - fc_ex->fc_time.secs;
            delta_time.nsecs = pinfo->fd->abs_usecs*1000 - fc_ex->fc_time.nsecs;
            if (delta_time.nsecs<0){
                delta_time.nsecs+=1000000000;
                delta_time.secs--;
            }
            proto_tree_add_time(ti, hf_fc_time, tvb, 0, 0, &delta_time);
        }
    }
    fchdr.fced=fc_ex;

    switch (fchdr.r_ctl & 0xF0) {

    case FC_RCTL_DEV_DATA:
    case FC_RCTL_LINK_DATA:
    case FC_RCTL_VIDEO:
        /* the lower 4 bits of R_CTL are the information category */
        proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.r_ctl,
                                    "R_CTL: 0x%x(%s/%s)",
                                    fchdr.r_ctl,
                                    val_to_str ((fchdr.r_ctl & 0xF0),
                                                fc_routing_val, "0x%x"),
                                    val_to_str ((fchdr.r_ctl & 0x0F),
                                                fc_iu_val, "0x%x")); 
        break;

    case FC_RCTL_LINK_CTL:
        /* the lower 4 bits of R_CTL indicate the type of link ctl frame */
        proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.r_ctl,
                                    "R_CTL: 0x%x(%s/%s)",
                                    fchdr.r_ctl,
                                    val_to_str ((fchdr.r_ctl & 0xF0),
                                                fc_routing_val, "0x%x"),
                                    val_to_str ((fchdr.r_ctl & 0x0F),
                                                fc_lctl_proto_val, "0x%x")); 
        break;

    case FC_RCTL_BLS:
        switch (fchdr.type) {

        case 0x00:
            /* the lower 4 bits of R_CTL indicate the type of BLS frame */
            proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.r_ctl,
                                        "R_CTL: 0x%x(%s/%s)",
                                        fchdr.r_ctl,
                                        val_to_str ((fchdr.r_ctl & 0xF0),
                                                    fc_routing_val, "0x%x"),
                                        val_to_str ((fchdr.r_ctl & 0x0F),
                                                    fc_bls_proto_val, "0x%x")); 
            break;

        default:
            proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.r_ctl,
                                        "R_CTL: 0x%x(%s/0x%x)",
                                        fchdr.r_ctl,
                                        val_to_str ((fchdr.r_ctl & 0xF0),
                                                    fc_routing_val, "0x%x"),
                                        fchdr.r_ctl & 0x0F);
            break;
        }
        break;

    case FC_RCTL_ELS:
        switch (fchdr.type) {

        case 0x01:
            /* the lower 4 bits of R_CTL indicate the type of ELS frame */
            proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.r_ctl,
                                        "R_CTL: 0x%x(%s/%s)",
                                        fchdr.r_ctl,
                                        val_to_str ((fchdr.r_ctl & 0xF0),
                                                    fc_routing_val, "0x%x"),
                                        val_to_str ((fchdr.r_ctl & 0x0F),
                                                    fc_els_proto_val, "0x%x")); 
            break;

        default:
            proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.r_ctl,
                                        "R_CTL: 0x%x(%s/0x%x)",
                                        fchdr.r_ctl,
                                        val_to_str ((fchdr.r_ctl & 0xF0),
                                                    fc_routing_val, "0x%x"),
                                        fchdr.r_ctl & 0x0F);
            break;
        }
        break;

    default:
        proto_tree_add_uint_format (fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.r_ctl,
                                    "R_CTL: 0x%x(%s/0x%x)",
                                    fchdr.r_ctl,
                                    val_to_str ((fchdr.r_ctl & 0xF0),
                                                fc_routing_val, "0x%x"),
                                    fchdr.r_ctl & 0x0F);
        break;
    }
  
    proto_tree_add_uint_hidden (fc_tree, hf_fc_ftype, tvb, offset, 1,
                           ftype); 

    /* XXX - use "fc_wka_vals[]" on this? */
    proto_tree_add_string (fc_tree, hf_fc_did, tvb, offset+1, 3,
                           fc_to_str (fchdr.d_id.data));
    proto_tree_add_string_hidden (fc_tree, hf_fc_id, tvb, offset+1, 3,
                           fc_to_str (fchdr.d_id.data));

    proto_tree_add_uint (fc_tree, hf_fc_csctl, tvb, offset+4, 1, fchdr.cs_ctl);

    /* XXX - use "fc_wka_vals[]" on this? */
    proto_tree_add_string (fc_tree, hf_fc_sid, tvb, offset+5, 3,
                           fc_to_str (fchdr.s_id.data));
    proto_tree_add_string_hidden (fc_tree, hf_fc_id, tvb, offset+5, 3,
                           fc_to_str (fchdr.s_id.data));
        
    if (ftype == FC_FTYPE_LINKCTL) {
        if (((fchdr.r_ctl & 0x0F) == FC_LCTL_FBSYB) ||
            ((fchdr.r_ctl & 0x0F) == FC_LCTL_FBSYL)) {
            /* for F_BSY frames, the upper 4 bits of the type field specify the
             * reason for the BSY.
             */
            proto_tree_add_uint_format (fc_tree, hf_fc_type, tvb,
                                        offset+8, FC_TYPE_SIZE,
                                        fchdr.type,"Type: 0x%x(%s)", fchdr.type, 
                                        fclctl_get_typestr ((guint8) (fchdr.r_ctl & 0x0F),
                                                            fchdr.type));
        } else {
            proto_tree_add_item (fc_tree, hf_fc_type, tvb, offset+8, 1, FALSE);
        }
    } else {
        proto_tree_add_item (fc_tree, hf_fc_type, tvb, offset+8, 1, FALSE);
    }


    dissect_fc_fctl(pinfo, fc_tree, tvb, offset+9, is_ack, fchdr.fctl);


    proto_tree_add_item (fc_tree, hf_fc_seqid, tvb, offset+12, 1, FALSE);

    df_ctl = tvb_get_guint8(tvb, offset+13);

    proto_tree_add_uint (fc_tree, hf_fc_dfctl, tvb, offset+13, 1, df_ctl);
    proto_tree_add_uint (fc_tree, hf_fc_seqcnt, tvb, offset+14, 2, fchdr.seqcnt);
    proto_tree_add_uint (fc_tree, hf_fc_oxid, tvb, offset+16, 2, fchdr.oxid);
    proto_tree_add_uint (fc_tree, hf_fc_rxid, tvb, offset+18, 2, fchdr.rxid);

    if (ftype == FC_FTYPE_LINKCTL) {
        if (((fchdr.r_ctl & 0x0F) == FC_LCTL_FRJT) ||
            ((fchdr.r_ctl & 0x0F) == FC_LCTL_PRJT) ||
            ((fchdr.r_ctl & 0x0F) == FC_LCTL_PBSY)) {
            /* In all these cases of Link Ctl frame, the parameter field
             * encodes the detailed error message
             */
            proto_tree_add_uint_format (fc_tree, hf_fc_param, tvb,
                                        offset+20, 4, param,
                                        "Parameter: 0x%x(%s)", param,
                                        fclctl_get_paramstr ((fchdr.r_ctl & 0x0F),
                                                             param));
        } else {
            proto_tree_add_item (fc_tree, hf_fc_param, tvb, offset+20, 4, FALSE);
        }
    } else if (ftype == FC_FTYPE_BLS) {
        if ((fchdr.r_ctl & 0x0F) == FC_BLS_ABTS) {
            proto_tree_add_uint_format (fc_tree, hf_fc_param, tvb,
                                        offset+20, 4, param, 
                                        "Parameter: 0x%x(%s)", param,
                                        ((param & 0x0F) == 1 ? "Abort Sequence" :
                                         "Abort Exchange"));
        } else {
            proto_tree_add_item (fc_tree, hf_fc_param, tvb, offset+20,
                                 4, FALSE);
        }
    } else {
        proto_tree_add_item (fc_tree, hf_fc_param, tvb, offset+20, 4, FALSE);
    }

    /* Skip the Frame_Header */
    next_offset = offset + FC_HEADER_SIZE;

    /* Network_Header present? */
    if (df_ctl & FC_DFCTL_NH) {
        /* Yes - dissect it. */
        if (tree) {
            proto_tree_add_string (fc_tree, hf_fc_nh_da, tvb, next_offset, 8,
                                   fcwwn_to_str (tvb_get_ptr (tvb, offset, 8)));
            proto_tree_add_string (fc_tree, hf_fc_nh_sa, tvb, offset+8, 8,
                                   fcwwn_to_str (tvb_get_ptr (tvb, offset+8, 8)));
        }
        next_offset += 16;
    }

    /* XXX - handle Association_Header and Device_Header here */

    if (ftype == FC_FTYPE_LINKCTL) {
        /* ACK_1 frames and other LINK_CTL frames echo the last seq bit if the
         * packet they're ack'ing did not have it set. So, we'll incorrectly
         * flag them as being fragmented when they're not. This fixes the
         * problem
         */
        is_lastframe_inseq = TRUE;
    } else {
	/* XXX is this right?   offset 20, shouldnt it be offset 9? */
        is_exchg_resp = ((tvb_get_guint8 (tvb, offset+20) & 0x80) == 0x80);
    }

    if (tvb_reported_length (tvb) <= FC_HEADER_SIZE)
        THROW(ReportedBoundsError);

    frag_size = tvb_reported_length (tvb)-FC_HEADER_SIZE;

    /* If there is an MDS header, we need to subtract the MDS trailer size */
    if ((pinfo->ethertype == ETHERTYPE_UNK) || (pinfo->ethertype == ETHERTYPE_FCFT)) {
        if (frag_size <= MDSHDR_TRAILER_SIZE)
	    THROW(ReportedBoundsError);
        frag_size -= MDSHDR_TRAILER_SIZE;
    } else if (pinfo->ethertype == ETHERTYPE_BRDWALK) {
        if (frag_size <= 8)
	    THROW(ReportedBoundsError);
        frag_size -= 8;         /* 4 byte of FC CRC +
                                   4 bytes of error+EOF = 8 bytes  */
    }

    if (!is_lastframe_inseq) {
        /* Show this only as a fragmented FC frame */
        if (check_col (pinfo->cinfo, COL_INFO)) {
            col_append_str (pinfo->cinfo, COL_INFO, " (Fragmented)");
        }
    }

    /* If this is a fragment, attempt to check if fully reassembled frame is
     * present, if we're configured to reassemble.
     */
    if ((ftype != FC_FTYPE_LINKCTL) && (ftype != FC_FTYPE_BLS) &&
        (!is_lastframe_inseq || !is_1frame_inseq) && fc_reassemble &&
        tvb_bytes_exist(tvb, FC_HEADER_SIZE, frag_size) && tree) {
        /* Add this to the list of fragments */

        /* In certain cases such as FICON, the SEQ_CNT is streaming
         * i.e. continuously increasing. So, zero does not signify the
         * first frame of the sequence. To fix this, we need to save the
         * SEQ_CNT of the first frame in sequence and use this value to
         * determine the actual offset into a frame.
         */
        conversation = find_conversation (pinfo->fd->num, &pinfo->src, &pinfo->dst,
                                          pinfo->ptype, pinfo->oxid,
                                          pinfo->rxid, NO_PORT2);
        if (!conversation) {
            conversation = conversation_new (pinfo->fd->num, &pinfo->src, &pinfo->dst,
                                             pinfo->ptype, pinfo->oxid,
                                             pinfo->rxid, NO_PORT2);
        }
        
        ckey.conv_idx = conversation->index;
        
        cdata = (fcseq_conv_data_t *)g_hash_table_lookup (fcseq_req_hash,
                                                          &ckey);

        if (is_1frame_inseq) {
            if (cdata) {
                /* Since we never free the memory used by an exchange, this maybe a
                 * case of another request using the same exchange as a previous
                 * req. 
                 */
                cdata->seq_cnt = fchdr.seqcnt;
            }
            else {
                req_key = g_mem_chunk_alloc (fcseq_req_keys);
                req_key->conv_idx = conversation->index;
                
                cdata = g_mem_chunk_alloc (fcseq_req_vals);
                cdata->seq_cnt = fchdr.seqcnt;
                
                g_hash_table_insert (fcseq_req_hash, req_key, cdata);
            }
            real_seqcnt = 0;
        }
        else if (cdata != NULL) {
            real_seqcnt = fchdr.seqcnt - cdata->seq_cnt ;
        }
        else {
            real_seqcnt = fchdr.seqcnt;
        }

        /* Verify that this is a valid fragment */
        if (is_lastframe_inseq && !is_1frame_inseq && !real_seqcnt) {
             /* This is a frame that purports to be the last frame in a
              * sequence, is not the first frame, but has a seqcnt that is
              * 0. This is a bogus frame, don't attempt to reassemble it.
              */
             next_tvb = tvb_new_subset (tvb, next_offset, -1, -1);
             if (check_col (pinfo->cinfo, COL_INFO)) {
                  col_append_str (pinfo->cinfo, COL_INFO, " (Bogus Fragment)");
             }
        } else {
        
             frag_id = ((pinfo->oxid << 16) ^ seq_id) | is_exchg_resp ;

             /* We assume that all frames are of the same max size */
             fcfrag_head = fragment_add (tvb, FC_HEADER_SIZE, pinfo, frag_id,
                                         fc_fragment_table,
                                         real_seqcnt * fc_max_frame_size,
                                         frag_size,
                                         !is_lastframe_inseq);
             
             if (fcfrag_head) {
                  next_tvb = tvb_new_real_data (fcfrag_head->data,
                                                fcfrag_head->datalen,
                                                fcfrag_head->datalen);
                  tvb_set_child_real_data_tvbuff(tvb, next_tvb);
                  
                  /* Add the defragmented data to the data source list. */
            add_new_data_source(pinfo, next_tvb, "Reassembled FC");
            
            if (tree) {
                 proto_tree_add_boolean_hidden (fc_tree, hf_fc_reassembled,
                                                tvb, offset+9, 1, 1);
            }
             }
             else {
                  if (tree) {
                       proto_tree_add_boolean_hidden (fc_tree, hf_fc_reassembled,
                                                      tvb, offset+9, 1, 0);
            }
                  next_tvb = tvb_new_subset (tvb, next_offset, -1, -1);
                  call_dissector (data_handle, next_tvb, pinfo, tree);
                  return;
             }
        }
    } else {
        if (tree) {
            proto_tree_add_boolean_hidden (fc_tree, hf_fc_reassembled,
                                           tvb, offset+9, 1, 0);
        }
        next_tvb = tvb_new_subset (tvb, next_offset, -1, -1);
    }

    if ((ftype != FC_FTYPE_LINKCTL) && (ftype != FC_FTYPE_BLS)) {
	/* If relative offset is used, only dissect the pdu with
	 * offset 0 (param) */
	if( (fchdr.fctl&FC_FCTL_REL_OFFSET) && param ){
            call_dissector (data_handle, next_tvb, pinfo, tree);
	} else {
	    if (!dissector_try_port (fcftype_dissector_table, ftype, 
				next_tvb, pinfo, tree)) {
	        call_dissector (data_handle, next_tvb, pinfo, tree);
            }
        }
    } else if (ftype == FC_FTYPE_BLS) {
        if ((fchdr.r_ctl & 0x0F) == FC_BLS_BAACC) {
            dissect_fc_ba_acc (next_tvb, pinfo, tree);
        } else if ((fchdr.r_ctl & 0x0F) == FC_BLS_BARJT) {
            dissect_fc_ba_rjt (next_tvb, pinfo, tree);
        }
    }

    tap_queue_packet(fc_tap, pinfo, &fchdr);
}

static void
dissect_fc (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    dissect_fc_helper (tvb, pinfo, tree, FALSE);
}
static void
dissect_fc_ifcp (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    dissect_fc_helper (tvb, pinfo, tree, TRUE);
}

/* Register the protocol with Ethereal */

/* this format is require because a script is used to build the C function
   that calls all the protocol registration.
*/

void
proto_register_fc(void)
{                 

/* Setup list of header fields  See Section 1.6.1 for details*/
    static hf_register_info hf[] = {
        { &hf_fc_rctl,
          { "R_CTL", "fc.r_ctl", FT_UINT8, BASE_HEX, NULL, 0x0,
            "R_CTL", HFILL }},
        { &hf_fc_ftype,
          {"Frame type", "fc.ftype", FT_UINT8, BASE_HEX, VALS(fc_ftype_vals),
           0x0, "Derived Type", HFILL}},
        { &hf_fc_did,
          { "Dest Addr", "fc.d_id", FT_STRING, BASE_HEX, NULL, 0x0,
            "Destination Address", HFILL}},
        { &hf_fc_csctl,
          {"CS_CTL", "fc.cs_ctl", FT_UINT8, BASE_HEX, NULL, 0x0,
           "CS_CTL", HFILL}},
        { &hf_fc_sid,
          {"Src Addr", "fc.s_id", FT_STRING, BASE_HEX, NULL, 0x0,
           "Source Address", HFILL}},
        { &hf_fc_id,
          {"Addr", "fc.id", FT_STRING, BASE_HEX, NULL, 0x0,
           "Source or Destination Address", HFILL}},
        { &hf_fc_type,
          {"Type", "fc.type", FT_UINT8, BASE_HEX, VALS (fc_fc4_val), 0x0,
           "", HFILL}},
        { &hf_fc_fctl,
          {"F_CTL", "fc.f_ctl", FT_UINT24, BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_fc_seqid,
          {"SEQ_ID", "fc.seq_id", FT_UINT8, BASE_HEX, NULL, 0x0,
           "Sequence ID", HFILL}},
        { &hf_fc_dfctl,
          {"DF_CTL", "fc.df_ctl", FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_fc_seqcnt,
          {"SEQ_CNT", "fc.seq_cnt", FT_UINT16, BASE_DEC, NULL, 0x0,
           "Sequence Count", HFILL}},
        { &hf_fc_oxid,
          {"OX_ID", "fc.ox_id", FT_UINT16, BASE_HEX, NULL, 0x0, "Originator ID",
           HFILL}},
        { &hf_fc_rxid,
          {"RX_ID", "fc.rx_id", FT_UINT16, BASE_HEX, NULL, 0x0, "Receiver ID",
           HFILL}},
        { &hf_fc_param,
          {"Parameter", "fc.parameter", FT_UINT32, BASE_HEX, NULL, 0x0, "Parameter",
           HFILL}},

        { &hf_fc_reassembled,
          {"Reassembled Frame", "fc.reassembled", FT_BOOLEAN, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_fc_nh_da,
          {"Network DA", "fc.nethdr.da", FT_STRING, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_fc_nh_sa,
          {"Network SA", "fc.nethdr.sa", FT_STRING, BASE_HEX, NULL,
           0x0, "", HFILL}},

        /* Basic Link Svc field definitions */
        { &hf_fc_bls_seqid_vld,
          {"SEQID Valid", "fc.bls_seqidvld", FT_UINT8, BASE_HEX,
           VALS (fc_bls_seqid_val), 0x0, "", HFILL}},
        { &hf_fc_bls_lastvld_seqid,
          {"Last Valid SEQID", "fc.bls_lastseqid", FT_UINT8, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_fc_bls_oxid,
          {"OXID", "fc.bls_oxid", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_fc_bls_rxid,
          {"RXID", "fc.bls_rxid", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_fc_bls_lowseqcnt,
          {"Low SEQCNT", "fc.bls_lseqcnt", FT_UINT16, BASE_HEX, NULL, 0x0, "",
           HFILL}},
        { &hf_fc_bls_hiseqcnt,
          {"High SEQCNT", "fc.bls_hseqcnt", FT_UINT16, BASE_HEX, NULL, 0x0, "",
           HFILL}},
        { &hf_fc_bls_rjtcode,
          {"Reason", "fc.bls_reason", FT_UINT8, BASE_HEX, VALS(fc_bls_barjt_val),
           0x0, "", HFILL}},
        { &hf_fc_bls_rjtdetail,
          {"Reason Explanantion", "fc.bls_rjtdetail", FT_UINT8, BASE_HEX,
           VALS (fc_bls_barjt_det_val), 0x0, "", HFILL}},
        { &hf_fc_bls_vendor,
          {"Vendor Unique Reason", "fc.bls_vnduniq", FT_UINT8, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_fc_fctl_exchange_responder,
          {"ExgRpd", "fc.fctl.exchange_responder", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_exchange_responder),
           FC_FCTL_EXCHANGE_RESPONDER, "Exchange Responder?", HFILL}},
        { &hf_fc_fctl_seq_recipient,
          {"SeqRec", "fc.fctl.seq_recipient", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_seq_recipient),
           FC_FCTL_SEQ_RECIPIENT, "Seq Recipient?", HFILL}},
        { &hf_fc_fctl_exchange_first,
          {"ExgFst", "fc.fctl.exchange_first", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_exchange_first),
           FC_FCTL_EXCHANGE_FIRST, "First Exchange?", HFILL}},
        { &hf_fc_fctl_exchange_last,
          {"ExgLst", "fc.fctl.exchange_last", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_exchange_last),
           FC_FCTL_EXCHANGE_LAST, "Last Exchange?", HFILL}},
        { &hf_fc_fctl_seq_last,
          {"SeqLst", "fc.fctl.seq_last", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_seq_last),
           FC_FCTL_SEQ_LAST, "Last Sequence?", HFILL}},
        { &hf_fc_fctl_priority,
          {"Pri", "fc.fctl.priority", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_priority),
           FC_FCTL_PRIORITY, "Priority", HFILL}},
        { &hf_fc_fctl_transfer_seq_initiative,
          {"TSI", "fc.fctl.transfer_seq_initiative", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_transfer_seq_initiative),
           FC_FCTL_TRANSFER_SEQ_INITIATIVE, "Transfer Seq Initiative", HFILL}},
        { &hf_fc_fctl_rexmitted_seq,
          {"RetSeq", "fc.fctl.rexmitted_seq", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_rexmitted_seq),
           FC_FCTL_REXMITTED_SEQ, "Retransmitted Sequence", HFILL}},
        { &hf_fc_fctl_rel_offset,
          {"RelOff", "fc.fctl.rel_offset", FT_BOOLEAN, 24, TFS(&tfs_fc_fctl_rel_offset),
           FC_FCTL_REL_OFFSET, "rel offset", HFILL}},
        { &hf_fc_fctl_last_data_frame,
          {"LDF", "fc.fctl.last_data_frame", FT_UINT24, BASE_HEX, VALS(last_data_frame_vals),
           FC_FCTL_LAST_DATA_FRAME_MASK, "Last Data Frame?", HFILL}},
        { &hf_fc_fctl_ack_0_1,
          {"A01", "fc.fctl.ack_0_1", FT_UINT24, BASE_HEX, VALS(ack_0_1_vals),
           FC_FCTL_ACK_0_1_MASK, "Ack 0/1 value", HFILL}},
        { &hf_fc_fctl_abts_ack,
          {"AA", "fc.fctl.abts_ack", FT_UINT24, BASE_HEX, VALS(abts_ack_vals),
           FC_FCTL_ABTS_MASK, "ABTS ACK values", HFILL}},
        { &hf_fc_fctl_abts_not_ack,
          {"AnA", "fc.fctl.abts_not_ack", FT_UINT24, BASE_HEX, VALS(abts_not_ack_vals),
           FC_FCTL_ABTS_MASK, "ABTS not ACK vals", HFILL}},
        { &hf_fc_exchange_first_frame,
          { "Exchange First In", "fc.exchange_first_frame", FT_FRAMENUM, BASE_NONE, NULL,
           0, "The first frame of this exchange is in this frame", HFILL }},
        { &hf_fc_exchange_last_frame,
          { "Exchange Last In", "fc.exchange_last_frame", FT_FRAMENUM, BASE_NONE, NULL,
           0, "The last frame of this exchange is in this frame", HFILL }},
        { &hf_fc_time,
          { "Time from Exchange First", "fc.time", FT_RELATIVE_TIME, BASE_NONE, NULL,
           0, "Time since the first frame of the Exchange", HFILL }},
        { &hf_fc_eisl,
          {"EISL Header", "fc.eisl", FT_BYTES, BASE_HEX, NULL, 0, "EISL Header", HFILL}},
    };

    /* Setup protocol subtree array */
    static gint *ett[] = {
        &ett_fc,
        &ett_fcbls,
	&ett_fctl
    };

    module_t *fc_module;

    /* Register the protocol name and description */
    proto_fc = proto_register_protocol ("Fibre Channel", "FC", "fc");
    register_dissector ("fc", dissect_fc, proto_fc);
    register_dissector ("fc_ifcp", dissect_fc_ifcp, proto_fc);
    fc_tap = register_tap("fc");

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

    fcftype_dissector_table = register_dissector_table ("fc.ftype",
                                                        "FC Frame Type",
                                                        FT_UINT8, BASE_HEX);

    /* Register preferences */
    fc_module = prefs_register_protocol (proto_fc, NULL);
    prefs_register_bool_preference (fc_module,
                                    "reassemble",
                                    "Reassemble multi-frame sequences",
                                    "If enabled, reassembly of multi-frame "
                                    "sequences is done",
                                    &fc_reassemble);
    prefs_register_uint_preference (fc_module,
                                    "max_frame_size", "Max FC Frame Size",
                                    "This is the size of non-last frames in a "
                                    "multi-frame sequence", 10,
                                    &fc_max_frame_size);
    
    register_init_routine(fc_defragment_init);
    register_init_routine (fc_exchange_init_protocol);
}


/* If this dissector uses sub-dissector registration add a registration routine.
   This format is required because a script is used to find these routines and
   create the code that calls these routines.
*/
void
proto_reg_handoff_fc (void)
{
    data_handle = find_dissector("data");
}
