/* 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
 *
 * $Id$
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <glib.h>

#include <epan/packet.h>
#include <epan/exceptions.h>
#include <epan/prefs.h>
#include <epan/reassemble.h>
#include <epan/conversation.h>
#include <epan/etypes.h>
#include "packet-scsi.h"
#include "packet-fc.h"
#include "packet-fclctl.h"
#include "packet-fcbls.h"
#include <epan/tap.h>
#include <epan/wmem/wmem.h>
#include <epan/crc32-tvb.h>
#include <epan/expert.h>

#define FC_HEADER_SIZE         24
#define FC_RCTL_VFT            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_relative_offset = -1;

/* VFT fields */
static int hf_fc_vft = -1;
static int hf_fc_vft_rctl = -1;
static int hf_fc_vft_ver = -1;
static int hf_fc_vft_type = -1;
static int hf_fc_vft_pri = -1;
static int hf_fc_vft_vf_id = -1;
static int hf_fc_vft_hop_ct = -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;

/* For FC SOF */
static int proto_fcsof = -1;

static int hf_fcsof = -1;
static int hf_fceof = -1;
static int hf_fccrc = -1;

static int ett_fcsof = -1;
static int ett_fceof = -1;
static int ett_fccrc = -1;


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

static expert_field ei_fccrc = EI_INIT;

static dissector_handle_t fc_handle, fcsof_handle;
static dissector_table_t fcftype_dissector_table;

static dissector_handle_t data_handle;

static int fc_tap = -1;

typedef struct _fc_conv_data_t {
    wmem_tree_t *exchanges;
} fc_conv_data_t;


/* Reassembly stuff */
static gboolean fc_reassemble = TRUE;
static guint32  fc_max_frame_size = 1024;
static reassembly_table fc_reassembly_table;

typedef struct _fcseq_conv_key {
    guint32 conv_idx;
} fcseq_conv_key_t;

typedef struct _fcseq_conv_data {
    guint32 seq_cnt;
} fcseq_conv_data_t;

static GHashTable *fcseq_req_hash = NULL;

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

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

static guint
fcseq_hash (gconstpointer v)
{
    const fcseq_conv_key_t *key = (const fcseq_conv_key_t *)v;
    guint val;

    val = key->conv_idx;

    return val;
}

static void
fc_exchange_init_protocol(void)
{
    reassembly_table_init(&fc_reassembly_table,
                          &addresses_reassembly_table_functions);

    if (fcseq_req_hash)
        g_hash_table_destroy(fcseq_req_hash);

    fcseq_req_hash = g_hash_table_new(fcseq_hash, fcseq_equal);
}


const value_string fc_fc4_val[] = {
    {FC_TYPE_BLS,        "Basic Link Svc"},
    {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"},
    {FC_FTYPE_OHMS,      "OHMS(Cisco MDS)"},
    {0, NULL}
};

static const value_string fc_wka_vals[] _U_ = {
    {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}
};


/* For FC SOF */
#define    FC_SOFC1  0xBCB51717
#define    FC_SOFI1  0xBCB55757
#define    FC_SOFN1  0xBCB53737
#define    FC_SOFI2  0xBCB55555
#define    FC_SOFN2  0xBCB53535
#define    FC_SOFI3  0xBCB55656
#define    FC_SOFN3  0xBCB53636
#define    FC_SOFC4  0xBCB51919
#define    FC_SOFI4  0xBCB55959
#define    FC_SOFN4  0xBCB53939
#define    FC_SOFF   0xBCB55858

#define    EOFT_NEG    0xBC957575
#define    EOFT_POS    0xBCB57575
#define    EOFDT_NEG   0xBC959595
#define    EOFDT_POS   0xBCB59595
#define    EOFA_NEG    0xBC95F5F5
#define    EOFA_POS    0xBCB5F5F5
#define    EOFN_NEG    0xBC95D5D5
#define    EOFN_POS    0xBCB5D5D5
#define    EOFNI_NEG   0xBC8AD5D5
#define    EOFNI_POS   0xBCAAD5D5
#define    EOFDTI_NEG  0xBC8A9595
#define    EOFDTI_POS  0xBCAA9595
#define    EOFRT_NEG   0xBC959999
#define    EOFRT_POS   0xBCB59999
#define    EOFRTI_NEG  0xBC8A9999
#define    EOFRTI_POS  0xBCAA9999

static const value_string fc_sof_vals[] = {
    {FC_SOFC1, "SOFc1 - SOF Connect Class 1 (Obsolete)" },
    {FC_SOFI1, "SOFi1 - SOF Initiate Class 1 (Obsolete)" },
    {FC_SOFN1, "SOFn1 - SOF Normal Class 1 (Obsolete)" },
    {FC_SOFI2, "SOFi2 - SOF Initiate Class 2" },
    {FC_SOFN2, "SOFn2 - SOF Normal Class 2" },
    {FC_SOFI3, "SOFi3 - SOF Initiate Class 3" },
    {FC_SOFN3, "SOFn3 - SOF Normal Class 3" },
    {FC_SOFC4, "SOFc4 - SOF Activate Class 4 (Obsolete)" },
    {FC_SOFI4, "SOFi4 - SOF Initiate Class 4 (Obsolete)" },
    {FC_SOFN4, "SOFn4 - SOF Normal Class 4 (Obsolete)" },
    {FC_SOFF,  "SOFf - SOF Fabric" },
    {0, NULL}
};

static const value_string fc_eof_vals[] = {
    {EOFT_NEG,   "EOFt- - EOF Terminate" },
    {EOFT_POS,   "EOFt+ - EOF Terminate" },
    {EOFDT_NEG,  "EOFdt- - EOF Disconnect-Terminate-Class 1 (Obsolete)" },
    {EOFDT_POS,  "EOFdt+ - EOF Disconnect-Terminate-Class 1 (Obsolete)" },
    {EOFA_NEG,   "EOFa- - EOF Abort" },
    {EOFA_POS,   "EOFa+ - EOF Abort" },
    {EOFN_NEG,   "EOFn- - EOF Normal" },
    {EOFN_POS,   "EOFn+ - EOF Normal" },
    {EOFNI_NEG,  "EOFni- - EOF Normal Invalid" },
    {EOFNI_POS,  "EOFni+ - EOF Normal Invalid" },
    {EOFDTI_NEG, "EOFdti- - EOF Disconnect-Terminate-Invalid Class 1 (Obsolete)" },
    {EOFDTI_POS, "EOFdti+ - EOF Disconnect-Terminate-Invalid Class 1 (Obsolete)" },
    {EOFRT_NEG,  "EOFrt- - EOF Remove-Terminate Class 4 (Obsolete)" },
    {EOFRT_POS,  "EOFrt+ - EOF Remove-Terminate Class 4 (Obsolete)" },
    {EOFRTI_NEG, "EOFrti- - EOF Remove-Terminate Invalid Class 4 (Obsolete)" },
    {EOFRTI_POS, "EOFrti+ - EOF Remove-Terminate Invalid Class 4 (Obsolete)" },
    {0, NULL}
};

/* 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 */
    col_set_str(pinfo->cinfo, COL_PROTOCOL, "BLS");

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

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 */
    col_set_str(pinfo->cinfo, COL_PROTOCOL, "BLS");

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

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;
        case FC_TYPE_VENDOR:
             return FC_FTYPE_OHMS;
        default:
            return FC_FTYPE_UNDEF;
        }
    case FC_RCTL_ELS:
        if (((r_ctl & 0x0F) == 0x2) || ((r_ctl & 0x0F) == 0x3))
            return FC_FTYPE_ELS;
        else if (type == FC_TYPE_ELS)
            return FC_FTYPE_OHMS;
        else
             return FC_FTYPE_UNDEF;
    case FC_RCTL_LINK_DATA:
        switch (type) {
        case FC_TYPE_SCSI:
            return FC_FTYPE_SCSI;
        default:
            return FC_FTYPE_LINKDATA;
        }
    case FC_RCTL_VIDEO:
        return FC_FTYPE_VDO;
    case FC_RCTL_BLS:
        if (type == 0)
            return FC_FTYPE_BLS;
        else
            return FC_FTYPE_UNDEF;
    case FC_RCTL_LINK_CTL:
        return FC_FTYPE_LINKCTL;
    default:
        return FC_FTYPE_UNDEF;
    }
}

static const value_string abts_ack_vals[] = {
    {0x000000,  "ABTS - Cont"},
    {0x000010,  "ABTS - Abort"},
    {0x000020,  "ABTS - Stop"},
    {0x000030,  "ABTS - Imm Seq Retx"},
    {0,NULL}
};
#if 0
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}
};
#endif
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"
};

/*
 * Dissect the VFT header.
 */
static void
dissect_fc_vft(proto_tree *parent_tree,
                tvbuff_t *tvb, int offset)
{
    proto_item *item = NULL;
    proto_tree *tree = NULL;
    guint8 rctl;
    guint8 ver;
    guint8 type;
    guint8 pri;
    guint16 vf_id;
    guint8 hop_ct;

    rctl = tvb_get_guint8(tvb, offset);
    type = tvb_get_guint8(tvb, offset + 1);
    ver = (type >> 6) & 3;
    type = (type >> 2) & 0xf;
    vf_id = tvb_get_ntohs(tvb, offset + 2);
    pri = (vf_id >> 13) & 7;
    vf_id = (vf_id >> 1) & 0xfff;
    hop_ct = tvb_get_guint8(tvb, offset + 4);

    if (parent_tree) {
        item = proto_tree_add_uint_format_value(parent_tree, hf_fc_vft, tvb, offset,
                                    8, vf_id, "VF_ID %d Pri %d Hop Count %d",
                                    vf_id, pri, hop_ct);
        tree = proto_item_add_subtree(item, ett_fc_vft);
    }
    proto_tree_add_uint(tree, hf_fc_vft_rctl, tvb, offset, 1, rctl);
    proto_tree_add_uint(tree, hf_fc_vft_ver, tvb, offset + 1, 1, ver);
    proto_tree_add_uint(tree, hf_fc_vft_type, tvb, offset + 1, 1, type);
    proto_tree_add_uint(tree, hf_fc_vft_pri, tvb, offset + 2, 1, pri);
    proto_tree_add_uint(tree, hf_fc_vft_vf_id, tvb, offset + 2, 2, vf_id);
    proto_tree_add_uint(tree, hf_fc_vft_hop_ct, tvb, offset + 4, 1, hop_ct);
}

/* 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)
{
    proto_item *item=NULL;
    proto_tree *tree=NULL;
    guint32 flags;

    flags = tvb_get_guint8 (tvb, offset);
    flags = (flags<<8) | tvb_get_guint8 (tvb, offset+1);
    flags = (flags<<8) | tvb_get_guint8 (tvb, offset+2);

    if(parent_tree){
        item=proto_tree_add_uint(parent_tree, hf_fc_fctl, tvb, offset, 3, flags);
        tree=proto_item_add_subtree(item, ett_fctl);
    }

    proto_tree_add_boolean(tree, hf_fc_fctl_exchange_responder, tvb, offset, 3, flags);
    if (flags&FC_FCTL_EXCHANGE_RESPONDER){
        proto_item_append_text(item, " Exchange Responder");
        if (flags & (~( FC_FCTL_EXCHANGE_RESPONDER )))
            proto_item_append_text(item, ",");
    } else {
        proto_item_append_text(item, " Exchange Originator");
        if (flags & (~( FC_FCTL_EXCHANGE_RESPONDER )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_EXCHANGE_RESPONDER ));

    proto_tree_add_boolean(tree, hf_fc_fctl_seq_recipient, tvb, offset, 3, flags);
    if (flags&FC_FCTL_SEQ_RECIPIENT){
        proto_item_append_text(item, " Seq Recipient");
        if (flags & (~( FC_FCTL_SEQ_RECIPIENT )))
            proto_item_append_text(item, ",");
    } else {
        proto_item_append_text(item, " Seq Initiator");
        if (flags & (~( FC_FCTL_SEQ_RECIPIENT )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_SEQ_RECIPIENT ));

    proto_tree_add_boolean(tree, hf_fc_fctl_exchange_first, tvb, offset, 3, flags);
    if (flags&FC_FCTL_EXCHANGE_FIRST){
        proto_item_append_text(item, " Exchg First");
        if (flags & (~( FC_FCTL_EXCHANGE_FIRST )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_EXCHANGE_FIRST ));

    proto_tree_add_boolean(tree, hf_fc_fctl_exchange_last, tvb, offset, 3, flags);
    if (flags&FC_FCTL_EXCHANGE_LAST){
        proto_item_append_text(item, " Exchg Last");
        if (flags & (~( FC_FCTL_EXCHANGE_LAST )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_EXCHANGE_LAST ));

    proto_tree_add_boolean(tree, hf_fc_fctl_seq_last, tvb, offset, 3, flags);
    if (flags&FC_FCTL_SEQ_LAST){
        proto_item_append_text(item, " Seq Last");
        if (flags & (~( FC_FCTL_SEQ_LAST )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_SEQ_LAST ));

    proto_tree_add_boolean(tree, hf_fc_fctl_priority, tvb, offset, 3, flags);
    if (flags&FC_FCTL_PRIORITY){
        proto_item_append_text(item, " Priority");
        if (flags & (~( FC_FCTL_PRIORITY )))
            proto_item_append_text(item, ",");
    } else {
        proto_item_append_text(item, " CS_CTL");
        if (flags & (~( FC_FCTL_PRIORITY )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_PRIORITY ));

    proto_tree_add_boolean(tree, hf_fc_fctl_transfer_seq_initiative, tvb, offset, 3, flags);
    if (flags&FC_FCTL_TRANSFER_SEQ_INITIATIVE){
        proto_item_append_text(item, " Transfer Seq Initiative");
        if (flags & (~( FC_FCTL_TRANSFER_SEQ_INITIATIVE )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_TRANSFER_SEQ_INITIATIVE ));

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

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

    proto_tree_add_boolean(tree, hf_fc_fctl_rexmitted_seq, tvb, offset, 3, flags);
    if (flags&FC_FCTL_REXMITTED_SEQ){
        proto_item_append_text(item, " Rexmitted Seq");
        if (flags & (~( FC_FCTL_REXMITTED_SEQ )))
            proto_item_append_text(item, ",");
    }
    flags&=(~( FC_FCTL_REXMITTED_SEQ ));

    proto_tree_add_uint(tree, hf_fc_fctl_abts_ack, tvb, offset, 3, flags);

    proto_tree_add_boolean(tree, hf_fc_fctl_rel_offset, tvb, offset, 3, flags);
    if (flags&FC_FCTL_REL_OFFSET){
        proto_item_append_text(item, " Rel Offset");
        if (flags & (~( FC_FCTL_REL_OFFSET )))
            proto_item_append_text(item, ",");
    }

}

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, *hidden_item;
    proto_tree *fc_tree = NULL;
    tvbuff_t *next_tvb;
    int offset = 0, next_offset;
    int vft_offset = -1;
    gboolean is_lastframe_inseq, is_1frame_inseq/*, is_valid_frame*/;
    gboolean is_exchg_resp = 0;
    fragment_head *fcfrag_head;
    guint32 frag_id;
    guint32 frag_size;
    guint8 df_ctl, seq_id;
    guint32 f_ctl;

    guint32 param;
    guint16 real_seqcnt;
    guint8 ftype;
    /*gboolean is_ack;*/

    static fc_hdr fchdr;
    itlq_nexus_t *fc_ex=NULL;
    fc_conv_data_t *fc_conv_data=NULL;

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

    fchdr.itlq=NULL;

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

    fchdr.r_ctl = tvb_get_guint8 (tvb, offset);

    /*
     * If the frame contains a VFT (virtual fabric tag), decode it
     * as a separate header before the FC frame header.
     *
     * This used to be called the Cisco-proprietary EISL field, but is now
     * standardized in FC-FS-2.  See section 10.2.4.
     */
    if (fchdr.r_ctl == FC_RCTL_VFT) {
        vft_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){
        TVB_SET_ADDRESS (&pinfo->dst, AT_FC, tvb, offset+1, 3);
        TVB_SET_ADDRESS (&pinfo->src, AT_FC, 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);
    fchdr.relative_offset=0;
    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;

    /* set up a conversation and conversation data */
    /* TODO treat the fc address  s_id==00.00.00 as a wildcard matching anything */
    conversation=find_or_create_conversation(pinfo);
    fc_conv_data=(fc_conv_data_t *)conversation_get_proto_data(conversation, proto_fc);
    if(!fc_conv_data){
        fc_conv_data=wmem_new(wmem_file_scope(), fc_conv_data_t);
        fc_conv_data->exchanges=wmem_tree_new(wmem_file_scope());
        conversation_add_proto_data(conversation, proto_fc, fc_conv_data);
    }

    /* set up the exchange data */
    /* XXX we should come up with a way to handle when the 16bit oxid wraps
     * so that large traces will work
     */
    fc_ex=(itlq_nexus_t *)wmem_tree_lookup32(fc_conv_data->exchanges, fchdr.oxid);
    if(!fc_ex){
        fc_ex=wmem_new(wmem_file_scope(), itlq_nexus_t);
        fc_ex->first_exchange_frame=0;
        fc_ex->last_exchange_frame=0;
        fc_ex->lun=0xffff;
        fc_ex->scsi_opcode=0xffff;
        fc_ex->task_flags=0;
        fc_ex->data_length=0;
        fc_ex->bidir_data_length=0;
        fc_ex->fc_time=pinfo->fd->abs_ts;
        fc_ex->flags=0;
        fc_ex->alloc_len=0;
        fc_ex->extra_data=NULL;
        wmem_tree_insert32(fc_conv_data->exchanges, fchdr.oxid, fc_ex);
    }
    /* populate the exchange struct */
    if(!pinfo->fd->flags.visited){
        if(fchdr.fctl&FC_FCTL_EXCHANGE_FIRST){
            fc_ex->first_exchange_frame=pinfo->fd->num;
            fc_ex->fc_time = pinfo->fd->abs_ts;
        }
        if(fchdr.fctl&FC_FCTL_EXCHANGE_LAST){
            fc_ex->last_exchange_frame=pinfo->fd->num;
        }
    }


    /* 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);
    }

    /* put some nice exchange data in the tree */
    if(!(fchdr.fctl&FC_FCTL_EXCHANGE_FIRST)){
        proto_item *it;
        it=proto_tree_add_uint(fc_tree, hf_fc_exchange_first_frame, tvb, 0, 0, fc_ex->first_exchange_frame);
        PROTO_ITEM_SET_GENERATED(it);
        if(fchdr.fctl&FC_FCTL_EXCHANGE_LAST){
            nstime_t delta_ts;
            nstime_delta(&delta_ts, &pinfo->fd->abs_ts, &fc_ex->fc_time);
            it=proto_tree_add_time(ti, hf_fc_time, tvb, 0, 0, &delta_ts);
            PROTO_ITEM_SET_GENERATED(it);
        }
    }
    if(!(fchdr.fctl&FC_FCTL_EXCHANGE_LAST)){
        proto_item *it;
        it=proto_tree_add_uint(fc_tree, hf_fc_exchange_last_frame, tvb, 0, 0, fc_ex->last_exchange_frame);
        PROTO_ITEM_SET_GENERATED(it);
    }

    fchdr.itlq=fc_ex;

    /*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);

    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);

    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"));

    if (vft_offset >= 0) {
        dissect_fc_vft(fc_tree, tvb, vft_offset);
    }
    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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                        FC_RCTL_SIZE, fchdr.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_value(fc_tree, hf_fc_rctl, tvb, offset,
                                    FC_RCTL_SIZE, fchdr.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;
    }

    hidden_item = proto_tree_add_uint (fc_tree, hf_fc_ftype, tvb, offset, 1,
                                       ftype);
    PROTO_ITEM_SET_HIDDEN(hidden_item);

    /* XXX - use "fc_wka_vals[]" on this? */
    proto_tree_add_string (fc_tree, hf_fc_did, tvb, offset+1, 3,
                           fc_to_str ((const guint8 *)fchdr.d_id.data));
    hidden_item = proto_tree_add_string (fc_tree, hf_fc_id, tvb, offset+1, 3,
                                         fc_to_str ((const guint8 *)fchdr.d_id.data));
    PROTO_ITEM_SET_HIDDEN(hidden_item);

    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 ((const guint8 *)fchdr.s_id.data));
    hidden_item = proto_tree_add_string (fc_tree, hf_fc_id, tvb, offset+5, 3,
                                         fc_to_str ((const guint8 *)fchdr.s_id.data));
    PROTO_ITEM_SET_HIDDEN(hidden_item);

    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_value(fc_tree, hf_fc_type, tvb,
                                        offset+8, FC_TYPE_SIZE,
                                        fchdr.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, ENC_BIG_ENDIAN);
        }
    } else {
        proto_tree_add_item (fc_tree, hf_fc_type, tvb, offset+8, 1, ENC_BIG_ENDIAN);
    }


    dissect_fc_fctl(pinfo, fc_tree, tvb, offset+9);
    f_ctl = tvb_get_ntoh24(tvb, offset+9);


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

    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_value(fc_tree, hf_fc_param, tvb,
                                        offset+20, 4, param,
                                        "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, ENC_BIG_ENDIAN);
        }
    } else if (ftype == FC_FTYPE_BLS) {
        if ((fchdr.r_ctl & 0x0F) == FC_BLS_ABTS) {
            proto_tree_add_uint_format_value(fc_tree, hf_fc_param, tvb,
                                        offset+20, 4, param,
                                        "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, ENC_BIG_ENDIAN);
        }
    } else if (ftype == FC_FTYPE_SCSI ) {
        if (f_ctl&FC_FCTL_REL_OFFSET){
            proto_tree_add_item (fc_tree, hf_fc_relative_offset, tvb, offset+20, 4, ENC_BIG_ENDIAN);
            fchdr.relative_offset=tvb_get_ntohl(tvb, offset+20);
        } else {
            proto_tree_add_item (fc_tree, hf_fc_param, tvb, offset+20, 4, ENC_BIG_ENDIAN);
        }
    } else {
        proto_tree_add_item (fc_tree, hf_fc_param, tvb, offset+20, 4, ENC_BIG_ENDIAN);
    }

    /* 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_string (wmem_packet_scope(), tvb, offset, 8)));
            proto_tree_add_string (fc_tree, hf_fc_nh_sa, tvb, offset+8, 8,
                                   fcwwn_to_str (tvb_get_string (wmem_packet_scope(), 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 {
        is_exchg_resp = (f_ctl & FC_FCTL_EXCHANGE_RESPONDER) != 0;
    }

    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
     * Link Ctl, BLS & OHMS are all (encap header + FC Header + encap trailer)
     * and are never fragmented and so we ignore the frag_size assertion for
     *  these frames.
     */
    if ((pinfo->ethertype == ETHERTYPE_UNK) || (pinfo->ethertype == ETHERTYPE_FCFT)) {
        if ((frag_size < MDSHDR_TRAILER_SIZE) ||
            ((frag_size == MDSHDR_TRAILER_SIZE) && (ftype != FC_FTYPE_LINKCTL) &&
             (ftype != FC_FTYPE_BLS) && (ftype != FC_FTYPE_OHMS)))
            THROW(ReportedBoundsError);
        frag_size -= MDSHDR_TRAILER_SIZE;
    } else if (pinfo->ethertype == ETHERTYPE_BRDWALK) {
        if ((frag_size <= 8) ||
            ((frag_size == MDSHDR_TRAILER_SIZE) && (ftype != FC_FTYPE_LINKCTL) &&
             (ftype != FC_FTYPE_BLS) && (ftype != FC_FTYPE_OHMS)))
            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 */
        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) &&
        (ftype != FC_FTYPE_OHMS) &&
        (!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.
         */
        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 = wmem_new(wmem_file_scope(), fcseq_conv_key_t);
                req_key->conv_idx = conversation->index;

                cdata = wmem_new(wmem_file_scope(), fcseq_conv_data_t);
                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_remaining (tvb, next_offset);
             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 (&fc_reassembly_table,
                                         tvb, FC_HEADER_SIZE,
                                         pinfo, frag_id, NULL,
                                         real_seqcnt * fc_max_frame_size,
                                         frag_size,
                                         !is_lastframe_inseq);

             if (fcfrag_head) {
                  next_tvb = tvb_new_chain(tvb, fcfrag_head->tvb_data);

                  /* Add the defragmented data to the data source list. */
                  add_new_data_source(pinfo, next_tvb, "Reassembled FC");

                  if (tree) {
                      hidden_item = proto_tree_add_boolean (fc_tree, hf_fc_reassembled,
                                                            tvb, offset+9, 1, 1);
                      PROTO_ITEM_SET_HIDDEN(hidden_item);
                  }
             }
             else {
                  if (tree) {
                       hidden_item = proto_tree_add_boolean (fc_tree, hf_fc_reassembled,
                                                             tvb, offset+9, 1, 0);
                       PROTO_ITEM_SET_HIDDEN(hidden_item);
            }
                  next_tvb = tvb_new_subset_remaining (tvb, next_offset);
                  call_dissector (data_handle, next_tvb, pinfo, tree);
                  return;
             }
        }
    } else {
        if (tree) {
            hidden_item = proto_tree_add_boolean (fc_tree, hf_fc_reassembled,
                                                  tvb, offset+9, 1, 0);
            PROTO_ITEM_SET_HIDDEN(hidden_item);
        }
        next_tvb = tvb_new_subset_remaining (tvb, next_offset);
    }

    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_uint_new (fcftype_dissector_table, ftype,
                                next_tvb, pinfo, tree, FALSE, &fchdr)) {
                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);
        } else if ((fchdr.r_ctl & 0x0F) == FC_BLS_ABTS) {
            col_set_str(pinfo->cinfo, COL_PROTOCOL, "BLS");
            col_set_str(pinfo->cinfo, COL_INFO, "ABTS");
        }
    }
    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);
}

static void
dissect_fcsof(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {

    proto_item *it = NULL;
    proto_tree *fcsof_tree = NULL;
    gint bytes_remaining;
    tvbuff_t *next_tvb, *checksum_tvb;
    guint32 sof = 0;
    guint32 crc = 0;
    guint32 crc_computed = 0;
    guint32 eof = 0;
    gint crc_offset = 0;
    gint eof_offset = 0;
    gint sof_offset = 0;
    const gint FCSOF_TRAILER_LEN = 8;
    const gint FCSOF_HEADER_LEN = 4;
    gint frame_len_for_checksum = 0;

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

    crc_offset = tvb_reported_length(tvb) - FCSOF_TRAILER_LEN;
    eof_offset = crc_offset + 4;
    sof_offset = 0;

    /* Get SOF */
    sof = tvb_get_ntohl(tvb, 0);

    /* GET CRC */
    crc = tvb_get_ntohl(tvb, crc_offset);

    /* GET Computed CRC */
    frame_len_for_checksum = crc_offset - FCSOF_HEADER_LEN;
    checksum_tvb = tvb_new_subset(tvb, 4, frame_len_for_checksum, frame_len_for_checksum);
    crc_computed = crc32_802_tvb(checksum_tvb, frame_len_for_checksum);

    /* Get EOF */
    eof = tvb_get_ntohl(tvb, eof_offset);

    it = proto_tree_add_protocol_format(tree, proto_fcsof, tvb, 0,
                                        4, "Fibre Channel Delimiter: SOF: %s EOF: %s",
                                        val_to_str(sof, fc_sof_vals, "0x%x"),
                                        val_to_str(eof, fc_eof_vals, "0x%x"));

    fcsof_tree = proto_item_add_subtree(it, ett_fcsof);

    proto_tree_add_uint(fcsof_tree, hf_fcsof, tvb, sof_offset, 4, sof);

    if (crc == crc_computed) {
        proto_tree_add_uint_format_value(fcsof_tree, hf_fccrc, tvb,
                                       crc_offset, 4, crc,
                                       "%8.8x [valid]", crc);
    } else {
        it = proto_tree_add_uint_format_value(fcsof_tree, hf_fccrc, tvb,
                                       crc_offset, 4, crc,
                                       "%8.8x [error: should be %8.8x]",
                                       crc, crc_computed);

        expert_add_info_format(pinfo, it, &ei_fccrc,
                                   "Bad FC CRC %8.8x %8.x",
                                   crc, crc_computed);
    }

    proto_tree_add_uint(fcsof_tree, hf_fceof, tvb, eof_offset, 4, eof);

    bytes_remaining = tvb_length_remaining(tvb, 4);
    next_tvb = tvb_new_subset(tvb, 4, bytes_remaining, -1);

    pinfo->sof_eof = 0;
    if (sof == FC_SOFI2 || sof == FC_SOFI3) {
        pinfo->sof_eof = PINFO_SOF_FIRST_FRAME;
    } else if (sof == FC_SOFF) {
        pinfo->sof_eof = PINFO_SOF_SOFF;
    }

    if (eof == EOFT_POS || eof == EOFT_NEG) {
        pinfo->sof_eof |= PINFO_EOF_LAST_FRAME;
    } else if (eof == EOFDTI_NEG || eof == EOFDTI_POS) {
        pinfo->sof_eof |= PINFO_EOF_INVALID;
    }

    /* Call FC dissector */
    call_dissector(fc_handle, next_tvb, pinfo, tree);
}

/* Register the protocol with Wireshark */

/* 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,
            NULL, 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_NONE, NULL, 0x0,
            "Destination Address", HFILL}},
        { &hf_fc_csctl,
          {"CS_CTL", "fc.cs_ctl", FT_UINT8, BASE_HEX, NULL, 0x0,
           NULL, HFILL}},
        { &hf_fc_sid,
          {"Src Addr", "fc.s_id", FT_STRING, BASE_NONE, NULL, 0x0,
           "Source Address", HFILL}},
        { &hf_fc_id,
          {"Addr", "fc.id", FT_STRING, BASE_NONE, NULL, 0x0,
           "Source or Destination Address", HFILL}},
        { &hf_fc_type,
          {"Type", "fc.type", FT_UINT8, BASE_HEX, VALS (fc_fc4_val), 0x0,
           NULL, HFILL}},
        { &hf_fc_fctl,
          {"F_CTL", "fc.f_ctl", FT_UINT24, BASE_HEX, NULL, 0x0, NULL, 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, NULL, 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, NULL,
           HFILL}},

        { &hf_fc_reassembled,
          {"Reassembled Frame", "fc.reassembled", FT_BOOLEAN, BASE_NONE, NULL,
           0x0, NULL, HFILL}},
        { &hf_fc_nh_da,
          {"Network DA", "fc.nethdr.da", FT_STRING, BASE_NONE, NULL,
           0x0, NULL, HFILL}},
        { &hf_fc_nh_sa,
          {"Network SA", "fc.nethdr.sa", FT_STRING, BASE_NONE, NULL,
           0x0, NULL, 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, NULL, HFILL}},
        { &hf_fc_bls_lastvld_seqid,
          {"Last Valid SEQID", "fc.bls_lastseqid", FT_UINT8, BASE_HEX, NULL,
           0x0, NULL, HFILL}},
        { &hf_fc_bls_oxid,
          {"OXID", "fc.bls_oxid", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
        { &hf_fc_bls_rxid,
          {"RXID", "fc.bls_rxid", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
        { &hf_fc_bls_lowseqcnt,
          {"Low SEQCNT", "fc.bls_lseqcnt", FT_UINT16, BASE_HEX, NULL, 0x0, NULL,
           HFILL}},
        { &hf_fc_bls_hiseqcnt,
          {"High SEQCNT", "fc.bls_hseqcnt", FT_UINT16, BASE_HEX, NULL, 0x0, NULL,
           HFILL}},
        { &hf_fc_bls_rjtcode,
          {"Reason", "fc.bls_reason", FT_UINT8, BASE_HEX, VALS(fc_bls_barjt_val),
           0x0, NULL, HFILL}},
        { &hf_fc_bls_rjtdetail,
          {"Reason Explanation", "fc.bls_rjtdetail", FT_UINT8, BASE_HEX,
           VALS (fc_bls_barjt_det_val), 0x0, NULL, HFILL}},
        { &hf_fc_bls_vendor,
          {"Vendor Unique Reason", "fc.bls_vnduniq", FT_UINT8, BASE_HEX, NULL,
           0x0, NULL, 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}},
#if 0
        { &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}},
#endif
        { &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_relative_offset,
          {"Relative Offset", "fc.relative_offset", FT_UINT32, BASE_DEC, NULL,
           0, "Relative offset of data", HFILL}},
        { &hf_fc_vft,
          {"VFT Header", "fc.vft", FT_UINT16, BASE_DEC, NULL,
           0, NULL, HFILL}},
        { &hf_fc_vft_rctl,
          {"R_CTL", "fc.vft.rctl", FT_UINT8, BASE_HEX, NULL,
           0, NULL, HFILL}},
        { &hf_fc_vft_ver,
          {"Version", "fc.vft.ver", FT_UINT8, BASE_DEC, NULL,
           0, "Version of VFT header", HFILL}},
        { &hf_fc_vft_type,
          {"Type", "fc.vft.type", FT_UINT8, BASE_DEC, NULL,
           0, "Type of tagged frame", HFILL}},
        { &hf_fc_vft_pri,
          {"Priority", "fc.vft.type", FT_UINT8, BASE_DEC, NULL,
           0, "QoS Priority", HFILL}},
        { &hf_fc_vft_vf_id,
          {"VF_ID", "fc.vft.vf_id", FT_UINT16, BASE_DEC, NULL,
           0, "Virtual Fabric ID", HFILL}},
        { &hf_fc_vft_hop_ct,
          {"HopCT", "fc.vft.hop_ct", FT_UINT8, BASE_DEC, NULL,
           0, "Hop Count", HFILL}},
    };

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

    static ei_register_info ei[] = {
        { &ei_fccrc, { "fc.crc.bad", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
    };

    module_t *fc_module;
    expert_module_t* expert_fc;

    /* FC SOF */

    static hf_register_info sof_hf[] = {
        { &hf_fcsof,
          { "SOF", "fc.sof", FT_UINT32, BASE_HEX, VALS(fc_sof_vals), 0,
            NULL, HFILL }},
        { &hf_fceof,
          { "EOF", "fc.eof", FT_UINT32, BASE_HEX, VALS(fc_eof_vals), 0,
            NULL, HFILL }},
        { &hf_fccrc,
          { "CRC", "fc.crc", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }},
    };

    static gint *sof_ett[] = {
        &ett_fcsof,
        &ett_fceof,
        &ett_fccrc
    };


    /* Register the protocol name and description */
    proto_fc = proto_register_protocol ("Fibre Channel", "FC", "fc");
    fc_handle = 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));
    expert_fc = expert_register_protocol(proto_fc);
    expert_register_field_array(expert_fc, ei, array_length(ei));

    /* subdissectors called through this table will find the fchdr structure
     * through data parameter of dissector
     */
    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_exchange_init_protocol);


    /* Register FC SOF/EOF */
    proto_fcsof = proto_register_protocol("Fibre Channel Delimiters", "FCSoF", "fcsof");

    proto_register_field_array(proto_fcsof, sof_hf, array_length(sof_hf));
    proto_register_subtree_array(sof_ett, array_length(sof_ett));

    fcsof_handle = register_dissector("fcsof", dissect_fcsof, proto_fcsof);
}


/* 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)
{
    dissector_add_uint("wtap_encap", WTAP_ENCAP_FIBRE_CHANNEL_FC2, fc_handle);

    dissector_add_uint("wtap_encap", WTAP_ENCAP_FIBRE_CHANNEL_FC2_WITH_FRAME_DELIMS, fcsof_handle);

    data_handle = find_dissector("data");
}
